Toyota Jidosha Kabushiki Kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Shigemichi Yamada

Hiroshi Ito

Teruo Akashi

Tadashi Nakagawa

Hiroaki Shinto

Mitsuyuki Noguchi

Minoru Yukiyasu

Yasuhide Kanbe

Kazuhiko Takemoto

Toshiyuki Ninomiya

A method is described for controlling a vehicle transmission mechanism which incorporates several selectively engagable power transmission systems each being selectively individually connectable between a first member and a second member for transmitting rotational power between them, with each such power transmission system including a clutching mechanism which can be selectively controlled either to freewheel in both rotational directions or to provide direct transmission of rotational power in one rotational direction only and to freewheel in the other rotational direction. While a first one of the power transmission systems which is for providing a certain speed stage is connected between the first member and the second member for transmitting rotational power between them at a gearing ratio appropriate to that speed stage, a second one of the power transmission systems which is for providing the speed stage one lower than that certain speed stage is also individually connected in parallel with the first power transmission system, with the particular clutching mechanism associated with the second power transmission system being controlled to be able to provide direct transmission of rotational power in one rotational direction only and to freewheel in the other rotational direction. Thus, the clutching mechanism of the second power transmission system freewheels. When a downshift is required, the clutching mechanism of the first power transmission system is disengaged, and the second power transmission system takes over the power transmission. A device for practicing this method is also described.

Transmission and transmission control device for providing downshifting

A method for controlling a vehicle transmission mechanism which incorporates several selectively engageable power transmission systems each being selectively individually connectable between a first member and a second member for transmitting rotational power between them, with each such power transmission system including a clutching mechanism which can be selectively controlled either to freewheel in both rotational directions or to provide direct transmission of rotational power in one rotational direction only and to freewheel in the other rotational direction. While a first one of the power transmission systems which is for providing a certain speed stage is connected between the first member and the second member for transmitting rotational power between them at a gearing ratio appropriate to that certain speed stage, a second one of the power transmission systems which is for providing a speed stage one higher or lower than that certain speed stage is also connected in parallel with the first power transmission system between the first member and the second member, with the clutching mechanism associated with the one of these power transmission systems which provides the lower speed stage being controlled to be able to provide direct transmission of rotational power in one rotational direction only and to freewheel in the other rotational direction. Thus, this clutching mechanism of the lower speed stage power transmission system freewheels. Thereby, smooth and snappy speed stage shifting is made available. A device for practicing this method is also described.

Transmission control method providing overlapped engagement of power

An actuation system for a transmission synchronizer, including a first member and a second member, the second member being pressed against the first member for synchronization of two relatively rotating elements, includes a variable pressure type actuator which selectively presses the second member against the first member, with a pressing force which is controllable to vary over a range so as to press the second member against the first member at a lower pressure in the initial phase of synchronization and at a substantially increased pressure at the end of synchronization.

Actuation system for transmission synchronizer providing regulated

A power supplying member supplies rotational power in a certain rotational direction to an input member of the transmission, and a power receiving member takes out power from a driven gear wheel shaft. Two driving gear wheel shafts extend parallel to the driven gear wheel shaft. First and second driving gear wheels are respectively rotatably mounted on the first and the second driving gear wheel shaft and meshed with a common driven gear wheel fixedly mounted on the driven gear wheel shaft. First and second synchromesh devices respectively selectively engage the first and the second driving gear wheel to the first and the second driving gear wheel shaft. First and second clutching mechanisms, each of which either can be disconnected so as to freewheel in both rotational directions or can be connected in the one rotational direction which is required for transmission of power through that clutching mechanism from the power supplying member rotating in the certain rotational direction so as to function as a one way clutch, are mounted to selectively transmit rotational power between the input member and the first and second driving gear wheel shafts respectively, both proximate to ends of the first and second driving gear wheel shafts closer to the input member.

Transmission with two parallel driving shafts bearing two driving gears

In a vehicle transmission system providing either manual or fully automatic operation according to selective switching-over of an operational mode selection means, a speed selection means for operation by a vehicle driver to select a range of speed stages available according to automatic speed change control by the transmission system in automatic operation thereof is also used in manual operation thereof as a means to set the transmission system to any forward speed stage desired by the vehicle driver in such a manner that its shifting to D, 3, 2 and L positions provide fourth, third, second and first speed stages, respectively.

