Mazda Motor Corporation

Koichi Yamamoto

Shinya Kamada

Tatsuhiko Iwasaki

Takamichi Teraoka

Tomoo Sawazaki

Yasunori Kanda

Akinobu Aoki

Hiroshi Shinozuka

Takeyoshi Kawa

Naotaka Hirami

Masakazu Hombo

Kazushi Kurokawa

Kenji Sawa

Naomune Moriyama

Reiji Kikuchi

Takahito Yokouchi

Fumiaki Baba

Toshiyuki Kikuchi

Ayumu Doi

Mitsutoshi Abe

Eiji Mito

Takahiro Kyohzuka

Masaki Kadokura

Shinji Shimaoka

Satoru Kawasoe

Yuzou Ohkawa

Hideaki Akaboshi

A heat exchanger, which performs heat exchanging between a lubricating oil circulating within a transfer device disposed behind an engine and an engine coolant, also functions as a mass member of a dynamic damper. The heat exchanger is disposed at an upper face of a transfer case via a resilient member. Herein, the resilient member is comprised of a first metal plate, a second metal plate, and a rubber member interposed between the first and second metal plates, and there are provided lubricating passages flowing within the resilient member. Accordingly, there can be provided the vibration suppression device of the power train that can suppress vibration properly regardless of the temperature changing and advantage the weight reduction without requiring any new disposition space.

Vibration suppression device of power train

A control system for an automatic transmission having at least a friction coupling element which is coupled with a hydraulic pressure increasing by way of a leveled transitional pressure has an accumulator which discharge a high level of pressure accumulated therein into the friction coupling element during a gear shift under the condition where the line pressure is low.

Control system for automatic transmission

A control system for an automatic transmission having friction coupling elements, at least one of which is locked in 3rd and 4th gears and unlocked in 1st and 2nd gears, includes a first shift valve shiftable between 3rd and 4th gears, and second shift valve shiftable between in 2nd gear and 1st gear in which engine brake available, and a solenoid valve providing control pressure which is selectively directed to these shift valves and cause them to shift so as to lock or unlock the friction coupling elements.

Automatic transmission control system

A control system for an automatic transmission having a transmission gear mechanism and a plurality of friction coupling elements which are selectively locked and unlocked with hydraulic oil to change power transmission paths to place the automatic transmission into desired available gears, a first one of the friction coupling elements having a locking pressure chamber and an unlocking pressure chamber and being locked when operating oil is supplied into only the locking pressure chamber and unlocking when operating oil is coincidentally supplied into the locking pressure chamber and the unlocking pressure chamber, and a second one of the friction coupling elements having a locking/unlocking pressure chamber in communication, with the unlocking pressure chamber of the first friction coupling element and being locked only when operation oil is supplied into the locking/unlocking pressure chamber. The control system includes a transition level control for controlling a pressure level of transitional pressure of operating oil increasing in pressure level while being supplied to the locking/unlocking pressure chamber of the second friction coupling element during a first specified gear shift with a first friction coupling element and the second friction coupling element are simultaneously unlocked and locked, respectively, and decreasing while being discharged from the locking/unlocking pressure chamber of the second friction coupling element during a second specific gear shift wherein the first friction coupling element and the second friction coupling element are simultaneously locked and unlocked, respectively, and a transitional duration control for controlling a duration time of the transitional pressure during any one of the first and second specific gear shifts.

A hydraulic control system for an automatic transmission having at least a forward clutch which is unlocked in a fourth gear and locked in other forward gears and a lock-up clutch for coupling input and output elements of a torque converter together is equipped with a pressure control valve for controlling operating pressure for the forward clutch, a lock-up control valve for connecting and disconnecting the first valve from the lock-up clutch, a pressure line through which control source pressure is introduced into the forward clutch while the first valve is in communication with the lock-up clutch, and a shift valve for discharging the control source pressure from the pressure line.

Forward clutch and lockup clutch control in an automatic transmission

A control system for an automatic transmission having at least a friction coupling element which is coupled with a hydraulic pressure increasing by way of a leveled transitional pressure has an accumulator which discharge a high level of pressure accumulated therein into the fiction coupling element during a gear shift under the condition where the line pressure is low.

In a four-wheel-drive motor vehicle of transversely-disposed engine type, an engine and a transmission are disposed so as to be longitudinally offset from each other and to locate a gravitational center thereof in a rearward position of an axle of front wheels, and in addition an output shaft of the transmission and a center differential are disposed coaxially. With this arrangement, imbalanced weight distribution of the vehicle body on front wheels can be corrected, and a longitudinally-compact layout of the power transmission device can be obtained. Further, a height of a bonnet can be lowered.

