Combined valve, power unit body and hydraulic power unit

Abstract

A combined valve for insertion into an elongated bore of a power unit body of a hydraulic power unit may have an elongated carrier for receiving a relief and a check valve. The valve may also have a register arranged at a first axial position of a longitudinal axis of the carrier for calibration of the relief valve. The valve may also have a check valve coupled to the carrier at a second axial position along the longitudinal axis of the carrier. The valve may also have a relief valve coupled to the carrier at a third axial position along the longitudinal axis of the carrier. A minimal distance between the first and the second axial position may be less than a minimal distance between the first and the third axial position.

Claims

1. A combined valve for insertion into an elongated bore of a power unit body of a hydraulic power unit, comprising: an elongated carrier for receiving a relief and a check valve, a register arranged at a first axial position of a longitudinal axis of the carrier for calibration of the relief valve; a check valve coupled to the carrier at a second axial position along the longitudinal axis of the carrier; a relief valve coupled to the carrier at a third axial position along the longitudinal axis of the carrier; wherein a minimal distance between the first and the second axial position is less than a minimal distance between the first and the third axial position.

2. The combined valve according to claim 1, wherein the relief valve comprises a compressible contrast spring and the register is configured to compress and/or decompress the contrast spring, wherein the register and/or the carrier are/is rotatable with respect to the contrast spring.

3. The combined valve according to claim 1, wherein the check valve comprises an actuator port, the relief valve comprises a tank port, and the check valve and the relief valve have a common pressure port located between the actuator port and the tank port, wherein the actuator port, the pressure port and the tank port are arranged along an axis parallel to the longitudinal axis of the combined valve.

4. The combined valve according to claim 3, wherein the check valve is configured to allow a fluid to flow from the pressure port to the actuator port and/or wherein the relief valve is configured to allow a fluid to flow from the pressure port to the tank port once a predetermined pressure is exceeded.

5. The combined valve according to claim 1, wherein the carrier comprises a mounting area for mounting on a power unit, including an external thread.

6. A power unit body for a hydraulic power unit, comprising: a first elongated bore extending from a first surface of the power unit body, extending substantially perpendicularly from the first surface of the power unit body, for receiving a combined valve, according to claim 1; the combined valve, arranged at least partially in the elongated bore; a first, a second and a third bore, each extending from a second surface of the power unit body, wherein the first bore forms a conduit connecting an actuator port of the combined valve with the second surface of the power unit body and the third bore forms a conduit connecting a tank port of the combined valve with the second surface of the power unit body.

7. A power unit body according to claim 6, wherein the second bore forms a conduit connecting a pressure port of the combined valve with the second surface of the power unit body and/or wherein the first and the second and the third bore are arranged parallel to one another.

8. A power unit body according to claim 6, comprising: a second elongated bore extending from the first surface of the power unit body, extending substantially parallel to the first elongated bore, a solenoid valve, arranged at least partially in the second elongated bore, wherein the first bore extends into the second elongated bore and/or the third bore extends into the second elongated bore.

9. The power unit body according to claim 6, wherein a carrier of the combined valve is rotatably arranged in the first elongated bore.

10. A hydraulic power unit, comprising: a power unit body according to claim 6, a tank fluidly connected to the tank port of the combined valve, a movable cylinder fluidly connected to the actuator port of the combined valve, a pump fluidly connected to the pressure port of the combined valve and to the tank, wherein the pump is configured to pump a fluid for controlling a movement of the cylinder an electric motor drivingly connected to the pump for driving the pump.

Description

DESCRIPTION OF THE FIGURES

(1) Further objects, advantages, and features will become more apparent upon reading of the following non-restrictive description of illustrative embodiments thereof, given by way of example only with reference to the accompanying drawings.

(2) In the appended drawings:

(3) FIG. 1 is a sectional view taken along a longitudinal axis of a combined valve showing a section of a power unit body according to FIG. 2, comprising a combined valve;

(4) FIG. 2 is a sectional view of a power unit body comprising a combined valve according to FIG. 1, the sectional view being taken along a longitudinal axis of the combined valve;

(5) FIG. 3 shows a schematic view of a power unit body; and

(6) FIG. 4 is a schematic view of a hydraulic power unit.

