Water-based proportional valve

Abstract

The present application belongs to the technical field of electro-hydraulic valve, and specifically relates to a novel water-based proportional valve of hydraulic support. The novel water-based proportional valve comprises a No. 1 valve and a No. 2 valve with the same structure, wherein the No. 1 valve and the No. 2 valve respectively comprise a main circuit and a pilot hydraulic bridge circuit; the main circuit comprises a hydraulic control reversing valve; the pilot hydraulic bridge circuit comprises an electromagnetic switch valve and a high-speed switch valve connected in sequence, and a pilot hydraulic bridge circuit output end is arranged on a connection liquid path of the electromagnetic switch valve and the high-speed switch valve; the pilot hydraulic bridge circuit output end can output adjustable range hydraulic pressure to a hydraulic control port K of the hydraulic control reversing valve. The novel water-based proportional valve can be used as a proportional control mode for continuously automatically controlling flow, reducing flow pressure impact, and can also have a manual switch mode when a power failure or other fault occurs.

Description

Technical Field

[0001] This invention belongs to the field of electro-hydraulic valve technology, specifically a water-based proportional valve, which is often used in hydraulic supports in coal mines. Background Technology

[0002] Hydraulic supports in coal mines are essential support equipment for fully mechanized mining faces. They not only provide a safe space for underground personnel and equipment but also work in conjunction with the coal mining machine and scraper conveyor. Precise position control of each hydraulic cylinder is required when adjusting the posture of the hydraulic support or straightening the scraper conveyor. However, currently, each hydraulic cylinder is controlled by electro-hydraulic switching valves or manually operated valves, which cannot adjust the valve opening or precisely control the flow rate. This results in the hydraulic support's posture and the scraper conveyor's straightness control failing to meet the requirements of the coal mining process, impacting production efficiency. Furthermore, the current electro-hydraulic switching valves have large flow rates, and rapid opening and closing can easily cause hydraulic shocks, damaging components and pipelines in the hydraulic system, affecting the system's stability and reliability, and even causing cylinder explosions.

[0003] Therefore, to achieve safe, stable, and efficient support for hydraulic supports, a novel electro-hydraulic control element capable of precisely controlling flow rate is urgently needed to achieve precise control of the hydraulic support's posture. To this end, this invention proposes a water-based proportional valve that not only controls the reversal of the hydraulic cylinder but also adjusts the valve opening and continuously controls the flow rate, solving the problems of inaccurate hydraulic cylinder positioning and large pressure shocks caused by existing electro-hydraulic switching valves or manually operated valves. Summary of the Invention

[0004] To address the above problems, this invention provides a water-based proportional valve.

[0005] This invention adopts the following technical solution: a water-based proportional valve, comprising a first valve and a second valve with identical structures.

[0006] The No. 1 valve and the No. 2 valve each include: a main circuit and a pilot hydraulic bridge circuit;

[0007] The main circuit includes a hydraulically controlled directional valve;

[0008] The pilot hydraulic bridge circuit includes an electromagnetic switch valve and a high-speed switch valve connected in sequence. A pilot hydraulic bridge circuit output end is provided on the connecting hydraulic line between the electromagnetic switch valve and the high-speed switch valve. The pilot hydraulic bridge circuit output end can output an adjustable range of hydraulic pressure to the hydraulic control port K of the hydraulic control directional valve.

[0009] In some embodiments, the hydraulic control directional valve is a two-position two-way hydraulic control directional valve, and the main circuit further includes a hydraulic control check valve, which is bypassed and connected to the working port of the two-position two-way hydraulic control directional valve.

[0010] In some embodiments, the hydraulic control port K of the hydraulic directional valve is connected to the output end of the pilot hydraulic bridge circuit, the inlet of the hydraulic directional valve is connected to the hydraulic power source, the outlet A of the hydraulic directional valve is connected to the inlet of the hydraulic check valve, the outlet of the hydraulic check valve is connected to the return line or the hydraulic power source, the hydraulic control port of the hydraulic check valve in valve number one is connected to the outlet of the hydraulic directional valve in valve number two, and the hydraulic control port of the hydraulic check valve in valve number two is connected to the outlet A of the hydraulic directional valve in valve number one.

[0011] In some embodiments, the hydraulic control directional valve is a two-position three-way hydraulic control directional valve. The inlet of the two-position three-way hydraulic control directional valve is connected to the oil source, the return port is connected to the return oil pipeline or the oil tank, and the working port is directly connected to the hydraulic cylinder cavity.

