Honda Giken Kogyo Kabushiki Kaisha

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Tsunefumi Niiyama

Yukio Morita

Yoichi Kojima

Yorinori Kumagai

Takashi Hotta

Kimihiko Kikuchi

Hiroshi Nakayama

Takamichi Shimada

Tomoharu Kumagai

Shinichi Sakaguchi

Takeo Hiramatsu

Kazuhisa Yamamoto

Noboru Sekine

Atsushi Fujikawa

Haruhiko Yoshikawa

Hiroyuki Shimada

Eiji Kitsutaka

Kaoru Kajikawa

Hiroshi Ataka

Yasushi Ohmatoi

A hydraulic control apparatus for a continuously variable transmission which can produce stable drive pulley pressure and driven pulley pressure and also control the speed change time. The line pressure regulated by the regulator valve 22 is supplied to the control valve 24.sub.DR of the drive pulley 5 and to the control valve 24.sub.DN of the driven pulley 7. These control valves regulate the line pressure according to the PB pressure and the PC pressure output from the solenoid valves SOL-B, SOL-C, respectively, and produce the drive pulley pressure P.sub.DR and the driven pulley pressure P.sub.DN. When the PB pressure and the PC pressure are both zero, and P.sub.DR =P.sub.DN, the control apparatus maintains the same gear ratio. When the PB pressure is increased from zero while keeping the PC pressure at zero, i.e. P.sub.DR &gt;P.sub.DN, the gear ratio changes toward the high-speed overdrive. When the PC pressure is increased from zero while holding the PB pressure at zero, i.e. P.sub.DR &lt;P.sub.DN, the gear ratio changes toward the low-speed gear.

Hydraulic control apparatus for a continuously variable transmission

A system for controlling oil pressure of an automatic vehicle transmission having a plurality of fictional engaging elements (K1 ,K2,K3,B 1 ,B2) installed in the transmission for establishing a gear, a plurality of solenoid valves (SA and SE) at least one (SA) of which opens to supply the pressurized oil to at least one (K1) of the frictional engaging elements. The system also as a manual valve (20) whose spool moves in response to the selection of the selector lever for supplying the pressurized oil to the frictional engaging element bypassing the solenoid valve when the shift lever selects another gear range (1) in case of solenoid valve failure, and an underdrive engage control valve (30, 96) placed between the frictional engaging element and the switching valve for regulating pressure of the pressurized oil to be supplied to the frictional engaging. element in response to the pressurized oil outputted from the solenoid valve. In the system the underdrive engage control valve regulates the pressure of the pressurized oil to be supplied to the frictional engaging element in response to the pressurized oil supplied from the switching valve.

Oil pressure control system for automatic vehicle transmission

A hydraulic control apparatus for a hydraulically operated vehicular transmission has control valves corresponding to hydraulic engaging elements provided in the transmission. The supply and discharge of hydraulic oil to and from the corresponding hydraulic engaging elements are controlled by the control valves. The hydraulic control apparatus has an oil supply passage which is connected to a hydraulic oil source and into which a throttle is interposed. The oil supply passage is connected to oil passages which are on a downstream side of each of the control valves and which are to be communicated with the hydraulic engaging elements. Check valves are interposed in the oil supply passage to allow for the hydraulic oil flow only from the oil supply passage to the oil passages on the downstream side of each of the control valves.

Hydraulic control apparatus

The gear ratio of a belt-type continuously variable transmission is changed by increasing or decreasing the hydraulic pressure applied to an oil chamber for a drive pulley by a ratio control valve. A spool of the ratio control valve is driven by a normally opened solenoid valve and a normally closed solenoid valve. In a lower gear ratio range, the gear ratio is controlled by controlling the duty rate of the normally opened solenoid valve, and in a higher gear ratio range, the gear ratio is controlled by controlling the duty rate of the normally closed solenoid valve. When any trouble is generated, the gear ratio is held at an intermediate value by bringing both the duty rates of the normally opened solenoid valve and the normally closed solenoid valve into 0% or 100%. Thus, it is possible to finely control the gear ratio of the belt-type continuously variable transmission and, when any trouble is generated, the gear ratio can be held at the value intermediate between a LOW value and an OD value.

