×

Vehicle engine idle speed governor with unsymmetric correction rates

  • US 4,245,599 A
  • Filed: 12/19/1979
  • Issued: 01/20/1981
  • Est. Priority Date: 12/19/1979
  • Status: Expired due to Term
First Claim
Patent Images

1. In a vehicle engine having fuel induction and control means including a throttle for controlling the air flow rate to the engine and a throttle stop for determining the engine idle throttle position, engine idle speed governing apparatus comprising:

  • actuator means effective to position the throttle stop in response to an actuator command signal, said actuator means being capable of movement, at least in the direction of decreasing engine speed, at a faster rate than the engine itself can decrease its speed;

    means effective to generate a speed error signal having an absolute value proportional to the difference between engine speed and a predetermined reference and a further characteristic indicative of high or low speed, respectively, for speeds greater than the reference or speeds less than the reference;

    memory means effective to store predetermined actuator command signals corresponding to individual high and low speed error signals, the actuator command signals corresponding to at least the largest low speed error signals having values effective to produce a greater throttle stop movement than the actuator command signals corresponding to the high speed error signals of the same absolute value;

    means effective to obtain from the memory means the actuator command signal corresponding to the speed error signal and to provide the actuator command signal to the actuator means to generate a throttle stop movement to return engine idle speed toward the reference by an amount determined at least in part by the value of the actuator command signal, whereby at least large corrective throttle stop movement is smaller in the correction of high engine idle speed than in the correction of low engine idle speed to prevent excessive overshoot while decreasing engine speed with the consequent possibility of engine stall.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×