A boom holding valve

Abstract

The application discloses a boom holding valve and relates to the valve field, which comprises a valve body, a flow channel is formed in the valve body, a fluid pipe is connected to one end of a hydraulic cylinder close to a telescopic rod, and the fluid pipe is used for supplying fluid; a one-way valve is arranged in the flow channel, the one-way valve comprises a valve seat and a valve core, the valve core can slide on the valve body, an inner cavity is formed in the valve body, and a movable piston push rod is arranged in the inner cavity; a branch pipe is connected to the fluid pipe and communicates with the inner cavity; the valve core in the one-way valve in the valve body is movably arranged, the piston push rod is driven to move by hydraulic pressure, the valve core is further driven to move, the opening and closing of the one-way valve are realized, the telescopic rod of the hydraulic cylinder cannot be retracted under the dead weight of the excavator boom when the fluid input pipe at the inlet of the flow channel bursts, and thus, a safety hazard can be avoided; meanwhile, the valve core can move under the action of the piston push rod, the telescopic rod of the hydraulic cylinder can normally retract and extend, and the working requirement is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of valves, in particular to a boom holding valve. BACKGROUND

[0002] In some current mechanical equipment, such as cranes, excavators, etc., a hydraulic cylinder is generally provided to drive the movement of a large arm. The existing hydraulic cylinder driving mode generally includes a single-acting cylinder and a double-acting cylinder. The working principle of the single-acting cylinder is that fluid only acts on one side of the piston, and the piston is driven to move by controlling the inflow or outflow of fluid, thereby driving the telescopic rod of the hydraulic cylinder to extend or retract. The working principle of the double-acting cylinder is that fluid acts on both sides of the piston, and the telescopic rod of the hydraulic cylinder is extended by controlling the inflow of fluid on one side of the piston and the outflow of fluid on the other side of the piston, and vice versa, the telescopic rod of the hydraulic cylinder is retracted. In the working process of the excavator and other mechanical equipment, the hydraulic cylinder overcomes the weight of the large arm to lift the large arm of the excavator. Once the fluid input pipeline of the hydraulic cylinder driving the telescopic rod to extend bursts, the hydraulic cylinder is depressurized, and the telescopic rod of the hydraulic cylinder quickly retracts due to the weight of the large arm, which causes the large arm to quickly drop, which easily causes safety hazards. SUMMARY

[0003] In order to improve the problem that the burst of the fluid input pipeline easily causes the large arm to quickly drop, the present application provides a boom holding valve.

[0004] The boom holding valve provided by the present application adopts the following technical scheme:

[0005] A boom holding valve, comprising a valve body, the valve body is used to be installed on a hydraulic cylinder, a flow channel is formed in the valve body, an inlet of the flow channel is used for fluid to enter, an outlet of the flow channel is used to communicate with one end of the hydraulic cylinder away from a telescopic rod, one end of the hydraulic cylinder close to the telescopic rod is communicated with a fluid pipe, and the fluid pipe is used for fluid to enter; a one-way valve is arranged in the flow channel, the one-way valve comprises a valve seat and a valve core, the valve seat is arranged in the flow channel, and the valve core can slide on the valve body; the valve core slides to control the opening and closing of the one-way valve; the one-way valve is closed to limit the fluid in the one end of the hydraulic cylinder away from the telescopic rod to be discharged; an inner cavity is formed in the valve body, a movable piston push rod is arranged in the inner cavity, the piston push rod moves to push the valve core to move and open the one-way valve; a spring one for resetting the valve core is arranged on the valve body; a branch pipe is communicated with the fluid pipe, and the branch pipe communicates the inner cavity with one side of the piston push rod away from the valve core.

