Electro-hydraulic proportional valve and insulation aerial work bucket oil supply system

Abstract

This application relates to the field of hydraulic control technology, and in particular to an electro-hydraulic proportional valve comprising: a valve body, a valve core, a first electromagnetic drive unit, and a second electromagnetic drive unit. The valve core is slidably mounted on the valve body. One end of the valve body has a first opening, and one side of the valve body has a first oil outlet and a second oil outlet. The outer peripheral wall of the valve core has multiple sets of inclined grooves. A lever is also hinged to the outside of the valve body. The other end of the valve body has a second opening, and an end cover is detachably installed at the second opening. The end cover has an interconnected adjustment cavity and a rotation cavity. An elastic connecting member and a guide member are installed in the adjustment cavity. An elastic rotating member is hinged in the rotation cavity, and one end of the elastic rotating member is hinged to the guide member. An upper limit screw and a lower limit screw are threaded onto the end cover. The electro-hydraulic proportional valve and the oil supply system for the insulated aerial work platform of this application can adjust the lower limit stroke and the upper limit stroke of the valve core.

Description

Technical Field

[0001] This application relates to the field of hydraulic control technology, and in particular to an electro-hydraulic proportional valve and an insulated high-altitude work bucket oil supply system. Background Technology

[0002] An electro-hydraulic proportional valve is a type of hydraulic valve that converts an input electrical signal into force or displacement proportionally, thereby continuously controlling parameters such as pressure and flow rate. A proportional valve consists of two parts: a DC proportional solenoid and a hydraulic valve. The hydraulic valve part is not significantly different from that of a general hydraulic valve, but the DC proportional solenoid differs from the solenoid used in a typical solenoid valve. Using a proportional solenoid allows for displacement and suction outputs proportional to a given current. Proportional valves can be classified into three main categories based on their control parameters: proportional pressure valves, proportional flow valves, and proportional directional valves.

[0003] For example, Chinese patent application number CN201610538483.X discloses an electromagnetic proportional valve, comprising: a valve body having a valve core receiving hole; a valve core housed in the valve core receiving hole in a manner operable relative to the valve body; and a drive device having: a drive rod extending into the valve core receiving hole and abutting against the valve core, and a drive body for driving the drive rod. The valve body has a pressure source port communicating with a pressure source, a tank port communicating with a tank, and a control port for outputting control pressure. By controlling the position of the valve core within the valve core receiving hole, the pressure source port or tank port is connected to the control port. The control pressure acts on the drive rod in the direction opposite to the thrust from the drive rod to the valve core.

[0004] Regarding the aforementioned technologies, the inventors believe that the following defects exist: In common proportional valves, the end of the valve core furthest from the drive device is usually a closed structure. This closed structure means that the upper and lower limits of the valve core's stroke are not adjustable. Consequently, the oil flow rate output from the proportional valve outlet can only be the maximum or minimum value. The maximum value may be above 10 L / min, and the minimum value may be below 1 L / min. This makes it difficult to meet the more precise flow rate and pressure adjustment requirements under special working conditions, and therefore impractical. Summary of the Invention

[0005] This application provides an electro-hydraulic proportional valve and an insulated high-altitude work platform oil supply system to improve the following technical problems: In common proportional valves, the end of the valve core furthest from the drive device is usually a closed structure. This closed structure means that the upper and lower limits of the valve core's stroke are not adjustable. Consequently, the oil flow rate output from the proportional valve outlet can only be the maximum or minimum value, which is insufficient to meet the more precise flow rate and pressure adjustment requirements under special working conditions, making it impractical.

