Pressure-adjustable balance valve
By designing a pressure-adjustable balancing valve and controlling the valve core's movement using pressure difference, the hydraulic system achieves adaptive adjustment, solving the problem of traditional balancing valves' inflexible adjustment and improving the safety and production efficiency of coal mining.
Patent Information
- Application Number
- CN202423172230.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-12-23
AI Technical Summary
Traditional balancing valves cannot be flexibly adjusted according to complex and ever-changing working conditions, leading to frequent leakage of gangue between supports during coal mining, which affects safety and production efficiency.
A pressure-adjustable balancing valve was designed. By coordinating the adjustment component and the valve core component, the valve core movement is controlled by the pressure difference, achieving adaptive adjustment between the rodless chamber and the rod chamber, thus ensuring the stability of the hydraulic system.
It enables flexible adjustment according to different load conditions, reduces the leakage of slag between frames, and improves the safety and production efficiency of the hydraulic system.
Smart Images
Figure CN223498303U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of hydraulic control technology, and in particular to a pressure-adjustable balance valve. Background Technology
[0002] In hydraulic systems, balance valves play a crucial role, primarily controlling the movement speed of actuators (such as jacks), preventing loads from falling due to their own weight, and maintaining stable system pressure. With the continuous development of industrial technology, the performance requirements for hydraulic systems are increasingly stringent, especially in fields such as coal mining, where higher standards are being set for the control precision, stability, and safety of hydraulic supports.
[0003] Traditional balancing valves have certain limitations. On the one hand, the inter-support force depends entirely on the inter-support load and cannot be flexibly adjusted according to the complex and ever-changing actual conditions of the working face. During coal mining, the geological conditions of the working face are complex and diverse, with significant differences in rock characteristics and roof pressure in different areas. A fixed inter-support force cannot adapt to these changes, leading to frequent rock leakage between the hydraulic supports in coal mines. This not only poses a serious threat to the lives of underground personnel, but also the falling rock can easily damage equipment, thus affecting production progress and economic benefits. On the other hand, when rock leakage occurs between the hydraulic supports in coal mines, existing technology can only rely on bottom-adjusting jacks to adjust the posture of the entire support to solve the problem. Operators need to precisely operate the bottom-adjusting jacks, gradually adjusting the support posture, and continuously monitor and evaluate the adjustment effect. Any improper operation may cause new safety problems or fail to effectively solve the rock leakage problem. Utility Model Content
[0004] The purpose of this invention is to provide a pressure-adjustable balancing valve to solve the technical problems of functional limitations, poor adaptability, and inability to effectively adjust existing technologies.
[0005] To solve the above problems, the pressure-adjustable balancing valve of this utility model adopts the following technical solution:
[0006] This utility model provides a pressure-adjustable balancing valve, comprising a rodless chamber, a rod chamber, and a return oil chamber, wherein the return oil chamber is connected to the rodless chamber. The valve is characterized by further comprising an adjusting chamber connecting the rodless chamber and the rod chamber, wherein:
[0007] The regulating chamber is equipped with a regulating component, which includes a regulating valve chamber and a valve core assembly that is guided and assembled in the regulating valve chamber. The valve core assembly is respectively topped with a return spring and a balance spring at both ends. The elastic force of the balance spring is greater than that of the return spring. The regulating valve chamber has a first connecting hole that communicates with the liquid inlet end of the rodless chamber, a second connecting hole that communicates with the liquid outlet end of the rodless chamber, and a third connecting hole that communicates with the rod chamber. The valve core assembly has a squeezing surface that is hydraulically pushed by the rodless chamber and can be guided towards the balance spring.
[0008] When the pressure at the inlet end of the rodless chamber is not less than the pressure at the outlet end of the rodless chamber, the balance spring pushes the valve core assembly to move forward and squeezes the reset spring to contract, thereby connecting the first and second connecting holes and blocking the third connecting hole.
[0009] When the pressure at the inlet end of the rodless chamber is less than the pressure at the outlet end of the rodless chamber, the valve core assembly moves in the opposite direction due to the back pressure at the outlet end of the rodless chamber and the push of the return spring, thus squeezing the balance spring to block the first connecting hole and connect the second and third connecting holes.
