Abstract: A control unit has an electronic control device that includes a base board on which a plurality of elements, including a microcomputer containing an automatic transmission program, are disposed. The electronic control device includes an integral neutral start switch connected to the microcomputer. The neutral start switch also includes a rotor and contact-type switches operated by rotation-of the rotor. The base board and the rotor are disposed in a case and are substantially parallel to each other at opposite sides of an intermediate wall formed in the case. The base board is separated from the contact-type switches by the intermediate wall to prevent communication of oil or metal dust from the contact-type switches to the base board.

Abstract: A compact-sized position detecting switch-combined electronic control unit disposed on the main body of an automatic transmission and used for detecting range positions chosen by a driver during a shifting operation. The control unit has a base board on which a plurality of elements are arranged, including a microcomputer containing an automatic transmission control program, and a position detecting switch whose detecting portion is connected to the microcomputer. The base board and the position detecting switch are disposed in a single case. The position detecting switch has a rotor and a plurality of non-contact sensors disposed on the base board. The microcomputer contains a learning control program for calculating and correcting any positional deviation in the rotational angle of the rotor with respect to each sensor on the basis of signals from the sensors corresponding to rotation of the rotor. Some of the elements on the base board are arranged outside the range of rotation of the rotor.

Abstract: In a position detecting switch, a first movable contact is disposed in a first receptacle formed in a sliding body and is urged toward a casing member by a first spring so as to engage first and second stationary contacts mounted in the casing member when the sliding body is in a selected position. In order to prevent non-contact due to rotating moment of the first movable contact relative to the stationary contacts one or more features for inhibiting or reducing the relative moment are provided such as: (1) The first and second stationary contacts can be urged toward the first movable contact by fourth and fifth springs. (2) An elastic member or members can be disposed in a clearance between end walls of the sliding body and walls of the first receptacle. (3) The first spring can be restrained to apply its load to a substantially middle portion of the movable contact. (4) A plurality of the first springs can be provided to apply load the movable contact at a plurality of locations in a lengthwise direction.

Abstract: A pressure regulating valve in a hydraulic control system for an automatic transmission according including a pressure regulating unit having a spool made slidable in a valve sleeve 10. An electromagnetic unit for causing a hollow core (or stator) is provided to attract a plunger (or movable element) arranged on a push rod communicating with the spool. The spool is moved by a spool moving mechanism in a direction to increase the flow from an input port to an output port to thereby raise an output pressure from an output port when the output pressure is lowered by a leakage. The spool position is controlled to control the output pressure in accordance with a balance among a spring force of spring means fitted in the valve sleeve, a feedback force resulting from the output pressure, and an electromagnetic attraction to be established in response to an electric signal provided to the electromagnetic unit having the hollow core and the plunger.

Abstract: An electromagnetic pressure regulating valve includes a hollow core, a coil surrounding the core and a plunger for applying a load to a valve member through a shaft fitted in the hollow of the core, so that the pressure regulating valve is actuated when an electric signal is fed to the coil. A bushing is mounted in the hollow portion of the core for supporting the shaft for sliding relative to the core and is made of a resin material on at least its sliding face contacting the shaft. An oil passage is provided in the valve for circulating a lubricant to lubricate the areas of sliding contact between the bushing and the shaft.

Abstract: An electromagnetic valve includes a hydraulic circuit coupling having an input port and a strainer mounted over the input port. The strainer is an entirely planar member and includes a filter portion having a plurality of pores forming a mesh and a retaining portion formed around the outer circumference of the filter portion. The strainer is fixed on the cylindrical wall of the input port of the hydraulic circuit coupling. The hydraulic circuit coupling may have a plurality of projections for engaging and holding the strainer. Alternatively, the retaining portion of the strainer may have a plurality of coplanar projections extending from its outer circumference coplanar with the filter portion and mating with a groove formed around the inner circumference of the input port of the coupling.

Abstract: An automatic transmission includes a casing housing a transmission mechanism and having a wall with a through-hole. A first plurality of electronic components is mounted exterior to the casing and a second plurality of electronic components is mounted on the interior of the casing. A sealed wire terminal is mounted in and closes the through-hole 21. An electronic control unit is mounted in the sealed wire terminal 22 and cables electrically connect the electronic control unit to the first and second pluralities of electronic components. The sealed wire terminal includes a seal member supporting the cables and sealing the through-hole. Thus, the automatic transmission and the electronic control unit can be combined before mounting on a vehicle.

