Europaisches Patentamt (19) European Patent Office Office europeenpeen des brevets EP 0 499 268 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention (51) intci.e: F02F 1/42, F02B 61/02 of the grant of the patent: 08.05.1996 Bulletin 1996/19

(21) Application number: 92102501.1

(22) Date of filing: 14.02.1992

(54) Multiple valve internal combustion engine Vielfachventilbrennkraftmaschine Moteur a combustion interne a multiples soupapes

(84) Designated Contracting States: (72) Inventors: DE ES FR GB IT Kaneko Mamoru 2500 Shingai Iwata-Shi Shizuoka-Ken 438 (JP) (30) Priority: 15.02.1991 JP 44310/91 Nonogawa Kenichi 2500 Shingai Iwata-Shi Shizuoka-Ken 438 (JP) (43) Date of publication of application: 19.08.1992 Bulletin 1992/34 (74) Representative: Griinecker, Kinkeldey, Stockmair & Schwanhausser Anwaltssozietat (73) Proprietor: YAMAHA HATSUDOKI KABUSHIKI Maximilianstrasse 58 KAISHA 80538 Miinchen (DE) Iwata-shi Shizuoka-ken, 438 (JP) (56) References cited: US-A- 4 627 400 US-A- 4 683 855

DO 00 CO CM O) O) ^- Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice the Patent Office of the Notice of shall be filed in o to European opposition to European patent granted. opposition a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. a. 99(1) European Patent Convention). LU Printed by Jouve, 75001 PARIS (FR) 1 EP 0 499 26858 B1 2

Description connecting passage is arranged perpendicularly with re- spect to the direction of flow of the fluid. The present invention relates the multiple valve in- Further examples of staged induction systems are ternal combustion engine comprising a head disclosed in US-A-4617896, US-A-4683855, JP-A- having at least three valves per cylinder and a s 61186726 and JP-A-62-93122. Moreover, by means of staged induction system having at least two intake pas- constructional measures attempts have already been sages serving the intake valve seat openings of the cyl- made to improve the volumetric efficiency of charging inder head and charge forming means and an intercon- the , providing a good turbulence necting passage connecting at least two of said intake and swirl action of the charge introduced therein (US-A- passages. 10 4971008, JP-A-63-25369, JP-A-1 -1 39079, JP-A- It is acknowledged that the performance of an inter- 1-95572, JP-A-62-12771, EP-A-430258, EP-A-430259, nal combustion engine can be improved, particularly at EP-A-430263). high speeds, by the use of multiple intake valves. Al- As such an intake device in which a swirl is obtain- though four valve per cylinder engines are quite com- able in a low engine speed region, there is known a de- mon, there are a number of advantages of employing 15 vice in which the above first to third intake valve open- five valve per cylinder with three intake valves. The ex- ings are led outward and connected at their midways to cellent breathing capacity of a five valve engine is well a common intake passage and in which one fuel injec- acknowledged. However, because of the good breath- tion valve is provided in the common intake passage and ing capacity of five valve engines, these engines may an open-close valve which is opened only in a high en- have a tendency to have poor performance at low and 20 gine speed stage is provided in one of the intake pas- mid-range speeds. The reason for this is that the flow sages, as described in Japanese Published Unexam- velocity through the three intake passages under these ined Utility Model Application No. Sho-61 -186726. running conditions is extremely low and poor combus- Moreover, an intake device has been proposed in tion and fuel vaporization can result. It has been, there- which a first intake passage in fluid communication with fore, been proposed to provide some staging system so 25 one of the above intake valve openings and a second that the effective intake area of the engine is reduced intake passage in fluid communication with the other, when operating at low and mid-range speeds. two intake valve openings are provided and in which a Although such staging systems significantly im- is independently provided in each of the first prove the performance of the engine at low speeds, they and second intake passages so that the air-fuel mixture do give rise to some difficulties. For example, if the stag- 30 is fed through the first intake passage only in a low en- ing is accomplished by providing a valve in each gine speed region but is fed through both of the first and intake passage, then the porting configu- second intake passages in a middle or high engine ration and throttle valve arrangement can become com- speed region (see, for example, Japanese Patent Ap- plicated. If, on the other hand, two of the intake passag- plication No. Hei-1 -309466). es are siamesed and the third is left separate and a th rot- 35 In addition to the porting considerations previously tie valve is provided only the siamesed passage, it has described, the use of multiple intake valves, particularly been noted that mid-range performance can deterio- if staging is employed, can give rise to certain difficulties rate. That is, it has been found with such an arrange- in connection with the associated charge forming sys- ment that there may be a dip in the torque curve of the tem. Specifically, if and specifically port fuel engine at mid-range. Since this is a commonly operated 40 injection is employed and a staged induction system is speed range for the engine, such an arrangement may also incorporated, then it is very difficult to utilize a single not be acceptable. fuel injector for spraying fuel into all of the intake pas- It has been discovered, however, that this problem sages. This can present some problems even if staging with mid-range performance can be overcome by pro- is not employed because it is difficult to position an in- viding at least some communication between the intake 45 jector and have its spray nozzle in such an orientation ports even though they are basically separated. How- to insure that a uniform mixture is supplied to the com- ever, this can present some problems in connection with bustion chamber under all running conditions. Alterna- the forming of the interconnecting passageway and tively, even if stratification is desired, the mixture alloca- keeping it close to the intake valve seats, where it is tion within the combustion chamber can be difficult. most effective so Therefore, the objective of the present invention to A multiple valve internal combustion engine of the provide a multiple valve internal combustion engine of type mentioned at the beginning is known from US-A-4 the defined on the preamble of claim 1, having an en- 627 400. In said prior art the interconnecting passage is hanced staged induction allowing improved swirl action arranged transversely to the intake passages, which of the intake charge specifically under mid range engine with respect to the direction of flow of the charge coming 55 running conditions in order to obtain an optimum per- from the carburettor causes fluid flowing though said in- formance of the engine under all running conditions. terconnecting passage to perform an overall 90° turn. According to the present invention the above objec- Moreover, in said known engine the inlet of said inter- tive is obtained by a multiple valve internal combustion

