Proportioning valve

Abstract

The application relates to the technical field of valves and discloses a proportional control valve which comprises a magnetic conducting sleeve, a moving iron, a stop iron, a main valve sleeve and a sliding valve core. The magnetic conducting sleeve is provided with a first through hole. The moving iron is movably arranged in the first through hole. The stop iron is fixedly arranged in the first through hole. The main valve sleeve is arranged in the magnetic conducting sleeve and partially located in the first through hole. The main valve sleeve is provided with an oil inlet, an oil return port, a cavity and a plurality of load ports. The sliding valve core is arranged in the cavity and fixedly connected with the moving iron. The sliding valve core is provided with a first hole part. The sliding valve core is movable relative to the main valve sleeve so that the first hole part is selectively communicated with any load port. The sliding valve core further comprises a second hole part and a pressure balance pipe. The second hole part penetrates one end of the sliding valve core close to the stop iron and is communicated with the first through hole. The pressure balance pipe is communicated with the first hole part and the second hole part. At least part of the pressure balance pipe is arranged in the first hole part and extends along the axial direction of the first hole part. The proportional control valve disclosed by the application improves the working stability.

Description

Technical Field

[0001] This application relates to the field of valve technology, and more particularly to a proportional control valve. Background Technology

[0002] Proportional control valves are control elements in hydraulic systems. They can be used to control the direction and speed of piston rod extension and retraction in hydraulic cylinders, as well as the forward and reverse rotation and speed of hydraulic motors. Furthermore, they allow the piston rod of the hydraulic cylinder or the motor to freely reverse direction without obstruction, even without a control signal. They are primarily used for the rotation and manual leveling of work platforms on aerial work platforms to control the vertical, horizontal, and speed movements of the platform. They can also be used for the forward, backward, and speed regulation of vehicles.

[0003] Therefore, improving the operational stability of proportional control valves is a technical problem that urgently needs to be solved. Utility Model Content

[0004] This application provides a proportional control valve, which improves operational stability.

[0005] To achieve the above objectives, the main technical solutions adopted in this application include: In a first aspect, this application provides a proportional control valve, including a magnetic sleeve, a moving iron, a stop, a main valve sleeve, and a spool valve core; the magnetic sleeve has a first through hole; the moving iron is movably disposed in the first through hole; the stop is fixedly installed in the first through hole; the main valve sleeve is disposed in the magnetic sleeve and partially located in the first through hole, the main valve sleeve has an oil inlet, an oil return port, a cavity, and multiple load ports, the oil inlet, the oil return port, the cavity, and the multiple load ports are interconnected; the spool valve core is disposed in the cavity and fixedly connected to the moving iron, the spool valve core has a first hole portion, the first hole portion is connected to the oil return port, the spool valve core is movable relative to the main valve sleeve so that the first hole portion can selectively connect to any load port; wherein, the spool valve core further includes a second hole portion and a pressure balance tube, the second hole portion penetrates through one end of the spool valve core near the stop and is connected to the first through hole, the pressure balance tube connects the first hole portion and the second hole portion, at least a portion of the pressure balance tube is disposed in the first hole portion and extends axially along the first hole portion.

[0006] According to the proportional control valve proposed in this application, the pressure on both sides of the valve core can be balanced, reducing the additional hydraulic pressure caused by excessive pressure difference between the two sides, reducing the occurrence of unbalanced forces on the valve core, reducing the unexpected impact of oil pressure changes on the movement of the valve core, and improving the response speed, action stability and position control accuracy of the valve core.

[0007] Optionally, the side wall of the spool valve core is provided with a first oil passage hole, which connects the first bore and the cavity. The side wall of the pressure balance tube is provided with a damping hole, which is arranged opposite to the first oil passage hole along the radial direction of the first bore.

[0008] In the above scheme, the above structure can produce a throttling damping effect, which can buffer instantaneous pressure fluctuations in the cavity and suppress hydraulic shocks caused by sudden changes in flow rate; at the same time, it facilitates more high-pressure oil to enter the cavity through the damping hole and the first oil passage hole, reducing the occurrence of unbalanced forces on the spool valve core.

