Electric control valve

Abstract

The utility model discloses an electric control valve which comprises an electromagnetic valve set and a control valve body, and an oil channel inner hole and an oil inlet communicated with the oil channel inner hole are formed in the control valve body so that high-pressure oil at an outlet of a plunger pump can be led in. An oil duct inner hole in the control valve body is communicated with a control oil duct in the electromagnetic valve set, a valve sleeve is arranged in the oil duct inner hole in a sliding mode, an oil drainage port T, an oil duct A and an oil duct P which are communicated with an inner cavity of the valve sleeve are formed in the outer wall of the valve sleeve at intervals, and the oil inlet is communicated with the oil duct P. A shifting fork is rotationally arranged on the outer wall of the valve sleeve. The other end of the shifting fork penetrates out of the control valve body to be movably connected with a servo plunger in the plunger pump so as to drive the servo plunger to slide. A valve element is coaxially arranged in the valve sleeve in a sliding mode, control assemblies for limiting sliding of the valve element are arranged at the two ends of the control valve body, and the oil drainage opening T, the oil way A and the oil way P are connected and disconnected through sliding fit of the valve sleeve, the valve element and an inner hole of the oil way. The requirement for stepless regulation of load pressure and output flow of the plunger pump can be met, the structure of the control valve can be simplified, and the manufacturing cost of the plunger pump can be reduced.

Description

Technical Field

[0001] The utility model relates to an electric control valve, belonging to the technical field of hydraulic plunger pumps. Background Art

[0002] The control unit that controls the output flow of the hydraulic piston pump is called a control valve. It receives the external load pressure signal of the piston pump. According to the power setting value of the piston pump, the control valve automatically adjusts the output flow of the piston pump so that the product of the load and the flow is equal to a fixed power value, which is constant power control. Based on this characteristic, the control valve can also be said to be a feedback device for the piston pump to the external load signal.

[0003] The plunger pump control valve usually adopts full hydraulic control mode, such as Figure 1 As shown: the external load signal hydraulic oil acts on the left end face of the control valve core through the oil channel 1, and the hydraulic oil generates a hydraulic force on the left end face of the control valve core, overcoming the large and small spring preloads acting on the right side of the variable valve stem. The control valve core moves to the right and pushes the variable valve stem to the right. The working pin installed in the groove of the variable valve stem toggles the corresponding mechanism to control the opening and closing of the oil channel, indirectly controlling the output flow of the plunger pump. When the load oil pressure is high, the displacement of the variable valve stem to the right increases, and the working pin drives the corresponding mechanism to enlarge the gap of the servo chamber oil channel that controls the flow. The oil pressure entering the servo chamber overcomes the spring force and pushes the variable mechanism to reduce the output flow of the plunger pump, realizing the function of high load and low flow output.

[0004] It can be seen from the above structure that the adjusting screw adjusts the small spring preload, and the adjusting nut adjusts the large spring preload. When the plunger pump is set at the factory, after the adjusting screw and the adjusting nut are calibrated, the relationship between the load oil pressure and the output flow of the plunger pump will be mechanically limited and cannot be changed (unless the adjusting screw and the adjusting nut are manually adjusted). This mechanical limitation is actually unscientific, which is equivalent to the input power of the plunger pump being mechanically limited. Secondly, the control valve of this full hydraulic control method has a complex structure, high matching accuracy requirements, and great manufacturing difficulty, which to a certain extent limits its application development.

[0005] Therefore, there is an urgent need in the technical field to develop an electronically controlled control valve that can not only meet the needs of stepless regulation of load pressure and output flow, but also simplify the control valve structure and reduce the manufacturing cost of the plunger pump. Utility Model Content

[0006] The technical problem to be solved by the utility model is that the relationship between the load pressure and the output flow of the existing plunger pump control valve is mechanically limited and flexible control cannot be achieved, and the full hydraulic control valve has a complex structure and high manufacturing precision.

[0007] To solve the above technical problems, the present utility model provides an electronically controlled control valve, which can not only meet the requirements of stepless adjustment of load pressure and output flow rate, but also simplify the structure of the control valve and reduce the manufacturing cost of the piston pump.

