Motor control type high-water-base large-flow digital proportional valve

Abstract

The invention relates to the technical field of mining hydraulic valves, and discloses a motor control type high-water-base large-flow digital proportional valve which comprises a valve seat, a valve body is arranged in the valve seat, a pilot shaft is rotationally connected into the valve body, the outer surface of the pilot shaft is sleeved with a push rod, the push rod is movably connected with the valve body, and a constant-pressure cavity is formed between the push rod and the valve body. A cover plate is arranged at one end of the valve seat, the pilot shaft is arranged on the inner side of the cover plate, a sensitive cavity is formed between the push rod and the cover plate, and a low-pressure flow distribution hole and a high-pressure flow distribution hole are formed in the push rod. The pilot shaft is rotated through the pilot motor, and the pressure in the sensitive cavity is changed, so that the valve realizes the conversion of three working position states and three fluid channel connection modes according to the change of the pressure in the sensitive cavity, and meanwhile, through the synergistic effect of an accurate mechanical structure and a control system, the pressure in the sensitive cavity is reduced. And stable switching between different working states can be achieved, and various complex fluid control requirements are met.

Description

Technical Field

[0001] The invention relates to the technical field of mining hydraulic valves, in particular to a motor-controlled high-water-base large-flow digital proportional valve. Background Art

[0002] High-pressure, high-flow, water-based proportional directional valves are an important part of underground coal mining, and are also the core control components for coal mines to realize intelligence. High-performance, high-pressure, high-flow, water-based proportional directional valves are the basis for ensuring efficient coal mining in coal mines. The transmission medium of the water-based proportional directional valve is high water-based, which has the physical characteristics of low viscosity and easy leakage, and is mostly used in situations with high pressure and large flow. The sliding valve structure is easy to achieve proportional control, but there is a leakage problem. The cone valve structure can solve the emulsion leakage problem, but it is more difficult to achieve proportional control. Most of the underground coal mining uses two sets of two-position three-way switch reversing valves to realize the motion control of the oil cylinder, and the main valve is controlled by the pilot valve. The valve core is mostly conical, but the flow of the switch-type electro-hydraulic reversing valve is uncontrollable when it is started and there are problems such as huge hydraulic shock.

[0003] At present, Chinese patent CN102748482A discloses an electro-hydraulic proportional flow cone valve, which can realize arbitrary control of system flow, but the valve realizes a two-position two-way function, which is not suitable for reciprocating actuators such as oil cylinders. Chinese patent CN109555740A discloses a water-based proportional valve and its control method, which can realize precise posture adjustment of hydraulic supports in coal mines and reduce hydraulic shock, but it can only realize a two-position three-way function, and requires the assistance of a two-position two-way switch valve, and the structure is complex. Therefore, the development of a high-water-based reversing valve with low leakage, high reliability, and the ability to achieve flow ratio regulation is a technical problem that needs to be solved in the field of mining hydraulic valves.

[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the shortcomings of the prior art, the present invention provides a motor-controlled high-water-base large-flow digital proportional valve, which has the advantages of three-position three-way proportional control, fast response, high precision, low leakage, and no need for displacement sensor, solving the problem that the proportional valve can only realize two-position three-way function.

[0007] (II) Technical solution

[0008] In order to solve the technical problem that the motor-controlled high-water-base large-flow digital proportional valve can only realize the two-position three-way function, the present invention provides the following technical solutions:

[0009] A motor-controlled high-water-based large-flow digital proportional valve comprises a valve seat, wherein a valve body is arranged inside the valve seat, a pilot shaft is rotatably connected inside the valve body, a push rod is sleeved on the outer surface of the pilot shaft, the push rod is movably connected to the valve body, a constant pressure chamber is arranged between the push rod and the valve body, a cover plate is arranged at one end of the valve seat, the pilot shaft is arranged on the inner side of the cover plate, a sensitive chamber is arranged between the cover plates of the push rod, a low-pressure distribution hole and a high-pressure distribution hole are provided inside the push rod, a spiral groove is provided on the outer surface of the pilot shaft corresponding to the low-pressure distribution hole and the high-pressure distribution hole, a valve sleeve is fixedly connected to the inner side of the cover plate, a left cone valve and a right cone valve are arranged inside the valve body, the left cone valve and the right cone valve are sleeved on the outer surface of the push rod, a reset spring is fixedly connected between the left cone valve and the right cone valve, the valve sleeve and the valve body are provided with through holes corresponding to the left cone valve and the right cone valve, and the through holes are respectively P port, A port and T port;

[0010] The P port is used to introduce the high-pressure medium in the valve seat into the interior of the valve body, the T port is used to introduce the low-pressure medium in the valve body back to the return oil channel in the valve seat, and the A port is used to introduce the high-pressure medium of the valve body into the high-pressure channel of the valve seat. The left cone valve and the right cone valve are used to block the P port and the T port. When the medium flows into the sensitive cavity through the high-pressure distribution hole and the corresponding spiral groove on the pilot shaft, the push rod drives the left cone valve to move right so that the P port is connected with the A port. When the pilot shaft is rotated so that the high-pressure medium flows out of the sensitive cavity through the spiral groove corresponding to the pilot shaft and the low-pressure distribution hole, the push rod drives the right cone valve to move left so that the A port is connected with the T port.

[0011] Preferably, the outer surface of the pilot shaft is sleeved with a plurality of rotating sealing rings, which separate the two spiral grooves symmetrically arranged on the outer surface of the pilot shaft. A pilot motor is fixedly installed on the outer side of the cover plate, and the output end of the pilot motor is fixedly connected to the left end of the pilot shaft. A bearing is provided on the outer surface of the pilot shaft, and the pilot shaft is rotatably connected to the cover plate through the bearing.

[0012] Preferably, a channel a is opened inside the pilot shaft, a through hole a is opened on the inner wall of the channel a, the through hole a extends to the inside of the sensitive cavity, a through hole b is opened on the inner wall of the channel a corresponding to the left spiral groove, a through hole c is opened on the inner wall of the channel a corresponding to the right spiral groove, the right end face of the pilot shaft is blocked by a plug, a high-pressure oil channel and a low-pressure oil channel are opened inside the push rod, the high-pressure distribution hole is connected to the high-pressure oil channel, the low-pressure distribution hole is connected to the low-pressure distribution hole, a through hole d is opened on the wall of the left cone valve body, and an inner groove is arranged between the through hole d and the high-pressure distribution hole.

[0013] Preferably, the left cone valve and the right cone valve are both hollow structures, the right cone valve is sleeved on the right side of the push rod, and the left cone valve is sleeved on the left side of the push rod. Two retaining ring grooves are provided on the outer cylindrical surface of the push rod, and retaining rings are placed inside the retaining ring grooves. The retaining rings are provided at both ends of the left cone valve and the right cone valve.

[0014] Preferably, sliding sealing rings are provided at both ends of the push rod and the inner walls of the left cone valve and the right cone valve. The sliding sealing ring adopts a retaining ring and a star-shaped seal combination. A ball groove is opened on the valve body, and a ball socket is opened on the right side of the push rod. A small ball is arranged inside the ball socket, and the small ball is movably connected to the ball groove.

[0015] Preferably, O-ring sealing rings are arranged between the cover plate and the valve seat, between the valve sleeve and the valve body, and between the valve body and the valve seat.