[0006] When the hydraulic cylinder telescopic rod needs to extend, fluid enters the flow channel through the flow channel inlet and enters the closed end of the hydraulic cylinder through the one-way valve in the flow channel, and under the action of hydraulic pressure, the hydraulic cylinder telescopic rod extends, and when the hydraulic cylinder telescopic rod needs to be retracted, fluid enters the hydraulic cylinder front end through the fluid pipe at the same time, and fluid enters the inner cavity through the branch pipe, driving the piston push rod to move, thereby driving the valve core to move, and the movement of the valve core opens the one-way valve, and the fluid in the closed end of the hydraulic cylinder is discharged through the flow channel and the opened one-way valve and the flow channel opening, so that the hydraulic cylinder telescopic rod is retracted; when the fluid input pipe at the flow channel inlet bursts, due to the action of the one-way valve, the fluid in the closed end of the hydraulic cylinder cannot pass through the one-way valve, so that the closed end of the hydraulic cylinder cannot be depressurized, and when the hydraulic cylinder supports the excavator boom, if the fluid input pipe at the flow channel inlet bursts, the hydraulic cylinder telescopic rod will not retract under the weight of the excavator boom, thereby avoiding potential safety hazards; at the same time, under the action of the piston push rod, the valve core can move, ensuring that the hydraulic cylinder telescopic rod can normally retract and extend, meeting the work requirements.

[0007] Optionally, the valve body is provided with a driving assembly for driving the piston push rod to move to open the one-way valve.

[0008] By adopting the above technical scheme, when the fluid input pipe bursts, due to the presence of the one-way valve, the fluid in the closed end of the hydraulic cylinder cannot be discharged, which will cause the hydraulic cylinder telescopic rod to be unable to retract, and further cause the excavator boom to be unable to descend, and when the excavator boom needs to be lowered, fluid flows through the branch pipe into the inner cavity, driving or pushing the push rod to move, further driving the valve core to move, opening the one-way valve, so that the fluid in the closed end of the hydraulic cylinder can be discharged, and the excavator boom can be lowered, but during this process, it is difficult to control the descending speed of the hydraulic cylinder telescopic rod, and the excavator boom descending too fast can also cause potential safety hazards, therefore, by driving the piston push rod to move through the driving assembly, driving the valve core to move, and opening the one-way valve, the opening time of the one-way valve and the size of the one-way valve passage opening can be controlled, so that the retracting speed of the hydraulic cylinder telescopic rod can be controlled, avoiding potential safety hazards.

[0009] Optionally, the driving assembly includes a screw rod, the screw rod is threadedly connected with the valve body, and the screw rod rotates to drive the piston push rod to move.

[0010] By adopting the above technical scheme, when the piston push rod is driven to move, the screw rod is rotated, and since the screw rod is threadedly connected with the valve body, the screw rod will displace while rotating, thereby driving the piston push rod to move, and the driving assembly has a simple structure and is easy to operate, and at the same time, the movement amplitude of the screw rod can be improved by improving the screw thread precision of the screw rod, and the movement amplitude of the screw rod determines the movement amplitude of the valve core, thereby the size of the one-way valve passage opening can be controlled to control the retracting speed of the hydraulic cylinder telescopic rod.

[0011] Optionally, the valve body has an installation cavity that communicates with the flow channel. A fixing seat is inserted into the installation cavity and is threadedly connected to the inner wall of the installation cavity. The valve core is slidably inserted into the fixing seat and can be detached from the valve body through the installation cavity.

[0012] By adopting the above technical solution, the setting of the fixed seat facilitates the guiding movement of the valve core. At the same time, the setting of the fixed seat ensures the sealing of the internal flow channel of the valve body. Furthermore, since the fixed seat is threadedly connected to the inner wall of the mounting cavity, the fixed seat and the valve core can be removed, which facilitates the disassembly and assembly of the valve core and the fixed seat.

[0013] Optionally, the fixed seat has a sealing cavity, the valve core has a channel communicating with the sealing cavity, the piston push rod has a guide groove, the guide groove is used to communicate with the channel, and the guide groove is connected to the side of the inner cavity near the valve core, and the side of the inner cavity near the valve core has a pressure relief port.

