Wabco Westinghouse Fahrzeugbremsen Gmbh

Wabco Fahrzeugbremsen Gmbh

Wabco Gmbh

Wabco Gmbh & Co Ohg

Alfred Klatt

Erich Reinecke

Gunter Sebesta

Karlheinz Brinkmann

Harald Bortfeld

Wolfgang Gudat

Gunther Singbartl

Joachim Lehrmann

Lutz Danne

Gunter Seegers

Uwe Winkelholz

A device for controlling a gearshift which has a first pressure medium chamber and a second pressure medium chamber which are separated from each other by a piston, includes a first valve system, a second valve system, and an upstream third valve system by which the two pressure chambers are selectively connectable to a pressure medium source or to a pressure medium sink or can be closed off against both as a function of the output signals of an electrical control system. A pressure sensing device is installed between the pressure medium inputs of the two valve systems and the pressure medium outlet of the third valve system by which the pressure in each one of the pressure medium chambers of the gearshift can be measured or by which the pressure of the pressure medium source, i.e. the supply pressure, can be monitored. The electrical control system is designed in such manner that the actuation of at least one of the valve systems can be rendered dependent on at least the signals of the pressure sensing device, so that the gearshifting force and also the gearshifting speed of the gearshift can be controlled as a function of pressure.

Gearshift control device for a transmission

A method of shortening response time during a gear shifting operation process is applicable to a semi-automatic, electronically controlled transmission of motor vehicles, in particular utility vehicles, takes into account a driver's reaction time to reduce delay in clutch re-engagement. To initiate a gear-shifting operation in such a transmission, the driver actuates a shifting command emitter and at the same time disengages a clutch typically by depressing a clutch pedal. In response thereto, a newly selected gear is engaged in the transmission by an electronic system using outside force assistance, for example compressed fluid. The driver is informed via an acknowledgment device when the clutch can be properly engaged once more. In order to accelerate the entire gear shifting process, and concomitantly shorten the interruption of force flow attendant such shifting process, the acknowledgment device is actuated at a point in time prior to completion of transmission synchronization, when the electronic system has detected the beginning of the synchronization.

Method for shortening shifting time in a semi-automatic transmission

An actuating mechanism for a clutch implements an operator-dependent clutch actuation by sensing and transmitting an operator force signal, in the form of a target-value for the control circuit representative of the operator force, to a closed loop control system of the actuating mechanism. Greater sensitivity of operator-dependent clutch actuation is thereby achieved, as compared with a known automatic actuating mechanism for a clutch, in which the operator force alone controls an operated-initiated clutch actuation. Vehicles with automatic transmissions represent an important area of application for the invention.

Actuating mechanism for a clutch

A fluid-pressure-operated, three position working cylinder includes a cylindrical housing having a graduated bore formed therein and a movable primary piston dividing the bore into first and second pressure chambers. A movable secondary piston surrounds a portion of the primary piston and moves relative to the primary piston within the limits of a piston stop arrangement formed on opposing surfaces of the pistons. The piston stop arrangement includes an elastic stop on the primary piston which interacts with a sloped stop formed on the secondary piston so that upon initial insertion of the secondary piston onto the primary piston, the sloped stop compresses the elastic stop. The sloped stop includes a lip portion that can contact the elastic stop so as to restrain the secondary piston from further movement in one direction relative to the primary piston. A vent passage formed in the housing allows venting of the space between the two pistons. Pressurizing valves control the venting and pressurizing operations of the working cylinder. A check valve covering the vent passage prevents dirt and moisture from invading the graduated bore and piston space.

Three-position working cylinder having dual concentric pistons

A control apparatus is disclosed for a road vehicle, which contains a transmission control. The control apparatus includes, among other things, devices which recognize whether the vehicle is on the crest of a hill or in a valley, and whether the vehicle is travelling uphill or downhill over the crest of the hill or through a valley. For this purpose, the control apparatus includes a first devices which compares and calculates the difference between two stationary torques M.sub.stat calculated at different times which are necessary for nonaccelerating travel of the vehicle. In addition, the control apparatus contains a second devices which checks the mathematical sign of the difference .DELTA.M.sub.stat. Finally, the control apparatus contains a third devices which compares the stationary torque M.sub.stat with a specified value a. By way of the output signals of the above-mentioned apparatus, a unilateral impedance element is controlled, which blocks the shift signals of a shift command transmitter in the operating conditions described above.

Transmission control apparatus and method for vehicle traveling uphill

A gearshift range preconditioning system includes a gearshift device which, when manually-operated to effect a gear-change, initiates a signal to an electronic logic circuit which is coupled to the vehicle to receive vehicle-operating characteristics such as speed and engine RPMs. The electronic logic circuit evaluates this change request and the received operating characteristics in relation to predetermined optimum operating characteristics associated with optimum neutral gear ranges. The electronic logic unit then generates a neutral gear signal which is transmitted to a solenoid-valve-controlled neutral gear cylinder to effect operation of the vehicle transmission into the neutral position best suited for the specific vehicle-operating characteristics. An auxiliary range cylinder can effect selection of active gear positions between a high and a low state to achieve a doubling of possible active gear positions.

