Composite pilot device, system and unloading valve for coal mine emulsification pump station

Abstract

The present invention discloses a composite pilot device, system and unloading valve for a coal mine emulsification pump station, and mainly relates to the field of unloading valves for emulsion pump stations. The device includes an electromagnetic proportional valve and a three-channel pilot valve; a proportional push rod is mounted on the electromagnetic proportional valve, and the proportional push rod realizes telescopic movement in at least three gears on a linear stroke through electromagnetic control of the electromagnetic proportional valve; a pilot valve core with a linear reciprocating stroke is installed in the three-channel pilot valve, and one end of the pilot valve core is connected to the outer end of the proportional push rod to synchronize the strokes of the two. Three liquid channels are arranged in parallel on the valve body of the three-channel pilot valve, and an external medium interface is arranged at the outer end of the pilot valve core. A connecting channel that penetrates the medium channel is arranged on the side wall of the pilot valve core, and the three-gear stroke of the proportional push rod can make the connecting channel connected with the three flow channels respectively. The beneficial effect of the present invention is that once the liquid path in the unloading valve is blocked, it can automatically switch to a smooth channel to continue normal operation.

Description

Technical Field

[0001] The invention relates to the field of unloading valves for emulsion pumping stations, in particular to a composite pilot device, a system and an unloading valve for coal mine emulsification pumping stations. Background Art

[0002] The traditional electromagnetic / mechanical unloading valve (hereinafter referred to as the main valve) for coal mine emulsion pump station is equipped with a single liquid flow channel electromagnetic pilot valve or mechanical pilot valve. The defect of the existing unloading valve products is that the oil passage used for control is easily blocked. Once the liquid flow channel is blocked, the entire unloading valve will fail.

[0003] At the same time, the electromagnetic pilot valve (mechanical pilot valve) that is matched with the traditional electromagnetic / mechanical unloading valve is matched with an ordinary electromagnet, that is, the core ejection length after the coil is energized is consistent with the retraction length after the coil is de-energized, and the current input is constant, so only opening and closing control can be achieved. There is a lack of adaptive relief measures for the blockage of the oil passage, making the blockage of the liquid flow channel the main problem affecting the operation of the unloading valve, and also the core bottleneck that leads to the service life of the unloading valve. Summary of the invention

[0004] The purpose of the present invention is to provide a composite pilot device, system and unloading valve for a coal mine emulsification pump station, which provides multiple switchable liquid channels so that once the liquid channel in the unloading valve is blocked, it can automatically switch to a smooth channel to continue normal operation.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] Composite pilot device for coal mine emulsification pump station, including electromagnetic proportional valve and three-channel pilot valve;

[0007] The electromagnetic proportional valve is equipped with a proportional push rod for output, and the proportional push rod is controlled by the electromagnetic proportional valve to achieve extension and retraction of at least three gears in a linear stroke;

[0008] A pilot valve core with a linear reciprocating stroke is installed in the three-channel pilot valve, one end of the pilot valve core is connected to the outer end of the proportional push rod so that the strokes of the two are synchronized, a first liquid flow channel, a second liquid flow channel, and a third liquid flow channel are arranged in parallel on the valve body of the three-channel pilot valve, an external medium interface is provided at the outer end of the pilot valve core, a medium channel connected to the external medium interface is provided in the pilot valve core, a connecting channel that penetrates the medium channel is provided on the side wall of the pilot valve core, and the three-speed stroke of the proportional push rod can make the connecting channel connected to the first liquid flow channel, the second liquid flow channel, and the third liquid flow channel respectively.

[0009] The external medium interface is connected with a pressure medium pipe, and the pressure medium pipe is used to communicate with the liquid path of the unloading valve.

[0010] The input voltage of the electromagnetic proportional valve is DC24V, and the power is not more than 3W. The maximum surface temperature of the proportional electromagnet of the electromagnetic proportional valve does not exceed 150 degrees Celsius when coal dust accumulates on its surface.