[0014] By adopting the above technical solution, the sealing cavity can be filled with a medium (such as air and sealing fluid) to further improve the sealing performance of the device. After the sealing cavity is filled with a medium, if the valve core needs to move, the medium needs to flow. At this time, due to the setting of the channel and the guide groove, when the valve core moves to open the check valve, the medium in the sealing cavity enters the guide groove through the flow channel and flows into the inner cavity through the guide groove. The medium in the inner cavity can be discharged through the pressure relief port. At the same time, when filling the medium, the medium can also be input into the sealing cavity through the pressure relief port to ensure the sealing performance of the device.

[0015] Optionally, one side of the inner cavity extends through the valve body so that the piston rod can move away from the inner cavity, and a plug is threadedly connected to the side of the inner cavity extending through the valve body, and a movable seat for pushing the valve core is threadedly connected to the rolling fixed seat.

[0016] By adopting the above technical solution, the piston rod may be damaged after long-term use. When the piston rod needs to be replaced, the plug is removed, and then the moving seat is rotated. The moving seat moves and pushes the valve core to move. The movement of the valve core can push the piston rod to move, thereby allowing the piston rod to be moved out of the inner cavity for replacement.

[0017] Optionally, the movable seat has an operating groove for inserting a tool to drive the movable seat to rotate.

[0018] By adopting the above technical solution, the operation slot is designed to facilitate the rotation of the movable seat, thereby enabling the movable seat to move.

[0019] Optionally, a branch groove is formed in the valve body, the branch groove is communicated with the branch pipe outlet and the inner cavity, and a one-way throttling valve is arranged in the branch groove, and the one-way throttling valve is used to make the flow rate of fluid flowing from the branch groove into the inner cavity greater than the flow rate of fluid flowing from the inner cavity into the branch groove.

[0020] By adopting the technical scheme, the one-way throttling valve is arranged, the flow rate of fluid flowing into the inner cavity is greater, so that the piston push rod can be quickly pushed to make the one-way valve open, thereby quickly retracting the hydraulic cylinder during work to ensure work efficiency, and when fluid flows out of the inner cavity, the valve core is reset under the action of the spring one, at this time, the flow rate of fluid flowing out of the inner cavity is smaller, so that the reset speed of the valve core can be slowed down to prevent the piston push rod from being damaged due to a large collision with the plug because of too fast reset of the valve core.

[0021] In summary, the present application has the following beneficial technical effects:

[0022] 1. The present application realizes the opening and closing of the one-way valve by the movable arrangement of the valve core in the one-way valve in the valve body and the movement of the piston push rod driven by the hydraulic pressure, thereby moving the valve core, ensuring that the hydraulic cylinder telescopic rod will not retract under the weight of the excavator boom when the fluid inlet pipe at the flow passage inlet bursts, thereby avoiding safety hazards; at the same time, the valve core can move under the action of the piston push rod, ensuring that the hydraulic cylinder telescopic rod can normally retract and extend to meet the work requirements.

[0023] 2. The present application is movable by the movable arrangement of the moving seat, moves the moving seat, moves the valve core, and then pushes out the piston push rod, thereby facilitating the disassembly work of the piston push rod. DETAILED DESCRIPTION

[0024] Figure 1 is a whole structure schematic view of a boom holding valve applied to a hydraulic cylinder disclosed by the present application;

[0025] Figure 2 is a whole structure schematic view of a boom holding valve disclosed by the present application;

[0026] Figure 3 is Figure 2 a sectional view of Figure 1 ;

[0027] Figure 4 is Figure 3 an enlarged schematic view of the A area in

[0028] Figure 5 is Figure 2 a sectional view of Figure 1 ;