2 3 EP 0 499 268 B1 4 engine of the type defined in the preamble of claim 1 DETAILED DESCRIPTION OF THE PREFERRED wherein the interconnecting passage is disposed within EMBODIMENTS OF THE INVENTION the cylinder head extending adjacent to and towards a centre valve seat allowing the amount of the charge sup- Referring first to Figure 1 , a motorcycle powered by plied to said centre valve seat to be varied in response 5 an internal combustion engine constructed in accord- to the load conditions of the engine. ance with an embodiment of the invention is identified According to a preferred embodiment of the present generally by the reference numeral 21 . The invention is invention the cylinder head defines a combustion cham- described in conjunction with a motorcycle since it has ber and at least three intake valve seats therein and a particular utility in conjunction with such this type of ve- pair of separate inlet openings are formed, preferably in 10 hide. It is to be understood, however, that certain facets another surface of the cylinder head, and first and sec- of the invention may be utilized in conjunction with in- ond intake passages formed in the cylinder head extend ternal combustion engines that power other types of ve- from the respective one of said inlet openings to the hicles or, for that matter, other applications for internal valve seats wherein one side valve seat is served by the combustion engines. first intake passage while the other two valve seats, is The motorcycle 21 includes a welded frame assem- namely a center valve seat and another side valve seat bly 22 having a head pipe 23 that journals a front fork are served by the common Siamese type second intake 24 for steering movement. A front wheel (not shown) is passage. Moreover, the interconnection passage is pro- journaled by the front fork 24 in a known manner. vided to communicate both intake passages with each The frame 22 further includes a main frame tube 25, other adjacent the valve seats, specifically in the area 20 a down tube 26, a seat rail 27 and a seat pillar 28. At upstream of the centre valve seat. the lower end of the frame, an underguard 29 spans the Other preferred embodiments of the present inven- down tube 26 and the seat pillar 28. tion are set out in the set of subclaims. Afuel tank 31 is positioned behind the head pipe 23 The present invention it is explained in greater detail and ahead of a seat 32 that is carried by the seat rail 27. by means of several embodiments thereof in conjunc- 25 A small body assembly comprised of a side cover for tion with the accompanying drawings wherein: the tank 31 and air scoop 33, a side covering for the Figure 1 is a partial side elevational view of a mo- lower portion of the seat 34 and a rear cover 35 are suit- torcycle powered by an internal combustion engine con- ably affixed to the frame 22. structed in accordance with a first embodiment of the A trailing arm 36 suspends a rear wheel 37 from the invention. 30 frame assembly in a suitable manner, including a com- Figure 2 is a top plan view, with portions broken bined spring shock absorber 38 that lies generally on away, showing the cylinder head assembly of the en- the longitudinal center plane of the motorcycle 21 . gine, with the cam cover removed and with portions The rear wheel 37 is powered by an engine unit 39 shown in section. which is comprised of a water cooled, single cylinder, Figure 3 is a cross sectional view of the complete 35 four cycle, five valve, single overhead cam engine. A cylinder head assembly and a portion of the associated assembly 41 of the engine unit 39 contains cylinder block taken along the line 3-3 of Figure 2. a change speed transmission which is driven by the en- Figure 4 is a cross sectional view taken along the gine and which drives the rear wheel 37 line 4-4 of Figure 2. through a chain 42. Although the details of the engine Figure 5 is a cross sectional view of the cylinder 40 unit 39 and specifically the engine portion of it will be head taken through the intake and exhaust ports to described by references to the remaining figures, the show the configuration of their passages. engine unit 39 includes a cylinder head 43, a cam cover Figure 6 is a side elevational view of the cylinder 44 and a cylinder block 45 in addition to the crankcase head looking in the direction of the arrow 6 in Figure 1 41 . This engine unit is mounted in the frame 22 with the and showing the induction manifold removed. 45 cylinder block 45 inclined slightly forward in a suitable Figure 7 is a bottom plan view of the cylinder head manner by means including a support pipe 46 that is with the valves removed. positioned beneath the main pipe 25 and which is joined Figure 8 is an enlarged side elevational view show- to the main pipe 25 and the down tube 26. ing the relationship between the intake rocker arms and As will become apparent, the engine unit 39 has a the upper ends of the intake valve stems. so pair of forwardly facing exhaust ports from which a pair Figure 9 is a cross sectional view, in part similar to of exhaust pipes 47 and 48 extend into an exhaust sys- Figure 5 and shows another embodiment of the inven- tem, indicated generally by the reference numeral 49 tion. and which includes a side mounted 51 . Figure 1 0 is a cross sectional view, in part similar to The engine unit 39 also includes an induction sys- Figures 5 and 9, and shows yet another embodiment of 55 tern including an air box which is not shown in Figure 1 the invention. that supplies air to a pair of which serve three rearwardly facing exhaust ports, as will be de- scribed by reference to the remaining figures. The in-

3 5 EP 0 499 268 B1 6 duction system (Figure 5) includes a primary induction 67 are disposed at an angle to the plane containing the system 52 including a primary carburetor 53 and a sec- cylinder axis D and thus diverge from a plane per- ondary system 54 including a secondary carburetor 55. pendicular to this plane and also passing through the Both carburetors 53 and 55 draw air from the aforenoted cylinder bore axis D. This permits the exhaust pipes 47 air box. The configuration of the components is such that 5 and 48 to clear the down tube 26 and also provides a the exhaust pipes 47 and 48 extends on opposite sides better and less flow resistant path for the entire exhaust of the down tube 26 while the air box encircles the spring system. shock absorber unit 38 so as to provide a very compact A well 81 is formed in the cylinder head assembly and yet one which will not interfere with the 43 between the exhaust passages 66 and 67 and termi- basic construction of the motorcycle or adversely affect 10 nates at a threaded opening 82 in which a spark plug the design of the engine. 83 is received. The spark plug 83 is disposed so that its Referring now to Figures 3 and 4, it will be noted gap lies substantially on the cylinder bore axis D. A cor- that the cylinder block 45 is formed with a cylinder bore responding well 84 is formed in the cam cover 44 so as 59 which is formed by a pressed or cast in liner 61. A to facilitate insertion and removal of the spark plug 83 (not shown) reciprocates within the cylinder bore is without removing the cam cover 44. The spark plug 83 59 and drives the crankshaft (not shown) contained is fired by a suitable . within the crankcase 41 in a well known manner. Since A primary intake passage 85 extends through the the invention deals primarily with the cylinder head 43 opposite side of the cylinder head 43 from the exhaust and valve train associated with it, those components of side already described. The passage 85 extends from the engine which are considered to be conventional 20 an intake port 86 formed in the side of the cylinder head have not been illustrated and further description of them 43 and terminates at a valve seat 87 formed by a is not believed to be necessary to enable those skilled pressed in insert. As may be best seen in Figure 5, the in the art to practice the invention. primary intake passage 85 has a central axis that is gen- The cylinder head 43 has a lower surface 62 that is erally perpendicular to the aforenoted plane containing sealingly engaged with a 63 so as to pro- 25 the cylinder bore axis D and hence as a relatively short vide a seal with the cylinder block 45 around the cylinder length from its intake port 86 to its valve seat 87. As a bore 59. In addition, the cylinder head 43 is formed with result, good, low and mid range performance and good a generally central recess 64 which recess is defined by response nay be achieved. This passage 85 and its cen- a surface 65 surrounded by the lower cylinder head sur- tral axis is disposed at a distance from a plane which face 62. This recess has a generally spherical configu- 30 plane contains the axis of the cylinder bore D and is per- ration although it assumes a pent roof type of configu- pendicular to the aforenoted plane. The significance of ration as may be best seen in Figures 3 and 4. this will be as described. Referring now primarily to Figures 2 through 5, the A Siamese type secondary intake passage 88 ex- cylinder head 43 is formed with a pair of forwardly facing tends from an intake port 89 formed in the intake side exhaust passages 66 and 67 each of which extends 35 of the cylinder head 43 and branches into a pair of pas- from the combustion chamber 63 through a valve seat sages 91 and 92 each of which terminates at a respec- 68 formed by a pressed in insert 69. These exhaust pas- tive valve seat comprised of a center valve seat 93 and sages 66 and 67 terminate in forwardly facing exhaust a side valve seat 94. Said passages 91 and 92 define a ports 71 to which the respective exhaust pipes 47 and wedge shaped wall portion 300 projecting within an area 48 are affixed in a suitable manner. 40 between the center valve seat 93 and the side valve seat A pair of exhaust valves 72 each of which has a 94 commonly serviced by said second intake passage head portion 73 and a stem portion 74 are slideably sup- 88. Said wall portion 300 also serves for shielding the ported for reciprocation within the cylinder head 43 by side intake valve seat 94 from being supplied with a por- a respective pressed in valve guide 75. The exhaust tion of an air fuel charge fed through an interconnecting valves 72 reciprocate within a common plane that is in- 45 passage 148 which is oriented to the center valve seat clined at an acute angle to a plane containing the axis 93 and is explained later on. The center of the intake D (Figure 2) of the cylinder bore 59. The axes of recip- port 89 as extended by a spacer, to be described, is dis- rocation also lie in planes that are parallel to each other posed at a distance from the plane which distance is the and to the cylinder bore axis D. This facilitates operation same as the distance of the primary intake port 86. The of the valve although they may be slightly inclined if de- so carburetors 53 and 55 are affixed to these respective sired. The exhaust valves 72 are urged to their closed intake ports 86 and 89 through the intermediary of re- positions by means of respective coil compression spective spacers 95 and 96 (Figure 5) which have re- springs 76 that engage wear plates 77 bearing against spective passageways 97 and 98 that form extensions the cylinder head 43 and keeper retainer assemblies 78 of the cylinder head intake passages 85 and 88. By uti- affixed in a known manner to the upper ends of the ex- 55 lizing the spacers it is possible to have this equal dis- haust valve stems 74. The exhaust valves 72 are tance between the centers of the ports even though the opened in a manner which will be described. actual port 89 is closer to the perpendicular plane than It should be noted that the exhaust passages 66 and is the inlet of the passage 98 and its spacer. This con-

