A proportional control valve

Abstract

This invention relates to the field of electro-hydraulic control technology, and more particularly to a proportional control valve, which includes a main valve component and a pilot component. The main valve component includes a hydraulically controlled main valve core, and the pilot component includes a first pilot mechanism and a second pilot mechanism with identical structures. The first and second pilot mechanisms are coaxially disposed at both ends of the hydraulically controlled main valve core. A first control cavity and a second control cavity are also provided at both ends of the hydraulically controlled main valve core. The inlet of the first pilot mechanism is connected to the main inlet, the first control cavity is connected to the inlet of the second pilot mechanism, and the second control cavity is connected to a low-pressure return port or an oil tank. By controlling the displacement and speed of the first and second pilot mechanisms, the opening amount, speed, flow rate, and continuous smooth control of the hydraulically controlled main valve core when it opens or closes are achieved.

Description

Technical Field

[0001] This invention relates to the field of electro-hydraulic control technology, and in particular to a proportional control valve. Background Technology

[0002] Currently, all hydraulic cylinders in coal mine hydraulic supports are controlled using high-flow-rate water-based on-off valves. Because the flow rate cannot be continuously and smoothly controlled, this not only causes significant mechanical, pressure, and flow shocks that damage the support or hydraulic system, but also leads to inaccurate position control of the hydraulic cylinders, affecting the support's posture and its coupling with the surrounding rock, and impacting the support's level of intelligence. Therefore, to achieve intelligent, safe, stable, and efficient hydraulic support, it is urgent to transform the existing on-off control technology to achieve continuous and smooth flow rate control.

[0003] Proportional control technology is the fundamental way to solve the above problems, and the proportional control valve is the key to realizing this technology. Therefore, this invention proposes a novel high-flow-rate water-based proportional control valve. This valve can precisely, continuously, and smoothly adjust the valve orifice size and flow rate, solving the various impact problems and inaccurate hydraulic cylinder positioning issues caused by existing electro-hydraulic switching valves, as well as the low control accuracy of the main valve orifice size in existing pilot-operated water-based proportional valves. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a proportional control valve that can improve the control accuracy of the valve orifice size of the hydraulic main valve core and achieve continuous and smooth flow control.

[0005] This invention provides a proportional control valve, comprising:

[0006] The main valve assembly includes a hydraulically controlled main valve core;

[0007] The pilot component includes a first pilot mechanism and a second pilot mechanism with identical structures. The first pilot mechanism and the second pilot mechanism are coaxially and oppositely disposed at both ends of the hydraulic main valve core. The two ends of the hydraulic main valve core are also provided with a first control cavity and a second control cavity. The liquid inlet of the first pilot mechanism is connected to the main liquid inlet of the main valve component. The first control cavity is connected to the liquid inlet of the second pilot mechanism. The second control cavity is connected to the low-pressure return port or the oil tank.

[0008] Optionally, the first pilot mechanism and the second pilot mechanism act on both ends of the hydraulic main valve core through reciprocating linear motion along the axis of the hydraulic main valve core. Both the first pilot mechanism and the second pilot mechanism include a pilot valve seat and a pilot valve core, and the pilot valve core is coaxially disposed in the pilot valve seat.

[0009] One end of the pilot valve core is connected to a pilot flexural component, and the other end of the pilot valve core is provided with a first axial through hole at the position corresponding to the central axis of the pilot valve seat. A push rod coaxial with the pilot valve core and capable of reciprocating motion is inserted in the first axial through hole. The push rod is clearance-fitted with the first axial through hole. A radial liquid inlet hole is provided at the other end of the pilot valve seat near the pilot valve core.

[0010] Optionally, the two ends of the hydraulic main valve core are sequentially provided with a clamping plug and the pilot component along the axial direction. The clamping plug has a polygonal central hole in the axial direction to accommodate the push rod, and a radial gap is left between the polygonal central hole and the push rod.

[0011] Optionally, the push rods are respectively connected to a power mechanism capable of outputting linear motion. The power mechanism is a proportional electromagnet, or a linear motor, or a stepper motor or servo motor with a lead screw and nut mechanism, or an electric cylinder composed of a motor and a lead screw and nut, or a hydraulic control circuit.

