Valve arrangement for controlling at least one connection of a hydraulic consumer

Abstract

The invention relates to a valve assembly for controlling at least one connection of a hydraulic load, comprising a valve housing with at least one valve integrated therein, said valve preferably being in the form of a proportional valve, wherein the valve housing has at least a load connection for a working line leading to the load, a supply connection for connecting to a pressure source and an outlet / tank connection for connecting to a tank, and wherein, for each valve, a control slide is slidably provided in the valve housing. In order to provide an improved valve assembly, at least for one valve integrated in the valve assembly all primary and secondary hydraulic functions to be provided for the control of the load to be controlled by means of said valve, such as open-loop volumetric flow rate control and / or closed-loop volumetric flow rate control and / or local pressure limitation and / or shock suctioning and / or non-return function and / or load pressure signal acquisition, are integrated into the control slide of said valve.

Description

[0001] Valve arrangement for controlling at least one connection of a hydraulic consumer

[0002] The invention relates to a valve arrangement for controlling at least one connection of a hydraulic consumer, comprising a valve housing with at least one valve integrated therein, preferably designed as a proportional valve, wherein the valve housing has at least one consumer connection for a working line leading to the consumer, a supply connection for connection to a pressure source and a drain / tank connection for connection to a tank, wherein a control slide is provided for each valve in a displaceable manner in the valve housing.

[0003] Such valve arrangements are known in practice in many different designs, in which the valve housing is very complex and therefore has correspondingly large geometric dimensions.

[0004] The object of the invention is to avoid the aforementioned disadvantages and to provide an improved valve arrangement with which a simpler and smaller dimensioned valve arrangement can be realized.

[0005] This object is achieved in a generic valve arrangement in that, for at least one valve integrated into the valve arrangement, all of the main and secondary hydraulic functions required to control the consumer to be controlled by this valve, such as volume flow control and / or volume flow regulation and / or local pressure limitation and / or shock absorption and / or check function and / or load pressure signal detection, are each integrated into the respective control spool of this valve. The simplest embodiment is then a plunger cylinder, which has only one connection for movement in one direction, e.g., extension, and in which movement in the other direction is effected by an external force such as spring force or gravity.

[0006] The primary functions can be, for example, volume flow control and / or volume flow regulation, whereas secondary functions can be, for example, local pressure limitation and / or shock recovery and / or check valve function and / or load pressure signal detection. Other possible secondary functions can be pressure relief and / or pressure reduction function and / or signal manipulation.

[0007] By integrating primary and secondary hydraulic functions into the respective control spool of a valve, for example, the number of required bores can be reduced, and simpler casting patterns for the valve housing are possible. This reduces the complexity of the valve housing and the geometric dimensions. Furthermore, cost savings are achieved through simpler components on the one hand and the substitution of components on the other, for example, in the implementation of the shock absorption function.

[0008] The consumer can, for example, be a hydraulic cylinder, whereby the design can be, for example, a differential cylinder, a synchronous cylinder or a telescopic cylinder.

[0009] Preferably, at least one valve provided in the valve housing can comprise a shock refill valve and / or at least one pressure compensator with a blocking function and / or at least one pressure relief valve, thus implementing the corresponding functionalities for this valve. According to the invention, at least one valve provided in the valve housing can be designed as a 3-way proportional valve for displacement control or as a 4-way proportional valve with an additional signal connection for use in load-sensing operation.

[0010] Advantageously, at least one control slide provided in the valve housing can have three positions (0, 1 and 2) which can be approached proportionally or by switching.

[0011] In a first position ("position O" = middle position) of at least one control spool, preferably each control spool, the corresponding consumer connection can be connected to the drain / tank connection via a shock suction valve and the supply connection can not be connected to the corresponding consumer connection or to the drain / tank connection.

[0012] Furthermore, two proportional valves can be provided in the valve housing and each designed as a 4-3-way proportional valve, wherein in the first position ("position O" = middle position) of at least one control spool, preferably each control spool, the corresponding signal connection is separated from the corresponding consumer connection as well as from the supply connection and the drain ZTank connection.