4 7 EP 0 499 268 B1 8 struction permits the induction system to clear the shock are each indicated by the reference numeral 1 09. Intake absorber and spring assembly 38 and avoids interfer- valve springs 111 engage bearing plates 112 that bear ence between the carburetors 53 and 55. against the cylinder head 43 and keeper retainer assem- A central effective line or bisector of the secondary blies 113 affixed to the upper ends of the respective intake passage 88 lies at an acute angle to the perpen- 5 valve stems for urging the intake valves 99, 101 and 1 02 dicular plane while the portion 92 extends generally per- to their closed positions. The intake valves 99, 101 and pendicularly to the plane containing the axis of the cyl- 102 are operated by means of assemblies inder bore D as aforenoted. to be described. The carburetor 53 is sized and jetted and has a The exhaust valves 72 and intake valves 99, 101 throttle valve (not shown) that functions to control both 10 and 1 02 are all operated by means of a single overhead the low speed and mid range performance of the engine 1 1 4. The camshaft 1 1 4 is journaled, in a man- as well as the high speed performance. The throttle ner to be described, for rotation about an axis E which valve (not shown) of the carburetor 55 is operated in a is offset to the intake side of the cylinder head from the staged sequence with the carburetor of the throttle valve cylinder bore axis D by a distance 01 (Figure 2). The 53 and the carburetor 55 may only have high speed cir- is axis E is parallel to the plane aforementioned that con- cuits since this carburetor supplies the fuel air charge tains the axis of the cylinder bore D. The camshaft 114 only to the engine under high speed operation. Either a has enOd bearing surfaces that are journaled in bearing staged linkage system or some form of load or speed surfaces 115 and 116 formed by the cylinder head 43 responsive control (such as a vacuum responsive servo and corresponding bearing surfaces formed by the cam motor) can be employed for operating the throttle valve 20 cover 44. In addition, there is provided a central bearing of the carburetor 55 in this staged sequence. surface on the camshaft 1 1 4 that is journaled by a bear- First, second and third poppet type intake valves 99, ing surface 117 formed in the cylinder head 43. A cor- 101 and 102 have respective head portions 103, 104 responding bearing surface is partially formed in the and 105 which cooperate with the valve seats 87, 93 cam cover 44 and has its center offset a distance 02 and 94 for controlling the flow through them. The intake 25 from the cylinder bore axis D so as to provide clearance valves 99 and 102 are side valves and have their re- for other components of the cylinder head assembly to spective stem portions 106 and 107 slidable supported be described and specifically one of the rocker arms. in guides, to be described, for reciprocation about axes The camshaft 114 is driven from the engine crank- B which are in a common plane disposed at an acute shaft by means of a drive chain (not shown) and sprock- angle (Figure 6) to the plane containing the cylinder bore 30 et 118 that is affixed to one end of the camshaft. A de- axis D which acute angle may be substantially the same compression device 1 1 9 is associated with the sprocket as the acute angle of reciprocation of the exhaust valves 118 and serves to reduce the starting torque on the en- 72. The center exhaust valve 101 has its stem portion gine by lifting slightly one of the exhaust valves 72 during 108 supported for reciprocation about an axis A which starting operation. is disposed also at an acute angle (Figure 6) to the 35 A pair of exhaust cam lobes 121 are formed at the aforenoted plane containing the cylinder bore axis D but outer ends of the camshaft 114 adjacent the bearings which acute angle is lesser than the angle of reciproca- that engage the cylinder head bearing surfaces 1 1 5 and tion B of the valves 99 and 101 . The angular disposition 1 1 6. These cam lobes 121 are engaged by follower sur- of the reciprocal axes A and B is such that these axes faces 122 of exhaust rocker arms 123. These exhaust intersect a line C which is parallel to the plane containing 40 rocker arms 1 23 are journaled on stub rocker arm shafts the cylinder bore axis D but which is spaced from the 124 each of which is supported by a respective boss tips of the individual intake valves 99, 101 and 102. As 125 formed on the inner surface of the cam cover 44. a result of this, the angular configuration of the side The outer ends of the rocker arms 1 23 are provided valves 99 and 1 02 relative to the center valve 1 01 is rel- with taped portions 126 that receive adjusting screws atively small. This configuration permits the adjacent 45 1 27 for providing lash adjustment between the exhaust area between the intake valves to be relatively smooth rocker arms 123 and he tips of the stems 74 of the ex- and thus provide a smooth combustion chamber config- haust valves 72 for clearance adjustment. Access open- uration that will avoid hot spots and still permit a gener- ings 1 28 are provided in the cam cover 44 for facilitating ally spherical configuration. valve adjustment without removal of the cam cover 44. The axes A and B of reciprocation of the intake so These access openings 1 28 are normally closed by clo- valves 101 and 99 and 1 02 all lie in parallel planes which sure plugs 129 which are affixed in place in a suitable planes are parallel to the axis of the cylinder bore D. manner. This permits ease of operation. However, if desired, In addition to the exhaust cam lobes 121, the cam- these axes may be slightly skewed from parallel planes shaft 114 is provided with a first intake cam lobe 131 as is also possible with the exhaust valves 72, as pre- 55 and a second intake cam lobe 1 32 which lobes 1 31 and viously noted. 1 32 are disposed on opposite sides of the central cam- The valve guides that slidable support the stems shaft bearing surface which is journaled in the cylinder 1 06, 1 07 and 1 08 of the intake valves 99, 1 02 and 1 01 head bearing surface 1 1 7. The cam lobes 1 31 and 1 32