[0008] To achieve the above technical objectives and reach the above technical effects, the present application is realized through the following technical solutions:

[0009] An electronically controlled control valve includes a solenoid valve group. A pilot oil port is provided on the solenoid valve group for connecting to the whole piston pump to provide a control pressure source. A control oil passage communicating with the pilot oil port is provided inside the solenoid valve group. The control valve body is further included. A circular oil passage inner hole is penetrated through the control valve body. An oil inlet communicating with the oil passage inner hole is provided on the outer wall of the control valve body to introduce the high-pressure oil at the outlet of the piston pump.

[0010] One end of the control valve body is fixedly connected to the solenoid valve group. The control oil passage is communicated with the oil passage inner hole. A valve sleeve is slidably arranged inside the oil passage inner hole. Drain ports T, oil passages A and P communicating with the inner cavity of the valve sleeve are spaced apart in the direction away from the control oil passage on the outer wall of the valve sleeve. The oil inlet is located on one side of the oil passage P away from the oil passage A and is communicated with the oil passage P. A fork is rotatably connected to the outer wall of the end of the valve sleeve away from the control oil passage. The other end of the fork penetrates out of the control valve body to be movably connected with a servo piston inside the piston pump to drive the servo piston to slide.

[0011] A valve core is coaxially and slidably penetrated inside the valve sleeve. Control components for restricting the sliding of the valve core are provided at both ends of the control valve body. The communication and cut-off between the drain port T and the oil passage A and the oil passage P are realized through the sliding fit of the valve sleeve, the valve core and the oil passage inner hole, and further the communication and cut-off between the drain port T and the oil passage A and the control end cavity of the servo piston are realized.

[0012] Preferably, the control components include a control cylindrical pin, an adjusting seat, a support spring and a spring seat. The control cylindrical pin is slidably arranged between the control oil passage and the oil passage inner hole. The end face of the control cylindrical pin extending into the oil passage inner hole abuts against the end face of the valve core. The adjusting seat is arranged on the inner wall of the end of the oil passage inner hole away from the control oil passage. The spring seat is slidably arranged in the oil passage inner hole in the direction of approaching or departing from the adjusting seat. One end of the support spring abuts against the end face of the adjusting seat facing the oil passage inner hole. The other end of the support spring is connected to the spring seat. The end face of the spring seat away from the adjusting seat abuts against the end face of the valve core.

[0013] Furthermore, a control spacer sleeve is clamped and fixed between the control oil passage and the oil passage inner hole. The control cylindrical pin slidably penetrates through the control sleeve, and the control cylindrical pin and the control sleeve are in small clearance fit.

[0014] Furthermore, the end of the control cylindrical pin that abuts the valve core is spherically arranged, the end of the spring seat that abuts the valve core is provided with a convex ball, and both ends of the valve core are respectively provided with ball sockets that match the spherical surface of the control cylindrical pin and the convex ball.

[0015] Furthermore, an end of the control valve body facing away from the solenoid valve group is provided with an adjusting component for fine-tuning the position of the adjusting seat in the inner hole of the oil channel, and the adjusting component includes an outer end cover, an adjusting nut and an adjusting screw. The outer end cover is detachably arranged on the end face of the control valve body, and the adjusting nut is arranged on the outer end cover. The adjusting screw is threadedly connected with the adjusting nut and passes through the outer end cover to extend into the inner hole of the oil channel, and the end of the adjusting screw extending into the inner hole of the oil channel abuts against the adjusting seat.

[0016] Furthermore, an O-ring is embedded on the outer wall of the adjustment seat and cooperates with the inner wall of the inner hole of the oil channel.

[0017] Preferably, a fixing pin is provided at one end of the fork connected to the valve sleeve, a circular hole that matches the gap with the fixing pin is provided on the outer wall of the valve sleeve, a fixing nut is threadedly connected on the outer wall of the control valve body, a fork is passed through one end of the fixing nut and matches the gap with the fork.

