Motor-driven throttle valve control device for internal combustion engine
AssigneeHitachi, Ltd.
InventorsYasuo Saito, Takahiro Shimura
Life of this patent
Estimating the term…
Abstract
A spring to ensure default opening is constituted by a single piano wire where a return spring with a larger coil diameter and a default spring with a smaller coil diameter are connected via a connection arm formed with a spring hook. The spring with a smaller coil diameter is inserted in the spring with a larger coil diameter thereby the springs are overlapped in an axial direction as a duplex-winding spring structure. Further, a magnetic sensor is provided in a position inside the both spring with a larger coil diameter and spring with a smaller coil diameter.
Claims10
A motor-driven throttle valve control device for an internal combustion engine comprising a throttle shaft, a throttle valve fixed to the throttle shaft, and a motor, wherein a torque of the motor is transmitted to the throttle shaft,
- the throttle valve control device further comprising:
- a default stopper provided at a specified opening position from a minimum opening position of the throttle valve;
- a default spring which exerting its spring force on the throttle shaft toward a default stopper position in a valve opening direction;
- and
- a return spring which acts independently of the default spring to exert its spring force on the throttle shaft in a valve closing direction between the default stopper position and a full open position of the throttle valve,
- wherein the default spring and the return spring have mutually different coil diameters and are integrated with each other by a double coil spring arrangement in which those springs are formed continuously in a length of spring wire and arranged with overlapped structure in an axial direction so that at least part of one spring with a smaller coil diameter is located inside another with a larger coil diameter.
A motor-driven throttle valve control device for an internal combustion engine, which operates a throttle valve for controlling an intake air flow rate in an internal combustion engine using an electric motor-driven actuator, and which has a default opening setting mechanism that keeps a predetermined throttle valve opening more than a full closed position (hereinbelow, this opening being defined as a default opening) when the electric motor-driven actuator is unenergized,
- the device comprising a return spring for exerting a spring force in a closing direction to the throttle valve, and a default spring for exerting a spring force to the default opening side from the full closed position of the throttle valve,
- wherein the coil diameter of the return spring is different from that of the default spring, and at least a part of one spring with a smaller coil diameter of them is located inside the other one of the springs with a larger coil diameter,
- wherein one end of the spring with a larger coil diameter is movably provided on a throttle shaft,
- one end of the spring with a smaller coil diameter is movably provided on the throttle shaft, and integrally connected to one end of the spring with a larger coil diameter, and
- the other end of one of the springs is fixed to an unrotatable fixing member while the other end of one of the springs is fixed to the rotatable throttle shaft.
Dependencies are inferred from the claim text.