CN117646640A - Hydraulic support electrohydraulic proportional control system and method based on independent pilot liquid supply valve - Google Patents

Abstract

The invention provides a hydraulic support electrohydraulic proportional control system and method based on an independent pilot liquid supply valve, and belongs to the technical field of hydraulic pressure. A proportional flow valve is respectively added at the inlet and outlet of the upright post jack and the pushing jack to control the movement of the hydraulic support, the proportional flow valve is connected in parallel at the outlet of the emulsion pump, the bypass controls the output flow of the emulsion pump, and the pilot valve of the flow valve is a proportional servo valve; the electromagnetic unloading valve on the emulsion pump station is replaced by the proportional unloading valve driven by the single-nozzle baffle valve, so that the proportional unloading of the system pressure is realized; a low-pressure low-flow emulsified oil system is added to independently supply liquid for a pilot valve of a flow valve and a nozzle baffle valve of a proportional unloading valve. The electro-hydraulic proportional control system of the support not only can accurately control the movement of the pushing jack and the upright jack and solve the problem of linear control of the fully mechanized mining face, but also can realize proportional control of the output flow and the pressure of the emulsion pump station, reduce pressure impact and improve the action speed of the support.

Description

Electro-hydraulic proportional control system and method for hydraulic support based on independent pilot liquid supply valve

Technical field

The invention belongs to the field of hydraulic technology, specifically an electro-hydraulic proportional control system and method for a hydraulic support based on an independent pilot liquid supply valve.

Background technique

Hydraulic supports are important support equipment for fully mechanized mining working faces. The intelligence of their electro-hydraulic control components and systems is of great significance to the high efficiency and safe production of working faces. The control valves of the hydraulic support, such as the reversing valve and the unloading valve, are switch-type components. The switch-type valve cannot achieve continuous control. At the moment of opening and closing, it will bring a huge hydraulic impact to the hydraulic support control system. This hydraulic impact It will cause equipment and pipelines to vibrate, generate noise, and damage seals. In addition, the switch-type reversing valve cannot achieve proportional control of the movement of the hydraulic support, resulting in the inability to guarantee the straightness of the fully mechanized mining working surface, and the inability to accurately control the shrinkage of the column jack. When the roof of the working surface is broken or pressed, it must be brought Pressure rack.

In addition, the hydraulic support has many actuators, including column jacks, push jacks, support jacks, lifting jacks and shielding beam jacks, etc. The real-time fluid demand of the hydraulic support changes greatly. Although the emulsion pump station of the hydraulic support adopts variable frequency control, due to the large inertia and slow response of the variable frequency pump, the infusion volume of the emulsion pump cannot be quickly adjusted to match the liquid demand of the stent actuator. When the output flow of the emulsion pump is much greater than the liquid demand of the stent actuator, the unloading valve is repeatedly loaded and unloaded, and the system pressure fluctuates violently; when the output flow of the emulsion pump is less than the liquid demand of the stent actuator, the system pressure If the landing is serious, the movement speed of the bracket will be reduced, which may easily lead to safety accidents.

Contents of the invention

In view of the shortcomings of the existing technology, an electro-hydraulic proportional control system and method for a hydraulic support based on an independent pilot supply valve is provided. In view of the problem that the support reversing valve and unloading valve cannot achieve continuous proportional control, an independent pilot supply valve is proposed. A high-pressure large-flow proportional unloading valve driven by a high-frequency response proportional flow valve and a single nozzle baffle valve in the liquid circuit; a proportional flow valve is added to the inlet and outlet of the column jack and push jack respectively to realize the movement of the column jack and push jack. Precise control; use the proportional unloading valve to replace the electromagnetic unloading valve on the emulsion pump station to realize proportional unloading of the emulsion pump station; add a low-pressure, low-flow emulsification line to the existing high-pressure and large-flow emulsion supply system Oil system, the emulsified oil system supplies liquid to the pilot valve of the flow valve and the nozzle flapper valve of the proportional unloading valve; in addition, the proposed proportional flow valve with independent pilot liquid supply can also be used to control the flow of the emulsion pump station of the hydraulic support. Control to achieve matching of supply and demand flow of hydraulic support actuator.

In order to achieve the above technical objectives, the present invention provides an electro-hydraulic proportional control system for a hydraulic support based on an independent pilot liquid supply valve, which is characterized in that it includes a high-pressure and large-flow emulsion liquid supply system, an electro-hydraulic reversing valve group, and a column jack. I. Column jack II and push jack; electro-hydraulic reversing valve group includes electro-hydraulic reversing valve a and electro-hydraulic reversing valve b;

On the basis of the emulsion liquid supply system, a low-pressure and low-flow emulsified oil system is added. The emulsified oil system includes an interconnected emulsified oil pump, a low-power motor and a relief valve;

Proportional flow valve II and one-way valve I are installed in parallel at the rod cavity inlet and outlet of column jack I and column jack II. Proportional flow valve III and single-way valve are installed in parallel at the rodless cavity inlet and outlet of column jack I and column jack II. Directional valve II, the other ends of the proportional flow valve II and the one-way valve I, the proportional flow valve III and the one-way valve II are all connected to the electro-hydraulic reversing valve a through pipelines; in the rod cavity of the push jack, the fluid flows in and out A proportional flow valve IV and a one-way valve III are arranged in parallel at the port, and a proportional flow valve V and a one-way valve IV are arranged in parallel at the inlet and outlet of the rodless cavity of the push jack. The proportional flow valve IV, the one-way valve III, and the proportional flow valve The other end of V and the one-way valve IV are connected to the electro-hydraulic reversing valve b through pipelines;

Set a proportional flow valve I on the outlet bypass of the emulsion pump I;

The proportional flow valve I, the proportional flow valve II, the proportional flow valve III, the proportional flow valve IV and the proportional flow valve V are all double liquid supply flow valves. The main valve controls the flow of the emulsion system, and the emulsified oil system is a pilot valve. Liquid supply, and thus the movement of the main valve.

Furthermore, the proportional flow valve I, proportional flow valve II, proportional flow valve III, proportional flow valve IV, and proportional flow valve V have the same structure, and all include a symmetrical cylinder main valve and a three-position four-way servo spool valve as a pilot valve.

Further, the symmetrical cylinder main valve includes a flow valve main valve sleeve. The flow valve main valve sleeve is provided with a pilot valve oil inlet connected to the three-position four-way servo slide valve. The flow valve main valve sleeve is provided with upper and lower valves. Through hole, the flow valve main valve core is provided in the through hole, the flow valve main valve sensor is provided at the top of the flow valve main valve core, and the flow valve main valve liquid inlet and flow valve are provided at the bottom of the through hole of the flow valve main valve sleeve. The liquid outlet of the main valve and the main valve core of the flow valve include an upper and lower conductive piston structure. The upper conductive piston structure of the main valve core of the flow valve divides the through hole from top to bottom into the upper chamber of the flow valve main valve and the flow valve. The main valve controls the upper chamber and the flow valve main valve controls the lower chamber. The three-position four-way servo slide valve is connected to the flow valve main valve control upper chamber and the flow valve main valve control lower chamber respectively through the flow channel, thereby controlling the flow valve main valve core. move.

Further, the low-pressure and small-flow emulsified oil enters the three-position four-way servo slide valve through the pilot valve inlet of the proportional flow valve. The emulsified oil then passes through the three-position four-way servo slide valve and drives the main spool of the flow valve to move, resulting in high pressure and large flow. The emulsion passes through the main valve inlet and outlet of the flow valve to push the hydraulic support cylinder to move or bypass to control the output flow of the emulsion pump. The emulsified oil discharged from the three-position four-way servo slide valve passes through the flow valve pilot The oil outlet flows back to the emulsified oil tank.

Furthermore, the main valve sleeve of the proportional flow valve is made of aluminum bronze, and the main valve core of the flow valve is made of Ph martensitic stainless steel.