[0006] In a first aspect, this application provides an electro-hydraulic proportional valve, which adopts the following technical solution: An electro-hydraulic proportional valve includes: a valve body, a valve core, a first electromagnetic drive unit, and a second electromagnetic drive unit. The valve core is slidably mounted on the valve body. One end of the valve body has a first opening, and one side of the valve body has a first oil outlet and a second oil outlet. The outer peripheral wall of the valve core has multiple sets of inclined grooves, one set of which corresponds to the first oil outlet and is used to control the flow rate, and the other set of which corresponds to the second oil outlet and is used to control the flow rate. The first electromagnetic drive unit and the second electromagnetic drive unit are both installed at the first opening. The first electromagnetic drive unit and the second electromagnetic drive unit are respectively used to drive the valve core to slide forward or backward. A lever is also hinged to the outside of the valve body. When the lever is rotated to its extreme positions at both ends, either the first oil outlet or the second oil outlet opens independently. The valve body has a second opening at the other end, and an end cap is detachably installed at the second opening. The end cap has an adjustment cavity and a rotation cavity that are interconnected. An elastic connector and a guide are installed sequentially in the adjustment cavity. An elastic rotating component is hinged in the rotation cavity. One end of the elastic rotating component is hinged to the guide. An upper limit screw and a lower limit screw are threaded on the end of the end cap away from the valve body. The upper limit screw, the guide, the elastic connector, and the valve core are arranged sequentially along the same central axis. The upper limit screw abuts against the end of the guide to limit the forward sliding limit of the valve core. The elastic rotating component has a limiting plane. When the lower limit screw abuts against the limiting plane, the valve core slides in the reverse direction to the limit position.

[0007] In one feasible technical solution of this application, the elastic connector includes a first connecting cylinder, a second connecting cylinder, and a stroke adjusting spring. The first connecting cylinder is fixed to the end of the valve core, the second connecting cylinder is fixed to the end of the guide member, and there is a gap between the first connecting cylinder and the second connecting cylinder. The two ends of the stroke adjusting spring are respectively sleeved into and abut against the first connecting cylinder and the second connecting cylinder.

[0008] In one feasible technical solution of this application, a first ring is provided at one end of the first connecting cylinder for one end of the stroke adjusting spring to abut against and connect to the valve core, and a second ring is provided at one end of the second connecting cylinder for the other end of the stroke adjusting spring to abut against and connect to the guide member.

[0009] In one feasible technical solution of this application, the elastic rotating member includes a first rotating shaft, a second rotating shaft, a rotating arm, and a torsion spring. The first rotating shaft and the second rotating shaft are arranged in parallel. The first rotating shaft is rotatably mounted in the rotating cavity. The guide member is provided with a rotating groove. The second rotating shaft is rotatably mounted in the rotating groove. One end of the rotating arm is vertically fixed to the first rotating shaft, and the other end of the rotating arm is vertically fixed to the second rotating shaft. The first rotating shaft passes through the torsion spring, and the two legs of the torsion spring abut against the rotating arm and the inner wall of the rotating cavity, respectively. The torsion spring is used to drive the rotating arm to always have a tendency to rotate toward the side of the upper limit screw.

[0010] In one feasible technical solution of this application, there are two limiting planes, and the two limiting planes are symmetrically arranged on opposite sides of the rotating arm, with one of the limiting planes being arranged close to the lower limit screw.

[0011] In one feasible technical solution of this application, the rotating arm is a plate-shaped structure, and the two ends of the rotating arm are respectively vertically connected to the middle of the first rotating shaft and the middle of the second rotating shaft. There are two torsion springs, and the two torsion springs are respectively located on opposite sides of the rotating arm.

[0012] In one feasible technical solution of this application, a sealing ring is provided at the connection between the end cap and the valve body to seal the second opening.

