Multipurpose proportional control valve

Abstract

The utility model relates to the technical field of proportional control valves, in particular to a multipurpose proportional control valve. The oil return valve comprises a valve block, an ascending module and a descending module are installed on the valve block, and the valve block is provided with a pressure oil channel used for oil feeding, a first oil return channel used for oil returning and a second oil return channel used for oil returning. The rising module comprises an electromagnetic rising proportional valve and a pressure compensation valve which are integrally installed, one end of the rising proportional valve is connected to a pressure oil channel, the other end of the rising proportional valve is connected to an execution channel used for being connected with an oil cylinder, and the rear portion of the rising proportional valve is connected with a one-way valve module; the descending module comprises an electromagnetic descending proportional valve, the outlet end of the descending proportional valve is connected to the second oil return channel, and the descending proportional valve is further provided with an overflow valve module in parallel. The ascending module, the descending module, the overflow valve module and the one-way valve module are combined, the structure is compact, and the whole machine can be conveniently arranged under the condition that the space of a walking machine is limited.

Description

Technical Field

[0001] This utility model relates to the field of proportional control valve technology, specifically to a multi-purpose proportional control valve. Background Technology

[0002] Proportional control valves are common components in hydraulic systems. Their main function is to regulate the flow and pressure of hydraulic oil. For example, in agricultural and construction machinery, proportional control valves are often used to control the lifting, turning, and other actions of hydraulic cylinders. However, traditional proportional control valves, such as valve assemblies using cartridge valves and plate valves, typically have problems such as large size and large installation space requirements. Utility Model Content

[0003] The purpose of this invention is to provide a reasonably designed multi-purpose proportional control valve that addresses the defects and shortcomings of existing technologies, thereby solving the aforementioned deficiencies.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: It includes a valve block, on which a rising module and a falling module are mounted. The valve block is provided with a pressure oil channel for oil inlet and two return oil channels, namely, return oil channel one and return oil channel two. The rising module includes an electromagnetic rising proportional valve and a pressure compensation valve, which are installed as a single unit. One end of the rising proportional valve is connected to the pressure oil channel, and the other end is connected to the actuation channel for connecting the oil cylinder. A check valve module is connected behind the rising proportional valve. The falling module includes an electromagnetic falling proportional valve, the outlet end of which is connected to return oil channel two. An overflow valve module is also installed in parallel with the falling proportional valve.

[0005] Preferably, the proportional riser valve includes a proportional riser electromagnet with a manual operation button connected to the rear of the valve block. The front end of the proportional riser electromagnet is connected to a pressure balancing pin for the valve core. The pressure balancing pin for the valve core has an external thread. A valve core positioning seat is installed inside the valve block via a step. The tail end of the pressure balancing pin for the valve core also has a stepped structure, and a valve core spring is installed at the front end of the step. The front end of the valve core spring abuts against the valve core positioning seat for the valve core. A valve core is installed at the front end of the valve core positioning seat for the valve core. A guide pin is installed on the inner side of the front end of the valve core for the valve core. Both the guide pin and the valve core for the valve core have internal threads and are installed on the pressure balancing pin for the valve core for the valve core via the threads. The pressure oil passage inside the valve block is located at the front end of the valve core for the valve core. The outlet of the proportional riser valve is located on the outer side of the middle part of the valve core for ...

[0006] Preferably, the pressure compensation valve includes a positioning screw inserted into the valve block, the top of the positioning screw being located in the pressure oil passage, a pressure compensation valve plug installed at the front end of the valve block, a pressure compensation valve core installed inside the pressure compensation valve plug, and a pressure compensation valve spring between the two, the rear end of the pressure compensation valve core abutting against the positioning screw, a return oil passage being located outside the pressure compensation valve core, and a pressure feedback throttling orifice being provided at the rear end of the pressure compensation valve core, the pressure feedback throttling orifice being connected to the outlet of the rising proportional valve.

[0007] Preferably, the descent proportional valve includes a descent proportional electromagnet with a manual operation button installed on the rear side of the valve block. A descent valve sleeve is installed inside the valve block at the front end of the descent proportional electromagnet. A descent valve core that can slide inside the descent valve sleeve is connected to the front end of the descent proportional electromagnet. The execution channel is connected to the outside of the descent valve sleeve. The front end of the descent valve core is connected to the second return oil channel. An oil groove is provided inside the descent valve core. By moving the valve core, the opening and closing of the execution channel and the first return oil channel, as well as the cross-sectional size of the oil flow, can be controlled through the oil groove. A descent speed adjustment rod is also installed on the valve block directly in front of the descent valve core by threads. A spring support is connected to the rear end of the descent speed adjustment rod. A descent spring is provided between the spring support and the descent valve core.