[0016] (III) Beneficial effects

[0017] Compared with the prior art, the present invention provides a motor-controlled high-water-base large-flow digital proportional valve, which has the following beneficial effects:

[0018] 1. The present invention rotates the pilot shaft forward or reverses, so that the high water-based medium flows into the interior of the sensitive cavity through the high-pressure distribution hole and the corresponding spiral groove, or flows out of the sensitive cavity through the corresponding spiral groove and the low-pressure distribution hole, so that the pressure inside the sensitive cavity increases or decreases. The change in the pressure inside the sensitive cavity enables the push rod to drive the left cone valve to move right and connect the P port with the A port, or the push rod drives the right cone valve to move left and connect the A port with the T port. At the same time, when the pilot shaft is in the initial position, the P port, the A port, and the T port are not connected to each other. In summary, only by rotating the pilot shaft and changing the pressure inside the sensitive cavity, the valve can have three working position states and three fluid channel connection modes. At the same time, through the synergy of precise mechanical structure and control system, smooth switching between different working states can be achieved to meet various complex fluid control requirements.

[0019] 2. The present invention arranges a left cone valve and a right cone valve at the throttling part of the valve sleeve and the valve body. The left cone valve and the right cone valve are mainly sealed by a conical surface. A return spring can push the left cone valve and the right cone valve, so that the sealing performance of the left cone valve and the right cone valve when sealing the throttling part of the valve sleeve and the valve body can be guaranteed. This arrangement balances the force on the valve core and reduces the leakage of the emulsion.

[0020] 3. The present invention can realize the angle control of the pilot shaft by controlling the pilot motor. When the spiral groove on the pilot shaft is connected with the high-pressure distribution hole or the low-pressure distribution hole to form a throttle, the pressure in the sensitive chamber changes, and the hydraulic pressure pushes the push rod to move, thereby forming an electro-hydraulic servo spiral drive. In summary, the valve core displacement can be accurately controlled by controlling the angle of the pilot motor. Secondly, the pilot motor is only used for control, and the hydraulic pressure is used to drive the valve core, so that the installed power of the pilot motor is small.

[0021] 4. The present invention symmetrically opens two spiral grooves on the pilot shaft, so that after the pilot shaft completes the angle adjustment, the spiral grooves on its surface cooperate with the distribution holes to achieve flow control. Since the spiral grooves and the distribution holes are not sensitive to the cleanliness of the medium, the proportional valve as a whole has the characteristic of strong anti-pollution ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the motor-controlled high-water-base large-flow digital proportional valve of the present invention;

[0023] Figure 2 is a structural diagram of a push rod of the present invention;

[0024] Figure 3 It is a structural diagram of the motor pilot shaft of the present invention;

[0025] Figure 4 It is the structural diagram of the left and right cone valves of the present invention.

[0026] In the figure: 1. pilot motor; 2. cover plate; 3. pilot shaft; 4. push rod; 5. valve sleeve; 6. left cone valve; 7. return spring; 8. right cone valve; 9. valve body; 10. valve seat; 11. bearing; 12. sensitive chamber; 13. sliding sealing ring; 14. low-pressure chamber; 15. low-pressure distribution hole; 16. rotating sealing ring; 17. high-pressure distribution hole; 18. O-ring sealing ring; 19. retaining ring; 20. low-pressure oil channel; 21. small ball; 22. high-pressure oil channel; 23. constant pressure chamber; 24. plug. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] As introduced in the background technology, there are deficiencies in the prior art. In order to solve the above technical problems, the present application proposes a motor-controlled high-water-base large-flow digital proportional valve.