5 9 EP 0 499 268 B1 10 cooperate with respective rocker arms 1 33 and 1 34 for 142 that receives an adjusting screw 143 that cooper- opening the intake valves 99, 101 and 102, respectively, ates with the tip of the stem 108 of the center intake in a manner to be described. The rocker arms 133 and valve 101 . The arm 141 has an enlarged taped portion 1 34 are both journaled on a single rocker arm shaft 1 35 144 that receives an adjusting screw 145 that cooper- that is journaled within the bearing surfaces formed by 5 ates with the tip of the valve stem 1 07 of the intake valve lugs 1 36 of the cam cover 44. These lugs 1 36 also form 102 for clearance adjustment. the bearing surfaces which cooperate with the cylinder The cam cover 44 is provided with elongated open- head bearing surfaces 115, 116 and 117 for journaling ing 1 46 for accessing each of the adjusting screws 1 38, the camshaft 114. 1 43 and 1 45 so that the valve adjustment may be made It has already been noted that the intake valves 99 10 without removing the cam cover. A removal closure plug and 102 reciprocate about respective reciprocal axes B 1 47 normally closes the opening 1 46 and is removed for and the intake valve 101 reciprocates about the axis A. servicing. As has been noted that the axes A and B intersect at a The cam lobe 1 32 associated with the rocker arm line C which is parallel to the aforenoted plane contain- assembly 134 is configured so as to provide a greater ing the cylinder bore axis D which point C is spaced from is degree of lift for both of the valves and also a longer the tips of all of the intake valves. The center intake valve event. This is because the rocker arm 1 34 is associated 101 has its tip spaced outwardly in a horizontal direction with the secondary or high speed intake passage 88 of a greater distance 12' than the tips of the side intake the cylinder head 43. As has also be noted, due to the valves 99 and 102 which valves lie at the distance 11' difference in length of the arms 1 39 and 1 41 the center from the plane and also from the pivotally axes of the 20 intake valve 101 may have an even greater lift than the respective rocker arms 133 and 134. Also, it should be side intake valve 102. This configuration may be done noted that the center intake valve 101 and specifically so as to improve or generate swirl in the combustion its axis B is at a perpendicular distance 1 1 from the rock- chamber. Of course and as has been previously noted, er arm shaft 113 whereas the axes of reciprocation A of those designers in the art may incorporate these fea- the other intake valves is a perpendicular distance 12 25 tures to provide different types of valve operation and from this axis. This distance 1 1 is less than the distance different types of tuning. 12. These differences in distance permit the smooth Although the use of the primary and secondary in- combustion chamber configuration previously noted take passages 85 and 88 permit a good volumetric effi- and also permit a variation in the amount of lift for the ciency for high speed running as well as good turbu- two valves operated from the same cam lobe and same 30 lence and combustion at low speed running due to the rocker arm, this being the cam lobe 132 and rocker am use of only the primary intake passage 87 under this 134 in this embodiment. As a result of the greater dis- condition, it has been found that when the passages 85 tance to the center intake valve 101 than the side intake and 86 do not communicate with each other, there may valves 99 and 102 a greater amount of lift may be be some fall off in mid-range torque. To avoid this dis- achieved for this valve than the other two. As a result, ss advantage, there is provide an interconnecting pas- there can be generated more air flow through the center sageway 148 (Figures 3, 4 and 5), which is generally a intake passage than the side intake passages. Although cylindrical passageway that extends between the prima- the tip of the center intake valves 1 01 is spaced different ry intake passage 85 and the secondary intake passage distances from the tips of the side intake valves 99 and 88 and specifically the portion 91 thereof. The passage- 1 02 from the rocker arm axis E and also from the cylin- 40 way 1 48 is disposed at an acute angle as shown in Fig- der bore axis D, the tips of all of the stems of the intake ure 5 to a plane perpendicular to the plane containing valves 99, 101 and 1 02 lie at substantially the same ver- the cylinder bore axis D so that the flow will be directed tical distance above the cylinder head sealing surface toward the passage 88 from the passage 85 and spe- 62 and lie in a common plane with the pivot axis of the cifically toward the center intake valve 101. This con- rocker arms 1 33 and 1 34. This is done so as to reduce 45 struction has been found to improve mid-range perform- the overall height of the cylinder head assembly and of ance and also to insure that there will not be any strat- the engine, as will be described. ification of the fuel air charge when operating at high Rocker arm 1 33 has an enlarged taped portion 1 37 speed high load conditions. The passageway 148 can that receives an adjusting screw 138 that cooperates be conveniently formed within the cylinder head 43 and with the tip of the stem 106 of the intake valve 99 that so is located so that it may be formed by drilling through is associated with the primary intake passage 85. As has the port opening 86, as should be readily apparent from been previously noted, the intake passage 85 is de- Figure 5. As a result, this passageway 148 can be po- signed primarily to accommodate low and mid range sitioned close to the valve seats 87 and 93 where it has performance and hence the cam lobe 131 may be con- been found to provide the greatest improvement in mid- figured to provide a lift characteristic that is better tuned 55 range performance. for low speed performance. Therefore, the interconnecting passageway 1 48 not The rocker arm 134 has a pair of bifurcated arms only improves mid-range performance but improves 139 and 141 with the arm 139 having a threaded end high speed performance due to the more homogeneous

6 11 EP 0 499 268 B1 12 fuel air mixture that will be charged in the combustion ingly the first fuel injector 201 is disposed such to align chamber due to the incorporation of this passageway. a longitudinal center axis X-, of its fuel jet being sprayed In the embodiment of the invention as thus far de- into the first intake passage 85 to a side area of the as- scribed (Figures 1 through 8) the charge forming system sociated side valve seat 87 with a portion of the fuel has been comprised of a pair of primary and secondary 5 spray entering the communicating passage 148 to be carburetors. However, the invention can also be utilized supplied to the center intake valve 1 01 . As already indi- with great efficiency in connection with fuel injection en- cated above with respect to Figure 5 said additional por- gines and Figure 9 shows such an embodiment. Except tion of the charge fed from the primary fuel injector 201 for the incorporation of fuel injectors, the construction of through the communicating passage 148 to the center the cylinder head and valves of this embodiment is the 10 valve seat 93 is prevented from reaching the right-side same as the embodiment of Figures 1 through 8 and, valve seat 94 due to the shielding wedge shaped wall for that reason, only a single figure is believed to be nec- projection 300 formed by the bifurcated portion of the essary to show the construction and operation of this secondary intake passage 88 and the resulting passag- embodiment. es 91 , 92. As shown in Figure 9, the wedge shaped pro- In this embodiment, a first or primary fuel injector 's jection 300 projects further in an upstream direction 201 is positioned either in the spacer 95 or the cylinder compared to the embodiment of Figure 5 and has a knife 43, the spacer mounting being illustrated. A secondary shaped tip with the secondary fuel injector 202 being fuel injector 202 is mounted in the spacer 96, but also disposed such that a longitudinal center axis X2 of the may be mounted in the cylinder head if so desired. A fuel jet sprayed into the secondary intake passage 88 common air ducting system, indicated generally by the 20 by said second fuel injector 202 is aligned with said tip reference numeral 203 in which a manually operated pri- of the projecting wall portion 300 of the cylinder head. mary throttle valve (not shown) is positioned supplies As is further preferred, the secondary fuel injector 202 air to the spacers 95 and 96. A secondary throttle valve comprises a nozzle having two jet openings to appropri- 204 is positioned in the spacer 96 and is operated in a ately serve the center valve seat 93 and the right-side staged sequence, like the throttle valve of the carburetor 25 valve seat 94. 55 of the previously described embodiment. As a result, The amount of fuel controlled by the fuel injector the flow for primary running under low speed low load 201 can be determined by the sensing of the position of conditions will be primarily through the primary intake the main throttle valve which, has been noted, is not passage 85 since the throttle valve 204 will be closed in shown. The secondary fuel injector 202 may have its this position. 30 amount of fuel controlled by either the position of the The fuel injectors 201, 202 are disposed inclined secondary throttle valve 204 or engine speed or a com- with respect to each of the associated first and second bination of them. As a result of this construction, good intake passages 85, 88 in order to meet the needs for fuel distribution and maximum performance can be supplying a charge to the left-side valve seat 87 and to achieved under all running conditions. the center valve seat 93 through the communicating 35 In the embodiments of the invention as thus far de- bore 1 48 fuel injector 201 , see Figure 9 and to supply a scribed, the primary and secondary intake passages 85 fuel/air charge to the center valve seat 93 and the right- and 88 and the interconnecting passageway 148 have side valve seat 94 from the fuel injector 202, see Figure all been formed in the cylinder head. Figure 10 shows 9. For that reason the second fuel injector 202 associ- another embodiment of the invention which achieves ated to the second intake passage 88 is disposed at a 40 some of the advantages of the previously described em- distance from the valve seats, specifically from the cent- bodiments but which has a simpler porting arrangement er and side valve seats 93, 94 which is shorter than the for the cylinder head. Again, the basic construction of distance of the first fuel injector 201 associated to the the cylinder head, valves, valve seats, etc is the same first intake passage 85. as the previously described embodiments and, for that It should be noted that the primary fuel injector 201 45 reason, those components which are same have been is disposed such that a portion of its spray jetted from identified by the same reference numerals and further the single central nozzle opening as indicated in Figure description of these common components is not be- 9 will be directed toward the communicating passage lieved to be necessary to enable those skilled in the art 148 and, accordingly, the center intake valve 101. This to understand the construction and operation of this em- will provide more equal flow distribution but does not ne- 50 bodiment. cessitate the supply of any significant mount of fuel to In this embodiment, the intake side of the cylinder the secondary intake passage portion 92. Therefore, head is formed with a single relatively large intake open- some minimal amount of stratification may be achieved, ing 251 that serves a single passage 252 that is divided if desired. Also as has been noted, the center intake into three portions 253, 254 and 255 at their outlet ends valve 101 has a greater lift so this will also facilitate some 55 which communicate with the valve seats 87, 93 and 94, fuel entry through the intake valve 101 from the primary respectively. The passages 252 are divided into primary fuel injector 201 via the communicating passage 148, and secondary supply sides by a bifurcated spacer as- when said central intake valve 101 is opened. Accord- sembly, indicated generally by the reference numeral