[0012] Optionally, the hydraulic main valve core is provided with a first radial hole and a second radial hole at both ends, and the first radial hole and the second radial hole are respectively connected to the liquid inlet of the first pilot mechanism and the liquid inlet of the second pilot mechanism.

[0013] The hydraulic main valve core is provided with a first annular groove and a second annular groove at the positions corresponding to the first radial small hole and the second radial small hole, and the first radial small hole and the first annular groove are connected, and the second radial small hole and the second annular groove are connected.

[0014] Optionally, the main valve component further includes a main outlet valve sleeve, a main valve seat, and a high-pressure valve sleeve;

[0015] The hydraulic main valve core includes a valve core body, on which a truncated cone is provided. One side of the truncated cone is a first valve stem, and the other side is a second valve stem. The first valve stem is disposed inside the main outlet valve sleeve, and the end face of the first valve stem and the main outlet valve sleeve form the first control cavity.

[0016] The second valve stem is disposed inside the high-pressure valve sleeve, and a second control cavity is formed between the end face of the second valve stem and the high-pressure valve sleeve.

[0017] Optionally, the main valve component is a two-position two-way structure, and the main outlet valve sleeve is provided with a first radial hole, a second radial hole and a working port;

[0018] The high-pressure valve sleeve is provided with a third radial hole, a fourth radial hole and the main liquid inlet;

[0019] The inner side of the first radial hole is connected to the first control cavity, and the outer side of the first radial hole is connected to the outer side of the third radial hole through an oil passage.

[0020] The inner side of the second radial hole is connected to the first annular groove, and the outer side of the second radial hole is connected to the main liquid inlet;

[0021] The inner side of the third radial hole is connected to the second annular groove;

[0022] The inner side of the fourth radial hole is connected to the second control cavity, and the outer side of the fourth radial hole is connected to the low-pressure return oil channel or the oil tank.

[0023] Optionally, the main valve component is a two-position three-way structure, and the main valve component also includes a sleeve valve core, a check valve, and a switching valve;

[0024] The main outlet valve sleeve is provided with a first radial hole, a second radial hole, a fifth radial hole, and a main return port;

[0025] The sleeve valve core is fitted onto the first valve stem, and one end of it is in contact with the annular stepped surface of the main outlet valve sleeve;

[0026] The main valve seat is provided with a radial working port;

[0027] The high-pressure valve sleeve is provided with a third radial hole, a fourth radial hole and a main liquid inlet;

[0028] The inner side of the first radial hole is connected to the first control cavity, and the outer side of the first radial hole is connected to the inlet of the one-way valve through an oil passage.

[0029] The inner side of the second radial hole is connected to the first annular groove, and the outer side of the second radial hole is connected to the main liquid inlet;

[0030] The inner side of the fifth radial hole is connected to the sleeve valve core through an oil passage, and the outer side of the fifth radial hole is connected to the outlet of the one-way valve through an oil passage.

[0031] The inner side of the third radial hole is connected to the second annular groove, and the outer side of the third radial hole is connected to the outlet of the one-way valve through an oil passage.

[0032] The inner side of the fourth radial hole is connected to the second control cavity, and the outer side of the fourth radial hole is connected to the low-pressure return oil channel or the oil tank.

[0033] The switching valve is a two-position normally open valve. The inlet of the switching valve is connected to the outlet of the check valve through an oil passage, and the outlet of the switching valve is connected to the low-pressure return oil passage or the oil tank.

[0034] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art:

[0035] This embodiment provides a proportional control valve. High-pressure fluid enters the first pilot mechanism through the main inlet, thereby entering the first control chamber. The first control chamber is connected to the inlet of the second pilot mechanism, allowing the high-pressure fluid entering the first control chamber to enter the second pilot mechanism. The second control chamber is connected to the low-pressure return port or the oil tank. By controlling the displacement and speed of the first and second pilot mechanisms, the opening amount, speed, flow rate, and continuous smooth control of the hydraulic main valve core when it is opened or closed can be achieved. This reduces the mechanical and pressure / flow impact of the hydraulic support and achieves precise control of the hydraulic support. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of a proportional control valve with a two-position two-way main valve component, as described in an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of a proportional control valve with a two-position three-way main valve component, as described in an embodiment of the present invention.

