Soft start clutch controller
AssigneeSenDEC Corporation
InventorSean O. Harnett
Life of this patent
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Abstract
A clutch actuator for an electromechanical clutch having a solenoid actuating coil initially provides power to the solenoid at a high rate by using a high duty cycle pulse with a modulated controller. When the initial engagement of the clutch elements is sensed by a decrease in current, the duty cycle of the pulse width modulator is reduced and thereafter increased in a controlled fashion to accomplish a soft start.
Claims21
A controller for operating a range of electrically operated solenoid actuated clutches requiring different operating current comprising:
- a controllable power source coupled to the solenoid;
- a current sensor coupled to the solenoid, responsive to the current flowing in the solenoid and producing an output signal proportional to said current at one of a predetermined time during the initial increase in current following activation of the solenoid and following saturation of the solenoid coil;
- a controller having a memory and coupled to the power source and the memory and responsive to the output signal for calculating a normalization factor based on the output signal and storing the normalization factor in the memory, increasing the current at a first rate, reducing the current to a second preselected current determined with reference to the normalization factor, increasing the current to a third preselected current based on the normalization factor at a second rate lower than the first rate, and then increasing the current at the first rate.
A controller for operating an electrically operated solenoid actuated clutch to provide controlled engagement comprising:
- a controllable power source coupled to a clutch solenoid;
- a current sensor coupled to the solenoid, responsive to the current flowing in the solenoid and producing an output signal proportional to said current
- a controller coupled to the power source and the current sensor for increasing the current at a first rate until the onset of pull-in, determined with reference to the rate of change of current with respect to time, reducing the current and then, increasing the current at a second rate lower than the first rate, and then increasing the current at the first rate.
A method for smoothly engaging a solenoid actuated electromechanical clutch comprising:
- applying current to the solenoid;
- detecting the onset of pull-in
- reducing the amount of current supplied to the solenoid;
- monitoring the load on the clutch;
- applying current to the solenoid to maintain a predetermined load profile as determined by the measured load.
A method for smoothly engaging a solenoid actuated electromechanical clutch comprising:
- applying current to the solenoid at a first rate;
- monitoring the current flowing through the solenoid;
- detecting the onset of pull-in;
- allowing a predetermined time to pass and then
- momentarily interrupting the flow of current to the solenoid;
- supplying current to the solenoid at a rate lower than the first rate.
A method for smoothly engaging a solenoid actuated electromechanical clutch having a solenoid and a solenoid core comprising:
- supplying current to the solenoid at a first rate;
- detecting the onset of pull-in;
- in response to the detecting, reducing the current supplied to the solenoid to a rate that causes a gradual engagement of the clutch.
Dependencies are inferred from the claim text.