Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Mitsubishi Denki Kabushiki Kaisha

Kabushiki Kaisha Daikin Seisakusho

Mikuni Kogyo Kabushiki Kaisha

Bonnosuke Takamiya

Takeo Hiramatsu

Yoshimasa Nagayoshi

Takeo Shimizu

Yuichi Tanaka

Hiroshi Fukuchi

Takashi Ishida

Hirokazu Nakamura

Yutaka Tsukamoto

Takao Miki

Kiyoshi Shikata

Katuhiro Hatta

In an automatic transmission gear system which selectively actuates a plurality of frictional elements by oil pressure such as clutches and brakes that are provided in the transmission gear system in order to obtain different gear ratios, one frictional element is disengaged concurrently with engaging of another frictional element for switching the gear ratio (speed change). At that time, it is important to adjust the timing for actuating the frictional elements depending on the conditions of the engine and the vehicle itself. The present invention relates to a control device for an automatic transmission gear system which assures smooth gear shifting at all times by adequately controlling the overlap of the torque capacities of the frictional elements.

Control device for automatic transmission gear system

A method of controlling the hydraulic pressure for an automatic transmission gear system, in which the actual rotation speed of a rotatable element during a speed shift from, for example, the 1st speed ratio to the 2nd speed ratio is detected, and the hydraulic pressure supplied to a frictional engaging element acting to change the rotation speed of the rotatable element is controlled so that the rate of change of the rotation speed of the rotatable element can converge to a predetermined change rate when the speed change rate due to the speed shift is ideal. On the other basis of the hydraulic pressure supplied to the frictional engaging element in the final state of the speed shift, the initial hydraulic pressure to be supplied to the frictional engaging element immediately after starting of the next speed shift is computed. Such a trial is repeated a plurality of times so that an automatic transmission whose operating hydraulic pressure is not primarily designed to meet the operation of an engine from the aspect of the capacity can be adapted to operate with the engine.

Method of controlling hydraulic pressure for an automatic transmission

In an automatic transmission for a vehicle in which frictional engaging elements are selectively actuated by application of a hydraulic pressure for stopping the rotation of a selected one of rotary elements relative to the others thereby changing over the speed ratio, and the hydraulic pressure is subjected to feedback control so that an actual changing rate of the rotation speed of the rotary element can follow up a predetermined reference rate for attaining an ideal speed shift, an initial hydraulic pressure to be supplied to a specific frictional engaging element in the starting stage of a succeeding speed shift is decided on the basis of the detected value of the hydraulic pressure supplied to the specific frictional engaging element in a preceding speed shift. Thus, even when the capacity of the automatic transmission does not primarily match that of an engine combined therewith, the initial hydraulic pressure supplied to the frictional engaging element can be quickly converged to an appropriate value with high accuracy, and the automatic transmission can be satisfactorily combined with any one of engines having different capacities.

A power transmission includes two piston-type actuators for selectively engaging and releasing their associated clutches. Each of the actuators is designed in such a way that in order to compensate a centrifugal hydraulic pressure to be developed in a working fluid chamber by a remaining hydraulic fluid upon release of the clutch, a centrifugal hydraulic pressure chamber is formed on the side opposite to the working fluid chamber relative to a piston and a centrifugal hydraulic pressure equal to the centrifugal hydraulic pressure in the working fluid chamber is produced in the centrifugal hydraulic pressure chamber. A partition forming the centrifugal hydraulic pressure chamber also serves as a cylinder forming the working fluid chamber of the other actuator.

Power transmission

A differential limiting device is provided for use in a differential mechanism adapted to divide and transmit a torque from an input shaft to two output shafts. The device includes an oil pump driven by the difference in revolution speed between two shafts selected from the input shaft and output shafts, a wet clutch equipped with two types of disks and adapted to connect said selected two shafts to each other by the pressure of a working oil discharged from the oil pump, and an orifice-equipped lubricating passage for jetting out the working oil, which has been discharged from the oil pump, toward the disks of the clutch in order to avoid possible burnout of the disks.

Differential speed limiting device mechanism

A differential capable of distributing a torque of the input shaft to the two output shaft thereof and equipped with a differential motion limiting mechanism. The differential comprises a differential mechanism which receives a driving force through the input shaft thereof from a transmission connected to an engine and distributes the driving force to two output shafts; an oil pump interposed between two shafts, namely, the input shaft and either one of the output shafts themselves, and adapted to be driven by a differential revolving speed between the two shafts so as to produce a discharge pressure corresponding to the differential revolving speed; a clutch mechanism for coupling the two shafts; a hydraulic circuit for supplying the discharge pressure of the oil pump to the clutch mechanism to engage the two shafts; and hydraulic control means provided in the hydraulic circuit to control the discharge pressure to be supplied to the clutch mechanism. The differential produces a limiting torque corresponding to the differential revolving speed between the two shafts to limit the differential motion between the two shafts.

