Reverse follow-up flow control valve
By introducing a reverse follow-up design and hydraulic half-bridge structure into the flow control valve, the problem of restricted displacement of the main valve core is solved, the flow capacity is improved, and the accurate flow control is achieved through double closed-loop control, which solves the problem of restricted displacement of the main valve core, which is improved. The existing follower flow control valves have insufficient flow capacity and reliability.
Patent Information
- Application Number
- CN202110221335.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-02-27
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2041-02-27
AI Technical Summary
The follow-up flow control valve is difficult to improve its flow capacity under the same specifications, and increasing the amplification stage will lead to an increase in manufacturing cost and a reduction in reliability, mainly because the displacement of the main valve core is restricted by the displacement of the pilot valve core.
A reverse follow-up flow control valve is designed. Through the reverse motion relationship between the pilot valve core and the main valve core, the hydraulic half-bridge and large spring of the pilot valve port can be used to realize the dynamic opening of the main valve port, making a breakthrough. The displacement of the main valve core is restricted by the displacement of the pilot valve core, which improves the flow capacity, and forms a dual closed loop flow control through electrical displacement feedback to achieve accurate flow control.
It effectively improves the flow capacity of the flow control valve under the same specifications, overcomes the problem of restricted displacement of the main valve core, and at the same time realizes the accuracy of pressure differential compensation and flow control under variable load conditions.
Smart Images
Figure CN112747002B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to hydraulic control element technology, in particular to a hydraulic flow control valve. Background Art
[0002] The hydraulic flow control valve is a key hydraulic component in the hydraulic system. The follow-up feedback method has been widely used in hydraulic technology due to its advantages of good reliability and low cost. However, the displacement of the main valve core of the follow-up flow control valve is restricted by the displacement of the pilot valve core, making it difficult to improve the flow capacity under the same specifications. The method of increasing the number of amplification stages is bound to lead to an increase in manufacturing cost and a decrease in reliability. Summary of the invention
[0003] The object of the present invention is to provide a reverse follow-up flow control valve.
[0004] The present invention is a reverse follow-up flow control valve, comprising a main body 47, a control mechanism 48 and a valve sleeve displacement feedback mechanism 46. The control mechanism 48 and the main body 47 are threadedly connected to the pilot valve core 6 through a pilot valve connecting rod 8. The valve sleeve displacement feedback mechanism 46 and the main body 47 are threadedly connected to the valve sleeve 4 through a valve sleeve displacement feedback rod 13. The valve sleeve 4 is installed in the second step surface 16 of the valve body 1 and is connected to the valve body 1 through a large spring 2. The conical surface 30 of the main valve core 5 and the inner ring surface 28 of the valve sleeve 4 form a main valve port. The conical surface 32 of the pilot valve core 6 and the center hole 27 of the main valve core 5 form a pilot valve port. A small spring 7 is provided between the right end face 36 of the pilot valve core 6 and the left end face 49 of the rear end cover 9. The one-way valve 10 is in the flow channel 42 of the valve body 1. The fixed damping 12 is threadedly connected to the flow channel 43 of the valve body 1 and forms a C-type hydraulic half bridge with the pilot valve port.
[0005] Compared with the background technology, the present invention has the following specific beneficial effects: based on the basic principle of displacement follow-up feedback mode, the present invention proposes a displacement reverse follow-up feedback mode, which solves the problem that the displacement of the main valve core is restricted by the displacement of the pilot valve core, and the displacement of the main valve core cannot be greater than the displacement of the pilot valve core, thereby limiting the flow capacity. The design keeps the main valve core axially stationary, and the flange on the right end face of the main valve core fits the step surface of the valve body, and the rear end cover is pressed tightly against the right end face of the main valve core, so that the main valve core is axially fixed, and the oil passing through the pilot valve port forms a C-type hydraulic half bridge through fixed damping, and acts on the right annular surface of the valve sleeve, overcomes the large spring and moves to the left, and opens the main valve port. When the pilot valve core is opened, the valve sleeve moves in the opposite direction with the pilot valve core according to the follow-up ratio of n:1 (n>1), which can not only ensure the follow-up characteristics of the main valve port and the pilot valve port, but also break through the restriction of the displacement of the main valve core by the displacement of the pilot valve core, thereby improving the flow capacity of the flow control valve under the same specification conditions.
