CN212337634U

CN212337634U - Electromagnetic valve and rotary vane vacuum pump linkage control device

Info

Publication number: CN212337634U
Application number: CN202022144373.XU
Authority: CN
Inventors: 何晓; 王莉君; 赵庆捷
Original assignee: Hangzhou Best Gas Co ltd
Current assignee: Hangzhou Best Gas Co ltd
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2021-01-12
Anticipated expiration: 2030-09-25

Abstract

The utility model discloses a solenoid valve and rotary vane vacuum pump coordinated control device, including the mount pad, the installation pump body of mount pad, mount pad other end installation motor, the output shaft pump body of motor, the top of the pump body are equipped with the extraction opening, and protection machanism is connected to the extraction opening, and the solenoid valve is connected at protection machanism's top, and the breathing pipe is connected to the solenoid valve, and normally closed switch, the mutual series connection of solenoid valve and motor are installed at protection machanism's top. When the accident has a power failure and leads to the vacuum pump to stop, the solenoid valve directly cuts off the power supply, seal the air suction pipe in millisecond, avoid vacuum pump oil suck-back to take in breathing pipe and the steel bottle, when the vacuum pump is inside to lead to stopping because of mechanical failure, protection mechanism blocks the protection to vacuum pump oil, trigger normally closed switch simultaneously, normally closed switch disconnection for the solenoid valve will be breathed in the pipe and is sealed, realize the mechanical type linkage, avoid vacuum pump oil suck-back, the hidden danger of vacuum pump oil suck-back has been stopped to two kinds of linkage modes of vacuum pump and solenoid valve.

Description

Electromagnetic valve and rotary vane vacuum pump linkage control device

Technical Field

The utility model relates to a vacuum pump technical field specifically is solenoid valve and sliding vane rotary vacuum pump coordinated control device.

Background

The steel cylinder is a steel cylinder for storing high-pressure oxygen, coal gas, petroleum liquefied gas and the like, the safety performance of gas storage can be improved, the steel cylinder needs to be vacuumized before being filled with stored gas, the steel cylinder is connected with an exhaust tube through a vacuum pump in the prior vacuumizing mode, the interior of the steel cylinder is vacuumized, when the vacuum pump stops working suddenly due to abnormal conditions such as power failure and the like in the vacuumizing process, oil pumped by the vacuum pump is sucked back into the vacuum steel cylinder due to the suction force of the vacuum steel cylinder, the steel cylinder is polluted, potential safety hazards and quality problems can be caused if the steel cylinder enters a filling link, a check valve is arranged on the exhaust tube in the prior mode for preventing the oil pumped by the vacuum pump, however, the interior of the check valve is usually sealed automatically through an elastic element, and during the vacuumizing, the power of the vacuum pump needs to overcome the elastic force of the elastic element of the check valve, and the internal channel of the one-way valve is small, which affects the vacuum pumping capability of the vacuum pump, so that a linkage control device of the electromagnetic valve and the rotary vane vacuum pump is provided for solving the problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a solenoid valve and sliding vane vacuum pump coordinated control device to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme: solenoid valve and rotary vane vacuum pump coordinated control device, including the mount pad, the one end outer wall fixed mounting pump body of mount pad, the other end outer wall fixed mounting motor of mount pad, the output shaft of motor and the input shaft of the pump body rotate and stretch into the mount pad inner chamber and pass through the coupling joint, the top of the pump body is equipped with the extraction opening, one side outer wall of the pump body is equipped with the gas vent, the gas vent passes through the flange joint blast pipe, the extraction opening passes through flange joint protection mechanism's bottom, the one end of solenoid valve is connected at protection mechanism's top, the other end fixed connection breathing pipe of solenoid valve, normally closed switch is installed at protection mechanism's top, the series connection each other of normally closed switch, solenoid valve and motor.

In a preferred embodiment, the handle is fixedly arranged at the top of the mounting seat, the supporting base is arranged at the bottom of the mounting seat, and the rubber pad is fixedly arranged at the bottom of the supporting base.