Gearshift range preconditioning system

A combination gear-selector, sensor device for use with vehicle transmissions having a plurality of gear positions and certain special gear functions and being controlled by an electronic circuit includes a shift lever having a first, square magnet which, when moved over distinct gear position sensors, indicates selection of a certain gear. A rod coaxially disposed within the shift lever has a second, rectangular magnet, displaced to one side of the first magnet, which when vertically moved over a first function sensor, indicates selection of that function which can be to skip a gear. A coaxial tube surrounds the rod member within the shift lever and has a third, rectangular magnet, displaced to an opposite side of the first magnet, which can be moved over a second function sensor to indicate selection of a second special function. The three magnet elements are oriented in an adjacent but opposing polarity relation and the sensors are polarity sensitive to prevent inadvertent indication by the wrong magnet, sensor arrangement. The special functions can only be selected in an active gear position due to the rectangular shape of the second and third magnets.

Combination gear-selector, sensor device

The invention relates to an apparatus for the protection of a clutch against overheating, specifically a clutch which is located between a combustion motor and a transmission. To ensure protection of the clutch against overheating for most operating conditions, there is an apparatus to determine the drive torque for the determination of the clutch torque or the drive torque transmitted by the clutch, an apparatus for the determination of the slip between the clutch input speed and the clutch output speed, a computer apparatus to determine the product of the clutch or drive torque to be transmitted and the slip, and a monitoring apparatus which combines the value of the product of the clutch torque to be transmitted and the slip with alarm delay times and compares the current slip time with the alarm delay times, and when the alarm delay times are exceeded by the slip times, gives an alarm signal.

Apparatus to protect a clutch from overheating

A transmission control is disclosed for a road vehicle for the determination of shift signals on downhill slopes. The invention includes a device for the determination of the stationary or constant speed drive torque M.sub.stat, which is necessary for the unaccelerated drive of the vehicle. The transmission control also includes a downhill gear classification device to coordinate the selection of a gear which is suitable for the downhill slope in question with a torque comparator in which various values of the stationary torque M.sub.stat are classified with the suitable downhill gear i.sub.x. A blocking element prevents a gear shift if a gear to be engaged by a shift command transmitter is higher than the suitable gear with the transmission ratio i.sub.x.

Transmission control apparatus and method for determining shift signals

A vehicle gearshift mechanism for a power-assisted transmission with a unilateral gearshift actuator which can be moved into speed selection positions and into a neutral position. The gearshift only has one speed selection position for a shift-up or shift-down, respectively. A respective optimum gear is assigned to the speed selection positions by an electronic evaluation control circuit. The evaluation control circuit receives signals representing the speed and the respective driving conditions of the vehicle to shift to the optimum gear.

Gearshift selection system for a power-assisted transmission

An apparatus for generating signal values that are representative of the vehicle engine's momentary drive torque, the weight of the vehicle, and the acceleration of the vehicle. The constant speed drive torque is then determined in a computing device which subtracts the product of the signal value of the vehicle weight and the signal value of the vehicle acceleration from the signal value for the momentary drive torque and a signal value that is representative of the constant speed drive torque of the vehicle engine is generated. This constant speed drive torque signal value is applied in the method for governing a vehicle control device.

Method and apparatus to determine constant speed torque on an engine

A power-assisted transmission with a gear shift suppressing arrangement in which the transmission is controlled so that the gears can only be changed when the clutch is completely disengaged. An electrical sensor senses and measures the movement of the clutch. The sensor is connected to an electronic evaluating circuit which controls the selection and the engagement of the gears. The evaluating circuit causes the disengagement of an old gear and initiates a serch for a newly selected gear when the clutch is depressed approximately two-thirds (2/3) of its full stroke. When the full clutch stroke has been reached, the newly selected gear is completely engaged. If the clutch is reengaged before the engagement of the newly selected gear, the transmission is shifted to the neutral position.

Power-assisted transmission having a gear shift suppressing arrangement

A vehicle gearshift selection system for a multiple-speed power-assisted transmission having a gearshift lever which is shiftable into a single shift-up position or a single shift-down position. A gear sensor for monitoring the position of the gearshift lever and connected to an evaluation control circuit. The electronic evaluation control circuit is connected to the multiple-speed power-assisted transmission and receives signals concerning the prevailing driving conditions of the vehicle for engaging an optimum higher gear when the gearshift lever is shifted-up and for engaging an optimum lower gear when the gearshift lever is shifted-down.

A gear positioning cylinder having forward, reverse, and neutral gear selection provided by a positioning rod attached to a main piston in which an auxiliary piston is telescopically arranged for compactness.

Gear positioning cylinder

A transmission gearshifting arrangement in which the gearshift lever is provided with a normal shift position and a fast shift position, the latter resulting in relative motion between the gearshift lever and a cam plate. This relative motion produces closure of a fast shift switch to signal the electronic evaluation circuit of the desired fast shift. In the absence of a signal, a normal shift speed is indicated. A pressure control valve capable of producing a bilevel rate or pressure is controlled by the evaluation circuit to cause a power cylinder to effect the gearshifting at either a normal or a fast speed.

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Wathlingen, Germany

Alfred Klatt