[0012] In some embodiments, the working port G of the solenoid switching valve is connected to the inlet port D of the high-speed switching valve. Either point between the working port G and the inlet port D can serve as the output end of the pressure-controlled pilot hydraulic bridge and be connected to the hydraulic control port K of the hydraulic control directional valve in the main circuit.

[0013] In some embodiments, a fixed liquid resistance and / or pressure reducing valve is provided between the working port G and the liquid inlet D of the electromagnetic switching valve and the high-speed switching valve.

[0014] In some embodiments, a control device is further included, which includes a pressure sensor I, a pressure sensor II, a displacement sensor, a flow calculation unit, and a controller. The pressure sensor I is connected to the outlet A of the two-position two-way hydraulic directional valve, the displacement sensor is connected to the inlet of the two-position two-way hydraulic directional valve, and the displacement sensor is connected to the hydraulic control port K of the two-position two-way hydraulic directional valve. The pressure sensor I, the pressure sensor II, and the displacement sensor are all connected to the flow calculation unit, and the flow calculation unit is connected to the controller.

[0015] In some embodiments, the controller is connected to the control port of the high-speed switching valve in the pilot hydraulic bridge circuit.

[0016] A manual control method for a novel water-based proportional valve for hydraulic supports.

[0017] When the hydraulic cylinder needs to move in the forward direction, the following operation is performed on valve number one:

[0018] By manually operating the manual button on the two-position three-way solenoid valve, the solenoid valve is moved to the upper working position, and the high-pressure liquid enters the control port K, causing the hydraulic control directional valve to switch to the left working position. The inlet and outlet A of the hydraulic control directional valve are connected, and the high-pressure liquid directly enters the hydraulic cylinder to complete the liquid inlet. At the same time, the liquid in the other chamber of the hydraulic cylinder is returned through the hydraulic control check valve No. 2.

[0019] When the hydraulic cylinder needs to stop moving, release the manual button to return the two-position three-way solenoid valve to its original position, and the liquid in the control port will quickly flow back to the oil tank, disconnecting the inlet and outlet A of the hydraulic control directional valve.

[0020] When the hydraulic cylinder needs to move in the reverse direction, perform the same operation as above on valve number two.

[0021] An automatic control method for a novel water-based proportional valve for hydraulic supports.

[0022] The relationship between the duty cycle of the high-speed switching valve, the pressure at the control port K of the hydraulic directional valve, and the opening of the hydraulic directional valve is obtained through experimental or simulation techniques. That is, the relationship between the duty cycle, control pressure, and main valve opening, as well as the relationship between the flow rate, pressure, and main valve opening of the PA channel of the hydraulic directional valve, are obtained and put into the flow calculation unit.

[0023] The pressure P at the inlet of the hydraulic directional valve is measured by a pressure sensor. P The pressure P at the working port of the main valve is measured by a pressure sensor. A The displacement x of the valve core of the hydraulic directional valve is measured by a displacement sensor, which is the opening amount.

[0024] Based on the required flow rate Q and pressure P at port P of the hydraulic cylinder P With pressure P at port A A The flow calculation unit looks up the corresponding valve opening size and the corresponding main valve control port pressure in the table. The value is then sent to the controller. The controller finds the duty cycle of the high-speed switching valve at this time and sends the PWM wave signal of the corresponding duty cycle to the high-speed switching valve to adjust the control pressure of the hydraulic directional valve control port K, thereby controlling the main valve core opening size and the main valve port flow.

[0025] If the control device is in a power-off state due to a malfunction and the high-speed switching valve is in the normally closed position and cannot be operated, the manual control method shall be executed.

[0026] Compared with existing technologies, this invention is applicable to the control of hydraulic supports in underground coal mines. The combination of electromagnetic switching valves and high-speed switching valves in the pilot hydraulic bridge circuit, along with the use of fixed hydraulic resistance and pressure reducing valves, diversifies the structural types of pressure-controlled pilot hydraulic bridge circuits. This invention can be used in a proportional control mode for continuous automatic flow control, reducing flow pressure impact and improving the accuracy of hydraulic support cylinder position control. It also has a manual switching mode in case of power failures or other malfunctions, ensuring basic production in underground coal mines. This dual-insurance mode greatly improves the reliability of the new water-based proportional valve. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a water-based proportional valve, which is a two-position two-way hydraulically controlled directional valve.

[0028] Figure 2 This is a schematic diagram of the structure of a water-based proportional valve, which is a two-position three-way hydraulically controlled directional valve.

