Hydraulic valve assembly with forced circuit

Abstract

A hydraulic valve assembly includes a first spool valve and a first selector valve for actuating a first hydraulic consumer port or a second hydraulic consumer port, and a second spool valve and a second selector valve for actuating a third hydraulic consumer port or a fourth hydraulic consumer port. A shut-off valve is arranged in a common pressure channel. A branch channel with first and second pressure branch channels branches off the pressure channel upstream of the shut-off valve. The first selector valve connects the first pressure branch channel to a first connection line in a first switching position and connects the second pressure branch channel to a second connection line in a second switching position. The second selector valve, in a first switching position, connects the first connection line to the control channel and, in a second switching position, connects the second connection line to the control channel.

Claims

1. A hydraulic valve assembly comprising: a first control device with first and second hydraulic consumer ports; a second control device with third and fourth hydraulic consumer ports; a common pressure channel for supplying pressure to the first and second control devices; and a return channel; wherein the first control device has a first spool valve and a first selector valve for actuating the first hydraulic consumer port in a first switching position of the first selector valve or the second hydraulic consumer port in a second switching position of the first selector valve; wherein the second control device has a second spool valve and a second selector valve for actuating the third hydraulic consumer port in a first switching position of the second selector valve or the fourth hydraulic consumer port in a second switching position of the second selector valve; wherein a shut-off valve for interrupting the pressure supply to the first and second control devices is arranged in the pressure channel and pressure pilot-controlled in an opening direction via a control channel; wherein upstream of the shut-off valve a branch channel with first and second pressure branch channels branches off from the pressure channel; wherein the first selector valve in the first switching position connects the first pressure branch channel to a first connection line and blocks the second pressure branch channel, and in the second switching position connects the second pressure branch channel to a second connection line and blocks the first pressure branch channel; and wherein the second selector valve in the first switching position connects the first connection line to the control channel and blocks the second connection line, and in the second switching position connects the second connection line to the control channel and blocks the first connection line.

2. The hydraulic valve assembly according to claim 1, wherein the first selector valve and/or the second selector valve are spool valves.

3. The hydraulic valve assembly according to claim 1 further comprising a relief line that leads from the control channel into the return channel.

4. The hydraulic valve assembly according to claim 3 further comprising a hydraulic resistor arranged in the relief line.

5. The hydraulic valve assembly according to claim 1, wherein the shut-off valve is spring-loaded in the shut-off direction.

6. The hydraulic valve assembly according to claim 1, wherein the shut-off valve is a seated valve.

7. The hydraulic valve assembly according to claim 1 further comprising a closing valve arranged in the control channel.

8. The hydraulic valve assembly according to claim 7, wherein the closing valve can be operated manually.

9. The hydraulic valve assembly according to claim 1, wherein the first selector valve and the second selector valve are coupled so that the first selector valve and the second selector valve can each be switched together to the respective first switching position or second switching position.

10. A mobile hydraulic system comprising the hydraulic valve assembly according to claim 1.

11. A hydraulic valve assembly comprising: a first control device with first and second hydraulic consumer ports, wherein the first control device has a first spool valve and a first selector valve for actuating the first hydraulic consumer port in a first switching position of the first selector valve or the second hydraulic consumer port in a second switching position of the first selector valve; a second control device with third and fourth hydraulic consumer ports, wherein the second control device has a second spool valve and a second selector valve for actuating the third hydraulic consumer port in a first switching position of the second selector valve or the fourth hydraulic consumer port in a second switching position of the second selector valve; a common pressure channel for supplying pressure to the first and second control devices; a shut-off valve arranged in the pressure channel for interrupting the pressure supply to the first and second control devices, wherein the shut-off valve is pressure pilot-controlled in an open direction via a control channel; and a branch channel that branches off the pressure channel upstream of the shut-off valve and that includes first and second pressure branch channels; wherein the first selector valve in the first switching position connects the first pressure branch channel to a first connection line and blocks the second pressure branch channel, and in the second switching position connects the second pressure branch channel to a second connection line and blocks the first pressure branch channel; and wherein the second selector valve in the first switching position connects the first connection line to the control channel and blocks the second connection line, and in the second switching position connects the second connection line to the control channel and blocks the first connection line.