[0011] A composite pilot system for a coal mine emulsification pump station, comprising the composite pilot device described above, and a pressure acquisition module, including a PLC control module;

[0012] The pressure collection module is arranged on the pressure medium channel of the unloading valve, and is used to collect the pressure in the channel and the valve cavity, and the PLC control module feeds back the pressure signal;

[0013] The PLC control module is used to obtain the pressure data of the pressure acquisition module, and convert the pressure data into an electrical signal in direct proportion, and control the gear position of the electromagnetic proportional valve according to the electrical signal.

[0014] The pressure acquisition module includes an explosion-proof intrinsically safe pressure sensor.

[0015] An unloading valve for a coal mine emulsification pump station, comprising a main valve and a mechanical pilot valve used in conjunction with each other, and also comprising the above-mentioned composite pilot device, a pressure sensor, and a PLC control module;

[0016] The pressure sensor is installed on the pressure medium pipe channel of the main valve and is used to obtain pressure data in the main valve;

[0017] The PLC control module is used to receive pressure data, convert the pressure data into an electrical signal in direct proportion, and control the gear position of the electromagnetic proportional valve according to the electrical signal;

[0018] The fluid path of the main valve and the mechanical pilot valve is communicated through the pilot valve core of the three-channel pilot valve, and is selectively communicated through the first fluid flow channel, the second fluid flow channel, and the third fluid flow channel.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] This technology can realize automatic conversion of liquid flow channels through a composite pilot device, and can realize response to voltage changes in the liquid path in the unloading valve body through an electromagnetic proportional valve, that is, the mutual cooperation between the main valve, the electromagnetic proportional valve and the three-channel pilot valve. Once a channel is blocked, another channel can be automatically switched to work normally. Its operating principle is: the pressure is collected by an explosion-proof intrinsically safe pressure sensor and transmitted to the PLC system through an intrinsically safe explosion-proof circuit chip. The PLC sends different current instructions to the electromagnetic proportional valve according to the pressure. The proportional solenoid realizes the proportional movement of its valve core according to the received current. The valve core of the electromagnetic proportional valve pushes the pilot valve push rod to realize the linear stroke position switching of three gears. Once the pressure increases, the moving distance moves in direct proportion to the ratio of current to pressure according to the current size, switching the first liquid flow channel, the second liquid flow channel, the third liquid flow channel and the connecting channel, so that the valve core is displaced to realize the long-term unobstructed opening, so as to maintain the loading or unloading function of the main valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the installation position and application status of the composite pilot device on the main valve;

[0022] Figure 2 It is the initial state of the composite pilot device after the main valve is installed;

[0023] Figure 3 The composite pilot device is a working state in which the first liquid flow channel is automatically switched to the second liquid flow channel after the main valve is installed and the first liquid flow channel is blocked.

[0024] Figure 4 It is the working state of the composite pilot device when the second liquid flow channel is automatically switched to the third liquid flow channel after the main valve is installed and the second liquid flow channel is blocked.

[0025] Attached Figure 5 Flow chart of converting voltage data into electrical signals and amplifying the output.

[0026] Numbers shown in the accompanying drawings:

[0027] 1. Main valve; 2. Mechanical pilot valve; 3. Solenoid proportional valve; 4. Three-channel pilot valve; 5. Proportional valve core; 6. Proportional push rod; 7. Pilot valve core; 8. First liquid flow channel; 9. Second liquid flow channel; 10. Third liquid flow channel; 11. Medium channel; 12. External medium interface; 13. Pressure medium pipe. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the application equally.

[0029] The instruments, reagents, materials, etc. involved in the following embodiments, unless otherwise specified, are all conventional instruments, reagents, materials, etc. in the prior art and can be obtained through regular commercial channels. The experimental methods, detection methods, etc. involved in the following embodiments, unless otherwise specified, are all conventional experimental methods, detection methods, etc. in the prior art.