[0013] Secondly, this application provides an insulated high-altitude work platform oil supply system, which adopts the following technical solution: An insulated aerial work platform bucket oil supply system includes the aforementioned electro-hydraulic proportional valve and is used on an aerial work platform vehicle. The electro-hydraulic proportional valve is installed in the upper hydraulic system of the aerial work platform vehicle. The work platform has a first hydraulic power component driven by a small flow rate and a second hydraulic power component driven by a large flow rate. Both the first and second hydraulic power components are connected to an upper operating valve group. An oil supply line is provided between the upper operating valve group and the electro-hydraulic proportional valve. One oil inlet of the oil supply line is connected to the first oil outlet, and the other oil inlet of the oil supply line is connected to the second oil outlet. The first oil outlet is used to control the oil flow rate of the first hydraulic power component, and the second oil outlet is used to control the oil flow rate of the second hydraulic power component.

[0014] In one feasible technical solution of this application, the upper operating valve group has a plurality of conventional proportional valves arranged in sequence, and the upper hydraulic system of the aerial work vehicle has a reversing valve group, which has six electro-hydraulic proportional valves, wherein the tail-connected electro-hydraulic proportional valve is installed on the oil supply line.

[0015] In one feasible technical solution of this application, a one-way valve group is also provided on the oil supply line. The one-way valve group has two independent one-way valves. The oil supply line has one main oil line and two branch oil lines. The main oil line is located between the upper operating valve group and the one-way valve group. The two independent one-way valves are respectively located on the two branch oil lines.

[0016] In summary, this application includes at least one of the following beneficial technical effects: By adding an upper limit screw to prevent the valve core from sliding forward to its limit, the upper limit stroke of the valve core is adjustable. By adding a lower limit screw and an elastic rotating component, when the valve core slides in the reverse direction, it will drive the elastic rotating component to rotate together. When the limiting plane is rotated to the point where it is abutted by the lower limit screw, the elastic rotating component can no longer rotate, thus limiting the valve core from continuing to slide in the reverse direction. Therefore, the lower limit stroke of the valve core is adjustable. By adding the aforementioned adjustable stroke structure to the end of the valve core, the lower and upper limits of the valve core's stroke can be adjusted, thereby achieving more precise regulation of flow rate and delivery pressure. For example, by installing an electro-hydraulic proportional valve in a hydraulic oil supply system with very high flow and pressure, the maximum output flow rate and the minimum output flow rate can be reduced, thereby precisely controlling the flow rate and delivery pressure. This helps ensure smooth operation of the end oil circuit, preventing vibration problems during hydraulic component operation. It also helps control the pressure of the oil circuit, effectively ensuring that the oil pipe is not prone to rupture and the hydraulic components are not easily damaged, making it more practical. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional structural schematic diagram of the electro-hydraulic proportional valve according to an embodiment of this application.

[0019] Figure 2 This is a schematic diagram of the principle of the oil supply system for the insulated high-altitude work bucket according to an embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 10. Reversing valve assembly; 100. Electro-hydraulic proportional valve; 1. Valve body; 2. Valve core; 21. Inclined groove; 31. First electromagnetic drive unit; 32. Second electromagnetic drive unit; 4. End cover; 41. Adjusting cavity; 42. Rotating cavity; 43. Sealing ring; 5. Elastic connecting component; 51. First connecting cylinder; 511. First ring; 52. Second connecting cylinder; 521. Second ring; 53. Stroke adjusting spring; 6. Guide component; 61. Rotating groove; 7. Elastic rotating component; 71. First rotating shaft; 72. Second rotating shaft; 73. Rotating arm; 731. Limiting plane; 74. Torsion spring; 8. Upper limit screw; 9. Lower limit screw; 20. Oil supply circuit; 201. Main oil circuit; 202. Branch oil circuit; 30. Upper operating valve assembly; 300. Conventional proportional valve; 40. Check valve assembly; 400. Independent check valve. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0022] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0023] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0025] The following is in conjunction with the appendix Figure 1-2 This application will be described in further detail.