[0013] In addition, in a second position ("position 1") of at least one control spool, preferably each control spool, the corresponding consumer connection can be connected on the one hand via a shock re-cavitation valve to the drain ZTank connection and on the other hand via an upstream pressure compensator integrated into the control spool to the supply connection.

[0014] The pressure compensator can be equipped with a blocking function in the direction of the supply connection. Preferably, the two proportional valves can each be designed as 4-3-way proportional valves, and in the second position ("position 1") of the respective control spool, the corresponding consumer connection can be connected to the signal connection for use in load-sensing operation to transmit the pressure level at the consumer connection to the signal connection.

[0015] Furthermore, in a third position ("position 2") of the respective control spool, the corresponding consumer connection can be connected to the drain / tank connection via a shock refill valve, wherein a pressure limiting function can also be provided, which is effected by the shock refill valve or a pressure limiting valve provided between the corresponding consumer connection and the drain / tank connection parallel to the shock refill valve and integrated into the control spool, wherein the supply connection is not connected to the corresponding consumer connection or to the drain / tank connection.

[0016] Preferably, the two proportional valves can each be designed as 4-3-way proportional valves, and the corresponding consumer port is not connected to the signal port for use in load-sensing mode when the corresponding control spool is in the third position ("position 2"). In this case, the flow direction from the corresponding consumer port to the signal port for use in load-sensing mode can be blocked.

[0017] According to the invention, at least one control slide provided in the valve housing can have a through bore, wherein this control slide can preferably be made from a pipe section.

[0018] In a preferred embodiment of the invention, the valve arrangement can comprise a pressure relief valve and a shock absorption valve, wherein the pressure relief valve comprises a spring preload sleeve, a pressure relief valve piston, and a pressure relief valve spring arranged between the spring preload sleeve and the pressure relief valve piston. Furthermore, the shock absorption valve comprises a stop piston, a sealing piston, and a return spring arranged between the stop piston and the sealing piston. The sealing piston has a through-bore, preferably tapering toward the through-bore, and cooperates with a control piston at its end facing away from the return spring. The control piston, in turn, can be connected to the corresponding consumer connection.

[0019] Advantageously, the existing valves can be designed modularly. This allows the functions of the valve assembly to be adapted by omitting components (e.g., pressure compensator, check valve in the pressure relief valve) or modifying them (e.g., spring preloads) without requiring modifications to the valve housing.

[0020] The invention further relates to a hydraulic system with at least one valve arrangement and at least one hydraulic consumer controlled thereby. The disadvantages of previously known valve arrangements have already been discussed above.

[0021] For an improved hydraulic system, at least two valve arrangements according to the invention are to be provided and the hydraulic system is to be a hydraulic system with resolved control edges.

[0022] Alternatively, the hydraulic system may also have at least two valve arrangements according to the invention and be operable in 4-quadrant operation.

[0023] The following are exemplary embodiments of the invention illustrated in circuit diagrams in the drawings. They show:

[0024] Fig. 1 is a circuit diagram of a valve arrangement according to the invention, Fig. 2 is a circuit diagram of a first embodiment of a hydraulic system according to the invention with a valve arrangement according to the invention,

[0025] Fig. 3 is a circuit diagram of a second embodiment of a hydraulic system according to the invention with a valve arrangement according to the invention and

[0026] Fig. 4 is a sectional view of the article according to Fig. 1.

[0027] In all figures, identical reference symbols are used for identical or similar components.

[0028] Fig. 1 shows, in the form of a hydraulic circuit diagram, a valve arrangement 1 for controlling a connection 2 of a hydraulic consumer 3 not shown in Fig. 1. The valve arrangement 1 comprises a valve housing 4, not shown in detail in the illustrations, with a valve 5 integrated therein, designed as a proportional valve in the example shown.