[0030] Example 1: Unloading valve with composite pilot device for coal mine emulsification pump station

[0031] Traditional mining electromagnetic / mechanical unloading valves (hereinafter referred to as main valve 1) are equipped with single-flow channel electromagnetic pilot valves, or mechanical pilot valves are used instead of electromagnetic pilot valves. The biggest drawback of these two traditional forms is that once the pilot valve flow channel is blocked, the entire main valve 1 will fail and cannot work. In order to overcome the blocking problem, the design scheme of this example is as follows:

[0032] The main structure includes a main valve 1 and a mechanical pilot valve 2 used in conjunction with each other. The structure of the main valve 1 is consistent with the unloading valve of the traditional coal mine emulsion pump station. As an innovative point of this solution, it also includes a composite pilot system for ensuring smooth passage of the main valve 1 and the mechanical pilot valve 2, namely, it includes: an electromagnetic proportional valve 3, a three-channel pilot valve 4, a pressure sensor, and a PLC control module.

[0033] The electromagnetic proportional valve 3 is connected to a power line, a proportional solenoid and a proportional valve core 5 are installed in the electromagnetic proportional valve 3, a proportional push rod 6 is connected to the proportional valve core 5 and is synchronized with the proportional push rod 6, one end of the proportional push rod 6 extends out of the electromagnetic proportional valve 3 and serves as an output component of the valve, and the proportional push rod 6 can be extended and retracted in at least three gears in a linear stroke through the electromagnetic control of the electromagnetic proportional valve 3;

[0034] The design high pressure ratio of the electromagnetic proportional valve 3 meets the requirements of GB3836.4 standard. The key points and difficulties of its design are:

[0035] a. It can be used in high pressure situations (pressure between 32-40Mpa) and can convert pressure signals into current signals proportionally;

[0036] b. This valve is different from the common pressure pilot valve. The hydraulic pressure on the valve core is compared with the electromagnetic suction of the proportional solenoid. By changing the current input to the proportional solenoid, the electromagnetic force can be changed, thereby changing the moving distance of the proportional push rod 6. Figure 2, Figure 3 , Figure 4 As shown;

[0037] c. The valve is used in underground coal mines, which are flammable and explosive places, so it must meet the requirements of GB3836.4 standard. The input voltage is DC24V, the power is not more than 3W, and the maximum surface temperature of the proportional solenoid when coal dust may accumulate on its surface does not exceed 150 degrees Celsius.

[0038] The fluid path of the main valve 1 and the mechanical pilot valve 2 is connected through the pilot valve core 7 of the three-channel pilot valve 4, and is connected through one of the first liquid flow channel 8, the second liquid flow channel 9, and the third liquid flow channel 10. The specific structure is as follows:

[0039] The three-channel pilot valve 4 is provided with a pilot valve core 7 with a linear reciprocating stroke. One end of the pilot valve core 7 is connected to the outer end of the proportional push rod 6 so that the strokes of the two are synchronized. It also has a linear stroke output of three gears. The valve body of the three-channel pilot valve 4 is provided with a first liquid flow channel 8, a second liquid flow channel 9, and a third liquid flow channel 10 in parallel. The outer end of the pilot valve core 7 is provided with an external medium interface 12. The external medium interface is connected with a pressure medium pipe 13, and the pressure medium pipe 13 is used to communicate with the liquid path of the unloading valve. The pilot valve core 7 is provided with a medium channel 11 connected with the external medium interface. The side wall of the pilot valve core 7 is provided with a connecting channel that penetrates the medium channel 11. The three-gear stroke of the proportional push rod 6 can make the connecting channel communicate with the first liquid flow channel 8, the second liquid flow channel 9, and the third liquid flow channel 10 respectively. Through the follow-up of the pilot valve core 7 to the proportional push rod 6, the first liquid flow channel 8, the second liquid flow channel 9, the third liquid flow channel 10 and the connecting channel are switched and connected to one of them at three travel gears. The connecting channel and the external medium interface are respectively used as two inlet and outlet ports of the medium channel 11, which are used to connect to the liquid path of the main valve 1 and the mechanical pilot valve 2, so that the liquid path of the main valve 1 and the mechanical pilot valve 2 are connected in series through the medium path, and the switching of the first liquid flow channel 8, the second liquid flow channel 9, and the third liquid flow channel 10 can ensure the connection of the three parallel channels between the liquid path of the main valve 1 and the mechanical pilot valve 2.