[0009] Optionally, along the axial direction of the first hole, the pressure balance tube has a first end face away from the stop iron, and the distance between the first end face and the axis of the first oil passage is h1, where h1 satisfies: 2mm≤h1≤4mm.

[0010] In the above scheme, the above structure can reduce the occurrence of unbalanced forces on the spool valve core and improve the overall working stability and control accuracy of the proportional control valve.

[0011] Optionally, the diameter of the damping orifice is d1, where d1 satisfies: 0.3mm≤d1≤0.5mm.

[0012] In the above scheme, on the one hand, it can ensure that the damping orifice has a reasonable flow area and ensure the flow efficiency of the pressure medium in the pressure balance circuit. On the other hand, it can form an effective throttling damping effect and fully attenuate the pressure pulsation and flow fluctuation in the oil.

[0013] Optionally, the diameter of the first oil passage is d2, where d2 satisfies: 1.5mm≤d2≤2.5mm.

[0014] The above solution ensures smooth flow of oil between the cavity and the first hole, while avoiding hydraulic shock caused by a large flow of oil.

[0015] Optionally, along the axial direction of the first hole, the distance between the axis of the damping hole and the axis of the first oil passage hole is h2, where h2 satisfies: 0mm≤h2≤1mm.

[0016] In the above scheme, on the one hand, it can ensure that enough high-pressure oil enters the second hole, and on the other hand, it can make the throttling and damping effect of the damping hole uniform and stable, which can effectively reduce the pressure pulsation and flow fluctuation in the oil.

[0017] Optionally, the inner diameter of the pressure balancing tube is d3, where d3 satisfies: 0.9mm≤d3≤1.3mm; and the outer diameter of the pressure balancing tube is d4, where d4 satisfies: 1.6mm≤d4≤1.7mm.

[0018] The above solution can ensure sufficient flow cross-sectional area in the pipe and effectively improve the operational stability and control accuracy of the proportional control valve.

[0019] Optionally, there are multiple first oil passages, which are spaced apart along the circumference of the first hole portion.

[0020] In the above scheme, the above structure helps to form a circumferentially symmetrical pressure field and flow field, effectively reducing the radial unbalanced liquid pressure acting on the spool valve core.

[0021] Optionally, there are multiple damping holes, which are spaced apart along the circumference of the first hole portion.

[0022] In the above scheme, the above structure helps to further reduce the unbalanced fluid pressure on the valve core and improve the working stability of the valve core.

[0023] Optionally, the number of first oil passage holes is greater than the number of damping holes.

[0024] In the above scheme, the above structure can effectively reduce the radial unbalanced hydraulic pressure on the spool valve core and maintain the stable operation of the spool valve core.

[0025] The beneficial effects of this application are: it can balance the pressure on both sides of the valve core, reduce the additional hydraulic pressure caused by excessive pressure difference on both sides, reduce the occurrence of unbalanced forces on the valve core, reduce the unexpected impact of oil pressure changes on the movement of the valve core, and help improve the response speed, action stability and position control accuracy of the valve core. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the overall structure of the proportional control valve in some embodiments of this application; Figure 2 This is a front view schematic diagram of the proportional control valve in some embodiments of this application; Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along the AA direction; Figure 4 for Figure 3 A magnified structural diagram at point B in the middle.

[0028] [Explanation of Labels in the Attached Image] 100. Magnetic sleeve; 101. First through hole; 200. Moving iron; 300. Stop; 400. Main valve sleeve; 401. Oil inlet; 402. Cavity; 403. Oil return port; 404. Load port; 500, valve core; 501, first hole; 502, second hole; 503, first oil passage hole; 510. Pressure balance tube; 511. Damping orifice; 512. First end face; 600, push rod. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification and the foregoing drawings are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification or the foregoing drawings are used to distinguish different objects, not to describe a specific order or hierarchy.

[0031] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] In this application, "multiple" means two or more (including two).

[0034] The control element in a hydraulic system can be used to control the direction and speed of the piston rod extension and retraction of a hydraulic cylinder, as well as the forward and reverse rotation and speed adjustment of a hydraulic motor. Furthermore, it has the characteristic of allowing the piston rod of the hydraulic cylinder or the motor to freely reverse direction without obstruction, even without a control signal. It is mainly used for the rotation and manual leveling of the work platform on aerial work platforms to achieve up-and-down, left-and-right movement and speed control of the work platform. It can also be used for the forward and backward movement and speed adjustment of the vehicle.