Furthermore, the main valve inlet and outlet of the proportional flow valve II are respectively equipped with a pre-valve pressure sensor I and a post-valve pressure sensor I; the main valve inlet and outlet of the proportional flow valve III are respectively installed with a pre-valve pressure sensor II and a post-valve pressure sensor. II; the main valve inlet and outlet of the proportional flow valve III are respectively equipped with a pre-valve pressure sensor III and a post-valve pressure sensor III; the main valve inlet and outlet of the proportional flow valve V are respectively installed with a pre-valve pressure sensor IV and a post-valve pressure sensor. IV.

A control method for the electro-hydraulic proportional control system of a hydraulic support based on an independent pilot liquid supply valve. The proportional control method of the movement of the support is as follows:

First, according to the requirements of the coal mining process, the expected movement speed curve of the push jack or column jack is proposed, and the flow rate required for the movement is calculated based on the size of each cylinder;

Measurements were made using the pre-valve pressure sensor I, pre-valve pressure sensor II, pre-valve pressure sensor III, pre-valve pressure sensor IV and post-valve pressure sensor I, post-valve pressure sensor II, post-valve pressure sensor III, and post-valve pressure sensor IV respectively. The main valve inlet and outlet pressures of proportional flow valve II, proportional flow valve III, proportional flow valve IV, and proportional flow valve V;

According to the main valve port opening, pressure difference and output flow formula, calculate the opening of the main valve core of the flow valve of proportional flow valve II, proportional flow valve III, proportional flow valve IV and proportional flow valve V;

According to the opening requirements of the main spool of the flow valve, the movement of the three-position four-way servo slide valve is controlled, so that the emulsified oil enters the lower chamber controlled by the main valve from the pilot valve inlet through the three-position four-way servo slide valve, and the main valve controls the upper chamber. The emulsified oil flows back to the pilot outlet of the flow valve through the three-position four-way servo slide valve and flows back to the emulsified oil tank. The main spool of the proportional flow valve moves upward under the action of the pressure difference between the upper and lower chambers controlled by the main valve, and the lower part of the main spool is detached. The valve sleeve thus opens;

Judging from the speed curve of the cylinder, when the openings of proportional flow valve II, proportional flow valve III, proportional flow valve IV, and proportional flow valve V need to be reduced, the three-position four-way servo slide valve moves to allow the emulsified oil to enter from the pilot valve. The oil port enters the upper chamber controlled by the main valve through the three-position four-way servo slide valve. The emulsified oil in the lower chamber controlled by the main valve flows back to the flow valve pilot outlet through the three-position four-way servo slide valve and flows back to the emulsified oil tank. The proportional flow valve The main valve core moves downward under the pressure difference between the upper and lower chambers controlled by the main valve, and the opening of the main valve core decreases;

The main valve sensor of the flow valve measures the displacement of the main valve core in real time, sends it to the controller, and compares it with the calculated expected main valve displacement to control the main valve core displacement in a closed loop.

Further, the flow control method of the emulsion pump station is as follows:

The controller calculates the flow required by the oil cylinder in real time based on the current movement of the hydraulic support, determines the working quantity of the emulsion pump according to the flow demand, and uses the proportional flow valve I to adjust the output flow of the emulsion pump I;

Specifically: when the stent requires a small amount of liquid, only the emulsion pump I is turned on, the high-power variable frequency motor I of the emulsion pump I is operated at maximum speed, and the proportional flow valve I is used to control the actual output flow of the emulsion pump I; when only the emulsion pump I is used When the emulsion pump I cannot meet the emulsion flow requirement, the emulsion pump II set up in parallel with the emulsion pump I is started. At this time, the high-power variable frequency motor I and the high-power variable frequency motor II of the emulsion pump I and the emulsion pump II have the maximum Speed operation, use the proportional flow valve I to control the actual output flow of the emulsion pump I; when the flow is not enough, another set of emulsion pumps is opened; when the liquid demand of the bracket decreases, the emulsion pumps are closed one by one.

A proportional unloading valve used in the electro-hydraulic proportional control system of a hydraulic support based on an independent pilot liquid supply valve. The proportional unloading valve is a double liquid supply valve and is used to replace the electromagnetic valve used in a high-pressure and large-flow emulsion pump station. Unloading valve; the main valve of the proportional unloading valve proportionally controls the pressure of the emulsion system, and the emulsified oil system provides emulsified oil to the pilot valve of the proportional unloading valve, thereby controlling the movement of the main valve core;

Specifically, it includes an unloading valve check valve, an unloading valve main valve and an unloading valve pilot valve that are connected to each other, wherein the unloading valve check valve and the unloading valve main valve are arranged in the unloading valve housing;

The unloading valve housing is provided with left and right through holes. The unloading valve check valve is located on the left side of the through hole of the unloading valve housing. The unloading valve main valve is located on the right side of the through hole of the unloading valve housing. , the unloading valve check valve and the unloading valve main valve liquid inlet are set opposite each other with a cavity between them. The cavity is equipped with an unloading valve main valve liquid inlet on the side of the unloading valve shell. The liquid outlet of the check valve is provided with an unloading valve check valve liquid outlet on the unloading valve housing, and the liquid outlet of the unloading valve main valve is provided with an unloading valve main valve on the unloading valve housing. The liquid return port of the unloading valve main valve is connected to the liquid return hole of the unloading valve pilot valve;

The unloading valve pilot valve includes an unloading valve pilot valve poppet valve assembly and an unloading valve pilot valve single nozzle baffle valve assembly that are connected to each other. The unloading valve pilot valve single nozzle baffle valve assembly is respectively provided with an unloading valve nozzle. Damper valve oil outlet and unloading valve nozzle damper valve oil inlet;

The unloading valve one-way valve includes an unloading valve one-way valve sleeve. The end of the unloading valve one-way valve sleeve is equipped with an unloading valve one-way valve screw plug for blocking. The unloading valve one-way valve sleeve has a There is an unloading valve one-way valve spool, and there is an unloading valve one-way valve spring between the unloading valve one-way valve spool and the unloading valve one-way valve screw plug; the unloading valve one-way valve end and side wall Opening, the unloading valve check valve spool moves to control the connection and shutdown between the end and the side wall opening;

The unloading valve main valve includes an unloading valve main valve sleeve. The unloading valve main valve sleeve is equipped with an unloading valve main valve cover. The unloading valve main valve sleeve is equipped with an unloading valve main valve core. There is an unloading valve main spring between the unloading valve main valve core and the unloading valve main valve bonnet. The end and side wall opening of the unloading valve main valve sleeve are controlled by the movement of the unloading valve main valve core. The main valve core of the unloading valve has a through hole at the end, and the main valve cover of the unloading valve has a through hole connected to the main valve core of the unloading valve. Valve bonnet through hole;

The unloading valve pilot valve poppet assembly includes an unloading valve pilot valve housing. The unloading valve pilot valve housing is a cylindrical structure with one end sealed and one end open. The open end of the unloading valve pilot valve housing is provided with a sealing unloading valve. The unloading valve pilot valve screw is plugged. The unloading valve pilot valve housing is provided with a cavity space. In the cavity space, there is an unloading valve pilot valve spool with a tapered structure at the end and a matching unloading valve pilot valve spool. The valve seat, the unloading valve pilot valve oil inlet chamber is formed between the valve seat and the unloading valve pilot valve plug. The unloading valve pilot valve oil inlet chamber is connected to the unloading valve pilot valve liquid inlet hole. The unloading valve pilot valve valve The tail of the core is connected to the unloading valve pilot valve spring control piston through the unloading valve pilot valve spring. A spring cavity is formed between the unloading valve pilot valve spring control piston and the valve seat. There is a hole on the plug valve seat that can be controlled by the unloading valve pilot. The valve core controls the unloading valve pilot valve damping hole that connects the unloading valve pilot valve oil inlet chamber and the spring chamber. The spring chamber is connected to the unloading valve pilot valve return liquid hole. The unloading valve pilot valve spring controls the piston and the unloading valve. An unloading valve pilot valve control chamber is formed between the sealing sections of the pilot valve housing. The unloading valve pilot valve control chamber is connected to the unloading valve pilot valve control chamber oil inlet. The bottom of the unloading valve pilot valve spring control piston is provided with a protrusion. , to prevent the unloading valve pilot valve control cavity oil inlet from being blocked;

