Pressure compensation valve and hydraulic control system

Abstract

The utility model belongs to the technical field of hydraulic valves, and discloses a pressure compensation valve and a hydraulic control system. The pressure compensation valve comprises a valve sleeve, a valve seat and a valve element. An oil inlet hole, an oil return hole and a feedback oil hole are formed in the valve sleeve, a connecting corner is arranged on the inner wall of the valve sleeve, and the connecting corner is located between the oil return hole and the feedback oil hole; the valve seat is connected with the valve sleeve; the valve element is slidably arranged in the valve sleeve in the axial direction so as to block or open the oil return hole, the valve element is provided with a first valve element section and a second valve element section, the first valve element section and the valve seat form a first cavity, an oil passing gap is formed between the first valve element section and the valve seat, and the first cavity and the feedback oil hole are communicated through the oil passing gap; a sealing part is arranged between the first valve element section and the second valve element section and can abut against the connecting corner so as to block a gap, between the oil return hole and the feedback oil hole, between the valve sleeve and the valve element. The pressure compensation valve is good in sealing effect, and hydraulic oil leakage is effectively avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic valves, in particular to a pressure compensation valve and a hydraulic control system. Background Art

[0002] Pressure-compensating valves are widely used in construction machinery. For example, after lifting cargo to a preset position, forklifts must maintain pressure to prevent the forklift from dropping due to gravity. However, hydraulic oil leakage is a common problem with pressure-compensating valves in the industry, resulting in poor hydraulic control.

[0003] Therefore, it is necessary to provide a pressure compensation valve and a hydraulic control system to solve the above technical problems. Utility Model Content

[0004] The purpose of the utility model is to provide a pressure compensating valve to solve the problems of poor sealing effect between the valve core and the valve sleeve, and difficult and high cost in machining the sealing structure.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A pressure compensating valve, comprising:

[0007] A valve sleeve, wherein the valve sleeve has an oil inlet hole, an oil return hole, and a feedback oil hole, and an inner wall of the valve sleeve is provided with a connecting corner, wherein the connecting corner is located between the oil return hole and the feedback oil hole;

[0008] a valve seat connected to the valve sleeve;

[0009] a valve core slidably disposed in the valve sleeve along the axial direction to block or open the oil return hole; the valve core having a first valve core section and a second valve core section; the first valve core section and the valve seat forming a first chamber; an oil flow gap being defined between the first valve core section and the valve seat, the oil flow gap communicating the first chamber with the feedback oil hole; a sealing portion being disposed between the first valve core section and the second valve core section, the sealing portion being capable of abutting against the connecting angle to block the gap between the valve sleeve and the valve core between the oil return hole and the feedback oil hole;

[0010] Preferably, the valve sleeve comprises a first body and a second body connected to each other in the axial direction, the inner diameter of the first body is larger than the inner diameter of the second body, and a connection angle is formed at the connection between the first body and the second body.

[0011] Preferably, the diameter of the first valve core segment is larger than the diameter of the second valve core segment, the first valve core segment and the second valve core segment are connected via a tapered segment, the outer diameter of the end of the tapered segment connected to the first valve core segment is larger than the outer diameter of the end of the tapered segment connected to the second valve core segment, the circumferential surface of the tapered segment forms the sealing portion, the first valve core segment is located in the first main body, and the second valve core segment is slidingly guided in cooperation with the second main body.

[0012] Preferably, along the axial direction of the valve core, the oil gap is an annular cavity provided between the valve core and the valve seat, and a single-side size of the oil gap is 0.2-0.5 mm.

[0013] Preferably, an oil flow groove is included, which is located on the valve seat and / or the valve core. When the oil flow groove is located on the valve seat, the groove wall of the oil flow groove is recessed relative to the inner wall of the valve seat toward the side away from the valve core to form the oil flow gap; when the oil flow groove is located on the valve core, the wall of the oil flow groove is recessed relative to the surface of the valve core toward the side away from the valve seat to form the oil flow gap.

[0014] Preferably, the first valve core section is provided with a one-way throttling channel connected to the first chamber and the feedback oil hole, and a sealing member is provided in the one-way throttling channel, and the sealing member is used to control the one-way flow of the hydraulic oil from the first chamber to the one-way throttling channel.