7 13 EP 0 499 268 B1 14

255 which has a primary runner 256 and a secondary in ratio is that some fuel from the injector 201 will flow runner 257. The primary and secondary runners 256 through the passageway 148 through the valve 102 so and 257 receive air from a common air source 258 in that the fuel injector 202 need not supply twice the which a primary throttle valve (not shown) is positioned. amount of the fuel as the injector 201 under this running A secondary valve 259 is positioned in the secondary 5 condition. passage 257 and is controlled in a staged sequence as With the embodiment of Figure 10, on the other with the secondary carburetor 55 of the embodiment of hand, the minimum ratio between the injectors 201 and Figures 1 through 8, and the secondary throttle valve 202 is equal at about 1 .5 to 1 .5 while at maximum run- 254 of the embodiment of Figure 9. A primary fuel injec- ning the ratio is 1 to 2 because of the more open com- tor 201 is disposed in the primary passage 256 and a 10 munication of the injectors 201 and 202 with each other secondary fuel injector 202 is positioned in the second- through the common passageway 252. ary passage 257. The primary and secondary fuel injec- It should be readily apparent from the foregoing de- tors 201 and 202, respectively, are controlled by a strat- scription that the described embodiments of the inven- egy similar to that described in conjunction with the em- tion provide a relatively simple yet effective porting ar- bodiment of Figure 9. 15 rangement for a three intake valve engine wherein the In the embodiment of Figure 10 the three portions performance will be maximized throughout the entire 253, 254, 255 of the common intake passage define engine speed and load ranges and there will be good wedge shaped wall projections 301 at both sides of the fuel distribution under all running conditions without ex- center valve seat 93 and the pair of fuel injectors 201 , cess fuel consumption. 202 is disposed such that both, to a certain extent supply 20 fuel to the center valve seat 93 and, as usually, also serve their associated side valve seat 87, 94. Accord- Claims ingly, it is preferred that the primary and secondary fuel injectors 201 , 202 being disposed inclined to a longitu- 1 . Multiple valve internal combustion engine compris- dinal center axis of the intake passage such that the lon- 25 ing a cylinder head (43) having at least three intake gitudinal center axis X-,, X2 of the fuel jets sprayed by valves (99,101,102) per cylinder and a staged the left and right side fuel injectors 201 , 202 are aligned induction system having at least two intake pas- with the tops of the associated wedge shaped wall pro- sages (85,88;253,254,255) serving the intake valve jections 301 at both sides of the center valve seat 93. seat openings of the cylinder head (43) and charge In the embodiments of Figures 9 and 10, the strat- 30 forming means (53,55;201 ,202) and an intercon- egy is, as previously noted, that the secondary fuel in- necting passage (148;252) connecting at least two jector 202 does not supply fuel until the mid-range per- of said intake passages (85,88), characterised in formance of the engine when the throttle valves 204 and that, said interconnecting passage (1 48;252) is dis- 259, respectively are open. However, once these throt- posed within the cylinder head (43) extending adja- tle valves are open then the proportion of fuel from the 35 cent to and towards a centre valve seat (93) allow- injectors 201 and 202 is controlled so that each injector ing the amount of the charge supplied to said centre supplies fuel. At the lower portion of the mid-range, valve seat (93) to be varied in response to the load when the injector 201 is supplying a lesser amount of conditions of the engine. fuel the ratio of fuel supplied between the injectors 201 and 202 is varied and a different ratio is employed with 40 2. Multiple valve internal combustion engine as the embodiment of Figure 9 than with the embodiment claimed in claim 1, characterised in that, a first of Figure 1 0 due to the fact that the embodiment of Fig- intake passage (85) is formed in said cylinder head ure 9 has limited communication between the passage- (43) and extends from a first intake port (86) to a ways 85 and 88 while the embodiment of Figure 1 0 has first valve seat (87) of the valve seats (87,93,94) of a common passageway 252. 45 said intake valves and a second passage (88) of Referring specifically to the embodiment of Figure Siamese type is formed in the cylinder head (43) and 9, when the engine is operating at the low end of the extends from a second intake port (89) in common high speed high load range, the ratio of fuel supplied to the second and third valve seats (93,94) of said between the injectors 201 and 202 is in the range of one valve seats (87,93,94), and said interconnecting to two in quantity. That is, when the injector 201 is sup- 50 passage (148;252) is provided for communicating plying a minimum of amount of fuel Q1 the amount of said first and second intake passages (85,88) fuel supplied by the injector 202 (Q2) equals twice the upstream of the centre valve seat (93). quantity Q1 = However, when running at maxi- q1 3. Multiple valve internal combustion engine as mum output and the injector 201 is supplying maximum 55 claimed in claim 2, characterised in that, the first intake passage (85) and that particular portion of fuel, the ratio is = 44- The reason for this difference the second intake passage (88) serving the third

