Three-stage hydraulic proportional control valve

Abstract

To provide a three-stage electro-hydraulic proportional control valve for improving the control accuracy of the size of a port of a main valve element and achieving continuous and smooth control of the flow rate.SOLUTION: A main valve component comprises a hydraulic control main valve element 12. A pilot component comprises two first pilot mechanisms 1 and two second pilot mechanisms 16, 17. The two second pilot mechanisms 16, 17 are coaxially arranged at two ends of the hydraulic control main valve element 12. A first cavity 18 and a sixth cavity 23 are formed in respective two ends of the second pilot mechanism 16, 17. The first cavity 18 and the sixth cavity 23 are connected with respective liquid outlets of the two first pilot mechanisms 1. A third cavity 20 and a fourth cavity 21 are formed in respective two ends of the hydraulic control main valve element 12. The third cavity 20 is in communication with a liquid outlet of the second pilot mechanism 16, and has a liquid inlet in communication with the main liquid inlet A. The third cavity 20 is further in communication with a liquid inlet of the second pilot mechanism 17.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to the field of electro-hydraulic control technology, and particularly to a three-stage electro-hydraulic proportional control valve.

Background Art

[0002] Currently, each hydraulic cylinder of a coal mine hydraulic holder adopts a large-flow water-based on-off valve for operation control, and the flow rate cannot be continuously and smoothly controlled. As a result, it brings huge mechanical, pressure, and flow rate impacts, not only damaging the holder or the hydraulic system, but also making the position control of the holder hydraulic cylinder inaccurate, affecting the posture of the hydraulic holder and its bonding state with the surrounding rocks, and affecting the smart level of the holder. Therefore, in order to achieve the smart, safe, stable, and high-efficient support and protection of the hydraulic support, it is necessary to reform the conventional on-off amount control technology to achieve continuous and smooth control of the flow rate.

[0003] Proportional control technology is the fundamental approach to solving the above problems. Among them, the proportional control valve is the key to realizing this technology. Therefore, the present invention provides a novel three-stage electro-hydraulic proportional control valve, which can accurately, continuously, and smoothly adjust the size and flow rate of the ports of the proportional control valve, and solve various impact problems caused by the conventional electro-hydraulic on-off valve, the problem of inaccurate positioning of the hydraulic cylinder, and the problem of low control accuracy of the size of the main port of the conventional pilot-type water-based proportional valve.

Summary of the Invention

Problems to be Solved by the Invention

[0004] To solve the above technical problems, the present disclosure provides a three-stage electro-hydraulic proportional control valve that improves the control accuracy of the size of the ports of the main valve body of hydraulic control and realizes continuous and smooth control of the flow rate.

Means for Solving the Problems

[0005] [[ID=3२]] The present disclosure provides a three-stage electro-hydraulic proportional control valve, which A main valve member including a main valve body for hydraulic control, A pilot member comprising a first pilot mechanism and a second pilot mechanism, wherein the first pilot mechanism comprises a first pilot mechanism I and a first pilot mechanism II having the same structure, the second pilot mechanism comprises a second pilot mechanism I and a second pilot mechanism II having the same structure, the first pilot mechanism I and the first pilot mechanism II are connected to the same pressure source, the second pilot mechanism I and the second pilot mechanism II are coaxial with the main valve body of the hydraulic control and installed facing backward at both ends of the main valve body of the hydraulic control, and both of the second pilot mechanisms have a two-position, two-port structure, A first cavity and a sixth cavity are installed at the outer ends of the second pilot mechanism I and the second pilot mechanism II, respectively. The first cavity is connected to the drain port of the first pilot mechanism I, and the sixth cavity is connected to the drain port of the first pilot mechanism II. Reset mechanisms are further installed on the second pilot mechanism I and the second pilot mechanism II. A third cavity and a fourth cavity are installed at both ends of the main valve body of the hydraulic control, respectively. The third cavity communicates with the drain port of the second pilot mechanism I, the fluid inlet of the second pilot mechanism I communicates with the main fluid inlet, the third cavity further communicates with the fluid inlet of the second pilot mechanism II, and the fourth cavity communicates with a low-pressure fluid return port or a tank.

[0006] Selectively, the first pilot mechanism I and the first pilot mechanism II are proportional pressure reducing valves, proportional directional valves, or pressure output circuits composed of elements such as high-speed on / off valves and hydraulic resistors.

[0007] Selectively, the second pilot mechanism I and the second pilot mechanism II act on both ends of the hydraulically controlled main valve body by reciprocating linear motion along the axis of the hydraulically controlled main valve body, and both include a pilot valve seat and a pilot valve body, the pilot valve body being coaxially installed within the pilot valve seat, A pilot elastic member is connected to one end of the pilot valve body, an axial through hole is drilled at the other end of the pilot valve body at a position corresponding to the central axis of the pilot valve seat, a push rod is drilled in the axial through hole coaxial with the pilot valve body and capable of reciprocating motion, the push rod is loosely fitted into the axial through hole, and several radial fluid supply holes are drilled in the pilot valve seat at a position close to the other end of the pilot valve body.

