Solenoid valve for a portable hydraulic power unit

• US 10,705,554 B2
• Filed: 04/27/2018
• Issued: 07/07/2020
• Est. Priority Date: 04/28/2017
• Status: Active Grant

• Current Assignee: Graco Minnesota Incorporated (Graco Incorporated)
• Original Assignee: Graco Minnesota Incorporated (Graco Incorporated)
• Inventors: Dawson, Charles W., Luczak, Mariusz J., Mattson, Barry W., Ryder, Douglas S., Deneson, Bret A., Lins, Christopher A.
• Primary Examiner(s): Teka, Abiy
• Application Number:
  US15/965,028
• Publication Number:
  US 20180313350A1
• Time in Patent Office: 802 Days
• CPC Class Codes: F04B 1/02 having two cylinders in V-arrangement F04B1/04
• CPC Class Codes: F04B 11/005 using two or more pumping pistons
• CPC Class Codes: F04B 17/03 driven by electric motors
• CPC Class Codes: F04B 17/06 Mobile combinations
• CPC Class Codes: F04B 19/22 of reciprocating-piston type
• CPC Class Codes: F04B 2205/06 Pressure in a (hydraulic) circuit
• CPC Class Codes: F04B 23/02 having reservoirs
• CPC Class Codes: F04B 23/025 the pump being located directly adjacent the reservoir
• CPC Class Codes: F04B 23/026 a pump-side forming a wall of the reservoir
• CPC Class Codes: F04B 23/06 the pumps being all of reciprocating positive-displacement type
• CPC Class Codes: F04B 35/06 Mobile combinations
• CPC Class Codes: F04B 41/02 having reservoirs
• CPC Class Codes: F04B 49/08 Regulating by delivery pressure
• CPC Class Codes: F04B 49/225 with throttling valves or valves varying the pump inlet opening or the outlet opening
• CPC Class Codes: F04B 53/10 Valves; Arrangement of valves
• CPC Class Codes: F04B 9/02 the means being mechanical
• CPC Class Codes: F15B 1/26 Supply reservoir or sump assemblies
• CPC Class Codes: F15B 13/04 for use with a single servomotor
• CPC Class Codes: F15B 21/08 Servomotor systems incorporating electrically operated control means F15B21/02, F15B21/065 take precedence
• CPC Class Codes: F15B 2211/20584 Combinations of pumps with high and low capacity
• CPC Class Codes: F15B 2211/20592 : Combinations of pumps for supplying high and low pressure
• CPC Class Codes: F15B 2211/265 : Control of multiple pressure sources
• CPC Class Codes: F15B 2211/31582 : having multiple pressure sources and a single output member
• CPC Class Codes: F15B 2211/327 : electrically or electronically
• CPC Class Codes: F15B 2211/50518 : using pressure relief valves
• CPC Class Codes: F15B 2211/50536 : using unloading valves controlling the supply pressure by diverting fluid to the return line
• CPC Class Codes: F15B 2211/511 : the positions being discrete
• CPC Class Codes: F15B 2211/5157 : being connected to a pressure source and a return line
• CPC Class Codes: F15B 2211/5159 : being connected to an output member and a return line
• CPC Class Codes: F15B 2211/526 : electrically or electronically
• CPC Class Codes: F15B 2211/615 : Filtering means
• CPC Class Codes: F15B 2211/62 : Cooling or heating means
• CPC Class Codes: F15B 2211/6309 : the pressure being a pressure source supply pressure
• CPC Class Codes: F15B 2211/775 : Combined control, e.g. control of speed and force for providing a high speed approach stroke with low force followed by a low speed working stroke with high force, e.g. for a hydraulic press
• CPC Class Codes: G05G 1/04 : Controlling members for hand actuation by pivoting movement, e.g. levers
• CPC Class Codes: G05G 2505/00 : Means for preventing, limiting or returning the movements of parts of a control mechanism, e.g. locking controlling member
• CPC Class Codes: G05G 5/005 : for preventing unintentional use of a control mechanism G05G5/28 takes precedence

Abstract

A portable hydraulic power unit includes a fluid tank supported on a frame, a first pump configured to draw hydraulic fluid from the tank and a second pump configured to draw hydraulic fluid from the tank. The portable hydraulic power unit further includes a two-way valve disposed on a high-flow line extending from an output of the second pump, the two-way valve movable between an open state and a closed state. The two-way valve is electrically-actuated and configured to shift to the open state based on a hydraulic fluid pressure in a combined flow line downstream of the first pump and the second pump exceeding a threshold pressure level. The two-way valve directs the output of the second pump back to the fluid tank when the two-way valve is in the open state.

