Dana Corporation

Transmission Technologies Corporation

Transmission Tsp, S.a. De C.v.

Tranmissiones Tsp, S.a. De C.v.

Kurt R Baer

George A Willford

John M Loeffler

Dennis D Schwaiger

James A Wheeler

Anand C Patel

Timothy R Zuehlke

James L Holman

Kenneth B Yant

Liu Ning

An apparatus and method for performing a kiss point determining algorithm which is responsive to the approach rate of the release bearing of a clutch for performing the algorithm only under reliable operating conditions. The apparatus includes an electronic controller which sets an approach rate for engaging the clutch in response to the amount of depression of the accelerator pedal of the vehicle by the operator. The amount of engine torque or other engine operating condition is measured and compared against a predetermined magnitude which is indicative of the onset of engagement of the clutch. When an increase of a predetermined magnitude is detected, the accelerator pedal position is compared against a predetermined value. If the accelerator pedal is depressed more than the predetermined value, the kiss point is re-defined as the current location of the release bearing. If the accelerator pedal is not depressed more than the predetermined value, the kiss point is not re-defined.

Method and apparatus for operating a clutch in an automated mechanical transmission

An apparatus and method for controlling the rate of engagement of a clutch in response to an indication provided by the driver, such as the depression of an accelerator pedal of the vehicle. The apparatus includes an electronic controller which initially determines a start rate as the minimum duty cycle which is required to modulate an engage valve in order to cause movement of a release bearing of the clutch in the engagement direction. Following the receipt of a signal from the operator of the vehicle to initiate the engagement of the clutch, the electronic controller calculates an initial transition rate of movement of the release bearing from a disengaged position to a transition point. The transition rate is determined as a function of the start rate and a position error signal. The position error signal can be calculated as the difference between the actual position of the release bearing and the transition point. When the release bearing reaches the transition point, the electronic controller re-sets the engagement rate to an approach rate for movement of the release bearing from the transition point to a kiss point. The approach rate is determined as a function of the start rate and an accelerator pedal position signal.

An electronic controller for use in a partially or fully automatic vehicle transmission. The transmission includes an automatic shifting mechanism for partially or fully automating the shifting thereof to select and engage gear ratios. The automatic shifting decisions are made by an electronic control circuit including an electronic controller which receives electrical signals representative of the rotational speeds of the input and output shafts of the transmission. An algorithm is performed by the electronic controller to identify the structure of the underlying transmission and adopt an appropriate shifting strategy based upon the rotational speeds of the input and output shafts of the transmission. Initially, the electronic controller determines if the transmission is, in fact, engaged in a gear ratio. Once it has been determined that the transmission is engaged in a gear ratio, the electronic controller determines what the specific magnitude of that gear ratio is. Next, the electronic controller identifies a particular structure for the transmission based upon a plurality of sensed gear ratios. The electronic controller may employ principles of fuzzy logic to assist in identifying the underlying transmission structure. Lastly, the electronic controller adopts a shifting strategy which is appropriate for the identified transmission structure for use in performing subsequent automatic shifting functions.

Electronic controller for identifying and operating an automated manual

A clutch actuator includes an outer cylinder housing having a plurality of ramps formed on an inner cylindrical surface thereof. Each of the ramps has a radially inwardly facing surface which includes a forwardly facing tapered surface and a rearwardly facing tapered surface. A hollow cylindrical piston is disposed concentrically within the outer cylinder housing and has a plurality of axially extending protrusions formed thereon. Preferably, the number of such protrusions is equal to the number of the ramps formed on the outer cylinder housing, and the protrusions are circumferentially interleaved within the ramps formed on the outer cylinder housing. Each of the protrusions has a radially outwardly facing surface which includes a forwardly facing tapered surface and a circumferentially extending groove. An inner cylinder housing is disposed concentrically within the piston. The outer and inner cylinder housings are fixed in position and define an annular chamber within which the piston can reciprocate axially. The piston is connected to a release sleeve of a clutch by means of a snap ring which is disposed within the grooves formed in the protrusions of the piston. Thus, the piston is connected to the release sleeve for axial movement therewith to operate the clutch. To disconnect the clutch actuator from the clutch, the piston is moved axially to a point where the snap ring engages the rearwardly facing tapered surfaces provided on the ramps of the outer cylinder housing. The rearwardly facing tapered surfaces provided on the ramps move the snap ring out of the grooves formed in the protrusions, thereby disconnecting the piston from the release sleeve.

Clutch actuator

An interlock assembly for a vehicle transmission prevents more than one of a plurality of shift rails from being simultaneously moved axially out of a central neutral position to a gear engaging position. The interlock assembly includes an interlock plate having four semi-circular cut-outs (one for each of the shift rails) and two relative large interior openings. The interlock assembly further includes a backing plate which is somewhat smaller than the interlock plate and has two relatively small interior openings. A pair of threaded fasteners extend through the small openings of the backing plate and through respective spacer bushings disposed in the large interior openings of the interlock plate into threaded engagement with the housing of the hydraulic actuator. The spacer bushings prevent the interlock plate from being frictionally engaged between the backing plate and the housing of the hydraulic actuator. As a result, the interlock plate is loosely supported on the threaded fasteners and can slide freely in any direction relative thereto. Each of the four cut-outs of the interlock plate is formed having opposed tapered edges which cooperate with tapered grooves formed on the exterior surfaces of the four shift rails. When any one of the four shift rails is moved out of the central neutral position, the interlock plate slides to extend into the grooves of the other three shift rails. Thus, the interlock plate prevents the other shift rails from moving until all are in the central neutral position.

