Proportional hydraulic valve

Patent metadata

Field	Value
Publication number	US-11346458-B2
Application number	US-202016841363-A
Country	US
Kind code	B2
Filing date	Apr 6, 2020
Priority date	Apr 17, 2019
Publication date	May 31, 2022
Grant date	May 31, 2022

Abstract

A proportional hydraulic valve has a valve housing, an actuating device and a valve piston axially movable in a piston chamber of the valve housing. The valve housing has at least one pressure connection and at least one connection port. The valve piston blocks a flow path between the pressure connection and the connection port or releases it proportionally by moving the valve piston proportionally to an actuating force generated by the actuating device between a closed position and an open position. The valve piston has a first and a second spool area with a circumferential recess in the axial direction after the first and before the second spool area. The recess together with the piston chamber forms a pressure chamber and the pressure connection opens into the pressure chamber. A first diameter of the first spool area is larger than a second diameter of the second spool area.

First claim

The invention claimed is:

1. A proportional hydraulic valve, comprising:
a valve housing having a piston chamber, the valve housing having at least one pressure connection and at least one connection port;
an actuating device;
a valve piston axially movable in the piston chamber of the valve housing between a closed position and an open position, the valve piston operable to block or proportionally release a flow path between the pressure connection and the connection port by the valve piston moving proportionally to an actuating force generated by the actuating device between the closed position and the open position in the piston chamber; and
the valve piston having a first spool area having a first diameter and a second spool area having a second diameter, the first and second spool areas being guided in and sliding against respective first and second guide sections a guide section of the piston chamber, the first diameter being larger than the second diameter, the first spool area having a first face and the second spool area having a second face, the valve piston further having a circumferential recess after the first spool area and before the second spool area in an axial direction, the circumferential recess together with the piston chamber forming a pressure chamber between the first and second faces, the pressure connection being the only port opening into the pressure chamber in the closed position of the valve piston, the pressure connection opening into and providing fluid into the pressure chamber regardless of whether the valve piston is in the open position or the closed position;
the pressure chamber having a pressurized differential area defined as a difference between the area of the first spool area as a function of the first diameter and the area of the second spool area as a function of the second diameter.

2. The proportional hydraulic valve according to claim 1 , wherein:
the valve piston has a closing element in front of the first spool area in the axial direction; and
the valve housing has a valve seat;
the closing element resting on the valve seat when the valve piston is in the closed position.

3. The proportional hydraulic valve according to claim 2 , wherein the closing element is a valve cone.

4. The proportional hydraulic valve according to claim 2 , wherein the piston chamber has a first annular groove in front of the pressure connection in the axial direction, the connection port opening into the first annular groove and the valve seat being formed on a circumferential edge of the first annular groove, the first spool area positively covering the valve seat on a lift-off movement path.

5. The proportional hydraulic valve according to claim 1 , wherein the valve piston has at least one cut portion which extends axially from the circumferential recess into the first spool area, the at least one cut portion being radially only partially circumferential.

6. The proportional hydraulic valve according to claim 5 , wherein the at least one cut portion at least partially has a cross-sectional area which increases in the axial direction.

7. The proportional hydraulic valve according to claim 5 , wherein the at least one cut portion comprises two or more cut portions evenly distributed around the circumference.

8. The proportional hydraulic valve according to claim 1 , wherein:
the piston chamber has a damping chamber at one axial end
the valve piston has a circumferential damping groove which is in fluidic connection with the connection port; and
a damping gap extends axially from the damping groove between the valve piston and the piston chamber, the damping gap being in fluidic connection with the damping chamber.

9. The proportional hydraulic valve according to claim 8 , wherein:
the second spool area is guided in a guide section of the piston chamber;
the damping chamber is arranged in the axial direction after the guide section; and
the damping groove is formed on the second spool area so that the damping gap extends in the axial direction.

10. The proportional hydraulic valve according to claim 8 , wherein:
the valve piston has an axial blind bore, a first bore passing radially through the valve piston, and a second bore passing radially through the valve piston, the first bore being in fluidic connection with the connection port and the second bore being in fluidic connection with the damping groove.

11. The proportional hydraulic valve according to claim 1 , further comprising at least one circumferential second annular groove is disposed on the second spool area.

12. The proportional hydraulic valve according to claim 1 , wherein the hydraulic valve is a proportional pressure limiting valve.

13. The proportional hydraulic valve according to claim 1 , wherein the hydraulic valve is a pilot-operated valve.

14. A hydraulic system with a proportional hydraulic valve according to claim 1 .

15. A proportional hydraulic valve, comprising:
a valve housing having a piston chamber, the valve housing having at least one pressure connection and at least one connection port;
an actuating device;
a valve piston axially movable in the piston chamber of the valve housing between a closed position and an open position, the valve piston operable to block or proportionally release a flow path between the pressure connection and the connection port by the valve piston moving proportionally to an actuating force generated by the actuating device between the closed position and the open position in the piston chamber; and
the valve piston having a first spool area having a first diameter and a second spool area having a second diameter, the first and second spool areas being guided in and sliding against respective first and second guide sections of the piston chamber, the first diameter being larger than the second diameter, the first spool area having a first face and the second spool area having a second face, the valve piston further having a circumferential recess after the first spool area and before the second spool area in an axial direction, the circumferential recess together with the piston chamber forming a pressure chamber between the first and second faces, the pressure connection opening into the pressure chamber regardless of whether the valve piston is in the open position or the closed position;
the pressure chamber having a pressurized differential area defined as a difference between the area of the first spool area as a function of the first diameter and the area of the second spool area as a function of the second diameter;
wherein the proportional hydraulic valve consists of only two ports.

16. The proportional hydraulic valve according to claim 15 , wherein:
the valve piston has a closing element in front of the first spool area in the axial direction; and
the valve housing has a valve seat;
the closing element resting on the valve seat when the valve piston is in the closed position.

17. The proportional hydraulic valve according to claim 16 , wherein the closing element is a valve cone.

18. The proportional hydraulic valve according to claim 16 , wherein the piston chamber has a first annular groove in front of the pressure connection in the axial direction, the connection port opening into the first annular groove and the valve seat being formed on a circumferential edge of the first annular groove, the first spool area positively covering the valve seat on a lift-off movement path.

19. The proportional hydraulic valve according to claim 15 , wherein the valve piston has at

Assignees

• Hawe Hydraulik Se

Inventors

• Wechsel Thomas
• Faber Bernd

Classifications

• F15B13/027

  Check valves · CPC title

• F16K31/363

  the fluid acting on a piston (F16K31/38 takes precedence) · CPC title

• F16K31/0613 Primary

  with cylindrical slides · CPC title

• F16K31/163 Primary

  the fluid acting on a piston · CPC title

• F15B13/022

  Flow-dividers; Priority valves · CPC title