Europäisches Patentamt *EP001323902A2* (19) European Patent Office Office européen des brevets (11) EP 1 323 902 A2 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.7: F01L 1/34, F02D 13/00 02.07.2003 Bulletin 2003/27 (21) Application number: 02029073.0 (22) Date of filing: 30.12.2002 (84) Designated Contracting States: (72) Inventor: Shimizu, Hirokazu AT BE BG CH CY CZ DE DK EE ES FI FR GB GR Atsugi-shi, Kanagawa (JP) IE IT LI LU MC NL PT SE SI SK TR Designated Extension States: (74) Representative: Grünecker, Kinkeldey, AL LT LV MK RO Stockmair & Schwanhäusser Anwaltssozietät Maximilianstrasse 58 (30) Priority: 28.12.2001 JP 2001399619 80538 München (DE) (71) Applicant: Hitachi Unisia Automotive Ltd. Kanagawa (JP) (54) Ignition timing control apparatus for internal combustion engine and method thereof (57) A controlled variable and a target in each of a ing to the target and also to calculate actual opening variable valve event and lift control apparatus and a var- timing of the intake valve corresponding to the controlled iable valve timing control apparatus are input, to calcu- variable, to correct ignition timing based on a deviation late target opening timing of an intake valve correspond- between the target opening timing and the actual open- ing timing. EP 1 323 902 A2 Printed by Jouve, 75001 PARIS (FR) 1 EP 1 323 902 A2 2 Description event and lift mechanism, there is a problem in that since the deviation between the actual valve timing and the Field of the Invention target valve timing cannot be detected, the ignition tim- ing cannot be appropriately corrected. [0001] The present invention relates to an ignition tim- 5 ing control apparatus and an ignition timing control SUMMARY OF THE INVENTION method in an internal combustion engine, in which valve timing and a valve lift of an intake valve are variably con- [0010] It is therefore an object of the present invention trolled. to enable to appropriately correct ignition timing even in 10 a transition period of valve timing and a valve lift of an Related Art of the Invention intake valve, in an engine provided with a variable valve timing mechanism and a variable valve event and lift [0002] Heretofore, in an internal combustion engine mechanism. provided with a variable valve mechanism, there has [0011] In order to accomplish the above-mentioned been known a constitution wherein ignition timing is cor- 15 object, according to the present invention, a controlled rected according to a variation in valve timing of an in- variable and a target in each of variable valve event and take valve. lift control apparatus and variable valve timing control [0003] Japanese Unexamined Patent Publication No. apparatus are input to calculate target opening timing of 2001-221105 discloses a constitution in which valve an intake valve corresponding to the target, and also ac- overlap is calculated based on target opening timing of 20 tual opening timing of the intake valve corresponding to an intake valve and target closing timing of an exhaust the controlled variable, to correct ignition timing based valve, and a cylinder residual exhaust gas amount is es- on a deviation between the target opening timing and timated based on the valve overlap, to correct ignition the actual opening timing. timing according to the cylinder residual exhaust gas [0012] The other objects and features of the invention amount. 25 will become understood from the following description [0004] Further, Japanese Unexamined Patent Publi- with reference to the accompanying drawings. cation No. 9-209895 discloses a constitution in which basic ignition timing is corrected according to a deviation BRIEF DESCRIPTION OF THE DRAWINGS between actual valve timing and target valve timing of an intake valve. 30 [0013] [0005] However, in the constitution disclosed in Jap- anese Unexamined Patent Publication No. Fig. 1 is a diagram of a system structure of an in- 2001-221105, there is a problem in that a correction that ternal combustion engine in an embodiment. does not correspond to an actual valve overlap amount Fig. 2 is a cross section view showing a variable is performed on ignition timing, during a transition period 35 valve event and lift mechanism (A-A cross section wherein a deviation is caused between actual valve tim- of Fig. 3) in the embodiment. ing and target valve timing. Fig. 3 is a side elevation view of the variable valve [0006] On the other hand, in the constitution disclosed event and lift mechanism. in Japanese Unexamined Patent Publication No. Fig. 4 is a top plan view of the variable valve event 9-209895, ignition timing can be appropriately corrected 40 and lift mechanism. corresponding to a transition state of valve timing. Fig. 5 is a