Pressure compensation device

Abstract

The utility model relates to a pressure compensation device which comprises a shell (7) and a valve core (1) which is elastically and movably arranged between an oil inlet (8) of the shell (7) and a spring cavity (5) through a spring (4), a feedback oil pickup port (10) which is connected with the spring cavity (5) through an internal feedback pipeline is arranged on the valve core (1), and a first one-way valve (2) is arranged on the feedback pipeline. A feedback pipeline between the first one-way valve (2) and the spring cavity (5) is divided into two independent oil ways, one oil way is provided with the second one-way valve (3), and the other oil way is provided with a damper (6). According to the pressure compensation device, the stability requirement and the response speed requirement of the compound action of the multi-way valve can be effectively met.

Description

Technical Field

[0001] This utility model relates to a pressure compensation device, belonging to the field of crane technology. Background Technology

[0002] Currently, wheeled cranes mainly perform four actions during upper-board operations: telescoping, luffing, hoisting, and slewing. Telescoping, luffing, and main / auxiliary hoisting are all controlled by a multi-way valve on the upper-board unit. This multi-way valve is typically powered by one or two oil pumps. High-pressure hydraulic oil passes through the directional valves of each action to drive the corresponding moving parts. During wheeled crane operation, two or more actions may be combined. Since different actions have different loads, this results in varying pressures in the working oil circuits. If the multi-way valve lacks a compensation function, hydraulic oil will preferentially flow to the working circuit with the lower load pressure, causing the actions with higher loads to remain unresponsive. Therefore, a pressure compensation device needs to be added to the multi-way valve to ensure the feasibility and smoothness of combined actions. A multi-way valve is an integrated valve group composed of multiple directional valves, capable of opening, closing, and reversing multiple actions. The pressure compensation device on the multi-way valve automatically adjusts the oil circuit opening, distributing the flow rate to different actions to ensure the smoothness and response speed of combined actions.

[0003] The feedback oil in existing multi-way valve pressure compensation devices is usually drawn from before the compensation valve core and connected to the inlet. After the main valve stem reverses, the compensation valve core moves upward under the pressure of the hydraulic oil in its lower chamber, connecting the outlet and inlet. (See [reference]). Figure 1The feedback oil circuits of the compensation devices for different actions of the multi-way valve are connected. When the working oil circuit of other actions is a high-load pressure circuit, the pressure of the feedback oil circuit is higher than the pressure of the current action oil circuit. The hydraulic oil in the feedback oil circuit enters the spring chamber, causing the valve core of the compensation valve to move downward. This reduces the opening between the compensation valve core and the working oil circuit, thus reducing the flow rate in the current working oil circuit. Consequently, more flow is distributed to the high-load pressure circuit, achieving a combination of high-load pressure action and low-load pressure action. When the working oil circuit of other actions is a low-load pressure circuit, the compensation valve core moves upward, increasing the opening between the inlet and outlet. Under the pressure of the feedback oil in the spring chamber, the displacement of the compensation valve core on the low-load pressure side is restricted, achieving a combination of system flow distribution to the high-load pressure side during combined action. Because the feedback oil pickup port is located before the compensating valve core, there is a certain pressure difference between it and the working oil circuit. In the existing technology, there is only one passage between the feedback oil port and the spring chamber of the compensating valve. Although there is a detachable damper, the size of the damping directly affects the opening and closing speed of the compensating valve. When the diameter of the damping orifice is large, the compensating valve opens and closes quickly, resulting in poor stability of the current action when another action intervenes. When the diameter of the damping orifice is small, the compensating valve opens and closes slowly, resulting in slow response of the newly intervened action when performing compound actions. Therefore, the existing technical solution cannot simultaneously meet the requirements of stability and response speed of compound actions.

[0004] Chinese patent CN207596344U discloses a multi-way valve with a compensator and a control system with the multi-way valve. A check valve is provided between the pressure pickup port and the feedback port of each valve group. The feedback ports of different compensators on different valve groups are interconnected and cut off in reverse by the check valve. This improves the response speed of heavy load action, but reduces the initial response speed of light load action. When the load difference of the composite action of two or more actions is large, there is an impact or delay in the action.

[0005] Therefore, there is an urgent need for a pressure compensation device that can meet the requirements of both smoothness and response speed of compound actions when the loads of different multi-way valves vary greatly. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a pressure compensation device that can meet the requirements of both stability and response speed of compound actions when the loads of different multi-way valves differ significantly.

