Three-stage electro-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 all adopts a large-flow water-based on-off valve for operation control. Since the flow rate cannot be continuously and smoothly controlled, it brings huge mechanical, pressure, and flow rate impacts, not only destroying 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 realize 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] In order 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 port of the main valve body for hydraulic control and realizes continuous and smooth control of the flow rate.

Means for Solving the Problems

[0005] 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 including a first pilot mechanism and a second pilot mechanism, wherein the first pilot mechanism includes a first pilot mechanism I and a first pilot mechanism II having the same structure, and the second pilot mechanism includes 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 are installed back-to-back at both ends of the main valve body of the hydraulic control. And both of the two second pilot mechanisms are of a two-position two-port structure, A first cavity and a sixth cavity are respectively installed at the outer ends of the second pilot mechanism I and the second pilot mechanism II. 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. A reset mechanism is further installed in the second pilot mechanism I and the second pilot mechanism II. A third cavity and a fourth cavity are respectively installed at both ends of the main valve body of the hydraulic control. The third cavity communicates with the drain port of the second pilot mechanism I. The supply port of the second pilot mechanism I communicates with the main supply port. The third cavity further communicates with the supply port of the second pilot mechanism II. The fourth cavity communicates with a low-pressure liquid return port or a tank.

[0006] Optionally, the first pilot mechanism I and the first pilot mechanism II are proportional pressure reducing valves, or proportional direction valves, or a pressure output circuit composed of elements such as high-speed on-off valves and hydraulic resistors.

[0007] Optionally, the second pilot mechanism I and the second pilot mechanism II act on both ends of the main valve body of the hydraulic control by reciprocating linear motion along the axis of the main valve body of the hydraulic control. Both include a pilot valve seat and a pilot valve body. The pilot valve body is coaxially installed in the pilot valve seat. A pilot elastic member is connected to one end of the pilot valve body, an axial through-hole is formed at a position corresponding to the central axis of the pilot valve seat at the other end of the pilot valve body, a push rod coaxially arranged with the pilot valve body and capable of reciprocating movement is formed in the axial through-hole, the push rod is loosely fitted in the axial through-hole, and several radial liquid supply holes are formed at a position of the pilot valve seat close to the other end of the pilot valve body.

[0008] Optionally, an inward tightening plug and the pilot member are sequentially installed along the axial direction at both ends of the main valve body of the hydraulic control, the tightening plug is formed with a polygonal central hole 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] Optionally, the reset mechanism includes a proportional spring, and the push rod has a boss. One end of the reset mechanism is connected to the boss, the other end is fixedly connected to the main valve member, and when the pressure of the first pilot mechanism is zero, the push rod is moved by the reset mechanism to return to the initial zero position. A second cavity and a fifth cavity are installed at positions corresponding to the reset mechanisms of the second pilot mechanism I and the second pilot mechanism II of the main valve member.

[0010] Optionally, the main valve member further includes a main drain valve sleeve, a main valve seat and a high-pressure valve sleeve, and the main drain valve sleeve, the main valve seat and the high-pressure valve sleeve are sequentially connected 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, there is a truncated cone on the valve rod of the main valve body of the hydraulic control, the left end valve rod 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, a 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 rod 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, and a 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 axially provided on two end faces of the main valve body of the hydraulic control. The mounting holes are used for mounting the second pilot mechanism, and a first radial small hole and a second radial small hole are respectively provided at both ends of the main valve body of the hydraulic control. The positions of the first radial small hole and the second radial small hole respectively communicate with corresponding guide sleeves. A first annular groove and a second annular groove are respectively provided at both ends of the main valve body of the hydraulic control. The first annular groove and the second annular groove respectively communicate with the first radial small hole and the second radial small hole.

[0011] Optionally, the main valve member further includes two end caps. The two end caps are respectively provided at both ends facing away from the main drain valve sleeve and the high-pressure valve sleeve. The second cavity is formed between one of the end caps and the axial hole of the main drain valve sleeve, and the fifth cavity is formed between the other end cap and the axial hole of the high-pressure valve sleeve. The first cavity and the sixth cavity are respectively formed between the two push rods and the two end caps. The first cavity and the sixth cavity are respectively installed corresponding to the second cavity and the fifth cavity. A seventh radial hole is opened in the end cap close to the main drain valve sleeve. One end of the seventh radial hole communicates with the first cavity, and the other end communicates with the output end of the corresponding first pilot mechanism I. An eighth radial hole is opened in the end cap close to the high-pressure valve sleeve. One end of the eighth radial hole communicates with the sixth cavity, and the other end communicates with the output end of the corresponding first pilot mechanism II.