[0029] Figure 3 Example 1: Pilot hydraulic bridge circuit;

[0030] Figure 4 Example 2: Pilot hydraulic bridge circuit;

[0031] Figure 5 Example 3: Pilot hydraulic bridge circuit;

[0032] Figure 6 Example 4: Pilot hydraulic bridge circuit;

[0033] Figure 7 Example 5: Pilot hydraulic bridge circuit;

[0034] In the diagram, 1-Solenoid switch valve, 2-High-speed switch valve, 3-Two-position two-way hydraulic control directional valve, 4-Hydraulic control check valve, 5-Pressure sensor I, 6-Displacement sensor, 7-Pressure sensor II, 8-Flow calculation unit, 9-Controller, 10-Fixed hydraulic resistance, 11-Output terminal, 12-Pressure reducing valve, 14-Two-position three-way hydraulic control directional valve. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 1 As shown, a water-based proportional valve includes a main circuit, a pilot hydraulic bridge circuit, and a control device; the main valve working ports of valve No. 1 and valve No. 2 are respectively connected to the two cavities of a hydraulic cylinder, such as a hydraulic cylinder on a hydraulic support; the two sets of valves (valve No. 1 and valve No. 2) are used together to achieve bidirectional precise speed and position control of a hydraulic cylinder.

[0037] The main circuit consists of a two-position two-way hydraulic control directional valve 3 and a hydraulic control check valve 4. The two-position two-way hydraulic control directional valve 3 is normally closed, with its hydraulic control port K connected to the output end of the pilot hydraulic bridge circuit and its inlet connected to the oil source. The valve core opening of the two-position two-way hydraulic control directional valve 3 changes linearly with the hydraulic control port pressure. The inlet of the hydraulic control check valve 4 is also connected to the outlet A of the two-position two-way hydraulic control directional valve 3, the outlet of the hydraulic control check valve 4 is connected to the return pipeline or the oil tank, and the hydraulic control port of the hydraulic control check valve 4 is connected to the outlet of the two-position two-way hydraulic control directional valve in valve number two.

[0038] The hydraulic directional valve can also be a two-position three-way hydraulic directional valve. For a two-position three-way hydraulic directional valve, see... Figure 2 In the main circuit, there is no need for a bypass hydraulic control check valve 4. The inlet of the two-position three-way hydraulic control directional valve is connected to the oil source, the return port is connected to the return oil pipeline or oil tank, and the working port is directly connected to the hydraulic cylinder cavity.

[0039] The basic type of the pilot hydraulic bridge circuit consists of a solenoid valve 1 and a high-speed valve 2 connected in series, with the solenoid valve 1 preceding the high-speed valve 2. The solenoid valve 1 is a two-position, three-normally closed type, which also has a manual operation button. The high-speed valve 2 is a two-position, two-normally closed type. The working port G of the solenoid valve 1 is connected to the inlet port D of the high-speed valve 2. Either point between the working port G and the inlet port D can be used as the output end of the pressure-controlled pilot hydraulic bridge circuit, and is connected to the hydraulic control port K of the two-position, two-way hydraulic control directional valve 3 in the main circuit. The output pressure of the pressure-controlled pilot hydraulic bridge circuit can be controlled by pulse width modulation technology.

[0040] The pilot hydraulic bridge circuit can be connected in series with a fixed hydraulic resistance. The hydraulic resistance can be a single hydraulic resistance or the equivalent hydraulic resistance of multiple hydraulic resistances. The output terminal can be connected after the fixed hydraulic resistance ( Figure 2 ), or before fixing the liquid resistance ( Figure 3 The pilot hydraulic bridge circuit can simultaneously add a fixed hydraulic resistance valve and a pressure reducing valve. The high-speed switching valve 2 is located at the end of the series circuit. The series sequence of the solenoid switching valve 1, pressure reducing valve 12, and fixed hydraulic resistance 10 can be arbitrarily arranged and interchanged. The position of the output terminal 11 can also be arbitrarily changed at the outlets of these three components. Figure 4 , 5 Figure 6 shows three of the arrangement diagrams. Figure 4 The output end is positioned between the fixed liquid resistance and the high-speed switching valve 2; Figure 5 The output is positioned between the pressure reducing valve and the fixed liquid resistance; Figure 6 The output terminal is positioned between the fixed liquid resistance and the electromagnetic switch valve 1. Other arrangements and combinations are also possible and should be within the scope of protection of this invention.

