Abstract: A system for controlling a torque converter clutch in a vehicle powertrain includes a controller having an input for receiving powertrain operating parameter information. The controller is configured to determine a torque converter speed ratio based on the powertrain operating parameter information and to compare the speed ratio to a specified speed ratio limit. The controller is further configured to determine a target torque converter slip when the speed ratio exceeds or meets or exceeds the specified speed ratio limit; to compare the target slip with a desired slip value based on an vehicle noise, vibration or harshness (NVH) limit; and to control torque transmission of the torque converter clutch based on comparison of the target slip and the desired slip value. A method for controlling a torque converter clutch is also provided.

Abstract: A powertrain for a vehicle includes an engine having an output and a transmission selectively driven by the output of the engine. A torque converter is disposed between the engine and the transmission for selectively coupling the output of the engine to the transmission. A controller is in communication with the engine and the torque converter and controls a pressure: within the torque converter based on an input parameter supplied to the engine.

Abstract: A drivetrain of a motor vehicle has an internal combustion engine, an electric motor, a transmission, and a torque converter with a converter bypass clutch. The drivetrain is controlled such that, during an electric operating mode in which the internal combustion engine is deactivated and the electric motor is activated, and/or during a recuperation operating mode in which the internal combustion engine is deactivated and the electric motor is operated as a generator, the converter bypass clutch is permanently closed, at least between shift processes of the transmission, in order to bypass the torque converter.

Abstract: A lock-up clutch control apparatus for controlling a lock-up clutch (6) provided in a torque converter (5) installed between an engine (3) and a transmission (4), is disclosed. The lock-up clutch control apparatus has a differential pressure generator (7,8) which engages, causes a slip of or disengages the lock-up clutch by adjusting the differential pressure supplied to the lock-up clutch (6); a sensor (11/15) for detecting a rotational speed of the engine; a sensor (16) for detecting an input rotational speed to the transmission; and a controller (1). The controller (1) conducts proportional integration control by using a command signal to the differential pressure generator (7,8), so that an actual slip rotational speed, which is the difference between the engine rotational speed (Np) and input rotational speed (Ni) to the transmission, becomes a target slip rotational speed (Nt).

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of solenoids and valves in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A powertrain control apparatus that controls a powertrain including a lock-up clutch, which connects an engine, in which fuel supply may be cut off, directly to an automatic transmission. The control apparatus includes an output unit, a control unit, and a setting unit. The output unit outputs an instruction to lower engagement pressure for the lock-up clutch from a value at which the lock-up clutch is engaged to a value at which the lock-up clutch is disengaged. The control unit resumes the fuel supply to the engine when a predetermined lag time has elapsed since the instruction is output. The setting unit sets the lag time so that the lag time is shorter when a temperature of a combustion chamber of the engine is a first temperature than when the temperature of the combustion chamber of the engine is a second temperature which is higher than the first temperature.

Abstract: An ECT_ECU executes a program including the step of prohibiting a lockup clutch from engaging if the lockup clutch is disengaged and a number of revolutions or speed NE of an input shaft of a torque converter minus a number of revolutions or speed NT of an output shaft of the torque converter is smaller than a threshold value ?N (1).

Abstract: A power train for a machine is provided having a power source and a transmission, which includes a plurality of gears configured to produce multiple output ratios when selectively engaged. The power train also has a torque converter operatively coupling the power source and the transmission. A lockup clutch is associated with the torque converter, and the engagement of the lockup clutch is restricted so that the lockup clutch is engaged only when permissible gear ratios are actuated. The power train further has a controller in communication with the lockup clutch, the controller being configured to selectively engage the lockup clutch in either a first or a second shift mode with the number of permissible gear ratios being greater in the first shift mode than the second shift mode.

Abstract: A method and system to capture energy during regenerative braking while managing driveline disturbances by controlling locking and unlocking of a torque-converter clutch based upon operator input, typically throttle position or accelerator pedal position, vehicle speed, and engine load is offered. The exemplary vehicle has an engine, a torque converter with a clutch, and a transmission device. Vehicle kinetic energy is transmittable to an electrical machine using the transmission device and the torque converter. It includes monitoring an operator demand for power, engine operating speed, and, engine load; and, actuating the locking clutch for the torque converter based upon the operator demand for power, the engine operating speed, and, the engine load.