[0010] Preferably, the regulating valve chamber includes a main valve chamber having a first connecting hole and a second connecting hole thereon, and a balance valve chamber having a third connecting hole thereon. The main valve chamber and the balance valve chamber are connected. The valve core assembly includes a main valve core guided and assembled in the main valve chamber and a balance valve core guided and assembled in the balance valve chamber. The main valve core can control the opening and closing of the first connecting hole by moving along the main valve chamber. The balance valve core can control the opening and closing of the third connecting hole by moving along the balance valve chamber. The return spring and the balance spring are located in the main valve chamber and the balance valve chamber, respectively, and the return spring and the balance spring are respectively mounted on the relatively far ends of the main valve core and the balance valve core. The balance valve core has a pressing surface that can be guided towards the balance spring by hydraulic extrusion from the rodless chamber.
[0011] Preferably, the balance valve chamber includes a balance valve chamber and a pressure regulating seat that is adjustable to the balance valve chamber. The balance valve core is guided and assembled in the balance valve chamber. The two ends of the balance spring abut against the balance valve core and the pressure regulating seat respectively. The user adjusts the initial state of the balance spring by adjusting the relative position of the pressure regulating seat and the balance valve chamber.
[0012] Preferably, an alternating valve assembly is provided in the rodless chamber. The alternating valve assembly includes an alternating valve chamber and an alternating valve core that is guided and assembled in the alternating valve chamber. A return spring is mounted on one end of the alternating valve core. The side wall of the alternating valve chamber has a fourth connecting hole that communicates with the liquid inlet end of the rodless chamber, a fifth connecting hole that communicates with the liquid outlet end of the rodless chamber, and a sixth connecting hole that communicates with the oil return chamber. The alternating valve core has a pressure surface that can be guided towards the return spring by hydraulic extrusion from the liquid inlet end of the rodless chamber.
[0013] When liquid enters the rodless chamber inlet, the alternating valve core moves forward under the hydraulic pressure of the rodless chamber inlet and pushes the return spring to block the sixth connecting hole and connect the fourth and fifth connecting holes.
[0014] When liquid returns from the outlet end of the rodless chamber, the return spring squeezes the alternating valve core to move in the opposite direction, thereby blocking the fourth connecting hole and connecting the fifth and sixth connecting holes.
[0015] The beneficial effects of this utility model are as follows:
[0016] This utility model provides a pressure-adjustable balancing valve, which differs from existing technologies in that it includes a rodless chamber, a rod chamber, a return oil chamber, and an adjusting chamber connecting the rodless and rod chambers. The adjusting chamber is equipped with an adjusting component, which includes a valve core assembly consisting of an adjusting valve chamber and a guide assembly. A return spring and a balance spring are mounted on both ends of the valve core. The side wall of the adjusting valve chamber has holes communicating with the inlet and outlet ends of the rodless chamber and the rod chamber. The valve core has a pressing surface. During operation, when the pressure at the inlet end of the rodless chamber is not less than the pressure at the outlet end, the balance spring pushes the valve core to move forward, connecting the inlet and outlet ends of the rodless chamber and blocking the rod chamber. When the pressure at the inlet end is less than the pressure at the outlet end, the valve core moves in the reverse direction, blocking the inlet end and connecting the outlet end of the rodless chamber with the rod chamber. This valve uses pressure difference to control the valve core's movement, achieving adaptive adjustment between the rodless and rod chambers and ensuring the stability of the hydraulic system. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly described below:
[0018] Figure 1 This is a schematic diagram of the overall structure of a pressure-adjustable balancing valve.
[0019] Figure 2 This is a schematic diagram of the alternating valve assembly.
[0020] Figure 3 Schematic diagram of the main valve chamber structure;
[0021] Figure 4 Application examples of pressure-adjustable balancing valves
[0022] Figure 5 This is the functional symbol for a balancing valve.
[0023] In the diagram: 1. Valve body; 21. Plug; 22. Screw sleeve; 23. Balance valve chamber; 24. Pressure regulating seat; 25. Main valve core; 26. Balance valve core; 27. First liquid hole; 28. Second liquid hole; 29. Third liquid hole; 3. First connecting hole; 4. Second connecting hole; 5. Third connecting hole; 6. Return spring; 7. Balance spring; 8. Spring seat; 9. First baffle; 10. Second baffle; 11. Crimping connector; 12. Alternating valve chamber; 13. Alternating valve core; 14. Return spring; 15. Fourth connecting hole; 16. Fifth connecting hole; 17. Sixth connecting hole; Detailed Implementation
[0024] To make the technical objectives, technical solutions, and beneficial effects of this utility model clearer, the technical solution of this utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.