[0035] In actual operation, the valve is affected by the flow rate, which can cause an imbalance in the force on the spool valve core, leading to abnormal performance of the entire valve.

[0036] In view of this, in order to improve the working stability of the proportional control valve, this application proposes a proportional control valve in which the spool also includes a second hole and a pressure balance tube. The second hole penetrates the end of the spool near the stop and communicates with the first through hole. The pressure balance tube connects the first hole and the second hole. At least a portion of the pressure balance tube is disposed in the first hole and extends axially along the first hole, which helps to balance the hydraulic force borne by both ends of the spool, reduce the unbalanced hydraulic pressure on the spool during valve operation, effectively reduce the occurrence of unbalanced force caused by changes in medium flow rate and liquid flow impact, weaken the adverse effects of flow fluctuation on the stress state of the spool, ensure smooth movement of the spool within the valve sleeve, thereby improving the working stability and control accuracy of the entire valve and extending the service life of the spool and valve sleeve.

[0037] The following describes in detail, with reference to the accompanying drawings, a proportional control valve proposed in the embodiments of this application.

[0038] like Figure 1 , Figure 2 and Figure 3 As shown, the proportional control valve proposed in this application embodiment includes a magnetic sleeve 100, a moving iron 200, a stop iron 300, a main valve sleeve 400, and a spool valve core 500.

[0039] The magnetic sleeve 100 has a first through hole 101; the moving iron 200 is movably disposed in the first through hole 101; the stop iron 300 is fixedly installed in the first through hole 101; specifically, the first through hole 101 passes through the magnetic sleeve 100, the moving iron 200 and the stop iron 300 are sequentially disposed in the first through hole 101, and a stepped surface is provided on the inner wall of the first through hole 101 to limit the displacement of the stop iron 300. A coil is sleeved on the outer side of the magnetic sleeve 100. After the coil is energized, it magnetizes the moving iron 200 through a magnetic field, causing the moving iron 200 to generate magnetism and move toward or away from the stop iron 300.

[0040] The main valve sleeve 400 is disposed on the magnetic sleeve 100 and partially located in the first through hole 101. The main valve sleeve 400 has an oil inlet 401, an oil return port 403, a cavity 402, and multiple load ports 404. The oil inlet 401, the oil return port 403, the cavity 402, and the multiple load ports 404 are interconnected. High-pressure oil flows through each of the multiple load ports 404. The oil return port 403 can be selectively connected to any load port 404. High-pressure oil can flow from the oil inlet 401 to the corresponding load port 404 and flow out from other load ports 404. At the same time, high-pressure oil flowing out from other load ports 404 can flow to the oil return port 403 and return to the oil tank.

[0041] The spool valve core 500 is disposed in the cavity 402 and fixedly connected to the moving iron 200. The spool valve core 500 has a first hole 501, which communicates with the oil return port 403. The spool valve core 500 is movable relative to the main valve sleeve 400 so that the first hole 501 can selectively communicate with any load port 404. It can be understood that the spool valve core 500 is located on the side of the stop iron 300 away from the moving iron 200. The spool valve core 500 can be connected to the moving iron 200 through the push rod 600 to form a whole. When the moving iron 200 approaches or moves away from the stop iron 300, it can drive the spool valve core 500 to move in the direction of approaching or moving away from the stop iron 300.

[0042] Specifically, the first hole 501 opens towards the side of the spool valve core 500 away from the stop 300, allowing high-pressure oil to flow through the first hole 501 to the return port 403 and then back to the oil tank.

[0043] The slide valve core 500 also includes a second hole 502 and a pressure balancing tube 510. The second hole 502 penetrates one end of the slide valve core 500 near the stop 300 and communicates with the first through hole 101. The pressure balancing tube 510 connects the first hole 501 and the second hole 502. At least a portion of the pressure balancing tube 510 is disposed in the first hole 501 and extends axially along the first hole 501.