Claims

1. A hydraulic power unit for providing hydraulic fluid to a hydraulically-driven tool to power the hydraulically-driven tool comprising:

a fluid tank supported by a frame, the fluid tank configured to store a supply of hydraulic fluid;

a first pump configured to draw the hydraulic fluid from the fluid tank and pump a first hydraulic flow to a combined flow line;

a second pump configured to draw the hydraulic fluid from the fluid tank and pump a second hydraulic flow to a high-flow line, the high-flow line fluidly connected to the combined flow line, the combined flow line configured to provide the first hydraulic flow and the second hydraulic flow to the hydraulically-driven tool;

a first valve disposed along the high-flow line, the first valve controllable between an open state and a closed state; and

a high-flow return line extending from a downstream side of the first valve, the high-flow return line bypassing the combined flow line and the hydraulically-driven tool and configured to provide a return flow of the second hydraulic flow to the fluid tank;

wherein the first valve is an electrically-actuated valve configured to shift to the open state based on a hydraulic fluid pressure in the combined flow line exceeding a threshold pressure level, and wherein the first valve directs the second hydraulic flow to the high-flow return line in the open state.

2. The hydraulic power unit of claim 1, further comprising:

a drive mechanism mechanically linking the first pump and the second pump; and

a single electric motor configured to power the drive mechanism.

3. The hydraulic power unit of claim 1, further comprising:

a transducer configured to sense the hydraulic fluid pressure in the combined flow line and to generate a hydraulic pressure output; and

control circuitry configured to receive the hydraulic pressure output from the transducer and control the first valve between the open state and the closed state based on the hydraulic pressure output.

4. The hydraulic power unit of claim 3, wherein the control circuitry is configured to compare the hydraulic pressure output to the threshold pressure level and to control the first valve between the open state and the closed state based on the comparison of the hydraulic pressure output and the threshold pressure level.

5. The hydraulic power unit of claim 4, wherein the control circuitry is configured cause the first valve to shift to and remain in the open position based on the comparison of the hydraulic pressure output and the threshold pressure level indicating that the hydraulic fluid pressure in the combined flow line is at or above the threshold pressure level.

6. The hydraulic power unit of claim 5, wherein the control circuitry is configured to cause the first valve to shift to and remain in the closed position based on the comparison of the hydraulic pressure output and the threshold pressure level indicating that the hydraulic fluid pressure in the combined flow line is below the threshold level.

7. The hydraulic power unit of claim 3, wherein the threshold pressure level is between 3,000-4,000 psi.

8. The hydraulic power unit of claim 1, wherein the first valve is a solenoid-operated two-way valve.

9. The hydraulic power unit of claim 1, wherein the first pump is mechanically linked to the second pump such that a first piston of the first pump and a second piston of the second pump are configured to reciprocate simultaneously.

10. The hydraulic power unit of claim 9, wherein the first piston and the second piston are configured to reciprocate out of phase.

11. The hydraulic power unit of claim 9, and wherein:

the first piston includes a piston rod configured to reciprocate to pump the hydraulic fluid and having a first upper diameter portion and a first lower diameter portion, the first lower diameter portion having a larger diameter than the first upper diameter portion; and

the second piston includes a piston rod configured to reciprocate to pump the hydraulic fluid and having a second upper diameter portion and a second lower diameter portion, the second lower diameter portion having a larger diameter than the second upper diameter portion;

wherein the second lower diameter portion has a larger diameter than the first lower diameter portion.