Differential with differential motion limiting mechanism

The present invention relates to a power transmission system for a vehicle of the type in which front and rear wheels are driven by a sole engine. In order to control the distribution of drive torque produced by the engine to front wheel side and rear wheel side of the vehicle according to a difference in rotational speed between both sides and in relative rotational direction between both sides, the power transmission system includes an oil pump adapted to be driven by a first rotational shaft which transmits a driving torque from an engine to front wheels of the vehicle and a second rotational shaft which transmits the driving force to rear wheels of the vehicle. The oil pump produces an oil pressure proportional to the difference in rotational speed and has at least two ports. A clutch mechanism couples the rotational shafts with each other by the discharge pressure of the oil pump and, the clutch mechanism is disposed between the rotational shafts. An oil pressure control system controls the discharge pressure fed from the oil pump to the clutch mechanism to adjust the coupling force of the clutch mechanism in accordance with the difference in the relative rotational direction between the pair of rotational shafts.

Power transmission system for vehicle

In a continuously variable transmission apparatus for a vehicle having a slip type clutch disposed between a drive shaft of an engine and an input shaft of a continuously variable transmission mechanism, a torque detecting device to detect torque of the engine, an engine speed detecting device to detect rotational speed of the engine, an output shaft speed detecting device to detect rotational speed of an output shaft of the slip type clutch, a vehicle speed detecting device to detect running speed of the vehicle, and an electronic control device to control the continuously variable transmission mechanism and the slip type clutch according to signals from the detecting devices are provided. The slip type clutch control device is controlled to give a reference amount of slip determined according to driving condition of the vehicle, and speed ratio of the continuously variable transmission mechanism is controlled to a value determined primarily on the basis of control signal of the slip type clutch.

Continuously variable transmission apparatus for automobile

A fully automatic transmission for use in automobiles requires the use of only a single manually operable switch in the vehicle compartment for selecting the travelling direction. All other functions of the transmission, namely the selection of the speed range, including neutral and the application of a parking mechanism are performed by a hydraulc control system in combination with an electronic control system operating according to a predetermined process.

Vehicular automatic speed change gear assembly

An automatic vehicle transmission is operated simply by driver selection of a forward or backward switch, utilizing an electric and hydraulic control system to effect speed changes among the various forward speeds, neutral and park. Also, during a shift, a solenoid valve is used to temporarily lower the pressure to prevent undue shift shock.

Automatic transmission for vehicles

A fuel supplying device for an internal combustion engine having a fuel supply passage (4) for introducing fuel fed from a fuel pump (2) at a substantially constant pressure to a fuel injector (9) operative at a predetermined constant pressure. The fuel injector is installed at a congregated portion (7) of engine intake manifolds (8). A metering valve (11) includes a motor (13) so that drop is maintained substantially constant by a differential regulator (12). The metering valve is disposed in an intermediate portion of the fuel supply passage. Calculating means (15) including a servo signal generator (18) calculates an injection flow amount causing a predetermined air/fuel ratio on the basis of signals of various engine running factors. An operational signal output from the servo signal generating circuit of the calculating means is applied to the drive motor means for driving said metering valve to thereby inject fuel into the intake manifolds.

Fuel supplying device for internal combustion engine

An air-fuel ratio regulator for internal combustion engine, used mainly in the intake system of an automotive engine, comprising an air passage leading from the intake passage or the atmosphere upstream of the throttle valve in the carburetor to the intake passage downstream of the throttle valve, a control valve for opening and closing the air passage, and differential-pressure responsive means for actuating the control valve. The differential-pressure responsive means, consisting of a pair of vacuum chambers on either side of a diaphragm, opens the control valve during the high-speed operation or in rapid deceleration where the intake manifold vacuum generated downstream of the throttle valve increases rapidly, in order to prevent the intake air-fuel mixture from becoming rich, and to maintain the air-fuel ratio appropriately.

Air-fuel ratio regulator for internal combustion engine

A gas injection system for an internal combustion engine including a combustion chamber having an inlet port connected to a main intake passage in which a throttle valve is mounted, and an injection bore provided on the combustion chamber and connected to one end of a secondary intake passage which is opened and closed by a secondary inlet valve, said system comprising a port provided in a wall of said main intake passage upstream of the throttle valve and connected to the other end of the secondary intake passage, through which air or an air-fuel mixture is led and strongly injected from said injection bore by a high negative pressure produced in the combustion chamber, and another port provided in the wall of said main intake passage slightly downstream of the throttle valve at its idle-open position, an amount of said injected gas being controlled by a negative pressure produced at said another port.

Gas injection system for internal combustion engine

An automotive multicylinder internal combustion engine is liable to emit noxious gases under medium and low load conditions. Such air-polluting emissions as hydrocarbons, carbon monoxide and oxides of nitrogen are effectively reduced by supplying a rich mixture with air-fuel ratio of approximately 12 to 14 to a group of its cylinders, and a lean mixture with air-fuel ratio of approximately 17 to 20 to the remaining cylinders. While under high load conditions, substantially the same mixture with air-fuel ratio of approximately 13 to 15 is supplied to all the cylinders to prevent a drop in engine output and improve fuel economy.

Growing community of inventors

Kyoto, Japan

Bonnosuke Takamiya