[0029] See also Figure 1-4 A motor-controlled high-water-based large-flow digital proportional valve comprises a valve seat 10, a valve body 9 is arranged inside the valve seat 10, a pilot shaft 3 is rotatably connected inside the valve body 9, a push rod 4 is sleeved on the outer surface of the pilot shaft 3, the push rod 4 is movably connected to the valve body 9, a constant pressure chamber 23 is arranged between the push rod 4 and the valve body 9, a cover plate 2 is arranged at one end of the valve seat 10, the pilot shaft 3 is arranged on the inner side of the cover plate 2, a sensitive chamber 12 is arranged between the cover plate 2 of the push rod 4, and a push rod 4 is opened inside A low-pressure distribution hole 15 and a high-pressure distribution hole 17, the outer surface of the pilot shaft 3 is provided with a spiral groove corresponding to the low-pressure distribution hole 15 and the high-pressure distribution hole 17, the inner side of the cover plate 2 is fixedly connected with a valve sleeve 5, the interior of the valve sleeve 5 is provided with a left cone valve 6 and a right cone valve 8, the left cone valve 6 and the right cone valve 8 are sleeved on the outer surface of the push rod 4, a return spring 7 is fixedly connected between the left cone valve 6 and the right cone valve 8, the valve sleeve 5 and the valve body 9 are provided with through holes corresponding to the left cone valve 6 and the right cone valve 8, and the through holes are respectively P port, A port, and T port;

[0030] The P port is used to introduce the high-pressure medium in the valve seat 10 into the valve body 9, the T port is used to introduce the low-pressure medium in the valve body 9 back to the return oil channel in the valve seat 10, and the A port is used to introduce the high-pressure medium of the valve body 9 into the high-pressure channel of the valve seat 10. The left cone valve 6 and the right cone valve 8 are used to block the P port and the T port. When the medium flows into the sensitive cavity 12 through the high-pressure distribution hole 17 and the corresponding spiral groove on the pilot shaft 3, the push rod 4 drives the left cone valve 6 to move right so that the P port is connected with the A port. When the pilot shaft 3 is rotated so that the high-pressure medium flows out of the sensitive cavity 12 through the spiral groove corresponding to the pilot shaft 3 and the low-pressure distribution hole 15, the push rod 4 drives the right cone valve 8 to move left so that the A port is connected with the T port.

[0031] By rotating the pilot shaft, the spiral groove on the pilot shaft 3 is connected to the high-pressure distribution hole 17 and is blocked from the low-pressure distribution hole 15. At this time, the high-water-based medium flows into the sensitive chamber 12 through the right spiral groove. As the pressure inside the sensitive chamber 12 increases, the push rod 4 is pushed to the right by the pressure, and the left cone valve 6 is opened. At this time, the high-pressure medium in the P port flows into the A port through the gap between the cone surface and the valve sleeve 5; similarly, by reversing the pilot shaft, the spiral groove on the pilot shaft 3 is connected to the low-pressure distribution hole 15, and the high-pressure distribution hole 17 is blocked from the spiral groove. The medium in the sensitive chamber 12 flows out through the low-pressure oil channel 20. The pressure inside the right constant pressure chamber 23 pushes the push rod 4 to move left and the right cone valve 8 to move left, and the A port is connected to the T port.

[0032] By rotating the pilot shaft 3 forward or reversely, the high water-based medium flows into the sensitive chamber 12 through the high-pressure distribution hole 17 and the corresponding spiral groove, or flows out of the sensitive chamber 12 through the corresponding spiral groove and the low-pressure distribution hole 15, so that the pressure inside the sensitive chamber 12 increases or decreases. The change in the pressure inside the sensitive chamber 12 enables the push rod 4 to drive the left cone valve 6 to move right and connect the P port with the A port, or the push rod 4 drives the right cone valve 8 to move left and connect the A port with the T port. At the same time, when the pilot shaft 3 is in the initial position, the P port, the A port, and the T port are not connected to each other. In summary, the valve can have three working position states and three fluid channel connection modes only by rotating the pilot shaft 3 and changing the pressure inside the sensitive chamber 12. At the same time, through the synergy of precise mechanical structure and control system, smooth switching between different working states can be achieved to meet various complex fluid control requirements.

[0033] Furthermore, for the above-mentioned pilot shaft 3, a plurality of rotating sealing rings 16 are sleeved on the outer surface of the pilot shaft 3, and the plurality of rotating sealing rings 16 separate the two spiral grooves symmetrically arranged on the outer surface of the pilot shaft 3. A pilot motor 1 is fixedly installed on the outer side of the cover plate 2, and the output end of the pilot motor 1 is fixedly connected to the left end of the pilot shaft 3. A bearing 11 is provided on the outer surface of the pilot shaft 3, and the pilot shaft 3 is rotatably connected to the cover plate 2 through the bearing.

