Europaisches Patentamt A European Patent Office Office europeen des brevets (Ti) Publication number: 0 324 553 S1 EUROPEAN PATENT SPECIFICATION @ Date of publication of patent specification : S) mtci.6: F16D 25/14 03.07.91 Bulletin 91/27 @ Application number: 89300118.0 Date of filing : 06.01.89 Clutch actuator system for automatic/semi-automatic mechanical transmission system. @) Priority: 13.01.88 GB 8800741 Proprietor : EATON CORPORATION Eaton Center, 1111 Superior Avenue Cleveland Ohio 44114 (US) © Date of publication of application : 19.07.89 Bulletin 89/29 Inventor: Cottam, Michael John 54 Glen Park Drive Hesketh Bank Lanes PR4 @) Publication of the grant of the patent : Near Preston 6TA (GB) 03.07.91 Bulletin 91/27 Inventor : Nellums, Richard Alexander 46 Long Copse Chorley Lanes. PR7 1TH (GB) @) Designated Contracting States : DE ES FR GB IT SE Representative : Douglas, John Andrew Eaton House Staines Road Hounslow Middlesex TW4 5DX (GB) References cited : EP-A- 0 158 004 EP-A- 0 231 465 EP-A- 0 239 471 DE-A- 3 010 503 DE-A- 3 246 362 0Q CO in m CO Note : Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Q_ Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been LU filed until the opposition fee has been paid (Art. 99(1) European patent convention). Jouve, 18, rue Saint-Denis, 75001 PARIS 1 EP 0 324 553 B1 Description invention never allows manual override of an automa- tic control of a clutch (by the central control which BACKGROUND OF THE INVENTION actuates a transmission). Field of the Invention 5 BRIEF DESCRIPTION OF THE DRAWINGS The present invention relates to a clutch actuator Figure 1 is a schematic illustration of a prior art se- system for use in automatic/semi-automatic mechani- mi-automatic mechanical transmission system. cal transmission systems (AMT/SAMT). In particular, Figure 2 is a schematic illustration of the clutch the present invention relates to a clutch actuation sys- 10 actuation system of the present invention. tem for AMT/SAMT use which utilizes the standard Figure 1 illustrates an AMT/SAMT system 10 of components of the clutch actuation system normally the "three pedal" type having a throttle pedal 24, a provided (usually by the vehicle assembler) for man- brake pedal (not illustrated) and a clutch pedal 3. It is ually operated master clutches. understood that the present invention is also applic- 15 able to "two-pedal" type system having only a throttle The Prior Art pedal and a brake pedal. Transmission systems of the type illustrated in Figure 1 may be appreciated in gre- Automatic mechanical transmission systems ater detail by reference to above-mentioned US (AMTs) and semi-automatic mechanical transmission Patent No. 4,648 290. systems (SAMTs) are known in the prior art as may be 20 Referring to Figure 1, the position of a driver- seen by reference to United States Patent Nos. operated throttle 24 is sensed at sensor 22 and fed to 4,361,060 ; 4,527,447 and 4,648,290, the disclosures a central processing unit 38, which also receives of which are hereby incorporated by reference. The inputs relative to engine speed from sensor 28 and/or prior art systems utilized an engagable and disengag- transmission input shaft speed from sensor 32, from able master friction clutch drivingly interposed the ve- 25 transmission output shaft speed from sensor 36, and hicle engine and the transmission gearing. Control from positive or negative actuations of the driver's means, usually microprocessor based, are utilized to gear shift lever, or "joy stick" 1. It is understood that provide command output signals to actuators to auto- engine speed is an indication of transmission input matically operate the clutch and transmission based shaft speed, and visa versa, especially if clutch 16 is upon sensed inputs and predetermined logic rules. 30 nonslippingly engaged. The systems could be "two-pedal" systems with only Control logic circuits, sensors and actuators for automatic clutch actuation or "three-pedal" systems the transmission system 1 0 as disclosed in Figure 1 having manual as well as automatic clutch actuation may be as disclosed in U.S. Patent No. 4,361 ,060, the for start-from-stop and/or other modes of operation. disclosure of which is hereby incorporated by refer- In the prior art systems, the AMT/SAMT systems 35 ence. Specifically, central processing unit 38 receives utilized fully integrated clutch actuation systems inputs, processes same in accordance with predeter- which utilized little or none of the actuation/assist mined logic rules and provides command output sig- mechanisms normally provided by the vehicle man- nals to pneumatic and/or electrical actuators for ufacturers for manual transmission systems. This control of an exhaust brake 17 and/or an input shaft may require the vehicle manufacturer to utilize and/or 40 brake 1 8 for rapid upshifts, and automatic fuel control design-in components with which he is not familiar. 