[0008] Preferably, the one-way valve module includes a one-way valve plug installed on the valve block, a one-way valve core is provided inside the one-way valve plug, and a one-way valve spring is provided between the two. The chamber at the front end of the one-way valve core is connected to the execution channel. A hole is opened in the one-way valve core, and the hole connects the execution channel and the spring cavity where the one-way valve spring is located.

[0009] Preferably, the overflow valve module includes an overflow valve plug mounted on the valve block, an overflow valve conical spring inside the overflow valve plug, an overflow valve small module inside the overflow valve conical spring, an overflow valve small module including an overflow valve spring support attached to the rear of the overflow valve conical spring, an overflow valve core mounted inside the overflow valve spring support, an overflow valve spring between the outer side of the overflow valve core and the overflow valve spring support, an overflow valve sleeve connected to the rear end of the overflow valve core by a thread, and the spring cavity where the overflow valve spring is located is connected to the execution channel through a connection port opened in the valve block.

[0010] Preferably, the pressure balancing pin of the rising valve core has a small hole connecting its front head and its outer tail end.

[0011] Preferably, the rear end of the overflow valve core has a hexagonal center hole for controlling rotation.

[0012] Preferably, the valve block is further provided with a sealing nut at the opening where the descent speed adjusting rod is installed, and the front end of the descent speed adjusting rod is provided with an internal hexagonal adjustment hole for adjustment.

[0013] The beneficial effects of this utility model after adopting the above structure are:

[0014] 1. This utility model is used to control a single-acting hydraulic cylinder to achieve proportional control of the cylinder's upward and downward movement. It can be used, for example, for the electronic lifting of a tractor lift and to control the tillage depth of the implement; it can also be used for contour control of the mowing depth of a lawnmower robot, etc., and has a wide range of applications.

[0015] 2. This utility model combines the design of the rising module, the falling module, the overflow valve module and the one-way valve module, resulting in a compact structure. Compared with similar valve groups that use cartridge valves and plate valves to achieve the same function, the size is greatly reduced, making it easier to arrange the whole machine in situations where the space of the traveling machinery is limited.

[0016] 3. This utility model has manual operation buttons for both the raising and lowering functions. In special circumstances where the electromagnet is not energized due to electrical failure or other reasons, manual operation can still be used to ensure the reliability of control.

[0017] 4. This utility model designs a cone sealing structure for a one-way valve to ensure that the oil cylinder has no leakage when it is in the neutral position of the proportional valve, prevents the oil cylinder from sinking automatically, and improves system stability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the external structure of this utility model;

[0019] Figure 2 This is a bottom view of the present invention;

[0020] Figure 3 This is a front view of the present invention;

[0021] Figure 4 This is a top view of the present invention;

[0022] Figure 5 This is a left view of the present invention;

[0023] Figure 6 This is a schematic diagram of the working principle of this utility model;

[0024] Figure 7 This is a cross-sectional view of the one-way valve in this utility model;

[0025] Figure 8 This is an exploded view of the one-way valve in this utility model;

[0026] Figure 9 This is a cross-sectional view of the overflow valve in this utility model;

[0027] Figure 10 This is an exploded view of the overflow valve in this utility model;

[0028] Figure 11 This is a hydraulic schematic diagram illustrating the control of the cylinder's upward movement during operation of this utility model.

