Mazda Motor Corporation

Hidehiko Mishima

Toshihisa Marusue

Tatsutoshi Mizobe

Kazunori Enokido

Shinya Kamada

Minoru Kuriyama

Takayuki Sumimoto

Toru Kawano

Yuzo Ohkawa

Keiji Bota

Shigeru Nagayama

Akio Matsumoto

Takuro Shigemura

Hiroto Kawano

Tatsutoshi Miyabe

Kotaro Ninomiya

A multiple stage automatic transmission includes a main transmission mechanism, a sub-transmission mechanism connected with the main transmission mechanism to for introduction of a torque therefrom, and a frictional element connected with the sub-transmission. The engaging force of the frictional element is changed at least by two steps in accordance with a shift mode without changing a hydraulic pressure applied for actuating the frictional element. A shift shock, therefore, can be obviated.

Multiple stage automatic transmission

In a control system for an automatic transmission, when successive order signals are emitted so that shift changes are accomplished over multiple shift stages, a shift change ordered by an initial order signal is carried out before a shift change ordered by a last order signal is carried out if a shift gear mechanism has already started its operation. However, a shift change ordered by a last order signal is carried out, without shift changes ordered by an initial order signal and intermediate order signals being carried out, if the shift gear mechanism has not started its operation.

Control system for automatic transmission

An automatic transmission includes a first transmission mechanism having a first shaft connectable to an output shaft of an engine, a second transmission mechanism associated with the first transmission mechanism, and having a second shaft in parallel with the first shaft, the second transmission mechanism being adapted for changing the torque speed of the first shaft, a hydraulic housing for accommodating a hydraulic control device for the second transmission mechanism, the second hydraulic housing being arranged above the second transmission mechanism, and an axis of the second shaft being positioned on either the same horizontal plane as an axis of the first shaft or a horizontal plane above the axis of the first shaft.

Automatic transmission

A hydraulic control system for controlling an automatic transmission includes a regulating valve which reduces a line pressure in accordance with a control pressure, provided in accordance with vehicle driving conditions, to provide a coupling pressure for coupling a specific one of frictional coupling elements of the automatic transmission. The regulating valve is enabled to provide the coupling pressure independently from the control pressure when a coupling pressure for another frictional coupling element higher than a specified level.

Automatic transmission control system

A particular shift control system is provided for an automatic transmission having a primary transmission, changeable to at least three primary gear ratios, and a secondary transmission, changeable to at least two secondary gear ratios. The primary and secondary transmissions combine to shift the automatic transmission to a plurality of forward speeds. The control system monitors the progression of change in the primary transmission gear ratio. In a specific automotive drive condition, the primary transmission changes from one primary gear ratio to another primary gear ratio via an intermediate primary gear ratio between the two primary gear ratios. This produces an increase or decrease in a primary gear ratio. At the same time, the secondary transmission decreases or increases, respectively, a secondary gear ratio so as to shift the automatic transmission from one forward speed to another, skipping an intermediate speed between the two forward speeds. The secondary transmission starts a change in a secondary gear ratio in an opposite direction only when a primary gear ratio of the primary transmission reaches the intermediate primary gear ratio.

Shift control system for automobile automatic transmission

The control system for an automatic transmission shifts the main transmission simultaneously with the auxiliary transmission at the time of a particular shift. At this time, a target gear ratio progress value of the auxiliary transmission is set for a gear ratio progress value indicative of a shift progress state of the main transmission. The main transmission is arranged so as to finish the shift control within a given target period of time, and the auxiliary transmission is arranged to implement the shift control by the feedback control so as to follow the target gear ratio progress value. The shift control of the auxiliary transmission is corrected by the learning control on the basis of a deviation between the target gear ratio progress value and the actual gear ratio progress value.

Control system of an automatic transmission

A control system for an automatic transmission including a main transmission and a subtransmission whose shift operation is carried out by hydraulically. The control system comprises a first device for adjusting a gear ratio advance of the main transmission, the gear ratio advance corresponding to a gear ratio change during the shift operation, a second device for adjusting a gear ratio advance of the subtransmission, the gear ratio advance corresponding to a gear ratio change during the shift operation, and a device for controlling the frist adjusting device and the second adjusting device during concurrent shift operations of the main transmission and the subtransmission so that the gear ratio advances of the main transmission and the subtransmission become equal to respective predetermined target gear ratio advances.

A hydraulic control system shifts an automatic transmission into at least a reverse range and a drive range having several forward speed gears by selectively coupling a plurality of frictional coupling elements, including a reverse coupling element. The control system includes a throttle, such as an orifice, for regulating hydraulic pressure applied to the reverse coupling element. A bypass circuit is provided in the control system for applying the hydraulic pressure, bypassing the throttle, to the reverse coupling element. The bypass circuit is opened when a specific operating condition of the automatic transmission of an engine is created, so as to apply the hydraulic pressure through the bypass circuit to the reverse coupling element to rapidly achieve a coupling of the reverse coupling element.

A throttle valve operating cam of an automatic transmission and an output control member of an automotive engine are interconnected so as to cooperate with each other by a cable consisting of an outer tube and an inner cable. The inner cable is connected to the throttle valve operating cam and the output control member and one end of the outer tube is connected first to the automatic transmission. The other end of the outer tube is regulated in position relative to a cable fitting member secured to the automotive engine and then fixed to the cable fitting member secured to the automotive engine.

Throttle cable fitting structure

An automatic transmission has a transmission gear mechanism for transmitting the engine output power by way of a plurality of power transmission paths, and friction engagement elements which are operated by a line pressure from a control valve to change the power transmission path through the transmission gear mechanism. Feed of the line pressure is controlled by a throttle pressure corresponding to the engine load and a governor pressure corresponding to the output speed of the transmission gear mechanism to effect gear shifting. A line pressure control system for controlling the line pressure comprises a regulator valve for regulating the line pressure, and a throttle modulator valve for determining a throttle modulator pressure for controlling the regulator valve according to the governor pressure and the throttle pressure so that the line pressure is increased with increase of the throttle pressure and is lowered with increase of the output speed of the transmission gear mechanism.

Line pressure control system for automatic transmission

An automatic transmission has a transmission gear mechanism for transmitting the engine output power by way of a plurality of power transmission paths, and friction engagement elements which are operated by a line pressure to change the power transmission path through the transmission gear mechanism to shift the gears. A hydraulic control system for the automatic transmission comprises a manual shift valve for changing the driving range, a plurality of shift valves each for effecting gear-shifting assigned thereto by controlling the feed of the line pressure to the friction engagement elements corresponding to the gear-shifting according to a throttle pressure and a governor pressure, and a range control valve which is provided in one of the hydraulic lines for transmitting the throttle pressure and the governor pressure to one of the shift valves to control transmission of the corresponding pressure to the shift valve according to the driving range determined by the manual shift valve, thereby changing the shift pattern according to the driving range.

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Hiroshima, Japan

Hidehiko Mishima