[0026] This application discloses an electro-hydraulic proportional valve. (Refer to...) Figure 1 The electro-hydraulic proportional valve includes: a valve body 1, a valve core 2, a first electromagnetic drive unit 31, and a second electromagnetic drive unit 32. The valve core 2 is slidably mounted on the valve body 1. One end of the valve body 1 has a first opening, and one side of the valve body 1 has a first oil outlet A6 and a second oil outlet B6. The outer peripheral wall of the valve core 2 has multiple sets of inclined grooves 21, one set of inclined grooves 21 corresponding to the first oil outlet A6 and used to control the flow rate, and another set of inclined grooves 21 corresponding to the second oil outlet B6 and used to control the flow rate. The first electromagnetic drive unit 31 and the second electromagnetic drive unit 32 are both installed at the first opening. The first electromagnetic drive unit 31 and the second electromagnetic drive unit 32 are used to drive the valve core 2 to slide in the forward or reverse direction, respectively. A lever 10 is also hinged to the outside of the valve body 1. When the lever 10 is rotated to the extreme positions at both ends, the first oil outlet A6 or the second oil outlet B6 opens alone. The other end of the valve body 1 has a second opening, and an end cover 4 is detachably installed at the second opening. An adjustment cavity 41 and a rotation cavity 42 are provided inside the end cover 4. An elastic connector 5 and a guide 6 are installed in sequence in the adjustment cavity 41. An elastic rotating component 7 is hinged in the rotation cavity 42. One end of the elastic rotating component 7 is hinged to the guide 6. An upper limit screw 8 and a lower limit screw 9 are threaded on the end of the end cover 4 away from the valve body 1. The upper limit screw 8, the guide 6, the elastic connector 5 and the valve core 2 are arranged in sequence along the same central axis. The upper limit screw 8 abuts against the end of the guide 6 to limit the limit stroke of the valve core 2 in the forward sliding direction. The elastic rotating component 7 has a limiting plane 731. When the lower limit screw 9 abuts against the limiting plane 731, the valve core 2 slides in the reverse direction to the limit position.

[0027] In this embodiment, the elastic connector 5 includes a first connecting cylinder 51, a second connecting cylinder 52, and a stroke adjusting spring 53. The first connecting cylinder 51 is fixed to the end of the valve core 2, and the second connecting cylinder 52 is fixed to the end of the guide member 6. There is a gap between the first connecting cylinder 51 and the second connecting cylinder 52. The two ends of the stroke adjusting spring 53 are respectively fitted into and abut against the first connecting cylinder 51 and the second connecting cylinder 52. One end of the first connecting cylinder 51 is provided with a first ring 511 for one end of the stroke adjusting spring 53 to abut against and connect to the valve core 2, and one end of the second connecting cylinder 52 is provided with a second ring 521 for the other end of the stroke adjusting spring 53 to abut against and connect to the guide member 6. The elastic connector 5 designed above has a simple structure, stable transmission, and is not easily shaken.

[0028] In this embodiment, the elastic rotating member 7 includes a first rotating shaft 71, a second rotating shaft 72, a rotating arm 73, and a torsion spring 74. The first rotating shaft 71 and the second rotating shaft 72 are arranged in parallel. The first rotating shaft 71 is rotatably mounted in the rotating cavity 42. A rotating groove 61 is provided on the guide member 6. The second rotating shaft 72 is rotatably mounted in the rotating groove 61. One end of the rotating arm 73 is vertically fixed to the first rotating shaft 71, and the other end of the rotating arm 73 is vertically fixed to the second rotating shaft 72. The first rotating shaft 71 passes through the torsion spring 74, and the two legs of the torsion spring 74 abut against the inner wall of the rotating arm 73 and the rotating cavity 42, respectively. The torsion spring 74 is used to drive the rotating arm 73 to always have a tendency to rotate toward the upper limit screw 8. There are two limiting planes 731, and the two limiting planes 731 are symmetrically arranged on the opposite sides of the rotating arm 73. One of the limiting planes 731 is arranged close to the lower limit screw 9.