[0006] The main structure of the reverse follow-up control valve plus the electric displacement feedback constitute a double closed-loop flow control valve, which can realize the pressure difference compensation function of the main valve port under variable load conditions within the rated flow range, and the opening of the main valve port is proportional to the pilot valve port, thereby realizing accurate control of the valve port flow. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 is a cross-sectional view of the valve port of the present invention when it is closed, Figure 2 is a cross-sectional view of the valve port of the present invention when it is opened, Figure 3 It is a cross-sectional view of the structure of the present invention.
[0008] The reference numerals and corresponding names are: valve body 1, large spring 2, sealing ring 3, valve sleeve 4, main valve core 5, pilot valve core 6, small spring 7, pilot valve connecting rod 8, rear end cover 9, one-way valve ball 10, one-way valve spring 11, fixed damping 12, valve sleeve displacement trigger rod 13, control mechanism 14 (1), 14 (2), valve body first step surface 15, valve body second step surface 16, valve sleeve left end surface 17, valve body third step surface 18, valve sleeve first step surface 19, valve sleeve second step surface 20, compensation chamber flow channel 21, valve sleeve left annular surface 22, valve sleeve circumferential hole 23, valve The center threaded hole 24 of the sleeve, the inner cavity surface 25 of the valve sleeve, the right annular surface 26 of the valve sleeve, the center hole 27 of the valve core, the right annular surface 28 of the valve sleeve, the inner cavity annular surface 29 of the valve sleeve, the conical surface 30 of the main valve core, the left end surface 31 of the pilot valve core, the conical surface 32 of the pilot valve core, the inner cavity surface 33 of the main valve core, the cylindrical hole 34 of the pilot valve core, the right end surface 35 of the main valve core, the right end surface 36 of the pilot valve core, the threaded hole 37 at the tail of the pilot valve core, the left threaded surface 38 of the pilot valve core connecting rod, the end surface 39 of the rear end cover, the fourth step surface 40 of the valve body, the right end surface 49 of the main valve core, the boss surface 41 of the main valve core, the flow channel 42 of the valve body, the flow channel 43 of the valve body, the valve body P L Flow channel 44, valve body P H Flow channel 45, valve sleeve displacement feedback mechanism 46, main body 47, control mechanism 48, left oil port P H , Upper oil port P L . DETAILED DESCRIPTION
[0009] like Figure 1 to Figure 3As shown, the present invention is a reverse follow-up flow control valve, including a main body 47, a control mechanism 48 and a valve sleeve displacement feedback mechanism 46. The control mechanism 48 and the main body 47 are threadedly connected to the pilot valve core 6 through the pilot valve connecting rod 8. The valve sleeve displacement feedback mechanism 46 and the main body 47 are threadedly connected to the valve sleeve 4 through the valve sleeve displacement feedback rod 13. The valve sleeve 4 is installed in the second step surface 16 of the valve body 1 and is connected to the valve body 1 through the large spring 2. The conical surface 30 of the main valve core 5 and the inner ring surface 28 of the valve sleeve 4 form a main valve port, the conical surface 32 of the pilot valve core 6 and the central hole 27 of the main valve core 5 form a pilot valve port, the small spring 7 is between the right end face 36 of the pilot valve core 6 and the left end face 49 of the rear end cover 9, the one-way valve 10 is in the flow channel 42 of the valve body 1, and the fixed damping 12 is threadedly connected in the flow channel 43 of the valve body 1 and forms a C-type hydraulic half bridge with the pilot valve port.
[0010] Valve body 1 has two main oil ports, namely left oil port P H , Upper oil port P L , left side oil port P H Connect to the load, upper oil port P L Connect to the hydraulic system, left side oil port P H With upper oil port P L There is an O-type seal 3 in between.
[0011] The valve body 1 has two main oil ports, namely the left oil port P H , Upper oil port P L , left side oil port P H Connect to the load, upper oil port P L Connect to the hydraulic system, left side oil port P H With upper oil port P L There is an O-type seal 3 in between.
[0012] The inner cavity of the valve body 1 has four step surfaces, which are respectively the first step surface 15, the second step surface 16, the third step surface 18 and the fourth step surface 40 from left to right. The third step surface 18 and the first step surface 19 of the valve sleeve 4 form the left displacement dead point of the valve sleeve 4. The right side boss surface 41 of the main valve core 5 fits with the fourth step surface 40 of the valve body 1, and the left end surface 39 of the rear end cover 9 is pressed on the right end surface 49 of the main valve core, thereby limiting the axial position of the main valve core 5.