[0012] Optionally, a first radial hole, a second radial hole, a third radial hole and a main drain port are sequentially provided along the axial direction of the main drain valve sleeve. The main liquid supply port, a fourth radial hole, a fifth radial hole and a sixth radial hole are sequentially provided along the axial direction of the high-pressure valve sleeve. One end of the first radial hole communicates with the second cavity, and the other end communicates with a low-pressure liquid reflux port or a tank. One end of the second radial hole communicates with the third cavity, and the other end communicates with the fourth radial hole via an oil passage. One end of the third radial hole communicates with the first annular groove, and the other end communicates with the main liquid supply port via an oil passage. One end of the fourth radial hole communicates with the second annular groove, and the other end communicates with the second radial hole via an oil passage. One end of the fifth radial hole communicates with the fourth cavity, and the other end communicates with a low-pressure liquid return port or a tank. One end of the sixth radial hole communicates with the fifth cavity, and the other end communicates with a low-pressure liquid return port or a tank.

Advantages of the Invention

[0013] The technical solution provided by the embodiments of the present application has the following advantages compared with the prior art.

[0014] This embodiment provides a three-stage electro-hydraulic proportional control valve. High-pressure liquid enters the third cavity through the main liquid supply port, the liquid supply port of the second pilot mechanism I, and the drain port of the second pilot mechanism I. The third cavity further communicates with the liquid supply port of the second pilot mechanism II. The fourth cavity communicates with a low-pressure liquid return port or a tank. Thereby, the high-pressure liquid in the third cavity enters the fourth cavity through the second pilot mechanism II and returns to the tank, thus realizing the on or off of the main valve body of the hydraulic control, and realizing the opening amount, speed, flow rate magnitude and continuous and smooth control when the main valve body of the hydraulic control is on or off, reducing the mechanical and pressure flow impact of the hydraulic holder, and realizing the accurate control of the hydraulic holder.

Brief Description of the Drawings

[0015] The drawings here are incorporated into this specification and form a part of this specification, showing embodiments that conform to the present disclosure, and are used to interpret the principles of the present disclosure together with this specification.

[0016] To more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the drawings necessary for describing 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

Embodiments 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, when there is no conflict, the embodiments of the present disclosure and the features in the embodiments can be combined with each other.

[0018] In the following description, many specific details will be described 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 embodiments of the present disclosure provide 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 for 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 for hydraulic control and are installed opposite to both ends of the main valve body 12 for hydraulic control. And 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 for 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 for 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 for hydraulic control, and can move the main valve body 12 for hydraulic control to move.

[0021] Among them, a first cavity 18 and a sixth cavity 23 are respectively installed at the outer ends of the second pilot mechanism I16 and the second pilot mechanism II17. 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 respectively installed at both ends of the main valve body 12 of the hydraulic control. The third cavity 20 communicates with the drain port of the second pilot mechanism I16. The liquid supply port of the second pilot mechanism I16 communicates with the main liquid supply port P. The third cavity 20 further communicates with the liquid supply port of the second pilot mechanism II17. The fourth cavity 21 communicates with the low-pressure liquid return port or the tank.Specifically, the first cavity 18 and the sixth cavity 23 are all coaxially installed on the second pilot mechanism I16, the second pilot mechanism II17, and the pilot valve body 12. 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. The first cavity 18 and the sixth cavity 23 form a liquid circuit. A reset mechanism 5 is further installed on the second pilot mechanism I16 and the second pilot mechanism II17. The reset mechanism 5 moves the second pilot mechanism I16 and the second pilot mechanism II17 to return to their initial positions, enabling the next operation. A third cavity 20 and a fourth cavity 21 are respectively installed at both ends of the main valve body 12 of the hydraulic control. 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. High-pressure liquid enters the third cavity 20 through the main supply port P, the supply port of the second pilot mechanism I16, and the drain port of the second pilot mechanism I16. The third cavity 20 further communicates with the supply port of the second pilot mechanism II17. The fourth cavity 21 communicates with the low-pressure liquid return port or the tank. Thereby, the high-pressure liquid in the third cavity 20 enters the fourth cavity 21 through the second pilot mechanism II17 and returns to the tank, thus realizing the on or off of the main valve body 12 of the hydraulic control, realizing the opening amount, speed, flow rate magnitude, and continuous and smooth control when the main valve body 12 of the hydraulic control is on or off, reducing the mechanical and pressure-flow impact of the hydraulic holder, and realizing the precise control of the hydraulic holder.