[0018] The electric control valve provided by the utility model has the following advantages:

[0019] The electric control valve of the utility model can realize stepless flow control and can also simplify the structure of the plunger pump control valve, reduce the manufacturing cost, and play an important role in the application and promotion of the plunger pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of the pure hydraulic control mode of the conventional control valve of the plunger pump;

[0021] Figure 2 This is a structural schematic diagram of an electric control valve of the utility model;

[0022] Figure 3 This is a schematic diagram of the cross-sectional structure of an electric control valve of the utility model;

[0023] Figure 4 This is a schematic cross-sectional structure diagram of the utility model mainly showing the connection relationship between the shift fork and the valve sleeve;

[0024] Figure 5 This is a schematic diagram of the control principle of an electric control valve of the utility model;

[0025] In the figure:

[0026] 1 - Solenoid valve group; 11 - Control oil passage; 2 - Control valve body; 21 - Inner hole of the oil passage; 22 - Oil inlet; 3 - Valve sleeve; 4 - Fork; 5 - Spool; 6 - Control component; 61 - Control cylindrical pin; 62 - Adjusting seat; 63 - Support spring; 64 - Spring seat; 641 - Convex ball; 7 - Control spacer; 8 - Adjusting component; 81 - Outer end cover; 82 - Adjusting nut; 83 - Adjusting screw; 9 - O-ring; 10 - Fixed pin; 12 - Fixed nut. Detailed implementation

[0027] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Refer to Figure 2 And Figure 3 , an electronically controlled control valve, including a solenoid valve group 1, the solenoid valve group 1 is provided with a pilot oil port for connecting to the whole plunger pump to provide a control pressure source. The solenoid valve group 1 is integrally formed with a control oil passage 11 communicating with the pilot oil port. When the solenoid valve group 1 is energized, the pilot hydraulic oil enters through the pilot oil port and enters the control oil passage 11 after being decompressed by the solenoid valve group 1. In this embodiment, the working principle of the solenoid valve group 1 is prior art and will not be elaborated too much.

[0029] Refer to Figures 2 - 4 , an electronically controlled control valve further includes a control valve body 2. The control valve body 2 is provided with a circular inner hole 21 of the oil passage penetrating through it. An oil inlet 22 communicating with the inner hole 21 of the oil passage is opened on the outer wall of the control valve body 2 to introduce the high-pressure oil at the outlet of the plunger pump. The solenoid valve group 1 is locked to one end face of the control valve body 2 by screws. The control oil passage 11 communicates with the inner hole 21 of the oil passage. A valve sleeve 3 is slidably installed in the inner hole 21 of the oil passage. Drain ports T, oil passages A, and oil passages P communicating with the inner cavity of the valve sleeve 3 are spaced apart from each other on the outer wall of the valve sleeve 3 in the direction away from the control oil passage 11. The oil inlet 22 is located on the side of the oil passage P away from the oil passage A and communicates with the oil passage P. A fork 4 is rotatably connected to the outer wall of the end of the valve sleeve 3 away from the control oil passage 11. The other end of the fork 4 passes through the control valve body 2 and is provided with an opening at the end to be movably connected to the servo plunger in the plunger pump to drive the servo plunger to slide.

[0030] Furthermore, a valve core 5 is coaxially slidably penetrated in the valve sleeve 3, and both ends of the valve core 5 extend out of the valve sleeve 3. Control components 6 that limit the sliding of the valve core 5 are installed at both ends of the control valve body 2. The oil drain port T and the oil channel A are connected and disconnected with the oil channel P through the sliding cooperation of the valve sleeve 3, the valve core 5 and the inner hole 21 of the oil channel, thereby realizing the connection and disconnection of the oil drain port T and the oil channel A with the control end cavity of the servo piston to achieve the purpose of controlling the output flow.