The air suction pipe is provided with the pressure gauge, the valve body of the electromagnetic valve is a stainless steel valve body, sealing pieces of the electromagnetic valve are high-temperature-resistant PTFE packing gaskets, corrosion-resistant materials are used as materials of the valve body of the electromagnetic valve and the sealing pieces, the structure is simple, the heating evacuation use can be met, the action of the electromagnetic valve is not influenced, the requirement of residual gas treatment of most gas steel cylinders is met, and the service life of the electromagnetic valve is not influenced.

An embodiment of preferred, protection machanism includes stand pipe and back flow, integrated into one piece is equipped with the honeycomb duct between the bottom of stand pipe and the top of back flow, flange joint extraction opening is passed through to the bottom of back flow, the inner chamber of stand pipe slides and cup joints the kicking block, a plurality of locating pieces of outer wall fixed mounting of kicking block, the inner wall of the stand pipe of closely laminating of the outer wall of locating piece, adjacent locating piece and the interior wall of stand pipe form the circulation chamber, the flange joint top cap is passed through at the top of stand pipe, the one end of the top fixed mounting connecting pipe of top cap, the other end of connecting pipe passes through the valve body one end of helicitic texture connection solenoid valve, the top middle part fixed mounting of kicking block is sealed, sealed the bottom to the connecting pipe, fixed mounting normally closed switch on the top cap in.

In an embodiment of the present invention, the flow guide tube is a hollow circular truncated cone structure with a large top and a small bottom, the large diameter end of the flow guide tube is connected to the guide tube, the small diameter end of the flow guide tube is connected to the return tube, the floating block and the positioning block are both hollow structures, the floating block is a cylindrical structure at the top, the circular truncated cone structure with a large top and a small bottom is at the bottom, and the positioning blocks are uniformly distributed along the circumferential direction of the floating block.

In a preferred embodiment, the inner diameter of the top cover is equal to the diameter of the top of the floating block, the distance from the top surface of the floating block to the top surface of the positioning block is greater than the depth of the inner cavity of the top cover, and the sealing gasket is in a circular truncated cone structure with a small upper part and a large lower part.

Preferably, the normally closed switch includes a housing, the housing is fixedly mounted at the top of the protection mechanism, the housing is slidably connected with an insulating plate in a clamping manner, a moving contact is fixedly mounted at the bottom of the insulating plate, a fixed contact is fixedly mounted at the bottom of an inner cavity of the housing, a push rod is fixedly connected to the middle of the bottom surface of the insulating plate, the push rod slidably penetrates through the housing and extends into the protection mechanism, a pressure spring is mounted between the top of the insulating plate and the top of the inner cavity of the housing, a first terminal is fixedly sleeved at the bottom of a side wall of the housing, the first terminal is fixedly connected with the fixed contact, a second terminal is fixedly sleeved at the top of the housing, a connecting wire is fixedly connected at the bottom of the second.

In an embodiment of the present invention, the fixed contact and the moving contact are of a copper ring structure, the push rod penetrates through inner cavities of the fixed contact and the moving contact, the pressure spring is always in a compressed state, and an outer wall of the pressure spring is attached to an inner wall of the housing.

Compared with the prior art, the beneficial effects of the utility model are that:

1. at ordinary times, the floating block and the positioning block are positioned at the bottom of the guide pipe under the action of gravity, the internal circulation space of the protection mechanism is large, the vacuumizing is convenient, the power of a vacuum pump is not required to be additionally consumed, so that the pipeline is smooth, and the vacuumizing capacity is not influenced;

2. when the motor has power failure or the external power supply has power failure, the electromagnetic valve is directly linked to be powered off and closed, so that the air suction pipe is closed within milliseconds, the vacuum pump oil is prevented from being sucked backwards, when the pump body has mechanical failure and the like, the protective mechanism is closed, the normally closed switch is opened, and the rotary vane vacuum pump linked with the electromagnetic valve is matched, so that a channel between the vacuum steel cylinder and the vacuum pump can be immediately blocked under the condition of accidental pump stop, the hidden danger of sucking backwards of the vacuum pump oil is avoided, and the cleanness and the safety of the interior of the steel cylinder are improved;

3. in the closed time quantum of solenoid valve linkage, the stand pipe is saved the vacuum pump oil of slight suck-back, avoids receiving the pollution in the suction pipe, and the fault repair back, and during the vacuum pump operation, honeycomb duct and back flow are convenient for vacuum pump oil and flow back to the vacuum pump in, and each part of protection machanism passes through flange joint, and the dismouting is convenient, conveniently washs operation such as inside.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of a cross-sectional structure of the middle protection mechanism of the present invention;

fig. 3 is a schematic structural view of a section of the normally closed switch of the present invention;

fig. 4 is a schematic diagram of the connection circuit of the middle electromagnetic valve of the present invention.

