Pressure maintaining loop system

Abstract

The pressure maintaining loop system comprises an oil inlet pipeline, an oil return pipeline, a reversing unit, a first valve body, a second valve body, a third valve body and an oil cylinder, a pressure oil port of the reversing unit is connected with the oil inlet pipeline, an oil return port of the reversing unit is connected with the oil return pipeline, one working oil port of the reversing unit is connected with the first valve body, and the other working oil port of the reversing unit is connected with the second valve body. The first valve body is connected with a rodless cavity of the oil cylinder and an oil return pipeline, the other working oil port of the reversing unit is connected with a rod cavity of the oil cylinder, and the second valve body and the third valve body are arranged between the first valve body and the oil return pipeline in parallel. Checking pieces used for detecting leakage of the valve bodies are connected between the first valve body and the reversing unit, between the second valve body and the oil return pipeline and between the third valve body and the oil return pipeline, and when the pressure maintaining loop system does not maintain pressure, a user can judge whether the first valve body, the second valve body and the third valve body leak or not only through the checking pieces. And troubleshooting results are doubled with half effort.

Description

Technical Field

[0001] This application relates to the field of hydraulic devices, and more specifically to a pressure holding circuit system. Background Technology

[0002] The pressure holding circuit in a hydraulic system is an important component of hydraulic technology. Its main function is to maintain stable system pressure when the hydraulic cylinder is stationary or when there is slight displacement due to workpiece deformation. The core function of the pressure holding circuit is to ensure that the hydraulic system maintains stable pressure under different operating conditions. Therefore, pressure holding circuits are commonly used in devices that require precise control of torque, such as hydraulic clamping devices. The hydraulic system needs to maintain a set pressure during operation to ensure clamping force, clamping reliability, and smooth operation.

[0003] In hydraulic systems, pressure holding circuits often contain multiple valves in parallel, such as pressure holding valves, safety relief valves, and pressure relief valves. If any of these valves leak, the pressure holding circuit will be unable to maintain the set pressure. It is necessary to maintain a single variable and replace each valve one by one to find out which valve is leaking and causing the pressure holding circuit to fail to maintain pressure. This troubleshooting process is complex and time-consuming. Summary of the Invention

[0004] One objective of this application is to provide a pressure holding circuit system that is simple and convenient for troubleshooting leaks, thereby solving the problem of complex leak troubleshooting in existing pressure holding circuits.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: a pressure holding circuit system, including an oil inlet pipeline, a return oil pipeline, a reversing unit, a first valve body, a second valve body, a third valve body, and a hydraulic cylinder. The pressure port of the reversing unit is connected to the oil inlet pipeline, and the return oil port of the reversing unit is connected to the return oil pipeline. One working port of the reversing unit is connected to the first valve body. The first valve body is connected to the rodless chamber of the hydraulic cylinder and the return oil pipeline. The other working port of the reversing unit is connected to the rod chamber of the hydraulic cylinder. The second valve body and the third valve body are arranged in parallel between the first valve body and the return oil pipeline. Inspection pieces for detecting valve body leakage are connected between the first valve body and the reversing unit, between the second valve body and the return oil pipeline, and between the third valve body and the return oil pipeline.

[0006] As a preferred embodiment, the inspection component has an internally connected connection channel and an inspection channel. The connection channel has two connection ports, which are adapted to be connected to a pipeline so that the connection channel is connected to a loop system. The inspection channel has an inspection port, on which a sealing bolt is detachably provided. The sealing bolt is adapted to open and close the inspection port.

[0007] As another preferred embodiment, the two connection ports are disposed on the front end face of the inspection piece, and the inspection port is disposed on the top end face of the inspection piece.

[0008] Further preferably, the connection channel is U-shaped.

[0009] Furthermore, the reversing unit is implemented as a three-position four-way reversing valve. The pressure port P of the three-position four-way reversing valve is connected to the oil inlet pipeline, the return port T of the three-position four-way reversing valve is connected to the return pipeline, the working port A of the three-position four-way reversing valve is connected to the first valve body, and the working port B of the three-position four-way reversing valve is connected to the rod chamber of the oil cylinder.