[0040] The components include: 1. Main outlet valve sleeve; 2. Main valve seat; 3. High-pressure valve sleeve; 4. Main spring; 5. Hydraulic main valve core; 5.1. Cone; 5.2. First valve stem; 5.3. Second valve stem; 6. Lower valve seat; 7. Pilot-operated tumbler; 8. Spring seat; 9. Small ball; 10. Upper valve seat; 11. Compression plug; 12. Push rod; 13. Screw and nut mechanism; 14. Servo motor; 15. First control cavity; 16. Second control cavity; 17. Check valve; 18. Sleeve valve core; 19. Switch valve; a. First radial orifice; b. Second radial orifice; k1. First radial orifice; k2. Second radial orifice; k3. Third radial orifice; k4. Fourth radial orifice; k5. Fifth radial orifice; A. Working port; P. Main inlet; O. Main return port. Detailed Implementation

[0041] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0042] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0043] Example 1:

[0044] Reference Figure 1 As shown, an embodiment of the present invention provides a proportional control valve, including a main valve component and a pilot component, wherein the main valve component is a two-position two-way structure.

[0045] The main valve component includes a hydraulically controlled main valve core 5, and the pilot component includes a first pilot mechanism and a second pilot mechanism with the same structure. The first pilot mechanism and the second pilot mechanism are respectively coaxially and oppositely arranged at both ends of the hydraulically controlled main valve core 5. The first pilot mechanism and the second pilot mechanism act on both ends of the hydraulically controlled main valve core 5 through reciprocating linear motion along the axis of the hydraulically controlled main valve core. The two ends of the hydraulically controlled main valve core 5 are also provided with a first control cavity 15 and a second control cavity 16. The liquid inlet of the first pilot mechanism is connected to the main liquid inlet P, the first control cavity 15 is connected to the liquid inlet of the second pilot mechanism, and the second control cavity 16 is connected to the low-pressure return port or the oil tank. Specifically, the first pilot mechanism and the second pilot mechanism have the same structure, both being two-position two-way structures. The first pilot mechanism and the second pilot mechanism are respectively provided at both ends of the hydraulic main valve core 5, and the first pilot mechanism and the second pilot mechanism are coaxially arranged with the hydraulic main valve core 5. The first control cavity 15 is located at one end of the hydraulic main valve core 5 relative to the first pilot mechanism, and the second control cavity 16 is located at the other end of the hydraulic main valve core 5 relative to the second pilot mechanism. The first pilot mechanism is connected to the first control cavity 15, and the second pilot mechanism is connected to the second control cavity 16. The liquid inlet of the first pilot mechanism is connected to the main liquid inlet P, so that the high-pressure liquid enters the first pilot mechanism through the main liquid inlet P, and then enters the first control cavity 15. The first control cavity 15 is connected to the liquid inlet of the second pilot mechanism, so that the high-pressure liquid entering the first control cavity 15 can enter the second pilot mechanism, and then enter the second control cavity 16. The second control cavity 16 is connected to the low-pressure return port or the oil tank. In other words, the first and second pilot mechanisms are driven by a power mechanism to move along the axial direction of the hydraulic main valve core 5 to achieve two states. In the first state, high-pressure fluid enters the first control chamber 15. When the pressure inside the first control chamber 15 rises to the opening pressure, the hydraulic main valve core 5 moves along its axial direction until it reaches its maximum opening. In the second state, the high-pressure fluid in the first control chamber 15 enters the second control chamber 16, and the hydraulic main valve core 5 moves in the opposite direction to that in the first state until its opening is closed to zero. That is, by controlling the displacement and speed of the first and second pilot mechanisms, the opening, speed, flow rate, and continuous smooth control of the hydraulic main valve core 5 when it opens or closes can be achieved, reducing the mechanical and pressure / flow impact on the hydraulic support and realizing precise control of the hydraulic support.