Abstract: A controlling method and system for a damper clutch of an automatic transmission control a damper clutch release condition according to a direct connection status of a damper clutch. The controlling method includes: determining whether the damper clutch is in a direct connection status in a power-on state or a direct connection status in a power-off state; detecting information of a vehicle if the damper clutch is in the direct connection status of the power-on or power-off state; determining whether a release condition of the damper clutch is satisfied; and releasing the damper clutch if the release condition of the damper clutch is satisfied.

Abstract: A hydraulic circuit arrangement for operating a hydrodynamic torque converter (1, 10) with a converter bridging clutch (11). The circuit arrangement comprises a hydraulic switching unit (3, 14) having at least one valve for controlling an inflow flow and a return flow of oil to the converter (1, 10) and the converter bridging clutch (11), an oil cooler (4, 15), a first line (5, 12) for acting upon the converter bridging clutch (11) with an engagement pressure (PWKzu) and a second line (6, 13) for acting upon the converter bridging clutch (11) with a disengagement pressure (PWKauf). The circuit arrangement comprises a bypass line (8, 17) which is connected directly with the oil cooler (4, 15) so as to bypass the hydraulic switching unit (3, 14).

Abstract: A torque converter including a clutch assembly and a channel. The clutch assembly includes: a reverse clutch with a piston plate, the reverse clutch controllably connecting a reverse stator and a drive hub; a forward clutch including the piston plate, the forward clutch controllably connecting a turbine and the drive hub; and a cavity partially formed by the piston plate. The channel supplies fluid to the cavity and to vent fluid from the cavity and the piston plate is displaceable in response to fluid pressure in the cavity to control operation of the reverse and forward clutches. In a preferred embodiment, forces associated with operation of the reverse and forward clutches are balanced within the clutch assembly. The torque converter also includes a clutch rotationally connected to a turbine and a ground and a one-way clutch rotationally connected to a forward stator and the ground.

Abstract: A clutch plate (6), as well as a method for operating a clutch (3), between the drive motor and the transmission (1) of a motor vehicle. The clutch plate includes a cylinder with a piston (14) and an actuator (15), such that a clutch release bearing (4), arranged co-axially to the central axis of the clutch, may be operated to apply an axial pre-tensioning force on the clutch release bearing and conduct an operating medium into the clutch plate for axially displacing the piston and/or the clutch release bearing. To simplify a clutch plate of this type and enhance its utilization, the clutch plate is configured and used for generating the pre-tensioning force.

Abstract: The present invention is a transmission used with a winch drum. The transmission includes a drive shaft, an output shaft, a hydraulic or pneumatic system, a cooling system, a gear coaxially mounted on the output shaft, and an electric motor for powering the gear. The drive shaft is adapted to drive the winch drum and includes a clutch disc extending generally radially outwards from the drive shaft. The clutch disc has a face. The output shaft coaxially surrounds at least a portion of the drive shaft and includes a friction surface extending generally radially inward. The friction surface has a face opposing the face of the clutch disc. The hydraulic or pneumatic system is adapted to bring the faces into contact, and the cooling system is adapted to remove heat from the friction surface via a fluid coolant.

Abstract: A method of releasing a lockup clutch for a fluid coupling assembly disposed between an engine and an automatically shiftable transmission during a negative engine torque mode of operation is provided. The method includes the steps of: A) determining a current engine torque value prior to commanding the engine to ramp to a target engine torque value; B) commanding the engine to a target engine torque value wherein the target engine torque value is one of a zero and near zero value; C) holding the engine at the target engine torque value; and D) releasing or disengaging the lockup clutch when the engine is operating at the target engine torque value. A powertrain is also provided having a controller sufficiently configured to operate according to the method of the present invention.

Abstract: A torque converter having a lockup clutch or a coupling device, for selectively providing a mechanical connection between a drive unit and a drive train. The lockup clutch (C) or coupling device has a driving part connected to the drive unit and a driven part connected to the drive train. The torque converter also has a control system for applying a first pressure in a sense to cause frictional engagement between the driving part and the driven part and a second pressure in a sense to cause disengagement of the driving part and the driven part. A differential between the pressures is progressively controllable by the control system so as to control the relative positioning between the driven part and the driving part.