In the figure: 1. a mounting seat; 2. a pump body; 3. a motor; 4. an air extraction opening; 5. an exhaust port; 6. an exhaust pipe; 7. a protection mechanism; 71. a guide tube; 72. a return pipe; 73. a flow guide pipe; 74. floating blocks; 75. positioning blocks; 76. a flow-through chamber; 77. a top cover; 78. a connecting pipe; 79. a gasket; 8. an electromagnetic valve; 9. a normally closed switch; 91. a housing; 92. an insulating plate; 93. a moving contact; 94. static contact; 95. a top rod; 96. a first terminal; 97. a pressure spring; 98. a second terminal; 99. a connecting wire; 10. an air intake duct; 11. and a pressure gauge.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-4, the present invention provides a technical solution: solenoid valve and rotary vane vacuum pump coordinated control device, including mount pad 1, the one end outer wall fixed mounting pump body 2 of mount pad 1, the other end outer wall fixed mounting motor 3 of mount pad 1, the output shaft of motor 3 and the input shaft of the pump body 2 rotate and stretch into 1 inner chamber of mount pad and pass through the coupling joint, the top of the pump body 2 is equipped with extraction opening 4, one side outer wall of the pump body 2 is equipped with gas vent 5, gas vent 5 passes through flange joint exhaust pipe 6, extraction opening 4 passes through the bottom of flange joint protection mechanism 7, the one end of solenoid valve 8 is connected at the top of protection mechanism 7, the other end fixed connection breathing pipe 10 of solenoid valve 8, normally closed switch 9 is installed at the top of protection mechanism 7, normally closed switch 9, the mutual series connection of solenoid valve 8 and motor 3. The motor 3 and the pump body 2 form a rotary vane vacuum pump, so that gas in the steel cylinder is pumped through the air suction pipe 10 for vacuum pumping, the electromagnetic valve 8 is in linkage control with the motor 3, when the vacuum pump stops due to unexpected power failure, the electromagnetic valve 8 is directly powered off, thereby sealing the air suction pipe 10 in milliseconds, avoiding the vacuum pump oil from being sucked back into the air suction pipe 10 and the steel cylinder, when the vacuum pump stops due to mechanical failure in the vacuum pump, the protection mechanism 7 blocks and protects the oil of the vacuum pump, and simultaneously the protection mechanism 7 triggers the normally closed switch 9, the normally closed switch 9 is switched off, thereby the electromagnetic valve 8 seals the air suction pipe 10, the mechanical linkage is realized, the oil suck-back of the vacuum pump is avoided, the vacuum pump and the electromagnetic valve 8 are in two linkage modes, the channel between the vacuum steel cylinder and the vacuum pump can be immediately blocked under the condition of accidental pump stop, and the hidden danger of oil suck-back of the vacuum pump is avoided.

The top fixed mounting handle of mount pad 1, the removal installation of the vacuum pump of being convenient for, the bottom of mount pad 1 is equipped with the support base, and supports the bottom fixed mounting rubber pad of base.

Install manometer 11 on breathing pipe 10 for detect gas pressure in the steel bottle, solenoid valve 8's valve body is stainless steel valve body, solenoid valve 8's sealing member is high temperature resistance tetrafluoro packing gasket, corrosion resistance's material is as solenoid valve body material and sealing member material, simple structure can satisfy the heating and manage to find time the use, does not influence the action of solenoid valve, with the requirement of the surplus gas processing of satisfying the most gaseous steel bottle of splendid attire, does not influence the life of solenoid valve.