[0025] This utility model provides a pressure-adjustable balancing valve, as shown in the figure, including a valve body 1. The valve body 1 has a rodless chamber, a rod chamber, a return oil chamber, and an adjustment chamber. The return oil chamber is connected to the rodless chamber, and the adjustment chamber is connected to the rodless chamber and the rod chamber. The valve body 1 has PA port, PB port, A port, B port, and PC port. The two ends of the rodless chamber are connected to PA port (liquid inlet end) and A port (liquid outlet end). The two ends of the rod chamber are connected to B port and PB port. The two ends of the return oil chamber are connected to PC port and the rodless chamber.
[0026] The regulating chamber is equipped with a regulating component, which includes a regulating valve chamber, a valve core assembly with a guide mounted in the regulating valve chamber, a return spring 6, and a balance spring 7. The elastic force of the balance spring 7 is greater than that of the return spring 6.
[0027] The regulating valve chamber includes a main valve chamber with a first connecting hole 3 and a second connecting hole 4, a balance valve chamber 23 with a third connecting hole 5, and a pressure regulating seat 24 that is adjustable to the balance valve chamber 23. The main valve chamber is connected to the balance valve chamber 23. The first connecting hole 3 is connected to the liquid inlet end of the rodless chamber. The second connecting hole 4 is connected to the liquid outlet end of the rodless chamber. The third connecting hole 5 is connected to the rod chamber.
[0028] The valve core assembly includes a main valve core 25 guided and assembled in the main valve chamber, and a balance valve core 26 guided and assembled in the balance valve chamber 23. A return spring 6 and a balance spring 7 are respectively mounted on the opposite far ends of the main valve core 25 and the balance valve core 26. The other end of the balance spring 7 abuts against the pressure regulating seat 24, and the other end of the return spring 6 abuts against the inner wall of the main valve chamber. When the balance valve core 26 is guided and moved away from the main valve core 25 along the balance valve chamber 23, it can squeeze the balance spring 7 to contract. When the main valve core 25 is guided and moved away from the balance valve core 26 along the main valve chamber, it can squeeze the return spring 6 to contract.
[0029] The main valve core 25 has a main liquid chamber, and the main valve core 25 has a first liquid hole 27 and a second liquid hole 28 that communicate with the main liquid chamber on its peripheral wall.
[0030] The main valve chamber includes a plug 21 and a sleeve 22 screwed to one end of the plug 21. Both the plug 21 and the sleeve 22 are fitted onto the outside of the main valve core 25. The main valve core 25 can slide along the axial direction of the sleeve 22 (plug 21). The outer end face of the sleeve 22 has a channel for communication between the main valve core 25 and the outside. The inner wall of the sleeve 22 and the inner wall of the plug 21 are stepped (i.e., the end face of the sleeve 22 protrudes from the inner wall of the plug 21 at the fitting point). A first baffle 9 is provided on the peripheral wall of the main valve core 25, which can abut against the inner end face of the sleeve 22 to limit its continued sliding towards the sleeve 22. A return spring 6 is fitted onto the main valve core 25, and the two ends of the return spring 6 abut against the first baffle 9 and the inner end face of the sleeve 22, respectively. The outer peripheral wall of the first baffle 9 is attached to the inner peripheral wall of the screw plug 21 to seal the gap between them. The outer peripheral wall of the first baffle 9 is attached to the inner peripheral wall of the screw plug 21 to seal the gap between them. The first connecting hole 3 and the second connecting hole 4 are respectively opened on the screw plug 21 and the screw plug 22, and are respectively located on both sides of the axial direction where the outer peripheral wall of the main valve core 25 is attached to the inner peripheral wall of the screw plug 22. During the process of the main valve core 25 moving axially along the main valve cavity after the spring deformation recovers, the first liquid hole 27 can enter the screw plug 22 and attach to the inner peripheral wall of the screw plug 22 to seal the first connecting hole 3. During the process of the main valve core 25 moving axially along the main valve cavity after the spring deformation recovers, the first liquid hole 27 can pass out from the screw plug 22 to communicate with the first connecting hole 3. The second liquid hole 28 is always connected to the second connecting hole 4.
[0031] The balance valve core 26 has a balance fluid chamber, and a third fluid hole 29 communicating with the balance fluid chamber is formed on the peripheral wall of the balance valve core 26. The balance valve core 26 and the main valve core 25 have openings at their respective ends that communicate with their respective main fluid chambers and balance fluid chambers, and the main valve chamber and the balance valve chamber 23 have passages at their respective ends that communicate with their respective balance valve core 26 or main valve core 25.