[0029] The rotating arm 73 has a plate-like structure, with its two ends perpendicularly connected to the middle of the first rotating shaft 71 and the middle of the second rotating shaft 72, respectively. Two torsion springs 74 are located on opposite sides of the rotating arm 73. The elastic rotating component 7 designed above has a simple structure, stable operation, and is not easily loosened or shaken.

[0030] To improve the sealing performance between the end cap 4 and the valve body 1, a sealing ring 43 is provided at the connection between the end cap 4 and the valve body 1 to seal the second opening.

[0031] The beneficial technical effects of the electro-hydraulic proportional valve in this application embodiment are roughly as follows: By adding an upper limit screw 8 to prevent the valve core 2 from sliding forward to its limit, the upper limit stroke of the valve core is adjustable. By adding a lower limit screw 9, an elastic rotating part 7, and a guide part 6, when the valve core 2 slides in the reverse direction, it will drive the elastic rotating part 7 to rotate together. When the limiting plane is rotated to the point where it is abutted by the lower limit screw 9, the elastic rotating part 7 can no longer rotate, thus limiting the valve core 2 from continuing to slide in the reverse direction. Therefore, the lower limit stroke of the valve core is adjustable. By adding the aforementioned stroke-adjustable structure to the end of the valve core 2, the lower and upper limits of the valve core 2's stroke can be adjusted, thereby achieving more precise regulation of flow rate and delivery pressure. For example, by installing the electro-hydraulic proportional valve 100 in a hydraulic oil supply system with very high flow and pressure, the maximum output flow rate and minimum output flow rate can be reduced, thereby precisely controlling the flow rate and delivery pressure. This helps ensure the stability of the end oil circuit, preventing vibration problems during hydraulic component operation. It also helps control the pressure of the oil circuit, effectively ensuring that the oil pipe is not prone to rupture and the hydraulic components are not easily damaged, making it more practical.

[0032] Reference Figure 1 and Figure 2This application embodiment also provides an insulated aerial work platform bucket oil supply system, including the aforementioned electro-hydraulic proportional valve 100 and used on an aerial work platform vehicle. The electro-hydraulic proportional valve 100 is installed in the upper hydraulic system of the aerial work platform vehicle. The work platform has a first hydraulic power component driven by a small flow rate and a second hydraulic power component driven by a large flow rate. Both the first and second hydraulic power components are connected to an upper operating valve group 30. An oil supply circuit 20 is provided between the upper operating valve group 30 and the electro-hydraulic proportional valve 100. One oil inlet of the oil supply circuit 20 is connected to a first oil outlet A6, and the other oil inlet of the oil supply circuit 20 is connected to a second oil outlet B6. The first oil outlet A6 is used to control the oil flow rate of the first hydraulic power component, and the second oil outlet B6 is used to control the oil flow rate of the second hydraulic power component.

[0033] The upper operating valve group 30 has multiple conventional proportional valves 300 arranged in sequence. The upper hydraulic system of the aerial work platform has a reversing valve group 10, which has six electro-hydraulic proportional valves 100, among which the tail electro-hydraulic proportional valve 100 is installed on the oil supply line 20.

[0034] It has two independent check valves 400. The oil supply circuit 20 has one main oil circuit 201 and two branch oil circuits 202. The main oil circuit 201 is located between the upper operating valve group 30 and the check valve group 40. The two independent check valves 400 are respectively located on the two branch oil circuits 202.

[0035] By moving lever 10 to one side, the first oil outlet A6 is opened, thereby supplying oil to the first hydraulic power component connected to the working bucket. By turning the upper limit screw 8, the upper limit stroke of the valve core 2 in the forward sliding direction can be adjusted, thereby controlling and regulating the maximum flow rate of the first oil outlet A6. By moving lever 10 to the other side, the second oil outlet B6 is opened, thereby supplying oil to the second hydraulic power component connected to the working bucket. By turning the lower limit screw 9, the lower limit stroke of the valve core 2 in the reverse sliding direction can be adjusted, thereby controlling and regulating the minimum flow rate of the second oil outlet B6.