[0008] Selectively, a clamping plug and the pilot member are installed in order at both ends of the main valve body of the hydraulic control, facing inward along the axial direction. The clamping plug has a polygonal central hole drilled along the axial direction to accommodate the push rod, and a radial gap is left between the polygonal central hole and the push rod.

[0009] Selectively, the reset mechanism includes a proportional spring, and the push rod has a boss. The reset mechanism has one end connected to the boss and the other end fixedly connected to the main valve member, and the push rod is moved by the reset mechanism to return to the initial zero position when the pressure of the first pilot mechanism is zero. The second cavity and the fifth cavity are installed in the main valve member at positions corresponding to the reset mechanism of the second pilot mechanism I and the second pilot mechanism II.

[0010] Selectively, the main valve member further includes a main drain valve sleeve, a main valve seat, and a high-pressure valve sleeve, the main drain valve sleeve, the main valve seat, and the high-pressure valve sleeve are connected in sequence along the axial direction of the main valve body of the hydraulic control. The main valve body of the hydraulic control is a conical valve, the valve stem of the main valve body of the hydraulic control has a frustocone, the left end valve stem of the main valve body of the hydraulic control is installed in the axial hole at the right end of the main drain valve sleeve, the third cavity is formed between the left end face of the main valve body of the hydraulic control and the main drain valve sleeve, the right end valve stem of the main valve body of the hydraulic control is installed in the axial hole at the left end of the high-pressure valve sleeve, the fourth cavity is formed between the right end face of the main valve body of the hydraulic control and the high-pressure valve sleeve. Mounting holes are provided axially along the two end faces of the main valve body of the hydraulic control, and these mounting holes are used to mount the second pilot mechanism. A first radial hole and a second radial hole are provided at both ends of the main valve body of the hydraulic control, and the positions of the first radial hole and the second radial hole communicate with the corresponding guide sleeves. A first annular groove and a second annular groove are provided at both ends of the main valve body of the hydraulic control, and the first annular groove and the second annular groove communicate with the first radial hole and the second radial hole, respectively.

[0011] Selectively, the main valve member further includes two end caps, the two end caps respectively installed at opposite ends of the main drain valve sleeve and the high-pressure valve sleeve, the second cavity formed between one end cap and the axial hole of the main drain valve sleeve, the fifth cavity formed between the other end cap and the axial hole of the high-pressure valve sleeve, and the first cavity and the sixth cavity respectively formed between the two push rods and the two end caps, the first cavity and the sixth cavity installed corresponding to the second cavity and the fifth cavity, A seventh radial hole is provided in the end cap closest to the main drain valve sleeve, with one end of the seventh radial hole communicating with the first cavity and the other end communicating with the corresponding output terminal of the first pilot mechanism I. An eighth radial hole is provided in the end cap closest to the high-pressure valve sleeve, with one end of the eighth radial hole communicating with the sixth cavity and the other end communicating with the corresponding output terminal of the first pilot mechanism II.

[0012] Selectively, a first radial hole, a second radial hole, a third radial hole, and a main drain port are installed in the main drain valve sleeve in the axial direction, The high-pressure valve sleeve is provided with the main liquid inlet, the fourth radial hole, the fifth radial hole, and the sixth radial hole in order along the axial direction. The first radial hole has one end communicating with the second cavity and the other end communicating with a low-pressure liquid return port or tank. The second radial hole has one end that communicates with the third cavity and the other end that communicates with the fourth radial hole via an oil passage. The third radial hole has one end that communicates with the first annular groove and the other end that communicates with the main fluid supply port via an oil passage. The fourth radial hole has one end that communicates with the second annular groove, and the other end that communicates with the second radial hole via an oil passage. The fifth radial hole has one end communicating with the fourth cavity and the other end communicating with a low-pressure liquid return port or tank. The sixth radial hole has one end that communicates with the fifth cavity and the other end that communicates with a low-pressure liquid return port or a tank. [Effects of the Invention]

[0013] The technical solutions provided in the embodiments of this application have the following advantages compared to the prior art.

[0014] This embodiment provides a three-stage electro-hydraulic proportional control valve. High-pressure fluid enters the third cavity via the main fluid inlet, the fluid inlet of the second pilot mechanism I, and the fluid outlet of the second pilot mechanism I. The third cavity is further connected to the fluid inlet of the second pilot mechanism II, and the fourth cavity is connected to a low-pressure fluid return port or a tank. As a result, the high-pressure fluid in the third cavity enters the fourth cavity via the second pilot mechanism II and is returned to the tank. In this way, the main valve body of the hydraulic control is turned on or off, and the opening amount, speed, flow rate, and continuous and smooth control are achieved when the main valve body of the hydraulic control is turned on or off. This reduces the mechanical and pressure-flow shock to the hydraulic holder and enables precise control of the hydraulic holder. [Brief explanation of the drawing]

[0015] The drawings herein are incorporated herein and constitute part of this specification, illustrating embodiments conforming to this disclosure and are used together with this specification to interpret the principles of this disclosure.