[0007] The purpose of this utility model is achieved as follows:

[0008] A pressure compensation device includes a housing, a valve core that is elastically and movably disposed between the oil inlet of the housing and the spring cavity by means of a spring, a feedback oil pickup port that is connected to the spring cavity through an internal feedback pipeline on the valve core, a first check valve that is disposed on the feedback pipeline, and the feedback pipeline between the first check valve and the spring cavity is divided into two independent oil circuits, one of which is provided with a second check valve and the other of which is provided with a damper.

[0009] Furthermore, the feedback oil pickup port is connected to the oil outlet of the housing.

[0010] Furthermore, a screw plug is provided on the housing, and the spring is disposed between the valve core and the screw plug.

[0011] Furthermore, the valve core is provided with a feedback oil port that communicates with the feedback pipeline, and the first one-way valve is located between the feedback oil port and the feedback oil pickup port. The feedback oil port and the spring cavity are connected through the two independent oil circuits.

[0012] Furthermore, the feedback ports of the various pressure compensation devices responsible for different load actions are interconnected.

[0013] Furthermore, the internal feedback pipeline of the valve core is T-shaped, including a horizontal pipeline and a vertical pipeline, and the first check valve is set at the intersection of the horizontal pipeline and the vertical pipeline.

[0014] Furthermore, a protrusion is provided on the horizontal pipeline for mounting the one-way spring of the first one-way valve, so that the valve ball of the first one-way valve can be elastically blocked in one direction in the vertical pipeline.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This invention sets up two passages between the feedback oil port of the pressure compensation device and the spring cavity of the compensation valve core. Each passage is equipped with a check valve or damper, so that the hydraulic oil in the pressure feedback oil circuit enters the spring cavity and the hydraulic oil in the spring cavity returns to the feedback oil circuit through different passages. This allows the pressure compensation device to open smoothly and close quickly, avoiding the problem of unstable operation caused by the opening of the pressure compensation device. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an existing multi-way valve pressure compensation device.

[0018] Figure 2 This is a structural schematic diagram of a pressure compensation device according to the present invention.

[0019] Figure 3 This is a schematic diagram illustrating the working principle of a pressure compensation device according to this utility model.

[0020] in:

[0021] Valve core 1, first check valve 2, second check valve 3, spring 4, spring chamber 5, damping 6, housing 7, oil inlet 8, oil outlet 9, feedback oil pickup port 10, feedback oil port 11, screw plug 12. Detailed Implementation

[0022] See Figures 2-3 This utility model relates to a pressure compensation device, comprising a housing 7 and a valve core 1 elastically movably disposed between the oil inlet 8 and the spring cavity 5 of the housing 7 by a spring 4. A screw plug 12 is provided on the housing 7, and the spring 4 is disposed between the valve core 1 and the screw plug 12 to provide the valve core 1 with the elastic force required for compensation action. A feedback oil pickup port 10 is provided on the valve core 1 and connected to the spring cavity 5 through an internal feedback pipeline. The feedback oil pickup port 10 is connected to the oil outlet 9 of the housing 7, that is, oil is taken from after the compensation valve, which is closer to the working oil circuit pressure, so that the flow distribution of the compound action is more accurate.

[0023] The internal feedback pipeline of the valve core 1 is T-shaped, including a horizontal pipeline and a vertical pipeline. The first one-way valve 2 is set at the intersection of the horizontal and vertical pipelines. A protrusion is provided on the horizontal pipeline for mounting the one-way spring of the first one-way valve 2, so that the valve ball of the first one-way valve 2 elastically blocks the vertical pipeline in one direction. The feedback pipeline between the first one-way valve 2 and the spring cavity 5 is divided into two independent oil circuits. One circuit is equipped with a second one-way valve 3, and the other circuit is equipped with a damper 6. The valve core 1 is provided with a feedback oil port 11 that communicates with the horizontal pipeline of the feedback pipeline. The feedback oil ports 11 of the pressure compensation devices responsible for different load actions are interconnected. The first one-way valve 2 is located between the feedback oil port 11 and the feedback oil pickup port 10. The feedback oil port 11 and the spring cavity 5 are connected through the two independent oil circuits.

[0024] After the directional valve of the multi-way valve reverses, high-pressure hydraulic oil enters the compensation device through the inlet 8. The compensation valve core 1 moves upward under the action of the hydraulic oil. At this time, the hydraulic oil in the spring chamber 5 needs to slowly enter the feedback port 11 through the damper 6, which limits the upward movement speed of the compensation valve core 1, so that the compensation device can operate smoothly during the start-up process and reduce the impact on the current action caused by the start-up of the compensation device. At the same time, the hydraulic oil enters the outlet 9 and the feedback oil pickup port 10, and enters the feedback port 11 through the first check valve 2.

