A high-speed electromagnetic pulse gas valve device

Abstract

The invention discloses a high-speed electromagnetic pulse gas valve device, wherein a cavity is provided between a valve body (18) and a gas chamber housing (6) as a gas chamber, an air inlet (7) is used to introduce working gas into the cavity, and the diffusion time of the magnetic field generated by the disc-shaped coil (16) through the stainless steel sheet (13) is less than 1 microsecond. The air inlet (7) is designed above the back of the piston (12), and the gas flows through the piston hole (11) on the piston (12), so that the air pressure difference on both sides of the piston (12) and the elastic force of the spring (9) are used as the restoring force for the piston (12) to close downward, thereby reducing the movement time of the closing process. By adjusting the size of the pulse current of the disc-shaped coil (16), the height of the piston (12) can be adjusted, thereby changing the movement time of the piston (12) switch and the size of the air intake. The disc-shaped coil (16) is isolated outside the gas chamber by the stainless steel sheet (13). According to tests, the gas valve can be used for pulse air intake of inflammable and explosive gases such as hydrogen, and can withstand a gas working pressure of more than 0.3Mpa.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic gas valves, and in particular to a high-speed electromagnetic pulse gas valve device. Background Art

[0002] The pulse width of traditional electromagnetic gas valves is usually more than tens of milliseconds. When the valve is closed, the injected gas has already diffused evenly in the vacuum chamber. If a certain amount of gas needs to be injected in a shorter time (such as milliseconds), or if the gas needs to be distributed in a local area of ​​the vacuum chamber before the experimental operation, these traditional electromagnetic valves can no longer meet the needs.

[0003] The reasons why traditional solenoid valves move slowly can be summarized as follows: 1) The moving iron core of traditional direct-acting solenoid valves has a large mass, resulting in a slow response time for the moving iron core; 2) Since the wire diameters of the stationary iron core wrapped with the external coil and the moving iron core serving as the piston along the direction of magnetic field diffusion are usually several centimeters, the time required for the magnetic field generated by the external coil to completely diffuse from the stationary iron core to the moving iron core is as high as several hundred microseconds. When the power supply is stopped, the response of the moving iron core will also be delayed by several hundred microseconds.

[0004] The present invention is a pulsed electromagnetic gas valve, the purpose of which is to be able to spray gas into a vacuum cavity (or a cavity with an internal and external pressure difference) in a short period of time, the time reaching the order of hundreds of microseconds, so that when the valve is closed, the gas in the vacuum cavity has not diffused to other areas, and only exists locally at a specific position. Summary of the invention

[0005] The technical problem to be solved by the present invention is: to provide a high-speed electromagnetic pulse gas valve device, which mainly solves the problem of realizing short pulse air intake during the gas valve switching process.

[0006] The technical solution adopted by the present invention is: a high-speed electromagnetic pulse gas valve device, a cavity as an air chamber is provided between the valve body 18 and the air chamber housing 6, the air inlet 7 is used to introduce working gas into the cavity, a disc-shaped piston 12 is provided in the cavity which can move up and down, and the material of the piston 12 is aluminum to reduce its weight; under the action of the spring 9, the piston 12 presses on the second O-ring 10 at the top of the lower valve stem 21, thereby disconnecting the air path between the air chamber and the lower valve stem 21. The tightness of the spring 9 is determined by the up and down position of the spring fixing seat 8. By rotating the handle 1, the upper valve stem 2 is driven to rotate in and out along the threaded channel of the upper housing 3, so as to adjust the up and down position of the spring fixing seat 8, the ball 5 is used to reduce the friction between the upper valve stem 2 and the spring fixing seat 8 during rotation, and the first O-ring 4 is used to seal the gap between the upper valve stem 2 and the air chamber housing 6. The disc-shaped coil 16 is installed in the groove of the valve body 18, and the groove and the external hole groove can be connected to the external terminal 22 through the lead 17. The disc-shaped stainless steel sheet 13 covers the disc-shaped coil 16, and the inner and outer sides of the stainless steel sheet 13 are compressed and sealed by the fourth O-ring 15 and the third O-ring 14 to prevent the outside air from entering the air chamber along the gap between the valve body 18 and the air chamber shell 6. The docking flange 20 is used to dock with the window of the vacuum chamber. The gas valve as a whole is screwed in along the central thread groove of the docking flange 20 with the lower valve stem 21, and the fifth O-ring 19 is compressed to achieve sealing, so as to prevent the gas from entering the vacuum chamber along the gap between the lower valve stem 21 and the docking flange 20.