The unloading valve pilot valve single nozzle flapper valve assembly includes an unloading valve nozzle valve housing. The lower part of the unloading valve nozzle valve housing is provided with a left-right through hole. The left side of the through hole allows oil to enter through the unloading valve nozzle valve. The hole is connected to the oil inlet of the unloading valve nozzle damper valve, and the right side of the through hole is connected to the oil outlet of the unloading valve nozzle damper valve through the oil return port of the unloading valve nozzle valve and the oil outlet of the unloading valve nozzle damper valve. There is a through hole that can be controlled according to the control signal. The baffle movement assembly includes a lower magnet and an upper magnet. There is an armature between the lower magnet and the upper magnet. There is a spring tube vertically in the middle of the armature. There is a baffle inside the spring tube that blocks the through hole. There is a coil wound around the armature. It is located in the through hole on the left side of the baffle and has an unloading valve nozzle pointing to the right through the unloading valve nozzle valve group screw plug. The unloading valve nozzle valve oil inlet is damped by the unloading valve nozzle valve. The hole is connected to the unloading valve nozzle, a cavity is provided between the unloading valve nozzle valve damping hole and the unloading valve nozzle, and the cavity is connected to the unloading valve nozzle baffle valve control connection hole;

The emulsified oil with low pressure and small flow enters the unloading valve pilot valve single nozzle baffle valve assembly through the oil inlet of the unloading valve nozzle baffle valve. The emulsified oil sprayed from the unloading valve nozzle flows back through the return hole of the unloading valve pilot valve. Emulsified oil tank.

Further, the working method of the proportional unloading valve is as follows:

When the pressure of the support hydraulic system is higher than the unloading pressure of the unloading valve, the unloading valve pilot valve acts, causing the baffle to move in the direction away from the unloading valve nozzle, so that the emulsion is drained from the unloading valve nozzle valve return port, causing the The pressure in the control chamber of the unloading valve pilot valve gradually decreases. The unloading valve pilot valve core gradually separates from the valve seat and opens. The pressure in the upper chamber of the unloading valve main valve core gradually decreases. The unloading valve main valve core is slowly opened, and the unloading valve main valve core is slowly opened. The end opening of the main valve sleeve of the load valve is connected to the openings on both sides to achieve gradual proportional unloading;

When the actuator of the hydraulic support continues to operate or the system leaks and the system pressure is lower than the loading pressure, the baffle gradually moves toward the nozzle, and the pressure in the control chamber of the unloading valve pilot valve gradually rises, and the unloading valve pilot valve The valve core gradually closes, the pressure in the upper chamber of the unloading valve main valve core rises, the unloading valve main valve slowly closes, the unloading valve check valve opens, and the system pressure gradually increases in proportion to the proportional unloading valve unloading pressure.

Beneficial effects of the present invention:

1) A high-pressure, large-flow, high-frequency response proportional flow valve with independent pilot liquid supply is proposed. The main valve of the flow valve adopts a symmetrical cylinder poppet valve structure, which can seal well in emulsion media; the valve sleeve is made of aluminum bronze. The valve core and shell are made of 17-4PH stainless steel, which can effectively resist corrosion. In order to improve the response frequency of the flow valve, the pilot valve of the flow valve adopts the structure of a three-position four-way slide valve; a double liquid supply flow valve and a one-way valve are respectively installed at the inlet and outlet of the column jack and push jack, and the proportional control column jack and Push the movement of the jack; connect a dual liquid supply flow valve system in parallel at the oil outlet of the emulsion pump to adjust the output flow of the emulsion pump, solving the problem of the slow response speed of the current underground variable frequency pump that cannot achieve rapid adjustment of the liquid supply flow.

2) Pressure sensors are installed at the inlet and outlet of the flow valve respectively to calculate the pressure difference between the inlet and outlet of the flow valve, and according to the relationship between the valve core opening - pressure difference and output flow, the displacement of the main valve is adjusted in real time to accurately control the column jack and movement. The movement of the jack.

3) A high-frequency response proportional unloading valve driven by a nozzle damper valve is proposed. The pilot valve of the unloading valve is driven by the nozzle damper valve. By controlling the compression force of the spring of the pilot valve, the system pressure is controlled, which has It has the characteristics of large output force and fast response speed. The proportional unloading valve is used to replace the electromagnetic unloading valve on the original system, which reduces the system pressure impact and improves the service life of the electro-hydraulic components of the hydraulic support.

4) Based on the original emulsion liquid supply system, a low-pressure and small-flow emulsified oil system is connected in parallel to provide emulsified oil medium for the pilot valve of the proposed proportional flow valve and the nozzle damper valve of the proportional unloading valve.

Description of drawings

Figure 1 is a hydraulic principle diagram of the electro-hydraulic proportional control system of a hydraulic support based on an independent pilot liquid supply valve according to the present invention;

Figure 2 is a schematic diagram of a proportional unloading valve driven by a single nozzle flapper valve according to the present invention;

Figure 3 is a hydraulic schematic diagram of a proportional unloading valve driven by a single nozzle flapper valve according to the present invention;

Figure 4 is a schematic structural diagram of the unloading valve check valve of the proportional unloading valve of the present invention;

Figure 5 is a schematic diagram of the main valve assembly of the proportional unloading valve of the present invention;

Figure 6 is a schematic diagram of the pilot valve assembly of the proportional unloading valve of the present invention;

Figure 7 is a schematic diagram of the pilot poppet valve assembly of the proportional unloading valve of the present invention;

Figure 8 is a schematic diagram of the pilot driven single nozzle flapper valve assembly of the proportional unloading valve of the present invention;

Figure 9 is a schematic structural diagram of a high-pressure, large-flow, high-frequency response proportional flow valve of the present invention;

Figure 10 is a hydraulic schematic diagram of a high-pressure, large-flow, high-frequency response proportional flow valve of the present invention;

In the picture: 1. Emulsified oil pump; 2. Low-power motor; 3. Overflow valve; 4. Emulsion pump I; 5. High-power variable frequency motor I; 6. Emulsion pump II; 7. High-power variable frequency motor II; 8. Unloading valve pressure sensor; 9. Proportional unloading valve; 10-1. Proportional flow valve I; 10-2. Proportional flow valve II; 10-3. Proportional flow valve III; 10-4. Proportional flow valve IV ;10-5. Proportional flow valve V; 11. Electro-hydraulic reversing valve group; 12-1. Pre-valve pressure sensor I; 12-2. Pre-valve pressure sensor II; 12-3. Pre-valve pressure sensor III; 12 -4. Pressure sensor IV in front of the valve; 13-1, one-way valve I; 13-2, one-way valve II; 13-3, one-way valve III; 13-4, one-way valve IV; 14-1, valve Rear pressure sensor I; 14-2, rear pressure sensor II; 14-3, rear pressure sensor III; 14-4, rear pressure sensor IV; 15-1 column jack I; 15-2 column jack II; 16 , push jack;