12. The hydraulic power unit of claim 1, further comprising:

a second valve configured to direct the hydraulic fluid from the combined flow line to the hydraulically-driven tool, and to receive the hydraulic fluid from the hydraulically-driven tool and route the hydraulic fluid received from the hydraulically-driven tool to the fluid tank.

13. The hydraulic power unit of claim 1, further comprising:

a check valve disposed between the combined flow line and the high-flow line, the check valve configured to prevent hydraulic fluid in the combined flow line from flowing into the high-flow line.

14. The hydraulic power unit of claim 1, wherein the first pump is configured to pump the hydraulic fluid at pressures up to 10,000 psi, and the second pump is configured to pump the hydraulic fluid at pressures up to 3,500 psi.

15. A method comprising:

powering a first pump and a second pump of a hydraulic power unit simultaneously, the first pump drawing hydraulic fluid from a fluid reservoir and providing a first flow of the hydraulic fluid to a first valve, the second pump drawing hydraulic fluid from the fluid reservoir and providing a second flow of the hydraulic fluid to the first valve, wherein the first valve is configured to route the hydraulic fluid to a hydraulically-driven tool;

measuring, by a transducer, a hydraulic fluid pressure indicative of a pressure in a combined flow line upstream of the first valve; and

controlling a second valve between an open state and a closed state based on the measured hydraulic fluid pressure, wherein the second valve is configured to divert the second flow to a system return line when in the open state such that the second flow bypasses the combined flow line and the hydraulically-driven tool with the second valve in the open state.

16. The method of claim 15, further comprising:

diverting, with the second valve, the second flow to the system return line when the second valve is in the open state to prevent the second flow from flowing to the first valve and to the hydraulically-driven tool such that only the first flow powers the hydraulically-driven tool when the hydraulic fluid pressure is above a threshold pressure level; and

directing, with the second valve, the second flow to the first valve when the second valve is in the closed state such that both the first flow and the second flow power the hydraulically-driven tool when the hydraulic fluid pressure is below the threshold pressure level.

17. The method of claim 16, wherein the second valve diverts the second flow to the system return line when the second valve is in the open state to prevent a single electric motor that powers both the first pump and the second pump from being overwhelmed by hydraulic pressure demands of the hydraulically-driven tool.

18. The method of claim 15, wherein the step of controlling the second valve between the open state and the closed state based on the hydraulic fluid pressure comprises:

comparing, by a control circuitry of the hydraulic power unit, the hydraulic fluid pressure from the transducer to a threshold pressure level;

shifting the second valve to the open position based on the comparison indicating that the hydraulic fluid pressure is greater than or equal to the threshold pressure level; and

maintaining the second valve in the open position where the hydraulic fluid pressure exceeds the threshold pressure level.

19. The method of claim 18, further comprising:

shifting the second valve to the closed state based on the comparison indicating that the hydraulic fluid pressure is less than the threshold pressure level.

20. The method of claim 18, wherein the threshold pressure level is between 3,000-4,000 psi.

21. A hydraulic power unit for providing hydraulic fluid to a hydraulically-driven tool to power the hydraulically-driven tool comprising:

a fluid tank supported by a frame, the fluid tank configured to store a supply of hydraulic fluid;

a first pump configured to draw the hydraulic fluid from the fluid tank and pump a first hydraulic flow to a combined flow line;

a second pump configured to draw the hydraulic fluid from the fluid tank and pump a second hydraulic flow to a high-flow line, the high-flow line fluidly connected to the combined flow line;

a first valve disposed along the high-flow line, the first valve controllable between an open state and a closed state;

a high-flow return line extending from a downstream side of the first valve, the high-flow return line configured to provide a return flow of the second hydraulic flow to the fluid tank;

a transducer configured to sense the hydraulic fluid pressure in the combined flow line and to generate a hydraulic pressure output; and

control circuitry configured to receive the hydraulic pressure output from the transducer and control the first valve between the open state and the closed state based on the hydraulic pressure output;

wherein the first valve is an electrically-actuated valve configured to shift to the open state based on a hydraulic fluid pressure in the combined flow line exceeding a threshold pressure level, and wherein the first valve directs the second hydraulic flow to the high-flow return line in the open state;

wherein the threshold pressure level is between 3,000-4,000 psi.