[0031] Reference Figures 2 - 4 The control assembly 6 includes a control cylindrical pin 61, an adjustment seat 62, a support spring 63 and a spring seat 64. The control cylindrical pin 61 is slidably installed between the control oil passage 11 and the oil passage inner hole 21. Specifically, the sliding of the control cylindrical pin 61 is driven by the pilot oil after the pressure reduction in the control oil passage 11. The end face of the control cylindrical pin 61 extending into the oil passage inner hole 21 abuts against the end face of the valve core 5. The adjustment seat 62 is inserted into the end of the oil passage inner hole 21 away from the control oil passage 11. The spring seat 64 is installed in the oil channel inner hole 21 so as to slide toward or away from the adjusting seat 62. One end of the support spring 63 is abutted against the end face of the adjusting seat 62 facing the oil channel inner hole 21. The other end of the support spring 63 is connected to the spring seat 64. The end face of the spring seat 64 facing away from the adjusting seat 62 abuts against the end face of the valve core 5. The sliding of the valve core 5 can be controlled by controlling the sliding of the cylindrical pin 61 or the spring seat 64 under the elastic force of the support spring 63.

[0032] Furthermore, a control spacer sleeve 7 is fixed between the control oil passage 11 and the oil passage inner hole 21. Specifically, shoulders are provided at the connecting parts of the control oil passage 11 and the oil passage inner hole 21 of the solenoid valve group 1 and the control valve body 2. The control spacer sleeve 7 is fixed by the shoulder limiter, and the control cylindrical pin 61 slides through the control sleeve, thereby ensuring the concentricity of the movement of the control cylindrical pin 61 and avoiding movement jamming. At the same time, the control cylindrical pin 61 cooperates with the control sleeve with a small gap, which on the one hand ensures the smoothness of the movement of the control spacer sleeve 7, and on the other hand avoids the control oil that reaches this place through the oil passage inner hole 21 from leaking due to the gap, thereby affecting the control accuracy.

[0033] Furthermore, the end of the control cylindrical pin 61 that abuts against the valve core 5 is spherically arranged, and the end of the spring seat 64 that abuts against the valve core 5 is integrally formed with a convex ball 641. Ball sockets matching the spherical surface of the control cylindrical pin 61 and the convex ball 641 are respectively provided at both ends of the valve core 5. At the same time, the outer circle of the valve core 5 and the inner hole of the valve sleeve 3 are matched with a small gap, which can not only realize flexible movement but also seal the high-pressure control oil.

[0034] Reference Figure 2 and Figure 3, an adjusting assembly 8 for finely adjusting the position of the adjusting seat 62 in the inner hole 21 of the oil passage is installed at one end of the control valve body 2 away from the solenoid valve group 1. The adjusting assembly 8 includes an outer end cover 81, an adjusting nut 82 and an adjusting screw 83. The outer end cover 81 is fixedly locked on the end face of the control valve body 2 by bolts. The adjusting nut 82 is fixed on the outer end cover 81 and is coaxially arranged with the valve core 5. The adjusting screw 83 is threadedly connected with the adjusting nut 82 and passes through the outer end cover 81 and extends into the inner hole 21 of the oil passage. One end of the adjusting screw 83 extending into the inner hole 21 of the oil passage abuts against the adjusting seat 62. Furthermore, the position of the adjusting seat 62 can be finely adjusted by rotating the adjusting screw 83, and at the same time, the pre-compression amount of the support spring 63 can be adjusted.

[0035] Furthermore, an O-ring 9 is embedded on the outer wall of the adjusting seat 62 to cooperate with the inner wall of the inner hole 21 of the oil passage to achieve the sealing of the oil fluid.

[0036] Refer to Figure 4 , in a further embodiment, a fixing pin 10 is inserted at one end of the fork 4 connected to the valve sleeve 3. A round hole with a clearance fit with the fixing pin 10 is opened on the outer wall of the valve sleeve 3. A fixing nut 12 is threadedly connected to the outer wall of the control valve body 2. One end of the fixing nut 12 passes through the fork 4 and has a clearance fit with the fork 4. One end of the fixing nut 12 inserted into the fork 4 and the fixing nut 12 are arranged in a stepped shape to limit the up and down freedom of the fork 4.