[0016] To more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the drawings necessary for the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative efforts. [Figure 1] It is a schematic structural diagram of a three-stage electro-hydraulic proportional control valve described in an embodiment of the present disclosure.

Modes for Carrying Out the Invention

[0017] To more clearly understand the above objects, features and advantages of the present disclosure, the solutions of the present disclosure will be further described below. In addition, if there is no contradiction, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0018] In the following description, many specific details will be described in order to fully understand the present disclosure. However, the present disclosure can also be implemented in other ways than those described here. Obviously, the embodiments in this specification are only some embodiments of the present disclosure, not all embodiments.

[0019] As shown in FIG. 1, the embodiment of the present disclosure provides a three-stage electro-hydraulic proportional control valve, which includes a main valve member and a pilot member.

[0020] Among them, the main valve member includes the main valve body 12 of hydraulic control, the pilot member includes the first pilot mechanism 1 and the second pilot mechanism. The first pilot mechanism includes the first pilot mechanism I1.1 and the first pilot mechanism II1.2 with the same structure. The second pilot mechanism includes the second pilot mechanism I16 and the second pilot mechanism II17 with the same structure. The first pilot mechanism I1.1 and the first pilot mechanism II1.2 are connected to the same pressure source. The second pilot mechanism I16 and the second pilot mechanism II17 are coaxial with the main valve body 12 of hydraulic control and are installed opposite to both ends of the main valve body 12 of hydraulic control. Moreover, both of the two second pilot mechanisms have a two-position two-port structure, and the two second pilot mechanisms can perform reciprocating linear motion to act on both ends of the main valve body 12 of hydraulic control. Specifically, two of each of the first pilot mechanism 1 and the second pilot mechanism are installed. The first pilot mechanism I1.1 and the first pilot mechanism II1.2 have the same structure and are connected to the same pressure source, and both are pressure output control methods. The second pilot mechanism I16 and the second pilot mechanism II17 have the same structure and are coaxially installed at both ends of the main valve body 12 of hydraulic control. The second pilot mechanism I16 and the second pilot mechanism II17 both have a two-position two-port structure and move along the axial direction of the main valve body 12 of hydraulic control, and can move the main valve body 12 of hydraulic control.

[0021] Of these, a first cavity 18 and a sixth cavity 23 are installed at the outer ends of the second pilot mechanism I16 and the second pilot mechanism II17, respectively. The first cavity 18 is connected to the drain port of the first pilot mechanism I1.1, and the sixth cavity 23 is connected to the drain port of the first pilot mechanism II1.2. A reset mechanism 5 is further installed on the second pilot mechanism I16 and the second pilot mechanism II17. A third cavity 20 and a fourth cavity 21 are installed at both ends of the main valve body 12 for hydraulic control, respectively. The third cavity 20 communicates with the drain port of the second pilot mechanism I16, the supply port of the second pilot mechanism I16 communicates with the main supply port P, the third cavity 20 further communicates with the supply port of the second pilot mechanism II17, and the fourth cavity 21 communicates with the low-pressure liquid return port or tank. Specifically, the first cavity 18 and the sixth cavity 23 are connected to the second pilot mechanism I16, the second pilot mechanism II17, and the pilot valve. bodyAll are installed coaxially, the first cavity 18 is connected to the drain port of the first pilot mechanism I1.1, and the sixth cavity 23 is connected to the drain port of the first pilot mechanism II1.2, forming a liquid circuit between the first cavity 18 and the sixth cavity 23. A reset mechanism 5 is further installed on the second pilot mechanism I16 and the second pilot mechanism II17, which moves the second pilot mechanism I16 and the second pilot mechanism II17 back to their initial positions, allowing the following operations to be performed. A third cavity 20 and a fourth cavity 21 are further installed on both ends of the main valve body 12 of the hydraulic control, the third cavity 20 is in communication with the drain port of the second pilot mechanism I16, and the second pilot mechanism I16 is in communication with the liquid supply port. The valve body 12 is connected to the main fluid inlet P, and the high-pressure fluid enters the third cavity 20 via the main fluid inlet P, the fluid inlet of the second pilot mechanism I16, and the fluid outlet of the second pilot mechanism I16. The third cavity 20 is further connected to the fluid inlet of the second pilot mechanism II17, and the fourth cavity 21 is connected to the low-pressure fluid return port or tank. As a result, the high-pressure fluid in the third cavity 20 enters the fourth cavity 21 via the second pilot mechanism II17 and is returned to the tank. In this way, the main valve body 12 of the hydraulic control is turned on or off, and the opening amount, speed, flow rate, and continuous and smooth control are achieved when the main valve body 12 of the hydraulic control is turned on or off, reducing the mechanical and pressure flow shocks of the hydraulic holder and achieving precise control of the hydraulic holder.