8 15 EP 0 499 268 B1 16

valve seat (94) extend substantially in parallel to each have the same effective cross-sectional area, each other. and in that cross-sectional flow area of the second intake passage (88) is approximately equal to twice 4. Multiple valve internal combustion engine as the effective cross-section area of the first intake claimed in claims 2 or 3, characterised in that, a s passage (85). portion of the second intake passage (88) extending to the second, centre valve seat (93) is disposed at 10. Multiple valve internal combustion engine as an acute angle to the portion of the second intake claimed in at least one of the preceding claims 1 to passage (88) extending to the third, side intake 9, characterised in that, the fuel supplied by the valve seat (94). 10 first and second charge formers (53,55;201 ,202) is in the ratio of 1:2 at the low midrange end of the 5. Multiple valve internal combustion engine as range of engine performance. claimed in at least one of the preceding claims 2 to 4, characterised in that, said interconnecting pas- 11. Multiple valve internal combustion engine as sage (148) communicating the intake passages 15 claimed in at least one of the preceding claims 1 to (85,88) with each other comprises a passage, pref- 1 0, characterised in that, the ratio of fuel supplied erably a bore, extending at an acute angle to a first by the first and second charge formers (53,55; upstream portion of the second intake passage (88) 201,202) at maximum performance is approxi- and branching off of the first intake passage (85). mately equal to 1 .2 to 1 .8. 20 6. Multiple valve internal combustion engine as 12. Multiple valve internal combustion engine as claimed in claim 5, characterised in that, a shield- claimed in at least one of the preceding claims 1 to ing wedge shaped wall portion (300) defined by a 11, characterised in that, the first and second pair of passages (91,92) which define the down- charge formers comprise respective first and sec- stream end portion of the Siamese type second 25 ond fuel injectors (201,202). intake passage (88) is provided, said wall portion (300) projects within an area between the centre 13. Multiple valve internal combustion engine as valve seat (93) and a side valve seat (94) which are claimed in claim 1 2, characterised in that, the fuel supplied commonly from the Siamese type second injectors (201,202) are disposed inclined with intake passage (88) wherein a centre valve seat- 30 respect to each of the associated first and second oriented side of said projecting wall portion (300) is intake passages (85,88) with the second fuel injec- disposed substantially opposite to the downstream tor (202) associated to the second intake passage end portion of the interconnecting passage (148), (88) being disposed at a distance from the valve thereby shielding the related side valve seat (94) seats (87,93,94) shorter than the first fuel injector from that portion of an air-fuel charge fed through 35 (201 ) associated to the first intake passage (85). the interconnecting passage (148) to the centre valve seat (93). 14. Multiple valve internal combustion engine as claimed in claim 1 3, characterised in that, the sec- 7. Multiple valve internal combustion engine as ond fuel injector (202) being disposed such that a claimed in at least one of the preceding claims 1 to 40 longitudinal centre axis (X2) of the fuel jet sprayed 6, characterised in that, first and second charge into the second intake passage (88) by said second forming means (53,55;201 ,202) are provided for fuel injector (202) is aligned with the tip of a project- supplying a charge to the first and second intake ing wedge shaped wall portion (300) of the cylinder passages (85,88) respectively. head (43) which extends at an area between the 45 centre valve seat (93) and the side valve seat (94) 8. Multiple valve internal combustion engine as both being served by the Siamese type second claimed in claim 7, characterised in that, the first intake passage (88). and second charge formers (53,55;201 ,202) are operated in a stage sequence so that only the first 15. Multiple valve internal combustion engine as charge former (53,201) supplies fuel under low so claimed in claim 1 4, characterised in that, the first speed running conditions and both of the charge fuel injector (201) disposed remoter from the valve formers (53,55;201 ,202) supply fuel under high seats (87,93,94) and spraying into the first intake speed running conditions. passage (85) is disposed such to align a longitudi- nal centre axis (X-,) of its fuel jet sprayed into the 9. Multiple valve internal combustion engine as 55 first intake passage (85) to a side are a of the asso- claimed in at least one of the preceding claims 1 to ciated side valve seat (87). 8, characterised in that, the side and centre valve seats (87,93,94) of the intake valves (99,101,102) 16. Multiple valve internal combustion engine as

9 17 EP 0 499 268 B1 18

claimed in claim 1, characterised in that, said 3. Mehrventil-Verbrennungskraftmaschine nach Ans- staged induction system comprise a common intake pruch 2, dadurch gekennzeichnet, dal3 der erste passage (252) that is divided into three portions EinlaBkanal (85) und derjenige Abschnitt des zwei- (253,254,255) at their outlet end which communi- ten EinlaBkanals (88), der zu dem dritten Ventilsitz cate with the valve seats (87,93,94) of said intake s (94) fuhrt, sich im wesentlichen parallel zueinander valves, respectively, wherein wedge shaped wall erstrecken. projections (301) are formed at both sides of the centre valve seat (93) with a pair of fuel injectors 4. Mehrventil-Verbrennungskraftmaschine nach Ans- (201 ,202) being disposed to spray into primary and pruch 2 oder 3, dadurch gekennzeichnet, dal3 ein secondary passages (256,257) of an intake pipe 10 Abschnitt des zweiten EinlaBkanals (88), der zu defined by a spacer arrangement connected to the dem zweiten, mittleren Ventilsitz (93) fuhrt, unter upstream end of the common intake passage (252) einem spitzen Winkel zu dem Abschnitt des zweiten such that the position and configuration of the noz- EinlaBkanals (88), der sich zu dem dritten, seitli- zle openings of the fuel injectors (201,202) is chen EinlaBventilsitz (94) fuhrt, angeordnet ist. designed to align a longitudinal centre axis (X-,) of 15 the fuel jet sprayed by the left-side first fuel injector 5. Mehrventil-Verbrennungskraftmaschine nach min- (201) with the top of the associated left wedge destens einem der vorgenannten Anspruche 2 bis shaped wall projection (301) while a longitudinal 4, dadurch gekennzeichnet, dal3 der Verbin- centre axis (X2) of the fuel jet of the right-side sec- dungskanal (148), der die EinlaBkanale (85,88) mit- ond fuel injector (202) is aligned with the top of the 20 einander verbindet, einen Kanal, vorzugsweise associated right wedge-shaped wall projection eine Bohrung, aufweist, der sich unter einem spit- (301). zen Winkel zu einem ersten Stromauf-Abschnitt des zweiten EinlaBkanals (88) erstreckt und von dem ersten EinlaBkanal (85) abzweigt. Patentanspriiche 25 6. Mehrventil-Verbrennungskraftmaschine nach Ans- 1. Mehrventil-Verbrennungskraftmaschine mit einem pruch 5, dadurch gekennzeichnet, dal3 ein Zylinderkopf (43) mit zumindest drei EinlaBventilen abschirmender, keilformiger Wandabschnitt (300), (99,101,102) je Zylinder und einem gestuften vorgesehen ist, der durch ein Paar von Kanalen Zufuhrsystem mit mindestens zwei EinlaBkanalen 30 (91,92), die Stromab-Endabschnitte des siame- (85,88;253,254,255), die die EinlaBventilsitzoffnun- sischartigen zweiten EinlaBkanals (88) bilden, defi- gen des Zylinderkopfes (43) versorgen und niert ist, wobei der Wandabschnitt (300) in einem Ladungsbildungsvorrichtungen (53,55;201 ,202) Bereich zwischen dem Mittelventilsitz (93) und und einem Verbindungskanal (1 48;252), der zumin- einem Seitenventilsitz (94), die gemeinsam von dest zwei der EinlaBkanale (85,88) verbindet, 35 dem siamesischartigen zweiten EinlaBkanal (88) dadurch gekennzeichnet, dal3 der Verbindungs- versorgt werden, hervorsteht, wobei eine zum Mit- kanal (148;252) im Zylinderkopf (43) angeordnet telventilsitz hin orientierte Seite des vorspringen- ist, und sich in der Nahe und auf einen Mittelventil- den Wandabschnittes (300) im wesentlichen sitz (93) zu erstreckt zur Ermoglichung der Veran- gegenuber dem Stromab-Endabschnitt des Verbin- derung der dem Mittelventilsitz (93) zugefuhrten 40 dungskanals (148) angeordnet ist, zur Abschir- Ladungsmenge in Abhangigkeit der Lastzustande mung des betreffenden Seitenventilsitzes (94) von der Maschine. dem Luftkraftstoffladungsteil, der durch den Verbin- dungskanal (148) zu dem Mittelventilsitz (93) gefor- 2. Mehrventil-Verbrennungskraftmaschine nach Ans- dert wird. pruch 1 , dadurch gekennzeichnet, dal3 ein erster 45 EinlaBkanal (85) in dem Zylinderkopf (43) ausgebil- 7. Mehrventil-Verbrennungskraftmaschine nach min- det ist, der sich von einer ersten EinlaBoffnung (86) destens einem der vorgenannten Anspruche 1 bis zu einem ersten Ventilsitz (87) der Ventilsitze 6, dadurch gekennzeichnet, dal3 erste und zweite (87,93,94) der EinlaBventile erstreckt, und ein sia- Ladungsbildungsvorrichtungen (53,55;201 ,202) mesischartiger, zweiter EinlaBkanal (88) in dem so zur Zufuhrung einer Ladung zu den jeweiligen Zylinderkopf (43) ausgebildet ist, der sich von einer ersten und zweiten EinlaBkanalen (85,87) vorgese- zweiten EinlaBoffnung (89) zusammen zu den zwei- hen sind. ten und dritten Ventilsitzen (93,94) der Ventilsitze (87,93,94) erstreckt, und dal3 der Verbindungska- 8. Mehrventil-Verbrennungskraftmaschine nach Ans- nal (148;252) zur Verbindung der ersten und zwei- 55 pruch 7, dadurch gekennzeichnet, dal3 die ersten ten EinlaBkanale (85,88) stromauf des Mittelventil- und zweiten Ladungsbildungsvorrichtungen (53, sitzes (93) vorgesehen ist. 55;201,202) in einer Stufenfolge betatigt werden, so da!3 bei Niedriggeschwindigkeit-Fahrzustanden