[0022] Furthermore, the first pilot mechanism I1.1 and the first pilot mechanism II1.2 are a proportional pressure reducing valve, or a proportional direction valve, or a pressure output circuit composed of elements such as a high-speed on-off valve and a hydraulic resistance. When the first pilot mechanism 1 is not normally operationally controlled, there is no pressure output.

[0023] In some embodiments, both the second pilot mechanism I16 and the second pilot mechanism II2.2 include 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 the pilot elastic member 10. The other end of the pilot valve body has an axial through-hole opened at a position corresponding to the central axis of the pilot valve seat 7. A push rod 3 that is coaxial with the pilot valve body and can reciprocate is drilled within the axial through-hole. The push rod 3 is loosely fitted within the axial through-hole. Several radial liquid supply holes are opened at a position close to the other end of the pilot valve body of the pilot valve seat 7. Specifically, the pilot valve body is installed inside the pilot valve seat 7 and is coaxially installed with the pilot valve seat 7. The 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, avoiding damage to the pilot valve body and the pilot valve seat 7. The pilot elastic member 10 can be a spring, or any component that performs a buffering function can be the pilot elastic member 10. An axial through-hole is opened at a position corresponding to the central axis of the pilot valve seat 7 at the other end of the pilot valve body. The push rod 3 can reciprocate along the axial direction of the main valve body 5 of the hydraulic control by drilling through the axial through-hole. Also, the push rod 3 is loosely fitted between the push rod 3 and the axial through-hole. The high-pressure liquid entering from the main liquid supply port P can enter the first pilot mechanism 1, and thereby enter the third cavity 20 through the gap between the push rod 3 and the axial through-hole. The high-pressure liquid exiting from the third cavity 20 enters the second pilot mechanism II2.2, and thereby enters the fourth cavity 21, realizing the on or off of the main valve body 12 of the hydraulic control. Several radial liquid supply holes are opened at a position close to the other end of the pilot valve body of the pilot valve seat 7. This liquid supply hole is the liquid supply hole of the second pilot mechanism I16 and the second pilot mechanism II2.2.

[0024] Furthermore, a tightening plug 11 and a pilot member are sequentially installed inward along the axial direction at both ends of the main valve body 12 for hydraulic control. The tightening plug 11 is provided with a polygonal central hole 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. 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 sequentially arranged inward as the tightening plug 6, the pilot valve seat 7, and the guide sleeve 11. These three can also be regarded as a mechanical whole. Among them, the pilot valve body is a conical valve, and the ball 8 and the spring seat 9 can replace the conical valve. The tightening plug 6 is provided with a polygonal central hole along the axial direction, and the polygonal central hole is coaxially installed on 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 liquid entering 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. When the pressure of the first pilot mechanism 1 is zero, the push rod 3 is moved by the reset mechanism 5 to return to the initial zero position. The second cavity 19 and the fifth cavity 22 are installed at positions corresponding to the reset mechanism 5 of the second pilot mechanism I16 and the second pilot mechanism II17 of the main valve member. Specifically, the reset mechanism 5 may be a proportional spring, or any component having an elastic effect to move the push rod 3 to perform a contraction movement. 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. 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 for the next operation. The second cavity 19 and the fifth cavity 22 are used to accommodate 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 are sequentially connected 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. There is a truncated cone on the valve rod of the main valve body 12 of the hydraulic control. The left-end valve rod 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. 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. The right-end valve rod 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. 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. Specifically, the main drain valve sleeve 4, the main valve seat 13, and the high-pressure valve sleeve 15 are arranged in sequence 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. 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. The high-pressure liquid enters the third cavity 20 and the fourth cavity 21 respectively through the second pilot mechanism, 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 from occurring between the high-pressure valve sleeve 15 and the main valve body 12 of the hydraulic control when the main valve body 12 of the hydraulic control moves.

