Dual pressure logic for a track drill circuit

Patent metadata

Field	Value
Publication number	US-10323458-B2
Application number	US-201615331222-A
Country	US
Kind code	B2
Filing date	Oct 21, 2016
Priority date	Oct 21, 2016
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

A hydraulic circuit may be used for controlling a plurality of hydraulic implements. The hydraulic circuit may include a first directional valve, a second directional valve, and a relief valve. A variable displacement pump may be fluidly coupled to the first directional valve, the second directional valve, and the relief valve. The hydraulic circuit may be communicably and operably coupled to a controller, and the controller may be programmed to selectably control the hydraulic circuit between a first operational mode and a second operational mode. Additionally, the controller may be programmed to actuate the first directional valve between an open position and a closed position and to actuate the second directional valve between a first open position, a second open position, a first closed position and a second closed position.

First claim

What is claimed is:

1. A hydraulic circuit having a variable hydraulic pressure, the hydraulic circuit comprising:
a reservoir configured to store a hydraulic fluid;
a variable displacement pump being selectable between a first operational mode and a second operational mode, and the variable displacement pump configured to pump the hydraulic fluid through a hydraulic fluid line;
a first hydraulic implement and a second hydraulic implement fluidly connected to the hydraulic fluid line and the first hydraulic implement and the second hydraulic implement configured to receive the hydraulic fluid from the variable displacement pump;
a pressure compensated selector solenoid valve coupled to the hydraulic fluid line;
a pressure compensated control valve coupled to the hydraulic fluid line, the pressure compensated control valve having an open positon for fluidly connecting the first hydraulic implement and a relief valve to the variable displacement pump, an output of the relief valve being fluidly connected to a return line of the reservoir, and the pressure compensated control valve having a closed position for fluidly isolating the relief valve from the variable displacement pump, wherein the open position of the pressure compensated control valve activates the first operational mode of the variable displacement pump.

2. The hydraulic circuit of claim 1 , wherein the first operational mode is a pressure compensated mode that operates the variable displacement pump at a fixed pressure setting, and the relief valve is configured to maintain a pre-determined pressure of the hydraulic fluid to actuate the first hydraulic implement such that the variable displacement pump supplies a constant pressure to the first hydraulic implement.

3. The hydraulic circuit of claim 1 , wherein the first hydraulic implement is a hydraulic actuated drill.

4. The hydraulic circuit of claim 1 , wherein the closed position of the pressure compensated control valve activates the second operational mode of the variable displacement pump.

5. The hydraulic circuit of claim 4 , wherein the second operational mode is a load sense mode, and the load sense mode comprises an adjustable pressure output of the variable displacement pump based on a sensed load of the second hydraulic implement.

6. The hydraulic circuit of claim 5 , wherein the second hydraulic implement includes at least one tram motor.

7. The hydraulic circuit of claim 1 , further comprising a controller operatively coupled to a pressure compensated selector solenoid valve, the controller being programmed to activate and deactivate the pressure compensated selector solenoid valve to selectively control the the hydraulic circuit between the first operational mode and the second operational mode of the variable displacement pump.

8. A hydraulic control system for controlling a plurality of hydraulic implements, the hydraulic control system comprising:
a hydraulic circuit having a pressure compensated control valve a load sense control valve and a pressure compensated selector solenoid valve;
a relief valve fluidly coupled to the pressure compensated control valve;
a variable displacement pump fluidly coupled to the pressure compensated control valve and the load sense control valve;
a first hydraulic implement and a second hydraulic implement configured to receive a hydraulic fluid pumped through a hydraulic fluid line by the variable displacement pump; and
a controller operably and communicably coupled to the pressure compensated selector solenoid valve included in the hydraulic circuit, the controller being programmed to activate and deactivate the pressure compensated selector solenoid valve to selectably control the hydraulic circuit between a first operational mode and a second operational mode, wherein the controller selectably controls the pressure compensated solenoid valve to operate the hydraulic circuit in the first operational mode which positions the pressure compensated control valve into an open position such that the first hydraulic implement and the relief valve being fluidly coupled to the variable displacement pump.

9. The hydraulic control system of claim 8 , wherein the first operational mode of the hydraulic circuit is a pressure compensated mode that operates the variable displacement pump at a fixed pressure setting, and the relief valve is configured to maintain a pre-determined pressure of the hydraulic fluid to actuate the first hydraulic implement such that the variable displacement pump supplies a constant pressure to the first hydraulic implement.

10. The hydraulic control system of claim 8 , wherein the first hydraulic implement is a hydraulic actuated drill.

11. The hydraulic control system of claim 8 , wherein the controller selectably controls the hydraulic circuit to operate in the second operational mode, the controller actuating the pressure compensated control valve into the closed position such that the variable displacement pump being fluidly coupled to the second hydraulic implement.

12. The hydraulic control system of claim 11 , wherein the second operational mode of the hydraulic circuit is a load sense mode, and the load sense mode further comprises an adjustable pressure output of the variable displacement pump based on a sensed load of the second hydraulic implement.

13. The hydraulic control system of claim 12 , wherein the second hydraulic implement includes at least one tram motor.

14. A machine having a hydraulic control system, the machine comprising:
a reservoir configured to store a hydraulic fluid;
a pressure compensated selector solenoid valve selectively operated to direct the hydraulic fluid;
a variable displacement pump coupled to the reservoir and the variable displacement pump configured to be selectable between a first operational mode and a second operational mode, and the variable displacement pump is configured to pump the hydraulic fluid through a hydraulic fluid line of the hydraulic control system;
a first hydraulic implement and a second hydraulic implement being fluidly coupled to the variable displacement pump through the hydraulic fluid line, and the hydraulic fluid supplied by the variable displacement pump through the hydraulic fluid line for actuation of the first hydraulic implement and the second hydraulic implement;
a pressure compensated control valve coupled to the hydraulic fluid line, the pressure compensated control valve having an open positon for fluidly connecting the first hydraulic implement and a relief valve to the variable displacement pump, an output of the relief valve being fluidly coupled to a return line of the reservoir, and the pressure compensated control valve having a closed position for fluidly isolating the relief valve from the variable displacement pump; and
a controller operably and communicably coupled to the pressure compensated selector solenoid valve, the controller being programmed to activate and deactivate the pressure compensated selector solenoid valve to selectably control the variable displacement pump between the first operational mode and the second operational mode, wherein the first operational mode is a pressure compensated mode that operates the variable displacement pump at a fixed pressure setting, and wherein the relief valve is configured to maintain a pre-determined pressure of the hydraulic fluid to actuate the first hydraulic implement such that the variable displacement pump supplies a constant pressure to the first hydraulic implement.

15. The machine of claim 14 , wherein the first hydraulic implement is a hydraulic actuated drill.

16. Th

Assignees

• Caterpillar Inc

Inventors

• Chiaramonte Michael P
• Demick Christopher J

Classifications

• F15B11/165

  for adjusting the pump output or bypass in response to demand · CPC title

• F15B2211/5157

  being connected to a pressure source and a return line · CPC title

• F15B2211/6658

  Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode · CPC title

• E02F9/2235

  including an electronic controller · CPC title

• E21B7/022 Primary

  Control of the drilling operation; Hydraulic or pneumatic means for activation or operation (control circuits for drilling masts E21B15/045) · CPC title