[0007] The working mode of the quick air valve is as follows: the external capacitor circuit provides a single pulse current to the disc coil 16 through the terminal 22. Since the thickness of the stainless steel sheet 13 is only 0.03mm, the magnetic field generated by the energized disc coil 16 can quickly pass through the stainless steel sheet 13, induce current on the piston 12, and bounce the very light aluminum piston 12. At this time, there is a gap between the piston 12 and the second O-ring 10, so that the gas in the air chamber flows into the channel of the lower valve stem 21 through the piston hole 11 and sprays into the vacuum chamber.

[0008] The disc coil 16 is a single-layer disc coil made of copper enameled wire, with inner and outer diameters of 20 mm and 42 mm respectively. The diameter of the copper enameled wire is 1 mm, and it is wound 22 times. The inductance measured when it is installed in the air valve is 5 μH, and the capacitance of the external circuit connected is 200 μF. By selecting a suitable external resistor, the discharge is an over-damped discharge, and a single pulse current with a half-width of about 100 μs is obtained. Therefore, the time for the piston 12 to be accelerated upward by the electromagnetic force is about 200 μs. After that, the piston 12 decelerates under the combined action of the elastic force of the spring 9 and the pressure difference between the upper and lower sides of the piston 12, and finally falls back downward, re-pressing the second O-ring 10. At this time, the air valve is closed, and the half-width time of the piston 12 moving up and down does not exceed 500 μs.

[0009] The advantages of the present invention compared with the prior art are:

[0010] (1) Compared with the traditional solenoid valve, the heavy columnar piston (moving iron core) is replaced by a light and flat aluminum piston 12. Accordingly, the spiral coil used to drive the moving iron core is replaced by a flat disc-shaped coil 16. The stainless steel sheet 13 between the disc-shaped coil 16 and the piston 12 is only 0.03 mm, and the diffusion time of the magnetic field generated by the coil through the stainless steel sheet 13 is less than 1 microsecond.

[0011] (2) The air inlet and outlet passages of the traditional solenoid valve are both located on one side of the moving iron core. When the moving iron core is replaced with a very light piston, the resistance of the back pressure of the air inlet needs to be overcome during the closing process, resulting in a long closing time. The air valve designs the air inlet 7 above the back of the piston 12, and circulates the gas through the piston hole 11 on the piston 12, so that the air pressure difference on both sides of the piston 12 and the elastic force of the spring 9 jointly serve as the restoring force for the piston 12 to close downward, thereby reducing the movement time of the closing process.

[0012] (3) Although the air intake pulse of the present air valve is only a few hundred microseconds, the opening and closing time and air intake volume are still adjustable. By adjusting the pulse current of the disc coil 16, the height of the piston 12 can be changed, thereby changing the movement time of the piston 12 opening and closing and the air intake volume. In a traditional solenoid valve, the moving iron core will be directly adsorbed on the static iron core wrapped with the spiral coil under the action of electromagnetic force, so the opening height of the moving iron core is fixed.

[0013] (4) The disc-shaped coil 16 of the gas valve is isolated outside the gas chamber by a stainless steel sheet 13. After testing, the gas valve can be used for pulse intake of flammable and explosive gases such as hydrogen, and can withstand a gas working pressure exceeding 0.3Mpa. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a cross-sectional schematic diagram of the high-speed pulse gas valve of the present invention;

[0015] Figure 2 This is a schematic diagram of the appearance of the high-speed pulse gas valve of the present invention;

[0016] Figure 3 It is an open-hole air valve used to measure the piston's rebound time;

[0017] Figure 4 The light intensity measured by the photodetector changes with time at different discharge voltages;

[0018] Figure 5 It is the relationship between the air intake volume of the valve and the capacitor discharge voltage.