10 19 EPEP0 0 499 26838 B1 20

lediglich die erste Ladungsbildungsvorrichtung kopfes (43) ausgerichtet ist, wobei der Wandab- (53,201) Kraftstoff zufuhrt und bei Hochgeschwin- schnitt sich in einem Bereich zwischen dem Mittel- digkeits-Fahrzustanden beide Ladungsbildungs- ventilsitz (93) und dem Seitenventilsitz (94), die vorrichtungen (53,55;201,202) Kraftstoff zufuhren. beide durch den siamesischartigen zweiten 5 EinlaBkanal (88) versorgt werden, erstreckt. 9. Mehrventil-Verbrennungskraftmaschine nach min- destens einem der vorgenannten Anspruche 1 bis 15. Mehrventil-Verbrennungskraftmaschine nach Ans- 8, dadurch gekennzeichnet, dal3 jeder Seiten- pruch 14, dadurch gekennzeichnet, daBdie erste bzw. Mittelventilsitz (87,93,94) der EinlaBventile Kraftstoffeinspritzvorrichtung (201), die weiter von (99,101,102) die gleiche effektive Querschnittsfla- 10 den Ventilsitzen (87,93,94) entfernt ist und in den che aufweist, und dal3 die stromungswirksame ersten EinlaBkanal (85) spritzt, so angeordnet ist, Querschnittsflache des zweiten EinlaBkanals (88) dal3 die Langsmittelachse (X-,) ihres in den ersten in etwa dem Zweifachen der effektiven Quer- EinlaBkanal (85) eingespritzten Kraftstoffstrahles schnittsflache des ersten EinlaBkanals (85) ent- zu einem Seitenbereich des zugehorigen Seiten- spricht. is ventilsitzes (87) ausgerichtet ist.

10. Mehrventil-Verbrennungskraftmaschine nach min- 16. Mehrventil-Verbrennungskraftmaschine nach Ans- destens einem der vorgenannten Anspruche 1 bis pruch 1, dadurch gekennzeichnet, dal3 das 9, dadurch gekennzeichnet, dal3 das Verhaltnis gestufte Zufuhrsystem einen gemeinsamen der Kraftstoff-Zufuhr durch die ersten und zweiten 20 EinlaBkanal (252) aufweist, der an seinem AuslaB- Ladungsbildungsvorrichtungen (53,55;201 ,202) ende, das mit den Ventilsitzen (87,93,94) der Ein- am unteren Ende des mittleren Leistungsbereichs laBventile kommuniziert, entsprechend in drei der Maschine 1:2 betragt. Abschnitte (253,254,255) geteilt ist, wobei keilfor- mige Wandvorsprunge (301) an beiden Seiten des 11. Mehrventil-Verbrennungskraftmaschine nach min- 25 Mittelventilsitzes (93) gebildet sind, mit einem Paar destens einem der vorgenannten Anspruche 1 bis von Kraftstoffeinspritzvorrichtungen (201 ,202), die 10, dadurch gekennzeichnet, dal3 das Kraftstoff- zum Spritzen in den ersten und zweiten EinlaBkanal zufuhrverhaltnis der ersten und zweiten Ladungs- (256,257) eines EinlaBrohres angeordnet sind, das bildungsvorrichtung (53,55;201 ,202) bei maximaler durch eine Abstandsvorrichtung mit dem stromauf- Leistung in etwa 1 ,2 bis 1 ,8 betragt. 30 wartigen Ende des gemeinsamen EinlaBkanals (252) verbunden ist, derart, dal3 die Lage und 12. Mehrventil-Verbrennungskraftmaschine nach min- Anordnung der Dusenoffnungen der Kraftstoffein- destens einem der vorgenannten Anspruche 1 bis spritzvorrichtungen (201,202) so gestaltet ist, dal3 11, dadurch gekennzeichnet, dal3 die erste und die Langsmittelachse (X-,) eines durch eine links- zweite Ladungsbildungsvorrichtung entsprechend 35 seitige erste Kraftstoffeinspritzvorrichtung (201) eine erste und eine zweite Kraftstoffeinspritzvor- gespritzten Kraftstoffstrahls auf die Kante des richtung (201,202) aufweisen. zugehorigen linken keilformigen Wandvorsprunges (301) ausgerichtet ist, wahrend die Langsmittel- 13. Mehrventil-Verbrennungskraftmaschine nach Ans- achse (X2) eines Kraftstoffstrahls einer rechtsseiti- pruch 12, dadurch gekennzeichnet, dal3 die Kraft- 40 gen zweiten Kraftstoffeinspritzvorrichtung (202) auf stoffeinspritzvorrichtungen (201,202) relativ zu die Kante des zugehorigen rechten keilformigen jedem der zugehorigen ersten und zweiten EinlaB- Wandvorsprunges (301) ausgerichtet ist. kanale (85,88) geneigt angeordnet sind, wobei der die zweite Kraftstoffeinspritzvorrichtung (202), die dem zweiten EinlaBkanal (88) zugeordnet ist, in 45 Revendications kurzerer Entfernung zu den Ventilsitzen (87,93,94) angeordnet ist, als die erste Kraftstoffeinspritzvor- 1 . Moteur a combustion interne a multiples soupapes richtung (201), die dem ersten EinlaBkanal (85) comprenant une culasse (43) comportant au moins zugeordnet ist. trois soupapes d'admission (99, 101,1 02) par cylin- 50 dre et un systeme d'admission etage comportant au 14. Mehrventil-Verbrennungskraftmaschine nach Ans- moins deux passages d'admission (85, 88; 253, pruch 13, dadurch gekennzeichnet, dal3 die 254, 255) desservant des ouvertures de sieges de zweite Kraftstoffeinspritzvorrichtung (202) so ange- soupapes d'admission de la culasse (43) et des ordnet ist, dal3 eine Langsmittelachse (X2) eines moyens de formation de dose de carburation (53, durch die zweite Kraftstoffeinspritzvorrichtung 55 55; 201 , 202) et un passage d'interconnexion (1 48; (202) in den EinlaBkanal (88) eingespritzten Kraft- 252) reliant au moins deux des dits passages stoffstrahls zu der Kante eines hervorstehenden d'admission (85, 88), keilformigen Wandabschnittes (300) des Zylinder- caracterise en ce que