[0010] Furthermore, the first valve body is implemented as a one-way valve, which is adapted to allow the oil in the pipeline to flow only from the working port A to the rodless chamber of the cylinder.

[0011] Furthermore, the second valve body is implemented as a two-position two-way solenoid valve, which can be energized or de-energized to conduct or disconnect. When the two-position two-way solenoid valve is energized, the oil can flow from the rodless chamber of the oil cylinder to the return oil pipeline through the two-position two-way solenoid valve.

[0012] Furthermore, the third valve body is implemented as an overflow valve, which is adapted to open when the pressure in the rodless chamber of the oil cylinder reaches a preset value, so that the oil flows to the return oil line.

[0013] Furthermore, an accumulator is provided on the pipeline between the first valve body and the rodless chamber of the oil cylinder. The accumulator is adapted to store oil when the circuit pressure exceeds the pre-charge pressure and to release oil when the circuit pressure is lower than the pre-charge pressure.

[0014] Furthermore, a pressure sensor is also provided on the pipeline between the first valve body and the rodless chamber of the oil cylinder. The pressure sensor is connected in parallel with the accumulator and is adapted to acquire pressure information in the rodless chamber of the oil cylinder.

[0015] Compared with the prior art, the beneficial effects of this application are as follows:

[0016] In the pressure holding circuit system provided in this application, an inspection element is installed on the pipeline on the side of each valve body away from the oil cylinder. The inspection element is equipped with a connection channel and an inspection channel. The connection channel is suitable for connecting to each valve body to access the circuit system, while the inspection channel is suitable for checking the condition of the connection channel. During inspection, the user only needs to remove the sealing bolt on the inspection channel and observe whether oil flows out of the connection channel to determine whether each valve body has a leakage problem. The detection of leakage points is very convenient, and the troubleshooting is twice as efficient. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the pressure holding loop system of this application.

[0018] Figure 2 This is a formal drawing of the inspection component in the pressure holding loop system of this application.

[0019] Figure 3 This is a cross-sectional view of the inspection component AA in the pressure holding circuit system of this application.

[0020] In the diagram: 100, oil inlet line; 200, oil return line; 300, three-position four-way directional valve; 400, one-way guide valve; 500, two-position two-way solenoid valve; 600, relief valve; 700, hydraulic cylinder; 800, pressure sensor; 900, accumulator; 1000, inspection piece; 1010, connection channel; 1020, inspection channel. Detailed Implementation

[0021] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0022] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this application.

[0023] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0024] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0025] A pressure holding circuit system includes an oil inlet line 100, an oil return line 200, a reversing unit, a first valve body, a second valve body, a third valve body, and a hydraulic cylinder 700.

[0026] like Figure 1-3 As shown, the reversing unit is implemented as a three-position four-way reversing valve 300. The three-position four-way reversing valve 300 has a pressure port P, a return port T, a working port A, and a working port B. When the three-position four-way reversing valve 300 is in the left position, the pressure port P is connected to the working port A, and the return port T is connected to the working port B. When the three-position four-way reversing valve 300 is in the middle position, the pressure port P is closed, and the return port T is connected to both the working ports A and B. When the three-position four-way reversing valve 300 is in the right position, the pressure port P is connected to the working port B, and the return port T is connected to the working port A.

[0027] The pressure port P is connected to the inlet pipe 100, the return port T is connected to the return pipe 200, the working port A is connected to the first valve body, the first valve body is connected to the rodless chamber of the cylinder 700, the working port B is connected to the rod chamber of the cylinder 700 and the return pipe 200, the second valve body and the third valve body are connected in parallel between the first valve body and the return pipe 200, and an accumulator 900 and a pressure sensor 800 are also installed on the pipe between the first valve body and the rodless chamber of the cylinder 700. The accumulator 900 stores oil when the circuit pressure exceeds the pre-charge pressure and releases oil when the circuit pressure is lower than the pre-charge pressure. The pressure sensor 800 is suitable for obtaining the pressure information of the rodless chamber-accumulator 900 branch of the cylinder 700 and displaying the pressure of the rodless chamber-accumulator 900 branch of the cylinder 700 in real time.

