Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Tetsuya Mochizuki

Shunsuke Yoshida

Yutaka Ishikawa

Tatsuyuki Ohashi

Yuya Tachibanada

Tomoaki Mukai

Shoichi Tanizawa

Shinichi Nishio

Shoji Asatsuke

Yoshimichi Tsubata

Naohisa Morishita

Kazuma Hatakeyama

Koichi Fushimi

Kazuo Okada

Hirotaka Yokota

Shouji Asatsuke

Ryohei Yamagishi

Hiromitsu Ishibashi

Jiro Obinata

Toshiaki Maeda

Masaya Tamai

Shyoji Arai

A control apparatus of an automatic transmission, which includes a mechanical engaging mechanism functioning as a brake, includes a determination unit determining, when a selected gear is a lowest forward speed gear, and the mechanism is in a second state, whether to switch the mechanism to the first state, and a switching processing unit switching the mechanism to the first state based on a determination result. In the first state, only rotation of a predetermined rotational element provided in planetary gear mechanisms in a first direction is restricted. In the second state, rotation of the predetermined rotational element in both the first and second direction is restricted. The determination unit determines to switch the mechanism to the first state at least on condition that a driving force is larger than a predetermined driving force.

Control apparatus

A parking lock apparatus includes an engaging mechanism, a slider, a hydraulic circuit, and a processor. The engaging mechanism is to prevent a rotation of a rotating body when the engaging mechanism is in a mechanical engagement state. The slider is to switch a state of the engaging mechanism between the mechanical engagement state and a mechanical disengagement state in accordance with a position of the slider. The hydraulic circuit is to change the position of the slider. The processor is configured to increase line pressure in the hydraulic circuit when the engaging mechanism is in the mechanical engagement state.

Parking lock apparatus

A parking lock apparatus includes a parking gear rotatable together with a rotating body of a transmission. A slider is to be switched between a parking lock position in which a parking pawl is in engagement with the parking gear and a parking release position in which the parking pawl is out of engagement with the parking gear. A hydraulic circuit includes a third oil passage through which a first line pressure is applied to push the slider toward the parking release position, a fourth oil passage through which a second line pressure is applied to push the slider toward the parking lock direction, and a hydraulic cut valve provided in the third oil passage to be opened when a difference between the first line pressure and the second line pressure is higher than or equal to a threshold pressure when applying line

A simple attachment structure with a minimized piece-part count, allowing easy grounding connection of the solenoid valve. The solenoid valve includes a body section with a built-in electromagnetic coil and a shaft-shaped valve section continued coaxially to the body section. An insertion hole for inserting the valve section in the control body is formed to the control body. The control body includes a locking mechanism composed of a locking piece with elasticity connected to a ground terminal of the electromagnetic coil and projecting out from an outer periphery of the body section and a concave portion provided on an upper surface of the control body. By inserting the valve section into the insertion hole, the locking piece elastically engages with the engaged part to lock the solenoid valve, and the solenoid valve is grounded through a contact between the locking piece and the engaged portion.

Attachment structure for solenoid valve

In a vehicular parking lock device, supplying a hydraulic pressure from pressure regulation of a line pressure by a linear solenoid valve to a hydraulic brake via a switching valve operated by a first solenoid valve enables a transmission to carry out a shift change. If desired that a parking lock is not operated when an engine stops, the hydraulic pressure stored under pressure in an accumulator is discharged to a drain oil passage by connecting the linear solenoid valve selectively to the drain oil passage by the first solenoid valve, thereby making it possible to prevent the hydraulic pressure stored under pressure in the accumulator from being supplied to a locking oil chamber at the other end of the hydraulic actuator. The first solenoid valve is used for both controlling the operation of the hydraulic brake and discharge of the hydraulic pressure stored under pressure in the accumulator.