[0036] For example, the oil flow rate of the leveling cylinder on the working bucket is small, while the oil flow rate of the boom cylinder on the working bucket is large. Therefore, the upper limit screw 8 and the lower limit screw 9 are used to control the maximum (e.g., no more than 10L / min at the first oil outlet A6) and the minimum (e.g., no less than 20L / min at the second oil outlet B6) oil flow rate, respectively. The total oil supply of the entire oil circuit is 30L / min. When oil is supplied at the first oil outlet A6, the independent check valve 400 connected to the first oil outlet A6 can prevent oil backflow in the branch oil circuit 202 connected to the first oil outlet A6; when oil is supplied at the second oil outlet B6, the independent check valve 400 connected to the second oil outlet B6 can prevent oil backflow in the branch oil circuit 202 connected to the second oil outlet B6.

[0037] Because the hydraulic system of the aerial work platform needs to provide hydraulic power to various large equipment, the flow and pressure in the hydraulic circuit of the upper vehicle hydraulic system are extremely high, making it difficult to directly apply to the operating hydraulic circuit of the work bucket. In common aerial work platforms, a separate hydraulic circuit system with lower flow and pressure is usually required for the work bucket. This design is not only costly but also complex to control, which is not conducive to practical application.

[0038] Therefore, this application improves and applies the above-mentioned electro-hydraulic proportional valve 100, which can control the upper limit stroke of the forward sliding of the valve core 2 through the upper limit screw 8, control the position of the inclined groove 21, and limit the oil supply flow of the hydraulic cylinder at the first oil outlet A6 during the swing leveling operation of the working bucket to 10L / min or less. This changes the situation where the oil supply flow was 30L / min during the swing leveling operation of the working bucket before the improvement. The swing leveling operation of the working bucket requires a slow speed. A 30L / min oil supply flow would lead to excessive speed and safety, and would also lead to high temperature and high pressure in the entire oil supply system, which would make the oil supply pipe easy to rupture and the hydraulic components easy to be damaged. Stop the swinging and leveling operation of the work bucket, and move the lever 10 to the other side to open the second oil outlet B6 (close the first oil outlet A6). Control the lower limit stroke of the valve core 2 to slide in the opposite direction through the lower limit screw 9, and control the position of the inclined groove 21. Limit the oil supply flow of the hydraulic cylinder for the operation of the work bucket boom to 20L / min or more. The flow rate of 20L / min can also provide power for other operations on the vehicle without affecting the oil circuit. Therefore, the work bucket can share the original upper hydraulic system of the aerial work platform, which simplifies the oil circuit structure, greatly reduces costs and makes control simpler. It is conducive to ensuring the stability of the end oil circuit. The hydraulic components of the work bucket are not prone to shaking during operation. It is also conducive to controlling the pressure of the oil circuit, thereby effectively ensuring that the oil supply pipe of the work bucket is not prone to rupture and the hydraulic components are not prone to damage.