[0022] Furthermore, the first pilot mechanism I1.1 and the first pilot mechanism II1.2 are proportional pressure reducing valves, or proportional directional valves, or pressure output circuits composed of elements such as high-speed on / off valves and hydraulic resistors. When the first pilot mechanism 1 is not under normal operating control, there is no pressure output.

[0023] In some embodiments, the second pilot mechanism I16 and the second pilot mechanism II 17Each of these components includes a pilot valve seat 7 and a pilot valve body. The pilot valve body is coaxially installed within the pilot valve seat 7, one end of the pilot valve body is connected to a pilot elastic member 10, and the other end of the pilot valve body has an axial through-hole at a position corresponding to the central axis of the pilot valve seat 7. A push rod 3, which is coaxial with the pilot valve body and capable of reciprocating motion, is drilled in the axial through-hole. The push rod 3 is loosely fitted into the axial through-hole, and several radial fluid supply holes are drilled in the pilot valve seat 7 near the other end of the pilot valve body. Specifically, the pilot valve body is installed inside the pilot valve seat 7 and coaxially with the pilot valve seat 7, and a pilot elastic member 10 is connected to one end of the pilot valve body. When the pilot valve body moves, it does not directly contact one end of the pilot valve seat 7 with a large impact force, thus avoiding damage to the pilot valve body and pilot valve seat 7. The pilot elastic member 10 is either a spring or a component that performs a cushioning action. An axial through hole is drilled at the other end of the pilot valve body at a position corresponding to the central axis of the pilot valve seat 7, and the push rod 3 has an axial through hole drilled through it to serve as the main valve body for hydraulic control. 12 It can perform reciprocating motion along the axial direction, and is loosely fitted between the push rod 3 and the axial through hole, allowing the high-pressure liquid entering from the main liquid supply port P to enter the first pilot mechanism 1, thereby entering the third cavity 20 through the gap between the push rod 3 and the axial through hole, and the high-pressure liquid exiting the third cavity 20 to enter the second pilot mechanism II 17 Entering into this cavity, thereby entering the fourth cavity 21, enables the on or off of the hydraulically controlled main valve body 12, and several radial fluid supply holes are opened near the other end of the pilot valve body of the pilot valve seat 7, these fluid supply holes are the second pilot mechanism I16 and the second pilot mechanism II 17 This is the liquid supply port.

[0024] Furthermore, tightening plugs are attached to both ends of the main valve body 12 of the hydraulic control system, facing inward along the axial direction. 6 The pilot member is then installed in order, followed by the tightening plug. 6A polygonal central hole is drilled along the axial direction to accommodate the push rod 3, leaving a radial gap between the polygonal central hole and the push rod 3. Specifically, the pilot member includes a pilot valve seat 7, a guide sleeve 11, a ball 8, and a spring seat 9. The end faces of the main valve body 12 for hydraulic control are arranged inward in order to the tightening plug 6, the pilot valve seat 7, and the guide sleeve 11. These three can also form a mechanical whole. Of these, the pilot valve body is a conical valve, and the ball 8 and spring seat 9 can substitute for a conical valve. The tightening plug 6 has a polygonal central hole drilled along the axial direction, and the polygonal central hole is coaxially installed in the pilot valve seat 7, the pilot valve body, and the main valve body 12 for hydraulic control. A radial gap is left between the push rod 3 and the polygonal central hole, and the high-pressure fluid that enters the second pilot mechanism can enter the third cavity 20 or the fourth cavity 21.

[0025] In some embodiments, the reset mechanism 5 includes a proportional spring, the push rod 3 has a boss, one end of the reset mechanism 5 is connected to the boss and the other end is fixedly connected to the main valve member, the push rod 3 is moved by the reset mechanism 5 to return to the initial zero position when the pressure in the first pilot mechanism 1 is zero, and the second cavity 19 and fifth cavity 22 are installed in the second pilot mechanism I16 and second pilot mechanism II17 of the main valve member at positions corresponding to the reset mechanism 5. Specifically, the reset mechanism 5 may be a proportional spring or any component that has an elastic action to move the push rod 3 and perform a contraction motion, a boss is installed at one end of the push rod 3 away from the third cavity 20, one end of the reset mechanism 5 is connected to the boss and the other end is fixed to the main valve member, and when the pressure in the first pilot mechanism 1 is zero, the reset mechanism 5 moves the push rod 3 to return to the initial zero position and prepares to perform the next operation, the second cavity 19 and fifth cavity 22 are used to house the reset mechanism 5.