12. The hydraulic valve assembly according to claim 11, wherein the first selector valve and/or the second selector valve are spool valves.

13. The hydraulic valve assembly according to claim 11, wherein the shut-off valve is spring-loaded in the shut-off direction.

14. The hydraulic valve assembly according to claim 11, wherein the shut-off valve is a seated valve.

15. The hydraulic valve assembly according to claim 11 further comprising a closing valve arranged in the control channel.

16. The hydraulic valve assembly according to claim 15, wherein the closing valve can be operated manually.

17. The hydraulic valve assembly according to claim 11, wherein the first selector valve and the second selector valve are coupled so that the first selector valve and the second selector valve can each be switched together to the respective first switching position or second switching position.

18. A mobile hydraulic system comprising the hydraulic valve assembly according to claim 11.

Description

DESCRIPTION OF THE DRAWING

(1) THE FIGURE shows a hydraulic circuit diagram of a hydraulic valve assembly according to the disclosure.

DETAILED DESCRIPTION

(2) The illustrated hydraulic valve assembly 1 has a first control device 2 and a second control device 3. The first control device 2 has a total of four hydraulic consumer ports A1, A2, B1 and B2. The effective consumer volume flow is controlled via a first proportional spool valve 4 and a first selector valve 6. For this, the first control device 2 is supplied with pump pressure via a common pressure channel P.

(3) In the illustrated first switching position a of the first selector valve 6, a first group of hydraulic consumers connected to the hydraulic consumer ports A1, A2 can be actuated via a corresponding displacement of the first proportional spool valve 4. Depending on the displacement of the first proportional spool valve 4, the hydraulic consumer port A1 or A2 is pressurized from the pressure channel P or relieved to the tank via a return channel R. By switching the first selector valve 6 to the second switching position b, a second group of hydraulic consumers connected to the hydraulic consumer ports B1, B2 can be actuated accordingly.

(4) Accordingly, the second control device 3 also has four hydraulic consumer ports A3, A4, B3, and B4 as well as a second proportional spool valve 5 and a second selector valve 7. The function of the second control device 3 is the same as that of the first control device 2. When the second selector valve 7 is, as shown, in the first switching position c, a first group of hydraulic consumers connected to the hydraulic consumer ports A3, A4 can be actuated. By switching the second selector valve 7 to the second switching position d, a second group of hydraulic consumers connected to the hydraulic consumer ports B3, B4 can be actuated accordingly.

(5) The first group of hydraulic consumers connected to the hydraulic consumer ports A1, A2, A3 and A4 can be designed, for example, to control the supports of a mobile crane. Therefore, the hydraulic consumers of the second group connected to the hydraulic consumer ports B1, B2, B3 and B4 can be designed, for example, to control the mast of the mobile crane. To switch between the groups to be actuated, the first selector valve 6 and the second selector valve 7 are each designed as spool valves, in particular as 10/2 spool valves.

(6) In order to prevent the simultaneous actuation of hydraulic consumers of the first and second group due to a malfunction of the first selector valve 6 or the second selector valve 7, hydraulic valve assembly 1 has a forced circuit. For this purpose, a pressure pilot-controlled shut-off valve 9 is provided in the common pressure channel P upstream of the first and second proportional spool valves 4, 5 to interrupt the pressure supply of the first control device 2 and the second control device 3. The shut-off valve 9 acts as a pressure channel shut-off and is spring-loaded in the shut-off direction by a spring 19 and can be pressurized in the opening direction by a control channel 8.

(7) There is pressure in control channel 8 when the first selector valve 6 and the second selector valve 7 are each in the same switching position, that means when both selector valves 6, 7 are either both in the first switching position a, c or both in the second switching position b, d. For this purpose, a branch channel 10 branches off from the pressure channel P upstream of the shut-off valve 9. Branch channel 10 is divided, as shown, into a first pressure branch channel 11 and a second pressure branch channel 12. If the first selector valve 6 is, as shown, in the first switching position a, the first pressure branch channel 11 is connected to a first connection line 13. The second pressure branch channel 12 is blocked in the first switching position a of the first selector valve 6.