[0041] The control device includes pressure sensor I5, pressure sensor II7, displacement sensor 6, flow calculation unit 8, and controller 9. Pressure sensor I5 is connected to outlet A of the two-position two-way hydraulic directional valve 3, displacement sensor 6 is connected to inlet of the two-position two-way hydraulic directional valve 3, and displacement sensor 6 is connected to hydraulic control port K of the two-position two-way hydraulic directional valve 3. Pressure sensor I5, pressure sensor II7, and displacement sensor 6 are all connected to flow calculation unit 8, and flow calculation unit 8 is connected to controller 9.

[0042] The control method is as follows:

[0043] 1) Switch control mode:

[0044] If the control system is in a power-off state due to a fault, the high-speed switching valve 2 will be in the normally closed position and cannot be operated. The entire water-based proportional valve must have a manual operation function to meet the most basic emergency switching requirements. By manually operating the manual button on the two-position three-way solenoid valve 1, the solenoid valve 1 is moved to the upper working position, and high-pressure fluid enters the control port K, causing the two-position two-way hydraulic control directional valve 3 to switch to the left working position. The P port of the two-position two-way hydraulic control directional valve 3 is connected to the A port, and the high-pressure fluid directly enters the hydraulic cylinder to complete the fluid inlet. At the same time, the fluid in the other chamber of the hydraulic cylinder is returned through the hydraulic control check valve No. 2. When the hydraulic cylinder needs to stop moving, the manual button is released, causing the two-position three-way solenoid valve 1 to return to its original position. The fluid in the control port quickly flows back to the oil tank, and the P port of the two-position two-way hydraulic control directional valve 3 is disconnected from the A port. When the hydraulic cylinder needs to move in the reverse direction, the same operation is performed on the valve No. 2.

[0045] 2) Proportional control mode:

[0046] The duty cycle of the high-speed switching valve 2, the pressure at the control port K of the two-position two-way hydraulic directional valve 3, and the opening amount of the two-position two-way hydraulic directional valve 3 are determined in advance through experiments or simulations. That is, the relationship between duty cycle, control pressure, and main valve opening amount, as well as the relationship between flow rate, pressure, and main valve opening amount at the PA channel of the two-position two-way hydraulic directional valve 3, are presented in a table and placed in the flow calculation unit 8. Then, the pressure sensor 7 measures the inlet pressure P of the two-position two-way hydraulic directional valve 3. P The pressure P at the main valve working port is measured by pressure sensor 5. A The displacement x (i.e., opening amount) of the main valve spool is measured by displacement sensor 6. Based on the required flow rate Q and port pressure P of the hydraulic cylinder... P With pressure P at port A A The corresponding valve opening size and the corresponding main valve control port pressure are obtained by looking up the table in the flow calculation unit 8. This value is then sent to the controller 9. The controller automatically finds the duty cycle corresponding to the high-speed switching valve 2 at this time and sends a PWM wave signal with the corresponding duty cycle to the high-speed switching valve 2. This adjusts the control pressure of the main valve control port K, thereby controlling the opening size of the main valve core and the flow rate of the main valve, thus achieving precise control of the speed and position of the hydraulic cylinder.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water-based proportional valve, characterized in that, Including valves No. 1 and No. 2, which have the same structure. The No. 1 valve and the No. 2 valve each include: a main circuit and a pilot hydraulic bridge circuit; The main circuit includes a hydraulically controlled directional valve; The pilot hydraulic bridge circuit includes an electromagnetic switch valve (1) and a high-speed switch valve (2) connected in sequence. The pilot hydraulic bridge circuit output end is provided on the connecting hydraulic line of the electromagnetic switch valve (1) and the high-speed switch valve (2). The pilot hydraulic bridge circuit output end can output an adjustable range of hydraulic pressure to the hydraulic control port K of the hydraulic control directional valve. The hydraulic control port K of the hydraulic control directional valve (3) is connected to the output end of the pilot hydraulic bridge circuit. The inlet of the hydraulic control directional valve (3) is connected to the hydraulic power source. The outlet A of the hydraulic control directional valve (3) is connected to the inlet of the hydraulic control check valve (4). The outlet of the hydraulic control check valve (4) is connected to the return pipeline or the hydraulic power source. The hydraulic control port of the hydraulic control check valve (4) in valve No. 1 is connected to the outlet of the hydraulic control directional valve in valve No.

2. The hydraulic control port of the hydraulic control check valve (4) in valve No. 2 is connected to the outlet A of the hydraulic control directional valve (3) in valve No.

1.