[0029] Figure 12 This is a cross-sectional view of the rising proportional valve in this utility model;

[0030] Figure 13 This is an exploded view of the rising proportional valve in this utility model;

[0031] Figure 14 This is a cross-sectional view of the proportional valve for lowering the height in this utility model;

[0032] Figure 15 This is an exploded view of the proportional valve for lowering the distance in this utility model.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Pressure compensation valve; 2. Rising proportional valve; 3. Falling proportional valve; 4. Check valve module; 5. Relief valve module; 6. Rising module; 7. Falling module; 8. Pressure feedback throttle orifice;

[0035] 201. Pressure compensating valve plug; 202. Pressure compensating valve spring; 203. Pressure compensating valve core; 204. Positioning screw; 205. Guide pin; 206. Lifting valve core; 207. Lifting valve core positioning seat; 208. Lifting valve core spring; 209. Lifting valve core pressure balance pin; 2010. Lifting proportional electromagnet;

[0036] 301. Sealing nut; 302. Lowering speed adjusting rod; 303. Spring support; 304. Lowering spring; 305. Lowering valve core; 306. Lowering valve sleeve; 307. Lowering proportional electromagnet;

[0037] 401. Check valve plug; 402. Check valve spring; 403. Check valve spool;

[0038] 501. Relief valve plug; 502. Relief valve conical spring; 503. Relief valve spring support; 504. Relief valve spring; 505. Relief valve core; 506. Relief valve sleeve;

[0039] A. Execution channel; P. Pressure oil channel; T1. Return oil channel one; T2. Return oil channel two; B. Rising proportional valve outlet; α. Connection port. Detailed Implementation

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0041] See Figures 1-6 As shown, it includes a valve block, on which an ascending module 6 and a descending module 7 are mounted. The valve block is provided with a pressure oil channel P for oil inlet and two return oil channels T1 and T2 for oil return. The ascending module 6 includes an electromagnetic ascending proportional valve 2 and a pressure compensation valve 1, which are installed as a single unit. One end of the ascending proportional valve 2 is connected to the pressure oil channel P, and the other end is connected to the actuation channel A for connecting the oil cylinder. A one-way valve module 4 is connected to the rear of the ascending proportional valve 2. The descending module 7 includes an electromagnetic descending proportional valve 3. The outlet end of the descending proportional valve 3 is connected to the return oil channel T2. An overflow valve module 5 is also installed in parallel with the descending proportional valve 3.

[0042] See Figures 1-13 As shown, the proportional riser valve 2 includes a proportional riser electromagnet 2010 with a manual operation button connected to the rear of the valve block. A pressure balancing pin 209 for the rising valve core is connected to the front end of the proportional riser electromagnet 2010. The pressure balancing pin 209 has external threads. A rising valve core positioning seat 207 is installed inside the valve block via a step. A stepped structure is also provided at the tail end of the pressure balancing pin 209, and a rising valve core spring 208 is installed at the front end of this step. The front end of the rising valve core spring 208 abuts against the rising valve core positioning seat 207, thus positioning the rising valve core. The front end of the seat 207 is provided with a rising valve core 206. A guide pin 205 is installed on the inner side of the front end of the rising valve core 206. Both the guide pin 205 and the rising valve core 206 have internal threads and are installed on the rising valve core pressure balance pin 209 through the threads. The pressure oil passage P inside the valve block is located at the front end of the rising valve core 206. The rising proportional valve outlet B is located on the outer side of the middle part of the rising valve core 206. The return oil passage T2 is located behind the rising proportional valve outlet B. The rising valve core pressure balance pin 209 has a small hole that connects its front head and outer tail end.

[0043] The pressure compensation valve 1 includes a positioning screw 204 inserted on the valve block. The top of the positioning screw 204 is located in the pressure oil passage P. A pressure compensation valve plug 201 is installed at the front end of the valve block. A pressure compensation valve core 203 is installed inside the pressure compensation valve plug 201, and a pressure compensation valve spring 202 is provided between the two. The rear end of the pressure compensation valve core 203 abuts against the positioning screw 204. A return oil passage T1 is located outside the pressure compensation valve core 203. A pressure feedback throttling orifice 8 is provided at the rear end of the pressure compensation valve core 203. The pressure feedback throttling orifice 8 is connected to the outlet B of the rising proportional valve.

[0044] The design is compact. The spring force of the pressure compensation valve spring 202 presses the pressure compensation valve core 203 to the right onto the positioning screw 204, disconnecting the pressure oil passage P from the return oil passage T1. The guide pin 205, the rising valve core 206, and the rising valve core pressure balance pin 209 form a moving module that moves together, driven by the rising proportional electromagnet 2010. When this moving module moves back and forth, the rising valve core positioning seat 207 remains stationary, while the small hole in the rising valve core pressure balance pin 209 ensures pressure balance on both sides. The guide pin 205 and the rising valve core 206 are threaded, allowing for adjustment of their installation position during installation, thereby adjusting the compression of the rising valve core spring 208. When the rising proportional electromagnet 2010 is not energized, the pressure oil passage P remains disconnected from the rising proportional valve outlet B, while the rising proportional valve outlet B remains connected to the return oil passage T2.