DETAILED DESCRIPTION

(7) FIG. 1 shows a combined valve 1 in a sectional view taken along a longitudinal axis L of the combined valve 1.

(8) The combined valve 1 comprises an elongated carrier 2, a relief valve 3 and a check valve 4. The relief valve 3 comprises a poppet 301 movably connected to the carrier 2. The poppet 301 may be moved between a first position and a second position along the longitudinal axis. In the first position, the poppet 301, in particular a coned part 301′ of the poppet 301, seals an inlet conduit 303 of the relief valve 3. In a second position of the poppet 301, the inlet conduit 303 is opened to allow a fluid to pass. The relief valve 3 further comprises a helical contrast spring 302 coupled to the poppet 301. In the first position of the poppet 301, the spring is in a decompressed state. In the second position of the poppet 301 the spring 302 is in a compressed state. The relief valve 3 comprises a pressure port P and a tank port T. When the inlet conduit 303 is open, the pressure port P and the tank port T are fluidly connected. When a fluid pressure in the inlet conduit 303 exceeds a predetermined value, the fluid applies a force to the poppet 301 compressing the spring 302. The compression of the spring 302 leads to a movement of the poppet from the first into the second position, thereby opening the inlet conduit 303 such that the fluid flows from the pressure port P to the tank port T. The predetermined value typically is at least 150 bar, preferably at least 180 bar, particularly preferably at least 220 bar. The predetermined value typically is at most 350, preferably at most 300 bar, particularly preferably at most 250 bar.

(9) The check valve 4 comprises a ball 401 arranged movably in a valve cavity 402. Further, the check valve comprises an inlet 403 and an outlet 404 fluidly connected to the valve cavity 402. The inlet 403 is fluidly connected to the pressure port P. The outlet 404 is fluidly connected to an actuator port C. The check valve 4 is configured to allow a fluid to pass from the inlet 403 to the outlet 404, while a reverse flow is blocked by the ball 401. When fluid is flowing from the pressure port P to the actuator port C, the ball 401 is in an open first position. When a fluid is entering the outlet 404, the ball 404 is moved to a closed second position such that a passage is blocked.

(10) The combined valve 1 further comprises a register 5 coupled to carrier 2. In the shown example, the register comprises a screw part 501 screwed into a first part 201 of the carrier 2. The register 5 is fixedly coupled to a second part 202 of the carrier 2 such that a rotation of the register 5 leads to a rotation of the second part 202 of the carrier 2 with respect to the first part 201 of the carrier 2. Further, a rotation of the register 5 in a first direction leads to a translational movement of the second part of carrier 202 and the coupled poppet 301, thereby compressing the spring 302. A rotation of the register 5 in a second direction opposite to the first direction, leads to a translational movement of the second part of carrier 202 and the coupled poppet 301, thereby decompressing the spring 302. When the register 5 is rotated, the spring 302 may also rotate. In another embodiment, the spring 302 is attached rotatably to the poppet 301 and/or the poppet 301 is attached rotatably to the carrier 2 such that the carrier 2 rotates with respect to the spring 302 when the register 5 is rotated.

(11) The register 5 is arranged at a first axial position I along the longitudinal axis L of the combined valve 1. In FIG. 1, the first axial position I is, for example, defined by the most exterior left axial position of the register. The check valve 4 is coupled to the carrier 2 at a second axial position II along the longitudinal axis L of the carrier 2. In FIG. 1, the third axial position II is defined, for example, by the axial position of the centre point of the ball 401. The relief valve 3 coupled to the carrier 2 at a third axial position III along the longitudinal axis L of the carrier 2. In FIG. 1, the third axial position III is defined, for example, by the most exterior left position of the poppet III.

(12) A minimal distance between the first axial position I and the second axial position II is less than a minimal distance between the first axial position I and the third axial position III. Thus, with regard to FIG. 1, the order of arrangement along the longitudinal axis, from the left to the right, is as follows: register, check valve, relief valve.

(13) The check valve 4 and the relief valve 3 have the common pressure port P located between the actuator port C and the tank port T. The actuator port, the pressure port and the tank port are arranged along an axis in parallel to the longitudinal axis L of the combined valve 1.

(14) In FIG. 2, a power unit body 6 is shown, comprising the combined valve 1 of FIG. 1.