[0015] Preferably, the one-way throttling channel includes a throttling hole, a accommodating chamber and an oil passage connected in sequence, the other end of the throttling hole is connected to the first chamber, the other end of the oil passage is connected to the feedback oil hole, and the sealing member is arranged in the accommodating chamber, and the sealing member is used to disconnect or connect the throttling hole and the accommodating chamber.

[0016] Preferably, the oil passage includes a first oil hole, a second oil hole and an annular groove that are connected in sequence; the first oil hole is arranged along the axial direction of the valve core, the second oil hole is arranged along the radial direction of the valve core, and the annular groove is arranged along the circumferential direction of the valve core, and the other end of the first oil hole is connected to the accommodating cavity, and the annular groove is connected to both the feedback oil hole and the oil gap.

[0017] Preferably, the pressure compensating valve further comprises a plug, which is arranged in the first valve core section of the valve core, and the throttle hole and the accommodating cavity are both opened in the plug.

[0018] Another object of the present invention is to provide a hydraulic control system so that the load will not shake when maintained at a certain height, thereby improving the hydraulic control effect.

[0019] To achieve this purpose, the present invention adopts the following technical solutions:

[0020] A hydraulic control system comprising:

[0021] A lifting cylinder and a lifting module for controlling the lifting cylinder to perform lifting actions, wherein the lifting module includes an oil inlet and an oil outlet, and a solenoid valve is provided between the oil inlet and the oil inlet end of the lifting cylinder;

[0022] A proportional flow valve and a pressure compensation valve as claimed in claim are sequentially arranged between the oil inlet end and the oil outlet of the lifting cylinder, the oil inlet hole of the pressure compensation valve is connected to the proportional flow valve, the oil return hole is connected to the oil outlet, and the feedback oil hole is connected to the oil inlet end of the lifting cylinder.

[0023] Beneficial effects of the utility model:

[0024] The utility model discloses a pressure compensating valve. The pressure compensating valve includes a valve sleeve, a valve seat and a valve core. The valve sleeve is provided with an oil inlet hole, an oil return hole and a feedback oil hole. The inner wall of the valve sleeve is provided with a connecting corner, and the connecting corner is located between the oil return hole and the feedback oil hole; the valve seat is connected to the valve sleeve; the valve core is slidably arranged in the valve sleeve along the axial direction to block or open the oil return hole, and the valve core has a first valve core section and a second valve core section, the first valve core section and the valve seat form a first chamber, and there is an oil gap between the first valve core section and the valve seat, and the oil gap connects the first chamber and the feedback oil hole; a sealing portion is provided between the first valve core section and the second valve core section, and the sealing portion can abut against the connecting corner to block the gap between the valve sleeve and the valve core between the oil return hole and the feedback oil hole.

[0025] In this pressure compensating valve, when hydraulic oil enters from the feedback oil hole, it pushes the valve core to move from left to right. When the valve core moves to the point where the sealing part abuts the connecting corner, the sealing part and the connecting corner can form a conical seal, thereby effectively sealing the gap between the valve core and the valve sleeve between the return oil hole and the feedback oil hole, thereby effectively avoiding hydraulic oil leakage, and thus producing a good sealing effect. In addition, the processing difficulty and cost are low, and it is easy to produce and use.

[0026] The utility model also discloses a hydraulic control system, including a lifting cylinder and a lifting module that controls the lifting cylinder to perform lifting actions, the lifting module including an oil inlet and an oil outlet, and an electromagnetic valve is arranged between the oil inlet and the oil inlet end of the lifting cylinder; a proportional flow valve and a pressure compensation valve as described in the claim are sequentially arranged between the oil inlet end of the lifting cylinder and the oil outlet.

[0027] In this hydraulic control system, the pressure compensation valve has a sealing portion, which can strictly form a cone seal with the connecting corner, thereby avoiding leakage of hydraulic oil, and further making the hydraulic system have good stability when maintaining the load, thereby improving the control effect of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a cross-sectional view of the sealing state of the pressure compensation valve provided by the utility model;

[0029] Figure 2 This is a cross-sectional view of the pressure compensation valve provided by the present invention in a working state;

[0030] Figure 3 This is a schematic diagram of the hydraulic control system provided by the utility model for lifting cargo;

[0031] Figure 4 It is a schematic diagram of the hydraulic control system provided by the present invention for maintaining load.