[0029] Figure 6 is Figure 5 an enlarged schematic view of the B area in

[0030] BRIEF DESCRIPTION OF DRAWINGS

[0031] 1. valve body; 2. hydraulic cylinder; 3. flow channel; 4. fluid pipe; 5. mounting cavity; 6. one-way valve; 7. valve seat; 8. valve core; 9. fixed cylinder; 10. moving cylinder; 11. spring two; 12. fixed seat; 13. notch; 14. sealing cavity; 15. spring one; 16. blocking block; 17. inner cavity; 18. piston push rod; 19. branch pipe; 20. branch groove; 21. passage; 22. flow guide groove; 23. pressure relief port; 24. screw; 25. plug; 26. moving seat; 27. operation groove; 28. one-way throttle valve. DETAILED DESCRIPTION

[0032] The following will be described in detail in combination with the accompanying drawings Figures 1-6 The application is further described in detail.

[0033] The application discloses a boom holding valve.

[0034] Referring to Figure 1 and Figure 2 A boom holding valve, comprising a valve body 1, the valve body 1 is used for being mounted on a hydraulic cylinder 2, in the embodiment, the valve body 1 is fixed on the outer wall of the fixed end of the hydraulic cylinder 2 by a screw, a flow channel 3 is arranged in the valve body 1, the inlet of the flow channel 3 is used for allowing fluid to enter, the outlet of the flow channel 3 is used for being communicated with the end of the hydraulic cylinder 2 away from the telescopic rod (the closed end of the hydraulic cylinder 2), the end of the hydraulic cylinder 2 close to the telescopic rod is communicated with a fluid pipe 4 (the front end of the hydraulic cylinder 2), the fluid pipe 4 is used for allowing fluid to enter;

[0035] Referring to Figure 2 and Figure 3 When the telescopic rod of the hydraulic cylinder 2 needs to be extended out of the hydraulic cylinder 2, the external fluid enters the flow channel 3 through the inlet of the flow channel 3, and then enters the closed end of the hydraulic cylinder 2 through the outlet of the flow channel 3, the hydraulic pressure in the closed end of the hydraulic cylinder 2 increases, so that the telescopic rod of the hydraulic cylinder 2 is extended, when the telescopic rod of the hydraulic cylinder 2 needs to be retracted, the external fluid enters the front end of the hydraulic cylinder 2 through the fluid pipe 4, and the liquid in the closed end of the hydraulic cylinder 2 is discharged through the flow channel 3, so that the telescopic rod of the hydraulic cylinder 2 is retracted.

[0036] Referring to Figure 3 and Figure 4In the above working process, in order to make the hydraulic cylinder 2 telescopic rod not quickly descend due to the weight of the load (such as the excavator boom) when the fluid input pipe connected with the inlet of the flow channel 3 bursts, a mounting cavity 5 is arranged in the valve body 1, the mounting cavity 5 is communicated with the flow channel 3, that is, the fluid can enter the mounting cavity 5 through the inlet of the flow channel 3 and then enter the flow channel 3 through the mounting cavity 5; the mounting cavity 5 is provided with a one-way valve 6, the one-way valve 6 comprises a valve seat 7 and a valve core 8, the valve seat 7 comprises a fixed cylinder 9 and a movable cylinder 10, the fixed cylinder 9 is fixed in the mounting cavity 5, the movable cylinder 10 can move in the mounting cavity 5, and the fixed cylinder 9 and the movable cylinder 10 are fixedly connected with a spring 11;

[0037] A fixed seat 12 is arranged in the mounting cavity 5, a plurality of notches 13 are formed in the outer wall of the fixed seat 12 and communicated with the mounting cavity 5, a sealing cavity 14 is formed in the fixed seat 12, one end of the valve core 8 is slidably inserted into the sealing cavity 14, the other end of the valve core 8 extends out of the sealing cavity 14 and simultaneously passes through the fixed cylinder 9 and the movable cylinder 10, a spring 15 is fixedly connected with the valve core 8 along the length direction of the valve core 8 in the sealing cavity 14, the spring 11 is used for resetting the valve core 8, the valve core 8 is integrally formed with a blocking block 16 on the outer wall, when the spring 11 and the spring 15 are not deformed, the blocking block 16 abuts against the movable cylinder 10, at this time, the one-way valve 6 is in a closed state, and the fluid cannot pass through the one-way valve 6.