[0045] like Figure 2 As shown in the structure, when the proportional valve 2 is in the neutral position, the oil circuit is as follows: the proportional solenoid 2010 is not energized, the pressure oil in the pressure oil channel P pushes open the valve core 203 of the pressure compensation valve, and the hydraulic oil flows towards the return oil channel T1. Meanwhile, the pressure feedback throttle orifice 8, the outlet B of the proportional valve and the return oil channel T2 are connected. As the pressure in the spring chamber of the pressure compensation valve core 203 decreases until there is no pressure, the pressure in the pressure oil channel P is low.

[0046] Combination Figure 11When the proportional rise valve 2 rises, the proportional rise electromagnet 2010 is energized, and the push rod pushes the aforementioned motion module to move to the left, opening the passage between the pressure oil channel P and the outlet B of the proportional rise valve, as well as the oil passage between the outlet B of the proportional rise valve and the return oil passage T2. The pressure oil passes through the pressure oil channel P, through the outlet B of the proportional rise valve, and then through the check valve module 4, and then through the execution channel A of the valve block to reach the lower chamber of the cylinder, causing the cylinder to rise. At this time, the pressure feedback throttle orifice 8 is connected to the outlet B of the proportional rise valve, and the pressure at the outlet B of the proportional rise valve is fed back to the spring chamber of the pressure compensation valve core 203. When the pressure difference generated by the flow at the outlet B of the proportional rise valve is greater than the set pressure value of the pressure compensation valve spring 202, the pressure compensation valve core 203 will move to the left, opening the oil passage between the pressure oil channel P and the return oil passage T1, and discharging the excess pressure oil, thereby achieving adjustable cylinder rising speed. The proportional rise electromagnet 2010 has a manual button, which allows for manual operation even if an electrical fault causes the electromagnet to lose power.

[0047] See Figures 1-15 As shown, the proportional lowering valve 3 includes a proportional lowering solenoid 307 with a manual operation button installed on the rear side of the valve block. A lowering valve sleeve 306 is installed inside the valve block at the front end of the proportional lowering solenoid 307. A lowering valve core 305 that can slide within the lowering valve sleeve 306 is connected to the front end of the proportional lowering solenoid 307. The actuation channel A is connected to the outside of the lowering valve sleeve 306. The front end of the lowering valve core 305 is connected to the return oil channel T2. An oil groove is provided inside the lowering valve core 305, and its movement can be controlled by the oil groove. The control controls the opening and closing of the control channel A and the return oil channel T1, as well as the cross-sectional dimensions of the oil flow. A descent speed adjustment rod 302 is also threadedly installed on the valve block directly in front of the descent valve core 305. A spring support 303 is connected to the rear end of the descent speed adjustment rod 302. A descent spring 304 is provided between the spring support 303 and the descent valve core 305. A sealing nut 301 is also provided on the valve block at the opening where the descent speed adjustment rod 302 is installed. An internal hexagonal adjustment hole for adjustment is provided at the front end of the descent speed adjustment rod 302.

[0048] The descent speed adjusting rod 302 can be rotated through the adjusting hole at the front end, causing it to move along the thread. When the descent speed adjusting rod 302 is facing the rear end, i.e. Figure 14 In the middle, the greater the displacement to the right, the greater the compression of the descending spring 304 through the spring support 303, the smaller the opening of the descending valve core 305, and thus the smaller the descent speed of the cylinder.

[0049] When descent control is required, the descent proportional electromagnet 307 is energized, and the push rod pushes the descent spring 304 forward, opening the passage between the execution channel A and the return oil channel T2. The pressurized oil in the lower chamber of the cylinder can then flow to the return oil channel T2, and the cylinder begins to descend. During this process, the position of the descent valve core 305 determines the opening size, which in turn controls the oil flow rate. Therefore, the current of the descent proportional electromagnet 307 can control the descent speed of the cylinder, ensuring that the ratio is adjustable.

[0050] See Figures 1-8 As shown, the one-way valve module 4 includes a one-way valve plug 401 installed on the valve block. The one-way valve plug 401 is provided with a one-way valve core 403 inside, and a one-way valve spring 402 is provided between the two. The chamber at the front end of the one-way valve core 403 is connected to the execution channel A. The one-way valve core 403 has a hole that connects the execution channel A and the spring chamber where the one-way valve spring 402 is located.