Control system for belt-type continuously variable transmission

A control apparatus for a hydraulically operated transmission for a vehicle has a control circuit portion for a lockup clutch and a solenoid valve for controlling a clutch which is engaged in a particular drive range. In another drive range in which the clutch is not engaged, an output pressure of the solenoid valve is inputted to the control circuit portion. A changeover valve can be switched between a first position in which a first oil passage to be connected to an output side of the solenoid valve in the drive range and a second oil passage to be communicated with the control circuit portion are brought into communication with each other, and a second position in which this communication is shut off. The changeover valve is switched to the first position by a hydraulic oil pressure which is generated at the time of establishing a predetermined transmission train other than the first-speed transmission train. An input oil passage inputs the first signal pressure to urge the changeover valve to the first position in interlocking with switching of the changeover valve to the first position. The first signal pressure is maintained to a constant pressure without influence by speed changing.

Control apparatus for hydraulically operated vehicular transmission

A hydraulic oil pressure changeover mechanism for switching an input pressure to a solenoid valve between a high pressure and a low pressure. The changeover mechanism is made up of: a pressure reduction valve to be switched between an operating condition for outputting a low hydraulic oil pressure and a non-operating condition for outputting a high hydraulic oil pressure; a changeover valve to be switched between a low-pressure position for inputting an output pressure from the pressure reduction valve to the solenoid valve and a high-pressure position for inputting a hydraulic oil pressure to be supplied without passing through the pressure reduction valve to the solenoid valve; and a control valve to be switched between a first position for outputting a first signal pressure to switch the pressure reduction valve to the non-operating condition and a second position for outputting a second signal pressure which operates in a direction to switch the changeover valve to the low-pressure position. The changeover valve can be switched to the low-pressure position when the second signal pressure and a third signal pressure are operated on the changeover valve.

Hydraulic control apparatus for hydraulically operated vehicular

A changeover valve is provided on an upstream side of solenoid valves for hydraulic engaging elements. The changeover valve is urged to the closed position by the hydraulic oil pressure of a plurality of hydraulic engaging elements which are concerned with the speed changing. At the time of failure in which three or more of the hydraulic engaging elements are simultaneously engaged, the changeover valve is changed over to the closed position to thereby lower the hydraulic oil pressure in the hydraulic engaging elements on the downstream side of the changeover valve, whereby the simultaneous engagement is prevented. In the closed position, a hydraulic oil pressure of a predetermined pressure is inputted to the changeover valve via an oil passage. The chattering of the changeover valve is thus prevented even if the hydraulic oil pressure in the hydraulic engaging elements may be lowered.

Control apparatus for hydraulically operated transmission

A hydraulic control unit for an automatic transmission having a plurality of power transmitting paths and a plurality of engaging clutches and/or brakes for selecting any one of the transmitting paths to set a gear position. The unit comprises a regulator valve for producing a line pressure, an operating pressure control valve for producing an operating pressure supplied to the engaging clutch or brake by regulating the line pressure from the regulator valve, and a line pressure switching valve for making the line pressure produced by the regulator valve low at a specified gear position when a target operating pressure set by the operating pressure control valve is lower than a specified value and making the line pressure high when the target operating pressure is higher than the specified value.

Hydraulic control unit for a vehicle automatic transmission

An automatic transmission on an automobile has an input shaft, an output shaft, a plurality of power transmitting paths disposed between the input and output shafts for establishing respective gear positions, and a plurality of engaging elements for selecting one of the power transmitting paths at a time. A shift controller disengages a previous-position engaging element and engages a next-position engaging element to switch from one of the power transmitting paths to another for thereby effecting a shift from a previous gear position to a next gear position. The shift controller provides a plurality of previous-position stages for controlling the previous-position engaging element with respective different characteristics to vary forces to disengage the previous-position engaging element in each of the gear positions, and a plurality of next-position stages for controlling the next-position engaging element with respective different characteristics to vary forces to engage the next-position engaging element in each of the gear positions. The shift controller executes the previous-position stages and the next-position stages to effect a shift between gear positions according to a change in the rotational speed of the input shaft, and executes all or selected ones of the previous-position stages and the next-position stages successively in order.

Apparatus for controlling automatic transmission

A hydraulic pressure control apparatus for an automatic transmission includes brakes and clutches to be engaged for selectively establishing gear positions in response to a controlling hydraulic pressure from a hydraulic pressure source. Two solenoid-operated valve assemblies are disposed in a hydraulic passage between the hydraulic pressure source and the brakes and clutches. The solenoid-operated valve assemblies are independently operable in response to respective control signals for controlling the supply of the controlling hydraulic pressure from the hydraulic pressure source to the brakes and clutches.