[0026] Furthermore, the main valve member further includes a main drain valve sleeve 4, a main valve seat 13, and a high-pressure valve sleeve 15, the main drain valve sleeve 4, the main valve seat 13, and the high-pressure valve sleeve 15 being connected sequentially along the axial direction of the main valve body 12 for hydraulic control, the main valve body 12 for hydraulic control being a conical valve, the valve stem of the main valve body 12 for hydraulic control having a frustocone, the left end valve stem of the main valve body 12 for hydraulic control being installed in the axial hole at the right end of the main drain valve sleeve 4, a third cavity 20 being formed between the left end face of the main valve body 12 for hydraulic control and the main drain valve sleeve 4, the right end valve stem of the main valve body 12 for hydraulic control being installed in the axial hole at the left end of the high-pressure valve sleeve 15, a fourth cavity 21 being formed between the right end face of the main valve body 12 for hydraulic control and the high-pressure valve sleeve 15. Specifically, the main drain valve sleeve 4, the main valve seat 13, and the high-pressure valve sleeve 15 are arranged sequentially from left to right along the axial direction of the main valve body 12 of the hydraulic control. A third cavity 20 is formed between the left end face of the main valve body 12 of the hydraulic control and the main drain valve sleeve 4, and a fourth cavity 21 is formed between the right end face of the main valve body 12 of the hydraulic control and the high-pressure valve sleeve 15. High-pressure fluid enters the third cavity 20 and the fourth cavity 21, respectively, via a second pilot mechanism, thereby realizing the formation of a complete hydraulic control circuit. A main spring 14 is installed between the high-pressure valve sleeve 15 and the main valve body 12 of the hydraulic control to prevent interference between the high-pressure valve sleeve 15 and the main valve body 12 when the main valve body 12 of the hydraulic control moves.

[0027] Mounting holes are provided axially along the two end faces of the main valve body 12 for hydraulic control, and these mounting holes are used to mount the second pilot mechanism. A first radial hole a and a second radial hole b are provided at both ends of the main valve body 12 for hydraulic control, and the positions of the first radial hole a and the second radial hole b communicate with the corresponding guide sleeve 11. A first annular groove and a second annular groove are provided at both ends of the main valve body 12 for hydraulic control, and the first annular groove and the second annular groove communicate with the first radial hole a and the second radial hole b, respectively. Specifically, the two second pilot mechanisms are mounted in mounting holes located at both ends of the main valve body 12 of the hydraulic control, and further, a first radial hole a and a second radial hole b are provided at both ends of the main valve body 12 of the hydraulic control, the first radial hole a communicates with the guide sleeve 11 of the second pilot mechanism I16, and the second radial hole b communicates with the guide sleeve 11 of the second pilot mechanism II17, and further, a first ring is provided at both ends of the main valve body 12 of the hydraulic control A groove and a second annular groove are provided, with the first annular groove communicating with the first radial hole a, and the second annular groove communicating with the second radial hole b. As a result, the high-pressure liquid enters the second pilot mechanism I16 via the main liquid inlet P, the first annular groove and the first radial hole, and thereby enters the third cavity 20. The high-pressure liquid in the third cavity 20 enters the second pilot mechanism II17 via the second annular groove and the second radial hole b, and thereby enters the fourth cavity 21.

[0028] Furthermore, the main valve member further includes two end caps 2, which are installed at opposite ends of the main drain valve sleeve 4 and the high-pressure valve sleeve 15, respectively. A second cavity 19 is formed between one end cap 2 and the axial hole of the main drain valve sleeve 4, a fifth cavity 22 is formed between the other end cap 2 and the axial hole of the high-pressure valve sleeve 15, and a first cavity 18 and a sixth cavity 23 are formed between the two push rods 3 and the two end caps 2, respectively. The first cavity 18 and the sixth cavity 23 are installed corresponding to the second cavity 19 and the fifth cavity 22, respectively. Specifically, one end cap 2 is screwed or fixed to the main drain valve sleeve 4, forming a second cavity 19 between it and the axial hole of the main drain valve sleeve 4 to house the reset mechanism 5; another end cap 2 is screwed or fixed to the high-pressure valve sleeve 15, forming a fifth cavity 22 between it and the axial hole of the high-pressure valve sleeve 15 to house the reset mechanism 5; a first cavity 18 and a sixth cavity 23 are formed between the two push rods 3 and the two end caps 2, respectively, and the first cavity 18 and the sixth cavity 23 control and move the corresponding push rods 3 by the pressure within their own cavities.

[0029] Of these, a seventh radial hole k7 is made in the end cap 2 closest to the main drain valve sleeve 4, with one end of the seventh radial hole k7 communicating with the first cavity 18 and the other end communicating with the output terminal of the corresponding first pilot mechanism I1.1, and an eighth radial hole k8 is made in the end cap 2 closest to the high-pressure valve sleeve 15, with one end of the eighth radial hole k8 communicating with the sixth cavity 23 and the other end communicating with the output terminal of the corresponding first pilot mechanism II1.2. Specifically, the first pilot mechanism I1.1 and the first pilot mechanism II1.2 are connected to the same pressure source, and by installing the seventh radial hole k7 and the eighth radial hole k8, the gas source can be transported to the first cavity 18 and the sixth cavity 23, respectively, through the seventh radial hole k7 and the eighth radial hole k8. This adjusts the pressure in the first cavity 18 and the sixth cavity 23, thereby acting on the corresponding push rod 3, which moves the push rod 3 along the axial direction of the hydraulically controlled main valve body 12, thereby moving the hydraulically controlled main valve body 12 and enabling the on or off of the hydraulically controlled main valve body 12. In other words, by adjusting the pressure in the first cavity 18 and the sixth cavity 23, the movement speed of the push rod 3 can be controlled, thereby enabling continuous and smooth control of the opening amount, speed, and flow rate when the hydraulically controlled main valve body 12 is turned on or off.