[0051] The main function of the check valve is to maintain pressure. When both the rising proportional valve 2 and the falling proportional valve 3 are in the right position (that is, when the proportional control valve is in the neutral position), the pressure oil at the inlet of the check valve module 4 passes through the rising proportional valve 2 in the right position and is then sent to the return oil channel 2 T2. The check valve inlet is connected to the return oil, and the pressure in the lower chamber of the cylinder enters the check valve core 403 through the proportional control valve execution channel A, i.e., port A. Because of the cone sealing structure of the check valve core 403, zero leakage of the pressure oil in the lower chamber of the cylinder can be ensured, so that the cylinder can be stopped at any position when the proportional control valve is in the neutral position.

[0052] During operation, the one-way valve core 403 is pressed against the conical surface of the valve body by the one-way valve spring 402. The hole in the center of the one-way valve leads the pressure oil from port A to the spring chamber of the one-way valve, forming a reliable pressure oil action area. When the proportional control valve is in the neutral position, the one-way valve core 403, under the combined action of the pressure oil at port A (i.e., the lower chamber of the cylinder) and the one-way valve spring 402, forms a reliable sealing surface, ensuring that the leakage is basically zero and preventing the cylinder from automatically descending.

[0053] See Figures 1-10As shown, the overflow valve module 5 includes an overflow valve plug 501 mounted on the valve block. An overflow valve conical spring 502 is located inside the overflow valve plug 501. An overflow valve sub-module is located inside the overflow valve conical spring 502. The sub-module includes an overflow valve spring support 503 attached to the rear of the overflow valve conical spring 502. An overflow valve core 505 is mounted inside the overflow valve spring support 503. An overflow valve spring 504 is located between the outer side of the overflow valve core 505 and the overflow valve spring support 503. The rear end of the overflow valve core 505 is connected to the overflow valve sleeve 506 via a thread. The small overflow valve module is kept pressed against the conical surface of the valve body under the action of the overflow valve conical spring 502. The spring cavity where the overflow valve spring 504 is located is connected to the execution channel A through the connection port α opened in the valve block. The rear end of the overflow valve core 505 has a hexagonal center hole for controlling rotation. The part of the rod head of the overflow valve core 505 that extends out of the overflow valve spring support 503 is welded to the overflow valve spring support 503 to form the small overflow valve module.

[0054] The hexagonal center hole at the tail of the relief valve core 505 can be rotated with a wrench to adjust its front and rear position, thereby adjusting the compression of the relief valve spring 504. In use, when the pressure in the lower chamber of the oil cylinder exceeds the set pressure of the relief valve, the oil pressure can drive the relief valve core 505 to overcome the resistance of the relief valve spring 504 and move to the right, thereby opening the valve port to release pressure, protect the oil cylinder, and prevent overload.

[0055] It should be understood that the above-described specific embodiments of this utility model are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within the protection scope of this utility model. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A multi-purpose proportional control valve, comprising a valve block, characterized in that: The valve block is equipped with an ascending module (6) and a descending module (7). The valve block is provided with a pressure oil channel (P) for oil inlet and two return oil channels (T1 and T2) for oil return. The ascending module (6) includes an electromagnetic ascending proportional valve (2) and a pressure compensation valve (1), which are installed as a whole. One end of the ascending proportional valve (2) is connected to the pressure oil channel (P), and the other end is connected to the actuation channel (A) for connecting the oil cylinder. A check valve module (4) is connected behind the ascending proportional valve (2). The descending module (7) includes an electromagnetic descending proportional valve (3). The outlet end of the descending proportional valve (3) is connected to the return oil channel (T2). An overflow valve module (5) is also installed in parallel with the descending proportional valve (3).

