Fluid pressure circuit

Patent metadata

Field	Value
Publication number	US-2025035132-A1
Application number	US-202218714010-A
Country	US
Kind code	A1
Filing date	Nov 30, 2022
Priority date	Dec 9, 2021
Publication date	Jan 30, 2025
Grant date	—

Abstract

There is provided a fluid pressure circuit capable of preventing unintentional operation of a cylinder device. A return flow passage through which a return fluid flows from a cylinder device to a regenerative drive source is provided with a control valve that opens the flow passage in response to an operation of an operating device.

First claim

1 . A fluid pressure circuit, comprising:
a tank that is configured to store a fluid; a fluid supply source configured to supply the fluid in the tank; a cylinder device extended and retracted by the fluid from the fluid supply source; a switching valve disposed between the fluid supply source and the cylinder device configured to switch between flow passages of the fluid; a flow diversion valve located closer to a side of the cylinder device than the switching valve and configured to divert at least some of a return fluid returning from the cylinder device to the tank; a regenerative drive source driven in a regenerative mode by the diverted return fluid; an operating device configured to output a switching command corresponding to an operation to the switching valve; and an actuating device configured to output a switching command to the flow diversion valve in response to operation of the operating device, wherein a return flow passage through which the return fluid flows from the cylinder device to the regenerative drive source is provided with a control valve configured to open the flow passage in response to the operation of the operating device.

2 . The fluid pressure circuit according to claim 1 ,
wherein the actuating device is configured to detect the operation of the operating device as an electric signal, and to output the switching command to the flow diversion valve.

3 . The fluid pressure circuit according to claim 1 ,
wherein the control valve is a pilot valve that is configured to be switched by a pilot pressure, and the flow diversion valve is an electromagnetic valve that is configured to be switched by electricity.

4 . The fluid pressure circuit according to claim 3 ,
wherein the switching valve is a pilot valve, and the switching valve and the control valve are configured to be switched by the pilot pressure.

5 . The fluid pressure circuit according to claim 1 ,
wherein the control valve is provided in a flow passage between the cylinder device and the flow diversion valve.

6 . The fluid pressure circuit according to claim 1 ,
wherein a housing of the flow diversion valve and a housing of the control valve are separate bodies, and are configured such that the flow passages are connected by stacking and fixing the housings.

7 . The fluid pressure circuit according to claim 2 ,
wherein the control valve is configured to be a pilot valve that is switched by a pilot pressure, and the flow diversion valve is an electromagnetic valve that is configured to be switched by electricity.

8 . The fluid pressure circuit according to claim 7 ,
wherein the switching valve is a pilot valve, and the switching valve and the control valve are configured to be switched by the pilot pressure.

9 . The fluid pressure circuit according to claim 2 ,
wherein the control valve is provided in a flow passage between the cylinder device and the flow diversion valve.

10 . The fluid pressure circuit according to claim 2 ,
wherein a housing of the flow diversion valve and a housing of the control valve are separate bodies, and are configured such that the flow passages are connected by stacking and fixing the housings.

Assignees

• Eagle Ind Co Ltd

Inventors

• Shimada Yoshiyuki

Classifications

• E02F9/2267

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

• F15B2211/865

  Prevention of failures · CPC title

• F15B2211/665

  Methods of control using electronic components · CPC title

• F15B2211/6346

  representing a state of input means, e.g. joystick position · CPC title

• F15B2211/30515

  Load holding valves · CPC title