[0038] Referring to Figure 3 and Figure 4 When the fluid is injected into the inlet of the flow channel 3, the fluid passes through the mounting cavity 5 and the notches 13 and presses the movable cylinder 10, under the action of the hydraulic pressure, the movable cylinder 10 moves, the spring 11 is deformed, the movable cylinder 10 is separated from the blocking block 16, then the fluid can flow into the closed end of the hydraulic cylinder 2 through the one-way valve 6, after the fluid is injected from the inlet of the flow channel 3, the spring 15 restores the deformation, the movable cylinder 10 abuts against the blocking block 16, then the fluid in the closed end of the hydraulic cylinder 2 cannot be discharged from the inlet of the flow channel 3 through the one-way valve 6, at this time, the telescopic rod of the hydraulic cylinder 2 cannot quickly descend due to the weight of the load (such as the excavator boom).

[0039] In normal working, the telescopic rod of the hydraulic cylinder 2 needs to be constantly retracted and extended, and due to the arrangement of the one-way valve 6, the work cannot be normally performed, in order to make the hydraulic cylinder 2 normally retract and extend, an inner cavity 17 is formed in the valve body 1, a movable piston push rod 18 is arranged in the inner cavity 17, one end of the valve core 8 away from the fixed seat 12 extends into the inner cavity 17 and is in sealed arrangement with the inner cavity 17, and the other end of the valve core 8 close to the inner cavity 17 is also integrally formed with a blocking block 16, the hydraulic areas of the two blocking blocks 16 are the same, the piston push rod 18 moves to push the valve core 8 to move and make the one-way valve 6 open (the blocking block 16 is separated from the movable cylinder 10); a branch pipe 19 is communicated with the fluid pipe 4 and the inner cavity 17 on the side away from the valve core 8 of the piston push rod 18.

[0040] With reference to Figure 3 And Figure 4 Because of the existence of the one-way valve 6, the fluid in the closed end of the hydraulic cylinder 2 cannot be discharged, so the telescopic rod of the hydraulic cylinder 2 cannot be retracted. When the telescopic rod of the hydraulic cylinder 2 needs to be retracted, the fluid enters the front end of the hydraulic cylinder 2 from the fluid pipe 4 through the setting of the piston push rod 18, so that the telescopic rod of the hydraulic cylinder 2 has a tendency to retract. The fluid enters the inner cavity 17 from the branch pipe 19, drives the piston push rod 18 to move, and then pushes the valve core 8, so that the blocking block 16 is separated from the moving cylinder 10. The one-way valve 6 is opened, so that the fluid in the closed end of the hydraulic cylinder 2 can be discharged from the fluid inlet through the one-way valve 6, so that the telescopic rod of the hydraulic cylinder 2 is retracted.

[0041] In order to facilitate the disassembly of the fixed seat 12, so as to remove the valve core 8, the installation cavity 5 penetrates one side of the valve body 1, and the fixed seat 12 and the inner wall of the installation cavity 5 are threadedly connected. By rotating the fixed seat 12, the fixed seat 12 can be removed, and then the valve core 8 can be removed.

[0042] With reference to Figure 3 And Figure 4 In order to ensure the sealing of the device, a medium (such as air and liquid) can be injected into the sealing cavity 14. The valve core 8 is provided with a channel 21 communicating with the sealing cavity 14. The piston push rod 18 is provided with a flow guide groove 22. The flow guide groove 22 is used for communication with the channel 21, and the flow guide groove 22 is in communication with the side of the inner cavity 17 close to the valve core 8. The side of the inner cavity 17 close to the valve core 8 is provided with a pressure relief port 23.