[0032] The balance valve chamber 23 is also equipped with a spring seat 8 that guides it. The two ends of the balance spring 7 abut against the spring seat 8 and the pressure regulating seat 24, respectively. The balance valve core 26 abuts against the spring seat 8. A conical limiting chamber is formed inside the balance valve chamber 23. A second baffle 10 is provided on the peripheral wall of the balance valve core 26, located in the conical limiting chamber. During the guide movement of the balance valve core 26 along the balance valve chamber 23, the second baffle 10 can abut against any side of the conical limiting chamber to limit the axis of the balance valve core 26. As the valve moves a certain distance, the balance valve core 26 comes into contact with the inner peripheral wall of the balance valve cavity 23 to seal the gap between them. The balance valve core 26 moves along the balance valve cavity 23 in the balance direction to squeeze the balance spring 7 to contract by pushing the spring seat 8. The third liquid hole 29 can enter the area where the balance valve core 26 comes into contact with the inner peripheral wall of the balance valve cavity 23 to seal the third liquid hole 29. That is, during the process of the balance valve core 26 squeezing the balance spring 7 to contract and move, the third liquid hole 29 can be connected or disconnected from the third connecting hole 5.
[0033] An alternating valve assembly is provided in the rodless chamber. The alternating valve assembly includes an alternating valve chamber and an alternating valve core guided and assembled in the alternating valve chamber. The alternating valve chamber has a chamber that runs through both ends. One end of the alternating valve chamber is configured as a fourth connecting hole that connects its inner chamber to the liquid inlet (PA port) of the rodless chamber. The other end of the alternating valve chamber is configured as a sixth connecting hole that connects to the oil return chamber (PC port). A fifth connecting hole is also provided on the side wall of the alternating valve chamber that connects to the liquid outlet (A port) of the rodless chamber. A return spring is installed in the alternating valve chamber and is mounted on the other end of the alternating valve core. When the valve core is not subjected to external force, the return spring pushes the alternating valve core to block the fourth connecting hole. The fifth and sixth connecting holes are connected. When liquid enters through the PA port and pushes the alternating valve core towards the sixth connecting hole, the hydraulic pressure overcomes the spring force of the return spring and pushes the alternating valve core towards the sixth connecting hole. The alternating valve core blocks the sixth connecting hole, and the fourth and fifth connecting holes are connected. A crimping connector 11 is installed on the oil return end of the alternating valve assembly.
[0034] This pressure-adjustable balancing valve involves multiple pressure state changes during operation, which are analyzed in detail below:
[0035] 1. Pressure regulation process when liquid enters through PA port
[0036] Initial fluid supply stage: When the pressure-type balance valve is supplying fluid normally, fluid enters through port 1PA of the valve body. The fluid passes through the regulating component and enters the alternating valve assembly. The alternating valve core moves upward under the pressure of the fluid, overcoming the spring force of the return spring, and blocks the flow channel of port PC. The fluid enters the actuator (such as the rodless chamber of the side protection jack) from port A. Fluid returns normally from port PB to port B. This stage is the normal fluid supply path establishment process. Each component operates according to the normal process to ensure that the actuator can obtain hydraulic oil supply from port PA.
[0037] Pressure rises to set pressure 1 stage: When the load pressure of the actuator is too high, causing the pressure in the flow channel between port PA and port A to rise, the balance valve core 26 in the alternating valve assembly overcomes the spring force of the balance spring 7 and moves to the right. Simultaneously, the main valve core 25 in the alternating valve assembly moves to the right under the action of the return spring 6. When the set pressure is reached, the first liquid hole 27 on the main valve core 25 enters and abuts against the threaded sleeve 22, disconnecting the first liquid hole 27 from the first connecting hole 3. Liquid supply from port PA to port A stops, and the pressure at port A is maintained at the set pressure. The set pressure is adjusted by the threaded connection of the pressure regulating seat 24 to regulate the initial stroke of the balance spring 7. Its function is to cut off the liquid supply through the action of the valve core assembly when the pressure reaches the set value, keeping the actuator working under the set pressure to prevent damage to the system from excessive pressure, and also preparing for possible further pressure adjustment.