[0019] The meanings of the reference numerals in the figure are: 1-handle; 2-upper valve stem; 3-upper housing; 4-first O-ring; 5-ball; 6-air chamber housing; 7-air inlet; 8-spring fixing seat; 9-spring; 10-second O-ring; 11-piston hole; 12-piston; 13-stainless steel sheet; 14-third O-ring; 15-fourth O-ring; 16-disc coil; 17-lead; 18-valve body; 19-fifth O-ring; 20-docking flange; 21-lower valve stem; 22-terminal. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] The present invention discloses a high-speed electromagnetic pulse gas valve device, wherein a cavity is provided between a valve body 18 and an air chamber housing 6 as an air chamber, an air inlet 7 is used to introduce working gas into the cavity, and a disc-shaped piston 12 is provided in the cavity which can move up and down, and the material of the piston 12 is aluminum to reduce its weight. Under the action of a spring 9, the piston 12 is pressed on a second O-ring 10 at the top of a lower valve stem 21, thereby disconnecting the air path between the air chamber and the lower valve stem 21. The tightness of the spring 9 is determined by the up and down position of the spring fixing seat 8. By rotating the handle 1, the upper valve stem 2 is driven to rotate in and out along the threaded channel of the upper housing 3, and the up and down position of the spring fixing seat 8 can be adjusted. The ball 5 is used to reduce the friction between the upper valve stem 2 and the spring fixing seat 8 during rotation, and the first O-ring 4 is used to seal the gap between the upper valve stem 2 and the air chamber housing 6. The disc-shaped coil 16 is installed in the groove of the valve body 18, and the groove and the external hole groove can be connected to the external terminal 22 through a lead 17. The disc-shaped stainless steel sheet 13 covers the disc-shaped coil 16, and the inner and outer sides of the stainless steel sheet 13 are compressed and sealed by the fourth O-ring 15 and the third O-ring 14 to prevent the outside air from entering the air chamber along the gap between the valve body 18 and the air chamber shell 6. The docking flange 20 is used to dock with the window of the vacuum chamber. The gas valve as a whole is screwed in along the central thread groove of the docking flange 20 with the lower valve stem 21, and the fifth O-ring 19 is compressed to achieve sealing, so as to prevent the gas from entering the vacuum chamber along the gap between the lower valve stem 21 and the docking flange 20.

[0022] The working process of the quick air valve is as follows:

[0023] The external capacitor circuit provides a single pulse current to the disc coil 16 through the terminal 22. Since the thickness of the stainless steel sheet 13 is only 0.03 mm, the magnetic field generated by the energized disc coil 16 can quickly pass through the stainless steel sheet 13, induce current on the piston 12, and bounce the lightweight aluminum piston 12 away. Figure 1 The state shown is that the piston 12 has been ejected. At this time, there is a gap between the piston 12 and the second O-ring 10, so that the gas in the air chamber flows into the channel of the lower valve stem 21 through the piston hole 11 and is sprayed into the vacuum chamber.

[0024] The disc coil 16 is a single-layer disc coil made of copper enameled wire, with inner and outer diameters of 20 mm and 42 mm respectively. The diameter of the copper enameled wire is 1 mm, and it is wound 22 times. The inductance measured when it is installed in the air valve is 5 μH, and the capacitance of the external circuit connected is 200 μF. By selecting a suitable external resistor, the discharge is an over-damped discharge, and a single pulse current with a half-width of about 100 μs is obtained. Therefore, the time for the piston 12 to be accelerated upward by the electromagnetic force is about 200 μs. After that, the piston 12 decelerates under the combined action of the elastic force of the spring 9 and the pressure difference between the upper and lower sides of the piston 12, and finally falls back downward, re-pressing the second O-ring 10. At this time, the air valve is closed, and the half-width time of the piston 12 moving up and down does not exceed 500 μs.

[0025] In order to measure the time from the opening to the closing of the gas valve, the gas valve was operated as follows: Figure 3 The modification shown. A 3 mm diameter hole is bored radially through the air chamber housing 6 and the piston 12. Figure 3 The laser is emitted from the left side. When the piston 12 is closed, the laser is blocked by the piston 12 and cannot be emitted from the right hole. When the piston 12 is bounced up, the light intensity emitted from the right side is positively correlated with the height of the piston 12 bounced up. The light intensity is measured by a photodetector at the right light outlet, and the characteristic time of the up and down movement of the piston 12 can be obtained. The test circuit is an LCR pulse discharge circuit, which uses a pulse capacitor as an energy storage capacitor to discharge the disc coil 16 in the valve, and a thyristor is used as a switch. The capacitance of the pulse capacitor is 200μF, and the voltage is set to 400-480V. The test results are as follows Figure 4 As shown, it can be seen that the height and time of the piston 12 jumping up increase with the increase of the capacitor discharge voltage. When the capacitor voltage is 480V, the time from the piston 12 jumping up to closing is about 650μs, and the half-height width time does not exceed 500μs.