[0028] Preferably, the first valve body is implemented as a one-way valve 400, the second valve body is implemented as a two-position two-way solenoid valve 500, and the third valve body is implemented as a relief valve 600. The one-way valve 400 only allows oil to flow in one direction, so that the oil can only flow from the working port A to the rodless chamber of the cylinder 700; the two-position two-way solenoid valve 500 is in a normally closed state, that is, when the two-position two-way solenoid valve 500 is not energized, the valve of the two-position two-way solenoid valve 500 is closed, and the oil cannot pass through the two-position two-way solenoid valve 500; when the two-position two-way solenoid valve 500 is energized, the valve of the two-position two-way solenoid valve 500 is open, and the oil can pass through the two-position two-way solenoid valve 500; the relief valve 600 is also in a normally closed state, and only when the pressure in the pipeline exceeds a preset value will the valve of the relief valve 600 open, and the oil can pass through the relief valve 600.

[0029] Specifically, when the three-position four-way directional valve 300 is in the left position, the oil flows from the pressure port P to the working port A. After passing through the one-way guide valve 400, part of the oil enters the rodless chamber of the cylinder 700, and part of the oil enters the accumulator 900. The oil in the rod chamber of the cylinder 700 flows from the working port B to the return port T, and the rod of the cylinder 700 moves outward. When the three-position four-way directional valve 300 is in the neutral position, the one-way guide valve 400, the two-position two-way solenoid valve 500, and the relief valve 600 are all in the open state, and the oil in the rodless chamber of the cylinder 700 cannot flow back to the return line. 200, thus ensuring the pressure in the rodless chamber of the hydraulic cylinder 700. At the same time, when the pressure in the rodless chamber of the hydraulic cylinder 700 decreases, the accumulator 900 can release oil into the rodless chamber of the hydraulic cylinder 700 to ensure that the pressure in the rodless chamber of the hydraulic cylinder 700 does not decrease. When the three-position four-way directional valve 300 is in the right position, the oil flows from the pressure port P to the working oil port B and enters the rod chamber of the hydraulic cylinder 700. The two-position two-way solenoid valve 500 is energized and enters the closed state. The oil in the rodless chamber of the hydraulic cylinder 700 flows back to the return oil line through the two-position two-way solenoid valve 500, and the rod of the hydraulic cylinder 700 moves inward.

[0030] Therefore, if any one of the valve bodies of the one-way valve 400, the two-position two-way solenoid valve 500, and the relief valve 600 leaks, the pressure in the rodless chamber of the cylinder 700 cannot be maintained. It is necessary to replace each valve body one by one to find out which valve body is leaking and causing the pressure loss. The troubleshooting is complicated and time-consuming. This application provides a pressure maintaining circuit system based on the above-mentioned problems. An inspection element 1000 is installed on the pipeline at the end of each valve body away from the oil cylinder 700. The inspection element 1000 has a connection channel 1010 for connecting to the circuit system and an inspection channel 1020 for inspecting the connection channel 1010. The connection channel 1010 and the inspection channel 1020 are interconnected. The connection channel 1010 has two connection ports, which are respectively connected to the valve body and the return oil pipeline 200. The connection channel 1010 is U-shaped, and both connection ports are located on the front end face of the inspection element 1000 for easy connection to the pipeline. The inspection channel 1020 is connected to the bottom of the U-shape of the connection channel 1010. The inspection channel 1020 has an inspection port located on the top surface of the inspection element 1000. A sealing bolt (not shown in the figure) is detachably installed at the inspection port, and the sealing bolt is suitable for opening and closing the inspection port.