[0038] During the pressure increase phase: As the pressure in the flow channel between port PA and port A continues to rise, the balance valve core 26 continues to move to the right against the spring force of the balance spring 7. The main valve core 25 moves to the right simultaneously under the action of the return spring 6. The third liquid hole 29 on the balance valve core 26 connects to the third connecting hole 5, connecting the flow channels of port A, port B, and port PB on the valve body 1 to achieve pressure relief and maintain local pressure stability at port A. This phase is a further adjustment action of the balance valve when the load pressure of the actuator further increases. By connecting port A with other flow channels to achieve pressure relief, the pressure at port A is stabilized within the set pressure range, ensuring the safe and stable operation of the system. At the same time, it can also adaptively adjust according to different load pressure conditions to maintain system pressure balance.
[0039] 2. The return process when liquid enters through the PB port
[0040] When the pressure-type balance valve is supplying fluid normally, fluid enters through port PB of the valve body and flows into port B through the flow channel; fluid returns through port A, passing through the alternating valve assembly. Under the action of the return spring force and hydraulic pressure, the alternating valve core moves towards the fourth connecting hole, closing the flow channel between port A and port PA, and opening the flow channel between port A and port PC, thus realizing the return function from port A to port PC. During this process, port PB acts as the fluid inlet to supply hydraulic oil to the actuator (such as the rod chamber of the side guard jack). At the same time, the return fluid from port A is connected to port PC through the action of the alternating valve assembly, thereby returning the hydraulic oil in the rodless chamber of the actuator to the oil tank, ensuring that the actuator can complete the retraction action normally. All components work together to realize the circulation of hydraulic oil in the system and maintain the normal operation of the system. Specific implementation examples:
[0042] Pressure changes during the extension of the side guard jack
[0043] When the side protection jack extends, liquid enters through port PA of the pressure-type balance valve, passes through the main valve core 25 and balance valve core 26 in the valve core assembly, and enters the alternating valve assembly. The alternating valve core, under hydraulic pressure, overcomes the spring force of the return spring and moves upward, blocking the flow channel at port PC. Liquid then enters the rodless chamber of the side protection jack from port A, and the liquid in the rod chamber of the side protection jack returns normally from port PB to port B. This process provides the power for the side protection jack to extend, enabling it to operate normally.
[0044] When the side support jack extends, the side support plates come into contact with each other, increasing the load. This causes a pressure increase in the flow channel connecting the rodless chamber of the side support jack and the PA port to the A port. The balance valve core 26 in the balance valve assembly moves to the right against the spring force of the balance spring 7. The main valve core 25 in the valve core assembly moves to the right simultaneously under the action of the return spring 6. At the same time, the side support jack continues to extend. When the local system pressure in the rodless chamber rises to the set pressure, the first liquid hole 27 on the main valve core 25 is sealed by the screw plug 21, closing the flow channel between the first liquid hole 27 and the first connecting port. The liquid supply from the PA port to the A port stops, the side support jack stops operating, and the pressure in the rodless chamber is maintained at the set pressure. When the load on the side support jack increases, the balance valve adjusts to stabilize the pressure in the rodless chamber of the side support jack at the set pressure, ensuring that there is a certain supporting force between the side support plates of the working face hydraulic support, solving or reducing the problem of leakage between the hydraulic supports in coal mines. Furthermore, the set pressure can be adjusted according to different working face conditions, realizing flexible adjustment of the support force between the supports.
[0045] When the geological conditions of the longwall mining face change or the hydraulic supports in the coal mine operate, causing the load on the side support jacks to increase again, the local system pressure in the rodless chamber of the valve continues to rise. The balance valve core 26 in the balance valve assembly overcomes the spring force of the balance spring 7 and continues to move to the right. The main valve core 25 in the valve core assembly moves to the right simultaneously under the action of the return spring 6. The third liquid hole 29 on the balance valve core 26 connects with the third connecting hole 5, connecting the flow channels of port A, port B, and port PB on the valve body 1, thereby realizing the pressure relief of the rodless chamber of the side support jacks, maintaining the local system pressure stable within the set range, and ensuring the support force between the two supports of the longwall mining face.
[0046] Pressure changes during the retraction of the side guard jack
[0047] When the side protection jack retracts, liquid enters through port PB of the pressure-type balance valve, flows through the flow channel to port B, and enters the rod chamber of the side protection jack. Liquid returns from the rodless chamber of the side protection jack through port A. Passing through the alternating valve assembly, the alternating valve core moves downwards under the action of the return spring force and hydraulic pressure, closing the flow channel between ports A and PA, and opening the flow channel between ports A and PC. This achieves the return function from the rodless chamber of the side protection jack to port PC, ensuring the side protection jack can smoothly complete the retraction action.