[0013] Upper oil port P L When oil enters, it passes through valve body P of valve body 1. L The flow channel 44 and the compensation chamber flow channel 21 act on the first step surface 19 and the second step surface 20 of the valve sleeve 4 to compensate for the liquid pressure on the inner cavity annular surface 29 of the valve sleeve 4.
[0014] The large spring 2, valve sleeve 4, main valve core 5, pilot valve core 6, small spring 7, pilot valve connecting rod 8, valve sleeve displacement feedback rod 13 and valve body 1 are coaxial.
[0015] The inner cavity of the valve body 1 has four step surfaces, which are respectively the first step surface 15, the second step surface 16, the third step surface 18 and the fourth step surface 40 from left to right. The third step surface 18 and the first step surface 19 of the valve sleeve 4 form the left displacement dead point of the valve sleeve 4. The right side boss surface 41 of the main valve core 5 fits with the fourth step surface 40 of the valve body 1, and the left end surface 39 of the rear end cover 9 is pressed on the right end surface 49 of the main valve core, thereby limiting the axial position of the main valve core 5.
[0016] Upper oil port P L When oil enters, the flow channel 44 of the valve body 1 and the compensation chamber flow channel 21 act on the first step surface 19 and the second step surface 20 of the valve sleeve 4, thereby compensating for the liquid pressure on the inner cavity annular surface 29 of the valve sleeve 4.
[0017] The left end of the pilot valve core 6 is designed with a flat conical surface 32, which is a single conical surface, or multiple conical surfaces, or a curved surface, or a combination of conical surfaces and curved surfaces. The conical surface 32 of the pilot valve core 6 and the central hole 27 of the main valve core 5 form a pilot valve port, and the oil port P L A fixed damper 12 and a one-way valve 10 are designed between the right end face 35 of the valve sleeve 4. The fixed damper 12 and the pilot valve port form a C-type hydraulic half bridge. The one-way valve 10 prevents the upper oil port P from L When high-pressure oil enters, the right end surface 35 of the valve sleeve 4 is acted upon by the liquid pressure.
[0018] The tail of the pilot valve core 6 is a threaded hole 37, which is connected to the left threaded surface 38 of the pilot valve connecting rod 8, and is connected to the control mechanism through the pilot valve connecting rod 8. The control mechanism is a stepper motor, or a servo motor, or a proportional solenoid, or a hydraulic drive piston 14. The center position of the valve sleeve 4 is a threaded hole 24, which is connected to the valve sleeve displacement feedback rod 13. It is connected to the feedback mechanism through the valve sleeve displacement feedback rod 13. The feedback mechanism is an LVDT displacement sensor.
[0019] The valve body 1 has two main oil ports, namely the left oil port P H , Upper oil port P L , left side oil port P H Connect to the load, upper oil port P L Connect to the hydraulic system, left side oil port P H With upper oil port P L There is an O-type seal 3 in between.
[0020] The working process of the present invention is as follows: Valve port closed state: When the upper oil port P LWhen it is the oil inlet, the annular surface 29 of the valve sleeve 4 and the liquid pressure on the first step surface 19 and the second step surface 20 of the left compensation chamber offset each other, and the one-way valve 10 prevents the oil from acting on the right end surface 35 of the valve sleeve 4. Under the pre-compression force of the large spring 2, the valve sleeve 4 is tightly pressed against the conical surface 30 of the main valve core 5, and the main valve port remains closed.
[0021] Follow-up opening process: left oil port P H For the oil inlet, the upper oil port P L For the working oil port:
[0022] When the control mechanism, i.e., the stepper motor, or the servo motor, or the proportional solenoid, or the hydraulic drive piston is not working, the pilot valve port is closed, the pressure on the right end face 35 of the valve sleeve 4 is low pressure, the valve sleeve 4 has no leftward hydraulic pressure, and the area of the annular surface 29 of the valve sleeve 4 is approximately equal to the area of the first step surface 19 and the second step surface 20 of the compensation chamber valve sleeve, so the upper oil port P L The pressure from the left oil port P H The entering high-pressure oil passes through the valve body flow channel 45 in the valve sleeve inner cavity 25, and the area of the annular surfaces 17 and 22 of the valve sleeve 4 is slightly larger than the area of the annular surface 26 on the right side of the valve sleeve 4. The valve sleeve 4 is tightly pressed against the conical surface 30 of the main valve core 5 under the action of the pre-compression force and the residual compression force of the large spring 2.