[0046] Furthermore, both the first pilot mechanism and the second pilot mechanism include a pilot valve seat and a pilot valve core, with the pilot valve core coaxially disposed within the pilot valve seat; one end of the pilot valve core is connected to the pilot flexural component 7, and the other end of the pilot valve core is provided with a first axial through hole at the position corresponding to the central axis of the pilot valve seat, and a push rod 12 coaxial with the pilot valve core and capable of reciprocating motion is inserted into the first axial through hole, with the push rod 12 and the first axial through hole having clearance fit. Specifically, the pilot valve core is located inside the pilot valve seat and is coaxially arranged with the pilot valve seat. One end of the pilot valve core is connected to a pilot spring 7, which prevents the pilot valve core from directly contacting one end of the pilot valve seat with a large impact force during movement, thus avoiding damage to both the pilot valve core and the pilot valve seat. The pilot spring 7 can be a spring or any component that can provide a buffering effect. The other end of the pilot valve core has a first axial through hole at the position corresponding to the central axis of the pilot valve seat, and the pilot valve seat has a second axial through hole at the position corresponding to the first axial through hole. The second axial through hole is aligned with the first axial through hole. The shaft is configured such that the push rod 12 passes through the first axial through hole and the second axial through hole to exit the main outlet valve sleeve 1, and is connected to the power mechanism. The power mechanism drives the push rod 12 to reciprocate along the axial direction of the hydraulic control main valve core 5. At the same time, the push rod 12 is clearance-fitted with the first axial through hole and the second axial through hole, so that the high pressure liquid entering from the main inlet P can enter the first pilot mechanism through the inlet of the first pilot mechanism, and then enter the first control cavity 15. The high pressure liquid exiting from the first control cavity 15 enters the second pilot mechanism through the inlet of the second pilot mechanism, thereby realizing the opening or closing of the hydraulic control main valve core 5.

[0047] The pilot valve core is a cone valve, but a small ball 9 and a spring seat 8 can also be used instead of a cone valve. The pilot valve seat includes an upper valve seat 10 and a lower valve seat 6. The pilot valve core is located in the lower valve seat 6, and the pilot spring 7 is also located in the lower valve seat 6.

[0048] Furthermore, at both ends of the hydraulic main valve core 5, a clamping plug 11 and a pilot component are sequentially arranged axially inward. The clamping plug 11 has a polygonal central hole in the axial direction to accommodate the push rod 12, and a radial clearance is left between the polygonal central hole and the push rod 12. Specifically, the pilot component includes an upper valve seat 10 and a lower valve seat 6. The pilot valve core and the pilot spring 7 are both disposed in the lower valve seat 6. The clamping plug 11 has a polygonal central hole in the axial direction, and the polygonal central hole is coaxially arranged with the pilot valve seat, the pilot valve core, and the hydraulic main valve core 5. The push rod 12 passes sequentially through the main outlet valve sleeve 1, the clamping plug 11, and the upper valve sleeve 10. A radial clearance is left between the push rod 12 and the polygonal central hole, so that the high-pressure liquid flowing into the first pilot mechanism or the second pilot mechanism can flow into the first control cavity 15 or the second control cavity 16. Of course, the clamping plug 11, the upper valve seat 10, and the lower valve seat 6 can also be a single mechanical unit.

[0049] In some embodiments, the push rod 12 is connected to a power mechanism capable of outputting linear motion. The power mechanism is a proportional electromagnet, or a linear motor, or a stepper motor or servo motor 14 with a lead screw and nut mechanism 13, or an electric cylinder composed of a motor and a lead screw and nut, or a hydraulic control circuit.