[0027] Among them, mounting holes are axially provided on two end faces of the main valve body 12 for hydraulic control. The mounting holes are used for mounting the second pilot mechanism, and a first radial small hole a and a second radial small hole b are respectively provided at both ends of the main valve body 12 for hydraulic control. The positions of the first radial small hole a and the second radial small hole b communicate with the corresponding guide sleeves 11 respectively. A first annular groove and a second annular groove are respectively provided at both ends of the main valve body 12 for hydraulic control. The first annular groove and the second annular groove communicate with the first radial small hole a and the second radial small hole b respectively. Specifically, the two second pilot mechanisms are respectively mounted in the mounting holes provided at both ends of the main valve body 12 for hydraulic control, and a first radial small hole a and a second radial small hole b are further respectively provided at both ends of the main valve body 12 for hydraulic control. The first radial small hole a communicates with the guide sleeve 11 of the second pilot mechanism I16, the second radial small hole b communicates with the guide sleeve 11 of the second pilot mechanism II17, and a first annular groove and a second annular groove are further respectively provided at both ends of the main valve body 12 for hydraulic control. The first annular groove communicates with the first radial small hole a, and the second annular groove communicates with the second radial small hole b. Thereby, the high-pressure liquid enters the second pilot mechanism I16 through the main liquid supply port P, the first annular groove and the first radial small hole, and thereby can enter the third cavity 20. The high-pressure liquid in the third cavity 20 enters the second pilot mechanism II17 through the second annular groove and the second radial small hole b, and thereby enters the fourth cavity 21.

[0028] Furthermore, the main valve member further includes two end caps 2, and the two end caps 2 are respectively installed at both ends facing away from the main drain valve sleeve 4 and the high-pressure valve sleeve 15. A second cavity 19 is formed between one end cap 2 and the axial hole of the main drain valve sleeve 4, and a fifth cavity 22 is formed between the other end cap 2 and the axial hole of the high-pressure valve sleeve 15. Moreover, a first cavity 18 and a sixth cavity 23 are respectively formed between the two push rods 3 and the two end caps 2. The first cavity 18 and the sixth cavity 23 are respectively installed corresponding to the second cavity 19 and the fifth cavity 22. Specifically, one end cap 2 is screwed or fixed to the main drain valve sleeve 4, and a second cavity 19 is formed between it and the axial hole of the main drain valve sleeve 4 to accommodate the reset mechanism 5. The other end cap 2 is screwed or fixed to the high-pressure valve sleeve 15, and a fifth cavity 22 is formed between it and the axial hole of the high-pressure valve sleeve 15 to accommodate the reset mechanism 5. A first cavity 18 and a sixth cavity 23 are respectively formed between the two push rods 3 and the two end caps 2. The first cavity 18 and the sixth cavity 23 control and move the corresponding push rod 3 by the pressure in the cavity itself.

[0029] Among them, a seventh radial hole k7 is formed in the end cap 2 close to the main drain valve sleeve 4. One end of the seventh radial hole k7 communicates with the first cavity 18, and the other end communicates with the output end of the corresponding first pilot mechanism I1.1. An eighth radial hole k8 is formed in the end cap 2 close to the high-pressure valve sleeve 15. One end of the eighth radial hole k8 communicates with the sixth cavity 23, and the other end communicates with the output end 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. By providing 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 through the seventh radial hole k7 and the eighth radial hole k8 respectively, adjust the pressures in the first cavity 18 and the sixth cavity 23, thereby acting on the corresponding push rod 3, moving the push rod 3 along the axial direction of the main valve body 12 of the hydraulic control, thereby moving the main valve body 12 of the hydraulic control, and realizing the on or off of the main valve body 12 of the hydraulic control. That is, by adjusting the pressures of the first cavity 18 and the sixth cavity 23, the moving speed of the push rod 3 can be controlled, thereby realizing continuous and smooth control of the opening amount, speed and flow rate when the main valve body 12 of the hydraulic control is on or off.