Vehicular parking lock device

A hydraulic control device for an automatic transmission includes a cut-off valve and a line pressure detector. The cut-off valve has a valve element located at one of a first position and a second position. The first position disables supply of a hydraulic fluid to a frictional engagement mechanism of the automatic transmission. The second position enables supply of the hydraulic fluid to the frictional engagement mechanism. The line pressure detector is configured to detect a line pressure. The cut-off valve is to control a hydraulic fluid passage so that the line pressure is supplied to the line pressure detector in a case where the valve element is at the first position and so that the line pressure is not supplied to the line pressure detector in a case where the valve element is at the second position.

Hydraulic control device for automatic transmission

In case of power supply loss, a parking lock is operated by moving a piston of a hydraulic actuator rightward by use of hydraulic pressure accumulated in an accumulator. If a hydraulic pressure generating source becomes unable to generate line pressure due to its failure after the power supply loss, it is desirable that the parking lock be releasable to tow a vehicle, for example. In that time, because the hydraulic pressure in the accumulator has got out via an orifice, the parking lock can be released by moving the piston in the hydraulic actuator leftward by use of a manual operation device without interruption by the hydraulic pressure accumulated in the accumulator. Because the hydraulic pressure in the accumulator is automatically released via the orifice, a complicated mechanism for enabling the manual operation device to work without interference from the hydraulic actuator becomes unnecessary.

Parking lock device for transmission

In a hydraulic pressure supplying device for a transmission including a first oil pump adapted to be driven by a main shaft of the transmission, at least one second oil pump adapted to be driven by suitable means, and a check valve provided between the discharge side of the first oil pump and the discharge side of the second oil pump to prevent the flow of oil from the first oil pump to the second oil pump, a first filter is provided between the second oil pump and the check valve.

Hydraulic pressure supplying device for transmission

A choke valve for an automatic transmission is formed from a valve hole having a circular section that runs through a valve body in its thickness direction and a columnar valve main body that is fitted in the valve hole. The valve main body has a pair of annular channels formed on the outer periphery of the valve main body at opposite ends and a small diameter section formed between the two annular channels, the small diameter section together with the valve hole forming a choke. An inlet port and an outlet port formed between two separator plates and oil channels formed on opposite faces of the valve body communicate with the pair of annular channels, respectively. Thus, the structure of the choke valve for an automatic transmission is simplified, thereby reducing the cost.

Choke valve for automatic transmission

A control apparatus for a hydraulically-operated vehicular transmission, to buffer in-gear shocks in any driving condition of a vehicle, includes a pressure regulating solenoid valve for controlling an oil pressure in a hydraulic engaging element which establishes a predetermined speed transmission train of the hydraulically-operated vehicular transmission, an accumulator connected to an oil passage which is communicated with the hydraulic engaging element, a discriminator for discriminating whether the pressure accumulation in the accumulator-has been completed or not, and a controller for maintaining an outlet pressure of the pressure regulating solenoid valve at a predetermined pressure until the pressure accumulation in the accumulator has been completed and for increasing the output pressure of the pressure regulating solenoid valve, after the pressure accumulation in the accumulator has been completed, depending on a driving condition of the vehicle.

Control apparatus for hydraulically-operated vehicular transmission

Shift valves are provided to switch oil passage connections to a state in which an oil pressure in one hydraulic clutch of an arbitrary speed transmission train and an oil pressure in a hydraulic clutch of a transmission train which is adjacent thereto as seen in the order of speed are controllable by a pair of linear solenoid valves . Skipped speed change from a predetermined first speed transmission train to a second speed transmission train which is not adjacent to the first speed transmission train is made possible. In concrete, a large-capacity accumulator A is connected to an oil passage L which is in communication with 5th-speed hydraulic clutch C . At the time of skipped speed changing from 5th speed to 3rd speed, shift valves are switched to a state of 3rd-4th speed change. The oil pressures in the hydraulic clutches C , C for 3rd and 4th speed transmission trains, respectively, are made controllable by the linear solenoid valves . While buffering the pressure decrease of the oil pressure in the 5th-speed hydraulic clutch C by the accumulator A , pressure increase control of 3rd-speed clutch C is carried out by one of the linear solenoid valves to thereby skip-downshift from 5th to 3rd speed. The other linear solenoid valve is held at a low-pressure waiting state to prepare itself for the 3rd-4th speed switch-upshifting.

