Independent and regenerative mode fluid control system

• US 6,715,403 B2
• Filed: 09/16/2002
• Issued: 04/06/2004
• Est. Priority Date: 10/12/2001
• Status: Expired due to Term

• Current Assignee: Caterpillar Sarl (Caterpillar Incorporated)
• Original Assignee: Caterpillar Incorporated, Shin Caterpillar Mitsubishi Ltd. (Caterpillar Incorporated)
• Inventors: Hajek, Thomas J. Jr., Tolappa, Srikrishnan T.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): Leslie, Michael
• Application Number:
  US10/244,077
• Publication Number:
  US 20030106423A1
• Time in Patent Office: 568 Days
• Field of Search: 91/6, 915/25, 915/31, 914/36, 604/14
• US Class Current: 91/531
• CPC Class Codes: E02F 9/2217 with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: E02F 9/2225 using pressure-compensating valves
• CPC Class Codes: F15B 11/024 by means of differential connection of the servomotor lines, e.g. regenerative circuits
• CPC Class Codes: F15B 11/16 with two or more servomotors
• CPC Class Codes: F15B 2011/0246 with variable regeneration flow
• CPC Class Codes: F15B 21/14 Energy-recuperation means
• CPC Class Codes: F15B 2211/30505 Non-return valves, i.e. check valves
• CPC Class Codes: F15B 2211/30575 in a Wheatstone Bridge arrangement (also half bridges)
• CPC Class Codes: F15B 2211/3058 having additional valves for interconnecting the fluid chambers of a double-acting actuator, e.g. for regeneration mode or for floating mode directional control valves having a regenerative position F15B2211/3133; directional control valves having a floating position F15B2211/3127
• CPC Class Codes: F15B 2211/3059 having multiple valves for multiple output members
• CPC Class Codes: F15B 2211/31588 having a single pressure source and multiple output members
• CPC Class Codes: F15B 2211/327 electrically or electronically
• CPC Class Codes: F15B 2211/351 Flow control by regulating means in feed line, i.e. meter-in control
• CPC Class Codes: F15B 2211/353 Flow control by regulating means in return line, i.e. meter-out control
• CPC Class Codes: F15B 2211/40515 with variable throttles or orifices
• CPC Class Codes: F15B 2211/41527 being connected to an output member and a directional control valve
• CPC Class Codes: F15B 2211/426 electrically or electronically
• CPC Class Codes: F15B 2211/71 Multiple output members, e.g. multiple hydraulic motors or cylinders
• CPC Class Codes: F15B 2211/78 Control of multiple output members

Abstract

A fluid control system is disclosed that includes a reservoir, a pump in fluid communication with the reservoir, a first double-acting actuator having a first head end chamber and a first rod end chamber, a second double-acting actuator having a second head end chamber and a second rod end chamber. The first and second double-acting actuators are selectively fluidly connected via a conduit. A first independent metering valve is configured to selectively provide fluid flow to the first and second double-acting actuators, and a second independent metering valve is configured to selectively provide fluid flow to the first and second double-acting actuators. The fluid control system also includes a proportional valve attached to the conduit between the first double-acting actuator and the second double-acting actuator. The proportional valve is capable of operating the fluid control system in either an independent function mode or a regenerative function mode.

Claims

1. A fluid control system, comprising:

a reservoir;

a pump in fluid communication with the reservoir;

a first double-acting actuator having a first head end chamber and a first rod end chamber;

a second double-acting actuator having a second head end chamber and a second rod end chamber, the first and second double-acting actuators being selectively fluidly connected via a conduit;

a first independent metering valve being configured to selectively provide fluid flow to the first and second double-acting actuators;

a second independent metering valve being configured to selectively provide fluid flow to the first and second double-acting actuators; and

a proportional valve attached to the conduit between the first double-acting actuator and the second double-acting actuator, the proportional valve being capable of operating the fluid control system in either an independent function mode or a regenerative function mode.

2. The fluid control system of claim 1, wherein the proportional valve is closed for the independent function mode and opened for the regenerative function mode.

3. The fluid control system of claim 2, wherein the first independent metering valve includes a first control port and a second control port connected to the second double-acting actuator, and the second independent metering valve includes a first control port and a second control port connected to the first double-acting actuator, wherein the first and second control ports of the first independent metering valve are connected to the head end chamber and the rod end chamber of the second double-acting actuator, respectively, and the first and second control ports of the second independent metering valve are connected to the rod end chamber and the head end chamber of the first double-acting actuator, respectively.

4. The fluid control system of claim 3, wherein the proportional valve is attached to the conduit between the rod end chamber of the first double-acting actuator and the head end chamber of the second double-acting actuator.

5. The fluid control system of claim 4, wherein, in the regenerative function mode, fluid in the rod end chamber of the first double-acting actuator flows toward the head end chamber of the second double-acting actuator or fluid in the head end chamber of the second double-acting actuator flows toward the rod end chamber of the first double-acting actuator.

6. The fluid control system of claim 1, further including a second conduit between the first double-acting actuator and the second double-acting actuator and a second proportional valve attached to the second conduit.

7. The fluid control system of claim 6, wherein the second proportional valve is attached to the second conduit between the rod end chamber of the second double-acting actuator and the head end chamber of the first double-acting actuator.

8. The fluid control system of claim 2, wherein the first independent metering valve includes a first control port connected to the first double-acting actuator and a second control port connected to the second double-acting actuator, and the second independent metering valve includes a first control port connected to the first double-acting actuator and a second control port connected to the second double-acting actuator, wherein the first and second control ports of the first independent metering valve are connected to the rod end chamber of the first double-acting actuator and the head end chamber of the second double-acting actuator, respectively, and the first and second control ports of the second independent metering valve are connected to the head end chamber of the first double-acting actuator and the rod end chamber of the second double-acting actuator, respectively.

9. The fluid control system of claim 8, wherein the proportional valve is attached to the conduit between the rod end chamber of the first double-acting actuator and the head end chamber of the second double-acting actuator.

10. The fluid control system of claim 9, wherein, in the regenerative function mode, fluid in the rod end chamber of the first double-acting actuator flows toward the head end chamber of the second double-acting actuator or fluid in the head end chamber of the second double-acting actuator flows toward the rod end chamber of the first double-acting actuator.

11. The fluid control system of claim 10, further including a second conduit between the first double-acting actuator and the second double-acting actuator and a second proportional valve attached to the second conduit.

12. The fluid control system of claim 11, wherein the second proportional valve is attached to the second conduit between the rod end chamber of the second double-acting actuator and the head end chamber of the first double-acting actuator.

13. A method of controlling fluid flow to and from first and second double-acting actuators in an independent function mode and a regenerative function mode, comprising:

providing a first independent metering valve having a first check valve in fluid communication with the first and second double-acting actuators;

providing a second independent metering valve having a second check valve in fluid communication with the first and second double-acting actuators;

providing a proportional valve in fluid communication with the first and second double-acting actuators;

operating the proportional valve to allow the first and second actuators to selectively operate in independent and regenerative function modes.

14. The method of claim 13, wherein the proportional valve is closed for the independent function mode and opened for the regenerative function mode.

15. The method of claim 13, wherein, in the regenerative function mode, fluid in a rod end chamber of the first double-acting actuator flows toward a head end chamber of the second double-acting actuator or fluid in the head end chamber of the second double-acting actuator flows toward the rod end chamber of the first double-acting actuator.