Electric control servo proportional controller of hydrostatic transmission unit

Abstract

The utility model discloses an electric control servo proportional controller of a hydrostatic transmission unit, which relates to the technical field of hydrostatic transmission control and comprises a first valve body, a second valve body, an electromagnet, a valve core and a feedback mechanism, the valve core is arranged in the second valve body; the electromagnet is arranged at one end of the second valve body and is in transmission connection with the valve core; one side of the first valve body is connected with one side of the second valve body; the feedback mechanism is arranged in the first valve body and the second valve body. The electric control servo proportional controller of the hydrostatic transmission unit is reasonable and ingenious in structure, moment of force is balanced through electromagnetic thrust of the proportional electromagnet and elastic force of the tension spring, the valve element, the second valve body and the first valve body are easy to machine, fit clearances are small, the leakage rate is small, the annular groove of the valve element and the annular groove of the second valve body are adopted for negative covering, and the sealing performance is good. The response speed of the valve element is higher and more sensitive, the valve element stroke of the controller is small, the error of the feedback mechanism is small, and the control precision is higher.

Description

TECHNICAL FIELD

[0001] The utility model relates to static liquid pressure drive control technical field, in particular to a kind of electric control servo proportional controller of static liquid pressure drive unit. BACKGROUND

[0002] With the development of agricultural machinery and engineering machinery, customers' requirements for the control system used in current agricultural machinery and engineering machinery are continuously improved.

[0003] The patent with the publication number CN110307203A discloses a servo variable mechanism for hydraulic pump motor, belonging to the field of hydraulic control. When a proportional electromagnet is connected with a certain size of current, the proportional electromagnet outputs a certain thrust. At this time, the valve core is pushed to move a corresponding displacement by overcoming the adjusting spring force. The oil flows into the valve through the oil inlet, and then flows into the variable adjusting cylinder through the working oil port, thereby pushing the servo cylinder to move to realize variable, and rotating the lever around the center point to move the valve sleeve, close the valve core and terminate the oil flow into the variable adjusting cylinder through the oil inlet, thereby realizing the fixed displacement of the hydraulic pump.

[0004] The existing mechanical control device has low control precision and control sensitivity for static liquid pressure drive unit, is inconvenient to operate, cannot be automatically controlled, and cannot meet the changing needs of customers and market. SUMMARY

[0005] The utility model aims at providing a kind of electric control servo proportional controller of static liquid pressure drive unit, make response speed faster more sensitive, feedback mechanism error is small, control precision is higher.

[0006] To achieve the above object, the utility model provides the following scheme:

[0007] The utility model provides a kind of electric control servo proportional controller of static liquid pressure drive unit, including first valve body, second valve body, electromagnet, valve core and feedback mechanism;The fourth oil channel, second oil channel, fifth oil channel, first oil channel and third oil channel are sequentially provided on the second valve body from one end to the other end;The first oil channel is connected with variable piston left cavity, the second oil channel is connected with variable piston right cavity, and the third oil channel is connected with the overflow port of high-pressure overflow valve in static liquid pressure drive unit;The fifth oil channel is a drain oil channel;The valve core is arranged in the second valve body, and the electromagnet is arranged in one end of the second valve body and is connected with the valve core in transmission;The valve core is used to control the communication and closure between the fourth oil channel, the second oil channel, the fifth oil channel, the first oil channel and the third oil channel;One side of the first valve body is connected with one side of the second valve body;The feedback mechanism is arranged in the first valve body and the second valve body, and the feedback mechanism is connected with variable piston in transmission in static liquid pressure drive unit.

[0008] Optionally, the center groove of the valve core is provided with an eccentric hole, and the valve core is connected with one end of a short cylindrical pin through the eccentric hole; the feedback mechanism comprises an eccentric shaft, two support frames, a tension spring, a long cylindrical pin and two feedback rods; one end of the eccentric shaft extends into the second valve body, penetrates the two support frames and the two feedback rods in sequence and is connected with the inner wall of the second valve body; one end of the two feedback rods extends into the middle groove of the variable piston; the other end of the feedback rod is connected with the middle part of the corresponding support frame through the long cylindrical pin; one end of the two support frames is in contact with the other end of the short cylindrical pin, and the other end of the two support frames is connected through the tension spring.