9-1. Unloading valve check valve; 9-11. Unloading valve check valve sleeve; 9-12. Unloading valve check valve core; 9-13. Unloading valve check valve spring; 9 -14. Unloading valve check valve screw plug; 9-2. Unloading valve main valve liquid inlet; 9-3. Unloading valve main valve; 9-4. Unloading valve housing; 9-5. Unloading Unloading valve pilot valve; 9-6. Unloading valve nozzle baffle valve oil outlet; 9-7. Unloading valve nozzle baffle valve oil inlet; 9-8. Unloading valve pilot valve return hole; 9- 9. Liquid return port of the main valve of the unloading valve; 9-10. Liquid outlet of the one-way valve of the unloading valve; 9-31. Main valve sleeve of the unloading valve; 9-32. Main valve core of the unloading valve; 9- 33. Unloading valve main valve spring; 9-04. Unloading valve main valve bonnet; 9-35. Unloading valve main valve bonnet through hole; 9-51. Unloading valve pilot valve poppet valve assembly; 9- 5101. Unloading valve pilot valve control chamber oil inlet; 9-5102. Unloading valve pilot valve control chamber; 9-5103. Unloading valve pilot valve spring control piston; 9-5104. Unloading valve pilot valve spring; 9 -5105. Unloading valve pilot valve spool; 9-5106. Unloading valve pilot valve damping hole; 9-5107. Unloading valve pilot valve oil inlet chamber; 9-5108. Unloading valve pilot valve screw plug; 9- 5109. Unloading valve pilot valve housing; 9-5110. Unloading valve pilot valve liquid inlet hole; 9-5111. Unloading valve pilot valve liquid return hole;

9-52. Unloading valve pilot valve single nozzle flapper valve assembly; 9-5201, lower conductor magnet; 9-5202, armature; 9-5203, upper conductor magnet; 9-5204, coil; 9-5205, spring tube ; 9-5206, baffle; 9-5207, unloading valve nozzle valve housing; 9-5208, unloading valve nozzle valve oil inlet hole; 9-5209, unloading valve nozzle valve damping hole; 9-5210, unloading valve Loading valve nozzle baffle valve control connection hole; 9-5211, unloading valve nozzle valve spray group screw plug; 9-5212, unloading valve nozzle; 9-5213, unloading valve nozzle valve oil return port;

10-101, flow valve main valve liquid inlet; 10-102, flow valve main valve liquid outlet; 10-103, flow valve main valve sleeve; 10-104, flow valve pilot valve oil inlet; 10-105, Flow valve main valve core; 10-106, flow valve main valve sensor; 10-107, flow valve main valve upper chamber; 10-108, three-position four-way servo slide valve; 10-109, flow valve main valve control upper chamber ; 10-110. The main valve of the flow valve controls the lower chamber; 10-111. The oil outlet of the pilot valve of the flow valve.

Detailed ways

The embodiments of the present invention will be further described below in conjunction with the accompanying drawings:

As shown in Figure 1, an electro-hydraulic proportional control system for a hydraulic support based on an independent pilot liquid supply valve of the present invention includes a high-pressure and large-flow emulsion liquid supply system, an electro-hydraulic reversing valve group 11, and a column jack I15-1 , column jack II15-2 and push jack 16; the electro-hydraulic reversing valve group 11 includes electro-hydraulic reversing valve a and electro-hydraulic reversing valve b;

On the basis of the high-pressure and large-flow emulsion liquid supply system, a low-pressure and small-flow emulsified oil system is added. The emulsified oil system includes an interconnected emulsified oil pump 1, a low-power motor 2, and a relief valve 3;

Proportional flow valve II10-2 and one-way valve I13-1 are installed in parallel at the rod cavity inlet and outlet of column jack I15-1 and column jack II15-2, and in the rodless pipes of column jack I15-1 and column jack II15-2 The cavity inlet and outlet are provided with a proportional flow valve III10-3 and a one-way valve II13-2 in parallel. The proportional flow valve II10-2 and the one-way valve I13-1, the proportional flow valve III10-3 and the one-way valve II13-2 are The other end is connected to the electro-hydraulic reversing valve a through pipelines; the proportional flow valve IV10-4 and the one-way valve III13-3 are arranged in parallel at the inlet and outlet of the rod cavity of the push jack 16, and in the rodless cavity of the push jack 16 The proportional flow valve V10-5 and the one-way valve IV13-4 are arranged in parallel at the inlet and outlet. The proportional flow valve IV10-4 and the one-way valve III13-3, the proportional flow valve V10-5 and the one-way valve IV13-4 are The other end is connected to the electro-hydraulic reversing valve b through a pipeline;

Set proportional flow valve I10-1 on the outlet bypass of emulsion pump I;

The proportional flow valve I10-1, proportional flow valve II10-2, proportional flow valve III10-3, proportional flow valve IV10-4 and proportional flow valve V10-5 are all double liquid supply flow valves, and their main valve controls the emulsion. The flow rate of the system, the emulsified oil system supplies liquid to the pilot valve, and then the movement of the main valve.

The electromagnetic unloading valve on the high-pressure and large-flow emulsion pump station is replaced with a proportional unloading valve 9; the proportional unloading valve 9 is a double liquid supply valve, and its main valve proportionally controls the pressure of the emulsion system, and the emulsified oil system is The pilot valve of the proportional unloading valve 9 provides emulsified oil, thereby controlling the movement of the main valve core.

As shown in Figure 2-8, the proportional flow valve I10-1, proportional flow valve II10-2, proportional flow valve III10-3, proportional flow valve IV10-4, and proportional flow valve V10-5 have the same structure and all include symmetrical cylinders. type main valve and a three-position four-way servo slide valve 10-108 as a pilot valve. The symmetrical cylinder main valve includes a flow valve main valve sleeve 10-103. The flow valve main valve sleeve 10-103 has a pilot valve oil inlet 10-104 that communicates with the three-position four-way servo slide valve 10-108. The main valve sleeve 10-103 is provided with through holes arranged up and down. A flow valve main valve core 10-105 is provided in the through hole. A flow valve main valve sensor 10-106 is provided on the top of the flow valve main valve core 10-105. , the bottom of the through hole of the flow valve main valve sleeve 10-103 is provided with a flow valve main valve liquid inlet 10-101 and a flow valve main valve liquid outlet 10-102. The flow valve main valve core 10-105 includes an upper and lower guide section. Through the piston structure, the upper through-piston structure of the flow valve main valve core 10-105 divides the through hole from top to bottom into the flow valve main valve upper chamber 10-107, the flow valve main valve control upper chamber 10-109 and the flow The valve main valve controls the lower chamber 10-110, and the three-position four-way servo slide valve 10-108 is connected to the flow valve main valve control upper chamber 10-109 and the flow valve main valve control lower chamber 10-110 respectively through the flow channel, thereby controlling The flow valve main spool 10-105 moves. The main valve sleeve 10-103 of the proportional flow valve is made of aluminum bronze, and the main valve core 10-105 of the flow valve is made of 17-4Ph martensitic stainless steel.

The low-pressure and small-flow emulsified oil enters the three-position four-way servo slide valve 10-108 through the pilot valve inlet 10-104 of the proportional flow valve. The emulsified oil then passes through the three-position four-way servo slide valve 10-108 and drives the main flow valve. The valve core 10-105 moves, and the high-pressure and large-flow emulsion passes through the flow valve main valve inlet 10-101 and the flow valve main valve outlet 10-102 to push the hydraulic support cylinder to move or bypass the output flow of the emulsion pump. , the emulsified oil discharged from the three-position four-way servo slide valve 10-108 flows back to the emulsified oil tank through the pilot outlet port 10-111 of the flow valve.

The main valve inlet and outlet of the proportional flow valve II10-2 are respectively equipped with a pre-valve pressure sensor I12-1 and a post-valve pressure sensor I14-1; the main valve inlet and outlet of the proportional flow valve III10-3 are respectively equipped with a pre-valve pressure sensor. II12-2 and post-valve pressure sensor II14-2; the main valve inlet and outlet of the proportional flow valve III10-4 are respectively equipped with a pre-valve pressure sensor III12-3 and a post-valve pressure sensor III14-3; the proportional flow valve V10-5 The inlet and outlet of the main valve are respectively equipped with a pressure sensor IV12-4 in front of the valve and a pressure sensor IV14-4 in the back of the valve.