[0040] The pressure sensor is installed on the pressure medium channel of the main valve 1 (unloading valve) and is used to obtain the pressure data in the main valve 1; the pressure sensor is used to obtain the pressure data in the pressure medium channel of the main valve 1, and can intuitively reflect whether there is a liquid circuit blockage problem based on the pressure data.

[0041] The PLC control module is used to obtain the pressure data of the pressure acquisition module, and convert the pressure data into an electrical signal in direct proportion, and control the gear position of the electromagnetic proportional valve 3 according to the electrical signal. The main valve 1 and the pilot valve are changed by the electromagnetic proportional valve 3 according to the current signal size converted by the pressure ratio, and the stroke of the proportional valve core 5 and the proportional push rod 6 is changed to realize the displacement of the pilot valve core 7 and the push rod. Once a liquid flow channel is blocked, another channel can be automatically switched to work normally.

[0042] The working principle of this unloading valve is:

[0043] a. Proportional control is adopted. Proportional control is a control method that continuously controls the hydraulic pressure and the displacement of the actuator in proportion to the current signal converted from the hydraulic pressure.

[0044] b. The composite pilot mechanism is both an electro-hydraulic conversion element and a power amplifier element. The electronic proportional amplifier therein converts an input electrical signal voltage value into a corresponding current signal. This current signal is sent to the proportional electromagnet as the input of the electromagnetic proportional valve 3. The electromagnet converts this current into a force acting on the proportional valve core 5. As the current increases, the output force increases accordingly. This force pushes the valve core and acts on the proportional push rod 6 to achieve channel conversion. Through such a conversion process, a change in an input electrical signal can control the displacement of the actuator (push rod).

[0045] Example 2: Performance test of the unloading valve described in Example 1

[0046] 1. Testing basis

[0047] MT / T 188.3 Test methods specified in the technical requirements for unloading valves of emulsion pump stations for coal mines.

[0048] 2. Detection Method

[0049] 2.1 Attachment Figure 1 It is required to assemble the pilot system with the main valve 1 and open the first liquid flow channel 8 (see attached Figure 2 (At this time, the three liquid flow channels are not blocked) and the performance test is carried out. The test results are shown in Table 1

[0050] Table 1 Performance test results

[0051] Project Name Technical requirements chapter number Test method chapter number Test Results External leakage test 4.5.2 5.2.1 Meet the requirements Internal leakage test 4.5.3 5.2.2 Meet the requirements Nominal pressure unloading test 4.5.4 5.2.3 Meet the requirements Nominal pressure recovery test 4.5.4 5.2.4 Meet the requirements Pressure adjustment range test 4.5.4 5.2.5 Meet the requirements Pressure loss test 4.5.4 5.2.6 Meet the requirements Overpressure unloading test 4.5.6 5.2.7 Meet the requirements Dynamic characteristics test 4.5.4 4.2.9 Meet the requirements

[0052] 2.2 Attachment Figure 1 It is required to assemble the pilot system with the main valve 1, and move the valve core forward to open the second liquid flow channel 9 (the first liquid flow channel 8 is in a blocked state at this time), see the attached Figure 3 The performance test was carried out and the test results are shown in Table 2.

[0053] Table 2 Performance test results

[0054] Project Name Technical requirements chapter number Test method chapter number Test Results External leakage test 4.5.2 5.2.1 Meet the requirements Internal leakage test 4.5.3 5.2.2 Meet the requirements Nominal pressure unloading test 4.5.4 5.2.3 Meet the requirements Nominal pressure recovery test 4.5.4 5.2.4 Meet the requirements Pressure adjustment range test 4.5.4 5.2.5 Meet the requirements Pressure loss test 4.5.4 5.2.6 Meet the requirements Overpressure unloading test 4.5.6 5.2.7 Meet the requirements Dynamic characteristics test 4.5.4 4.2.9 Meet the requirements

[0055] 2.3 Attachment Figure 1 It is required to assemble the pilot system with the main valve 1, and move the valve core forward to open the third liquid flow channel 10 (at this time, the first liquid flow channel 8 and the second liquid flow channel 9 are in a blocked state), see the attached Figure 4 The performance test was carried out and the test results are shown in Table 3.