Abstract: An electronic control unit (ECU) and a position detection unit are disposed in separate chambers formed in a case. Two switch portions are separately disposed on opposite sides of a movable member of the position detection unit, thus reducing the size of the unit. The signal-related circuit that needs to be connected to the ECU for signal transmission and the drive circuit, for starting the starter motor and turning on the reverse lamps, that does not need the connection to the ECU for signal transmission, are separately disposed on the opposite sides of the movable member, that is, on the case side and a first cover side. The drive circuit is completely separated from the signal-related circuit and the ECU, thus preventing the drive circuit from electrically interfering with the signal-related circuit or the ECU.

Abstract: A pressure regulating valve includes a valve body with an input port, an output port and a drain port. A valve member is slidably arranged in the valve body for controlling the fluid communication among the ports and is positioned by an electromagnetic solenoid and a spring, both of which apply loads to the valve member. A spring load setting mechanism is used to move the valve member to a position at which a load according to an input signal to the electromagnetic solenoid, the load of the spring and a feedback pressure are balanced. A supply pressure fed to the input port is thereby regulated and output from the output port. The load setting mechanism includes a receiving plug screwed into the valve body for holding and supporting the spring in a compressed state and a retainer fixed on the valve body for holding the receiving plug against rotation. The receiving plug has an indexed portion at its distal end which is engaged by the restrainer for establishing a rotational position.

Abstract: A torque detecting device includes a first rotary member connected to an input shaft and a second rotary member connected to an output shaft and arranged coaxially with the first rotary member. An elastic member is sandwiched between the first rotary member and the second rotary member and deforms according to the torque acting thereon. A sensor is arranged confronting the first and second rotary members to detect their rotational phases and a torque computer computes the torque by determining the rotational phase difference between the first and second rotary members from the rotational phases as detected by the sensor.

Abstract: A slotted rotor is fixed to a manual shaft operatable by using a shift lever. The slotted rotor is turnable in a restricted angle about the manual shaft. The rotor has a slot in arc segment a, slots in arc segment b, slots in arc segment c, slots in arc segment d, and slots in arc segment e that are arranged concentrically about the manual shaft, in that order starting from the manual shaft. As the rotor turns, the slots in arc segments d, e cause incremental pulses to be generated. Based on the number of pulses, a control unit detects deviation from the planned neutral position and establishes a correct neutral position. The position detecting apparatus and method make it easy for a worker to perform the neutral position alignment of a neutral start switch and to maintain the alignment after the switch has been mounted.

Abstract: Seal rings are set in oil grooves which are situated at both sides of two oil passages communicating two hydraulic actuators which operate oppositely. First and second seal rings oil-tightly seal between the first oil passage and sleeve, while third and fourth seal rings oil-tightly seal between the second oil passage and the sleeve. Accordingly even if oil flows oppositely in each of two oil passages due to the opposing motions of the two contiguous hydraulic actuators, not oil leakage occurs. Furthermore, a draining groove is situated between the oil grooves in which the second and third seal rings are installed.

Abstract: Thrust force generated by a hydraulic actuator is absorbed in a attachment device for a four speed automatic transmission mechanism. When hydraulic pressure is applied to the hydraulic actuator to engage a third and a fourth clutches, pressing force from a piston works on a strut member situated between the third and fourth clutches as a compression force, while a force working on a drum member as a tension force, so that these forces are counterbalanced and absorbed in the attachment device. Consequently, one directional move of the attachment device is supported by a little force such as contacting a snap ring and a thrust washer to a clutch drum, on the other hand, another move of the attachment device is supported by a little force such as connecting the drum member and a big ring gear by a snap ring.

Abstract: A differential motion limiting device, for a power transmission device for four wheel drive vehicle, to regulate differential motion of a center differential device includes a wet-type multi plate clutch and an hydraulic actuator. And a switching valve is attached to an oil passage to the hydraulic actuator. In normal running condition, a switching valve is in connecting condition, and a hydraulic pressure being varied by driving conditions is applied to a hydraulic actuator. Under this condition, the clutch is slippingly engaged by certain engaging force so that torque, per certain ratio, is transmitted to the front and the rear wheels. In high speed condition, such as the maximum speed state like an overdrive, or a vehicle speed more than 100 km/h, sensors detect such state, then the switching valve is switched, and the clutch is released. As a result, lubrication oil is flowed between friction plates and separators of the clutch to release heat therefrom.

