Multi-stage pressure compensation proportional reversing valve group

Abstract

The utility model relates to the technical field of fluid pressure executing mechanisms, in particular to a multi-stage pressure compensating proportional reversing valve group which comprises a pressure compensating valve, a pressure regulating valve and a pressure regulating valve. An oil inlet of the proportional reversing valve is connected with an oil outlet of an external pipeline through a pressure compensation valve, two working oil ports of the proportional reversing valve are connected with working oil ports of an external hydraulic actuating mechanism through two oil ways respectively, and a shuttle valve is arranged between the two oil ways; a working oil port of the overflow valve assembly is connected with the shuttle valve, an oil inlet of the overflow valve assembly is connected with a control port of the pressure compensation valve and an oil inlet of an external pipeline, an oil return port of the overflow valve assembly is connected with an oil return port of the external pipeline, and the overflow valve assembly is used for adjusting the pressure difference between the front portion and the rear portion of the proportional reversing valve. The overflow valve assembly is arranged between the pressure compensation mechanism and the executing mechanism, and the maximum flow capacity of the proportional reversing valve in the system is changed through combined use of the overflow valve and the reversing valve.

Description

Technical Field

[0001] The present application relates to the technical field of fluid pressure actuators, and in particular to a proportional reversing valve group with multi-stage pressure compensation. Background Art

[0002] Pressure compensation valve is mainly used in proportional servo system, and is used in conjunction with shuttle valve to adjust the pressure difference between the inlet and outlet of proportional reversing valve to always keep a constant value, so that the flow output of proportional reversing valve is more stable. Figure 1 shown.

[0003] Figure 1 In the diagram, the setting value of pressure compensating valve 1 is usually fixed, assuming it is set to 10 bar; shuttle valve 3 selects the highest pressure of oil outlets A and B of proportional reversing valve 2, and the control oil port of pressure compensating valve 1 is connected to the outlet of shuttle valve 3. Regardless of changes in system pressure or load, pressure compensating valve 1 can maintain the pressure difference between the inlet and outlet of proportional reversing valve 2 at a constant value of 10 bar.

[0004] In the existing pressure-compensating valve structure, the pressure of the pressure-compensating valve 2 is a fixed value, and the pressure difference before and after the proportional reversing valve 2 is a fixed value. The maximum flow rate of the proportional reversing valve 2 of the same specification is fixed. If a larger flow rate is required, it is necessary to change the specification of the proportional reversing valve 2 or increase the set value of the pressure-compensating valve. For example, if a 10-bar pressure-compensating valve is changed to a 20-bar one, the maximum flow rate of the proportional reversing valve will also double, but the required pressure of the P port, that is, the total power of the hydraulic system, will increase, and the cost will increase significantly. Utility Model Content

[0005] The technical problem to be solved by the utility model is that the maximum flow rate of the existing pressure compensation valve structure is difficult to adjust.

[0006] To this end, the utility model provides a proportional reversing valve group with multi-stage pressure compensation.

[0007] The technical solution adopted by the utility model to solve its technical problems is:

[0008] A multi-stage pressure-compensated proportional reversing valve group, comprising:

[0009] a pressure compensating valve, wherein the oil inlet of the pressure compensating valve is connected to an external pipeline;

[0010] A proportional reversing valve, wherein the oil inlet of the proportional reversing valve is connected to the oil outlet of an external pipeline through a pressure compensating valve, and the two working oil ports of the proportional reversing valve are respectively connected to the working oil ports of an external hydraulic actuator through two oil circuits, with a shuttle valve provided between the two oil circuits;

[0011] A relief valve assembly, wherein the working oil port of the relief valve assembly is connected to the shuttle valve, the oil inlet of the relief valve assembly is connected to the control port of the pressure compensation valve and the oil inlet of the external pipeline, the oil return port of the relief valve assembly is connected to the oil return port of the external pipeline, and the relief valve assembly is used to adjust the pressure difference before and after the proportional reversing valve.

[0012] Furthermore, a throttle is connected between the overflow valve assembly, the control port of the pressure compensation valve, and the oil inlet of the external pipeline.

[0013] Furthermore, the overflow valve assembly includes two overflow valves and an electromagnetic reversing valve, the oil inlet of the electromagnetic reversing valve is connected to the control port of the pressure compensation valve and the oil inlet of the external pipeline, the oil outlet of the electromagnetic reversing valve is connected to the return oil port of the external pipeline, the two overflow valves are respectively connected between the shuttle valve and the electromagnetic reversing valve through two independent pipelines, and the two overflow valves are respectively connected to the two working oil ports of the electromagnetic reversing valve.

[0014] Furthermore, the two relief valves are respectively the first relief valve and the second relief valve, and their setting values are respectively P m1 and P m2 , P m1 ≠P m2 .