[0034] The rotating sealing ring 16 can separate the two symmetrically arranged spiral grooves on the pilot shaft 3. Under the sealing of the rotating sealing ring 16, the leakage of high-water-based media from the cavity between the motor pilot shaft 3 and the push rod 4 can be reduced; the rotation angle of the pilot shaft 3 can be controlled by controlling the pilot motor 1. When the spiral groove on the pilot shaft 3 is connected to the high-pressure distribution hole 17 or the low-pressure distribution hole 15 to form a throttle port, the pressure in the sensitive cavity 12 changes, and the hydraulic pressure pushes the push rod 4 to move, thereby forming an electro-hydraulic servo spiral drive.

[0035] Further, for the above-mentioned pilot shaft 3, a channel a is opened inside the pilot shaft 3, a through hole a is opened on the inner wall of the channel a, and the through hole a extends to the inside of the sensitive cavity 12. A through hole b is opened on the inner wall of the channel a corresponding to the left spiral groove, and a through hole c is opened on the inner wall of the channel a corresponding to the right spiral groove. The right end face of the pilot shaft 3 is blocked by a plug 24, a high-pressure oil passage 22 and a low-pressure oil passage 20 are opened inside the push rod 4, the high-pressure distribution hole 17 is connected to the high-pressure oil passage 22, and the low-pressure distribution hole 15 is connected to the low-pressure distribution hole 15. A through hole d is opened on the inner wall of the left cone valve 6, and an inner groove is arranged between the through hole d and the high-pressure distribution hole 17.

[0036] Three inner grooves are formed inside the valve seat 10, which are respectively connected to the high-pressure channel P port, the low-pressure oil channel T port and the A port channel of the valve body 9, and are led to the outside of the valve seat 10 through the oil channel. An inner groove is provided between the through hole d and the high-pressure distribution hole 17 so that the high-pressure medium can enter the high-pressure distribution hole 17 without throttling. When the spiral groove on the pilot shaft 3 is connected to the high-pressure distribution hole 17 and is not connected to the low-pressure distribution hole 15, the high-pressure medium flows through the through hole d to reach the high-pressure distribution hole 17, and the high-pressure medium inside the high-pressure distribution hole 17 can flow into the sensitive cavity 12 through the channel a, the right spiral groove and the through hole a; when the spiral groove on the pilot shaft 3 is connected to the low-pressure distribution hole 15, and the high-pressure distribution hole 17 is not connected to the spiral groove, the medium in the sensitive cavity 12 flows out from the low-pressure oil channel 20 through the through hole a, the channel a, the left spiral groove and the through hole c.

[0037] Furthermore, for the above-mentioned left cone valve 6, the left cone valve 6 and the right cone valve 8 are both hollow structures, the right cone valve 8 is sleeved on the right side of the push rod 4, and the left cone valve 6 is sleeved on the left side of the push rod 4. Two retaining ring grooves are provided on the outer cylindrical surface of the push rod 4, and a retaining ring 19 is placed inside the retaining ring groove. The retaining ring 19 is provided at both ends of the left cone valve 6 and the right cone valve 8.

[0038] The left cone valve 6, the right cone valve 8 and the retaining ring 19 are not in contact in the original middle position, and there is a little gap, which ensures that the left cone valve 6 and the valve sleeve 5, and the right cone valve 8 are in contact and pressed against the valve body 9. The gap between the retaining ring and the two cone valves is the dead zone of the digital proportional valve, which can improve the stability of the system and avoid unnecessary fluctuations. The left end outer ring of the left cone valve 6 slides relative to the valve sleeve 5, and the right end cone surface and the end surface of the valve sleeve 5 have a throttling effect. The cone surface of the right cone valve 8 and the end surface of the valve body 9 also have a throttling effect. The smaller the opening, the greater the throttling effect.