Hydraulic pressure control for automatic transmission

A planetary gear transmission typically for use on automobiles has first, second, and third planetary gear trains arranged coaxially with each other and each having elements including a sun gear, a carrier, and a ring gear. Two of the elements of each of the first, second, and third planetary gear trains are directly or disengageably coupled to elements of the other planetary gear trains. The transmission also has three clutch means and two brake means for selectively establishing a power transmitting path from an input shaft to an output gear member through the first, second, and third planetary gear trains. At least one of the first, second, and third planetary gear trains comprises a double-pinion planetary gear train, one of the sun gear and the carrier of the double-pinion planetary gear train being coupled to the input shaft and the other being nonrotatably fixed. The elements of the first, second, and third planetary gear trains are corotatably coupled into first, second, third, fourth, and fifth rotational members in a speed diagram, the third and fifth rotatable members being coupled to the input member, the fourth rotational member being coupled to the output member and. The carrier of the double-pinion planetary gear train may be coupled to the input shaft, and the sun gear thereof may be nonrotatably fixed.

Planetary gear transmission

A planetary gear transmission typically for use on automobiles has first, second, and third planetary gear trains arranged coaxially with each other and each having elements including a sun gear, a carrier, and a ring gear. Two of the elements of each of the first, second, and third planetary gear trains are directly or disengageably coupled to elements of the other planetary gear trains between input and output members. The elements of the first, second, and third planetary gear trains are corotatably coupled into first, second, third, fourth, and fifth rotational members the first, second, and fifth rotational members being coupled to the input member, the fourth rotational member being coupled to the output member. The planetary gear transmission also has a separating clutch disposed between the elements of the second rotational member, for disengageably connecting the elements of the second rotational member.

Clutch-separable planetary gear transmission

The solenoid valve 30 is mounted on the mounting member 10 with the inlet port section 31 positioned at the lower end thereof extending out downwardly from the bottom face of the mounting member 10, and this mounting member 10 is mounted on the base member 1 to cover the supplied oil path 2 and the discharged oil path 3 formed in the base member 1. The inlet port section 31 of the solenoid valve 30 extending out from the bottom surface of the mounting member 10 extends into the supplied oil path 2, thus the inlet port 31a and the supplied oil path 2 are communicated to each other. Furthermore, the outlet port 31b of the solenoid valve 30 is communicated to the discharged oil path 3 via the communicating groove 12 formed on the bottom surface of the mounting member 10. Also, the electric connector 21 is mounted on the mounting member 10 and the wiring members 25, 26 and 27 connecting the solenoid 36 of the solenoid valve 30 to this electric connector 21 are buried inside the mounting member 10.

Solenoid valve mounting assembly

A hydraulic relief valve according to the invention comprises; a housing having a clutch port communicating with a hydraulic chamber of a given hydraulic clutch and a drain port communicating with a drain, a spool inserted in the housing and being movable between an operational position at which the clutch port is isolated from the drain port and a relief position at which the clutch port communicates with the drain port, and biasing means to push the spool toward the operational position. The housing further includes an up-shift port communicating with a hydraulic chamber of an up-shift clutch which is engaged when the speed range is shifted up from the given speed range and a down shift port communicating with a hydraulic chamber of a down-shift clutch which is engaged when the speed range is shifted down from the give speed range. The hydraulic pressure in the chamber of the up-shift clutch is supplied into said housing through the up-shift port to push the spool toward the relief position when the speed range is shifted up. The hydraulic pressure in the chamber of the down-shift clutch is supplied into the housing through the down-shift port to push the spool toward the relief position when the speed range is shifted down.

Hydraulic relief valve for a hydraulic clutch

A planetary gear transmission typically for use on automobiles has first, second, and third planetary gear trains arranged coaxially with each other and each having elements including a sun gear, a carrier, and a ring gear. Two of the elements of each of the first, second, and third planetary gear trains are directly or disengageably coupled to elements of the other planetary gear trains. The transmission also has two clutch means and three brake means for selectively establishing a power transmitting path from an input shaft to an output gear member through the first, second, and third planetary gear trains. The first planetary gear train comprises a double-pinion planetary gear train, one of the sun gear and the carrier of the double-pinion planetary gear train being coupled to the input shaft and the other being disengageably coupled to a stationary member. The elements of the first, second, and third planetary gear trains are corotatably coupled into first, second, third fourth, and fifth rotational members in a speed diagram, the third and fifth rotatable members being coupled to the input member, the fourth rotational member being coupled to the output member.

Growing community of inventors

Saitama, Japan

Tsunefumi Niiyama