[0050] In other embodiments, the hydraulic main valve core 5 has a first radial hole a and a second radial hole b at both ends, respectively. The first radial hole a and the second radial hole b are connected to the inlet of the first pilot mechanism and the inlet of the second pilot mechanism, respectively. The hydraulic main valve core 5 has a first annular groove and a second annular groove at the positions corresponding to the first radial hole a and the second radial hole b, and the first radial hole a and the first annular groove are connected, and the second radial hole b and the second annular groove are connected. Specifically, the inlet of the first pilot mechanism and the inlet of the second pilot mechanism are opened on the sleeve wall of the pilot valve seat, that is, small holes are opened radially at the end of the lower valve seat 6 near the upper valve seat 10. The first radial hole a is connected to the inlet of the first pilot mechanism, and the second radial hole b is connected to the inlet of the second pilot mechanism. The first radial hole a is connected to the first annular groove, and the second radial hole b is connected to the second annular groove, so that the high-pressure liquid can smoothly enter the first pilot mechanism and the second pilot mechanism.

[0051] Furthermore, the main valve assembly also includes a main outlet valve sleeve 1, a main valve seat 2, and a high-pressure valve sleeve 3; the hydraulically controlled main valve core 5 includes a valve core body, on which a cone 5.1 is provided. One side of the cone 5.1 is a first valve stem 5.2, and the other side is a second valve stem 5.3. The first valve stem 5.2 is disposed inside the main outlet valve sleeve 1, and the end face of the first valve stem 5.2 and the main outlet valve sleeve 1 form a first control cavity 15; the second valve stem 5.3 is disposed inside the high-pressure valve sleeve 3, and the end face of the second valve stem 5.3 and the high-pressure valve sleeve 3 form a second control cavity 16. Specifically, the main outlet valve sleeve 1, the main valve seat 2, and the high-pressure valve sleeve 3 are arranged sequentially from left to right along the axial direction of the hydraulically controlled main valve core 5. The end face of the first valve stem 5.2 of the hydraulically controlled main valve core 5 forms a first control cavity 15 between itself and the main outlet valve sleeve 1, and the end face of the second valve stem 5.3 forms a second control cavity 16 between itself and the high-pressure valve sleeve 3. This allows the high-pressure fluid to flow into the first control cavity 15 and the second control cavity 16 through the first pilot mechanism and the second pilot mechanism, respectively, thus forming a complete hydraulic control circuit. A main spring is provided between the high-pressure valve sleeve 3 and the hydraulically controlled main valve core 5 to prevent interference between the hydraulically controlled main valve core 5 and the high-pressure valve sleeve when the valve moves.

[0052] Furthermore, the main outlet valve sleeve 1 is provided with a first radial hole k1, a second radial hole k2, and a working port A; the high-pressure valve sleeve 3 is provided with a third radial hole k3, a fourth radial hole k4, and a main inlet P; the inner side of the first radial hole k1 is connected to the first control cavity 15, and the outer side of the first radial hole k1 is connected to the outer side of the third radial hole k3 through an oil passage; the inner side of the second radial hole k2 is connected to the first annular groove, and the outer side of the second radial hole k2 is connected to the main inlet P; the inner side of the third radial hole k3 is connected to the second annular groove; the inner side of the fourth radial hole k4 is connected to the second control cavity 16, and the outer side of the fourth radial hole k4 is connected to the low-pressure return oil channel or the oil tank.

[0053] When the proportional control valve described in this embodiment is working:

[0054] Initially, the power mechanism at the left end causes the push rod 12 in the first pilot mechanism to contact the ball 9, and the power mechanism at the right end pulls the push rod in the second pilot structure to the right to a certain distance, so that the push rod in the second pilot structure and the corresponding ball maintain a certain initial distance, which is exactly the stroke size of the hydraulic main valve core 5.

[0055] The push rod 12 at the left end is driven by the power mechanism at the left end. The push rod 12 pushes the ball 9 away from the upper valve seat 10 by a certain distance. High-pressure liquid flows from the main inlet P through the external channel to the second radial hole k2, passes through the first radial hole a, the ball valve port of the ball 9, and the annular radial gap between the push rod 12, the upper valve seat 10, and the clamping plug 11, and reaches the first control cavity 15. When the pressure in the first control cavity 15 rises to the opening pressure, the hydraulic control main valve core 5 moves to the right, and the PA channel of the main valve component is connected to supply liquid to the outside until the ball valve port of the ball 9 closes again. In this way, the opening amount of the PA channel of the hydraulic control main valve core 5 can remain stable. This process is repeated continuously to realize the step opening control of the hydraulic control main valve core 5 until the hydraulic control main valve core 5 reaches the maximum opening amount. At this time, the push rod at the right end is also in contact with the ball at that end. At this time, the push rod 12 at the left end is quickly returned to the initial zero position by the power mechanism at the left end. The above-mentioned proportional opening process can achieve continuous and smooth control of the opening amount, opening speed and flow rate of the hydraulic main valve core 5 by controlling the rightward displacement and speed of the push rod 12.