A changeover valve (13) connected to a shift valve unit (12) via four oil passages L3-L6, and two pressure regulating valves (14.sub.1, 14.sub.2) are provided. At speed changing when the changeover valve (13) is in a first (right) position, an off-going hydraulic clutch is connected to oil passage L3 to control its pressure drop by the pressure regulating valve (14.sub.1) and an on-coming hydraulic clutch is connected to L5 to control its pressure rise by the pressure regulating valve (14.sub.2). After completion of the speed changing, the changeover valve (13) is switched to a second (left) position. At speed changing when the changeover valve (13) is in the second position, an on-coming hydraulic clutch is connected to L4 to control its pressure rise by the pressure regulating valve (14.sub.1) and an off-going hydraulic clutch is connected to the L6 to control its pressure drop by the pressure regulating valve (14). After completion of the speed changing, the changeover valve (13) is switched to the first position. After completion of the speed changing, oil at line pressure is supplied to the on-coming hydraulic clutch from the line pressure oil passage L2 without passing through the pressure regulating valves, and oil is discharged from the off-going hydraulic clutch without passing through the pressure regulating valves.

Control apparatus for hydraulically operated vehicular transmission

A hydraulic control circuit for a hydraulically operated vehicular transmission has at least five forward transmission trains. The hydraulic control circuit is made up of three sets of first through third solenoid valves and three sets of first through third shift valves to be controlled for changeover by the three sets of solenoid valves such that each of the transmission trains is established by changeover combinations of each of the shift valves. The first shift valve controls a condition of communication between an oil supply passage which is in communication with a hydraulic oil pressure source and a first oil passage and a second oil passage which are both on a downstream side of the oil supply passage. The second shift valve controls a condition of communication between the first oil passage and a third oil passage which is on a downstream side of the first oil passage and also controls a condition of communication between the second oil passage and a fourth oil passage and a fifth oil passage which are both on a downstream side of the second oil passage. The third shift valve controls a condition of communication between the fifth oil passage and a sixth oil passage and a seventh oil passage which are both on a downstream side of the fifth oil passage.

Hydraulic control circuit for hydraulically operated vehicular

An apparatus for controlling an oil pressure for a vehicular automatic transmission has an accumulator connected to an oil passage which is in communication with each of clutches for transmission or speed changing; a regulator valve for regulating an oil pressure to be supplied to the hydraulic clutches; a first pressure control valve of electromagnetic type for controlling an output oil pressure of the regulator valve by causing an oil pressure to act thereupon; and a second pressure control valve of electromagnetic type for controlling a back pressure of the accumulator. A drain port of one of the first and second pressure control valves is connected to an oil passage on an output side of the other of the pressure control valves.

Fail-safe solenoid valve apparatus for controlling oil pressure for

An oil ejection control valve is interposed in a first hydraulic engagement element of an automatic transmission system from which oil is ejected when a certain speed stage shifting operation is to be carried out. The oil ejection control valve is provided with a valve member which is normally biased to a closed position by a spring. The valve member is provided with a first pressure receiving surface to which the ejection pressure from the first hydraulic engagement element is applied and a second pressure receiving surface to which the supply pressure to a second hydraulic engagement element is applied during the afore-mentioned shifting operation, the second hydraulic engagement element being the one to which pressure is supplied so as to engage the same during the speed stage shifting operation. Since the ejection pressure can favorably contribute to the reduction in the engagement pressure of the first hydraulic engagement element that is about to be disengaged without waiting for the engagement pressure for the second hydraulic engagement element to be engaged to build up, a smooth shifting operation is made possible either in an upshift operation or a downshift operation, and a transmission shock can be avoided at all time.

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Wako, Japan

Tetsuya Mochizuki