perspective view showing an eccentric [0007] However, the constitution disclosed in Japa- cam for use in the variable valve event and lift mech- nese Unexamined Patent Publication No. 9-209895 is anism. to be applied to an engine provided with only a variable Fig. 6 is a cross section view showing a low lift con- valve timing mechanism, in which the actual valve timing 45 dition by the variable valve event and lift mechanism is detected by detecting rotation phases of a crankshaft (B-B cross section view of Fig. 3). and a camshaft. Fig. 7 is a cross section view showing a high lift con- [0008] However, in the case where there is provided, dition by the variable valve event and lift mechanism together with a variable valve timing mechanism, a var- (B-B cross section view of Fig. 3). iable valve event and lift mechanism that varies contin- 50 Fig. 8 is a characteristic diagram showing a corre- uously a valve lift with a valve event of an intake valve, lation between an angle range of a cam surface, even if the rotation phases of the crankshaft and cam- and a valve lift in the variable valve event and lift shaft are the same, valve timing of the intake valve is mechanism. varied depending on a difference of valve lift. Fig. 9 is a characteristic diagram showing valve tim- [0009] Consequently, according to such a method as 55 ing and the valve lift of the variable valve event and disclosed in Japanese Unexamined Patent Publication lift mechanism. No. 9-209895, in the case of an engine provided with a Fig. 10 is a perspective view showing a rotational variable valve timing mechanism and a variable valve driving mechanism of a control shaft in the variable 2 3 EP 1 323 902 A2 4 valve event and lift mechanism. 132. Fig. 11 is a longitudinal cross section view of a var- [0026] Each ignition plug 132 is provided with an ig- iable valve timing mechanism in the embodiment. nition coil 133 incorporating therein a power transistor. Fig. 12 is a control block diagram showing an igni- Engine control unit 114 switching controls the power tion timing control in the embodiment. 5 transistor to control ignition timing (ignition advance val- ue). DESCRIPTION OF THE PREFERRED EMBODIMENT [0027] Ignition plug 132 and ignition coil 133 consti- tute an ignition apparatus. [0014] Fig. 1 is a structural diagram of an internal [0028] Fig. 2 to Fig. 4 show in detail the structure of combustion engine for vehicle in an embodiment. 10 variable valve event and lift mechanism 112. [0015] In Fig. 1, in an intake passage 102 of an inter- [0029] Variable valve event and lift mechanism 112 nal combustion engine 101, an electronically controlled shown in Fig. 2 to Fig. 4 includes a pair of intake valves throttle 104 is disposed for driving a throttle valve 103b 105, 105, a hollow camshaft (drive shaft) 13 rotatably to open and close by a throttle motor 103a. supported by a cam bearing 14 of a cylinder head 11, [0016] Air is sucked into a combustion chamber 106 15 two eccentric cams (drive cams) 15, 15 as rotating cams via electronically controlled throttle 104 and an intake axially supported by camshaft 13, a control shaft 16 ro- valve 105. tatably supported by cam bearing 14 and arranged at [0017] A combusted exhaust gas is discharged from an upper position of camshaft 13, a pair of rocker arms combustion chamber 106 via an exhaust valve 107, pu- 18, 18 swingingly supported by control shaft 16 through rified by a front catalyst 108 and a rear catalyst 109, and 20 a control cam 17, and a pair of independent swing cams then emitted into the atmosphere. 20, 20 disposed to upper end portions of intake valves [0018] Exhaust valve 107 is driven to open and close 105, 105 through valve lifters 19, 19, respectively. by a cam 111 axially supported by an exhaust side cam- [0030] Eccentric cams 15, 15 are connected with shaft 110, at fixed valve lift, valve event and valve timing. rocker arms 18, 18 by link arms 25, 25, respectively. [0019] A valve lift and a valve event of intake valve 25 Rocker arms 18,18 are connected with swing cams 20, 105 are varied continuously by a variable valve event 20 by link members 26, 26. and lift mechanism 112, and valve timing thereof is var- [0031] Rocker arms 18, 18, link arms 25, 25, and link ied continuously by a variable valve timing mechanism members 26, 26 constitute a transmission mechanism. 113. [0032] Each eccentric cam 15, as shown in Fig. 5, is [0020] An engine control unit 114 incorporating there- 30 formed in a substantially ring shape and includes a cam in a microcomputer, controls electronically controlled body 15a of small diameter, a flange portion 15b inte- throttle 104, variable valve event and lift mechanism 112 grally formed on an outer surface of cam body 15a.