[0048] Finally, it should be noted that the above embodiments are only for illustration and not for limiting the technical solutions of this utility model. Any equivalent substitutions and modifications or partial substitutions that do not depart from the spirit and scope of this utility model should be covered within the scope of protection of the claims of this utility model.
Claims
1. A pressure-adjustable balancing valve, comprising a rodless chamber, a rod chamber, and a return oil chamber, wherein the return oil chamber is connected to the rodless chamber, characterized in that, It also includes an adjustment cavity connecting the rodless cavity and the rod cavity, wherein: The regulating chamber is equipped with a regulating component, which includes a regulating valve chamber and a valve core assembly that is guided and assembled in the regulating valve chamber. The valve core assembly is respectively topped with a return spring and a balance spring at both ends. The elastic force of the balance spring is greater than that of the return spring. The regulating valve chamber has a first connecting hole that communicates with the liquid inlet end of the rodless chamber, a second connecting hole that communicates with the liquid outlet end of the rodless chamber, and a third connecting hole that communicates with the rod chamber. The valve core assembly has a squeezing surface that is hydraulically pushed by the rodless chamber and can be guided towards the balance spring. When the pressure at the inlet end of the rodless chamber is not less than the pressure at the outlet end of the rodless chamber, the balance spring pushes the valve core assembly to move forward and squeezes the reset spring to contract, thereby connecting the first and second connecting holes and blocking the third connecting hole. When the pressure at the inlet end of the rodless chamber is less than the pressure at the outlet end of the rodless chamber, the valve core assembly moves in the opposite direction due to the back pressure at the outlet end of the rodless chamber and the push of the return spring, thus squeezing the balance spring to block the first connecting hole and connect the second and third connecting holes.
2. The pressure-adjustable balancing valve according to claim 1, characterized in that, The regulating valve chamber includes a main valve chamber with a first connecting hole and a second connecting hole thereon, and a balance valve chamber with a third connecting hole thereon. The main valve chamber and the balance valve chamber are connected. The valve core assembly includes a main valve core guided and assembled in the main valve chamber and a balance valve core guided and assembled in the balance valve chamber. The main valve core can control the opening and closing of the first connecting hole by moving along the main valve chamber. The balance valve core can control the opening and closing of the third connecting hole by moving along the balance valve chamber. The return spring and the balance spring are located in the main valve chamber and the balance valve chamber, respectively, and the return spring and the balance spring are respectively mounted on the opposite far ends of the main valve core and the balance valve core. The balance valve core has a pressing surface that can be guided towards the balance spring by hydraulic extrusion from the rodless chamber.
3. The pressure-adjustable balancing valve according to claim 2, characterized in that, The balancing valve chamber includes the balancing valve chamber and a pressure regulating seat that is adjustable to the balancing valve chamber. The balancing valve core is guided and assembled in the balancing valve chamber. The two ends of the balancing spring abut against the balancing valve core and the pressure regulating seat respectively. The user adjusts the initial state of the balancing spring by adjusting the relative position of the pressure regulating seat and the balancing valve chamber.
4. The pressure-adjustable balancing valve according to claim 1, characterized in that, An alternating valve assembly is provided in the rodless chamber. The alternating valve assembly includes an alternating valve chamber and an alternating valve core that is guided and assembled in the alternating valve chamber. A return spring is mounted on one end of the alternating valve core. The side wall of the alternating valve chamber has a fourth connecting hole that communicates with the liquid inlet end of the rodless chamber, a fifth connecting hole that communicates with the liquid outlet end of the rodless chamber, and a sixth connecting hole that communicates with the oil return chamber. The alternating valve core has a pressure surface that can be guided towards the return spring by hydraulic extrusion from the liquid inlet end of the rodless chamber. When liquid enters the rodless chamber inlet, the alternating valve core moves forward under the hydraulic pressure of the rodless chamber inlet and pushes the return spring to block the sixth connecting hole and connect the fourth and fifth connecting holes. When liquid returns from the outlet end of the rodless chamber, the return spring squeezes the alternating valve core to move in the opposite direction, thereby blocking the fourth connecting hole and connecting the fifth and sixth connecting holes.