[0039] Furthermore, for the above-mentioned push rod 4, both ends of the push rod 4 and the inner walls of the left cone valve 6 and the right cone valve 8 are provided with sliding sealing rings 13, and the sliding sealing ring 13 adopts a retaining ring and a star-shaped seal combination. A ball groove is opened on the valve body 9, and a ball socket is opened on the right side of the push rod 4. A small ball 21 is arranged inside the ball socket, and the small ball 21 is movably connected to the ball groove.

[0040] The setting of the sliding sealing ring 13 makes it difficult for the high water-based medium to leak when the push rod 4 moves. When the push rod 4 moves, it can drive the small ball 21 to roll inside the ball groove. At this time, the small ball 21 can limit the push rod 4 through the ball groove, so that the push rod 4 will not rotate when it moves.

[0041] Furthermore, for the above-mentioned cover plate 2 , O-ring sealing rings 18 are arranged between the cover plate 2 and the valve seat 10 , between the valve sleeve 5 and the valve body 9 , and between the valve body 9 and the valve seat 10 .

[0042] Under the seal of the O-ring seal 18, the cover plate 2 and the valve seat 10, the valve sleeve 5 and the valve body 9, and the valve body 9 and the valve seat 10 are tightly connected, thereby avoiding the phenomenon of medium leakage when the proportional valve is used.

[0043] Working principle:

[0044] When the pilot motor 1 is in the zero position, the low-pressure distribution hole 15 and the high-pressure distribution hole 17 are not connected to the spiral groove of the pilot shaft 3, the high- and low-pressure media will not enter the sensitive chamber 12, and the push rod 4 will not move. Under the action of the return spring 7, the conical surfaces of the left poppet valve 6 and the right poppet valve 8 respectively press the matching end surfaces of the valve sleeve 5 and the valve body 9, and also contact the left and right retaining rings 19, so that the push rod 4 returns to the middle position.

[0045] When the pilot motor 1 rotates forward by an angle, the spiral groove on the pilot shaft 3 communicates with the high-pressure distribution hole 17, but not with the low-pressure distribution hole 15. The high-water-based medium enters the channel a through the through hole c on the right spiral groove, and then enters the sensitive chamber 12. Since the effective area of ​​the sensitive chamber 12 is larger than the constant-pressure chamber 23, the thrust of the push rod 4 to the right is larger than the sum of the thrust of the constant-pressure chamber 23 to the left, the thrust of the left cone valve 6 to open, and the thrust of the return spring 7. The push rod 4 moves to the right, and the retaining ring 19 on the left pushes the left cone valve 6 to open. At this time, the high-pressure medium in the P port flows into the A port through the gap between the cone surface and the valve sleeve 5, realizing P to A. Under the action of the return spring 7 and the hydraulic pressure, the cone surface of the right cone valve 8 is in tight contact with the valve body 9, and no fluid passes through.

[0046] When the pilot motor 1 reverses a certain angle, the spiral groove on the pilot shaft 3 is connected to the low-pressure distribution hole 15, and the high-pressure distribution hole 17 is not connected to the spiral groove. The medium in the sensitive chamber 12 enters the spiral groove on the left side of the channel through the through hole a, channel a, and through hole b in turn, and then flows back to the T port through the low-pressure oil channel 20; the leftward thrust of the right constant pressure chamber 23 on the push rod 4 is greater than the force of opening the right cone valve 8, the compression force of the reset spring 7, and the thrust generated by the low pressure of the sensitive chamber 12. At this time, the push rod 4 moves left, the retaining ring 19 on the right side pushes the right cone valve 8 to move left, the A port is connected to the T port, and the cone surface of the left cone valve 6 presses the valve sleeve 5 under the action of the reset spring 7. The displacement of the valve core strictly corresponds to the rotation angle of the motor pilot shaft 3, and position servo control can be achieved without a displacement sensor.

