Independent supply and exhaust metering within a valve casting

Patent metadata

Field	Value
Publication number	US-9222241-B2
Application number	US-201113167318-A
Country	US
Kind code	B2
Filing date	Jun 23, 2011
Priority date	Jun 23, 2011
Publication date	Dec 29, 2015
Grant date	Dec 29, 2015

Abstract

The present disclosure provides a hydraulic system for controlling a load. The system includes a housing defining an inlet, a first port, and a second port. The system further includes a spool valve and a proportional control element. The spool valve is in fluid communication with the inlet and the second port and the proportional control element is in fluid communication with the first port. The proportional control element can be controllable to exhaust fluid from the first port to a reservoir. In this arrangement, the proportional control element and the spool valve are controlled independently of one another.

First claim

The invention claimed is:

1. A hydraulic system including a reservoir, the hydraulic system for controlling a load, comprising:
a housing defining an inlet, a first port, a second port, and a tank galley coupled to the reservoir;
a spool valve, including a spool configured to move within the housing, the spool being in fluid communication with the inlet, the first port, the second port, and the tank galley, wherein the spool is configured to meter fluid flow from the inlet to the first port and to meter fluid flow from the second port to the tank galley simultaneously due to the configuration of the spool; and
a proportional control element, disposed in the housing and in fluid communication with the second port, wherein the proportional control element is configured to control the fluid flow from the second port, through the housing and past the spool, to the tank galley, and to the reservoir;
wherein, the proportional control element and the spool valve are configured to be controlled independently of one another.

2. The system of claim 1 , wherein the proportional control element comprises a solenoid.

3. The system of claim 1 , wherein the proportional control element comprises a pressure relief orifice.

4. The system of claim 1 , wherein the proportional control element comprises an open position and a closed position, the second port, the reservoir, and a pump defining a fluid path with the inlet in the open position.

5. The system of claim 1 , further comprising a cylinder being in fluid communication with the first port and the second port.

6. The system of claim 5 , further comprising a pump in fluid communication with the inlet.

7. The system of claim 6 , further comprising an inlet valve disposed near the inlet, the inlet valve configured to fluidly couple the pump to the first port.

8. The system of claim 1 , further comprising a bridge channel defined in the housing, the bridge channel being fluidly coupled between the inlet and the first port.

9. The system of claim 1 , further comprising a compensator valve disposed in the housing between the first port and the second port, the compensator valve being in fluid communication with the spool valve and configured to maintain a pressure drop across the spool valve.

10. A hydraulic system for controlling a work element attached to an off road work vehicle, comprising:
a housing defining an inlet, a first port, a second port, and a tank galley;
a pump configured to be in fluid communication with the inlet;
a cylinder assembly including a rod, the cylinder assembly having a first end fluidly coupled to the first port and a second end fluidly coupled to the second port;
a single spool valve disposed in the housing, the spool valve being moveable to an open position to fluidly couple and to meter fluid flow from the inlet and the first port, wherein the single spool valve is further configured in the open position to selectively fluidly couple and to meter fluid flow from the second port to the tank galley, and wherein the metered fluid flow from the inlet to the first port and the metered fluid flow from the second port to the tank galley is made at the same time due to the configuration of the single spool valve; and
a proportional control element disposed in the housing and being in fluid communication with the second port and the tank galley, wherein the proportional control element is configured to proportionally control the fluid flow from the second port, past the single spool valve, and to the tank galley;
wherein, the single spool valve and the proportional control element are controlled independently of one another.

11. The hydraulic system of claim 10 , further comprising an inlet valve disposed near the inlet, wherein the inlet and first port are fluidly coupled when the inlet valve and spool valve are disposed in open positions.

12. The hydraulic system of claim 10 , further comprising a fluid path defined between the inlet and first port, the fluid path including a bridge portion between the spool valve and first port.

13. The hydraulic system of claim 10 , further comprising a compensator valve disposed in a defined passage in the housing between the first port and the second port, the compensator valve being in fluid communication with the spool valve and configured to maintain a relatively constant pressure drop across the spool valve.

14. The hydraulic system of claim 10 , further comprising:
a tank reservoir in fluid communication with the pump; and
a solenoid for controlling the proportional control element;
wherein, the solenoid causes the proportional control element to exhaust fluid from the second port to the tank reservoir and through the tank galley without moving the spool valve.

15. The hydraulic system of claim 10 , further comprising:
a first flow path defined in the housing and in fluid communication with the inlet and the first port; and
a second flow path defined in the housing and in fluid communication with the second port;
wherein the first flow path and second flow path are at least partially parallel to one another.

16. The hydraulic system of claim 10 , further comprising:
a tank reservoir in fluid communication with the tank galley and with the pump;
a first configuration in which the spool valve is in the open position and the proportional control element is in a closed position, where the inlet is fluidly coupled to the first port;
a second configuration in which the spool valve is in a closed position and the proportional control element is in an open position, where fluid can flow from the second port past the proportional control element; and
a third configuration in which the spool valve and proportional control element are both open, where the first port, second port, and inlet define a fluid path through the reservoir and through the pump.

17. The hydraulic system of claim 1 , wherein the spool is configured to include a first notch and a second notch located a predetermined distance from the first notch, wherein the spool is configured to be moveable between an open position and a closed position, the open position configured to meter fluid flow past the first notch between the inlet and the first port and to meter fluid flow past the second notch between the second port and the tank galley.

Assignees

• Graeve Joshua D
• Deere & Co

Inventors

• Graeve Joshua D

Classifications

• F15B13/021

  Valves for interconnecting the fluid chambers of an actuator · CPC title

• F15B13/0402

  for linearly sliding valves, e.g. spool valves · CPC title

• F15B13/024

  Pressure relief valves · CPC title

• E02F9/2267 Primary

  Valves or distributors (position of valves arrangements on upper-structures E02F9/0875) · CPC title

• Y10T137/86646

  Plug type · CPC title