11 21 EP 0 499 268 B1 22

ledit passage d'interconnexion (148; 252) est ame- comme revendique dans la revendication 5, nage a I'interieur de la culasse (43) s'etendant de caracterise en ce que maniere adjacente a et vers un siege de soupape une partie de paroi de protection de forme angulaire central (93) permettant a la quantite de dose de - (300) definie par une paire de passages (91 , 92) qui buration alimentant ledit siege de soupape central 5 definissent la partie d'extremite aval du second pas- (93) d'etre modifiee en fonction des conditions de sage d'admission de type jumele (88) est amena- charge du moteur. gee, ladite partie de paroi (300) est en saillie a I'inte- rieur d'une zone comprise entre le siege de sou- 2. Moteur a combustion interne a multiples soupapes pape central (93) et un siege de soupape lateral comme revendique dans la revendication 1 , 10 (94) qui sont alimentes en commun par le second caracterise en ce que passage d'admission de type jumele (88) dans un premier passage d'admission (85) est forme lequel un cote oriente vers le siege de soupape cen- dans ladite culasse (43) et s'etend depuis un pre- tral de ladite partie de paroi en saillie (300) est ame- mier orifice d'admission (86) jusqu'a un premier nagee de maniere essentiellement opposee a la siege de soupape (87) des sieges de soupape (87, is partie d'extremite aval du passage d'interconnexion 93, 94) des dites soupapes d'admission et un (148), protegeant ainsi le siege de soupape (94) en second passage (88) de type jumele est forme dans rapport de cette partie d'une dose de carburation la culasse (43) et s'etend depuis un second orifice air / carburant alimentant le siege de soupape cen- d'admission (89) en commun jusqu'aux second et tral (93) par I'intermediaire du passage d'intercon- troisieme sieges de soupape (93, 94) des dits sie- 20 nexion(148). ges de soupape (87, 93, 94), et ledit passage d'interconnexion (148; 252) est amenage pourfaire 7. Moteur a combustion interne a multiples soupapes communiquer lesdits premier et second passages comme revendique dans au moins une des reven- d'admission (85, 88) en amont du siege de soupape dications precedentes 1 a 6, central (93). 25 caracterise en ce que les premier et second moyens de formation de dose 3. Moteur a combustion interne a multiples soupapes de carburation (53, 55; 201, 202) sont destines a comme revendique dans la revendication 2, fournir une dose de carburation respectivement aux caracterise en ce que premier et second passages d'admission (85, 88). le premier passage d'admission (85) et cette partie 30 particuliere du second passage d'admission (88) 8. Moteur a combustion interne a multiples soupapes desservant le troisieme siege de soupape (94) comme revendique dans la revendication 7, s'etendent essentiellement parallelement I'un par caracterise en ce que rapport a I'autre. les premier et second moyens de formation de dose 35 de carburation (53, 55; 201, 202) fonctionnent en 4. Moteur a combustion interne a multiples soupapes sequence etagee de telle sorte que seul le premier comme revendique dans les revendications 2 ou 3, moyen de formation de dose de carburation (53, caracterise en ce que 201) fournit une alimentation en carburant en con- une partie du second passage d'admission (88) dition de fonctionnement a bas regime et les deux s'etendant jusqu'au second siege de soupape cen- 40 moyens de formation de dose de carburation (53, tral (93) est amenagee a angle aigu jusqu'a la partie 55; 201, 202) fournissent une alimentation en car- du second passage d'admission (88) s'etendant burant en condition de fonctionnement a haut jusqu'au troisieme siege de soupape d'admission regime. lateral (94). 45 9. Moteur a combustion interne a multiples soupapes 5. Moteur a combustion interne a multiples soupapes comme revendique dans au moins une des reven- comme revendique dans au moins une des reven- dications precedentes 1 a 8, dications precedentes 2 a 4, caracterise en ce que caracterise en ce que les sieges de soupape central et lateraux (87, 93, ledit passage d'interconnexion (148) faisant com- 50 94) des soupapes d'admission (99, 101, 102) ont muniquer I'un avec I'autre les passages d'admis- chacun effectivement la meme surface en coupe sion (85, 88) comprend un passage, de preference transversale, et en ce que la surface de debit du un alesage, s'etendant a angle aigu jusqu'a une second passage d'admission (88) vue en coupe premiere partie amont du second passage d'admis- transversale est egale a environ deuxfois la surface sion (88) et en derivation du premier passage 55 effective en coupe transversale du premier passage d'admission (85). d'admission (85).

6. Moteur a combustion interne a multiples soupapes 10. Moteur a combustion interne a multiples soupapes

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comme revendique dans au moins une des reven- caracterise en ce que dications precedentes 1 a 9, le premier injecteur de carburant (201) dispose de caracterise en ce que maniere plus eloignee des sieges de soupape (87, I'alimentation en carburant par les premier et 93, 94) et pulverisant a I'interieur du premier pas- second moyens de formation de dose de carbura- s sage d'admission (85) est dispose de telle sorte qu'il tion (53, 55; 201 , 202) est dans un rapport de 1 : 2 est dans I'alignement d'un axe central longitudinal a I'extremite basse de la plage moyenne de la plage (X1) de son jet de carburant pulverise a I'interieur de performances du moteur. du premier passage d'admission (85) sur un cote ou se trouve I'un des sieges de soupape associes 11. Moteur a combustion interne a multiples soupapes 10 (87). comme revendique dans au moins une des reven- dications precedentes 1 a 10, 16. Moteur a combustion interne a multiples soupapes caracterise en ce que comme revendique dans la revendication 1 , le rapport de carburant fourni par les premier et caracterise en ce que second moyens de formation de dose de carbura- 15 ledit systeme d'admission etagee comprend un tion (53, 55; 201, 202) a un maximum de perfor- passage d'admission commun (252) qui est divise mance est approximativement compris entre 1 ,2 et en trois parties (252, 253, 254) en son extremite de 1,8. sortie qui communique respectivement avec les sieges de soupape (87, 93, 94) des dites soupapes 12. Moteur a combustion interne a multiples soupapes 20 d'admission, dans lequel les saillies de paroi de comme revendique dans au moins une des reven- forme angulaire (301 ) sont formees des deux cotes dications precedentes 1 a 11, du siege de soupape central (93) avec une paire caracterise en ce que d'injecteurs de carburant (201 , 202) qui sont dispo- les premier et second moyens de formation de dose ses pour effectuer une pulverisation a I'interieur des de carburation comprennent respectivement un 25 premier et second passages (256, 257) d'une tubu- premier et un second injecteur de carburant (201, lure d'admission definie par un dispositif de piece 202). d'epaisseur reliee a I'extremite amont du passage d'admission commun (252) de telle sorte que la 13. Moteur a combustion interne a multiples soupapes position et la configuration des buses d'injection des comme revendique dans la revendication 12, 30 injecteurs de carburant (201, 202) leur permettent caracterise en ce que d'aligner un axe central longitudinal (X1) du jet de les injecteursde carburant (201 , 202) sont disposes carburant pulverise par le premier injecteur de car- de maniere inclinee par rapport a chacun des pre- burant situe du cote gauche (201) avec I'extremite mier et second passages d'admission associes (85, de la saillie de paroi de forme angulaire associee 88) le second injecteur de carburant (202) associe 35 gauche (301) tandis qu'un axe central longitudinal au second passage d'admission (88) etant dispose (X2) du jet de carburant du second injecteur de car- a une plus faible distance des sieges de soupape burant situe du cote droit (202) est aligne avec (87, 93, 94) que le premier injecteur de carburant I'extremite de la saillie de paroi de forme angulaire (201) associe au premier passage d'admission associee droite (301). (85). 40

14. Moteur a combustion interne a multiples soupapes comme revendique dans la revendication 13, caracterise en ce que le second injecteur de carburant (202) etant dis- 45 pose de telle sorte qu'un axe central longitudinal (X2) du jet de carburant pulverise a I'interieur du second passage d'admission (88) par ledit second injecteur de carburant (202) est dans I'alignement de I'extremite d'une partie de paroi de forme angu- so laire saillante (300) de la culasse (43) qui s'etend sur une zone situee entre le siege de soupape cen- tral (93) et le siege de soupape lateral (94) tous deux etant desservis par le second passage d'admission de type jumele (88). 55

15. Moteur a combustion interne a multiples soupapes comme revendique dans la revendication 14,

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Figure 4

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Figure 5

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Figure 7

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Figure 8

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