[0029] The valve housing 4 has a consumer connection 6 for a working line 7 (not shown in Fig. 1) leading to the consumer 3, a supply connection 8 for connection to a pressure source (not shown in the illustrations), and a drain tank connection 9 for connection to a tank, wherein a control slide 10 is provided for the valve 5 so as to be displaceable in the valve housing 4.

[0030] All main and secondary hydraulic functions required for controlling the consumer to be controlled by the valve 5 are integrated into the control spool 10 of this valve 5.

[0031] The valve 5 provided in the valve housing 4 comprises a pressure compensator 11 with a blocking function and a pressure relief valve 12, thus implementing the corresponding functionalities for the valve 5. The valve 5 is designed as a 4-3-way proportional valve with an additional signal connection 13 for use in load-sensing operation.

[0032] The control slide 10 provided in the valve housing 4 has three positions (0, 1 and 2) which can be approached proportionally.

[0033] In Fig. 2, a first embodiment of a hydraulic system 14 according to the invention with a valve arrangement 1 according to the invention and a hydraulic consumer 3 is shown as a hydraulic circuit diagram.

[0034] Fig. 3 shows a second embodiment of a hydraulic system 14 according to the invention with two valve assemblies 1 according to the invention and a hydraulic consumer 3 as a hydraulic circuit diagram. Two proportional valves are provided in the valve housing, each designed as a 4-3-way proportional valve.

[0035] In the first position ("position O" = middle position) of the two control spools 10 shown in the figures, the respective signal connection 13 is separated from the respective consumer connection 6 as well as from the supply connection 8 and the drain / tank connection 9.

[0036] For each control spool 10, the corresponding consumer port 6 is connected to the drain / tank port 9 via a shock suction valve 15.

[0037] In the second position ("position 1") not shown in the figures, the corresponding consumer connection 6 of each control spool 10 is connected on the one hand to the drain / tank connection 9 via a shock suction valve 15 and on the other hand to the supply connection 8 via an upstream pressure compensator 11 integrated into the control spool.

[0038] In addition, the corresponding consumer connection 6 is connected to the signal connection 13 for use in load-sensing operation to transmit the pressure level at the consumer connection 6 to the signal connection 13.

[0039] In the third position ("position 2") of the respective control spool 10, not shown in the figures, the corresponding consumer port 6 is connected to the drain / tank port 9 via a shock refill valve 15. A pressure relief function is also provided, which is effected by the shock refill valve 15 or a pressure relief valve 12 provided between the corresponding consumer port 6 and the drain / tank port 9, parallel to the shock refill valve 15 and integrated into the control spool. The supply port 8 is not connected to the corresponding consumer port 6 or to the drain / tank port 9.

[0040] In the third position ("position 2") of the corresponding control spool 10, the corresponding consumer port 6 is also not connected to the signal port 13 for use in load-sensing mode. The flow direction from the corresponding consumer port 6 to the signal port 13 for use in load-sensing mode is thus blocked.

[0041] As can be seen from Fig. 4, the control slide 10 provided in the valve housing 4 has a through bore and can therefore be made from a pipe section.

[0042] The valve assembly 1 shown comprises a pressure relief valve 12 and a shock recovery valve 15, wherein the pressure relief valve 12 comprises a spring preload sleeve 18, a pressure relief valve piston 19, and a pressure relief valve spring 20 arranged between the spring preload sleeve 18 and the pressure relief valve piston 19. The end of the pressure relief valve piston 19 facing away from the pressure relief valve spring interacts with a spring 25.

[0043] The shock refill valve 15 comprises a stop piston 21, a sealing piston 22, and a return spring 23 arranged between the stop piston 21 and the sealing piston 22. The sealing piston 22 has a through-bore tapering in the direction of the through-bore and the return spring 23 and interacts with a control piston 24 at its end facing away from the return spring 23. The control piston 24, in turn, is connected to the corresponding consumer connection 6.