[0026] The air valve is installed in a volume of 0.06m 3 , vacuum degree is less than 1×10 -4 Pa vacuum tank, the air chamber pressure of the air valve is set to 1 atmosphere, and the capacitor of the external circuit is 200μF. By changing the discharge voltage of the capacitor, the relationship between the air pressure in the vacuum tank after the air valve enters the air and the discharge voltage can be obtained as follows: Figure 5 As shown. Under the same air chamber pressure, the greater the discharge voltage, the longer the valve opening time, and the greater the intake volume. When the discharge voltage is 500V, the number of gas molecules injected is calculated to be about 2×10 19 indivual.

Claims

1. A high-speed electromagnetic pulse gas valve device, characterized in that: There is a cavity between the valve body (18) and the air chamber housing (6) as an air chamber. The air inlet (7) is used to introduce working gas into the cavity. There is a disc-shaped piston (12) in the cavity that can move up and down. The material of the piston (12) is aluminum to reduce its mass. Under the action of the spring (9), the piston (12) presses on the second O-ring (10) at the top of the lower valve stem (21), thereby disconnecting the air path between the air chamber and the lower valve stem (21). The tightness of the spring (9) is determined by the up and down position of the spring fixing seat (8). By rotating the handle (1), the upper valve stem (2) is driven to rotate in and out along the threaded channel of the upper housing (3), so as to adjust the up and down position of the spring fixing seat (8). The ball (5) is used to reduce the friction between the upper valve stem (2) and the spring fixing seat (8) during rotation. The first O-ring (4) is used to The gap between the upper valve stem (2) and the air chamber housing (6) is sealed. The disc-shaped coil (16) is installed in the groove of the valve body (18). The groove and the external hole groove are connected to the external terminal (22) through the lead wire (17). The disc-shaped stainless steel sheet (13) covers the disc-shaped coil (16). The inner and outer sides of the stainless steel sheet (13) are compressed and sealed by the fourth O-ring (15) and the third O-ring (14) to prevent the outside air from entering the air chamber along the gap between the valve body (18) and the air chamber housing (6). The docking flange (20) is used to dock with the window of the vacuum chamber. The gas valve as a whole is screwed into the central thread groove of the docking flange (20) along with the lower valve stem (21), and the fifth O-ring (19) is compressed to achieve sealing, so as to prevent the gas from entering the vacuum chamber along the gap between the lower valve stem (21) and the docking flange (20).

2. A high-speed electromagnetic pulse gas valve device according to claim 1, characterized in that: The working mode of the quick air valve is as follows: the external capacitor circuit provides a single pulse current to the disc-shaped coil (16) through the terminal (22). Since the thickness of the stainless steel sheet (13) is only 0.03 mm, the magnetic field generated by the energized disc-shaped coil (16) can quickly pass through the stainless steel sheet (13), induce current on the piston (12), and bounce the very light aluminum piston (12). At this time, there is a gap between the piston (12) and the second O-ring (10), so that the gas in the air chamber flows into the channel in the middle of the lower valve stem (21) through the piston hole (11) and sprays into the vacuum chamber; the disc-shaped coil (16) is a single-layer disc-shaped coil made of copper enameled wire, and the inner and outer diameters are respectively 20mm and 42mm, the diameter of the copper enameled wire is 1mm, and it is tightly wound 22 times. The inductance measured when installed in the air valve is 5μH, and the capacitance of the external circuit connected is 200μF. By selecting a suitable external resistor, the discharge is an over-damped discharge, and a single pulse current with a half-width of about 100μs is obtained. Therefore, the time for the piston (12) to be accelerated upward by the electromagnetic force is about 200μs. Thereafter, the piston (12) is decelerated under the combined action of the elastic force of the spring (9) and the pressure difference between the upper and lower sides of the piston (12), and finally falls back downward, re-pressing the second O circle (10). At this time, the air valve is closed, and the half-width time of the piston (12) moving up and down does not exceed 500μs.

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