[0030] Furthermore, a first radial hole k1, a second radial hole k2, a third radial hole k3, and a main drain port A are sequentially arranged along the axial direction in the main drain valve sleeve 4, and a main liquid supply port P, a fourth radial hole k4, a fifth radial hole k5, and a sixth radial hole k6 are sequentially arranged along the axial direction in the high-pressure valve sleeve 15. One end of the first radial hole k1 communicates with the second cavity 19, and the other end communicates with a low-pressure liquid reflux port or an oil tank. One end of the second radial hole k2 communicates with the third accommodation chamber 20, and the other end communicates with the fourth radial hole k4 through an oil passage. One end of the third radial hole k3 communicates with the first annular groove, and the other end communicates with the main liquid supply port P through an oil passage. One end of the fourth radial hole k4 communicates with the second annular groove, and the other end communicates with the second radial hole k2 through an oil passage. One end of the fifth radial hole k5 communicates with the fourth cavity 21, and the other end communicates with a low-pressure liquid reflux port or a tank. One end of the sixth radial hole k6 communicates with the fifth cavity 22, and the other end communicates with a low-pressure liquid reflux port or a tank.

[0031] When the three-stage electro-hydraulic proportional control valve described in this embodiment specifically operates, it is as follows.

[0032] At the initial time point, the first pilot mechanism 1 is not operated, the pressures in the first cavity 18 and the sixth cavity 23 are both zero, the left push rod 3 abuts against the ball 8 at the corresponding position, but the ball port where this ball 8 is located is in a closed state, the right push rod disengages from the ball at the right end, and the disengaging distance is the stroke of the main valve body 12 of the hydraulic control. The main valve body 12 of the hydraulic control is in a closed state, that is, the P-A 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, and the left-end push rod 3 gradually moves to the right. The push rod 3 pushes the ball 8 away from the pilot valve seat 7 by a certain distance. The high-pressure liquid reaches the third radial hole k3 from the main liquid supply port P through the external passage. It reaches the third cavity 20 through the annular radial gap formed by the first radial small hole a, the sub-ball of the ball 8, the push rod 3, the pilot valve seat 7, and the clamping plug 6. When the pressure in the third cavity 20 rises to the on-pressure, the main valve body 12 of the hydraulic control moves to the right, and until the sub-ball of the ball 8 is re-closed, the main valve member P-A passage communicates to supply liquid outwards. In this way, the opening amount of the P-A passage of the main valve body 12 of the hydraulic control can be stably maintained. By repeating this process, until the main valve body 12 of the hydraulic control reaches the maximum opening amount, the stepping opening control of the main valve body 12 of the hydraulic control can be realized. At this time, the right-end push rod abuts against the right-end ball, and the first pilot mechanism I1.1 is quickly adjusted and controlled to make the pressure in the first cavity 18 zero. The left-end push rod 3 is moved by the reset mechanism 5 and returns to the initial zero position. The above proportional start-up process controls the pressure in the first cavity 18, that is, by controlling the displacement and speed of the push rod 3 to the right, continuous and smooth control of the opening amount, start-up speed, and flow rate of the start-up of the main valve body 12 of the hydraulic control can be realized.

[0034] For the first pilot mechanism II1.2, the same method as the above proportional starting process is adopted to move the right-end push rod to the left. 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 through the fifth radial hole k5. The main valve body 12 of the hydraulic control moves to the left, and until the ball port of the right-end ball is closed again, the opening amount of the main valve member P-A passage gradually decreases. By repeating this process, it can be realized that the opening amount of the main valve body 12 of the hydraulic control gradually decreases until the opening amount is closed to zero. At this time, the left-end push rod 3 abuts against the left-end ball 8. At this time, the first pilot mechanism II1.2 is adjusted and controlled to make the pressure in the first cavity 18 zero, and the right-end push rod is moved by the right-end reset mechanism to return to the initial zero position. The above proportional closing process can realize continuous and smooth control of the opening amount, closing speed, and flow rate when the main valve body 12 of the hydraulic control is closed by controlling the displacement and speed of the right-end push rod to the left.

[0035] Note that in this specification, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not require or imply any such actual relationship or order between these entities or operations. Also, the term "comprising", "including" or any other variation thereof is intended to include non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article or device. Without more limitations, an element limited by the phrase "comprising one..." does not exclude the existence of further other identical elements in addition to the process, method, article or device comprising the said element.