[0032] In the picture:

[0033] 10. Valve sleeve; 11. Oil inlet hole; 12. Oil return hole; 13. Feedback oil hole; 14. Connecting corner; 15. First body; 16. Second body;

[0034] 20. Valve seat;

[0035] 30. Valve core; 31. First valve core section; 32. Second valve core section; 33. Sealing portion; 34. Accommodating chamber;

[0036] 41. First chamber; 42. Oil gap; 43. Second chamber;

[0037] 51, throttle hole; 52, accommodating chamber; 53, oil passage; 531, first oil passage hole; 532, second oil passage hole; 533, annular groove;

[0038] 60. Sealing parts;

[0039] 70. Plug;

[0040] 80. Elastic structure; 81. Elastic member; 82. Mounting member;

[0041] 100. Lifting cylinder;

[0042] 200, solenoid valve;

[0043] 300, proportional flow valve;

[0044] 400. Filter. DETAILED DESCRIPTION

[0045] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0046] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0047] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0048] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0049] When lifting cargo on a forklift, a proportional valve is typically connected in series with a pressure compensator to compensate for the load. This ensures that the pressure differential between the front and rear ends remains constant despite the weight of the load. However, when the load is maintained at a predetermined height, the gap between the valve core and the valve sleeve can cause hydraulic oil to leak. Reducing the gap between the valve core and the valve sleeve to ensure a tight seal increases manufacturing complexity and significantly increases costs.

[0050] To solve the above problems, Figure 1-Figure 2As shown, this embodiment provides a pressure compensating valve, which is arranged at the rear end of the proportional valve and includes a valve sleeve 10, a valve seat 20, a valve core 30 and an elastic structure 80; wherein the valve sleeve 10 has an oil inlet hole 11, an oil return hole 12, and a feedback oil hole 13, and the inner wall of the valve sleeve 10 is provided with a connecting corner 14, and the connecting corner 14 is located between the oil return hole 12 and the feedback oil hole 13; the valve seat 20 is connected to the valve sleeve 10; the valve core 30 is axially slidable in the valve sleeve 10 to block or open the oil return hole 12, and the valve core 30 has There are a first valve core section 31 and a second valve core section 32. The first valve core section 31 and the valve seat 20 form a first chamber 41. There is an oil gap 42 between the first valve core section 31 and the valve seat 20. The oil gap 42 connects the first chamber 41 and the feedback oil hole 13; a sealing portion 33 is provided between the first valve core section 31 and the second valve core section 32. The sealing portion 33 can abut against the connecting corner 14 to seal the gap between the valve sleeve 10 and the valve core 30 between the return oil hole 12 and the feedback oil hole 13; an elastic structure 80 is provided between the valve sleeve 10 and the second valve core section 32.

[0051] The valve core 30 of this pressure compensation valve is provided with a sealing portion 33. When hydraulic oil enters through the feedback oil hole 13 and pushes the valve core 30 to move from left to right, the sealing portion 33 will abut against the connecting corner 14, thereby preventing the hydraulic oil entering from the feedback oil hole 13 from flowing out through the return oil hole 12, producing a good sealing effect, so that when the load is maintained, there will be no problem of hydraulic oil leakage.

[0052] Taking a forklift as an example, when the forklift's forks are raised or lowered, hydraulic oil typically flows through a one-way valve, a solenoid valve, or a proportional valve to the lifting cylinder, pushing the cylinder upward to lift the cargo. While the cargo is being held, the weight of the cargo acts on the cylinder, generating hydraulic pressure within the cylinder's oil chamber. The hydraulic oil within the chamber is then blocked by the one-way valve, proportional valve, and pressure-compensating valve, thereby ensuring that the cargo remains stable in its raised position. When the cargo needs to be lowered, the solenoid valve is energized, returning the hydraulic oil to the tank to complete the lowering process. The proportional valve controls the current flow to control the lowering speed, while the pressure-compensating valve maintains a substantially constant pressure differential across the proportional valve opening, ensuring that the lowering speed is unaffected by the load. However, pressure-compensating valves typically employ a sliding valve structure, inevitably leading to hydraulic oil leakage from the oil return port 12. In this embodiment, however, the sealing portion 33 abuts the connecting corner 14, ensuring a good seal. This also eliminates the need to reduce the clearance between the valve core 30 and the valve sleeve 10 to address the sealing issue, thereby reducing the overall manufacturing complexity.