A control method for the electro-hydraulic proportional control system of a hydraulic support based on an independent pilot liquid supply valve. The support motion proportional control method is as follows:

First, according to the requirements of the coal mining process, the expected movement speed curve of the push jack or column jack is proposed, and the flow rate required for the movement is calculated based on the size of each cylinder;

Use the pre-valve pressure sensor I12-1, the pre-valve pressure sensor II12-2, the pre-valve pressure sensor III12-3, the pre-valve pressure sensor IV12-4 and the post-valve pressure sensor I14-1, post-valve pressure sensor II14-2, respectively. The post-valve pressure sensor III14-3 and the post-valve pressure sensor IV14-4 measure the main valve inlet and outlet pressures of the proportional flow valve II10-2, the proportional flow valve III10-3, the proportional flow valve IV10-4, and the proportional flow valve V10-5;

According to the main valve port opening, pressure difference and output flow formula, calculate the flow valve main valve of proportional flow valve II10-2, proportional flow valve III10-3, proportional flow valve IV10-4, proportional flow valve V10-5 Core 10-105 opening size;

According to the opening requirements of the flow valve main spool 10-105, the movement of the three-position four-way servo slide valve 10-108 is controlled, so that the emulsified oil passes from the pilot valve inlet 10-104 through the three-position four-way servo slide valve 10-108 The emulsified oil entering the lower chamber 10-110 controlled by the main valve and the upper chamber 10-109 controlled by the main valve flows back to the flow valve pilot outlet 10-111 through the three-position four-way servo slide valve 10-108 and flows back to the emulsified oil tank, with a proportional flow rate The main valve core 10-105 of the valve moves upward under the pressure difference between the upper and lower chambers controlled by the main valve, and the lower part of the main valve core 10-105 breaks away from the valve sleeve and opens;

Judging from the speed curve of the cylinder, when the opening of the proportional flow valve II10-2, proportional flow valve III10-3, proportional flow valve IV10-4, and proportional flow valve V10-5 needs to be reduced, the three-position four-way servo slide valve 10 -108 moves, causing the emulsified oil to enter the main valve control upper chamber 10-110 from the pilot valve inlet 10-104 through the three-position four-way servo slide valve 10-108. The emulsified oil in the main valve control lower chamber 10-109 passes through the three The four-way servo slide valve 10-108 flows back to the pilot outlet port 10-111 of the flow valve back to the emulsified oil tank. The main spool 10-105 of the proportional flow valve moves downward under the action of the pressure difference between the upper and lower chambers controlled by the main valve. The opening of valve core 10-105 decreases;

The flow valve main valve sensor 10-106 measures the displacement of the main valve core 10-105 in real time, sends it to the controller, and compares it with the calculated expected main valve displacement to control the main valve core displacement in a closed loop.

The flow control method of the emulsion pump station is as follows:

The controller calculates the flow required by the cylinder in real time based on the current movement of the hydraulic support, determines the working quantity of the emulsion pump according to the flow demand, and uses the proportional flow valve I10-1 to adjust the output flow of the emulsion pump I4;

Specifically: when the stent requires a small amount of liquid, only the emulsion pump I4 is turned on, the high-power variable frequency motor I5 of the emulsion pump I4 runs at maximum speed, and the proportional flow valve I10-1 is used to control the actual output flow of the emulsion pump I4; when When the emulsion pump I4 alone cannot meet the emulsion flow requirement, the emulsion pump II6 set up in parallel with the emulsion pump I4 is started. At this time, the high-power variable frequency motor I5 and the high-power variable frequency motor of the emulsion pump I4 and the emulsion pump II6 are started. II7 operates at maximum speed, and uses proportional flow valve I10-1 to control the actual output flow of emulsion pump I4; when the flow is not enough, another set of emulsion pumps is opened; when the liquid demand of the bracket decreases, each emulsion pump is closed one by one. Emulsion pump.

As shown in Figures 9 and 10, a proportional unloading valve driven by a single nozzle flapper valve is a double liquid supply valve, used to replace the electromagnetic unloading valve used in high-pressure and large-flow emulsion pump stations; proportional unloading valve The main valve of the unloading valve 9 proportionally controls the pressure of the emulsion system, and the emulsified oil system provides emulsified oil to the pilot valve of the proportional unloading valve 9, thereby controlling the movement of the main valve core;

It includes interconnected unloading valve check valve 9-1, unloading valve main valve 9-3 and unloading valve pilot valve 9-5, in which the unloading valve check valve 9-1, unloading valve main valve 9- 3 is set in the unloading valve housing 9-4;

The unloading valve housing 9-4 is provided with left and right through holes, the unloading valve check valve 9-1 is arranged on the left side of the through hole of the unloading valve housing 9-4, and the unloading valve main valve 9- 3 is set on the right side of the through hole of the unloading valve housing 9-4. The unloading valve one-way valve 9-1 and the unloading valve main valve 9-3 liquid inlets are set opposite each other with cavities left between them. The cavity is provided with an unloading valve main valve liquid inlet 9-2 on the side of the unloading valve housing 9-4, and the liquid outlet of the unloading valve check valve 9-1 is provided on the unloading valve housing 9-4. There is an unloading valve one-way valve liquid outlet 9-10. The liquid outlet of the unloading valve main valve 9-3 is provided with an unloading valve main valve liquid return port 9-9 on the unloading valve housing 9-4. The unloading valve main valve liquid return port 9-9 is connected to the unloading valve pilot valve liquid return hole 9-8;

The unloading valve pilot valve 9-5 includes an unloading valve pilot valve poppet valve assembly 9-51 and an unloading valve pilot valve single nozzle baffle valve assembly 9-52 that are connected to each other. The unloading valve pilot valve single nozzle baffle valve The assembly 9-52 is respectively provided with an unloading valve nozzle baffle valve oil outlet 9-6 and an unloading valve nozzle baffle valve oil inlet 9-7;

The unloading valve one-way valve 9-1 includes an unloading valve one-way valve sleeve 9-11. The tail of the unloading valve one-way valve sleeve 9-11 is provided with an unloading valve one-way valve screw plug 9-1 for blocking. 14. The unloading valve one-way valve valve sleeve 9-11 is equipped with the unloading valve one-way valve spool 9-12, the unloading valve one-way valve spool 9-12 and the unloading valve one-way valve screw plug 9- There is an unloading valve one-way valve spring 9-13 between 14; the unloading valve one-way valve 9-1 has an end and side wall opening, and the unloading valve one-way valve spool 9-12 moves to control the end and Turning on and off side wall openings;

The unloading valve main valve 9-3 includes an unloading valve main valve sleeve 9-31. The tail of the unloading valve main valve sleeve 9-31 is provided with an unloading valve main valve bonnet 9-34. The unloading valve main valve valve is The sleeve 9-31 is provided with an unloading valve main spool 9-32, and an unloading valve main spring 9-33 is arranged between the unloading valve main spool 9-32 and the unloading valve main valve cover 9-34. The end and side wall opening of the unloading valve main valve sleeve 9-31 are moved by the unloading valve main valve core 9-32 to control the conduction and shutoff of the end and the side wall opening; among them, the unloading valve main valve The core 9-32 has a through hole at its end, and the unloading valve main valve bonnet 9-34 has a through hole 9-35 in the unloading valve main valve bonnet that is connected to the unloading valve main valve core 9-32 through hole. ;