The protection mechanism 7 comprises a guide pipe 71 and a return pipe 72, a guide pipe 73 is integrally formed between the bottom of the guide pipe 71 and the top of the return pipe 72, the bottom of the return pipe 72 is connected with the air suction opening 4 through a flange, an inner cavity of the guide pipe 71 is slidably sleeved with a floating block 74, a plurality of positioning blocks 75 are fixedly installed on the outer wall of the floating block 74, the outer wall of each positioning block 75 is tightly attached to the inner wall of the guide pipe 71, a circulation cavity 76 is formed between every two adjacent positioning blocks 75 and the inner wall of the guide pipe 71, the top of the guide pipe 71 is connected with a top cover 77 through a flange, one end of a connecting pipe 78 is fixedly installed on the top of the top cover 77, the other end of the connecting pipe 78 is connected with one end of a valve body of the electromagnetic valve 8 through a threaded structure, a sealing gasket 79 is fixedly installed in the middle of the top of the floating, the large-diameter end of the guide pipe 73 is connected with the guide pipe 71, the small-diameter end is connected with the return pipe 72, the floating block 74 and the positioning block 75 are both hollow structures, the top of the floating block 74 is a cylindrical structure, the bottom of the floating block 74 is a circular truncated cone structure with a large top and a small bottom, the positioning blocks 75 are uniformly distributed along the circumferential direction of the floating block 74, the floating block 74 is positioned through the positioning blocks 75 so as to be coaxial with the guide pipe 71, when the vacuum pump operates at ordinary times, the bottom of the positioning block 75 is supported on the inner wall of the top of the guide pipe 73, gas in the air suction pipe 10 enters the top cover 77 through the connecting pipe 78 and then flows through the flow-through cavity 76, and the floating block 74 and the positioning block 75 are positioned at the bottom of the guide pipe 71 under the action of gravity, so that the power of the vacuum pump is not required to be additionally consumed to lead to the smooth management, the vacuum pumping, the gasket 79 seals the connecting tube 78 to prevent the vacuum pump oil from sucking back into the suction pipe 10 and the cylinder, and the slider 74 slides up to trigger the normally closed switch 9, thereby closing the solenoid valve 8.

Further, the guide pipe 71 stores slightly suck-back vacuum pump oil, after fault repair, when the vacuum pump operates, the guide pipe 73 and the return pipe 72 facilitate return of the vacuum pump oil to the vacuum pump, and each part of the protection mechanism 7 is connected through a flange, so that the protection mechanism is convenient to disassemble and assemble, and is convenient to clean the inside.

The internal diameter of top cap 77 equals the top diameter of floating block 74, and the distance of the top surface of floating block 74 to the top surface of locating piece 75 is greater than the inner chamber degree of depth of top cap 77, ensures that floating block 74 can stretch into in the top cap 77 when shifting up, is convenient for trigger normally closed switch 9, and sealed pad 79 is big end down's round platform structure, is convenient for seal connecting pipe 78.

The normally closed switch 9 comprises a shell 91, the shell 91 is fixedly arranged at the top of the protection mechanism 7, an insulating plate 92 is slidably clamped in the shell 91, a moving contact 93 is fixedly arranged at the bottom of the insulating plate 92, a fixed contact 94 is fixedly arranged at the bottom of an inner cavity of the shell 91, a push rod 95 is fixedly connected to the middle of the bottom surface of the insulating plate 92, the push rod 95 slidably penetrates through the shell 91 and extends into the protection mechanism 7, a pressure spring 97 is arranged between the top of the insulating plate 92 and the top of the inner cavity of the shell 91, a first terminal 96 is fixedly sleeved at the bottom of a side wall of the shell 91, the first terminal 96 is fixedly connected with the fixed contact 94, a second terminal 98 is fixedly sleeved at the top of the shell 91, a connecting wire 99 is fixedly connected at the bottom of the second terminal 98, the other end of the connecting wire 99 fixedly penetrates through, the compression spring 97 is always in a compressed state, the outer wall of the compression spring 97 is attached to the inner wall of the shell 91, the shell 91 is fixed to the top of the top cover 77, the ejector rod 95 extends into the inner cavity of the top cover 77, at ordinary times, the pressure of the compression spring 97 enables the insulation plate 92 to be located at the bottom of the inner cavity of the shell 91, the movable contact 93 is tightly attached and electrically connected with the static contact 94, at this time, the first terminal 96 is electrically connected with one end of a power line of the motor 3 through a wire, the second terminal 98 is electrically connected with one end of a power line of the electromagnetic valve 8, the other ends of the power lines of the motor 3 and the electromagnetic valve 8 are respectively connected with an external power supply (shown in figure 4), at ordinary times, the movable contact 93 is attached to the static contact 94, the normally closed switch 9 is closed to enable a circuit to be smooth, when the circuit, when the moving contact 93 is separated from the fixed contact 94, the circuit is also opened, and the electromagnetic valve 8 is closed in a linkage manner, so that the vacuum pump oil is completely prevented from being sucked back into the air suction pipe 10 and the steel cylinder.