26 to "blip" the supply of fuel to the engine 14 to EP-A-0 231 465 discloses the pre-characterizing achieve rapid synchronous rotation preparatory to a part of Claim 1 . downshift, clutch control via operator 30, and ratio In accordance with the present invention, the shifting via transmission operator 34. The central pro- drawbacks of the prior art have been minimized by the 45 cessing unit also sends command output signals to provision of an AMT/SAMT clutch actuator system the display 2 to be described in greater detail below. utilizing many of the master clutch control compo- The semi-automatic transmission system 10 nents typically provided, and engineered into, vehi- additionally comprises a usual foot operated manual cles having a manual transmission system. clutch control 3 intended for use only for startfrom rest The above is accomplished by utilizing the stan- 50 and/or low speed creeping maneuvering situations. dard clutch actuator, reservoir, assist mechanism The semi-automatic mechanical transmission system and/or standard master-cylinder and inserting an 1 0 also includes sources of electric and/or pneumatic additional automatically controlled actuator in the power (not illustrated). control circuit. Figure 2 illustrates the clutch control system 100 DE-A-3 246 362 shows a manual controlled 55 of the present invention as utilized with the SAMT sys- clutch with manual override of an automatic actuation tem 10 illustrated in Figure 1. responsive to an engine braking sensing ; it discloses The clutch actuation system 100 makes use of no automatic transmission. In contrast, the present the existing standard manual clutch control compo- EP 0 324 553 B1 nents predesigned into a particular vehicle by the ve- said inlet (120), wherein said automatic clutch hicle builder. This minimizes component and instal- actuator operator (30) is biased normally to provide lation engineering costs. The standard manual clutch substantially unobstructed fluid communication bet- control system includes an hydraulic reservoir 102 ween said inlet (120) and said outlet (122) of the supplying hydraulic fluid to a master cylinder 104 5 operator (30), but responsive to command signals operated by the clutch pedal 3. The master cylinder from an automatic or semi-automatic transmission output 106 is normally connected to the input 108 of control (38) to overcome the bias of the operator (30) a clutch actuator 1 10 by fluid lines 1 12, 1 14 and 116. and thereby also to pressurize said fluid at said outlet The clutch actuator typically includes a servo-assist (122) and to block said inlet (120) ; with consequent mechanism 118 to minimize force required at the 10 release actuation of said clutch whether or not said pedal 3, and use of the existing assist mechanism master cylinder (104) is manually operated. minimizes the size of required AMT/SAMT clutch actuation devices. All of the existing components are, of course, Anspruche available to and designed into existing vehicles mak- 15 ing the use of an AMT/SAMT easier and less costly to 1. Korperlich (manuell) zu betatigendes Kup- a vehicle manufacturer. plungsbetatigungssystem (100) der Bauart mit einem To provide automatic clutch operation, an auto- Fluidvorratsbehalter (102), der stromungsmaBig mit matic clutch operator 30 is interposed between the einem Kupplungsstellantrieb (111) verbunden ist, der standard master cylinder 104 and the standard clutch 20 dazu dient, ein Drucklager (16) auszuriicken ; mit ei- actuator 110. nem korperlich (manuell) zu betatigenden Kupplungs- The actuator 30 is controlled directly or indirectly hauptzylinder (104) der stromungsma&ig zwischen by command output signals from CPU 38 and dem Vorratsbeha Iter (1 02) und dem Stellantrieb (110) includes an inlet 120 connected to the reservoir 102 angeordnet ist, dadurch gekennzeichnet, daft zum by conduit 112 and an outlet 122 connected to the 25 Zweck einer automatischen oder halbautomatischen standard clutch actuator 110 by conduit 116. As is Kupplungsbetatigung eine Betatigungseinrichtung shown, upon actuation of either the master cylinder (30) in Serie zwischen dem Kupplungshauptzylinder 1 04 or the automatic actuator 30, fluid connections to (104) und dem Kupplungsstellantrieb (110) eingefugt upstream hydraulic connections are closed. ist, daft die Betatigungseinrichtung (30) einen stro- in the illustrated three pedal system, the clutch 30 mungsmaBig an den AuslaB (106) des Kupplungs- may be operated by either the manual pedal 3 or the hauptzylinders angeschlossenen EinlaB (120) sowie CPU 38. In a two-pedal system not embodying the einen stromungsmaBig an den EinlaB (108) des Kup- invention, the reservoir 102 is connected directly to plungsstellantriebes (110) angeschlossenen AuslaB conduit 112, and the pedal 3 and master cylinder 104 (122) aufweist, da& der Kupplungshauptzylinder may be eliminated from system 100.