[0015] Furthermore, the throttle is connected between the control ports of the electromagnetic reversing valve and the pressure compensation valve and the oil inlet of the external pipeline.

[0016] Furthermore, when the electromagnetic reversing valve is not energized, the second overflow valve is connected to the return oil port of the external pipeline, and the oil inlet of the first overflow valve is connected to the control port of the pressure compensation valve through the throttle on the one hand, and to the oil inlet of the external pipeline through the throttle on the other hand.

[0017] Furthermore, if the system sets the load pressure to PL, the initial spring force of the pressure compensation valve to PK, when the solenoid reversing valve is de-energized, the initial pressure of the oil inlet of the solenoid reversing valve is P2 = PL + P m1 The set value of the pressure compensation valve and the proportional reversing valve oil inlet pressure P1 = P2 + PK = PL + P m1 +PK, pressure difference before and after the proportional reversing valve ΔP=P m1 +PK.

[0018] Furthermore, when the electromagnetic reversing valve is energized, the first overflow valve is connected to the return oil port of the external pipeline, and the oil inlet of the second overflow valve is connected to the control port of the pressure compensation valve through the throttle on the one hand, and to the oil inlet of the external pipeline through the throttle on the other hand.

[0019] Furthermore, if the system sets the load pressure to PL, the initial spring force of the pressure compensation valve is PK, when the solenoid reversing valve is energized, the initial pressure of the oil inlet of the solenoid reversing valve is P2 = PL + P m2 The set value of the pressure compensation valve and the proportional reversing valve oil inlet pressure P1 = P2 + PK = PL + P m2 +PK, pressure difference before and after the proportional reversing valve ΔP=P m2 +PK.

[0020] Furthermore, the relief valve assembly includes a proportional relief valve, the working oil port of the proportional relief valve is connected to the shuttle valve, and the oil inlet of the proportional relief valve is connected to the control port of the pressure compensation valve and the oil inlet of the external pipeline.

[0021] The beneficial effect of the present invention is that the present application arranges an overflow valve assembly between the pressure compensation and the actuator, and the pressure compensation valve is used in combination with the overflow valve and the reversing valve to change the maximum flow capacity of the proportional reversing valve in the system. Compared with replacing a proportional reversing valve with a large diameter, the cost is much saved and multi-stage adjustment of the maximum flow rate can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 It is a structural diagram of a pressure compensation valve in the prior art.

[0024] Figure 2 It is a structural diagram of the pressure compensation valve group in Example 1 of the present application.

[0025] Figure 3 It is a structural diagram of the pressure compensation valve group in Example 2 of the present application.

[0026] In the figure: 1. Proportional reversing valve; 2. Pressure compensating valve; 3. Shuttle valve; 4. Throttle; 5. Overflow valve assembly; 51. Solenoid reversing valve; 52. Overflow valve; 521. First overflow valve; 522. Second overflow valve; 53. Proportional overflow valve. DETAILED DESCRIPTION

[0027] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0029] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0030] Example 1

[0031] A multi-stage pressure-compensated proportional reversing valve group includes a pressure-compensating valve 2, a proportional reversing valve 1, a shuttle valve 3, and a relief valve assembly 5. The multi-stage pressure-compensated proportional reversing valve group is connected between an external pipeline and a power actuator to achieve communication between the hydraulic oil in the external pipeline and the power actuator oil circuit, so as to control the output conditions of the power actuator under different working conditions.

[0032] The pressure compensating valve 2 is connected to an external pipeline, the shuttle valve 3 is connected to a power actuator, and the proportional reversing valve 1 is connected between the pressure compensating valve 2 and the shuttle valve 3 .

[0033] Specifically, refer to Figure 2 , Figure 2 In the figure, P represents the oil outlet, T represents the oil return port, A and B are the working oil ports, the oil inlet of the external pipeline is connected to the oil inlet of the proportional reversing valve 1 through the pressure compensation valve 2, the oil return port of the proportional reversing valve 1 is connected to the oil return port of the external pipeline, the two working oil ports on the proportional reversing valve 1 are connected to the two working oil ports on the power actuator through two oil circuits respectively, and a shuttle valve 3 is provided between the two oil circuits.

[0034] The working oil port of the relief valve assembly 5 is connected to the shuttle valve 3 , and the relief valve assembly 5 is used to adjust the pressure difference before and after the proportional reversing valve 1 .

[0035] In this embodiment, the overflow valve assembly 5 includes two overflow valves 52 and an electromagnetic reversing valve 51. The oil inlet of the electromagnetic reversing valve 51 is connected to two oil circuits, one oil circuit is connected to the control port of the pressure compensation valve 2, and the other is connected to the oil inlet of the external pipeline. A throttle 4 is provided on both oil circuits; the oil return port of the electromagnetic reversing valve 51 is connected to the oil return port of the external pipeline.