[0039] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electro-hydraulic proportional valve, comprising: The valve body (1), valve core (2), first electromagnetic drive unit (31), and second electromagnetic drive unit (32) are configured. The valve core (2) is slidably mounted on the valve body (1). One end of the valve body (1) has a first opening, and one side of the valve body (1) has a first oil outlet (A6) and a second oil outlet (B6). The outer peripheral wall of the valve core (2) has multiple sets of inclined grooves (21), one set of which corresponds to the first oil outlet (A6) and is used to control the flow rate, and the other set of which corresponds to the second oil outlet (B6) and is used to control the flow rate. The first electromagnetic drive unit (31) and the second electromagnetic drive unit (32) are both installed at the first opening. The first electromagnetic drive unit (31) and the second electromagnetic drive unit (32) are used to drive the valve core (2) to slide in the forward or reverse direction, respectively. A lever (10) is also hinged to the outside of the valve body (1). When rotated to the extreme positions at both ends, either the first oil outlet (A6) or the second oil outlet (B6) opens independently, characterized in that: The valve body (1) has a second opening at the other end, and an end cap (4) is detachably installed at the second opening. The end cap (4) has an adjustment cavity (41) and a rotation cavity (42) that are interconnected. An elastic connector (5) and a guide (6) are installed in sequence in the adjustment cavity (41). An elastic rotating member (7) is hinged in the rotation cavity (42). One end of the elastic rotating member (7) is hinged to the guide (6). The end of the end cap (4) away from the valve body (1) is threaded. The valve core (2) is equipped with an upper limit screw (8) and a lower limit screw (9). The upper limit screw (8), the guide (6), the elastic connector (5), and the valve core (2) are arranged sequentially along the same central axis. The upper limit screw (8) abuts against the end of the guide (6) to limit the maximum stroke of the valve core (2) in the forward direction. The elastic rotating member (7) has a limiting plane (731). When the lower limit screw (9) abuts against the limiting plane (731), the valve core (2) slides in the reverse direction to the limit position.

2. The electro-hydraulic proportional valve according to claim 1, characterized in that, The elastic connector (5) includes a first connecting cylinder (51), a second connecting cylinder (52), and a stroke adjusting spring (53). The first connecting cylinder (51) is fixed to the end of the valve core (2), and the second connecting cylinder (52) is fixed to the end of the guide (6). The first connecting cylinder (51) and the second connecting cylinder (52) have a gap. The two ends of the stroke adjusting spring (53) are respectively fitted into and abut against the first connecting cylinder (51) and the second connecting cylinder (52).

3. The electro-hydraulic proportional valve according to claim 2, characterized in that, One end of the first connecting cylinder (51) is provided with a first ring (511) for one end of the stroke adjusting spring (53) to abut against and connect to the valve core (2), and one end of the second connecting cylinder (52) is provided with a second ring (521) for the other end of the stroke adjusting spring (53) to abut against and connect to the guide member (6).

4. The electro-hydraulic proportional valve according to claim 1, characterized in that, The elastic rotating component (7) includes a first rotating shaft (71), a second rotating shaft (72), a rotating arm (73), and a torsion spring (74). The first rotating shaft (71) and the second rotating shaft (72) are arranged in parallel. The first rotating shaft (71) is rotatably mounted in the rotating cavity (42). The guide (6) is provided with a rotating groove (61). The second rotating shaft (72) is rotatably mounted in the rotating groove (61). One end of the rotating arm (73) is vertically fixed to the first rotating shaft (71), and the other end of the rotating arm (73) is vertically fixed to the second rotating shaft (72). The first rotating shaft (71) passes through the torsion spring (74), and the two legs of the torsion spring (74) abut against the inner wall of the rotating arm (73) and the rotating cavity (42), respectively. The torsion spring (74) is used to drive the rotating arm (73) to always have a tendency to rotate toward the upper limit screw (8).

5. The electro-hydraulic proportional valve according to claim 4, characterized in that, There are two limiting planes (731), and the two limiting planes (731) are symmetrically arranged on opposite sides of the rotating arm (73), with one of the limiting planes (731) being arranged close to the lower limit screw (9).

6. The electro-hydraulic proportional valve according to claim 4, characterized in that, The rotating arm (73) is a plate-shaped structure. The two ends of the rotating arm (73) are respectively vertically connected to the middle of the first rotating shaft (71) and the middle of the second rotating shaft (72). There are two torsion springs (74), and the two torsion springs (74) are respectively located on opposite sides of the rotating arm (73).

7. The electro-hydraulic proportional valve according to claim 1, characterized in that, A sealing ring (43) is provided at the connection between the end cap (4) and the valve body (1) to seal the second opening.

Images