Fluid metering valve

• US 10,203,704 B2
• Filed: 06/16/2017
• Issued: 02/12/2019
• Est. Priority Date: 06/16/2016
• Status: Active Grant

• Current Assignee: Moog Incorporated
• Original Assignee: Moog Incorporated
• Inventors: Weber, Gregory B.
• Primary Examiner(s): McCalister, William
• Application Number:
  US15/625,977
• Publication Number:
  US 20170364097A1
• Time in Patent Office: 606 Days
• Field of Search: 137485-4925
• CPC Class Codes: F15B 13/043 with electrically-controlled pilot valves
• CPC Class Codes: F15B 13/0438 the pilot valves being of the nozzle-flapper type
• CPC Class Codes: F15B 13/086 Sensing means, e.g. pressure sensors
• CPC Class Codes: F15B 19/002 Calibrating
• CPC Class Codes: F15B 19/005 Fault detection or monitoring
• CPC Class Codes: F15B 2013/0409 Position sensing or feedback of the valve member
• CPC Class Codes: F15B 21/087 Control strategy, e.g. with block diagram
• CPC Class Codes: F15B 2211/615 Filtering means
• CPC Class Codes: F15B 2211/6306 representing a pressure
• CPC Class Codes: F15B 2211/6309 the pressure being a pressure source supply pressure
• CPC Class Codes: F15B 2211/6316 the pressure being a pilot pressure
• CPC Class Codes: F15B 2211/634 representing a state of a valve
• CPC Class Codes: F15B 2211/6343 representing a temperature
• CPC Class Codes: F15B 2211/6654 Flow rate control
• CPC Class Codes: F15B 2211/6656 Closed loop control, i.e. control using feedback
• CPC Class Codes: F15B 2211/8609 the abnormal condition being cavitation
• CPC Class Codes: F16K 11/07 with cylindrical slides
• CPC Class Codes: F16K 31/002 actuated by temperature variation thermo-electric F16K31/025
• CPC Class Codes: F16K 31/02 electric F16K31/004 takes precedence; magnetic
• CPC Class Codes: F16K 37/0041 for measuring valve parameters F16K37/0033 takes precedence
• CPC Class Codes: F16K 37/005 : for measuring fluid parameters F16K37/0033 takes precedence
• CPC Class Codes: G05D 3/12 : using feedback
• CPC Class Codes: G05D 7/005 : characterised by the use of auxiliary non-electric power combined with the use of electric means
• CPC Class Codes: G05D 7/0623 : characterised by the set value given to the control element

Abstract

A servovalve system comprising a pilot stage valve in communication with an hydraulic stage valve, the hydraulic stage valve comprising a valve member movably mounted in a valve chamber to selectively meter fluid flow in a flow path from an upstream inlet port to a downstream outlet port and at least two variable-sized orifices disposed in the flow path between the inlet and outlet ports, an upstream pressure sensor, a downstream pressure sensor, a fluid temperature sensor, a position sensor sensing a linear position of the valve member, a controller that receives input from the upstream pressure sensor, the downstream pressure sensor, the fluid temperature sensor and the position sensor; and the controller configured to provide a control signal to the pilot stage valve as a function of the input from the upstream pressure sensor, the downstream pressure sensor, the fluid temperature sensor and the position sensor.

Claims

1. A flow control valve system comprising:

a pilot stage valve;

an hydraulic stage valve in fluid communication with said pilot stage valve;

said hydraulic stage valve comprising a valve member movably mounted in a valve chamber along a valve axis, and adapted to be moved along said valve axis to selectively meter fluid flow in a flow path from at least one inlet port defined between said valve member and said valve chamber and at least one outlet port defined between said valve member and said valve chamber;

said hydraulic stage valve comprising at least two variable-sized orifices defined between said valve member and said valve chamber and disposed in said flow path between said inlet port and said outlet port;

wherein said at least two variable-sized orifices are sized such that an upstream and downstream pressure ratio does not exceed a threshold ratio of 2.0;

an upstream pressure sensor;

a downstream pressure sensor;

a fluid temperature sensor;

a position sensor configured to sense a linear position of said valve member relative to said valve chamber;

a controller that receives input from said upstream pressure sensor, said downstream pressure sensor, said fluid temperature sensor and said position sensor; and

said controller configured to provide a control signal to said pilot stage valve as a function of said input from said upstream pressure sensor, said downstream pressure sensor, said fluid temperature sensor and said position sensor.

2. The flow control valve system set forth in claim 1, comprising a shutoff valve disposed in said flow path upstream of said inlet port.

3. The flow control valve system set forth in claim 1, comprising a filter disposed in said flow path upstream of said inlet port.

4. The flow control valve system set forth in claim 1, wherein said position sensor is selected from a group consisting of a linear variable differential transformer (LVDT), a Hall effect device (HED), an inductive sensor, a capacitive sensor and an encoder.

5. The flow control valve system set forth in claim 1, wherein said controller determines a calculated flow rate based on said input from said upstream pressure sensor, said downstream pressure sensor, said fluid temperature sensor and said position sensor.

6. The flow control valve system set forth in claim 5, wherein said controller comprises a look-up table having values loaded in a calibration process and determines said calculated flow rate based on said look-up table.

7. The flow control valve system set forth in claim 5, wherein said controller provides said control signal to said pilot stage valve based on said calculated flow rate.

8. The flow control valve system set forth in claim 7, wherein said controller provides said control signal to said pilot stage valve in a closed loop to minimize a difference between a commanded flow rate and said calculated flow rate.

9. The flow control valve system set forth in claim 1, wherein said fluid temperature sensor is disposed in said flow path upstream of said inlet port.

10. A method of controlling the flow of a fluid comprising the steps of:

providing an hydraulic valve having a valve member movably mounted in a valve chamber along a valve axis to selectively meter fluid flow in a flow path from at least one inlet port defined between said valve member and said valve chamber and at least one outlet port defined between said valve member and said valve chamber, and at least two variable-sized orifices defined between said valve member and said valve chamber and disposed in said flow path between said inlet port and said outlet port;

controlling the size of said at least two variable-sized orifices such that an upstream and downstream pressure ratio does not exceed a threshold ratio of 2.0;

providing a upstream pressure sensor, a downstream pressure sensor, a fluid temperature sensor, and a position sensor configured to sense a linear position of said valve member relative to said valve chamber;

providing a controller that receives input from said upstream pressure sensor, said downstream pressure sensor, said fluid temperature sensor and said position sensor; and

moving said valve member in said valve chamber along said valve axis to selectively meter fluid flow in said flow path as a function of said input from said upstream pressure sensor, said downstream pressure sensor, said fluid temperature sensor and said position sensor.

11. The method set forth in claim 10, comprising the step of determining a calculated flow rate based on said input from said upstream pressure sensor, said downstream pressure sensor, said fluid temperature sensor and said position sensor.

12. The method set forth in claim 11, comprising the step of exposing said hydraulic valve to a range of pressures and temperatures in a calibration process and determining said calculated flow rate based on at least one value from said calibration process accessed by said controller.

13. The method set forth in claim 12, wherein said value is recorded in a look-up table accessed by said controller.

14. The method set forth in claim 11, comprising the step of providing a control signal to said hydraulic valve in a closed loop to minimize a difference between a commanded flow rate and said calculated flow rate.

15. The method set forth in claim 14, wherein said hydraulic valve comprises a pilot stage valve in fluid communication with an hydraulic stage valve and said step of providing a control signal to said hydraulic valve in a closed loop to minimize a difference between a commanded flow rate and said calculated flow rate comprises the step of providing said control signal to said pilot stage valve.