Engine control apparatus

• US 4,552,116 A
• Filed: 08/16/1984
• Issued: 11/12/1985
• Est. Priority Date: 08/26/1983
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kuroiwa, Hiroshi, Oyama, Yoshishige, Yamauchi, Teruo, Kirisawa, Tadashi
• Primary Examiner(s): Nelli, Raymond A.
• Application Number:
  US06/641,337
• Time in Patent Office: 453 Days
• Field of Search: 123/350, 123/478, 123/492, 123/493, 123/489, 123/440, 261/51, 261/50, 261/DIG. 19
• US Class Current: 123/399
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02D 41/1476 Biasing of the sensor
• CPC Class Codes: F02D 43/00 Conjoint electrical control of two or more functions, e.g. ignition, fuel-air mixture, recirculation, supercharging or exhaust-gas treatment

Abstract

An engine control apparatus of fuel supply preferential type in which the rate of fuel supply is controlled in accordance with the amount of operation of an accelerator pedal and the operation condition of the engine, and the opening of the throttle valve is controlled in accordance with a command opening which is determined by the rate of the fuel supply is disclosed. For ensuring a good air-fuel ratio control, the control apparatus comprises first closed loop control adapted to detect the throttle valve opening and to effect a control to make the throttle valve opening converge at the command opening and second closed loop control adapted to detect the air-flow ratio of the air-fuel mixture fed to the engine wth air-fuel ratio sensor which detects oxygen concentration in the exhaust gases from the engine and to effect a control to make the air-fuel ratio converge at a command air-fuel ratio.

Claims

1. In an engine control apparatus including means for controlling a rate of fuel supplied to an engine, means for controlling a rate of intake air drawn into the engine by changing an opening of a throttle valve actuated by a throttle actuator, an acceleration pedal position sensor means for detecting a position of an acceleration pedal operated by an operator and providing an output signal of the position of the acceleration pedal, further sensor means for detecting engine conditions and providing output signals of sensed engine conditions, said further sensor means including an engine temperature sensor and an engine rotational speed sensor, and a control circuit means for inputting output signals from said acceleration pedal position sensor means and said further sensor means for producing control signals for determining a rate of fuel supply in accordance with a position of said acceleration pedal, the engine conditions, and an opening of said throttle valve is controlled in accordance with a command opening determined in accordance with the rate of the fuel supply, the control apparatus comprising:

first closed loop control means for detecting the throttle valve opening and for effecting a control to make the throttle valve opening converge at said command opening, said first closed loop control means including a throttle opening sensor means for detecting an opening of said throttle valve, said control circuit means, and said throttle actuator, and

second closed loop control means for detecting the air-fuel ratio of the air-fuel mixture supplied to the engine and for effecting a control to make the air-fuel ratio converge at a command air-fuel ratio, said second closed loop means including an air-fuel ratio sensor means for detecting oxygen concentration in exhaust gas of the engine, said control circuit means, and said throttle actuator.

2. The engine control apparatus according to claim 1, wherein said air-fuel ratio means has a linear output characteristics.

3. The engine control apparatus according to claim 1, further comprising means for controlling said command opening in such a manner that a commencement of an operation for controlling the throttle valve opening is delayed in accordance with the engine conditions during at least one of an acceleration or deceleration of the engine.

4. The engine control apparatus according to claim 1, further comprising means for controlling said command opening in such a manner that a commencement of the operation for controlling the throttle valve opening is delayed in accordance with the engine conditions and a changing rate of said command signal is controlled in accordance with the engine conditions during at least one of an acceleration or deceleration of the engine.