[0036] What has been described above are merely specific embodiments of the present disclosure, and those skilled in the art can understand or implement the present disclosure. Various modifications to these examples will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other examples without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not limited to these examples described herein, but rather conforms to the broadest scope consistent with the principles and novel features disclosed herein.

Explanation of Reference Signs

[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 seat 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. Fifth cavity 23. Sixth cavity a. First radial small hole b. Second radial small hole k1. First radial hole k2. Second radial hole k3. Third radial hole k4, the 4th radial hole, k5, the 5th radial hole, k6, the 6th radial hole, A, the main drain port, P, the main supply port.

Claims

1. a main valve member including a hydraulically controlled main valve element (12); a pilot member including a first pilot mechanism (1) and a second pilot mechanism, the first pilot mechanism including a first pilot mechanism I (1.1) and a first pilot mechanism II (1.2) having the same structure, the second pilot mechanism including 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) being connected to a same pressure source, the second pilot mechanism I (16) and the second pilot mechanism II (17) being coaxial with the hydraulically controlled main valve element (12) and being installed back to back at both ends of the hydraulically controlled main valve element (12), and both of the two second pilot mechanisms having a two-position two-port structure; A first cavity (18) and a sixth cavity (23) are respectively installed at outer ends of the second pilot mechanism I (16) and the second pilot mechanism II (17), the first cavity (18) is connected to a drain port of the first pilot mechanism I (1.1), and the sixth cavity (23) is connected to a drain port of the first pilot mechanism II (1.2), a reset mechanism (5) is further installed in the second pilot mechanism I (16) and the second pilot mechanism II (17), and the hydraulic a third cavity (20) and a fourth cavity (21) are respectively provided at both ends of a control main valve body (12), the third cavity (20) communicates with a drain port of the second pilot mechanism I (16), a liquid supply port of the second pilot mechanism I (16) communicates with a main liquid supply port (P), the third cavity (20) further communicates with a liquid supply port of the second pilot mechanism II (17), and the fourth cavity (21) communicates with a low pressure liquid return port or a tank.

2. The three-stage electrohydraulic 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 opening and closing valves and hydraulic resistances.

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 of 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 coaxially installed in the pilot valve seat (7); 2. The three-stage electrohydraulic 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 formed 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) 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 in the axial through-hole; and several radial fluid supply holes are formed in the pilot valve seat (7) at positions close to the other end of the pilot valve body.

4. 4. The three-stage electrohydraulic proportional control valve as claimed in claim 3, characterized in that a tightening plug (6) and the pilot member are sequentially installed inwardly along the axial direction on both ends of the hydraulic control main valve body (12), 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 an initial zero position when the pressure of the first pilot mechanism (1) is zero; The three-stage electrohydraulic proportional control valve as claimed in claim 3, characterized in that a second cavity (19) and a fifth cavity (22) are provided at positions corresponding to the reset mechanisms of the second pilot mechanism I (16) and the second pilot mechanism II (17) of the main valve member.

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) being connected in sequence along the axial direction of the hydraulic control main valve body (12); The hydraulically controlled main valve body (12) is a cone valve, and the valve stem of the hydraulically controlled main valve body (12) has a truncated cone. The left end valve stem of the hydraulically controlled main valve body (12) is installed in an axial hole at the right end of the main drain valve sleeve (4), and the third cavity (20) is formed between the left end face of the hydraulically controlled main valve body (12) and the main drain valve sleeve (4). The right end valve stem of the hydraulically controlled main valve body (12) is installed in an axial hole at the left end of the high-pressure valve sleeve (15), and the fourth cavity (21) is formed between the right end face of the hydraulically controlled main valve body (12) and the high-pressure valve sleeve (15).

6. The three-stage electro-hydraulic proportional control valve as claimed in claim 5, characterized in that: mounting holes are provided on two end surfaces of the hydraulically controlled main valve body (12) along the axial direction, the mounting holes are used for mounting the second pilot mechanism; a first radial small hole (a) and a second radial small hole (b) are provided on both ends of the hydraulically controlled main valve body (12), the positions of the first radial small hole (a) and the second radial small hole (b) are respectively connected to the corresponding guide sleeves (11); a first annular groove and a second annular groove are provided on both ends of the hydraulically controlled main valve body (12), the first annular groove and the second annular groove are respectively connected to the first radial small hole (a) and the second radial small hole (b).

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

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

Images