Interlock assembly for vehicle transmission

A transmission includes a plurality of shift rails, each of which is axially movable forwardly and rearwardly from a center neutral position to respective gear engaging positions. The lower shift rails are provided for manual shifting among the lower gear ratios of the transmission. The highest shift rail is provided for selective manual or automatic shifting among the highest two gear ratios of the transmission. An idler rail is disposed adjacent to the highest shift rail. For manual shifting, the idler rail is connected to the highest shift rail, and a manually operable shift lever is used to move both the idler rail and the highest shift rail. For automatic shifting, the idler rail is disconnected from the highest shift rail, and an automatic shift member is moved into cooperation with the highest shift rail. Rotation of the automatic shift shaft causes corresponding movement of the automatic shift member. An electronic controller is provided for controlling the automatic shifting of the transmission in response to sensed operating conditions of the vehicle. A circuit is provided for sensing the rotational position of the automatic shift shaft and for generating an electrical signal which is representative of the actual position thereof, which is also representative of the actual position of the highest shift rail, to the electronic controller.

Vehicle transmission having manually shifted lower gears and

A transmission includes a plurality of shift rails, each of which is axially movable forwardly and rearwardly from a center neutral position to respective gear engaging positions. The lower shift rails are provided for manual shifting among the lower gear ratios of the transmission. The highest shift rail is provided for selective manual or automatic shifting among the highest two gear ratios of the transmission. An electronic controller is provided for controlling the automatic shifting of the transmission in response to sensed operating conditions of the vehicle. A circuit is provided for sensing the rotational position of the automatic shift shaft and for generating an electrical signal which is representative of the actual position thereof, which is also representative of the actual position of the highest shift rail, to the electronic controller. The transmission also includes a shift lever having an end which extends through an opening formed in a case. The end of the shift lever is movable in a first direction which is generally perpendicular to the shift rail so as to selectively cooperate with the shift rail. The shift lever is also movable in a second direction which is generally parallel to the shift rail so as to cause movement of the shift rail between first and second shift rail positions. A restraining plate is mounted on the case adjacent to the opening. The restraining plate has a portion formed thereon which limits movement of the end of the shift lever in the first direction. An interlock bracket is connected to the shift lever for movement therewith in the first direction. The interlock bracket engages the portion of the restraining plate to limit movement of the shift lever in the first direction.

Restraining plate and interlock bracket for vehicle transmission

An improved release mechanism for a hydraulically operated clutch. A tubular cylinder is formed between stationary inner and outer housings. A tubular piston has an inner end extending into the cylinder and has an outer end mounting a thrust bearing. Rotating clutch release levers engage the thrust bearing. One or more radial holes extend through the piston adjacent the inner end. Pins positioned in the holes extend into inner housing grooves which extend parallel to an axis of the release mechanism. The pins and grooves prevent rotation of the piston relative to the stationary housings, while allowing axial piston movement. A retainer ring is positioned in an annular groove in the exterior of the piston. The retainer ring both retains the pins in the piston holes and retains the piston in the cylinder.

Clutch release mechanism

A vehicle mechanical transmission includes a conventional shift lever which enables the vehicle driver to manually select lower gear ratios, and an automatic shifting mechanism which provides automatic shifting between selected higher ratios once the driver has moved the shift lever to an 'automatic' position. The transmission includes a plurality of shift rails which are individually and selectively moveable from a neutral position to two different gear positions. In accordance with the present invention, the shift lever is only coupled to mechanically shift a portion of the shift rails, typically those shift rails corresponding to the lower gear ratios. Once all the lower ratios have been selected, the driver can move the shift lever to an 'automatic' position. When in this position, the shift lever actuates an electronic control, which in turn automatically controls the shifting of at least one shift rail in accordance with the status of various monitored vehicle operating parameters. In addition to a conventional interlock between each of the shift rails, an auxiliary interlock system is provided to prevent the shift lever from being moved to the automatic position simultaneously with the shifting of a manually actuated shift rail. Further, the transmission includes a driver actuated manual override valve to cause the automatically shifted rail to return to its neutral position in the event of failure of the automatic shifting mechanism.

Vehicle transmission with manually shifted lower gears and automatically

A hill holder device for a vehicle manual transmission includes a releasable one-way clutch which is coupled to the countershaft of the transmission. In particular, the one-way clutch includes a sprag clutch having an inner race secured to the countershaft, and an outer race secured to the vehicle transmission case by means of a releasable locking mechanism. When the locking mechanism is in its locked position, the sprag clutch enables rotation of the countershaft in only one direction. Thus, if the transmission is in a forward gear and comes to a stop on an ascending grade, the hill holder will lock the vehicle drive train and prevent the vehicle from rolling back down the grade, without requiring the driver to apply the brakes. Similarly, if the vehicle is in a reverse gear and is stopped on a descending grade, the hill holder will prevent the vehicle from rolling in a forward direction down the grade. If necessary, the locking mechanism can be unlocked to release the hill holder in order to facilitate shifting in the event torque lock of the vehicle drive train locks the gear shifting components after the hill holder has become engaged on an inclined surface.

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Toledo, OH, United States of America

Kurt R Baer