(15) The carrier 2, in particular the first part 201 of the carrier 2, comprises a mounting area 201′ for mounting the combined valve on the power unit body 6. In the shown embodiment, the mounting area 201′ is an external thread. The power unit body 6 comprises a first elongated bore 600 extending from a first surface 601 of the power unit body 6, preferably extending essentially perpendicularly from the first surface 601 of the power unit body 6.

(16) The power unit body 6 comprises a first bore 611, a second bore 612 and a third bore 613, each extending from a second surface 602 of the power unit body 6.

(17) The combined valve 1 is arranged in the first elongated bore 601 such that the inlet 403 and the inlet 303 are associated with the pressure port P. The outlet 404 is associated with the actuator port C. An outlet of the relief valve 3 is associated with the tank port T. The first bore forms a first conduit 611′ connecting the actuator port C of the combined valve 1 with the second surface 602 of the power unit body 6. The second bore 612 forms a second conduit 612′ connecting the pressure port P of the combined valve with the second surface 602 of the power unit body 6. The third bore 613 forms a third conduit 613′ connecting the tank port T of the combined valve 1 with the second surface 602 of the power unit body 6.

(18) The first bore 611, the second bore 612 and the third bore 613 are arranged in parallel to one another. The first surface 601 and the second surface 602 are essentially perpendicular to one another. A second elongated bore 600′ extends from the first surface 601 of the power unit body 6. The second elongated bore 600′ extends essentially in parallel to the first elongated bore 600. A solenoid valve 7 is arranged at least partially in the second elongated bore 600′. The first bore 611 and the third bore 613 extend into the second elongated bore 600′ such that the solenoid valve 7 is fluidly connected to the actuator port C and the tank port T.

(19) FIG. 3 shows a schematic view of a power unit body 6 essentially similar to the power unit body 6 of FIG. 2, wherein the second bore 612″ is arranged essentially perpendicular to the first bore 611 and third bore 612. The second bore 612″ forms a second conduit 612′″ connecting the third surface 603 with the pressure port P of the combined valve. A hydraulic pump 8 may be arranged at the third surface 603 of the power unit 6. An outlet of the pump 8 may be associated with the pressure port P.

(20) FIG. 4 shows a schematic view of a hydraulic power unit 9 comprising a power unit body 6 of FIG. 2 or 3, the power unit body 6 comprising a combined valve 1 according to FIG. 1 and a solenoid valve 7. An electric Motor 10 is drivingly connected to the pump 8. The hydraulic power unit 9 further comprises a cylinder 11 fluidly connected to the check valve 4, a tank 12 and the solenoid valve 7. The pump 8 is connected to the tank 12 and is configured to pump a fluid through the check valve 4 to the cylinder 11 for moving a piston of the cylinder upwards, as depicted by arrow 13 in FIG. 4 (a). When the piston 11′ is in the upward position, as shown in FIG. 4 (b), a pressure in the inlet 303 may exceed a predetermined value such that the relief valve opens and the fluid may pass the relief valve 3 for flowing into the tank 12, as depicted by arrow 14. The pressure in the cylinder 11 may be controlled via the solenoid valve 7. When the solenoid valve 7 is opened, the fluid may pass through the solenoid valve 7 and into the tank 12, and the piston 11′ is moved downwards, as depicted by arrow 15 in FIG. 4 (c).

(21) Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features.

REFERENCE NUMERALS

(22) 1 combined valve 2 carrier 201 first part 201′ mounting area 202 second part 3 relief valve 301 poppet 302 spring 303 inlet conduit 4 check valve 401 ball 402 cavity 403 inlet 404 outlet 5 register 501 screw part 6 power unit body 600 first elongated bore 600′ second elongated bore 601 first surface 602 second surface 603 third surface 611 first bore 612 second bore 613 third bore 611′ first conduit 612′ second conduit 612″ second bore of embodiment of FIG. 3 612′″ second conduit of embodiment of FIG. 3 613′ third conduit 7 solenoid valve 8 pump 9 hydraulic power unit 10 electric motor 11 cylinder 11′ piston 12 tank 13 arrow 14 arrow 15 arrow C actuator port L longitudinal axis P pressure port T tank port