[0009] Optionally, the eccentric shaft is further provided with a spring and a spring gasket on the side of the support frame away from the feedback rod, and the spring gasket is in contact with the support frame; a first O-shaped ring is arranged between the eccentric shaft and the second valve body.

[0010] Optionally, a first metal gasket is arranged between the second valve body and the shell of the hydrostatic transmission unit.

[0011] Optionally, a second metal gasket is arranged between the first valve body and the second valve body.

[0012] Optionally, a clamping pad is arranged between the outer end of the eccentric shaft and the second valve body.

[0013] Optionally, the second valve body and the electromagnet are connected through a third screw.

[0014] Optionally, the other end of the second valve body is provided with a valve cover, and the valve cover is connected with the second valve body through a fourth screw.

[0015] Optionally, a second O-shaped ring is arranged between the valve cover and the second valve body.

[0016] Optionally, a third O-shaped ring is arranged between the electromagnet and the second valve body.

[0017] The utility model discloses relative to prior art has obtained following technical effect:

[0018] The electric control servo proportional controller of the hydrostatic transmission unit, the structure is reasonable and ingenious, reaches the balance of the moment through the electromagnetic thrust of proportional electromagnet and the elasticity of tension spring, and the valve core, the second valve body and the first valve body are simple to process, and the cooperation gap is small, so that the leakage amount is also small, the ring groove of the valve core and the ring groove negative cover of the second valve body are adopted, so that the response speed of the valve core is faster and more sensitive, the valve core stroke of the controller is small, the feedback mechanism error is small, and the control precision is higher. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings described in the following only represent some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0020] Fig. 1 It is a structure schematic view of the electric control servo proportional controller of the hydrostatic transmission unit in the present application.

[0021] Fig. 2 It is a top view sectional structure schematic view of the electric control servo proportional controller of the hydrostatic transmission unit in the present application.

[0022] Fig. 3 It is a lateral sectional structure schematic view of the electric control servo proportional controller of the hydrostatic transmission unit in the present application.

[0023] Fig. 4 It is a sectional structure schematic view of the second valve body in the electric control servo proportional controller of the hydrostatic transmission unit in the present application.

[0024] Explanation of reference signs:

[0025] 1, eccentric shaft; 2, first screw; 3, clamping pad; 4, second valve body; 5, first valve body; 6, second screw; 7, third screw; 8, electromagnet; 9, valve cover; 10, fourth screw; 11, first O-ring; 12, spring; 13, spring washer; 14, support frame; 15, tension spring; 16, long cylindrical pin; 17, feedback rod; 18, short cylindrical pin; 19, valve core; 20, second O-ring; 21, third O-ring; 22, second metal washer; 23, first metal washer; 24, second oil passage; 25, first oil passage; 26, fourth oil passage; 27, third oil passage; 28, fifth oil passage. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments only represent some of the embodiments of the present application, and for those skilled in the art, other embodiments can also be obtained without creative labor on the basis of these drawings.

[0027] In order to make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the present application will be further described in detail in combination with the drawings and specific embodiments.

[0028] As Figs. 1 to 4As shown, the embodiment provides an electrically-controlled servo proportional controller of a hydrostatic transmission unit, which comprises a first valve body 5, a second valve body 4, an electromagnet 8, a valve core 19 and a feedback mechanism; the second valve body 4 is sequentially provided with a fourth oil channel 26, a second oil channel 24, a fifth oil channel 28, a first oil channel 25 and a third oil channel 27 from one end to the other end; the first oil channel 25 is in communication with a left cavity of a variable piston, the second oil channel 24 is in communication with a right cavity of the variable piston, and the third oil channel 27 is in communication with an overflow port of a high-pressure overflow valve in the hydrostatic transmission unit; the fifth oil channel 28 is a drain oil channel; the valve core 19 is arranged in the second valve body 4, and the electromagnet 8 is arranged at one end of the second valve body 4 and in transmission connection with the valve core 19; the valve core 19 is used for controlling the communication and closure between the fourth oil channel 26, the second oil channel 24, the fifth oil channel 28, the first oil channel 25 and the third oil channel 27; one side of the first valve body 5 is connected with one side of the second valve body 4; the feedback mechanism is arranged in the first valve body 5 and the second valve body 4, and the feedback mechanism is in transmission connection with the variable piston in the hydrostatic transmission unit.