Abstract: A centrifugal hydraulic pressure cancel chamber is arranged at the back of a second piston member of a second hydraulic actuator for the second clutch. A first piston member of a first hydraulic actuator for a first clutch is situated behind the second piston. A centrifugal hydraulic pressure cancel plate is set at an inner periphery on a rotating member to prohibit axial movement and set at an outside periphery in a inside of the piston member oil-tightly. The inside surface of the second piston member and the cancel plate compose the centrifugal hydraulic pressure cancel chamber. A spring is placed between the second piston member and the cancel plate, and the centrifugal hydraulic cancel chamber and the spring work correspondingly to the first and the second piston members.

Abstract: A hydraulic control device which has a check valve controlling hydraulic pressure to a hydraulic actuator. Hydraulic pressure is selectively supplied to one of plural oil passages having different capacity orifices by a switching valve which switches high speed rotation mode and low speed rotation mode. A hydraulic power source and plural oil passages having different capacity orifices are connected to the switching valve which is controlled by hydraulic pressure varying according to vehicle speed. When rotation of the input shaft is low, the switching valve is connected to the oil passage having small capacity orifice, then hydraulic pressure is supplied to the hydraulic actuator through the orifice of small capacity. At this stage, as centrifugal force working on the ball in the check valve is low, the check valve is closed by even small amount of oil supply through the small capacity orifice, and raises hydraulic pressure in the actuator, so the clutch is engaged smoothly.

Abstract: A four-wheel drive vehicle having a front- and rear-wheel engaging mechanism designed to enable differential limiting means provided between the front and rear wheels to be controlled over the range from the direct coupling position to the disengaged position through the slip region by the control of the degree of engagement. The vehicle is provided with engaging means for driving the front- and rear-wheel engaging mechanism at a set degree of engagement, detecting means for detecting a running condition, and control means for setting a degree of engagement to control the engaging means. The control means has reference data concerning degrees of engagement respectively corresponding to various running conditions, and sets a degree of engagement selected from the reference data in accordance with the detected running condition. Thus, it is possible to engage the front- and rear-wheel engaging mechanism in such a manner as to prevent the occurrence of tight corner braking while avoiding slipping.

Abstract: A rotation detecting sensor is situated on the inside of a sleeve, so that the sensor detects a detected member, such as an input shaft and the like for an automatic transmission, from the inside of the sleeve. A hub projected toward inside a case is constituted, a sleeve enclosing the hub is fixed on the rotating shaft, the rotation detecting sensor is installed on the hub so that the sensor faces a detected member constituted on the inner surface of the sleeve. By this, the rotating shaft such as the input shaft and the like rotates with being supported by the hub of the case, and the sleeve fixed on the rotating shaft rotates together. The detected member is detected by the rotation detecting sensor placed at the hub.

Abstract: A power transmission device for four wheel drive vehicle includes a differential motion limiting device, for limiting differential motion of a center differential device, which is made up by a wet-type frictional clutch and a hydraulic actuator. Under running condition, the frictional clutch is engaged by certain engaging force, and considering frictional coefficient of roads, the clutch is engaged with some slips so that torque distribution to front and rear wheels becomes even (50:50), then torque is distributed from the center differential device to front and rear wheels. The line pressure is applied to the hydraulic actuator through a regulator valve. In normal running condition, the regulator valve reduces the line pressure pre certain ratio, the reduced pressure is applied to the hydraulic actuator. In the case the manual valve being shifted to R range or low speed position, the regulator valve is switched to apply the line pressure directly to the hydraulic actuator.

Abstract: An intake adapter is provided on an oil intake opening formed in a transaxle casing. A tightly sealed space in communication with an oil pump is provided in the lower part of the transaxle housing, formed in such a manner that it can be opened by the removal of a cover member which is secured to the transaxle casing in a freely mountable and removable manner. An oil strainer is housed in the tightly sealed space and an intake adapter is provided in communication with the tightly space and an oil sump. As a result the oil in the oil sump is taken into the intake opening of the oil strainer from the adapter, and foreign matter such as iron particles and the like is removed in a filter element and the filtered oil is supplied to an oil pump.