22. A hydraulic power unit for providing hydraulic fluid to a hydraulically-driven tool to power the hydraulically-driven tool comprising:

a fluid tank supported by a frame, the fluid tank configured to store a supply of hydraulic fluid;

a first pump configured to draw the hydraulic fluid from the fluid tank and pump a first hydraulic flow to a combined flow line;

a second pump configured to draw the hydraulic fluid from the fluid tank and pump a second hydraulic flow to a high-flow line, the high-flow line fluidly connected to the combined flow line;

a first valve disposed along the high-flow line, the first valve controllable between an open state and a closed state; and

a high-flow return line extending from a downstream side of the first valve, the high-flow return line configured to provide a return flow of the second hydraulic flow to the fluid tank;

wherein the first valve is an electrically-actuated valve configured to shift to the open state based on a hydraulic fluid pressure in the combined flow line exceeding a threshold pressure level, and wherein the first valve directs the second hydraulic flow to the high-flow return line in the open state;

wherein the first pump is mechanically linked to the second pump such that a first piston of the first pump and a second piston of the second pump are configured to reciprocate simultaneously;

wherein the first piston includes a piston rod configured to reciprocate to pump the hydraulic fluid and having a first upper diameter portion and a first lower diameter portion, the first lower diameter portion having a larger diameter than the first upper diameter portion;

wherein the second piston includes a piston rod configured to reciprocate to pump the hydraulic fluid and having a second upper diameter portion and a second lower diameter portion, the second lower diameter portion having a larger diameter than the second upper diameter portion; and

wherein the second lower diameter portion has a larger diameter than the first lower diameter portion.

23. A hydraulic power unit for providing hydraulic fluid to a hydraulically-driven tool to power the hydraulically-driven tool comprising:

a fluid tank supported by a frame, the fluid tank configured to store a supply of hydraulic fluid;

a first pump configured to draw the hydraulic fluid from the fluid tank and pump a first hydraulic flow to a combined flow line;

a second pump configured to draw the hydraulic fluid from the fluid tank and pump a second hydraulic flow to a high-flow line, the high-flow line fluidly connected to the combined flow line;

a first valve disposed along the high-flow line, the first valve controllable between an open state and a closed state; and

a high-flow return line extending from a downstream side of the first valve, the high-flow return line configured to provide a return flow of the second hydraulic flow to the fluid tank;

wherein the first valve is an electrically-actuated valve configured to shift to the open state based on a hydraulic fluid pressure in the combined flow line exceeding a threshold pressure level, and wherein the first valve directs the second hydraulic flow to the high-flow return line in the open state;

wherein the first pump is configured to pump the hydraulic fluid at pressures up to 10,000 psi, and the second pump is configured to pump the hydraulic fluid at pressures up to 3,500 psi.

24. A method comprising:

powering a first pump and a second pump of a hydraulic power unit simultaneously, the first pump drawing hydraulic fluid from a fluid reservoir and providing a first flow of the hydraulic fluid to a first valve, the second pump drawing hydraulic fluid from the fluid reservoir and providing a second flow of the hydraulic fluid to the first valve, wherein the first valve is configured to route the hydraulic fluid to a hydraulically-driven tool;

measuring, by a transducer, a hydraulic fluid pressure indicative of a pressure in a combined flow line upstream of the first valve; and

controlling a second valve between an open state and a closed state based on the measured hydraulic fluid pressure by;

comparing, by a control circuitry of the hydraulic power unit, the hydraulic fluid pressure from the transducer to a threshold pressure level;

shifting the second valve to the open position based on the comparison indicating that the hydraulic fluid pressure is greater than or equal to the threshold pressure level; and

maintaining the second valve in the open position where the hydraulic fluid pressure exceeds the threshold pressure level;

wherein the second valve is configured to divert the second flow to a system return line when in the open state; and

wherein the threshold pressure level is between 3,000-4,000 psi.