[0029] In the initial position, the third oil channel 27 is in communication with the first oil channel 25, high-pressure oil passes through the high-pressure overflow valve, enters the first oil channel 25 from the third oil channel 27, and control oil flows into the left cavity of the variable piston through the first oil channel 25; at this time, the second oil channel 24 and the fourth oil channel 26 are closed due to the action of the valve core 19, the second oil channel 24 is in communication with the fifth oil channel 28 due to the position of the valve core 19, and the fifth oil channel 28 is a drain oil channel and is in communication with the inside of the shell, which is a low-pressure oil channel; low-pressure oil enters the right cavity of the variable piston from the second oil channel 24, a pressure difference is formed between the left and right cavities of the variable piston, the variable piston moves to the right, and the pump unit reaches the maximum displacement.

[0030] In the embodiment, an eccentric hole is arranged on the center groove of the valve core 19, and the valve core 19 is connected with one end of a short cylindrical pin 18 through the eccentric hole; the feedback mechanism comprises an eccentric shaft 1, two support frames 14, a pull spring 15, a long cylindrical pin 16 and two feedback rods 17; one end of the eccentric shaft 1 extends into the second valve body 4, penetrates the two support frames 14 and the two feedback rods 17 in sequence, and is connected with the inner wall of the second valve body 4; one end of each of the two feedback rods 17 extends into the left cavity of the variable piston and the right cavity of the variable piston, respectively; the other end of the feedback rod 17 is connected with the middle part of the corresponding support frame 14 through one end of the long cylindrical pin 16; one end of each of the two support frames 14 is in contact with the other end of the short cylindrical pin 18, and the other end of each of the two support frames 14 is connected through the pull spring 15.

[0031] In the initial position, the eccentric hole arranged on the center groove of the valve core 19 is arranged at a position such that when the short cylindrical pin 18 is in contact with the two support frames 14, the valve core 19 is in an eccentric position; at this time, the first oil channel 25 and the third oil channel 27 are in communication, and the fourth oil channel 26 and the second oil channel 24 are kept disconnected.

[0032] In a more specific embodiment, one end of the second valve body 4 is fastened to the second valve body 4 by the valve cover 9 with the second O-ring 20 through four screw connections, and the other end is fastened to the second valve body 4 by the electromagnet 8 with the third O-ring 21 through four screw connections.

[0033] The valve core 19 is interference-fitted with the short cylindrical pin 18, which is press-fitted on the eccentric hole of the central groove of the valve core 19 and moves together with the valve core 19. Since the short cylindrical pin 18 on the valve core 19 is eccentric, it is not in the middle of the valve core 19, which leads to the initial state of the controller, i.e., the valve core 19 is biased towards the electromagnet 8. When the electromagnet 8 is energized, the valve core 19 moves accordingly.

[0034] One end of the feedback rod 17 extends into the variable piston groove and slides in the variable piston groove. The middle hole is penetrated by the eccentric shaft 1, and the other end is penetrated by the long cylindrical pin 16 and moves together with the feedback rod 17.

[0035] The eccentric shaft 1 is fixed on the second valve body 4 by the gasket 3 and screws. The lowermost part of the eccentric shaft 1 is inserted into the second valve body 4. The lower part of the eccentric shaft 1 is clearance-fitted with the second valve body 4. From bottom to top, the middle part of the eccentric shaft 1 penetrates the feedback rod 17, two support frames 14, spring washers 13, and springs 12 in turn. The upper part of the eccentric shaft 1 is equipped with the first O-ring 11 for sealing. Finally, the eccentric shaft 1 is fastened on the second valve body 4 by the gasket 3 and screws to prevent it from coming out.

[0036] The two support frames 14 penetrate the groove in the middle of the valve core 19 and contact the short cylindrical pins 18 thereon, respectively. At the same time, the two support frames 14 also contact the long cylindrical pins 16 on the feedback rod 17, respectively. The tail parts of the two support frames 14 are connected by the tension spring 15 and placed in the first valve body 5.

[0037] There is a second metal gasket 22 between the first valve body 5 and the second valve body 4 for sealing. There is a metal gasket between the second valve body 4 and the shell mounting surface for sealing. Finally, the second valve body 4 is fastened to the shell by four screw connections.