Abstract: A vehicle automatic speed change power transmission control includes a control arrangement with overshoot/undershoot protection logic. The control is used with an electro-hydraulic pressure control module featuring a linear solenoid, and which supplies a hydraulically-actuated clutch configured to effect gear changes. The overshoot/undershoot protection logic is configured to detect when a commanded increase/decrease clutch pressure satisfies a clutch pressure threshold and to then activate the protection logic. Once the protection logic is activated, large command pressures increases/decreases are implemented in a series of stages having variable gains. The first stage has an aggressive gain and achieves 50-80% of the commanded clutch pressure. The second stage has a reduced gain and achieves 90% of the commanded clutch pressure. The third stage has a still further reduced gain and achieves about 100% of the commanded clutch pressure.

Abstract: A friction clutch which transmits motive power of a main drive shaft to an auxiliary drive shaft, a piston which generates pressing force against the friction clutch, a cylinder chamber which houses the piston movably in the axial direction, a pressure sensor which detects the oil pressure of the cylinder chamber, an hydraulic pump which feeds pressurized oil to the cylinder chamber, a motor which drive the hydraulic pump forward/reversely, and a controller which compares a command from a vehicle with a signal from the pressure sensor and controls the forward/reverse drive of the motor are provided. An hydraulic control valve unit feeds the pressurized oil to the cylinder chamber when the hydraulic pump is rotated forward, prevents outflow of the pressurized oil from the cylinder chamber when forward rotation of the hydraulic pump is stopped, and forcibly discharges the pressurized oil from the cylinder chamber when the hydraulic pump is reversely rotated.

Abstract: An oil pressure control circuit includes an oil pump for outputting an oil pressure from each of a first port and a second port, a lockup control valve for making a switchover between a state in which a secondary pressure is supplied to an engagement-side oil chamber of a torque converter and a state in which a secondary pressure is supplied to a release-side oil chamber of the torque converter, in accordance with an oil pressure supplied from a first solenoid valve, a garage shift control valve for maintaining a supply source of an oil pressure when an oil pressure is supplied from the first solenoid valve, and a port switchover valve for shutting off the first port of the oil pump from a line-pressure oil passage when an oil pressure is supplied from each of both the first solenoid valve and a second solenoid valve.

Abstract: A more efficient method for maintaining the hydraulic actuation of a selectively engageable torque transmitting device in a vehicle. The method includes generating a predetermined pressure level of a hydraulic fluid such as, for example, with a pump. The pressurized hydraulic fluid is transferred through an open valve and to a selectively engageable torque transmitting device such that the selectively engageable torque transmitting device is engaged. Thereafter, the valve is closed so that the predetermined pressure level of hydraulic fluid at the selectively engageable torque transmitting device remains relatively constant. Accordingly, the selectively engageable torque transmitting device remains engaged without continuously generating additional pressure such that the fuel economy of the vehicle is improved. A corresponding apparatus is also provided.

Abstract: An actuating device for a drive arrangement having a drive transmission operatively connected to a metering structure where a clutch is mounted adjacent to drive transmission, an actuating device is positioned to selectively engage the clutch such that the rotational force transferred from the drive transmission to the metering structure is selectively deactivated when the actuating member engages the clutch.

Abstract: A method of releasing a lockup clutch for a fluid coupling assembly disposed between an engine and an automatically shiftable transmission during a negative engine torque mode of operation is provided. The method includes the steps of: A) determining a current engine torque value prior to commanding the engine to ramp to a target engine torque value; B) commanding the engine to a target engine torque value wherein the target engine torque value is one of a zero and near zero value; C) holding the engine at the target engine torque value; and D) releasing or disengaging the lockup clutch when the engine is operating at the target engine torque value. A powertrain is also provided having a controller sufficiently configured to operate according to the method of the present invention.