2. The water-based proportional valve according to claim 1, characterized in that, The hydraulic control directional valve is a two-position two-way hydraulic control directional valve (3). The main circuit also includes a hydraulic control check valve (4), which is bypassed to the working port of the two-position two-way hydraulic control directional valve (3).

3. The water-based proportional valve according to claim 1, characterized in that, The hydraulic control directional valve is a two-position three-way hydraulic control directional valve (14). The inlet of the two-position three-way hydraulic control directional valve (14) is connected to the oil source, the return port is connected to the return oil pipeline or oil tank, and the working port is directly connected to the hydraulic cylinder cavity.

4. The water-based proportional valve according to claim 1 or 3, characterized in that, The working port G of the electromagnetic switch valve (1) is connected to the inlet port D of the high-speed switch valve (2). Any point between the working port G and the inlet port D can be used as the output end of the pressure-controlled pilot hydraulic bridge circuit and connected to the hydraulic control port K of the hydraulic control directional valve in the main circuit.

5. The water-based proportional valve according to claim 4, characterized in that, A fixed liquid resistance and / or pressure reducing valve is provided between the working port G and the liquid inlet D of the electromagnetic switch valve (1) and the high-speed switch valve (2).

6. The water-based proportional valve according to claim 5, characterized in that, It also includes a control device, which includes a pressure sensor I (5), a pressure sensor II (7), a displacement sensor (6), a flow calculation unit (8), and a controller (9). The pressure sensor I (5) is connected to the outlet A of the two-position two-way hydraulic control valve (3), the displacement sensor (6) is connected to the inlet of the two-position two-way hydraulic control valve (3), and the displacement sensor (6) is connected to the hydraulic control port K of the two-position two-way hydraulic control valve (3). The pressure sensor I (5), the pressure sensor II (7), and the displacement sensor (6) are all connected to the flow calculation unit (8), and the flow calculation unit (8) is connected to the controller (9).

7. The water-based proportional valve according to claim 6, characterized in that, The controller (9) is connected to the control port of the high-speed switching valve (2) in the pilot hydraulic bridge circuit.

8. A manual control method for a water-based proportional valve as described in claim 4, characterized in that, When the hydraulic cylinder needs to move in the forward direction, the following operation is performed on valve number one: By manually operating the manual button on the two-position three-way solenoid switch valve (1), the solenoid switch valve (1) is moved to the upper working position, and the high pressure liquid enters the control port K, causing the hydraulic control directional valve to switch to the left working position. The inlet of the hydraulic control directional valve is connected to the outlet A, and the high pressure liquid directly enters the hydraulic cylinder to complete the liquid inlet. At the same time, the liquid in the other chamber of the hydraulic cylinder is returned through the hydraulic control check valve No.

2. When the hydraulic cylinder needs to stop moving, release the manual button so that the two-position three-way solenoid valve (1) returns to its original position, the liquid in the control port flows back to the oil tank quickly, and the inlet and outlet A of the hydraulic control directional valve are disconnected. When the hydraulic cylinder needs to move in the reverse direction, perform the same operation as above on valve number two.

9. An automatic control method for a water-based proportional valve as described in claim 6, characterized in that, The relationship between the duty cycle of the high-speed switching valve (2), the pressure of the control port K of the hydraulic directional valve and the opening amount of the hydraulic directional valve is obtained by means of experiment or simulation technology. That is, the relationship between the duty cycle, control pressure and main valve opening amount, as well as the relationship between the flow rate, pressure and main valve opening amount of the PA channel of the hydraulic directional valve, are made into a table and put into the flow calculation unit (8). The pressure P at the inlet of the hydraulic control directional valve is measured by the pressure sensor (7). P The pressure P at the working port of the main valve is measured by the pressure sensor (5). A The displacement x of the hydraulic directional valve core is measured by the displacement sensor (6), which is the opening amount. Based on the required flow rate Q and pressure P at port P of the hydraulic cylinder P With pressure P at port A A In the flow calculation unit (8), the corresponding valve opening size and the corresponding main valve control port pressure are obtained by looking up the table. The value is sent to the controller (9). The controller (9) finds the duty cycle of the high-speed switching valve (2) at this time, and sends the PWM wave signal of the corresponding duty cycle to the high-speed switching valve (2) to adjust the control pressure of the hydraulic control directional valve control port K, thereby controlling the opening size of the main valve core and the flow rate of the main valve. If the control device is in a power-off state due to a fault, and the high-speed switching valve (2) is in the normally closed position and cannot be operated, the manual control method as described in claim 8 shall be executed.

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