[0038] The utility model discloses a static hydraulic transmission system, which is characterized by the following: the pump unit is the maximum displacement in the initial state, and the initial state is as follows: the utility model is fastened on the shell with four screws, the head of feedback rod 17 is deeply in the slot in the middle of the variable piston of the pump, and is used as a feedback mechanism; because there is eccentric short cylindrical pin 18 on valve core 19, control oil will pass through the high-pressure overflow valve from third oil channel 27 to first oil channel 25 after assembly, and enter the left cavity of the variable piston, at this time, valve core 19 will separate second oil channel 24 from fourth oil channel 26, but because valve core 19 and second valve body 4 are gap fit, there will be a small amount of leakage, second oil channel 24 is communicated with fifth oil channel 28, fifth oil channel 28 is communicated with the inner cavity of the shell, and enters the oil drain port, therefore, oil port E is low pressure, at this time, the right variable piston cavity connected with second oil channel 24 is low pressure, the variable piston is variable from left to right, and the displacement of the pump is the maximum displacement, if electromagnet 8 does not work, it will be the maximum displacement all the time.

[0039] Working principle: because short cylindrical pin 18 on valve core 19 is eccentrically installed on valve core 19, so this makes third oil channel 27 and first oil channel 25 be in a communicating state, high-pressure oil passes through the high-pressure overflow valve from third oil channel 27 to first oil channel 25, control oil flows into the left variable piston cavity through first oil channel 25, at this time, second oil channel 24 and fourth oil channel 26 are closed due to the action of valve core 19, second oil channel 24 and fifth oil channel 28 are communicated due to the position of valve core 19, fifth oil channel 28 is the oil drain oil channel and is communicated with the inside of the shell, and is the low-pressure oil way, low-pressure oil enters the right cavity of the variable piston from second oil channel 24, and the left and right cavities of the variable piston form a pressure difference, so that the variable piston moves right, and the pump unit reaches the maximum displacement. The right movement of the variable piston makes feedback rod 17 in the middle slot of the variable piston slide, so that the head of feedback rod 17 moves right, and long cylindrical pin 16 at the tail of feedback rod 17 drives left support frame 14, so that left support frame 14 moves left, because tension spring 15 connects the two support frames 14, so that right support frame 14 also moves left, and short cylindrical pin 18 in the slot on valve core 19 in the middle of right support frame 14 is driven, so that valve core 19 moves left with short cylindrical pin 18, the size of the oil channel between first oil channel 25 and third oil channel 27 is reduced, at this time, the flow of the pump unit reaches a balance point and is stable at the maximum displacement.

[0040] When the electromagnet 8 is energized, a given current is given to make the electromagnet 8 thrust push the valve core 19 to the middle position, the valve core 19 in the second valve body 4 is in the middle position, so that the first oil way 25 is disconnected with the third oil way 27, the second oil way 24 is disconnected with the fourth oil way 26, the first oil way 25 and the second oil way 24 are communicated with the fifth oil way 28, all are low pressure oil, the pressure in the variable piston two end cavities is the same, so that the variable piston is kept in the middle position and does not move, the displacement of the pump unit reaches 0 displacement, at this time, there is no displacement output. When the valve core 19 is in the middle position, the head of the feedback rod 17 slides with the variable piston, at this time, the feedback rod 17 is perpendicular to the valve core 19, the feedback rod 17 rotates with the long cylindrical pin 16, and a fixed force arm is relatively formed, the distance of the force arm is the center distance between the eccentric shaft 1 and the short cylindrical pin 18 of the valve core 19, a torque is formed, which is the force arm x the thrust of the electromagnet 8, the left support frame 14 pulls the right support frame 14 through the tension spring 15, so that a counterforce arm is formed, the distance of the counterforce arm is the center distance between the eccentric shaft 1 and the long cylindrical pin 16 of the feedback rod 17, a torque is formed, which is the tension of the tension spring 15 x the counterforce arm, the two torques reach balance, and the valve core 19 is stably kept in the middle position.