[0044] When the spool valve 500 moves or the working pressure inside the proportional control valve changes, the oil in the first orifice 501 can flow through the pressure balance pipe 510 to the second orifice 502, and then from the second orifice 502 to the space between the spool valve 500 and the stop 300. This helps to balance the pressure on both sides of the spool valve 500, reduce the additional hydraulic pressure caused by the excessive pressure difference between the two sides, and reduce the occurrence of unbalanced forces on the spool valve 500.

[0045] The pressure balancing pipe 510 extends axially along the first through hole 101, which helps to align the extension direction of the pressure balancing pipe 510 with the movement direction of the spool valve 500, shortening the path of the pressure balancing channel and reducing the turning and local resistance during oil flow. This reduces the hydraulic resistance experienced by the spool valve 500 during movement, preventing the formation of a closed cavity due to the inability to replenish or discharge oil in a timely manner, and reducing the risk of hydraulic lock-up or movement sluggishness.

[0046] During the operation of the proportional control valve, the spool 500 typically needs to move axially based on the balance between electromagnetic force, spring force, and hydraulic pressure. Connecting the first orifice 501 and the second orifice 502 via the pressure balance pipe 510 reduces the unintended impact of oil pressure changes on the movement of the spool 500. This allows the position change of the spool 500 to be more influenced by the control current and the preset spring force, thus improving the spool 500's response speed, operational stability, and position control accuracy.

[0047] In some embodiments, such as Figure 4 As shown, the side wall of the slide valve core 500 is provided with a first oil passage hole 503, which connects the first hole portion 501 and the cavity 402. The side wall of the pressure balance tube 510 is provided with a damping hole 511, which is arranged opposite to the first oil passage hole 503 along the radial direction of the first hole portion 501.

[0048] On the one hand, the oil can generate a throttling damping effect when passing through the damping hole 511, which can buffer the instantaneous pressure fluctuation in the cavity 402 and suppress the hydraulic shock caused by the sudden change in flow. On the other hand, it facilitates more high-pressure oil to enter the cavity 402 through the damping hole 511 and the first oil passage 503, which plays a role in stabilizing pressure and buffering, reducing the occurrence of unbalanced forces on the spool valve core 500, making the pressure regulation at both ends of the spool valve core 500 more gradual and balanced, improving the response stability of the pressure balance circuit of the spool valve core 500, reducing the interference of flow disturbance on the output performance of the proportional control valve, ensuring the smooth movement of the spool valve core 500, and further improving the control accuracy and working reliability of the proportional control valve under variable flow conditions.

[0049] In some embodiments, such as Figure 4As shown, along the axial direction of the first hole 501, the pressure balance tube 510 has a first end face 512 away from the stop 300. The distance between the first end face 512 and the axis of the first oil passage 503 is h1, and h1 satisfies: 2mm≤h1≤4mm.

[0050] Since h1 meets the above range, on the one hand, it can ensure that enough high-pressure oil enters the second hole 502, avoid the pressure on the right side of the spool 500 being too high, thereby causing an imbalance between the pressure on the left side and the right side of the spool 500, reducing the occurrence of unbalanced forces on the spool 500, and improving the overall working stability and control accuracy of the proportional control valve.

[0051] On the other hand, it can prevent the first end face 512 from being too far from the first oil passage 503, and avoid the first end face 512 from being too close to the low pressure flow area, causing too much oil from the low pressure flow area to enter the second hole 502, thereby causing an imbalance between the pressure on the left side of the spool 500 and the pressure on the right side of the spool 500, reducing the occurrence of unbalanced forces on the spool 500, and improving the overall working stability and control accuracy of the proportional control valve.

[0052] Optionally, h1 can be 2mm, 2.1mm, 2.3mm, 2.5mm, 2.7mm, 2.9mm, 3mm, 3.1mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, or 4mm.

[0053] In some embodiments, such as Figure 4 As shown, the diameter of the damping orifice 511 is d1, and d1 satisfies: 0.3mm≤d1≤0.5mm.

[0054] Since d1 meets the above range, on the one hand, it can ensure that the damping orifice 511 has a reasonable flow area, ensure the flow efficiency of the pressure medium in the pressure balance circuit, enable the pressure change at both ends of the spool 500 to be transmitted quickly and compensated and matched in time, avoid the pressure transmission lag causing a continuous pressure difference at both ends of the spool 500, ensure the response speed of the pressure balance structure, and enable the spool 500 to quickly adjust to the force balance state according to the change of working conditions, and ensure the control response performance of the proportional control valve.