[0047] The above technical solution is adopted: 1. By rotating the pilot shaft 3 forward or reversely, the high water-based medium flows into the inside of the sensitive chamber 12 through the high-pressure distribution hole 17 and the corresponding spiral groove, or flows out of the sensitive chamber 12 through the corresponding spiral groove and the low-pressure distribution hole 15, so that the pressure inside the sensitive chamber 12 increases or decreases. The change in the pressure inside the sensitive chamber 12 enables the push rod 4 to drive the left cone valve 6 to move right and connect the P port with the A port, or the push rod 4 drives the right cone valve 8 to move left and connect the A port with the T port. At the same time, when the pilot shaft 3 is in the initial position, the P port, the A port, and the T port are not connected to each other. In summary, it is only necessary to rotate the pilot shaft 3 and change the pressure inside the sensitive chamber 12 to make the valve have three working position states and three fluid channel connection methods. At the same time, through the synergy of precise mechanical structure and control system, it can realize smooth switching between different working states and meet various complex fluid control requirements; 2. By setting the left cone valve 6 and the right cone valve 8 at the throttling point of the valve sleeve 5 and the valve body 9, the left cone valve 6 and the right cone valve 8 are mainly blocked by the conical surface, and the return spring 7 can push the left cone valve 6 and the right cone valve 8, so that the sealing performance of the left cone valve 6 and the right cone valve 8 when blocking the throttling point of the valve sleeve 5 and the valve body 9 can be guaranteed. This setting balances the force of the valve core and reduces the leakage of the emulsion; 3. The angular control of the pilot shaft 3 can be realized by controlling the pilot motor 1. When the pilot shaft 3 is on When the spiral groove is connected with the high-pressure distribution hole 17 or the low-pressure distribution hole 15 to form a throttle, the pressure in the sensitive chamber 12 changes, and the hydraulic pressure pushes the push rod 4 to move, thereby forming an electro-hydraulic servo spiral drive. In summary, the valve core displacement can be accurately controlled by controlling the rotation angle of the pilot motor 1. Secondly, the pilot motor 1 is only used for control, and the hydraulic pressure is used to drive the valve core, so that the installed power of the pilot motor 1 is small; 4. Two spiral grooves are symmetrically opened on the pilot shaft 3, so that after the pilot shaft 3 completes the angle adjustment, the spiral grooves on its surface cooperate with the distribution holes to realize flow control. Since the spiral grooves and the distribution holes are not sensitive to the cleanliness of the medium, the proportional valve as a whole has the characteristics of strong anti-pollution ability.

[0048] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. A motor-controlled high water-base large flow digital proportional valve, comprising a valve seat (10), characterized in that: A valve body (9) is arranged inside the valve seat (10), and a pilot shaft (3) is rotatably connected inside the valve body (9). A push rod (4) is sleeved on the outer surface of the pilot shaft (3). The push rod (4) is movably connected to the valve body (9), and a constant pressure chamber (23) is arranged between the push rod (4) and the valve body (9). A cover plate (2) is arranged at one end of the valve seat (10), and the pilot shaft (3) is arranged on the inner side of the cover plate (2). A sensitive chamber (12) is arranged between the cover plate (2) of the push rod (4), and a low-pressure distribution hole (15) and a high-pressure distribution hole (23) are provided inside the push rod (4). The outer surface of the pilot shaft (3) is provided with spiral grooves corresponding to the low-pressure distribution hole (15) and the high-pressure distribution hole (17); the inner side of the cover plate (2) is fixedly connected with a valve sleeve (5); the interior of the valve sleeve (5) is provided with a left cone valve (6) and a right cone valve (8); the left cone valve (6) and the right cone valve (8) are sleeved on the outer surface of the push rod (4); a return spring (7) is fixedly connected between the left cone valve (6) and the right cone valve (8); the valve sleeve (5) and the valve body (9) are provided with through holes corresponding to the left cone valve (6) and the right cone valve (8); the through holes are respectively P port, A port and T port; The P port is used to introduce the high-pressure medium in the valve seat (10) into the interior of the valve body (9), the T port is used to introduce the low-pressure medium in the valve body (9) back to the oil return channel in the valve seat (10), and the A port is used to introduce the high-pressure medium in the valve body (9) into the high-pressure channel of the valve seat (10). The left cone valve (6) and the right cone valve (8) are used to block the P port and the T port. When the medium flows into the interior of the sensitive chamber (12) through the high-pressure distribution hole (17) and the corresponding spiral groove on the pilot shaft (3), the push rod (4) drives the left cone valve (6) to move rightward so that the P port is connected with the A port. When the high-pressure medium flows out of the interior of the sensitive chamber (12) through the corresponding spiral groove on the pilot shaft (3) and the low-pressure distribution hole (15) by rotating the pilot shaft (3), the push rod (4) drives the right cone valve (8) to move leftward so that the A port is connected with the T port.