[0030] Furthermore, the main drain valve sleeve 4 is sequentially equipped with a first radial hole k1, a second radial hole k2, a third radial hole k3, and a main drain port A along the axial direction, and the high-pressure valve sleeve 15 is sequentially equipped with a main fluid supply port P, a fourth radial hole k4, a fifth radial hole k5, and a sixth radial hole k6 along the axial direction, with one end of the first radial hole k1 communicating with the second cavity 19 and the other end communicating with the low-pressure fluid return port or oil tank, and one end of the second radial hole k2 communicating with the third containment chamber 20 and the other end The fourth radial hole k4 is connected via an oil passage, the third radial hole k3 has one end connected to the first annular groove and the other end connected to the main liquid supply port P via an oil passage, the fourth radial hole k4 has one end connected to the second annular groove and the other end connected to the second radial hole k2 via an oil passage, the fifth radial hole k5 has one end connected to the fourth cavity 21 and the other end connected to the low-pressure liquid return port or tank, and the sixth radial hole k6 has one end connected to the fifth cavity 22 and the other end connected to the low-pressure liquid return port or tank.

[0031] The three-stage electro-hydraulic proportional control valve described in this embodiment operates as follows:

[0032] Initially, the first pilot mechanism 1 is not operated, the pressure in both the first cavity 18 and the sixth cavity 23 is zero, the left push rod 3 contacts the ball 8 at the corresponding position, but the ball port where this ball 8 is located is closed, the right push rod disengages from the ball at the right end, and the distance of disengagement is the stroke of the hydraulically controlled main valve body 12, which is in a closed state, i.e., the PA passage is closed.

[0033] By operating and controlling the first pilot mechanism I1.1, the output pressure is controlled to gradually increase. At this time, the pressure in the first cavity 18 gradually increases, the left end push rod 3 gradually moves to the right, the push rod 3 pushes the ball 8 a certain distance from the pilot valve seat 7, the high-pressure fluid reaches the third radial hole k3 from the main fluid inlet P through the external passage, and reaches the third cavity 20 through the first radial small hole a, the sub-ball of the ball 8, the annular radial gap composed of the push rod 3, the pilot valve seat 7 and the tightening plug 6. When the pressure in the third cavity 20 rises to the ON pressure, the hydraulically controlled main valve body 12 moves to the right, and the main valve member PA passage remains open to supply fluid to the outside until the sub-ball of the ball 8 re-closes. In this way, the opening amount of the PA passage of the hydraulically controlled main valve body 12 can be stably maintained. By repeating this process, the stepping opening of the hydraulically controlled main valve body 12 can be controlled until the hydraulically controlled main valve body 12 reaches its maximum opening. At this time, the right end push rod contacts the right end ball, quickly adjusting and controlling the first pilot mechanism I1.1 to reduce the pressure in the first cavity 18 to zero, and the left end push rod 3 is moved by the reset mechanism 5 to return to its initial zero position. The above proportional activation process controls the pressure in the first cavity 18, that is, controls the displacement and speed of the push rod 3 to the right, thereby enabling continuous and smooth control of the activation opening amount, activation speed, and flow rate of the hydraulically controlled main valve body 12.

[0034] The same method as the proportional activation process described above is employed for the first pilot mechanism II1.2 to move the right end push rod to the left, and the liquid in the third cavity 20 passes through the second radial hole k2, the external passage, the fourth radial hole k4, the second radial small hole b, the sub-ball of the right end ball, and the annular radial gap formed by the right end push rod, the right end pilot valve seat and the right end tightening plug, reaches the fourth cavity 21, and then returns to the tank via the fifth radial hole k5, causing the hydraulically controlled main valve body 12 to move to the left and the opening amount of the main valve member PA passage to gradually decrease until the ball port of the right end ball is re-closed. This process is repeated, and the opening amount of the hydraulically controlled main valve body 12 can be gradually reduced until the opening amount of the hydraulically controlled main valve body 12 is closed to zero. At this time, the left end push rod 3 comes into contact with the left end ball 8. At this time, the first pilot mechanism II1.2 is adjusted and controlled to reduce the pressure in the first cavity 18 to zero, and the right end push rod is moved by the right end reset mechanism to return to its initial zero position. The above proportional closing process controls the leftward displacement and speed of the right end push rod, thereby enabling continuous and smooth control of the opening amount, closing speed, and flow rate when the hydraulically controlled main valve body 12 closes.