[0055] On the other hand, the damping orifice 511 can form an effective throttling damping effect, fully attenuating the pressure pulsation and flow fluctuation in the oil, weakening the disturbance of hydraulic shock on the force state of the spool 500, suppressing the axial vibration or radial displacement of the spool 500, making the pressure build-up process at both ends of the spool 500 smooth and stable, effectively reducing the unbalanced hydraulic pressure on the spool 500, and improving the stability and control accuracy of the proportional control valve during operation.

[0056] Optionally, d1 can be 0.3mm, 0.31mm, 0.33mm, 0.35mm, 0.37mm, 0.39mm, 0.4mm, 0.41mm, 0.44mm, 0.45mm, 0.46mm, 0.47mm, 0.48mm, 0.49mm, or 0.5mm.

[0057] In some embodiments, such as Figure 4 As shown, the diameter of the first oil passage 503 is d2, and d2 satisfies: 1.5mm≤d2≤2.5mm.

[0058] Since d2 meets the above range, on the one hand, it can ensure the smooth flow of oil between cavity 402 and first hole 501, and on the other hand, it can reduce the risk of channel blockage caused by small impurities in the oil, and improve the reliability of valve operation.

[0059] On the other hand, it can avoid hydraulic shock caused by large flow of oil, which helps to maintain stable pressure at both ends of the spool 500. At the same time, it can control the lateral force on the side wall of the spool 500 when the oil flows through the oil passage, avoiding the increase of lateral unbalanced load on the spool 500 due to excessively large oil passage diameter and high oil flow force. It can also ensure the structural strength at the opening of the spool 500, preventing the side wall from weakening due to excessively large opening, and ensuring the structural stability of the spool 500 during long-term operation.

[0060] Optionally, d2 can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, or 2.5mm.

[0061] In some embodiments, such as Figure 4 As shown, along the axial direction of the first hole 501, the distance between the axis of the damping hole 511 and the axis of the first oil passage 503 is h2, and h2 satisfies: 0mm≤h2≤1mm.

[0062] Since h2 meets the above range, the damping hole 511 and the first oil passage hole 503 can be kept highly aligned in the radial direction. After the oil enters the first hole 501 from the first oil passage hole 503, it can flow directly into the opposite damping hole 511, ensuring that enough high-pressure oil enters the second hole 502. The oil flow path is short and the flow direction is smooth, with low flow resistance. The pressure change on the cavity 402 side can be quickly and smoothly transmitted to the inside of the pressure balance tube 510, ensuring that the pressure compensation response at both ends of the slide valve core 500 is timely, ensuring that the pressure balance structure has a good response speed, so that the slide valve core 500 can quickly adjust to the force balance state according to the change of working conditions.

[0063] Meanwhile, this axial dimension limitation can prevent the oil flow from undergoing severe bending, shearing, and local eddies due to excessive axial misalignment between the two holes. It reduces the additional lateral unbalanced hydraulic pressure generated by flow field disturbances on the sidewall of the spool valve core 500, while ensuring that the throttling damping effect of the damping orifice 511 is uniform and stable. This can effectively attenuate pressure pulsations and flow fluctuations in the oil, fully exert the pressure stabilization and buffering effect, maintain stable pressure at both ends of the spool valve core 500, and improve the overall stability and control accuracy of the proportional control valve.

[0064] Optionally, h2 can be 0mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm.

[0065] In some embodiments, such as Figure 4 As shown, the inner diameter of the pressure balancing tube 510 is d3, which satisfies: 0.9mm≤d3≤1.3mm; the outer diameter of the pressure balancing tube 510 is d4, which satisfies: 1.6mm≤d4≤1.7mm.

[0066] Since d4 meets the above range, on the one hand, it can ensure that there is sufficient flow cross-sectional area in the pipe, so that the pressure medium can flow smoothly in the balanced pipeline, ensure that the pressure change at both ends of the slide valve core 500 can be transmitted quickly, ensure the response speed of pressure compensation, so that the pressure difference at both ends of the slide valve core 500 can be eliminated quickly, and continuously maintain the force balance of the slide valve core 500.