2. The motor-controlled high water-base large flow digital proportional valve according to claim 1, characterized in that: The outer surface of the pilot shaft (3) is sleeved with a plurality of rotating sealing rings (16), and the plurality of rotating sealing rings (16) separate two spiral grooves symmetrically arranged on the outer surface of the pilot shaft (3). A pilot motor (1) is fixedly mounted on the outer side of the cover plate (2), and the output end of the pilot motor (1) is fixedly connected to the left end of the pilot shaft (3). A bearing (11) is arranged on the outer surface of the pilot shaft (3), and the pilot shaft (3) is rotatably connected to the cover plate (2) via the bearing.

3. A motor-controlled high water-base large flow digital proportional valve according to claim 2, characterized in that: A channel a is provided inside the pilot shaft (3), a through hole a is provided on the inner wall of the channel a, the through hole a extends to the inside of the sensitive chamber (12), a through hole b is provided on the inner wall of the channel a corresponding to the left spiral groove, a through hole c is provided on the inner wall of the channel a corresponding to the inner side of the right spiral groove, the right end face of the pilot shaft (3) is blocked by a plug (24), a high-pressure oil passage (22) and a low-pressure oil passage (20) are provided inside the push rod (4), the high-pressure distribution hole (17) is connected to the high-pressure oil passage (22), the low-pressure distribution hole (15) is connected to the low-pressure distribution hole (15), a through hole d is provided on the inner wall of the left cone valve (6), and an inner groove is provided between the through hole d and the high-pressure distribution hole (17).

4. The motor-controlled high water-base large flow digital proportional valve according to claim 3 is characterized in that: The left cone valve (6) and the right cone valve (8) are both hollow structures. The right cone valve (8) is sleeved on the right side of the push rod (4), and the left cone valve (6) is sleeved on the left side of the push rod (4). Two retaining ring grooves are provided on the outer cylindrical surface of the push rod (4). Retaining rings (19) are placed inside the retaining ring grooves. The retaining rings (19) are provided at both ends of the left cone valve (6) and the right cone valve (8).

5. The motor-controlled high water-base large flow digital proportional valve according to claim 4, characterized in that: Both ends of the push rod (4) and the inner walls of the left cone valve (6) and the right cone valve (8) are provided with sliding sealing rings (13), and the sliding sealing ring (13) is a combination of a retaining ring and a star-shaped seal. A ball groove is provided on the valve body (9), and a ball socket is provided on the right side of the push rod (4). A small ball (21) is provided inside the ball socket, and the small ball (21) is movably connected to the ball groove.

6. The motor-controlled high water-base large flow digital proportional valve according to claim 5, characterized in that: O-ring seals (18) are provided between the cover plate (2) and the valve seat (10), between the valve sleeve (5) and the valve body (9), and between the valve body (9) and the valve seat (10).

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