The unloading valve pilot valve poppet assembly 9-51 includes an unloading valve pilot valve housing 9-5109. The unloading valve pilot valve housing 9-5109 is a cylindrical structure with one end sealed and one end open. The unloading valve pilot valve housing 9-5109 The open end of 9-5109 is provided with a sealing unloading valve pilot valve screw plug 9-5108. The unloading valve pilot valve housing 9-5109 is provided with a cavity space, and the end of the cavity space is tapered. The structure of the unloading valve pilot valve spool 9-5105 and the valve seat matching the unloading valve pilot valve spool 9-5105, the unloading valve pilot valve inlet is formed between the valve seat and the unloading valve pilot valve screw plug 9-5108 The oil chamber 9-5107, the unloading valve pilot valve oil inlet chamber 9-5107 is connected to the unloading valve pilot valve liquid inlet hole 9-5110, and the tail of the unloading valve pilot valve spool 9-5105 passes through the unloading valve pilot valve spring 9 -5104 is connected to the unloading valve pilot valve spring control piston 9-5103. A spring cavity is formed between the unloading valve pilot valve spring control piston 9-5103 and the valve seat. The plug valve seat has a hole that can be used according to the unloading valve pilot valve. The spool 9-5105 controls the conduction of the unloading valve pilot valve oil inlet chamber 9-5107 and the unloading valve pilot valve damping hole 9-5106 of the spring chamber. The spring chamber is connected to the unloading valve pilot valve liquid return hole 9-5111. The unloading valve pilot valve control chamber 9-5102 is formed between the unloading valve pilot valve spring control piston 9-5103 and the unloading valve pilot valve housing 9-5109 sealing section. The unloading valve pilot valve control chamber 9-5102 is connected with the unloading valve. The unloading valve pilot valve control chamber oil inlet 9-5101, the unloading valve pilot valve spring control piston 9-5103 is provided with a protrusion at the bottom to prevent the unloading valve pilot valve control chamber oil inlet 9-5101 from being blocked;

The unloading valve pilot valve single nozzle flapper valve assembly 9-52 includes an unloading valve nozzle valve housing 9-5207. The lower part of the unloading valve nozzle valve housing 9-5207 is provided with left and right through holes. The left side is connected to the unloading valve nozzle damper valve oil inlet 9-7 through the unloading valve nozzle valve oil inlet 9-5208, and the right side of the through hole is connected to the unloading valve through the unloading valve nozzle valve oil return port 9-5213 The nozzle damper valve oil outlet 9-6 is connected, and the through hole is provided with a component that can control the baffle movement according to the control signal. The component includes a lower magnet 9-5201 and an upper magnet 9-5203. The lower magnet 9- There is an armature 9-5202 between 5201 and the upper magnet 9-5203. There is a spring tube 9-5205 vertically in the middle of the armature 9-5202. There is a baffle 9-5206 inside the spring tube 9-5205 that blocks the through hole. The armature There is a coil 9-5204 wound around 9-5202, which is located in the through hole on the left side of the baffle 9-5206. Through the unloading valve nozzle, the valve spray group screw plug 9-5211 is provided with an unloading valve nozzle 9-5212 pointing to the right. The oil inlet hole 9-5208 of the unloading valve nozzle valve is connected to the unloading valve nozzle 9-5212 through the unloading valve nozzle valve damping hole 9-5209, and the unloading valve nozzle valve damping hole 9-5209 is connected to the unloading valve nozzle 9-5212. There is a cavity between them, and the cavity is connected to the unloading valve, nozzle, baffle valve control connection hole 9-5210;

The emulsified oil with low pressure and small flow enters the unloading valve pilot valve single nozzle baffle valve assembly 9-52 through the oil inlet 9-7 of the unloading valve nozzle baffle valve. The emulsified oil sprayed from the unloading valve nozzle 9-5212 is unloaded through The liquid return hole 9-8 of the load valve pilot valve flows back to the emulsified oil tank.

The working method of the proportional unloading valve 9 is as follows:

When the pressure of the support hydraulic system is higher than the unloading pressure of the unloading valve, the unloading valve pilot valve 9-5 acts, causing the baffle 9-5206 to move away from the unloading valve nozzle 9-5212, causing the emulsion to flow from the unloading valve The oil return port 9-5213 of the nozzle valve is drained away, causing the pressure in the control chamber 9-5102 of the unloading valve pilot valve to gradually decrease. The unloading valve pilot valve core 9-5105 gradually separates from the valve seat and opens, and the unloading valve main valve core The pressure in the upper chamber of 9-32 gradually decreases, the main valve core of the unloading valve 9-32 is slowly opened, and the end opening of the main valve sleeve 9-31 of the unloading valve is connected with the openings on both sides to achieve gradual proportional unloading;

When the actuator of the hydraulic support continues to operate or the system leaks and the system pressure is lower than the loading pressure, the baffle 9-5206 gradually moves toward the nozzle 9-5212, and the unloading valve pilot valve controls the cavity 9-5102. The pressure gradually rises, the unloading valve pilot valve core 9-5105 gradually closes, the pressure in the upper chamber of the unloading valve main valve core 9-32 rises, the unloading valve main valve 9-32 slowly closes, and the unloading valve check valve 9- 1 opens, the system pressure gradually increases in proportion to the proportional unloading valve 9 unloading pressure.

Claims (10)