[0041] When the electromagnet 8 is energized more, the valve core 19 is pushed to move again, at this time, the second oil way 24 is communicated with the fourth oil way 26 through the movement of the valve core 19, the high pressure oil enters the second oil way 24 from the fourth oil way 26 through the high pressure overflow valve, the control oil flows into the right variable piston cavity through the second oil way 24, at this time, the first oil way 25 is closed with the third oil way 27 due to the action of the valve core 19, the first oil way 25 is communicated with the fifth oil way 28 due to the position of the valve core 19, the fifth oil way 28 is a drain oil way and is communicated with the inside of the shell, which is a low pressure oil way, the low pressure oil enters the left cavity of the variable piston from the first oil way 25, and the variable piston left cavity forms a pressure difference, so that the variable piston moves left, and the pump unit reaches the maximum displacement. The left movement of the variable piston makes the feedback rod 17 in the middle groove of the variable piston slide, so that the head of the feedback rod 17 moves left, at this time, the feedback rod 17 rotates with the long cylindrical pin 16, and a fixed force arm is relatively formed, the distance of the force arm is the center distance between the eccentric shaft 1 and the short cylindrical pin 18 of the valve core 19, a torque is formed, which is the force arm x the thrust of the electromagnet 8; the tail long cylindrical pin 16 of the feedback rod 17 drives the right support frame 14 to move right, and the left support frame 14 also moves right due to the connection of the two support frames 14 by the tension spring 15, so that a counterforce arm is formed, the distance of the counterforce arm is the center distance between the eccentric shaft 1 and the long cylindrical pin 16 of the feedback rod 17, a torque is formed, which is the tension of the tension spring 15 x the counterforce arm, the middle contact short cylindrical pin 18 of the valve core 19 in the left support frame 14 drives the short cylindrical pin 18 to move, and the valve core 19 moves right, so that the valve core 19 moves right, the connection size between the first oil way 25 and the third oil way 27 is reduced, the two torques reach balance, and the valve core 19 is stably kept on the left side, at this time, the flow of the pump unit reaches a balance point, but the swash plate turns to the other side and is stably kept at the maximum displacement.

[0042] It should be noted that, for those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0043] The principles and implementation modes of the present application are described in the specification by applying specific examples, the above embodiment description is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in specific implementation modes and application scope. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. An electrically controlled servo proportional controller of a hydrostatic transmission unit, characterized by, The valve core is provided with an eccentric hole on the center groove, and the valve core is connected with one end of a short cylindrical pin through the eccentric hole; the feedback mechanism comprises an eccentric shaft, two support frames, a tension spring, a long cylindrical pin and two feedback rods; one end of the eccentric shaft extends into the second valve body, penetrates the two support frames and the two feedback rods in sequence, and is connected with the inner wall of the second valve body; one end of the two feedback rods extends into the middle groove of the variable piston; the other end of the feedback rod is connected with the middle part of the corresponding support frame through the long cylindrical pin; one end of the two support frames is in contact with the other end of the short cylindrical pin, and the other end of the two support frames is connected through the tension spring.

2. An electrically controlled servo-proportional controller of a hydrostatic transmission unit according to claim 1, characterized in that, The eccentric shaft is provided with a spring and a spring washer on the side away from the feedback rod, and the spring washer is in contact with the support frame; a first O-shaped ring is arranged between the eccentric shaft and the second valve body.

3. An electrically controlled servo-proportional controller of a hydrostatic transmission unit according to claim 2, characterized in that, A first metal washer is arranged between the second valve body and the shell of the hydrostatic transmission unit.

4. An electrically controlled servo-proportional controller for a hydrostatic transmission unit according to claim 1, characterized in that, A second metal washer is arranged between the first valve body and the second valve body.

5. An electrically controlled servo-proportional controller for a hydrostatic transmission unit according to claim 1, characterized in that, A clamping pad is arranged between the outer end of the eccentric shaft and the second valve body.

6. An electrically controlled servo-proportional controller for a hydrostatic transmission unit according to claim 2, characterized in that, The second valve body and the electromagnet are connected through a third screw.

7. An electrically controlled servo-proportional controller for a hydrostatic transmission unit according to claim 1, characterized in that, The other end of the second valve body is provided with a valve cover, and the valve cover is connected with the second valve body through a fourth screw.

8. An electrically controlled servo-proportional controller for a hydrostatic transmission unit according to claim 1, characterized in that, A second O-shaped ring is arranged between the valve cover and the second valve body.

9. An electrically controlled servo-proportional controller of a hydrostatic transmission unit according to claim 8, characterized in that, A third O-shaped ring is arranged between the electromagnet and the second valve body.

10. An electrically controlled servo-proportional controller for a hydrostatic transmission unit according to claim 1, characterized in that, ​

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