[0035] In this specification, relational terms such as "first" and "second" are used solely to distinguish one entity or operation from another, and do not require or suggest any actual relationship or order between these entities or operations. Furthermore, the terms "include," "incorporate," or any other variation thereof are intended to include non-exclusive inclusion, thereby meaning that a process, method, article, or apparatus containing a set of elements includes not only those elements but also other elements not explicitly listed, or elements specific to such a process, method, article, or apparatus. Unless further restrictions are imposed, an element limited by the phrase "includes one..." does not preclude the existence of other identical elements beyond the process, method, article, or apparatus containing the said element.

[0036] The above descriptions represent only specific embodiments of the Disclosure, and those skilled in the art can understand or implement the Disclosure. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the Disclosure. Accordingly, the Disclosure is not limited to these embodiments described herein, but rather conforms to the broadest scope that is consistent with the principles and novel features disclosed herein. [Explanation of Symbols]

[0037] 1. First pilot mechanism, 1.1, First pilot mechanism I, 1.2, First pilot mechanism II, 2. End cap, 3. Push rod, 4. Main drain valve sleeve, 5. Reset mechanism, 6. Tightening plug, 7. Pilot valve seat, 8. Ball, 9. Spring constellation, 10. Pilot spring, 11. Guide sleeve, 12. Main valve body for hydraulic control, 13, main valve seat, 14. Main spring, 15. High-pressure valve sleeve, 16. Second pilot mechanism I, 17. Second pilot mechanism II, 18, First cavity, 19. Second cavity, 20, Third cavity, 21. Fourth cavity, 22, 5th cavity, 23. 6th cavity, a, first radial hole; b, second radial hole; k1, first radial hole; k2, second radial hole; k3, third radial hole, k4, fourth radial hole k5, 5th radial direction hole k6, 6th radial hole A. Main drain outlet P, Main liquid supply port.

Claims

1. A three-stage hydraulic proportional control valve mainly consisting of a first pilot mechanism stage, a second pilot mechanism stage, and a main valve body stage for hydraulic control, A main valve member including a hydraulically controlled main valve body (12), A pilot member comprising a first pilot mechanism (1) and a second pilot mechanism, wherein the first pilot mechanism comprises a first pilot mechanism I (1.1) and a first pilot mechanism II (1.2) having the same structure, the second pilot mechanism comprises a second pilot mechanism I (16) and a second pilot mechanism II (17) having the same structure, the first pilot mechanism I (1.1) and the first pilot mechanism II (1.2) are connected to the same pressure source, the second pilot mechanism I (16) and the second pilot mechanism II (17) are coaxial with the main valve body (12) of the hydraulic control and are installed facing backward at both ends of the main valve body (12) of the hydraulic control, and both of the second pilot mechanisms have a two-position, two-port structure. A first cavity (18) and a sixth cavity (23) are installed at the outer ends of the second pilot mechanism I (16) and the second pilot mechanism II (17), respectively, the first cavity (18) is connected to the drain port of the first pilot mechanism I (1.1), and the sixth cavity (23) is connected to the drain port of the first pilot mechanism II (1.2). Reset mechanisms (5) are further installed on the second pilot mechanism I (16) and the second pilot mechanism II (17), and third cavities are installed at both ends of the main valve body (12) for hydraulic control. Cavities (20) and a fourth cavity (21) are installed, the third cavity (20) is in communication with the drain port of the second pilot mechanism I (16), the liquid inlet of the second pilot mechanism I (16) is in communication with the main liquid inlet (P), the third cavity (20) is further in communication with the liquid inlet of the second pilot mechanism II (17), the fourth cavity (21) is in communication with the low-pressure liquid return port or tank, and the third cavity (20) is in communication with the fourth cavity (21) via the second pilot mechanism II (17), A three-stage hydraulic proportional control valve characterized in that the operation of the first pilot mechanism I (1.1) acts on the corresponding push rod (3), which in turn operates the second pilot mechanism I (16), and the operation of the first pilot mechanism II (1.2) acts on the corresponding push rod (3), which in turn operates the second pilot mechanism II (17), thereby opening and closing the main valve body (12).

2. The three-stage hydraulic proportional control valve according to claim 1, characterized in that the first pilot mechanism I (1.1) and the first pilot mechanism II (1.2) are proportional pressure reducing valves, or proportional directional valves, or pressure output circuits composed of elements such as high-speed on / off valves and hydraulic resistors.

3. The second pilot mechanism I (16) and the second pilot mechanism II (17) act on both ends of the hydraulically controlled main valve body (12) by reciprocating linear motion along the axis of the hydraulically controlled main valve body, and both the second pilot mechanism I (16) and the second pilot mechanism II (17) include a pilot valve seat (7) and a pilot valve body, and the pilot valve body is installed coaxially within the pilot valve seat (7). A three-stage hydraulic proportional control valve according to claim 1, characterized in that a pilot elastic member (10) is connected to one end of the pilot valve body, an axial through hole is drilled at the other end of the pilot valve body at a position corresponding to the central axis of the pilot valve seat (7), a push rod (3) is drilled in the axial through hole coaxial with the pilot valve body and capable of reciprocating motion, the push rod (3) is loosely fitted into the axial through hole, and several radial fluid supply holes are drilled at a position on the pilot valve seat (7) close to the other end of the pilot valve body.