1. An electro-hydraulic proportional control system for a hydraulic support based on an independent pilot liquid supply valve, which is characterized in that it includes a high-pressure and large-flow emulsion liquid supply system, an electro-hydraulic reversing valve group (11), and a column jack I (15- 1), column jack II (15-2) and push jack (16); the electro-hydraulic reversing valve group (11) includes electro-hydraulic reversing valve a and electro-hydraulic reversing valve b; On the basis of the emulsion liquid supply system, a low-pressure and low-flow emulsified oil system is added. The emulsified oil system includes an interconnected emulsified oil pump (1), a low-power motor (2) and a relief valve (3); Proportional flow valve II (10-2) and one-way valve I (13-1) are installed in parallel at the rod chamber inlet and outlet of column jack I (15-1) and column jack II (15-2). The proportional flow valve III (10-3) and the one-way valve II (13-2) are arranged in parallel at the rodless chamber inlet and outlet of I (15-1) and column jack II (15-2). The proportional flow valve II (10-2) and the other end of check valve I (13-1), proportional flow valve III (10-3) and check valve II (13-2) are all connected to the electro-hydraulic reversing valve a through pipelines ; The proportional flow valve IV (10-4) and the one-way valve III (13-3) are installed in parallel at the rod cavity inlet and outlet of the push jack (16), and the rodless cavity inlet and outlet of the push jack (16) are connected in parallel. Proportional flow valve V (10-5) and one-way valve IV (13-4) are set. The proportional flow valve IV (10-4) and one-way valve III (13-3), the proportional flow valve V (10- 5) and the other end of the one-way valve IV (13-4) are connected to the electro-hydraulic reversing valve b through pipelines; Set a proportional flow valve I (10-1) on the outlet bypass of the emulsion pump I; The proportional flow valve I (10-1), proportional flow valve II (10-2), proportional flow valve III (10-3), proportional flow valve IV (10-4) and proportional flow valve V (10-5 ) are double liquid supply flow valves. The main valve controls the flow of the emulsion system, and the emulsified oil system supplies liquid to the pilot valve, which in turn controls the movement of the main valve. 2. The electro-hydraulic proportional control system of the hydraulic support based on the independent pilot liquid supply valve according to claim 1, characterized in that: proportional flow valve I (10-1), proportional flow valve II (10-2), proportional flow valve Valve III (10-3), proportional flow valve IV (10-4), and proportional flow valve V (10-5) have the same structure. They all include a symmetrical cylinder main valve and a three-position four-way servo slide valve as a pilot valve. (10-108). 3. The electro-hydraulic proportional control system of the hydraulic support based on the independent pilot liquid supply valve according to claim 2, characterized in that: the symmetrical cylinder main valve includes a flow valve main valve sleeve (10-103), and the flow valve main valve sleeve (10-103) has a pilot valve oil inlet (10-104) connected to the three-position four-way servo slide valve (10-108), and the flow valve main valve sleeve (10-103) is provided with upper and lower settings Through hole, there is a flow valve main valve core (10-105) in the through hole, a flow valve main valve sensor (10-106) is installed on the top of the flow valve main valve core (10-105), and a flow valve main valve sleeve (10-103) is provided with a flow valve main valve liquid inlet (10-101) and a flow valve main valve liquid outlet (10-102) at the bottom of the through hole. The flow valve main valve core (10-105) includes an upper and lower Sectional conduction piston structure, the upper conduction piston structure of the flow valve main valve core (10-105) divides the through hole from top to bottom into the flow valve main valve upper chamber (10-107), the flow valve main valve control upper chamber The chamber (10-109) and the flow valve main valve control the lower chamber (10-110), and the three-position four-way servo slide valve (10-108) controls the upper chamber (10-109) and flow valve main valve respectively through the flow channel and the flow valve main valve. The main valve of the flow valve controls the connection of the lower chamber (10-110), thereby controlling the movement of the main spool (10-105) of the flow valve. 4. The hydraulic support electro-hydraulic proportional control system based on an independent pilot liquid supply valve according to claim 3, characterized in that: low-pressure and small-flow emulsified oil enters through the pilot valve inlet (10-104) of the proportional flow valve. The three-position four-way servo slide valve (10-108), the emulsified oil then moves from the three-position four-way servo slide valve (10-108) through the drive flow valve main valve core (10-105), and the high-pressure and large-flow emulsion passes through The flow valve main valve liquid inlet (10-101) and the flow valve main valve liquid outlet (10-102) promote the movement of the hydraulic support cylinder or bypass control the output flow of the emulsion pump. The three-position four-way servo slide valve (10 The emulsified oil discharged from -108) flows back to the emulsified oil tank through the pilot oil outlet (10-111) of the flow valve. 5. The electro-hydraulic proportional control system of a hydraulic support based on an independent pilot liquid supply valve according to claim 4, characterized in that: the main valve sleeve (10-103) of the proportional flow valve is made of aluminum bronze, and the flow valve The main valve core (10-105) is made of 17-4Ph martensitic stainless steel. 6. The electro-hydraulic proportional control system of the hydraulic support based on the independent pilot liquid supply valve according to claim 4, characterized in that: the main valve inlet and outlet of the proportional flow valve II (10-2) are respectively equipped with pre-valve pressure sensors. I (12-1) and post-valve pressure sensor I (14-1); the main valve inlet and outlet of the proportional flow valve III (10-3) are respectively equipped with a pre-valve pressure sensor II (12-2) and a post-valve pressure sensor. Sensor II (14-2); the main valve inlet and outlet of the proportional flow valve III (10-4) are respectively equipped with a pre-valve pressure sensor III (12-3) and a post-valve pressure sensor III (14-3); proportional flow The main valve inlet and outlet of valve V (10-5) are respectively equipped with a pressure sensor IV (12-4) before the valve and a pressure sensor IV (14-4) after the valve. 7. A control method using the electro-hydraulic proportional control system of a hydraulic support based on an independent pilot liquid supply valve according to any one of claims 1 to 6, characterized in that the support movement proportional control method is as follows: First, according to the requirements of the coal mining process, the expected movement speed curve of the push jack or column jack is proposed, and the flow rate required for the movement is calculated based on the size of each cylinder; Use the pre-valve pressure sensor I (12-1), the pre-valve pressure sensor II (12-2), the pre-valve pressure sensor III (12-3), the pre-valve pressure sensor IV (12-4) and the post-valve pressure sensor respectively. I (14-1), post-valve pressure sensor II (14-2), post-valve pressure sensor III (14-3), post-valve pressure sensor IV (14-4) measure proportional flow valve II (10-2), Main valve inlet and outlet pressure of proportional flow valve III (10-3), proportional flow valve IV (10-4), proportional flow valve V (10-5); According to the main valve port opening, pressure difference and output flow formula, the proportional flow valve II (10-2), proportional flow valve III (10-3), proportional flow valve IV (10-4), proportional flow rate are calculated The opening of the main valve core (10-105) of the flow valve of valve V (10-5); According to the opening requirements of the main spool of the flow valve (10-105), the movement of the three-position four-way servo slide valve (10-108) is controlled, so that the emulsified oil flows from the pilot valve inlet (10-104) through the three-position four-way The servo slide valve (10-108) enters the main valve control lower chamber (10-110), and the emulsified oil in the main valve control upper chamber (10-109) flows back to the flow valve through the three-position four-way servo slide valve (10-108) The pilot outlet (10-111) flows back to the emulsified oil tank. The main valve core (10-105) of the proportional flow valve moves upward under the action of the pressure difference between the upper and lower chambers controlled by the main valve, and the lower part of the main valve core (10-105) detaches. The valve sleeve thus opens; According to the speed curve of the cylinder, when the opening of proportional flow valve II (10-2), proportional flow valve III (10-3), proportional flow valve IV (10-4), proportional flow valve V (10-5) When it needs to be reduced, the three-position four-way servo slide valve (10-108) moves, so that the emulsified oil enters the main valve control from the pilot valve inlet (10-104) through the three-position four-way servo slide valve (10-108) cavity (10-110), the main valve controls the emulsified oil in the lower cavity (10-109) to flow back to the flow valve pilot outlet (10-111) through the three-position four-way servo slide valve (10-108) and back to the emulsified oil tank , the main valve core (10-105) of the proportional flow valve moves downward under the action of the pressure difference between the upper and lower chambers controlled by the main valve, and the opening of the main valve core (10-105) decreases; The flow valve main valve sensor (10-106) measures the displacement of the main valve core (10-105) in real time, sends it to the controller, and compares it with the calculated expected main valve displacement to control the main valve core displacement in a closed loop. 8. The control method according to claim 7, characterized in that the flow control method of the emulsion pump station is as follows: The controller calculates the flow required by the oil cylinder in real time based on the current movement of the hydraulic support, determines the working quantity of the emulsion pump according to the flow demand, and uses the proportional flow valve I (10-1) to adjust the output flow of the emulsion pump I (4); Specifically: when the stent requires a small amount of liquid, only the emulsion pump I (4) is turned on, and the high-power variable frequency motor I (5) of the emulsion pump I (4) operates at maximum speed, using the proportional flow valve I (10-1 ) controls the actual output flow of