Speed selection means for vehicle transmission system providing either

A power supplying member supplies rotational power in a certain rotational direction to a first member of the transmission, and a power receiving member takes out power from a second member. Several power transmission systems are provided between the first and the second member, which are selectively engageable so as to provide various speed stages between them. Each power transmission system has a clutching mechanism which either can be disconnected so as to freewheel in both rotational directions, or can be connected only in the one rotational direction which is required for transmission of power through that power transmission system, so as to function as a one way clutch. Thus shifting between the speed stages does not require delicate controlling of the clutching mechanisms. At least one of these clutching mechanisms can also be locked up so as to transmit rotational power in both rotational directions, and this enables engine braking to be made available, when the transmission is mounted in an automotive vehicle.

Transmission mechanism with parallel transmission systems including one

A power supplying member supplies rotational power in a certain rotational direction to an input member of the transmission, and a power receiving member takes out power from a driven gear wheel shaft. Two driving gear wheels shafts extend parallel to the driven gear wheel shaft. First and second pairs of gear wheels and first and second synchromesh devices are provided, one of each pair of gear wheels being mounted on the corresponding one of the driving gear wheel shafts and the other being mounted on the driven gear wheel shaft, and one of each pair of gear wheels being rotatably mounted on its gear wheel shaft and being selectively engaged thereto by the corresponding one of the synchromesh devices, while the other one of that pair of gear wheels is fixedly mounted on its gear wheel shaft. First and second clutching mechanisms, each of which either can be disconnected so as to freewheel in both rotational directions or can be connected in the one rotational direction which is required for transmission of power through that clutching mechanism from the power supplying member rotating in the certain rotational direction so as to function as a one-way clutch, are mounted to selectively transmit rotational power between the input member and the first and second driving gear wheel shafts respectively, both proximate to ends of the first and second driving gear wheel shafts that are closest to the input member.

Transmission with driven shaft and two clutching devices at the same

A power supplying member supplies rotational power in a certain rotational direction to a first member of the transmission, and a power receiving member takes out power from a second member. Several power transmission systems are provided between the first and the second member, which are selectively engagable so as to provide various speed stages between them. Each power transmission system has a clutching mechanism which either can be disconnected so as to freewheel in both rotational directions, or can be connected to transmit rotational power at least in the one rotational direction which is required for transmission of power through that power transmission system from the first member to the second member. A fluid torque converter is provided in the rotational power transmission path of only one of the power transmission systems which provides the lowest gearing ratio between the first member and the second member.

Transmission mechanism with parallel transmission systems including

Disclosed herein is a device for turning over a clutch pedal which comprises an arm for turning the clutch pedal over, a rod connecting the arm to the clutch pedal for joint rotation upon working of the clutch pedal and a tension spring provided between the arm and the clutch pedal. When the clutch pedal is worked until it reaches a predetermined position, the direction of force of the tension spring acting on the clutch pedal for returning it to its initial position is changed to assist forward movement of the clutch pedal. The device further includes a means connected to the rod for applying lateral force to the rod.

Device for turning over a clutch pedal

Disclosed herein is a vibration damping device for a mechanical clutch release system for a motor vehicle having a clutch cable comprising an outer cable mounted to the body of the motor vehicle and to the engine at one end and at the other end which is positioned forwardly of an exhaust pipe respectively and an inner cable mounted to a clutch pedal and to a clutch release fork at one end outwardly extending from the one end of the outer cable and at the other end outwardly extending from the other end of the outer cable respectively. The vibration damping device comprises a cylindrical body which is enclosingly secured to the inner cable between the other end of the outer cable and the clutch release fork to increase flexural rigidity of the inner cable.

Vibration damping device for a mechanical clutch release system for a

A clutch of the single-plate dry-disc type is structured to include annular friction facings secured to opposite surfaces of a supporting plate of a clutch plate and a plurality of recesses or shallow grooves are defined in the surface of one of the annular friction facings. The shallow grooves extend from the inner periphery of the one annular friction facing and terminate short of the outer periphery thereof. Accelerated air streams are introduced from the exterior through the fly wheel into the plurality of grooves so as to aid in separation of the friction facing of the clutch plate from the engaging surface of a fly wheel as a result of a hydrodynamic force created by the air streams. Furthermore, slots are defined in the surface of the friction facing in addition to the grooves so as to provide discharge passages for powder which has been produced due to wear or attrition of the friction facings.

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Toyota, Japan

Shigemichi Yamada