[0056] Using the same method as the proportional opening process described above, the right-end power mechanism and the push rod at that end are moved to the left. The high-pressure fluid in the first control cavity 15 passes through the first radial hole k1, the external channel, the third radial hole k3, the second radial small hole b, the ball valve port of the right-end small ball, and the annular radial gap formed by the right-end push rod, the right-end pilot valve seat, and the right-end clamping plug, reaching the second control cavity 16. Then, it passes through the radial hole k4 and returns to the oil tank. The hydraulic main valve core 5 moves to the left, and the opening of the PA channel of the main valve component gradually decreases until the ball valve port of the right-end small ball closes again. This process is repeated continuously, achieving a gradual decrease in the opening of the hydraulic main valve core 5 until the opening of the hydraulic main valve core 5 is completely closed. At this point, all operations are stopped. The above proportional closing process, by controlling the leftward displacement and speed of the right-end push rod, achieves continuous and smooth control of the opening, closing speed, and flow rate of the hydraulic main valve core 5 when it closes.

[0057] Example 2:

[0058] In this embodiment, the main valve component is a two-position three-way structure, and the other components are the same as the proportional control valve described above.

[0059] Among them, reference Figure 2 As shown, the main valve assembly is a two-position three-way structure. The main valve assembly also includes a sleeve valve core 18, a check valve 17, and a switching valve 19. The main outlet valve sleeve 1 is provided with a first radial hole k1, a second radial hole k2, a fifth radial hole k5, and a main return port O. The sleeve valve core 18 is fitted onto the first valve stem 5.2, and one end of it is in contact with the annular stepped surface of the main outlet valve sleeve 1. The main valve seat 2 is provided with a radial working port A. The high-pressure valve sleeve 3 is provided with a third radial hole k3, a fourth radial hole k4, and a main inlet port P. The inner side of the first radial hole k1 communicates with the first control cavity 15, and the outer side of the first radial hole k1 communicates with the inlet port of the check valve 17 through an oil passage. The inner side of the second radial hole k2 communicates with the first... The annular groove is connected, and the outer side of the second radial hole k2 is connected to the main inlet P; the inner side of the fifth radial hole k5 is connected to the sleeve valve core 18 through an oil passage, and the outer side of the fifth radial hole k5 is connected to the outlet of the check valve 17 through an oil passage; the inner side of the third radial hole k3 is connected to the second annular groove, and the outer side of the third radial hole k3 is connected to the outlet of the check valve 17 through an oil passage; the inner side of the fourth radial hole k4 is connected to the second control cavity 16, and the outer side of the fourth radial hole k4 is connected to the low-pressure return oil channel or the oil tank; the switching valve 19 is a two-position two-normally open valve, the inlet of the switching valve 19 is connected to the outlet of the check valve 17 through an oil passage, and the outlet of the switching valve 19 is connected to the low-pressure return oil channel or the oil tank.

[0060] When the proportional control valve described in this embodiment is working:

[0061] Initially, the power mechanism at the left end causes the push rod 12 in the first pilot mechanism to contact the ball 9, and the power mechanism at the right end pulls the push rod in the second pilot structure to the right to a certain distance, so that the push rod in the second pilot structure and the corresponding ball maintain a certain initial distance, which is exactly the stroke size of the hydraulic main valve core 5.