The working principle is as follows: when the utility model is used, the motor 3 and the pump body 2 form a rotary vane vacuum pump, the air suction pipe 10 is connected with the steel cylinder, the first terminal 96 is electrically connected with one end of the power line of the motor 3 through a wire, the second terminal 98 is electrically connected with one end of the power line of the electromagnetic valve 8, the other ends of the power lines of the motor 3 and the electromagnetic valve 8 are respectively connected with an external power supply, the pressure of the pressure spring 97 at ordinary times enables the insulating plate 92 to be positioned at the bottom of the inner cavity of the shell 91, the moving contact 93 and the static contact 94 are kept to be tightly attached and electrically connected, at the moment, the first terminal 96 is electrically connected with one end of the power line of the motor 3 through a wire, the series circuit between the normally closed switch 9, the electromagnetic valve 8 and the motor 3 is unblocked, when the vacuum is pumped, the bottom of the positioning block 75 is supported on the inner, at this time, the floating block 74 and the positioning block 75 are located at the bottom of the guide tube 71 under the action of gravity, so that the pipeline is smooth without consuming extra power of the vacuum pump, and the vacuum pumping capacity is not affected, when the power failure of the motor 3 or the power failure of an external power supply occurs, the electromagnetic valve 8 is directly linked and switched off and closed, so that the air suction tube 10 is closed within milliseconds, the vacuum pump oil is prevented from being sucked backwards, if the mechanical failure of the pump body 2 and the like causes the stop, the vacuum pump oil is slightly sucked backwards into the guide tube 71, the floating block 74 slides upwards along the guide tube 71 under the action of buoyancy and the vacuum suction force of the steel cylinder, the sealing gasket 79 seals the connecting tube 78, so that the vacuum pump oil is prevented from being sucked backwards into the air suction tube 10 and the steel cylinder, meanwhile, the floating block 74 slides upwards to push the ejector rod 95, the ejector rod 95 pushes the insulating plate 92 upwards, so that, stop completely in vacuum pump oil suck-back 10 and the steel bottle, improve the inside cleanness of steel bottle and security, and the stand pipe 71 is saved the vacuum pump oil of slight suck-back, after the fault repair, during the vacuum pump operation, honeycomb duct 73 and back flow 72 are convenient for vacuum pump oil to flow back in the vacuum pump, and each part of protection machanism 7 passes through flange joint, and the dismouting is convenient, conveniently washs operation such as inside.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. Solenoid valve and sliding vane vacuum pump coordinated control device, including mount pad (1), its characterized in that: a pump body (2) is fixedly arranged on the outer wall of one end of the mounting seat (1), a motor (3) is fixedly arranged on the outer wall of the other end of the mounting seat (1), the output shaft of the motor (3) and the input shaft of the pump body (2) extend into the inner cavity of the mounting seat (1) in a rotating way and are connected through a coupling, the top of the pump body (2) is provided with an air suction opening (4), the outer wall of one side of the pump body (2) is provided with an air exhaust opening (5), the exhaust port (5) is connected with an exhaust pipe (6) through a flange, the air pumping port (4) is connected with the bottom of the protection mechanism (7) through a flange, the top of the protection mechanism (7) is connected with one end of an electromagnetic valve (8), the other end of the electromagnetic valve (8) is fixedly connected with an air suction pipe (10), normally closed switch (9) are installed at the top of protection machanism (7), establish ties each other of normally closed switch (9), solenoid valve (8) and motor (3).

