Method and circuit for actively cleaning electrohydraulic valves in a hydraulic control valve circuit

• US 6,170,506 B1
• Filed: 02/08/1999
• Issued: 01/09/2001
• Est. Priority Date: 02/08/1999
• Status: Expired due to Fees

• Current Assignee: Steve Regan
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Monaghan, Michael J., Butwin, John, Wickler, Wolfgang, Protopapas, Maria Eugenia, Cicala, Stephen Michael, Haase, Robert Cary
• Primary Examiner(s): Walton, George L.
• Application Number:
  US09/246,519
• Time in Patent Office: 701 Days
• Field of Search: 137/238, 137/240, 137/2, 137/15.01, 137/15.04, 137/15.05, 137/15.06, 251/129.05, 251/129.08, 318/632, 318/701, 361/139, 361/143, 361/146
• US Class Current: 137/2
• CPC Class Codes: F01L 2001/34443 Cleaning control of oil control valves
• CPC Class Codes: F16H 2061/1264 Hydraulic parts of the controller, e.g. a sticking valve or clogged channel
• CPC Class Codes: F16K 31/0675 Electromagnet aspects, e.g. electric supply therefor
• CPC Class Codes: G05D 16/2013 using throttling means as controlling means
• CPC Class Codes: Y10T 137/0324 With control of flow by a condition or characteristic of a fluid
• CPC Class Codes: Y10T 137/043 Valve or valve seat cleaning
• CPC Class Codes: Y10T 137/4245 Cleaning or steam sterilizing

Abstract

A method for cleaning a solenoid-operated regulator valve wherein command current applied to a solenoid actuator establishes a defined response of a valve. Cleaning current pulses applied to the solenoid establish a response that does not interfere with the effectiveness of the valve function. The pulse width, pulse amplitude, pulse direction and pulse period are determined by the degree of contamination of the valve environment.

Claims

1. A method for cleaning an electrohydraulic regulator valve in a control circuit having pressure operated control elements, the valve operating in contaminated fluid, applying a command current to the regulator valve to effect a controlled response of the control elements as determined by a given transfer function for the regulator valve;

applying at least one current pulse to the command current and establishing the pulse direction;

controlling the pulse width to effect an instantaneous response of the valve without adversely affecting the regulating function of the pressure applied to the control elements; and

controlling the amplitude of the pulse whereby the control capacity of the control elements is not adversely affected;

the pulse width and amplitude being empirically determined during calibration from transfer function results that indicate robust performance whereby contaminants are passed through the valve due to fluid flow through the valve to effect a predictable mechanical response of the valve to changes in command current, the calibration being in accordance with a predetermined level of contamination of the fluid.

2. The method set forth in claim 1 wherein successive current pulses are applied to the command current;

and

controlling the pulse period in accordance with the degree of contamination of the fluid.

3. The method set forth in claim 1 wherein pulse width, pulse direction and pulse amplitude are controlled as a function of the degree of contamination of the fluid.

4. The method set forth in claim 2 wherein pulse width, pulse direction and pulse amplitude are controlled in accordance with the degree of contamination of the fluid.

5. A cleaning cycle driver circuit for an electrohydraulic regulator valve in a control valve system having pressure-operated control elements, the regulator valve having a solenoid actuator for controlling hydraulic fluid flow therethrough;

a source of electric current for the driver circuit for effecting a controlled response of the regulator valve as determined by a given transfer function;

a current pulse generator subcircuit connected to the current source;

a pulse direction control subcircuit connected to the current source;

a pulse width control subcircuit and a pulse period control;

the pulse width, amplitude, direction and period being empirically determined during calibration from transfer function results that indicate robust performance, said calibration being in accordance with a predetermined level of contamination of the fluid;

a timing circuit connected to the pulse width control and the pulse period control, the timing circuit means responding to output signal values of the pulse period control and the pulse width control to connect and disconnect alternately the current source and the solenoid actuator;

the current pulse applied to the commanded current for the solenoid actuator effecting a controlled response of the regulator valve whereby frictional resistance to movement of the regulator due to the hydraulic contamination is overcome as hydraulic fluid flows through the regulator valve.

6. The driver circuit as set forth in claim 5 wherein the driver circuit includes a processor portion including means for determining pulse width, pulse amplitude and direction and pulse period in accordance with empirical data indicating the degree of contamination for hydraulic fluid used in the valve system.