[0062] The push rod 12 at the left end is driven by the power mechanism at the left end. The push rod 12 pushes the ball 9 away from the upper valve seat 10 by a certain distance. High-pressure liquid flows from the main inlet P through the external channel to the second radial hole k2, passes through the first radial hole a, the ball valve port of the ball 9, and the annular radial gap between the push rod 12, the upper valve seat 10, and the clamping plug 11, and reaches the first control cavity 15. At this time, the switching valve 19 is in the closed state. When the pressure in the first control cavity 15 rises to the opening pressure, the hydraulic control main valve core 5 moves to the right, and the PA channel of the main valve component is connected to supply liquid to the outside until the ball valve port of the ball 9 closes again. In this way, the opening amount of the PA channel of the hydraulic control main valve core 5 can remain stable. This process is repeated continuously to realize the step opening control of the hydraulic control main valve core 5 until the hydraulic control main valve core 5 reaches the maximum opening amount. At this time, the push rod at the right end is also in contact with the ball at that end. At this time, the push rod 12 at the left end is quickly returned to the initial zero position by the power mechanism at the left end. The above-mentioned proportional opening process can achieve continuous and smooth control of the opening amount, opening speed and flow rate of the hydraulic main valve core 5 by controlling the rightward displacement and speed of the push rod 12.

[0063] Using the same method as described above for the proportional opening process, the right-end push rod is moved to the left by the power mechanism and the push rod at the right end. The high-pressure fluid in the first control cavity 15 will pass through the first radial hole k1, the external channel, the inlet of the one-way valve 17, the third radial hole k3, the second radial small hole b, the ball valve port of the right-end small ball, and the annular radial gap formed by the right-end push rod, the right-end pilot valve seat, and the right-end clamping plug, reaching the second control cavity 16. Then, it will pass through the radial hole k4 and return to the oil tank. The hydraulic control main valve core 5 moves to the left, and the opening of the PA channel of the main valve component gradually decreases until the ball valve port of the right-end small ball closes again. This process is repeated continuously to achieve the gradual decrease of the opening of the hydraulic control main valve core 5 until the opening of the hydraulic control main valve core 5 is closed to zero. At this time, all operations are stopped. High-pressure fluid exits from the outlet of check valve 17 and reaches sleeve valve core 18 through the fifth radial hole k5 and external channel. The above-mentioned proportional closing process can achieve continuous and smooth control of the opening amount, closing speed and flow rate of hydraulic main valve core 5 when it is closed by controlling the displacement and speed of the right end push rod to the left.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0065] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A proportional control valve, characterized in that, include: The main valve assembly includes a hydraulically controlled main valve core (5). The pilot component includes a first pilot mechanism and a second pilot mechanism with the same structure. The first pilot mechanism and the second pilot mechanism are coaxially and oppositely arranged at both ends of the hydraulic main valve core (5). The first pilot mechanism and the second pilot mechanism act on both ends of the hydraulic main valve core (5) through reciprocating linear motion along the axis of the hydraulic main valve core. The first pilot mechanism and the second pilot mechanism each include a pilot valve seat and a pilot valve core. The pilot valve core is coaxially arranged in the pilot valve seat. One end of the pilot valve core is connected to a pilot directional component (7). The other end of the pilot valve core is provided with a first axial through hole at the position corresponding to the central axis of the pilot valve seat. A push rod (12) coaxial with the pilot valve core and capable of reciprocating motion is passed through the first axial through hole. The push rod (12) is clearance-fitted with the first axial through hole. The hydraulic main valve core (5) is also provided with a first control cavity (15) and a second control cavity (16) at both ends. The inlet of the first pilot mechanism is connected to the main inlet (P) of the main valve component. The first control cavity (15) is connected to the inlet of the second pilot mechanism. The second control cavity (16) is connected to the low-pressure return port or the oil tank.

2. The proportional control valve according to claim 1, characterized in that, The hydraulic main valve core (5) has a clamping plug (11) and the pilot component arranged sequentially at both ends along the axial direction. The clamping plug (11) has a polygonal center hole in the axial direction to accommodate the push rod (12). A radial gap is left between the polygonal center hole and the push rod (12).

3. The proportional control valve according to claim 1 or 2, characterized in that, The top rod (12) is connected to a power mechanism that can output linear motion. The power mechanism is a proportional electromagnet, or a linear motor, or a stepper motor or servo motor (14) plus a screw and nut mechanism (13), or an electric cylinder composed of a motor and a screw and nut, or a hydraulic control circuit.