[0023] When the control mechanism, i.e., the stepper motor, or the servo motor, or the proportional solenoid, or the hydraulically driven piston is working, the pilot valve connecting rod 8 pulls the pilot valve core 6 to move to the right, the pilot valve port opens, and a C-type hydraulic half bridge is formed with the fixed damping 12. The pressure on the right end face 35 of the valve sleeve 4 increases, and a leftward liquid pressure is generated on the valve sleeve 4. When the force is greater than the sum of the pre-compression force and the residual compression force of the large spring 2, the valve sleeve 4 is pushed to move to the left, the main valve port opens, and a dynamic balance is achieved under the action of the liquid pressure on the right end face 35 of the valve sleeve and the large spring 2.
Claims
1. A reverse follow-up flow control valve, comprising a main body (47), a control mechanism (48) and a valve sleeve displacement feedback mechanism (46), characterized in that: The control mechanism (48) and the main body (47) are threadedly connected to the pilot valve core (6) through the pilot valve connecting rod (8), the valve sleeve displacement feedback mechanism (46) and the main body (47) are threadedly connected to the valve sleeve (4) through the valve sleeve displacement feedback rod (13), the valve sleeve (4) is installed in the second step surface (16) of the valve body, and is connected to the valve body (1) through the large spring (2), the main valve core conical surface (30) and the inner ring surface (28) of the valve sleeve (4) form a main valve port, the pilot valve core conical surface (32) and the center hole (27) of the main valve core (5) form a pilot valve port, a small spring (7) is provided between the right end surface (36) of the pilot valve core and the left end surface (49) of the rear end cover, the one-way valve (10) is in the first flow channel (42) of the valve body (1), and the fixed damping (12) is threaded. The valve body (1) is connected to a second flow channel (43) of the valve body (1); the valve body (1) has two main oil ports, namely a left oil port (PH) and an upper oil port (PL); the left oil port (PH) is connected to a load, and the upper oil port (PL) is connected to a hydraulic system; an O-type seal (3) is provided between the left oil port (PH) and the upper oil port (PL); the inner cavity of the valve body (1) has four step surfaces, which are, from left to right, a first step surface (15) of the valve body, a second step surface (16) of the valve body, a third step surface (18) of the valve body, and a fourth step surface (40) of the valve body; the third step surface (18) of the valve body and the first step surface (19) of the valve sleeve form the left displacement dead point of the valve sleeve (4); the right convex platform surface (41) of the main valve core (5) and the fourth step surface (40) of the valve body are connected to each other; 40) fits well, and the left end face (39) of the rear end cover presses on the right end face (49) of the main valve core, thereby limiting the axial position of the main valve core (5); when oil enters the upper oil port (PL), the valve body PL flow channel (44) and the compensation chamber flow channel (21) of the valve body (1) act on the first step surface (19) and the second step surface (20) of the valve sleeve on the left side of the valve sleeve (4), thereby compensating for the liquid pressure on the inner cavity annular surface (29) of the valve sleeve (4); the left end of the pilot valve core (6) is designed with a flat-headed conical surface (32), which is a single conical surface or multiple conical surfaces or a curved surface or a combination of conical surfaces and curved surfaces. The conical surface (32) of the pilot valve core (6) and the center hole (27) of the main valve core (5) form a pilot valve port, and the upper oil port (PL) and the right end face of the valve sleeve (4) are connected to each other. A fixed damper (12) and a one-way valve (10) are installed between the valve sleeve (4) and the pilot valve port. The fixed damper (12) and the pilot valve port form a C-shaped hydraulic half bridge. When the one-way valve (10) prevents the upper oil port (PL) from entering the high-pressure oil, the right end face (35) of the valve sleeve (4) is subjected to the action of the hydraulic pressure. The tail of the pilot valve core (6) is a threaded hole, which is connected to the left threaded surface (38) of the pilot valve connecting rod (8), and is connected to the control mechanism through the pilot valve connecting rod (8). The control mechanism is a stepping motor or a servo motor or a proportional solenoid or a hydraulic drive piston (14). The center position of the valve sleeve (4) is a threaded hole, which is connected to the valve sleeve displacement feedback rod (13), and is connected to the feedback mechanism through the valve sleeve displacement feedback rod (13). The feedback mechanism is an LVDT displacement sensor.
2. The reverse follow-up flow control valve according to claim 1, characterized in that: The large spring (2), valve sleeve (4), main valve core (5), pilot valve core (6), small spring (7), pilot valve connecting rod (8), valve sleeve displacement feedback rod (13) and valve body (1) are coaxial.