[0037] Refer to Figure 5 , the electro-control control valve is connected to the servo plunger and the rocker of the plunger pump through the fork 4. The servo plunger is provided with an L end and an R end, and the area of the L end is larger than that of the R end. The L end is the control end communicated with the oil passage on the valve sleeve 3, and the R end is in a state of constantly connected high-pressure oil. In this embodiment, taking the control cylindrical pin 61 being arranged at the left end of the valve core 5 as an example, the working principle of the electro-control control valve is as follows:

[0038] In the initial state, the high-pressure oil at the outlet of the plunger pump directly acts on the R end of the servo plunger through the internal oil passage. This oil fluid is constantly connected hydraulic oil. Since the solenoid valve is not energized at the L end of the servo plunger, the pilot oil pressure (low pressure) cannot generate a control pressure on the left side of the control cylindrical pin 61 through the solenoid valve group 1. The valve core 5 is driven by the driving force generated by the compression of the support spring 63 and moves to the left. The hydraulic oil at the outlet of the plunger pump reaches the oil passage P through the oil inlet 22. Since the valve core 5 is at the left side, the oil passage from P to A is closed, and the high-pressure oil cannot reach the L chamber of the servo plunger. The L chamber is connected to the oil drain port T at this time. Under the action of the constantly connected high oil pressure at the R end of the servo plunger, the servo plunger moves to the left, the rocker swing angle increases, and the control plunger pump outputs the maximum flow rate.

[0039] When the solenoid valve is energized, the pilot hydraulic oil acts on the left side of the control cylindrical pin 61 after being decompressed by the solenoid valve group 1, overcoming the spring force of the support spring 63 pushing the valve core 5 to the left. The valve core 5 moves to the right, the oil passage from P to A is connected, and the oil passage from A to T is closed. High-pressure oil enters the L chamber of the servo plunger. At this time, both ends of the servo plunger L and R are under the action of high-pressure oil. Since the area of the L end is larger than that of the R end, the servo plunger moves to the right, and the mechanism drives the rocker to swing to the right. The swing angle of the rocker decreases, and the output flow rate decreases.

[0040] When the servo plunger moves to the right, the cylindrical mating position of the fork 4 and the fixed nut 12 serves as the fulcrum, and the mating position of the opening of the fork 4 and the pin serves as the rotational driving point. The fork 4 drives the valve sleeve 3 to move to the right with the fixed pin 10. When it moves to the position where the oil passages P and A of the valve sleeve 3 and the valve core 5 are disconnected and A and T are connected, the high-pressure oil action at the L end of the servo plunger disappears. Under the action of the oil constantly flowing through the R end of the servo plunger, the servo plunger moves to the left, the swing angle of the rocker rises, and the output flow rate of the plunger pump becomes larger. When the servo plunger moves to the left, the fork 4 drives the valve sleeve 3 to move to the left with the fixed pin 10. At this time, P and A are connected again, and A and T are disconnected, and the output flow rate of the plunger pump becomes smaller again. In this way, the output flow rate is stabilized cyclically.

[0041] It can be seen that in combination with the system load pressure, as long as the pre-pressure of the support spring 63 is set reasonably, by changing the current applied to the solenoid valve group 1, stepless adjustment of the output flow rate of the plunger pump can be achieved, which perfectly solves the drawback that the output flow rate of traditional control valves cannot be adjusted due to mechanical limitations. Secondly, the electronic control structure is simple and the manufacturing cost is low.