Four-wheel-drive motor vehicle of transversely-disposed engine type

A four-wheel-drive motor vehicle with a transversely-disposed engine of such construction that a front differential which distributes motive power from a center differential to the right and left front wheels is arranged on the front axle and in the rear of the front differential, an engine and a transmission are arranged. By this arrangement, one-sidedness of the vehicle body weight to the front wheels can be relieved.

In the four-wheel-drive motor vehicle of transversely-disposed type, a front differential and a center differential are arranged coaxially on the axle line of front wheels, and an engine and a transmission are disposed transversely to the vehicle body in the rear of these differentials. This arrangement can relieve one-sided action of the vehicle body weight on the front wheels.

Four-wheel drive motor vehicle of transversely-disposed engine type

An engine control system for a vehicle having an automatic transmission in which the gear-shifting is automatically done on the basis of a predetermined shift pattern comprises an engine output control system for controlling the output power of the engine, a detecting system which detects actual shifting action of the gear train mechanism of the automatic transmission, and an engine control unit which receives a signal from the detecting system and delivers to the engine output control system a control signal for temporarily lowering the engine output power while the actual shifting action of the gear mechanism is in progress.

Engine control system for vehicle with automatic transmission

A hydraulic control system comprising frictional device provided with pistons and a pair of frictional members controlled to be moved between an engaged position in which the frictional members are frictionally engaged with each other and a disengaged position in which the frictional members are disengaged from each other by a hydraulic pressure so as to switch a power transmitting path in the automatic transmission for accomplishing a gear shift operation among the plurality of the shift gear stages, a hydraulic supply means for applying the hydraulic pressure to the piston. A restriction control is carried out in a manner that an increase of the hydraulic pressure is restricted by a predetermined period at an initial stage of the gear shift operation wherein the frictional members are being moved to the engaged position and producing an initial engaging force therebetween.

Hydraulic control system for automatic transmission

A control system for an automatic transmission employed in a vehicle comprises a torque converter coupled with an engine, power transmitting gear arrangement disposed at an output end of the torque converter, a speed change mechanism for giving rise to speed change in the power transmitting gear arrangement, a fluid servo control device having an applying chamber and a releasing chamber to each of which a fluid is supplied and operative to cause the speed change mechanism to work, and an additional control device for controlling the fluid servo control device under a situation in which the fluid in the releasing chamber of the fluid servo control device is so controlled as to have one of speeds in the power transmitting gear arrangement. The fluid servo control device is controlled by the additional control device to be in a first condition wherein the fluid is supplied to the applying chamber and in a second condition wherein the fluid is drained from the applying chamber selectively in response to the operating condition of the engine or the travelling condition of the vehicle.

System for controlling rate of speed change in automatic transmission

A control system for automatic transmission employed in vehicle comprises a torque converter coupled with an engine, a power transmitting gear arrangement coupled with the torque converter, a speed change device for giving rise to speed change in the power transmitting gear arrangement, a valve arrangement for controlling an operation fluid to be supplied to and drained from the speed change device, a revolving speed sensor for detecting the revolving speed of an input or output portion of the power transmitting gear arrangement when the shifting-down to a low speed with which an engine brake effect is to be obtained from a high speed in the power transmitting gear arrangement is carried out, and a control device for selecting, as the low speed of a target of the shifting-down, a first low speed with which the engine brake effect can be obtained and a second low speed with which the engine brake effect can not be obtained alternatively in response to the revolving speed detected by the revolving speed sensor. The control device selects further the first low speed after the second low speed is selected for a predetermined period of time on the occasion of the shifting-down.

Control systems for automatic transmissions

A vehicle automatic transmission having a torque converter and a multiple-stage gear mechanism. When the vehicle is stopped and the shift lever is in the D-range, the gear mechanism is shifted to the highest gear stage if the vehicle brake is engaged and the engine is idling, so that transmission of the engine idling vibrations to the vehicle body can be prevented by the transmission.

Control of a vehicle automatic transmission

In a gear-shifting control system for an automatic transmission, gear-shifting is normally controlled according to main gear-shifting characteristics in which gear-shifting points are determined using the turbine rpm as a parameter. On the other hand, gear-shifting is effected according to backup gear-shifting characteristics which are determined using the vehicle speed as a parameter in case of failure of the part for detecting the turbine rpm.

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Hiroshima, Japan

Koichi Yamamoto