[0043] When the piston push rod 18 moves, it drives the valve core 8 to move, so that the medium in the sealing cavity 14 enters the inner cavity 17 through the channel 21 and the flow guide groove 22, and can be discharged through the pressure relief port 23 (normally, the pressure relief port 23 is connected to a sealed container).

[0044] In addition, when the fluid input pipe connected to the inlet of the communication flow channel 3 bursts, the telescopic rod of the hydraulic cylinder 2 can be slowly retracted. The valve body 1 is provided with a driving assembly for driving the piston push rod 18 to move to open the one-way valve 6.

[0045] With reference to Figure 3 And Figure 4 The driving assembly includes a screw rod 24. One side of the inner cavity 17 penetrates the valve body 1 so that the piston push rod 18 can move away from the inner cavity 17. The side of the inner cavity 17 penetrating the valve body 1 is threadedly connected with a plug 25. The screw rod 24 extends into the inner cavity 17 through the plug 25, and the screw rod 24 and the plug 25 are threadedly connected. When the screw rod 24 rotates, the screw rod 24 and the plug 25 produce relative displacement, so that the screw rod 24 can push the piston push rod 18 to move.

[0046] In another embodiment, the driving assembly can also be an electric push rod.

[0047] In this embodiment, the piston rod 18 is prone to damage during long-term use. To facilitate the replacement of the piston rod 18, a movable seat 26 is threaded onto the fixed seat 12. The movable seat 26 can rotate to move closer to the valve core 8. A spring 15 is disposed between the movable seat 26 and the valve core 8. When it is necessary to remove the damaged piston rod 18, the plug 25 is removed. Then, when the movable seat 26 is rotated, the movable seat 26 moves closer to the valve core 8 and pushes the valve core 8 to move with the help of the spring 15. The movement of the valve core 8 drives the piston rod 18 to move until the piston rod 18 is disengaged from the inner cavity 17.

[0048] To facilitate the rotation of the movable base 26, an operating groove 27 is provided on the movable base 26 for inserting tools to drive the movable base 26 to rotate.

[0049] Reference Figure 5 and Figure 6 The valve body 1 has a branch groove 20 inside, which connects the outlet of the branch pipe 19 and the inner cavity 17. The branch groove 20 is equipped with a one-way throttle valve 28, which is used to make the flow rate of the fluid entering the inner cavity 17 from the branch groove 20 greater than the flow rate of the fluid entering the branch groove 20 from the inner cavity 17.

[0050] The implementation principle of a boom holding valve in this embodiment is as follows: During normal operation of the hydraulic cylinder 2, when the extension rod of the hydraulic cylinder 2 needs to extend, external fluid enters the mounting cavity 5 through the inlet of the flow channel 3, and squeezes the moving cylinder 10 through the mounting cavity 5 and the notch 13, causing the one-way valve 6 to open. The fluid enters the closed end of the hydraulic cylinder 2 through the one-way valve 6 and the flow channel 3, causing the extension rod of the hydraulic cylinder 2 to extend. When the extension rod of the hydraulic cylinder 2 needs to retract, external fluid enters the front end of the hydraulic cylinder 2 from the fluid pipe 4, causing the extension rod of the hydraulic cylinder 2 to tend to retract. On the other hand, fluid enters the inner cavity 17 from the branch pipe 19, driving the piston push rod 18 to move, thereby pushing the valve core 8 to seal. When block 16 detaches from moving cylinder 10, check valve 6 opens, allowing fluid at the closed end of hydraulic cylinder 2 to be discharged from the fluid inlet through check valve 6, thus retracting the telescopic rod of hydraulic cylinder 2. When the fluid input pipe at the inlet of flow channel 3 bursts, the fluid at the closed end of hydraulic cylinder 2 cannot be discharged due to the presence of check valve 6. Therefore, the telescopic rod of hydraulic cylinder 2 will not descend rapidly due to the weight of the load (such as the excavator boom), avoiding safety hazards. When it is necessary to retract the telescopic rod of hydraulic cylinder 2, screw 24 is rotated, driving piston push rod 18 to move, which in turn drives valve core 8 to move, opening check valve 6. This allows fluid at the closed end of hydraulic cylinder 2 to be discharged, and the telescopic rod of hydraulic cylinder 2 to retract slowly, ensuring safety performance.

