Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Hitachi Automotive Eng. Co., Ltd.

Hitachi Automotive Engineering, Ltd.

Tomoo Ito

Hiroshi Kamifuji

Torazo Nishimiya

Tomiya Itakura

Haruhiko Kobayashi

Yuki Ejiri

Chiaki Niida

Takashi Iseyama

Yuuki Ejiri

Koichiro Yamada

Hisato Tsuruta

Katsuzi Murao

Tohoru Ozawa

Tadao Uchida

Yoshiro Kabakura

Yutaka Fujitsugu

A flow rate control system for controlling the idling rpm of an engine of a vehicle to a predetermined level in accordance with the temperature of cooling water or outdoor air, so as to eliminate hunting occurring in the flow rate of air supplied to the engine at engine startup the system includes a first valve seat, adapted to come into and out of engagement with a first valve body of a flow rate control valve assembly, and an annular protrusion located on a portion of an inner peripheral surface on an inlet side of the first valve seat. A conical surface portion is located downstream of the annular protrusion on an outlet side of the inner peripheral surface and divergingly tapers in a direction toward a downstream side of the first valve seat.

Flow rate control system

Automotive engine idle speed control device meters the flow rate of air supplied to the engine bypassing an intake pipe thereof during engine idle operation to thereby control the engine idle speed. An actuating vacuum is produced in accordance with an electrical signal and acts on a diaphragm fixed to a valve movable with the diaphragm to meter the bypass air flow. To cancel any external force acting on the valve, adjusting means is provided to control the vacuum on the diaphragm independently of the electrical signal to displace the diaphragm in a direction opposite to the direction of action of the external force on the valve.

Automotive engine idle speed control device

A throttle valve control device for an internal combustion engine controls an opening degree of a throttle valve by electrically drivingly rotating a rotary shaft, to which fixed is the throttle valve, in response to an angular movement of a speed acceleration pedal. The control device is actuated only in case of emergency. The control device is provided with a throttle valve returning mechanism for imparting a torque to cause the rotary shaft to rotate in a direction in which the throttle valve is fully closed. '

Throttle valve control device for internal combustion engines

A throttle valve is supported rotatably on a pipeline. The throttle valve is driven by a motor. A downstream side of the throttle valve is connected to an engine. A means for opening the throttle valve forcedly is provided so as not to allow a tar component in the fuel for driving the engine to stick on the throttle valve at an outer peripheral portion when the engine is shut down.

Automatic control apparatus for engine throttle valve

A hydraulic control solenoid valve comprising a plunger provided in a coil case and a shaft freely shiftable in a body. The shaft is provided with a first spool valve and a second spool valve. A feedback chamber is provided in the body and on the side of the first spool valve. A round shaped thin plate is fixed to the end of the first spool valve and positioned in the feedback chamber so as to form a constricted part of a flow passage formed between an interior wall of the feedback chamber and a peripheral surface of the thin plate. The cross-sectional area (S.sub.2) of the constricted part is not greater than 0.04 of the side surface area (S.sub.1) of the thin plate. The thin plate adds the damping coefficient (C.sub.d) and also functions as the stabilization of the behavior of the spool valves. The thin plate facilitates the prevention of the resonance phenomenon of the spool valves.

Closed loop type proportional electromagnetic valve for hydraulic control

A torque motor including a housing, a shaft member extending through the housing and supported by bearings, a stationary core in the housing and at least one coil fixed to the shaft member and arranged for rotation with respect to the stationary core within a finite range. Magnets are fixed to the housing for imparting rotational force to the coil and support members are provided in the housing for fixedly supporting the stationary core. The coil is provided with oppositely disposed free ends and extends across the stationary core between the free ends such that each of the free ends projects beyond an outer peripheral surface of the stationary core without contacting the stationary core. The support members include at least two plate members on opposite sides of the shaft member, the magnets being within the housing at portions other than where the support members are disposed.

Torque motor having a coil with finite turning range

An idle speed control device has an electromagnetic driving portion and a flow rate controlling portion disposed in a bypass passage formed in a throttle chamber such as to bypass a throttle valve. The flow rate controlling portion has a body defining a passage for the fluid to be controlled, a seal formed in an intermediate portion of the passage, a first valve driven by the plunger of the electromagnetic driving portion through a rod such as to be brought into and out of contact with the seat, a sleeve disposed in the body, and a second valve connected through a rod to the downstream side of the first valve such as to produce a vacuum force which acts in the opposite direction to the vacuum force produced on the first valve thereby to absorb any fluctuation in the intake pressure in cooperation with the first valve, the second valve being loosely received by the sleeve. According to this arrangement, it is possible to eliminate any unfavorable effect of the fluctuation in the intake vacuum on the actual air flow rate. In addition, since the flow from the vacuum compensating portion is minimized, the vacuum compensation is made possible without incurring any increase in the initial leak.

Idle speed control device

An apparatus for controlling an opening degree of a throttle valve comprises a motor including a rotor, a detector for detecting the opening degree of the throttle valve, and a control unit for outputting a command to the motor so as to swing the throttle valve to the desired opening degree which is determined by the control unit in accordance with the information representing the engine condition. The apparatus further comprises a one-piece shaft which includes a throttle valve shaft and an output shaft of the rotor of the motor.

Throttle valve controlling apparatus

An engine control apparatus having a microcomputer which controls an operating condition modifying means to modify the operating condition of the engine, wherein the absolute value .DELTA.C of the difference, C.sub.now -C.sub.old is calculated from a previously obtained basic amount of control C.sub.old, and a newly obtained basic amount of control C.sub.now, a correction coefficient K is determined which takes a value of 1 to nearly 0 as the .DELTA.C is increased, and then the C.sub.set of

Engine control apparatus and control method

In a rotational speed control apparatus for an internal combustion engine in which a signal-responsive diaphragm, whose controlling position is determined by a controlled negative pressure signal, is provided with a valve member controlling to negative pressure acting upon a driving diaphragm controlling the opening of a throttle valve, the negative pressure acting upon the driving diaphragm, when the controlled negative pressure signal is detected to be not normal, is controlled to be shifted to the level at which the driving diaphragm is rendered substantially non-operable.

Rotational speed control apparatus for internal combustion engines

A fuel supplying system used in engine starting includes throttle valve means disposed in an intake air passage and metering valve means disposed in a fuel passage which extends from a fuel reservoir to a space of the intake air passage downstream from the throttle valve means. In order to obtain a required air-fuel ratio of a mixture determined in accordance with data representing states of an engine, in the fuel supplying system an opening degree of the throttle valve means which have a response delay is held constant and an opening degree of the metering valve means is adapted to be changed in accordance with a change of the required air-fuel ratio.

Air-fuel ratio control system for engine starting

An apparatus for enriching an air-fuel mixture supplied by a carburetor upon starting operation of an internal combustion engine comprises a fuel quantity increasing passage which is operative independent of main fuel supply system. The passage has an inlet communicated to a fuel supply source and an outlet opened at a location downstream of a throttle valve. The amount of fuel ejected from the outlet of the passage is controlled by a control signal which represents a product of a value variable in dependence on a suction vacuum, the rotational frequency of the engine and a value variable in dependence on the temperature of engine cooling water.

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Katsuta, Japan

Tomoo Ito