[0031] The inability of the circuit system to maintain pressure is mostly due to leaks in the valve bodies. When a valve body leaks, some oil flows through the valve body to the return line 200. Therefore, by knowing which valve body has oil flowing to the return line 200, it is possible to determine which valve body is leaking. Specifically, when the circuit system cannot maintain pressure, the user can remove the sealing bolts at the inspection ports of each inspection component 1000 and observe whether there is oil flow in the connection channel 1010 through the inspection port. If there is oil flow in the connection channel 1010, it can be determined that the valve body corresponding to that inspection component 1000 is leaking, thus quickly completing the troubleshooting.

[0032] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A pressure holding loop system, characterized in that, The system includes an oil inlet line, an oil return line, a reversing unit, a first valve body, a second valve body, a third valve body, and a hydraulic cylinder. The pressure port of the reversing unit is connected to the oil inlet line, and the oil return port of the reversing unit is connected to the oil return line. One working port of the reversing unit is connected to the first valve body. The first valve body is connected to the rodless chamber of the hydraulic cylinder and the oil return line. The other working port of the reversing unit is connected to the rod chamber of the hydraulic cylinder. The second valve body and the third valve body are arranged in parallel between the first valve body and the oil return line. Inspection pieces for detecting valve body leakage are connected between the first valve body and the reversing unit, between the second valve body and the oil return line, and between the third valve body and the oil return line.

2. The pressure holding loop system as described in claim 1, characterized in that, The inspection component has an internally connected connection channel and an inspection channel. The connection channel has two connection ports, which are adapted to be connected to a pipeline so that the connection channel is connected to a loop system. The inspection channel has an inspection port, on which a sealing bolt is detachably provided. The sealing bolt is adapted to open and close the inspection port.

3. The pressure holding loop system as described in claim 2, characterized in that, The two connection ports are located on the front end face of the inspection piece, and the inspection port is located on the top end face of the inspection piece.

4. The pressure holding loop system as described in claim 3, characterized in that, The connection channel is U-shaped.

5. The pressure holding loop system as described in claim 3, characterized in that, The reversing unit is implemented as a three-position four-way reversing valve. The pressure port P of the three-position four-way reversing valve is connected to the oil inlet pipeline, the return port T of the three-position four-way reversing valve is connected to the return oil pipeline, the working port A of the three-position four-way reversing valve is connected to the first valve body, and the working port B of the three-position four-way reversing valve is connected to the rod chamber of the oil cylinder.

6. The pressure holding loop system as described in claim 5, characterized in that, The first valve body is implemented as a one-way valve, which is adapted to allow the oil in the pipeline to flow only from the working port A to the rodless chamber of the cylinder.

7. The pressure holding loop system as described in claim 6, characterized in that, The second valve body is implemented as a two-position two-way solenoid valve. The two-position two-way solenoid valve can be energized or de-energized to conduct or disconnect. When the two-position two-way solenoid valve is energized, the oil can flow from the rodless chamber of the oil cylinder to the return oil pipeline through the two-position two-way solenoid valve.

8. The pressure holding loop system as described in claim 7, characterized in that, The third valve body is implemented as an overflow valve, which is adapted to open when the pressure in the rodless chamber of the oil cylinder reaches a preset value, so that the oil flows to the return oil line.

9. The pressure holding loop system as described in any one of claims 1-8, characterized in that, An accumulator is provided on the pipeline between the first valve body and the rodless chamber of the oil cylinder. The accumulator is adapted to store oil when the circuit pressure exceeds the pre-charge pressure and to release oil when the circuit pressure is lower than the pre-charge pressure.

10. The pressure holding loop system as described in claim 9, characterized in that, A pressure sensor is also installed on the pipeline between the first valve body and the rodless chamber of the oil cylinder. The pressure sensor is connected in parallel with the accumulator and is adapted to acquire the pressure information in the rodless chamber of the oil cylinder.

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