[0044] When the pressure level in the tank 16 becomes greater than the pressure level in the consumer connection 6 plus the spring force of the return spring 23, the sealing piston 22 moves in the direction of the stop piston 21 and enables a connection from the drain tank connection 9 to the consumer connection 6 and thus realizes the suction function.

[0045] The shock function of the pressure relief valve 12 occurs when a pressure set by the pressure relief valve spring 20 in the consumer port 6 is exceeded, in which the pressure relief valve piston 19 then lifts off the stop piston 21. The same pressure level exists in the spring chamber as in the drain Z-tank port 9, so that the pressure level between the stop piston 21 and the sealing piston 22 becomes lower than the pressure level in the consumer port 6. The sealing piston 22 thus moves towards the stop piston 21, thus enabling pressure reduction from the consumer port 6 to the drain Z-tank port 9.

[0046] For the pressure relief function of the pressure relief valve 12, the control piston 24, paired with an associated discharge edge, enables a nearly constant pressure in the consumer port 6. The pressure level is largely determined by the spring 25 and the front surface of the control piston 24. This makes it possible, regardless of the inlet position of the control spool 10 (spool position "1"), to move the control spool 10 to the end position and always maintain a defined pressure level in the consumer port 6. In this respect, the consumer 3 cannot cavitate during a load change, for example, from pulling loads to pushing loads.

[0047] When the control spool 10 is moved toward switching position "1" and a correspondingly provided control edge 26 then releases a flow area, the pressure compensator 11 regulates a nearly constant pressure drop across a control edge 26 of a control edge bore 30. The pressure drop corresponds to the spring force of the spring 25 relative to the front surface of the pressure compensator 11. The control stroke of the pressure compensator 11 is defined by a position disc 27 and a spring carrier 28. The position disc 27 also ensures that the pressure compensator 11 is held within a defined range of the control spool 10.

[0048] The pressure compensator 11 comprises a pressure compensator piston 29, which provides the blocking function from the consumer port 6 to the supply port 8. When the pressure level in the consumer port 6 becomes greater than the pressure level in the supply port 8, the pressure compensator piston 29 moves and closes the control edge bore 30 in the control spool 10, thus blocking the backflow from the consumer port 6 to the supply port 8.

Claims

Claims 1. Valve arrangement (1) for controlling at least one connection (2) of a hydraulic consumer (3), comprising a valve housing (4) with at least one valve (5) integrated therein, preferably designed as a proportional valve, wherein the valve housing (4) has at least one consumer connection (6) for a working line (7) leading to the consumer (3), a supply connection (8) for connection to a pressure source and a drain / tank connection (9) for connection to a tank, wherein for each valve (5) a control slide (10) is provided displaceably in the valve housing (4), characterized in that at least for one valve (5) integrated in the valve arrangement (1), all hydraulic main and secondary functions to be provided for controlling the consumer (3) to be controlled by this valve (5), such as e.g.Volume flow control and / or volume flow regulation (on the one hand) and / or local pressure limitation and / or shock absorption and / or check function and / or load pressure signal detection (on the other hand), the necessary components are each integrated into the respective control spool (10) of this valve (5).

2. Valve arrangement (1) according to the preceding claim, characterized in that at least one valve (5) provided in the valve housing (4) comprises a shock absorption valve (15) and / or at least one pressure compensator (11) with a blocking function and / or at least one pressure relief valve (12).

3. Valve arrangement (1) according to one of the preceding claims, characterized in that at least one valve (5) provided in the valve housing (4) is designed as a 3-way proportional valve for displacement control or as a 4-3-way proportional valve with an additional signal connection (13) for use in load-sensing operation.

4. Valve arrangement (1) according to one of the preceding claims, characterized in that at least one control slide (10) provided in the valve housing (4) has three positions (0, 1 and 2) which can be approached proportionally or by switching.