emulsion pump I (4); when emulsion pump I (4) alone cannot meet the emulsion flow demand, start emulsion pump II (6) which is set up in parallel with emulsion pump I (4). ), at this time, the high-power variable frequency motor I (5) and high-power variable frequency motor II (7) of the emulsion pump I (4) and the emulsion pump II (6) are running at maximum speed, using the proportional flow valve I (10-1 ) controls the actual output flow of the emulsion pump I (4); when the flow is not enough, another set of emulsion pumps is turned on; when the liquid demand of the stent is reduced, the emulsion pumps are turned off one by one. 9. A proportional unloading valve used in the electro-hydraulic proportional control system of a hydraulic support based on an independent pilot liquid supply valve according to claim 1, characterized in that: the proportional unloading valve (9) is a double liquid supply valve, Used to replace the electromagnetic unloading valve used on high-pressure and large-flow emulsion pump stations; the main valve of the proportional unloading valve (9) proportionally controls the pressure of the emulsion system, and the emulsified oil system provides the pilot valve of the proportional unloading valve (9) Emulsifies oil to control the movement of the main valve core; Specifically, it includes interconnected unloading valve check valve (9-1), unloading valve main valve (9-3) and unloading valve pilot valve (9-5), among which the unloading valve check valve (9-1 ), the unloading valve main valve (9-3) is arranged in the unloading valve housing (9-4); The unloading valve housing (9-4) is provided with left and right through holes, and the unloading valve check valve (9-1) is arranged on the left side of the through hole of the unloading valve housing (9-4). The unloading valve main valve (9-3) is installed in the right side of the through hole of the unloading valve housing (9-4), the unloading valve check valve (9-1), the unloading valve main valve (9-3) The liquid inlets are arranged opposite to each other with a cavity between them. The cavity is provided with an unloading valve main valve liquid inlet (9-2) on the side of the unloading valve housing (9-4), and an unloading valve check valve. The liquid outlet of (9-1) is provided with an unloading valve check valve liquid outlet (9-10) on the unloading valve housing (9-4). The outlet of the unloading valve main valve (9-3) The liquid port is provided with an unloading valve main valve liquid return port (9-9) on the unloading valve housing (9-4), and the unloading valve main valve liquid return port (9-9) is connected to the unloading valve pilot valve Liquid return hole (9-8); The unloading valve pilot valve (9-5) includes an unloading valve pilot valve poppet valve assembly (9-51) and an unloading valve pilot valve single nozzle flapper valve assembly (9-52) that are connected to each other. The unloading valve pilot valve The single nozzle damper valve assembly (9-52) is provided with an unloading valve nozzle damper valve oil outlet (9-6) and an unloading valve nozzle damper valve oil inlet (9-7); The unloading valve check valve (9-1) includes an unloading valve check valve sleeve (9-11). The tail of the unloading valve check valve sleeve (9-11) is provided with an unloading valve check for blocking. The directional valve screw plug (9-14), the unloading valve check valve sleeve (9-11) is equipped with the unloading valve check valve spool (9-12), the unloading valve check valve spool (9 There is an unloading valve check valve spring (9-13) between -12) and the unloading valve check valve plug (9-14); the end and side wall of the unloading valve check valve (9-1) Opening, the unloading valve check valve spool (9-12) moves to control the connection and shutdown between the end and the side wall opening; The unloading valve main valve (9-3) includes an unloading valve main valve sleeve (9-31). The tail of the unloading valve main valve sleeve (9-31) is provided with an unloading valve main valve bonnet (9-34). ), the unloading valve main valve sleeve (9-31) is equipped with the unloading valve main spool (9-32), the unloading valve main spool (9-32) and the unloading valve main valve bonnet (9 There is an unloading valve main spring (9-33) between -34). The end and side wall opening of the unloading valve main valve sleeve (9-31) passes through the unloading valve main valve core (9-32). Move to control the conduction and shutoff between the end and the side wall opening; among them, the main valve core of the unloading valve (9-32) has a through hole at the end, and the main valve cover (9-34) of the unloading valve has a through hole. The unloading valve main valve bonnet through hole (9-35) communicates with the unloading valve main valve core (9-32) through hole; The unloading valve pilot valve poppet assembly (9-51) includes the unloading valve pilot valve housing (9-5109). The unloading valve pilot valve housing (9-5109) is a cylindrical structure with one end sealed and the other open. The open end of the unloading valve pilot valve housing (9-5109) is provided with a sealing unloading valve pilot valve plug (9-5108), and the unloading valve pilot valve housing (9-5109) is provided with a cavity space. , the cavity space is provided with an unloading valve pilot valve spool (9-5105) with a tapered end structure and a valve seat matching the unloading valve pilot valve spool (9-5105). The valve seat and the unloading valve The unloading valve pilot valve oil inlet chamber (9-5107) is formed between the pilot valve screw plugs (9-5108), and the unloading valve pilot valve oil inlet chamber (9-5107) is connected to the unloading valve pilot valve liquid inlet hole ( 9-5110), the tail of the unloading valve pilot valve spool (9-5105) is connected to the unloading valve pilot valve spring control piston (9-5103) through the unloading valve pilot valve spring (9-5104), and the unloading valve pilot valve spring control piston (9-5103) A spring chamber is formed between the valve spring control piston (9-5103) and the valve seat. There is an oil inlet chamber on the plug valve seat that can be controlled by the unloading valve pilot valve core (9-5105) to conduct the unloading valve pilot valve. (9-5107) and the unloading valve pilot valve damping hole (9-5106) in the spring chamber. The spring chamber is connected to the unloading valve pilot valve return hole (9-5111), and the unloading valve pilot valve spring controls the piston (9- 5103) and the sealing section of the unloading valve pilot valve housing (9-5109) form an unloading valve pilot valve control cavity (9-5102), and the unloading valve pilot valve control cavity (9-5102) is connected to the unloading valve The oil inlet of the pilot valve control chamber (9-5101), and the unloading valve pilot valve spring control piston (9-5103) are provided with a protrusion at the bottom to prevent the oil inlet of the unloading valve pilot valve control chamber from being blocked (9-5101 ); The unloading valve pilot valve single nozzle flapper valve assembly (9-52) includes an unloading valve nozzle valve housing (9-5207). The lower half of the unloading valve nozzle valve housing (9-5207) is equipped with a left and right direction through hole, the left side of the through hole is connected to the unloading valve nozzle baffle valve oil inlet (9-7) through the unloading valve nozzle valve oil inlet (9-5208), and the right side of the through hole is connected through the unloading valve nozzle valve The oil return port (9-5213) is connected to the oil outlet (9-6) of the unloading valve nozzle baffle valve. The through hole is equipped with a component that can control the movement of the baffle according to the control signal. The component includes a lower guide magnet (9 -5201) and the upper magnet (9-5203). There is an armature (9-5202) between the lower magnet (9-5201) and the upper magnet (9-5203). The armature (9-5202) is vertically located in the middle. There is a spring tube (9-5205). The spring tube (9-5205) is equipped with a baffle (9-5206) that blocks the through hole. The armature (9-5202) is wound with a coil (9-5204), which is located on the baffle. (9-5206) There is an unloading valve nozzle (9-5212) pointing to the right through the unloading valve nozzle valve spray group screw plug (9-5211) in the left through hole, and the unloading valve nozzle valve oil inlet hole ( 9-5208) is connected to the unloading valve nozzle (9-5212) through the unloading valve nozzle valve damping hole (9-5209), and the unloading valve nozzle valve damping hole (9-5209) is connected to the unloading valve nozzle (9-5212 ) is provided with a cavity, and the cavity is connected with an unloading valve, nozzle, baffle valve control connection hole (9-5210); The low-pressure and low-flow emulsified oil enters the unloading valve pilot valve single nozzle baffle valve assembly (9-52) through the unloading valve nozzle baffle valve oil inlet (9-7), and is sprayed by the unloading valve nozzle (9-5212). The discharged emulsified oil flows back to the emulsified oil tank through the return hole (9-8) of the unloading valve pilot valve. 10. The proportional unloading valve according to claim 9, characterized in that the working method of the proportional unloading valve (9) is as follows: When the pressure of the support hydraulic system is higher than the unloading pressure of the unloading valve, the unloading valve pilot valve (9-5) acts, causing the baffle (9-5206) to move away from the unloading valve nozzle (9-5212), causing the The emulsion is drained from the unloading valve nozzle valve return port (9-5213), causing the pressure in the unloading valve pilot valve control chamber (9-5102) to gradually decrease, and the unloading valve pilot valve spool (9-5105) gradually The valve seat is detached to open, the pressure in the upper chamber of the unloading valve main valve core (9-32) gradually decreases, the unloading valve main valve core (9-32) is slowly opened, and the unloading valve main valve sleeve (9-31 )'s end opening is connected to the openings on both sides to achieve gradual proportional unloading; When the actuator of the hydraulic support continues to operate or the system leaks and the system pressure is lower than the loading pressure, the baffle (9-5206) gradually moves toward the nozzle (9-5212), and the unloading valve pilot valve controls the cavity. (9-5102) gradually rises, the unloading valve pilot valve spool (9-5105) gradually closes, the pressure in the upper chamber of the unloading valve main spool (9-32) rises, and the unloading valve main valve (9-32) ) slowly closes, the unloading valve check valve (9-1) opens, and the system pressure gradually increases proportionally to the unloading pressure of the proportional unloading valve (9).