2. The solenoid valve and rotary vane vacuum pump coordinated control device according to claim 1, characterized in that: the handle is fixedly installed at the top of the installation seat (1), the supporting base is arranged at the bottom of the installation seat (1), and the rubber pad is fixedly installed at the bottom of the supporting base.

3. The solenoid valve and rotary vane vacuum pump coordinated control device according to claim 1, characterized in that: the air suction pipe (10) is provided with a pressure gauge (11), the valve body of the electromagnetic valve (8) is a stainless steel valve body, and sealing elements of the electromagnetic valve (8) are high-temperature-resistant PTFE packing gaskets.

4. The solenoid valve and rotary vane vacuum pump coordinated control device according to claim 1, characterized in that: the protection mechanism (7) comprises a guide pipe (71) and a return pipe (72), a guide pipe (73) is integrally formed between the bottom of the guide pipe (71) and the top of the return pipe (72), the bottom of the return pipe (72) is connected with the air suction opening (4) through a flange, a floating block (74) is sleeved in an inner cavity of the guide pipe (71) in a sliding mode, a plurality of positioning blocks (75) are fixedly installed on the outer wall of the floating block (74), the outer wall of each positioning block (75) is tightly attached to the inner wall of the guide pipe (71), a circulation cavity (76) is formed between each adjacent positioning block (75) and the inner wall of the guide pipe (71), the top of the guide pipe (71) is connected with a top cover (77) through a flange, one end of a connecting pipe (78) is fixedly installed on the top of the top cover (77), and the other end of the connecting pipe (78, the top middle part fixed mounting of floater (74) seals up (79), sealed the bottom just to connecting pipe (78) of packing up (79), fixed mounting normally closed switch (9) are gone up to top cap (77) in connecting pipe (78) outside.

5. The solenoid valve and rotary vane vacuum pump coordinated control device according to claim 4, characterized in that: honeycomb duct (73) are big-end-up's hollow round platform structure, and the big footpath end of honeycomb duct (73) connects stand pipe (71), and back flow (72) are connected to the path end, floating block (74) and locating piece (75) are hollow structure, floating block (74) are the top and are the cylinder structure, and the bottom is big-end-up's round platform structure, locating piece (75) are along floating block (74) circumferencial direction evenly distributed.

6. The solenoid valve and rotary vane vacuum pump coordinated control device according to claim 4, characterized in that: the inner diameter of the top cover (77) is equal to the diameter of the top of the floating block (74), the distance from the top surface of the floating block (74) to the top surface of the positioning block (75) is greater than the depth of the inner cavity of the top cover (77), and the sealing gasket (79) is of a round table structure with a small upper part and a large lower part.

7. The solenoid valve and rotary vane vacuum pump coordinated control device according to claim 1, characterized in that: the normally closed switch (9) comprises a shell (91), the shell (91) is fixedly installed at the top of a protection mechanism (7), an insulating plate (92) is clamped in the shell (91) in a sliding mode, a moving contact (93) is fixedly installed at the bottom of the insulating plate (92), a static contact (94) is fixedly installed at the bottom of an inner cavity of the shell (91), an ejector rod (95) is fixedly connected to the middle of the bottom surface of the insulating plate (92), the ejector rod (95) penetrates through the shell (91) in a sliding mode and extends into the protection mechanism (7), a pressure spring (97) is installed between the top of the insulating plate (92) and the top of the inner cavity of the shell (91), a first terminal (96) is fixedly sleeved at the bottom of the side wall of the shell (91), the first terminal (96) is fixedly connected with the static contact (94), a second terminal (98) is fixedly sleeved at the top of the shell (91), and, and the other end of the connecting wire (99) is fixedly penetrated through the insulating plate (92) and electrically connected with the moving contact (93).

8. The solenoid valve and rotary vane vacuum pump coordinated control device according to claim 7, characterized in that: the fixed contact (94) and the moving contact (93) are of a copper circular ring structure, the ejector rod (95) penetrates through inner cavities of the fixed contact (94) and the moving contact (93), the pressure spring (97) is always in a compression state, and the outer wall of the pressure spring (97) is attached to the inner wall of the shell (91).