[0053] In addition, if Figure 1-Figure 2As shown, the valve sleeve 10 includes a first body 15 and a second body 16 connected to each other along the axial direction. The inner diameter of the first body 15 is larger than the inner diameter of the second body 16. The connection between the first body 15 and the second body 16 forms a connecting corner 14. That is, the connecting corner 14 is a stepped structure formed by the connection between the first body 15 and the second body 16. This structure can simplify the internal structure of the valve sleeve 10. No additional separate components are required within the valve sleeve 10. The first body 15 and the second body 16 of different diameters can be integrally formed to form the corresponding connecting corner 14, thereby reducing overall manufacturing and use costs.

[0054] In addition, if Figure 1-Figure 2 As shown, the diameter of the first valve core segment 31 is larger than that of the second valve core segment 32. The first valve core segment 31 and the second valve core segment 32 are connected by a tapered segment. The outer diameter of the tapered segment at the end connected to the first valve core segment 31 is larger than the outer diameter of the tapered segment at the end connected to the second valve core segment 32. The circumferential surface of the tapered segment forms a sealing portion 33. The valve core 30 is coaxially arranged with the valve sleeve 10. The first valve core segment 31 is located (slidably disposed) within the first body 15, and the second valve core segment 32 is slidingly guided in cooperation with the second body 16.

[0055] By providing a tapered section connecting the first valve core section 31 and the second valve core section 32, the overall structure is simplified and a smooth sealing portion 33 is formed, thereby enhancing the sealing effect with the connecting corner 14. It should be noted that in this embodiment, the sealing portion 33 is a sealing bevel that abuts the connecting corner 14 and forms a tapered seal. By aligning the second valve core section 32 with the second body 16 in a sliding and guiding manner, the second valve core section 32 can only slide axially along the valve sleeve 10, preventing slippage. This reduces collision or wear between the valve core 30 and the valve sleeve 10, extending the service life of the pressure compensating valve and ensuring optimal performance. It should be noted that the diameter of the second valve core section 32 of the valve core 30 can be slightly smaller than the inner diameter of the second body 16. In other words, the difference between the inner diameter of the valve sleeve 10 and the diameter of the second valve core section 32 of the valve core 30 should be within a tolerance range of 0.01-0.02 mm.

[0056] like Figure 1-Figure 2 As shown, along the axial direction of the valve core 30, an annular oil gap 42 is provided between the valve core 30 and the valve seat 20. The single-side dimension of the oil gap 42 is 0.2-0.5 mm. In other words, the diameter of the first valve core segment 31 is 0.4-1 mm smaller than the inner diameter of the first body 15 (0.2-0.5 mm per side), naturally forming the oil gap 42 between the two. This simplifies the overall structure and ensures that hydraulic oil can smoothly flow into the first chamber 41 through the oil gap 42 or out through the oil gap 42.

[0057] In addition, in other embodiments, the pressure compensating valve further includes an oil flow groove, which is located on the valve seat 20 and / or the valve core 30. When the oil flow groove is located on the valve seat 20, the inner wall of the valve seat 20 of the oil flow groove is recessed toward the side away from the valve core 30 to form an oil flow gap 42. When the oil flow groove is located on the valve core 30, the wall of the oil flow groove is recessed relative to the surface of the valve core 30 toward the side away from the valve seat 20 to form an oil flow gap 42. The oil flow gap 42 formed by this structure can be a groove extending axially along the valve core 30, or an annular gap. Regardless of the structure, the hydraulic oil can be guaranteed to flow within the oil flow gap 42. According to actual needs, it is possible to select a structure in which the oil flow groove is only provided in the valve seat 30, a structure in which the oil flow groove is only provided in the valve core 30, or a structure in which the oil flow groove is provided in both the valve seat 20 and the valve core 30. This is not limited in this embodiment.