[0051] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A boom holding valve, comprising a valve body (1) for mounting on a hydraulic cylinder (2), characterized in that: The valve body (1) has a flow channel (3) with an inlet for fluid to enter and an outlet for connecting the end of the hydraulic cylinder (2) away from the telescopic rod. The end of the hydraulic cylinder (2) near the telescopic rod is connected to a fluid pipe (4) for fluid to enter. A one-way valve (6) is provided within the flow channel (3). The one-way valve (6) includes a valve seat (7) and a valve core (8). The valve seat (7) is located within the flow channel (3), and the valve core (8) can be mounted on the valve body (1). The valve core (8) slides to control the opening and closing of the check valve (6). The check valve (6) closes to restrict the discharge of fluid from the end of the hydraulic cylinder (2) away from the telescopic rod. An inner cavity (17) is provided in the valve body (1). A movable piston rod (18) is provided in the inner cavity (17). The piston rod (18) moves to push the valve core (8) to move and open the check valve (6). A spring (15) is provided on the valve body (1) for resetting the valve core (8). The fluid pipe (4) is connected to... A branch pipe (19) is connected to the inner cavity (17) on the side of the piston rod (18) away from the valve core (8); an installation cavity (5) is provided in the valve body (1), the installation cavity (5) is connected to the flow channel (3), a fixing seat (12) is inserted in the installation cavity (5), and the fixing seat (12) is threadedly connected to the inner wall of the installation cavity (5), the valve core (8) is slidably inserted into the fixing seat (12), and the valve core (8) can be disengaged from the valve body (1) through the installation cavity (5); A sealing cavity (14) is provided inside the fixed seat (12). The sealing cavity (14) is filled with a medium to further improve the sealing performance. A channel (21) communicating with the sealing cavity (14) is provided inside the valve core (8). A guide groove (22) is provided on the piston push rod (18). The guide groove (22) is used to communicate with the channel (21). The guide groove (22) is connected to the side of the inner cavity (17) near the valve core (8). A pressure relief port (23) is provided on the side of the inner cavity (17) near the valve core (8).

2. The boom holding valve according to claim 1, characterized in that: The valve body (1) is provided with a drive assembly for driving the piston rod (18) to move so that the one-way valve (6) opens.

3. A boom holding valve according to claim 2, characterized in that: The drive assembly includes a screw (24) threadedly connected to the valve body (1), and the screw (24) rotates to push the piston rod (18) to move.

4. A boom holding valve according to claim 1, characterized in that: The inner cavity (17) extends through the valve body (1) on one side so that the piston rod (18) can move away from the inner cavity (17). A plug (25) is threadedly connected to the inner cavity (17) extending through the valve body (1). A movable seat (26) for pushing the valve core (8) is threadedly connected to the fixed seat (12).

5. A boom holding valve according to claim 4, characterized in that: The movable base (26) has an operating groove (27) for inserting tools to drive the movable base (26) to rotate.

6. A boom holding valve according to claim 1, characterized in that: The valve body (1) has a branch groove (20) inside, the branch groove (20) connects the outlet of the branch pipe (19) and the inner cavity (17), and a one-way throttle valve (28) is provided in the branch groove (20). The one-way throttle valve (28) is used to make the flow rate of fluid entering the inner cavity (17) from the branch groove (20) greater than the flow rate of fluid entering the branch groove (20) from the inner cavity (17).

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