4. The three-stage hydraulic proportional control valve according to claim 3, characterized in that a tightening plug (6) and the pilot member are sequentially installed at both ends of the main valve body (12) of the hydraulic control in an inward direction along the axial direction, the tightening plug (6) has a polygonal central hole drilled along the axial direction to accommodate the push rod (3), and a radial gap is left between the polygonal central hole and the push rod (3).

5. The reset mechanism (5) includes a proportional spring, and the push rod (3) has a boss. The reset mechanism (5) has one end connected to the boss and the other end fixedly connected to the main valve member, and the push rod (3) is moved by the reset mechanism (5) to return to the initial zero position when the pressure of the first pilot mechanism (1) is zero. The three-stage hydraulic proportional control valve according to claim 3, characterized in that a second cavity (19) and a fifth cavity (22) are installed in the main valve member at positions corresponding to the reset mechanisms of the second pilot mechanism I (16) and the second pilot mechanism II (17).

6. The main valve member further includes a main drain valve sleeve (4), a main valve seat (13), and a high-pressure valve sleeve (15), the main drain valve sleeve (4), the main valve seat (13), and the high-pressure valve sleeve (15) are connected in order along the axial direction of the main valve body (12) of the hydraulic control. The main valve body (12) of the hydraulic control is a conical valve, the valve stem of the main valve body (12) of the hydraulic control has a frustocone, the left end valve stem of the main valve body (12) of the hydraulic control is installed in the axial hole at the right end of the main drain valve sleeve (4), the third cavity (20) is formed between the left end face of the main valve body (12) of the hydraulic control and the main drain valve sleeve (4), the right end valve stem of the main valve body (12) of the hydraulic control is installed in the axial hole at the left end of the high-pressure valve sleeve (15), the fourth cavity (21) is formed between the right end face of the main valve body (12) of the hydraulic control and the high-pressure valve sleeve (15), The three-stage hydraulic proportional control valve according to claim 5, characterized in that mounting holes are provided axially along the two end faces of the main valve body (12) of the hydraulic control, the mounting holes are used for mounting the second pilot mechanism, and a first radial hole (a) and a second radial hole (b) are provided at both ends of the main valve body (12) of the hydraulic control, the positions of the first radial hole (a) and the second radial hole (b) are in communication with the corresponding guide sleeve (11), and a first annular groove and a second annular groove are provided at both ends of the main valve body (12) of the hydraulic control, the first annular groove and the second annular groove are in communication with the first radial hole (a) and the second radial hole (b), respectively.

7. The main valve member further includes two end caps (2), the two end caps (2) are installed at opposite ends of the main drain valve sleeve (4) and the high-pressure valve sleeve (15), the second cavity (19) is formed between one end cap (2) and the axial hole of the main drain valve sleeve (4), the fifth cavity (22) is formed between the other end cap (2) and the axial hole of the high-pressure valve sleeve (15), and the first cavity (18) and the sixth cavity (23) are formed between the two push rods (3) and the two end caps (2), the first cavity (18) and the sixth cavity (23) are installed corresponding to the second cavity (19) and the fifth cavity (22), respectively. A three-stage hydraulic proportional control valve according to claim 6, characterized in that a seventh radial hole (k7) is provided in the end cap (2) near the main drain valve sleeve (4), one end of which communicates with the first cavity (18) and the other end of which communicates with the output terminal of the corresponding first pilot mechanism I (1.1), and an eighth radial hole (k8) is provided in the end cap (2) near the high-pressure valve sleeve (15), one end of which communicates with the sixth cavity (23) and the other end of which communicates with the output terminal of the corresponding first pilot mechanism II (1.2).

8. The main drain valve sleeve (4) is provided with a first radial hole (k1), a second radial hole (k2), a third radial hole (k3), and a main drain port (A) in order along the axial direction. The high-pressure valve sleeve (15) is provided with the main liquid inlet (P), the fourth radial hole (k4), the fifth radial hole (k5), and the sixth radial hole (k6) in order along the axial direction. The first radial hole (k1) has one end communicating with the second cavity (19) and the other end communicating with a low-pressure liquid return port or tank. The second radial hole (k2) has one end communicating with the third cavity (20) and the other end communicating with the fourth radial hole (k4) via an oil passage. The third radial hole (k3) has one end that communicates with the first annular groove and the other end that communicates with the main fluid supply port (P) via an oil passage. The fourth radial hole (k4) has one end communicating with the second annular groove and the other end communicating with the second radial hole (k2) via an oil passage. The fifth radial hole (k5) has one end communicating with the fourth cavity (21) and the other end communicating with a low-pressure liquid return port or tank. The three-stage hydraulic proportional control valve according to claim 6, characterized in that one end of the sixth radial hole (k6) communicates with the fifth cavity (22) and the other end communicates with a low-pressure liquid return port or a tank.

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