[0058] In addition, if Figure 1-Figure 2 As shown, the first valve core section 31 is provided with a one-way throttling passage connecting the first chamber 41 and the feedback oil hole 13. A sealing member 60 is installed in the one-way throttling passage to control the unidirectional flow of hydraulic oil from the first chamber 41 to the one-way throttling passage. This structure can adjust the opening of the oil return hole 12 according to changes in system pressure, thereby maintaining a constant pressure difference between the front and rear ends of the proportional valve, ensuring smooth operation even under load changes.

[0059] In this embodiment, if Figure 1-Figure 2As shown, the diameter of the first valve core segment 31 is larger than that of the second valve core segment 32. The outer periphery of the first valve core segment 31 and the inner wall of the first body 15 of the valve sleeve 10 form a second chamber 43. The second chamber 43 is connected to the oil flow gap 42 via an annular groove 533 (the second chamber 43 is located to the right of the oil flow gap 42). The valve seat 20 is disposed at the left end of the valve sleeve 10, the oil inlet 11 is disposed at the right end of the valve sleeve 10, and the oil return hole 12 and feedback oil hole 13 are both circumferentially defined within the valve sleeve 10, with the feedback oil hole 13 located to the left of the oil return hole 12. Axial movement of the valve core 30 can change the area of ​​the oil return hole 12 blocked, thereby varying the opening of the oil return hole 12. After passing through the feedback oil hole 13, the hydraulic oil first enters the second chamber 43, then passes through the oil gap 42 into the first chamber 41 and acts on the left end of the valve core 30. Assuming the pressure at the front end of the proportional valve is F1 and the pressure at the rear end is F2, the hydraulic oil can flow from the feedback oil hole 13 into the pressure compensation valve and then through the oil gap 42 into the first chamber 41. Since the feedback oil hole 13 of the pressure compensation valve is connected to the front end of the flowmeter, the hydraulic oil in the first chamber 41 now exerts a pressure of F1 on the first valve core segment 31. As the hydraulic oil flows from the oil inlet hole 11 into the valve sleeve 10, the hydraulic oil in the valve sleeve 10 now exerts a pressure of F2 on the second valve core segment 32 of the valve core 30. The remaining hydraulic oil can flow out through the oil return hole 12. Since the elastic structure is disposed between the valve sleeve 10 and the second valve core segment 32, the elastic force generated by the elastic structure is assumed to be F3. It can be understood that when the pressure compensation valve is in a balanced state, F1 = F2 + F3.

[0060] When the load at the front end of the fork increases, the fork's descending speed will also tend to increase. At this time, F1 increases, which increases the flow of hydraulic oil entering the first chamber 41 from the feedback oil hole 13, thereby causing the valve core 30 to move to the right to reduce the opening of the oil return hole 12, and further reduces the amount of hydraulic oil passing through the oil return hole 12, thereby reducing the descending speed of the fork, that is, ensuring that the fork can still descend at a stable rate.

[0061] When the load on the fork's front end decreases, the fork's descent rate also tends to decrease. At this time, F1 decreases, reducing the flow of hydraulic oil from the feedback oil hole 13 into the first chamber 41. This in turn causes the valve core 30 to move leftward, widening the opening of the oil return hole 12. This, in turn, increases the amount of hydraulic oil flowing through the oil return hole 12, thereby increasing the fork's descent rate and ensuring that the fork can still descend at a stable rate. At this time, some of the hydraulic oil in the first chamber 41 flows out through the oil gap 42, while some flows into the one-way throttle channel, breaking through the sealing member 60 and flowing out of the one-way throttle channel.

[0062] When the load increases, the hydraulic oil flowing into the first chamber 41 from the feedback oil hole 13 is slowed down by passing through the oil gap 42 and slowing down the flow rate of the hydraulic oil into the first chamber 41, thereby slowing down the movement speed of the valve core 30 to the right, and further slowing down the flow change at the return oil hole 12.