[0067] On the other hand, it can ensure that the damping orifice 511 has a stable and controllable attenuation effect on pressure pulsation and flow fluctuation, making the pressure regulation process at both ends of the spool 500 smooth and uniform, and effectively improving the operating stability and control accuracy of the proportional control valve.

[0068] Optionally, d3 can be 0.9mm, 0.91mm, 1mm, 1.05mm, 1.1mm, 1.14mm, 1.18mm, 1.2mm, 1.21mm, 1.25mm, 1.28mm, or 1.3mm.

[0069] Alternatively, d4 can be 1.6mm, 1.61mm, 1.63mm, 1.65mm, 1.67mm, or 1.7mm.

[0070] In some embodiments, there are multiple first oil passage holes 503, which are spaced apart along the circumference of the first hole portion 501. Specifically, there may be four first oil passage holes 503, which are arranged at equal intervals along the circumference of the first hole portion 501.

[0071] The circumferential multi-point oil passage allows the oil in the cavity 402 to flow evenly into the first hole 501 along the circumferential direction of the spool valve core 500. This forms a circumferentially symmetrical pressure field and flow field in the annular cavity between the pressure balance pipe 510 and the first hole 501, avoiding flow field deviation caused by unilateral oil inlet. This effectively weakens the radial unbalanced hydraulic pressure acting on the spool valve core 500, maintains the centering of the spool valve core 500's movement, reduces the risk of uneven wear and jamming between the spool valve core 500 and the valve sleeve, and improves the smoothness of the spool valve core 500's operation.

[0072] Multiple first oil passages 503 together provide sufficient total flow cross-sectional area, ensuring the oil flow efficiency between cavity 402 and pressure balance circuit, so that pressure changes on the cavity 402 side can be quickly transmitted to both ends of the spool 500, ensuring the response speed of pressure compensation; at the same time, there is no need to increase the orifice diameter of a single first oil passage 503, which can preserve the structural strength of the spool 500 sidewall, avoid weakening the mechanical properties of the spool 500 by excessively large openings, and improve the structural reliability of the spool 500.

[0073] Uniform circumferential oil inlet allows the oil to flow symmetrically and smoothly to the damping holes 511 on the side wall of the pressure balance pipe 510. The throttling damping effect of each damping hole 511 is uniform and consistent, which can more fully attenuate the pressure pulsation and flow fluctuation in the oil, enhance the pressure stabilization and buffering effect of the pressure balance circuit, and make the pressure regulation process at both ends of the slide valve core 500 more gradual and synchronous, further improving the control accuracy and working stability of the proportional control valve under variable flow conditions.

[0074] In some embodiments, there are multiple damping holes 511, which are spaced apart along the circumference of the first hole portion 501. In a specific embodiment, there are two damping holes 511, and the axes of the two damping holes 511 coincide. After the oil enters the first hole portion 501 through each first oil passage 503, it can simultaneously flow into the pressure balance pipe 510 through the uniformly distributed damping holes 511, so that the flow field and pressure field in the balance pipe are symmetrically distributed along the circumference. This avoids the flow field deviation and radial pressure difference caused by single-hole throttling or unilateral oil inlet, effectively weakens the lateral unbalanced fluid pressure on the slide valve core 500, maintains the centered operation of the slide valve core 500, reduces the risk of uneven wear and jamming between the slide valve core 500 and the valve sleeve, and improves the smoothness of the movement of the slide valve core 500.

[0075] Multiple damping orifices 511 work together to exert a throttling and damping effect. Based on the matching design of the total flow area, they can more effectively attenuate pressure pulsations and flow fluctuations in the oil, smooth the pressure regulation process at both ends of the slide valve core 500, enhance the pressure stabilization and buffering effect of the pressure balance circuit, and achieve higher control accuracy.

[0076] Uniform circumferential liquid inlet ensures a uniform and synchronous pressure build-up process within the pressure balance tube 510, avoiding additional axial forces caused by sudden local pressure changes. This ensures stable and consistent pressure compensation at both ends of the valve core 500, further reducing the axial unbalanced liquid pressure on the valve core 500 and improving the stability of the force balance of the valve core 500.