[0036] The two relief valves 52 are respectively connected between the shuttle valve 3 and the electromagnetic reversing valve 51 through two independent pipelines. The two relief valves 52 are respectively connected to the two working oil ports of the electromagnetic reversing valve 51.

[0037] The implementation principles of this application are:

[0038] The hydraulic oil of the external pipeline is supplied from the P port (P in the figure). a ) through the pressure compensation valve 2 to the P port of the proportional reversing valve 1 (P in the figure b ), by giving different signals to the proportional reversing valve 1, the speed of the cylinder extending and retracting can be controlled.

[0039] The working process of pressure compensation valve 2 is: set the load pressure to PL, the pressure of the external pipeline oil inlet to P0, and the oil inlet of proportional reversing valve 1 to P b The pressure is P1, the oil inlet of the electromagnetic reversing valve 51 (indicated as P in the figure) c ) pressure is P2, the initial spring force of the pressure compensation valve 2 is PK, the two relief valves 52 are the first relief valve 521 and the second relief valve 522, and their setting values are P m1 and P m2 In this embodiment, P is set m1 10 bar, P m2 The set value is 20bar, and the set value can be adjusted according to actual needs.

[0040] When the electromagnetic reversing valve 51 is not powered, the oil return port of the relief valve 52 is directly connected to the oil return port T of the external pipeline. a The oil inlet of the overflow valve 52 is connected to the control port of the pressure compensation valve 2 through the throttle 4, and is connected to the oil inlet P of the external pipeline through the throttle 4. a pressure oil passes through the throttle 4 and the solenoid reversing valve 51 to the oil inlet of the relief valve 52, the load pressure passes through the shuttle valve 3 to the outlet of the relief valve 52, since the first relief valve 521 is set to P m1 , so the solenoid reversing valve 51P c Pressure P2=PL+P m1 The control port of the pressure compensation valve 2 is connected to the throttle 4 and the electromagnetic reversing valve 51P.c The ports are connected, so the setting value of the pressure compensation valve 2 (i.e. the oil inlet port P of the proportional reversing valve 1) b Pressure P1), P1=P2+PK=PL+P m1 +PK, pressure difference before and after proportional reversing valve 1 ΔP=P m1 +PK;

[0041] Similarly, after the electromagnetic reversing valve 51 is energized and reversed, the first relief valve 521 is connected to the oil return port of the external pipeline, and the oil inlet of the second relief valve 522 is connected to the control port of the pressure compensation valve 2 through the throttle 4 on the one hand, and to the oil inlet of the external pipeline through the throttle 4 on the other hand. At this time, the second relief valve 522 is in effect, and the pressure difference before and after the proportional reversing valve 1 is ΔP=P m2 +PK; the pressure difference before and after the proportional reversing valve 1 increases, and its maximum flow capacity also increases.

[0042] During the operation of the above-mentioned pressure compensating valve 2, since the two relief valves 52 control different set values of the pressure compensating valve 2, the electromagnetic reversing valve 51 is used to switch different relief valves 52 to adjust the set value of the pressure compensating valve 2, thereby changing the pressure difference before and after the proportional reversing valve 1 to increase or decrease the maximum flow rate of the proportional reversing valve 1, thereby achieving the function of adjusting the maximum flow capacity of the proportional reversing valve 1 to meet the actuator speed requirements under different working conditions.

[0043] Example 2

[0044] In this embodiment, the overflow valve assembly 5 includes a proportional overflow valve 53, and its working process is similar to the principle in Example 1, which will not be elaborated here. The difference from the above principle is that the proportional overflow valve 53 can steplessly adjust the set pressure of the pressure compensation valve 2. In actual use, the stepless adjustment function is rarely used. Generally, several pressure levels are set for the proportional overflow valve 53 to meet the needs of different working conditions.

[0045] To summarize, the present application changes the maximum flow capacity of the proportional reversing valve 1 in the system by setting a relief valve assembly 5 between the pressure compensation and the actuator, and the pressure compensation valve 2 is used in combination with the relief valve 52 and the reversing valve. Compared with replacing the proportional reversing valve 1 with a large diameter, it saves a lot of costs and can achieve multi-stage adjustment of the maximum flow rate.

[0046] The design scheme of this application is mainly used in situations where both high load and slow speed and low load and high speed are required at the same time, especially when the pressure difference before and after the proportional reversing valve 1 remains unchanged and cannot meet the requirements of both speeds at the same time. The scheme mentioned in this patent can be used, which does not require replacing a larger proportional reversing valve 1, nor does it require increasing the total power of the system, saving costs and allowing online pressure switching.