[0063] Specifically, if Figure 1-Figure 2 As shown, the one-way throttling channel includes a throttling hole 51, a receiving chamber 52, and an oil passage 53, which are connected in sequence. The other end of the throttling hole 51 communicates with the first chamber 41, and the other end of the oil passage 53 communicates with the feedback oil hole 13. A blocking member 60 is disposed within the receiving chamber 52. The blocking member 60 is used to disconnect or connect the throttling hole 51 and the receiving chamber 52. When the hydraulic oil in the first chamber 41 flows out of the one-way throttling channel, the hydraulic oil first enters the throttling hole 51, which in turn pushes the blocking member 60 away from the connection between the throttling hole 51 and the receiving chamber 52, allowing the hydraulic oil to pass through the receiving chamber 52 into the oil passage 53 and finally be discharged from the feedback oil hole 13 through the oil passage 53. The provision of the throttling hole 51 can limit the flow rate of the hydraulic oil, thereby achieving an effective throttling effect. The provision of the blocking member 60 ensures that the hydraulic oil can only flow in one direction and cannot enter the throttling hole 51 through the oil passage 53.

[0064] It should be noted that in this embodiment, the blocking member 60 is a steel ball. Steel balls have a simple structure, are easy to manufacture, and offer high hardness, good wear resistance, and corrosion resistance. Using a steel ball to block the one-way throttling channel not only facilitates installation but also provides excellent one-way flow performance.

[0065] In addition, if Figure 1-Figure 2 As shown, the oil passage 53 includes a first oil hole 531, a second oil hole 532, and an annular groove 533, which are connected in sequence. The first oil hole 531 is arranged along the axial direction of the valve core 30, the second oil hole 532 is arranged along the radial direction of the valve core 30, and the annular groove 533 is arranged along the circumference of the valve core 30. The other end of the first oil hole 531 is connected to the accommodating chamber 52, and the annular groove 533 is connected to the feedback oil hole 13 and the oil gap 42. This arrangement enables the first oil hole 531, which is opened in the axial direction, the second oil hole 532, which is opened in the radial direction, and the annular groove 533, which is arranged along the outer circumference, to cooperate with each other. This not only simplifies the overall structure, but also allows the hydraulic oil to flow smoothly in the oil passage 53 without excessive pressure loss and flow resistance, ensuring good performance.

[0066] In addition, if Figure 1-Figure 2As shown, the pressure-compensating valve further includes a plug 70, which is disposed within the first valve core section 31 of the valve core 30. The throttle hole 51 and the accommodating chamber 52 are both disposed within the plug 70. As an independent component, the plug 70 can be precision-machined independently to ensure the dimensional accuracy of the throttle hole 51 and the accommodating chamber 52, and to facilitate the placement of the sealing member 60 within the accommodating chamber 52. If problems such as blockage occur in the throttle hole 51 and the accommodating chamber 52, it is sufficient to replace the plug 70 directly without replacing the entire valve core 30. This also reduces processing costs and assembly difficulty, facilitating subsequent repairs and replacements.

[0067] It should be noted that, in this embodiment, Figure 1-Figure 2 As shown, the valve core 30 is provided with a receiving groove, which is used to accommodate the plug 70, and the inner wall of the receiving groove is provided with a thread, so that the plug 70 can be threadedly connected to the receiving groove of the valve core 30. Through the threaded connection, the plug 70 can be stably fixed in the receiving groove of the valve core 30, and is not easy to loosen or fall off; and the threaded connection is also convenient for subsequent maintenance and replacement. If problems such as blockage occur, the plug 70 can be easily removed to facilitate the replacement or repair of parts and improve maintenance efficiency. It is further explained that in other embodiments, the plug 70 can also be fixed by snap connection or by a locking member, and no other limitations are made in this embodiment.

[0068] In addition, if Figure 1-Figure 2 As shown, the elastic structure 80 also includes an elastic member 81 and a mounting member 82. The mounting member 82 is disposed within the valve sleeve 10. One end of the elastic member 81 abuts the second valve core segment 32, and the other end is connected to or abuts the mounting member 82. The elastic member 81 ensures that the valve core 30 can move to a desired position under varying pressures, thereby varying the size of the sealing area of ​​the oil return hole 12. The mounting member 82 provides stable support for the elastic member 81 and facilitates its installation.