Abstract: A system is provided for controlling the operation of powertrain, including an engine and a torque converter having a torque converter clutch. The system may include a torque governor for controlling a torque output of the engine and a speed governor for controlling a rotational speed of the engine. The system may further include a powertrain controller operable to receive a command selecting between first and second modes of operation. If the command indicates the first mode of operation, the powertrain controller may enable the torque governor and control the torque converter clutch to operate in accordance with a first clutch profile. If the command indicates the second mode of operation, the powertrain controller may enable the speed governor and control the torque converter clutch to operate in accordance with a second clutch profile that is different from the first clutch profile.

Abstract: A device and method for fluid delivery in a continuously variable transmission that includes a valve assembly, configured to distribute a fluid, having a first position and a second position. A forward clutch, a reverse clutch, and a torque converter are connected to the valve assembly. The valve assembly in the first position regulates either the forward clutch or the reverse clutch and opens the torque converter. In the second position, the valve assembly closes the forward clutch or the reverse clutch and regulates the torque converter. A controller commands the valve assembly to the first position and detects if the valve assembly is stuck in the second position. The controller is able to detect the valve assembly stuck in the second position and attempt to unstuck it while the continuously variable transmission is in drive.

Abstract: In lock-up capacity control apparatus and method for a torque converter, the torque converter is caused to have a converter state in which a relative revolution between input and output elements of the torque converter is free of limitation in a case where a lock-up capacity (L/Uprso) during a no-load state is equal to or larger than a shock determining lock-up capacity (?), during an acceleration slip lock up in which the lock-up capacity of the torque converter is augmented by means of a time series control which accords with a load state of an engine, and the torque converter is caused to be oriented toward a lock-up state in which the relative revolution is zeroed by continuing an augmentation of the lock-up capacity by means of the time series control in a case where the lock-up capacity during the no-load state is smaller than the shock determining lock-up capacity.

Abstract: In a drive train for a working machine, in particular, a wheel loader, the driving speed is preselected via a driving pedal (11) and the working hydraulic system is actuated via a selector lever (8), whose signals are fed to an electronic control unit (10) which regulates a drive engine (1) and a clutch (2) arranged between the drive engine (1) and a pump impeller (3) of a hydrodynamic torque converter in such a manner that an auxiliary drive (6) for a pump (7) of the working hydraulic system is operated at a sufficient speed, while the preselected driving speed is not exceeded.

Abstract: In a lockup control system of an automatic transmission with a lockup torque converter, a controller pre-stores a predetermined lockup control map including at least a predetermined coast slip lockup area, within which the system executes a slip lockup control mode under the vehicle's coasting condition, so that a speed difference between input and output speeds of the torque converter is brought closer to a predetermined value. The controller determines whether a first transition from the vehicle's driving condition to the predetermined coast slip lockup area occurs in a release mode of the lockup clutch or a second transition from the vehicle's coasting condition to the predetermined coast slip lockup area occurs in the release mode. When the first transition occurs, the lockup clutch is conditioned in the slip lockup control mode. When the second transition occurs, the lockup clutch is conditioned in the release mode.

Abstract: A control device for a lock-up mechanism arranged parallel with a hydraulic type torque transmitting mechanism that transmits rotatory power of a pump impeller connected with an output shaft of an engine to a turbine impeller connected with a wheel side element. The lock-up mechanism controls a slip value between the rotational speeds of the pump and turbine impellers in response to supplied hydraulic pressure. The control device calculates a target slip value, detects an actual slip value based on the rotational speed difference of the pump and turbine impellers, sets an intermediate slip value between the actual and target slip values, controls the hydraulic pressure to the lock-up mechanism so that the actual and intermediate slip values coincide, and reduces the intermediate slip value to a renewed value closer to the target slip value than the intermediate slip value when the actual slip value reaches the intermediate slip value.

Abstract: A vehicle control device for front and rear wheel drive vehicles, which have one wheel pair driven with an engine and the other pair driven with an electrical motor, and a torque converter with a lock-up mechanism controlling the engagement amount, has a lock-up control means changing the target slip amount to be set in accordance with driving conditions, a motor drive power setting means which sets the drive power distribution ratio of the motor and a compensation means which compensates the target slip amount according to the drive power distribution ratio set by the motor drive power setting means. The control device enables the setting of the optimum slip ratio of the torque converter to improve the fuel consumption, avoiding problems associated with: noise and vibration during the motor assisting.