[0042] The above is only the preferred embodiment of the present invention, and it is not a limitation to any form and essence of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the premise of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention. For those skilled in the art, without departing from the spirit and scope of the present invention, any equivalent changes, modifications and evolutions made by using the technical content disclosed above shall be equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An electronically controlled control valve, comprising a solenoid valve group (1). A pilot oil port is provided on the solenoid valve group (1) for connecting to the whole plunger pump to provide a control pressure source. A control oil passage (11) communicating with the pilot oil port is provided in the solenoid valve group (1), characterized in that, It also comprises a control valve body (2), wherein a circular oil passage inner hole (21) is formed through the control valve body (2), and an oil inlet (22) in communication with the oil passage inner hole (21) is formed on the outer wall of the control valve body (2) to allow the high-pressure oil at the outlet of the plunger pump to enter; One end of the control valve body (2) is fixedly connected to the solenoid valve group (1), the control oil passage (11) is connected to the inner hole (21) of the oil passage, a valve sleeve (3) is slidably arranged in the inner hole (21) of the oil passage, an oil drain port T, an oil passage A and an oil passage P which are connected to the inner cavity of the valve sleeve (3) are arranged at intervals on the outer wall of the valve sleeve (3) in a direction away from the control oil passage (11), an oil inlet (22) is located on a side of the oil passage P away from the oil passage A and is connected to the oil passage P, a shift fork (4) is rotatably connected to the outer wall of one end of the valve sleeve (3) away from the control oil passage (11), and the other end of the shift fork (4) passes through the control valve body (2) to be movably connected to a servo plunger in a plunger pump to drive the servo plunger to slide; A valve core (5) is coaxially slidably inserted in the valve sleeve (3), and control components (6) for limiting the sliding movement of the valve core (5) are provided at both ends of the control valve body (2). The oil drain port T and the oil passage A are connected and disconnected with the oil passage P through the sliding cooperation of the valve sleeve (3), the valve core (5) and the inner hole (21) of the oil passage, thereby realizing the connection and disconnection of the oil drain port T and the oil passage A with the control end cavity of the servo piston.

2. The electro-control control valve according to claim 1, characterized in that, The control assembly (6) comprises a control cylindrical pin (61), an adjustment seat (62), a support spring (63) and a spring seat (64); the control cylindrical pin (61) is slidably arranged between the control oil passage (11) and the oil passage inner hole (21); the end face of the control cylindrical pin (61) extending into the oil passage inner hole (21) abuts against the end face of the valve core (5); the adjustment seat (62) is arranged on the inner wall of the oil passage inner hole (21) away from the control oil passage (11); the spring seat (64) is slidably arranged in the oil passage inner hole (21) in a direction approaching or away from the adjustment seat (62); one end of the support spring (63) abuts against the end face of the adjustment seat (62) facing the oil passage inner hole (21); the other end of the support spring (63) is connected to the spring seat (64); the end face of the spring seat (64) away from the adjustment seat (62) abuts against the end face of the valve core (5).

3. An electro-control control valve according to claim 2, characterized in that, A control spacer sleeve (7) is fixed between the control oil passage (11) and the oil passage inner hole (21), and the control cylindrical pin (61) slides through the control spacer sleeve, and the control cylindrical pin (61) is matched with the control sliding sleeve with a small clearance.

4. An electro-control control valve according to claim 2, wherein, The end of the control cylindrical pin (61) that contacts the valve core (5) is spherically arranged, the end of the spring seat (64) that contacts the valve core (5) is provided with a convex ball (641), and both ends of the valve core (5) are respectively provided with ball sockets that match the spherical surface of the control cylindrical pin (61) and the convex ball (641).

5. An electronically controlled control valve according to claim 2, characterized in that, One end of the control valve body (2) facing away from the solenoid valve group (1) is provided with an adjusting assembly (8) for finely adjusting the position of the adjusting seat (62) in the inner hole (21) of the oil passage. The adjusting assembly (8) includes an outer end cover (81), an adjusting nut (82) and an adjusting screw rod (83). The outer end cover (81) is detachably arranged on the end face of the control valve body (2). The adjusting nut (82) is arranged on the outer end cover (81). The adjusting screw rod (83) is threadedly connected with the adjusting nut (82) and passes through the outer end cover (81) and extends into the inner hole (21) of the oil passage. One end of the adjusting screw rod (83) extending into the inner hole (21) of the oil passage abuts against the adjusting seat (62).

6. The electro-control control valve according to claim 2, wherein, An O-ring (9) is embedded on the outer wall of the adjusting seat (62) and is matched with the inner wall of the inner hole (21) of the oil passage.

7. An electronically controlled control valve according to claim 1, characterized in that, One end of the fork (4) connected to the valve sleeve (3) is provided with a fixing pin (10). A round hole with a clearance fit with the fixing pin (10) is arranged on the outer wall of the valve sleeve (3). A fixing nut (12) is threadedly connected to the outer wall of the control valve body (2). One end of the fixing nut (12) passes through the fork (4) and has a clearance fit with the fork (4).

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