[0069] It should be noted that, in this embodiment, the elastic member 81 is a spring. The spring's simple, inexpensive structure facilitates production and manufacturing, thus reducing costs. Furthermore, the mounting member 82 has a through-hole extending axially therethrough, allowing hydraulic oil entering through the oil inlet 11 to enter the valve sleeve 10 through this through-hole, thereby ensuring the subsequent hydraulic effect.

[0070] In addition, if Figure 1-Figure 2 As shown, the second valve core section 32 of the valve core 30 defines an accommodating cavity 34. At least a portion of the elastic member 81 extends into the accommodating cavity 34 and abuts against the bottom of the accommodating cavity 34. Providing the accommodating cavity 34 within the valve core 30 to house the elastic member 81 not only reduces the external dimensions of the entire pressure-compensating valve but also ensures a compact internal structure of the valve body.

[0071] like Figure 3-Figure 4As shown, this embodiment also provides a hydraulic control system, which includes a lifting cylinder 100 and a lifting module that controls the lifting cylinder 100 to perform lifting actions. The lifting module includes an oil inlet and an oil outlet. A solenoid valve 200 is arranged between the oil inlet and the oil inlet end of the lifting cylinder 100; a proportional flow valve 300 and the above-mentioned pressure compensation valve are sequentially arranged between the oil inlet end and the oil outlet of the lifting cylinder 100, the oil inlet hole 11 of the pressure compensation valve is connected to the proportional flow valve 300, the oil return hole 12 is connected to the oil outlet, and the feedback oil hole 13 is connected to the oil inlet end of the lifting cylinder 100.

[0072] like Figure 3 As shown, when lifting a load, hydraulic oil from the oil inlet (P) flows through solenoid valve 200 to the lift cylinder 100, completing the lifting action. When lowering the load, the proportional flow valve 300 is energized, and the hydraulic oil in the lift cylinder 100 flows through the proportional flow valve 300 and the pressure compensation valve, returning to the tank through the oil outlet (T), completing the lowering action. During this process, the proportional flow valve 300 controls the current flow and, in turn, the speed of the load's descent. The pressure compensation valve, through its structure, maintains a constant pressure differential across the proportional flow valve 300, ensuring that the descent speed is unaffected by the weight of the load and, therefore, the stability of the descent process.

[0073] like Figure 4 As shown, when a load needs to be held stationary at a certain height, the hydraulic oil in the lift cylinder 100 is shut off by the closed proportional flow valve 300, the pressure compensating valve, and the solenoid valve 200. The pressure compensating valve has a sealing portion 33, which forms a tight conical seal with the connecting corner 14, preventing hydraulic oil leakage and ensuring good stability of the hydraulic system when holding the load. Furthermore, the pressure compensating valve's one-way throttling passage maintains the stability of the positive valve core 30 during pressure compensation, resulting in excellent performance.

[0074] It should be noted here that, in this embodiment, a filter screen 400 is further provided between the solenoid valve 200 and the proportional flow valve 300. The filter screen 400 can effectively filter out fine impurities in the hydraulic oil, thereby preventing the fine impurities from clogging small holes or flow channels. At the same time, it can also prevent damage to other equipment during the circulation process, thereby ensuring good hydraulic circulation and extending the service life of the equipment.

[0075] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A pressure compensating valve, characterized in that: include: A valve sleeve (10), the valve sleeve (10) having an oil inlet hole (11), an oil return hole (12), and a feedback oil hole (13); an inner wall of the valve sleeve (10) is provided with a connecting corner (14), and the connecting corner (14) is located between the oil return hole (12) and the feedback oil hole (13); a valve seat (20), connected to the valve sleeve (10); A valve core (30) is slidably arranged in the valve sleeve (10) along the axial direction to block or open the oil return hole (12). The valve core (30) has a first valve core section (31) and a second valve core section (32). The first valve core section (31) and the valve seat (20) form a first chamber (41). An oil gap (42) is provided between the first valve core section (31) and the valve seat (20). The oil gap (42) communicates with the first chamber (41) and the feedback oil hole (13). A sealing portion (33) is provided between the first valve core section (31) and the second valve core section (32). The sealing portion (33) can abut against the connecting corner (14) to block the gap between the valve sleeve (10) and the valve core (30) between the oil return hole (12) and the feedback oil hole (13).