2. The multi-purpose proportional control valve according to claim 1, characterized in that: The proportional riser valve (2) includes a proportional riser electromagnet (2010) with a manual operation button connected to the rear of the valve block. The front end of the proportional riser electromagnet (2010) is connected to a pressure balancing pin (209) for the valve core. The pressure balancing pin (209) for the valve core has an external thread. A valve core positioning seat (207) for the valve core is installed inside the valve block through a step. The tail end of the pressure balancing pin (209) for the valve core also has a stepped structure, and a valve core spring (208) for the valve core is set at the front end of the step. The front end of the valve core spring (208) abuts against the valve core positioning seat for the valve core. On (207), the front end of the rising valve core positioning seat (207) is provided with a rising valve core (206), and a guide pin (205) is installed on the inner side of the front end of the rising valve core (206). The guide pin (205) and the rising valve core (206) are both threaded and are installed on the pressure balance pin (209) of the rising valve core through the thread. The pressure oil passage (P) in the valve block is located at the front end of the rising valve core (206), and the rising proportional valve outlet (B) is located on the outer side of the middle part of the rising valve core (206). The return oil passage (T2) is located behind the rising proportional valve outlet (B).

3. A multi-purpose proportional control valve according to claim 2, characterized in that: The pressure compensation valve (1) includes a positioning screw (204) inserted on the valve block. The top of the positioning screw (204) is located in the pressure oil passage (P). A pressure compensation valve plug (201) is installed at the front end of the valve block. A pressure compensation valve core (203) is installed inside the pressure compensation valve plug (201). A pressure compensation valve spring (202) is provided between the two. The rear end of the pressure compensation valve core (203) abuts against the positioning screw (204). The return oil passage (T1) is located outside the pressure compensation valve core (203). A pressure feedback throttling hole (8) is provided at the rear end of the pressure compensation valve core (203). The pressure feedback throttling hole (8) is connected to the outlet (B) of the rising proportional valve.

4. A multi-purpose proportional control valve according to claim 1, characterized in that: The descending proportional valve (3) includes a descending proportional electromagnet (307) with a manual operation button installed on the rear side of the valve block. A descending valve sleeve (306) is installed inside the valve block at the front end of the descending proportional electromagnet (307). A descending valve core (305) that can slide inside the descending valve sleeve (306) is connected to the front end of the descending proportional electromagnet (307). An execution channel (A) is connected to the outside of the descending valve sleeve (306). The front end of the descending valve core (305) is connected to the return oil channel two (T2). An oil groove is provided inside the descending valve core (305). By moving it, the oil groove can control the opening and closing of the execution channel (A) and the return oil channel one (T1) and the cross-sectional size of the oil flow. A descending speed adjustment rod (302) is also installed on the valve block directly in front of the descending valve core (305) by thread. A spring support (303) is connected to the rear end of the descending speed adjustment rod (302). A descending spring (304) is provided between the spring support (303) and the descending valve core (305).

5. A multi-purpose proportional control valve according to claim 1, characterized in that: The one-way valve module (4) includes a one-way valve plug (401) installed on the valve block. The one-way valve plug (401) is provided with a one-way valve core (403) inside, and a one-way valve spring (402) is provided between the two. The chamber at the front end of the one-way valve core (403) is connected to the execution channel (A). The one-way valve core (403) has a hole that connects the execution channel (A) and the spring chamber where the one-way valve spring (402) is located.

6. A multi-purpose proportional control valve according to claim 1, characterized in that: The overflow valve module (5) includes an overflow valve plug (501) installed on the valve block. An overflow valve conical spring (502) is provided inside the overflow valve plug (501). An overflow valve small module is provided inside the overflow valve conical spring (502). The overflow valve small module includes an overflow valve spring support (503) attached to the rear of the overflow valve conical spring (502). An overflow valve core (505) is installed inside the overflow valve spring support (503). An overflow valve spring (504) is provided between the outer side of the overflow valve core (505) and the overflow valve spring support (503). An overflow valve sleeve (506) is connected to the rear end of the overflow valve core (505) by a thread. The spring cavity where the overflow valve spring (504) is located is connected to the execution channel (A) through the connection port (α) opened in the valve block.

7. A multi-purpose proportional control valve according to claim 2, characterized in that: The rising valve core pressure balancing pin (209) has a small hole connecting its front head and outer tail end.

8. A multi-purpose proportional control valve according to claim 6, characterized in that: The overflow valve core (505) has a hexagonal center hole at its rear end for controlling rotation.

9. A multi-purpose proportional control valve according to claim 4, characterized in that: A sealing nut (301) is also provided on the valve block at the opening where the descent speed adjusting rod (302) is installed, and an internal hexagonal adjustment hole for adjustment is provided at the front end of the descent speed adjusting rod (302).

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