(8) Accordingly, the first connection line 13 in the first switching position c of the second selector valve 7 is connected to control channel 8 so that the pressure applied to the branch channel 10 via control channel 8 keeps the shut-off valve 9 open against the spring force of the spring 19. If the first selector valve 6 and the second selector valve 7 are now each switched to the second switching position b, d, the first selector valve 6 connects the second pressure branch channel 12 with a second connection line 14. The first pressure branch channel 11 is blocked at the first selector valve 6. The second connection line 14 is then connected to the control channel 8 via the second selector valve 7, while the first connection line 13 is blocked at the second selector valve 7.

(9) If the first selector valve 6 and the second selector valve 7 are not in the same switching position, branch channel 10 is not connected to control channel 8. In this case, the shut-off valve 9 moves to the shut-off position due to the spring force of the spring 19. In order to relieve the possibly existing pressure in control channel 8, a relief line 15 branches off from control channel 8 and flows into return channel R. A hydraulic resistor in the form of a throttle 16 is arranged in relief line 15. Via this defined relief of the control channel 8 into the return channel R, the remaining residual pressure in the control channel 8 is reduced so that a safe response or switching of the shut-off valve 9 is guaranteed. It is, of course, also conceivable in this context that throttle 16 is designed as an adjustable throttle.

(10) For safety reasons, the shut-off valve 9 is designed as a seated valve. Thus, the shut-off valve 9 is not designed as a spool valve like the first and second selector valves 6, 7. In order to further prevent a malfunction of the shut-off valve 9, a filter 18 is arranged in branch 10.

(11) In addition, a closing valve 17 is arranged in control channel 8 upstream of the branch of the relief line 15. The closing valve 17 has an electromagnet 22 acting in the opening direction which holds the closing valve 17 open against the spring force of a spring 20 when energized. The current supply to the electromagnet 22 can be interrupted manually so that the closing valve 17 closes control channel 8 due to the spring force of spring 20. Consequently, the residual pressure is relieved via the relief line 15 to the return channel R and the shut-off valve 9 interrupts the pressure supply to the first and second control devices 2, 3. Closing valve 17 thus represents an easy-to-implement “emergency stop”. In addition, there is also the advantage that in the event of a power failure of the mobile hydraulics, the closing valve 17 also closes control channel 8, thus interrupting the pressure supply to the first control device 2 and the second control device 3.

(12) In the embodiment shown in the FIGURE, the first selector valve 6 and the second selector valve 7 are actuated via corresponding electromagnets. The electromagnets are controlled via a coupling 25, which is indicated as a dotted line in the FIGURE. Thus, the first selector valve 6 is always switched synchronously with the second selector valve 7. It is of course also conceivable that the coupling 25 is a mechanical or hydraulic coupling.

(13) As shown, the hydraulic valve assembly 1 has a modular design and can therefore be extended accordingly. In particular, it is evident that the first control device 2 and the second control device 3 are completely identical. The first control device 2 and the second control device 3 are designed as valve segments which together with a connection block 23 and an end plate 24 form the hydraulic valve assembly 1. The shut-off valve 9, the branch channel 10 and the closing valve 17 are arranged in connection block 23. In addition, a pressure relief valve 21 is arranged in connection block 23, which relieves the pressure channel P to the return channel R at a certain limit pressure. The end plate 24 serves to connect the corresponding lines of the second control device 3 to the control channel 8.

(14) Thus, the inventive hydraulic valve assembly 1 can easily be supplemented by further control devices. Furthermore, the disclosure is not limited to the fact that only two groups of hydraulic consumers can be actuated. Three or more groups of hydraulic consumers can also be actuated. For this purpose, the selector valves may then be designed with a corresponding number of switching positions and the corresponding number of pressure branch channels may be provided. In other words, if three groups of hydraulic consumers are to be controlled, the selector valves may be designed with three switching positions and three pressure branch channels may be provided.