4. The proportional control valve according to claim 2, characterized in that, The hydraulic main valve core (5) is provided with a first radial small hole (a) and a second radial small hole (b) at both ends, and the first radial small hole (a) and the second radial small hole (b) are respectively connected to the liquid inlet of the first pilot mechanism and the liquid inlet of the second pilot mechanism. The hydraulic main valve core (5) is provided with a first annular groove and a second annular groove at the positions corresponding to the first radial small hole (a) and the second radial small hole (b), and the first radial small hole (a) and the first annular groove are connected, and the second radial small hole (b) is connected to the second annular groove.

5. The proportional control valve according to claim 4, characterized in that, The main valve assembly also includes a main outlet valve sleeve (1), a main valve seat (2), and a high-pressure valve sleeve (3). The hydraulic main valve core (5) includes a valve core body, on which a cone (5.1) is provided. One side of the cone (5.1) is a first valve stem (5.2), and the other side is a second valve stem (5.3). The first valve stem (5.2) is disposed in the main outlet valve sleeve (1), and the end face of the first valve stem (5.2) and the main outlet valve sleeve (1) form the first control cavity (15). The second valve stem (5.3) is disposed inside the high-pressure valve sleeve (3), and a second control cavity (16) is formed between the end face of the second valve stem (5.3) and the high-pressure valve sleeve (3).

6. The proportional control valve according to claim 5, characterized in that, The main valve component is a two-position two-way structure, and the main outlet valve sleeve (1) is provided with a first radial hole (k1), a second radial hole (k2) and a working port (A). The high-pressure valve sleeve (3) is provided with a third radial hole (k3), a fourth radial hole (k4) and the main liquid inlet (P); The inner side of the first radial hole (k1) is connected to the first control cavity (15), and the outer side of the first radial hole (k1) is connected to the outer side of the third radial hole (k3) through an oil passage. The inner side of the second radial hole (k2) is connected to the first annular groove, and the outer side of the second radial hole (k2) is connected to the main liquid inlet (P). The inner side of the third radial hole (k3) is connected to the second annular groove; The inner side of the fourth radial hole (k4) is connected to the second control cavity (16), and the outer side of the fourth radial hole (k4) is connected to the low-pressure return oil channel or the oil tank.

7. The proportional control valve according to claim 5, characterized in that, The main valve component is a two-position three-way structure, and the main valve component also includes a sleeve valve core (18), a one-way valve (17), and a switching valve (19). The main outlet valve sleeve (1) is provided with a first radial hole (k1), a second radial hole (k2), a fifth radial hole (k5), and a main return port (O); The sleeve valve core (18) is fitted onto the first valve stem (5.2), and one end of it is in contact with the annular stepped surface of the main outlet valve sleeve (1); The main valve seat (2) is provided with a radial working port (A); The high-pressure valve sleeve (3) is provided with a third radial hole (k3), a fourth radial hole (k4) and a main liquid inlet (P); The inner side of the first radial hole (k1) is connected to the first control cavity (15), and the outer side of the first radial hole (k1) is connected to the inlet of the one-way valve (17) through an oil passage. The inner side of the second radial hole (k2) is connected to the first annular groove, and the outer side of the second radial hole (k2) is connected to the main liquid inlet (P). The inner side of the fifth radial hole (k5) is connected to the sleeve valve core (18) through an oil passage, and the outer side of the fifth radial hole (k5) is connected to the outlet of the one-way valve (17) through an oil passage. The inner side of the third radial hole (k3) is connected to the second annular groove, and the outer side of the third radial hole (k3) is connected to the outlet of the one-way valve (17) through an oil passage; The inner side of the fourth radial hole (k4) is connected to the second control cavity (16), and the outer side of the fourth radial hole (k4) is connected to the low-pressure return oil channel or the oil tank. The switching valve (19) is a two-position two-normally open valve. The inlet of the switching valve (19) is connected to the outlet of the one-way valve (17) through an oil passage. The outlet of the switching valve (19) is connected to the low-pressure return oil passage or the oil tank.

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