[0077] In some embodiments, the number of first oil passage holes 503 is greater than the number of damping holes 511. It is understood that a greater number of first oil passage holes 503 can create a denser network of oil inlets along the circumference of the valve core 500, allowing the oil in the cavity 402 to flow evenly and fully into the annular chamber between the first hole 501 and the pressure balance pipe 510. This ensures sufficient total flow area between the cavity 402 and the annular chamber, resulting in low oil flow resistance and fast pressure transmission response. It also enhances the symmetry of the pressure field within the annular chamber, effectively reducing the radial unbalanced hydraulic pressure on the valve core 500, maintaining stable operation of the valve core 500, and reducing the risk of uneven wear and jamming.

[0078] This can prevent the total flow area from being too large due to an excessive number of damping orifices 511, which would weaken the throttling and pressure stabilizing effect. It can also make the pressure regulation process at both ends of the spool 500 smooth and stable, ensuring the control accuracy and operational stability of the proportional control valve.

[0079] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A proportional control valve, characterized in that, include: The magnetic sleeve (100) has a first through hole (101); A movable iron (200) is movably disposed in the first through hole (101); A stop (300) is fixedly installed in the first through hole (101); A main valve sleeve (400) is disposed in the magnetic sleeve (100) and partially located in the first through hole (101). The main valve sleeve (400) has an oil inlet (401), an oil return port (403), a cavity (402), and a plurality of load ports (404). The oil inlet (401), the oil return port (403), the cavity (402), and the plurality of load ports (404) are connected to each other. A spool valve (500) is disposed in the cavity (402) and fixedly connected to the moving iron (200). The spool valve (500) has a first hole (501) which communicates with the oil return port (403). The spool valve (500) is movable relative to the main valve sleeve (400) so that the first hole (501) can be selectively connected to any of the load ports (404). The valve core (500) further includes a second hole (502) and a pressure balancing tube (510). The second hole (502) passes through one end of the valve core (500) near the stop (300) and communicates with the first through hole (101). The pressure balancing tube (510) connects the first hole (501) and the second hole (502). At least a portion of the pressure balancing tube (510) is disposed in the first hole (501) and extends axially along the first hole (501).

2. The proportional control valve according to claim 1, characterized in that, The side wall of the slide valve core (500) is provided with a first oil passage hole (503), which connects the first hole (501) and the cavity (402). The side wall of the pressure balance tube (510) is provided with a damping hole (511), which is arranged opposite to the first oil passage hole (503) along the radial direction of the first hole (501).

3. The proportional control valve according to claim 2, characterized in that, Along the axial direction of the first hole (501), the pressure balance tube (510) has a first end face (512) away from the stop (300), and the distance between the first end face (512) and the axis of the first oil passage (503) is h1, wherein h1 satisfies: 2mm≤h1≤4mm.

4. The proportional control valve according to claim 2, characterized in that, The diameter of the damping hole (511) is d1, and d1 satisfies: 0.3mm≤d1≤0.5mm.

5. The proportional control valve according to claim 4, characterized in that, The diameter of the first oil passage (503) is d2, and d2 satisfies: 1.5mm≤d2≤2.5mm.

6. The proportional control valve according to claim 5, characterized in that, Along the axial direction of the first hole (501), the distance between the axis of the damping hole (511) and the axis of the first oil passage hole (503) is h2, and h2 satisfies: 0mm≤h2≤1mm.

7. The proportional control valve according to claim 1, characterized in that, The inner diameter of the pressure balancing tube (510) is d3, and d3 satisfies: 0.9mm≤d3≤1.3mm; the outer diameter of the pressure balancing tube (510) is d4, and d4 satisfies: 1.6mm≤d4≤1.7mm.

8. The proportional control valve according to claim 2, characterized in that, There are multiple first oil passage holes (503), which are spaced apart along the circumference of the first hole portion (501).

9. The proportional control valve according to claim 8, characterized in that, There are multiple damping holes (511), which are spaced apart along the circumference of the first hole portion (501).

10. The proportional control valve according to claim 9, characterized in that, The number of the first oil passage holes (503) is greater than the number of the damping holes (511).

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