Abstract: A vehicular automatic transmission TM has a torque converter TC connected to the engine E and an automatic transmission mechanism (gear trains 13a, 13b, 14a, 14b) connected to the output side of the torque converter, the drive power from the engine for which gear shifting is performed via the torque converter and the automatic transmission mechanism is transmitted to the wheels and the vehicle is driven. The control apparatus for this automatic transmission mechanism has a towing state presumption device that presumes based on the driving conditions that the vehicle is in a towing state, and a lockup engagement increase mechanism that increases the degree of engagement of the lockup clutch of the torque converter when it is determined via the towing state determination device that the vehicle is in a towing state.

Abstract: A lock-up control system for a torque converter which includes a lock-up clutch engageable under control of an engaging capacity of the lock-up clutch to thereby lock up input and output elements of the torque converter. The control system is operative during coasting in a lock-up region requiring engagement of the lock-up clutch, so as to bring the engaging capacity of the lock-up clutch to a coast lockup capacity smaller than a lock-up capacity under a driving condition at the same vehicle speed. The control system is further operative when an engine braking range is selected during coasting in the lock-up region, so as to bring the engaging capacity of the lock-up clutch to a value greater than the coast lock-up capacity, preferably to a controlling maximum value.

Abstract: A pre-compensator equipped slip control system for a lock-up torque converter employing a lock-up clutch, includes a slip-rotation control section that begins to calculate a compensated target slip rotation from a time when an actual slip rotation between input and output elements of the torque converter becomes less than a predetermined slip-rotation threshold value after shifting from a torque-converter action area to a slip-control area, so that the actual slip rotation is brought closer to the compensated target slip rotation. Also provided is a feedforward control section that determines a lock-up clutch engagement pressure by way of feedforward control during a period of time from a time when the torque converter is shifted from the torque-converter action area to the slip-control area to the time when the actual slip rotation becomes less than the predetermined slip-rotation threshold value.

Abstract: An apparatus for controlling a lock-up clutch disposed in a drive system of an automotive vehicle which includes a lean-burn engine provided with a turbocharger. The apparatus is arranged to place the lock-up clutch in a fully engaged state and/or a slip control state while a running condition of the automotive vehicle is in a predetermined engaging area or slip control area of the lock-up clutch. The apparatus includes an engaging-area changing device operable to change the engaging area of the lock-up clutch, on the basis of a turbocharging pressure established by the turbocharger, and/or slip-control-area changing means for changing the slip control area, on the basis of the turbocharging pressure.

Abstract: An apparatus for controlling a lock-up clutch disposed in a drive system of an automotive vehicle which includes a lean-burn engine provided with a turbocharger. The apparatus is arranged to place the lock-up clutch in a fully engaged state and/or a slip control state while a running condition of the automotive vehicle is in a predetermined engaging area or slip control area of the lock-up clutch. The apparatus includes an engaging area changing device operable to change the engaging area of the lock-up clutch, on the basis of a turbocharging pressure established by the turbocharger, and/or slip-control-area changing means for changing the slip control area, on the basis of the turbocharging pressure.

Abstract: Clutch disengagement shock resulting from the sudden release of torsional torque is prevented and ride-feeling at the time of changing gears or starting at a low-speed gear stage in an automatic clutch vehicle is improved. In a clutch control arrangement for controlling the engagement and disengagement of a friction-type clutch (1) by means of a clutch actuator (3) and a control unit (14), clutch disengagement speed is reduced when, at least, a gear-changing operation by a driver is detected, and the transmission (20) is in a low-speed gear stage. Even when the clutch is automatically disengaged at gear change, since disengagement speed is reduced if the current gear stage is a low-speed gear stage, the clutch (1) is not abruptly disengaged, enabling the prevention of clutch disengagement shock due to the sudden release of torsional torque.

Abstract: A device for limiting slip of a torque converter at its high temperature condition performs a slip limiting control by reducing slip rotation between an input element and an output element of the torque converter in a low-load operation region of an engine is carried out, or a lockup control for eliminating the slip rotation. The region of the slip control is expanded to a high-load operation region of the engine, when the temperature of torque converter hydraulic oil is not lower than a predetermined temperature.