2. The pressure compensating valve according to claim 1, characterized in that The valve sleeve (10) comprises a first body (15) and a second body (16) connected to each other in the axial direction, the inner diameter of the first body (15) is larger than the inner diameter of the second body (16), and a connection angle (14) is formed at the connection between the first body (15) and the second body (16).

3. The pressure compensating valve according to claim 2, characterized in that The diameter of the first valve core section (31) is greater than the diameter of the second valve core section (32); the first valve core section (31) and the second valve core section (32) are connected via a tapered section; the outer diameter of one end of the tapered section connected to the first valve core section (31) is greater than the outer diameter of one end of the tapered section connected to the second valve core section (32); the circumferential surface of the tapered section forms the sealing portion (33); the first valve core section (31) is located in the first main body (15), and the second valve core section (32) is in sliding guide cooperation with the second main body (16).

4. The pressure compensating valve according to claim 3, characterized in that Along the axial direction of the valve core (30), the oil gap (42) is arranged in the form of an annular cavity between the valve core (30) and the valve seat (20), and the single-side size of the oil gap (42) is 0.2-0.5 mm.

5. The pressure compensating valve according to claim 3, characterized in that: The invention comprises an oil passage groove, wherein the oil passage groove is located on the valve seat (20) and / or the valve core (30). When the oil passage groove is located on the valve seat (20), the groove wall of the oil passage groove is recessed relative to the inner wall of the valve seat (20) toward the side away from the valve core (30) to form the oil passage gap (42); when the oil passage groove is located on the valve core (30), the wall of the oil passage groove is recessed relative to the surface of the valve core (30) toward the side away from the valve seat (20) to form the oil passage gap (42).

6. The pressure compensating valve according to claim 1, characterized in that The first valve core section (31) is provided with a one-way throttling channel connected to the first chamber (41) and the feedback oil hole (13), and a blocking member (60) is provided in the one-way throttling channel. The blocking member (60) is used to control the one-way flow of hydraulic oil from the first chamber (41) to the one-way throttling channel.

7. The pressure compensating valve according to claim 6, characterized in that The one-way throttling passage comprises a throttling hole (51), an accommodating chamber (52), and an oil passage (53) which are connected in sequence. The other end of the throttling hole (51) is connected to the first chamber (41), and the other end of the oil passage (53) is connected to the feedback oil hole (13). The blocking member (60) is arranged in the accommodating chamber (52). The blocking member (60) is used to disconnect or connect the throttling hole (51) and the accommodating chamber (52).

8. The pressure compensating valve according to claim 7, characterized in that The oil passage (53) includes a first oil passage hole (531), a second oil passage hole (532) and an annular groove (533) which are connected in sequence; the first oil passage hole (531) is arranged along the axial direction of the valve core (30), the second oil passage hole (532) is arranged along the radial direction of the valve core (30), and the annular groove (533) is arranged along the circumference of the valve core (30), and the other end of the first oil passage hole (531) is connected to the accommodating chamber (52), and the annular groove (533) is connected to both the feedback oil hole (13) and the oil passage gap (42).

9. The pressure compensating valve according to claim 8, characterized in that The pressure compensation valve further comprises a plug (70), wherein the plug (70) is arranged in the first valve core section (31) of the valve core (30), and the throttle hole (51) and the accommodating cavity (52) are both opened in the plug (70).

10. A hydraulic control system, characterized in that: include: A lifting cylinder (100) and a lifting module for controlling the lifting cylinder (100) to perform lifting actions, wherein the lifting module comprises an oil inlet and an oil outlet, and a solenoid valve (200) is provided between the oil inlet and the oil inlet end of the lifting cylinder; A proportional flow valve (300) and a pressure compensation valve as described in any one of claims 1 to 9 are sequentially arranged between the oil inlet end and the oil outlet of the lifting cylinder (100), the oil inlet hole (11) of the pressure compensation valve is connected to the proportional flow valve (300), the oil return hole (12) is connected to the oil outlet, and the feedback oil hole (13) is connected to the oil inlet end of the lifting cylinder (100).

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