[0025] Combined with appendix Figure 3 The schematic diagram of a multi-way valve is provided to further illustrate the pressure compensation principle during combined load operation: The partial hydraulic schematic diagrams of two actions within the multi-way valve are shown in the appendix. Figure 3In the figure, V1 represents the first directional valve, V2 represents the second directional valve, C1 represents the first compensation device, and C2 represents the second compensation device; P represents the inlet oil circuit, T represents the return oil circuit, and LS represents the feedback oil circuit; as well as working oil circuits A1, A2, A3, and A4, and control oil circuits X1, X2, X3, and X4, etc., wherein both compensation devices adopt the pressure compensation devices in the embodiment;

[0026] When two or more actions are combined, the first directional valve V1 that controls the current action is switched first, and the first compensation device C1 is in the open state. At this time, another action is intervened, the second directional valve V2 is switched, and the second compensation device C2 is opened. Its feedback pressure is transmitted to the feedback port 11 of the first compensation device C1 through the feedback oil circuit LS. When the load pressure of the newly intervened action is high, the pressure of the feedback oil circuit LS is higher than the feedback pressure of the first compensation device C1. The feedback oil enters the first compensation device C1 through its feedback oil port 11, and quickly enters the spring chamber 5 through the second check valve 3. The compensation valve core 1 moves downward under pressure, and the flow rate from the oil inlet 8 to the oil outlet 9 decreases. The flow rate of the current action decreases, thus achieving the effect of distributing more flow to the action with high load pressure. When the load pressure of the newly intervened action is low, the pressure of the feedback oil circuit LS is the feedback pressure of the first compensation device C1. The high-pressure hydraulic oil in the spring chamber 5 of the second compensation device C2 restricts the displacement and upward movement speed of its compensation valve core 1, so that the second compensation device C2 opens smoothly and restricts the flow rate of the newly intervened action, thereby distributing more flow to the action with high load pressure.

[0027] Therefore, by setting two passages between the feedback port 11 of the pressure compensation device and the spring cavity 5 of the compensation valve core 1, and installing a check valve or damper on each passage, the hydraulic oil in the feedback oil circuit of the pressure compensation device enters the spring cavity 5 and the hydraulic oil in the spring cavity 5 returns to the feedback oil circuit through different passages. The passage with the check valve can allow the pressure compensation device to open smoothly and close quickly, achieving the high-speed response requirement. The passage with the damper can avoid the problem of unstable operation caused by the opening of the pressure compensation device. Thus, it can take into account both the stability and response speed requirements of the compound action when the load pressure of the multi-way valve varies greatly.

[0028] Additionally, it should be noted that the above-described specific implementation is merely an optimized solution of this patent, and any modifications or improvements made by those skilled in the art based on the above concept are within the scope of protection of this patent.

Claims

1. A pressure compensation device comprising a housing (7), a valve core (1) elastically movably disposed between an oil inlet (8) of the housing (7) and a spring cavity (5) by a spring (4), a feedback oil pickup port (10) connected to the spring cavity (5) via an internal feedback pipeline on the valve core (1), and a first check valve (2) disposed on the feedback pipeline, characterized in that: The feedback pipeline between the first check valve (2) and the spring chamber (5) is divided into two independent oil circuits, one of which is equipped with a second check valve (3) and the other is equipped with a damper (6).

2. The pressure compensation device according to claim 1, characterized in that: The feedback oil pickup port (10) is connected to the oil outlet (9) of the housing (7).

3. The pressure compensation device according to claim 1, characterized in that: A screw plug (12) is provided on the housing (7), and the spring (4) is provided between the valve core (1) and the screw plug (12).

4. The pressure compensation device according to claim 1, characterized in that: The valve core (1) is provided with a feedback oil port (11) that is connected to the feedback pipeline. The first one-way valve (2) is located between the feedback oil port (11) and the feedback oil pickup port (10). The feedback oil port (11) and the spring cavity (5) are connected through the two independent oil circuits.

5. The pressure compensation device according to claim 4, characterized in that: The feedback ports (11) of the pressure compensation devices responsible for different load actions are interconnected.

6. The pressure compensation device according to claim 1, characterized in that: The internal feedback pipeline of the valve core (1) is T-shaped, including a horizontal pipeline and a vertical pipeline, and the first check valve (2) is set at the intersection of the horizontal pipeline and the vertical pipeline.

7. The pressure compensation device according to claim 6, characterized in that: A protrusion is provided on the horizontal pipeline for mounting the one-way spring of the first one-way valve (2) to elastically block the valve ball of the first one-way valve (2) in one direction on the vertical pipeline.

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