5. Valve arrangement (1) according to the preceding claim, characterized in that in a first position ("position O" = middle position) of at least one control slide (10), preferably each control slide (10), the corresponding consumer connection (6) is connected to the drain / tank connection (9) via a shock suction valve (15) and the supply connection (8) is not connected to the corresponding consumer connection (6) and also not to the drain / tank connection (9).

6. Valve arrangement (1) according to claim 4 or 5, characterized in that two valves (5) are provided in the valve housing (4) and are each designed as 4-3-way proportional valves, wherein in the first position ("position O" = middle position) of at least one control slide (10), preferably each control slide (10), the corresponding signal connection (13) is separated from the corresponding consumer connection (6) as well as from the supply connection (8) and the drain / tank connection (9).

7. Valve arrangement (1) according to one of claims 4 to 6, characterized in that in a second position ("position 1") of at least one control slide (10), preferably each control slide (10), the corresponding consumer connection (6) is connected on the one hand via a shock suction valve (15) to the drain / tank connection (9) and on the other hand via an upstream pressure compensator (11) integrated in the corresponding control slide (10) to the supply connection (8).

8. Valve arrangement (1) according to the preceding claim, characterized in that the pressure compensator (11) is provided with a blocking function in the direction of the supply connection (8).

9. Valve arrangement (1) according to one of claims 4 to 8, characterized in that the two proportional valves are each designed as 4-3-way proportional valves and in the second position ("position 1") of the respective control slide (10) the corresponding consumer connection (6) is connected to the signal connection (13) for use in load-sensing operation for forwarding the pressure level at the consumer connection (6) to the signal connection (13).

10. Valve arrangement (1) according to one of claims 4 to 9, characterized in that in a third position ("position 2") of the respective control slide (10), the corresponding consumer connection (6) is connected to the drain / tank connection (9) via a shock refill valve (15), wherein a pressure limiting function is also provided, which is effected by the shock refill valve (15) or a pressure limiting valve (12) provided between the corresponding consumer connection (6) and the drain / tank connection (9) parallel to the shock refill valve (15) and integrated into the control slide (10), wherein the supply connection (8) is not connected to the corresponding consumer connection (6) or to the drain / tank connection (9).

11. Valve arrangement (1) according to the preceding claim, characterized in that the two proportional valves are each designed as 4-3-way proportional valves and the corresponding consumer connection in the third position ("position 2") of the corresponding control slide (10) is not connected to the signal connection (13) for use in load-sensing operation.

12. Valve arrangement (1) according to one of the preceding claims, characterized in that at least one control slide (10) provided in the valve housing (4) has a through bore.

13. Valve arrangement (1) according to the preceding claim, characterized in that the control slide (10) is made from a pipe section.

14. Valve arrangement (1) according to one of the preceding claims, characterized in that the valve arrangement (1) comprises a pressure relief valve (12) and a shock absorption valve (15), wherein the pressure relief valve (12) comprises a spring preloading sleeve (18), a pressure relief valve piston (19) and a pressure relief valve spring (20) arranged between the spring preloading sleeve (18) and the pressure relief valve piston (19), and wherein the shock absorption valve (15) further comprises a stop piston (21), a sealing piston (22) and a return spring (23) arranged between the stop piston (21) and the sealing piston (22), and the sealing piston (22) has a through-bore, preferably tapering in the direction of the through-bore and the return spring (23), and cooperates with a control piston (24) with its end facing away from the return spring (23).

15. Valve arrangement (1) according to one of the preceding claims, characterized in that the existing valves (5) are of modular construction.

16. Hydraulic system with at least one valve arrangement (1) and at least one hydraulic consumer (3) which can be controlled thereby, characterized in that the hydraulic system has at least two valve arrangements (1) according to one of the preceding claims and is a hydraulic system with resolved control edges.

17. Hydraulic system with at least one valve arrangement (1) and at least one hydraulic consumer (3) which can be controlled thereby and has at least two connections (2), characterized in that the hydraulic system has at least two valve arrangements (1) according to one of claims 1 to 16 and can be operated in 4-quadrant operation.