[0047] Based on the above-described preferred embodiments of the present invention, and in accordance with the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of the present invention. The technical scope of the present invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A multi-stage pressure-compensated proportional reversing valve group, characterized in that: include, A pressure compensating valve (2), wherein the oil inlet of the pressure compensating valve (2) is connected to an external pipeline; A proportional reversing valve (1), wherein the oil inlet of the proportional reversing valve (1) is connected to the oil outlet of an external pipeline via a pressure compensation valve (2), and the two working oil ports of the proportional reversing valve (1) are respectively connected to the working oil ports of an external hydraulic actuator via two oil circuits, and a shuttle valve (3) is provided between the two oil circuits; A relief valve assembly (5), wherein the working oil port of the relief valve assembly (5) is connected to the shuttle valve (3), the oil inlet of the relief valve assembly (5) is connected to the control port of the pressure compensation valve (2) and the oil inlet of the external pipeline, and the oil return port of the relief valve assembly (5) is connected to the oil return port of the external pipeline. The relief valve assembly (5) is used to adjust the pressure difference before and after the proportional reversing valve (1).

2. The multi-stage pressure-compensated proportional reversing valve assembly according to claim 1, characterized in that: A throttle (4) is connected between the overflow valve assembly (5), the control port of the pressure compensation valve (2), and the oil inlet of the external pipeline.

3. The multi-stage pressure-compensated proportional reversing valve assembly according to claim 2, characterized in that: The relief valve assembly (5) comprises two relief valves (52) and an electromagnetic reversing valve (51); the oil inlet of the electromagnetic reversing valve (51) is connected to the control port of the pressure compensation valve (2) and the oil inlet of the external pipeline; the oil outlet of the electromagnetic reversing valve (51) is connected to the oil return port of the external pipeline; the two relief valves (52) are respectively connected between the shuttle valve (3) and the electromagnetic reversing valve (51) through two independent pipelines; and the two relief valves (52) are respectively connected to the two working oil ports of the electromagnetic reversing valve (51).

4. The multi-stage pressure-compensated proportional reversing valve assembly according to claim 3, characterized in that: The two overflow valves (52) are respectively a first overflow valve (521) and a second overflow valve (522), and their setting values are P m1 and P m2 , P m1 ≠P m2 .

5. The multi-stage pressure-compensated proportional reversing valve assembly according to claim 4, characterized in that: The throttle (4) is connected between the control port of the electromagnetic reversing valve (51) and the pressure compensation valve (2) and the oil inlet of the external pipeline.

6. The multi-stage pressure-compensated proportional reversing valve assembly according to claim 5, characterized in that: When the electromagnetic reversing valve (51) is de-energized, the second overflow valve (522) is communicated with the oil return port of the external pipeline, and the oil inlet of the first overflow valve (521) is communicated with the control port of the pressure compensation valve (2) through the throttle (4) on the one hand, and with the oil inlet of the external pipeline through the throttle (4) on the other hand.

7. The multi-stage pressure-compensated proportional reversing valve assembly according to claim 6, characterized in that: If the system set load pressure is PL, the initial spring force of the pressure compensation valve (2) is PK, when the electromagnetic reversing valve (51) is not energized, the initial pressure P2 of the oil inlet of the electromagnetic reversing valve (51) = PL + P m1 The set value of the pressure compensation valve (2) and the oil inlet pressure of the proportional reversing valve (1) are P1=P2+PK=PL+P m1 +PK, pressure difference before and after the proportional reversing valve ΔP=P m1 +PK.

8. The multi-stage pressure-compensated proportional reversing valve assembly according to claim 5, characterized in that: When the electromagnetic reversing valve (51) is energized, the first overflow valve (521) is communicated with the oil return port of the external pipeline, and the oil inlet of the second overflow valve (522) is communicated with the control port of the pressure compensation valve (2) through the throttle (4) on the one hand, and with the oil inlet of the external pipeline through the throttle (4) on the other hand.

9. The multi-stage pressure-compensated proportional reversing valve assembly according to claim 8, characterized in that: If the system set load pressure is PL, the initial spring force of the pressure compensation valve (2) is PK, when the electromagnetic reversing valve (51) is energized, the initial pressure P2 of the oil inlet of the electromagnetic reversing valve (51) is P2 = PL + P m2 The set value of the pressure compensation valve (2) and the oil inlet pressure of the proportional reversing valve (1) are P1=P2+PK=PL+P m2 +PK, pressure difference before and after the proportional reversing valve ΔP=P m2 +PK.

10. The multi-stage pressure-compensated proportional reversing valve assembly according to claim 2, characterized in that: The relief valve assembly (5) includes a proportional relief valve (53), the working oil port of the proportional relief valve (53) is connected to the shuttle valve (3), and the oil inlet of the proportional relief valve (53) is connected to the control port of the pressure compensation valve (2) and the oil inlet of the external pipeline.

Images