[0056] Table 3 Performance test results

[0057] Project Name Technical requirements chapter number Test method chapter number Test Results External leakage test 4.5.2 5.2.1 Meet the requirements Internal leakage test 4.5.3 5.2.2 Meet the requirements Nominal pressure unloading test 4.5.4 5.2.3 Meet the requirements Nominal pressure recovery test 4.5.4 5.2.4 Meet the requirements Pressure adjustment range test 4.5.4 5.2.5 Meet the requirements Pressure loss test 4.5.4 5.2.6 Meet the requirements Overpressure unloading test 4.5.6 5.2.7 Meet the requirements Dynamic characteristics test 4.5.4 4.2.9 Meet the requirements

[0058] 3. Technical effect evaluation

[0059] According to MT / T 188.3 coal mine emulsion pump station unloading valve technical conditions test requirements, respectively according to Figure 2 , Figure 3 , Figure 4 The specified liquid flow channel positions were tested as specified in Tables 1, 2 and 3, and the test results all met the requirements of the standards.

Claims

1. A composite pilot device for a coal mine emulsification pump station, characterized in that: Including solenoid proportional valve and three-channel pilot valve; The electromagnetic proportional valve is connected to a power line, a proportional solenoid and a proportional valve core are installed in the electromagnetic proportional valve, a proportional push rod is connected to the proportional valve core and is synchronized with the proportional push rod, and a proportional push rod for output is installed on the electromagnetic proportional valve, and the proportional push rod can be extended and retracted in at least three gears in a linear stroke through the electromagnetic control of the electromagnetic proportional valve; A pilot valve core with a linear reciprocating stroke is installed in the three-channel pilot valve, one end of the pilot valve core is connected to the outer end of the proportional push rod so that the strokes of the two are synchronized, a first liquid flow channel, a second liquid flow channel, and a third liquid flow channel are arranged in parallel on the valve body of the three-channel pilot valve, an external medium interface is arranged at the outer end of the pilot valve core, a medium channel connected to the external medium interface is arranged in the pilot valve core, a connecting channel that penetrates the medium channel is arranged on the side wall of the pilot valve core, and the three-speed stroke of the proportional push rod can make the connecting channel connected to the first liquid flow channel, the second liquid flow channel, and the third liquid flow channel respectively; The external medium interface is connected with a pressure medium pipe, and the pressure medium pipe is used to communicate with the liquid path of the unloading valve.

2. The composite pilot device for coal mine emulsification pump station according to claim 1 is characterized in that: The input voltage of the electromagnetic proportional valve is DC24V, and the power is not more than 3W. The maximum surface temperature of the proportional electromagnet of the electromagnetic proportional valve does not exceed 150 degrees Celsius when coal dust accumulates on its surface.

3. A composite pilot system for a coal mine emulsification pump station, characterized in that: It comprises a composite pilot device as claimed in any one of claims 1 to 2, and a pressure acquisition module, including a PLC control module; The pressure collection module is arranged on the pressure medium channel of the unloading valve, and is used to collect the pressure in the channel and the valve cavity, and the PLC control module feeds back the pressure signal; The PLC control module is used to obtain the pressure data of the pressure acquisition module, and convert the pressure data into an electrical signal in direct proportion, and control the gear position of the electromagnetic proportional valve according to the electrical signal.

4. A composite pilot system for a coal mine emulsification pump station according to claim 3, characterized in that: The pressure acquisition module includes an explosion-proof intrinsically safe pressure sensor.

5. An unloading valve for a coal mine emulsification pump station, comprising a main valve and a mechanical pilot valve used in conjunction with each other, characterized in that: It also includes a composite pilot device, a pressure sensor, and a PLC control module as described in any one of claims 1 to 2; The pressure sensor is installed on the pressure medium pipe channel of the main valve and is used to obtain pressure data in the main valve; The PLC control module is used to receive pressure data, convert the pressure data into an electrical signal in direct proportion, and control the gear position of the electromagnetic proportional valve according to the electrical signal; The fluid path of the main valve and the mechanical pilot valve is communicated through the pilot valve core of the three-channel pilot valve, and is selectively communicated through the first fluid flow channel, the second fluid flow channel, and the third fluid flow channel.

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