Abstract: After an engine (1) has started, a controller (6) starts determining whether lockup should be prohibited or permitted based on the cooling water temperature of an engine (1) or the oil temperature of a transmission (2). Once it has been determined that lockup should be permitted, the controller (6) stops determining whether lockup should be prohibited or permitted until the next time the engine (1) is started. In this way, once the conditions for determining that lockup should be permitted hold, lockup prohibition or permission based on the engine cooling water temperature or transmission oil temperature is no longer determined, so repeat engaging and disengaging of the lockup clutch (5) due to fluctuations of engine cooling water temperature or transmission oil temperature, is prevented.

Abstract: A system for protecting one or more drive line components from excessive inertial torque includes a torque converter disposed between an internal combustion engine and a transmission coupled thereto, wherein the torque converter is responsive to computer control to operate in a lockup mode to directly couple the engine output shaft to the transmission input shaft and otherwise in a torque converter mode. Under conditions wherein drive line acceleration exceeds an acceleration threshold, wherein the acceleration threshold preferably corresponds to the weakest of the drive line components, a control computer is operable to force the torque converter to operate in a torque converter mode of operation to thereby electronically disengage direct connection between the engine and the transmission and then to modify fueling to thereby protect the various drive line components from damage due to excessive engine inertial torque.

Abstract: A vehicle control system is described for controlling a torque converter coupled to an engine. The controller engages the torque converter before negative powertrain output becomes less than a predetermined value. Such an approach allows for torque converter locking in the negative powertrain output region. Such an approach is especially suited to vehicles having certain torque converters, which are difficult to lock at large negative torque values.

Abstract: A device for limiting slip of a torque converter at its high temperature condition performs a slip limiting control by reducing slip rotation between an input element and an output element of the torque converter in a low-load operation region of an engine is carried out, or a lockup control for eliminating the slip rotation. The region of the slip control is expanded to a high-load operation region of the engine, when the temperature of torque converter hydraulic oil is not lower than a predetermined temperature.

Abstract: The subject invention involves a compressor starting torque converter (CSTC) to enable starting up single-shaft gas turbine driven compressor sets, such as in a liquified natural gas (LNG) plant. The system includes a single-shaft gas turbine with an output shaft coaxially connected to the input shaft of the CSTC's torque converter, in turn whose output shaft drives the process load centrifugal compressor. The CSTC operates as a fluid coupling whereby the gas turbine and the compressor shafts are coupled via the working fluid (oil). Once the process load compressor is up to speed, a lock up device is engaged to mechanically couple the gas turbine directly to the compressor and then the torque converter is drained. The impeller and turbine wheel of the CSTC are undersized with regard to the maximum shaft power requirement of the compressor.

Abstract: In a damper clutch control method of a hydraulic control system for automatic transmissions, a damper clutch operation condition is first calculated according to signals from a drive condition detecting part, then it is determined if the calculated value is within a damper clutch operation range on a level road. When the calculated value is within the damper clutch operation range, the pressure control solenoid valve is controlled such that the damper clutch can be operated by hydraulic fluid fed through the damper clutch control valve, then it is determined if a damper clutch release condition on a level road is satisfied or not. When the damper clutch release condition is satisfied, the pressure control solenoid valve is controlled such that the damper clutch can be released by releasing hydraulic fluid from the damper clutch.

Abstract: A lock-up controller is provided for shifting a torque converter of a vehicle from the lock-up state to the unlock state when the accelerator pedal is depressed at a speed larger than a predetermined speed when the vehicle is coasting. The controller is further functioning to prevent the torque converter from shifting to the lock-up state when the torque converter has been shifted to the unlock state and the vehicle speed is within the predetermined re-lock-up prevention speed range so as to avoid frequent lock-up/unlock operation of the torque converter.

Abstract: The invention prevents clutch disengagement shock resulting from the sudden release of torsional torque and improves ride-feeling at the time of changing gears or starting at a low-speed gear stage in an automatic clutch vehicle. In a clutch control arrangement for controlling the engagement and disengagement of a friction-type clutch (1) by means of a clutch actuator (3) and a control unit (14), clutch disengagement speed is reduced when, at least, a gear-changing operation by a driver is detected, and the transmission (20) is in a low-speed gear stage. Even when the clutch is automatically disengaged at gear change, since disengagement speed is reduced if the current gear stage is a low-speed gear stage, the clutch (1) is not abruptly disengaged, enabling the prevention of clutch disengagement shock due to the sudden release of torsional torque.

Abstract: A clutch control device of a continuously variable transmission is provided with a clutch control part, which controls the engagement state of a clutch. The minimum engaging force, which is capable of maintaining the completely engaged state of the clutch, is predetermined to increase according to an increase in engine torque. The clutch control unit has an engaging force setting part, which sets the target engaging force for the clutch to a higher value than the minimum engaging force by a predetermined value. The clutch control unit controls the engagement state of the clutch so that the actual engaging force for the clutch can be higher than the minimum engaging force by the predetermined value. Therefore, the clutch control device can improve the fuel economy and prevent a shift shock when there is a rapid increase in the engine torque.

Abstract: A hydraulic control apparatus for automatic transmissions, capable of adapting the apparatus to a change in the specifications for a lockup clutch which causes the relationship between the supplying and discharging of a hydraulic pressure for a lockup control operation to be reversed with respect to the connection of oil passages. A valve body of the hydraulic control apparatus is formed by laminating at least two members on each other, and has a valve for regulating a hydraulic pressure supplied to a lockup clutch of a hydraulic transmission unit, a control unit for applying a signal pressure to the pressure regulating valve, a source pressure oil passage for supplying a basic pressure for a pressure regulating operation, and drain oil passage communicated with a drain port. The pressure regulating passage is provided at both sides of a port, which communicates with a lockup oil chamber via an oil passage, with a port communicating with an oil passage, and a port communicating with another oil passage.

Abstract: In machines having electro-hydraulic transmission controls, it is desirable to ensure that in the event of an electrical malfunction or power failure the transmission responds appropriately. In the subject invention, a system is provided in a transmission which in the event of an individual clutch solenoid fault (short-to-battery, short-to-ground, and open circuit fault) keeps the machine in gear and protects the transmission from damage. A short-to-battery fault will allow shifting to an available gear that utilizes the faulted clutch. If there is a short-to-ground or open circuit fault then the transmission will latch the current gear or shift to a predetermined gear that does not utilize a faulted clutch.

Abstract: A control apparatus for an automatic transmission of a vehicle having a forward friction element for engaging or disengaging a turbine shaft with the automatic transmission in a forward running direction and a lock-up clutch for directly transmitting a rotation of an engine to the turbine shaft, comprises an abrupt deceleration control means for disengaging the forward engagement element and the lock-up clutch when an abrupt deceleration of the vehicle is detected, and a restoring means for canceling the abrupt deceleration control means and for restoring the forward friction element to an engagement state when an accelerator pedal is depressed for acceleration.

Abstract: A transmission including a torque converter to transfer power from a driving engine to a driven device through a series of fluidly-activated clutches, particularly for use with industrial applications. By using a self-contained fluid system to engage the clutch at the idle speed of the driving engine, the transmission is provided with a positive neutral feature. The transmission is adaptable to all industrial engine housings. Additional optional features of the transmission include an auxiliary drive, a reverse and single or additional forward gears, and a fluid cooler. The transmission further includes a transmission output shaft supported by a bearing assembly that may be designed for side loading. The transmission provides the benefits of increased performance in torque demanding applications, self-lubricating features that eliminate grease fittings, load dampening, an auxiliary drive, and a throttle/clutch engagement system that eliminates clutch damage caused by improper high speed engagement.

Abstract: A system for controlling output torque characteristics of an internal combustion engine includes a control computer operable to control the output power/torque of the engine that is coupled to a transmission through a torque converter. The system is operable to determine an engine speed range of interest and limit engine output power/torque to a predefined maximum value if the current engine speed is within the engine speed range of interest when the torque converter is operating in torque converter mode (i.e., not in lockup mode). The predefined maximum value of engine output power/torque is preferably a maximum horsepower value that may be a constant value or a function of engine speed within the engine speed range of interest. Alternatively, the predefined maximum value of engine output power/torque is a dynamic function of a torque ratio of the torque converter and a predefined turbine torque limit.