CN220268589U

CN220268589U - Blanking dome valve

Info

Publication number: CN220268589U
Application number: CN202320913078.7U
Authority: CN
Inventors: 范君峰; 丁建学; 李惠安; 杨晓东; 王龙; 辛文斌; 陈天池; 白瑞民; 黄孔甫; 张福厚
Original assignee: Baotou No3 Thermal Power Plant Of North United Power Co ltd
Current assignee: Baotou No3 Thermal Power Plant Of North United Power Co ltd
Priority date: 2023-04-20
Filing date: 2023-04-20
Publication date: 2023-12-29
Anticipated expiration: 2033-04-20

Abstract

The utility model relates to a blanking dome valve, which comprises a dome valve, a rotary cylinder, an air bag, an electromagnetic valve and a machine control valve; the dome valve can be arranged at a feed inlet of the ash bucket; the rotary cylinder is connected with the dome valve and used for driving the dome valve to open and close in a rotating way; the air bag is arranged below the dome valve and is used for sealing the dome valve; the electromagnetic valve is communicated with one side of the rotary cylinder and is used for providing power for the rotary cylinder; the electromagnetic valve is also communicated with the air bag and is used for inflating the air bag; the electromagnetic valve is communicated with the air bag through a mechanical control valve, and the mechanical control valve is used for enabling the electromagnetic valve to be communicated with or disconnected from the air bag; a first quick-discharge valve is arranged between the machine control valve and the air bag and is used for discharging compressed air in the air bag. When the dome valve is opened, compressed air in the air bag can be discharged to the outside through the first quick exhaust valve so as to thoroughly separate the air bag from other parts, even if the air bag is damaged due to ash dropping scouring, the ash inlet condition of other parts cannot be caused, and the defect that the blanking dome valve fails due to ash inlet is avoided.

Description

Blanking dome valve

Technical Field

The utility model relates to the technical field of dust removal, in particular to a blanking dome valve.

Background

After the flue gas generated by the boiler is subjected to electric dust removal treatment, the generated ash can be stored in bin pumps, and each bin pump then puts the ash into a conveying pipeline through a blanking dome valve, and the ash is conveyed to an ash warehouse by using compressed air as power.

The existing blanking dome valve generally comprises components such as an air bag, a pressure switch, a machine control valve, an electromagnetic valve and the like. Because the gasbag is very easy to appear damaging after being erodeed by the falling ash in the use, lead to under the effect of the compressed air of carrying, ash can get into pressure switch or machine accuse valve along the pipeline to the condition of stifled ash or hardening appears. If ash enters the pressure switch, the signal is easy to be sent out by mistake, and the control of workers on the ash conveying process is affected. If ash enters the machine control valve, when the on-off switch of the machine control valve is switched, the ash in the machine control valve can be carried into the electromagnetic valve along with compressed air, so that the electromagnetic valve is blocked, the blanking dome valve cannot be normally opened and closed, and the blanking dome valve is in fault.

Therefore, the existing blanking dome valve is extremely easy to cause abnormal work due to dust entering of components.

Disclosure of Invention

The utility model provides a blanking dome valve, which aims to solve the problem that the conventional blanking dome valve is very easy to cause abnormal work due to dust entering of components.

The utility model provides a blanking dome valve for realizing the purpose, which comprises: the dome valve can be arranged at a feed inlet of the ash bucket; the rotary cylinder is connected with the dome valve and used for driving the dome valve to open and close in a rotating mode; the air bag is arranged below the dome valve and is used for sealing the dome valve; the electromagnetic valve is communicated with one side of the rotary cylinder and is used for providing power for the rotary cylinder; the electromagnetic valve is also communicated with the air bag and is used for inflating the air bag; the electromagnetic valve is communicated with the air bag through the mechanical control valve, and the mechanical control valve is used for enabling the electromagnetic valve to be communicated with or disconnected from the air bag; a first quick-discharge valve is arranged between the machine control valve and the air bag and is used for discharging compressed air in the air bag.

In some embodiments, the blanking dome valve further comprises: the second quick-discharge valve is communicated with one side of the rotary cylinder; the second quick-release valve is also communicated with the machine control valve.

In some embodiments, a first air guide port is arranged on the electromagnetic valve and is connected with one side of the rotary cylinder through a first air source pipe; the second quick exhaust valve is provided with a second air guide port which is connected with the other side of the rotary cylinder through a second air source pipe.

In some embodiments, a third air guide port is further arranged on the electromagnetic valve and is connected with an air inlet of the machine control valve through a third air source pipe; the first quick exhaust valve is provided with a fourth air guide port and a fifth air guide port, the exhaust port of the mechanical control valve is connected with the fourth air guide port through a fourth air source pipe, and the fifth air guide port is connected with the air inlet of the air bag through a fifth air source pipe.

In some embodiments, a sixth air guide port is further arranged on the second quick exhaust valve, the sixth air guide port is connected with a sixth air source pipe, and one end, far away from the sixth air guide port, of the sixth air source pipe is connected with a fourth air source pipe through a three-way connecting assembly.

In some embodiments, the blanking dome valve further comprises: the connecting port of the pressure switch is connected with a seventh air source pipe, and one end of the seventh air source pipe, which is far away from the connecting port, is connected with a fourth air source pipe through another three-way connecting component.

In some embodiments, the first quick drain valve and the second quick drain valve are both pneumatically controlled quick drain valves.

In some embodiments, the output end of the rotary cylinder is provided with a rotary shaft, and the end of the rotary shaft remote from the rotary cylinder is connected with the dome valve.

In some embodiments, the machine control valve is provided with an on-off switch, and the on-off switch is a non-self-locking switch; the rotary shaft is provided with a compression bar, and one end of the compression bar far away from the rotary shaft is opposite to the on-off switch.

The utility model has the beneficial effects that:

when the blanking dome valve is opened under the action of the air cylinder, compressed air in the air bag can be discharged to the outside through the first quick-release valve, so that the air bag is thoroughly separated from other parts. Even if the air bag is damaged due to ash dropping scouring, other parts cannot be caused to enter ash, and the fault of the blanking dome valve caused by ash entering is avoided.

Drawings

FIG. 1 is a schematic diagram of some embodiments of a blanking dome valve of the present utility model;

FIG. 2 is a structural side view of some embodiments of the rotary shaft and the mechanically controlled valve shown in FIG. 1.

In the drawings, 100, dome valve; 200. a rotary cylinder; 210. a rotation shaft; 211. a compression bar; 300. an air bag; 400. an electromagnetic valve; 500. a mechanically controlled valve; 510. an on-off switch; 600. a first quick drain valve; 700. a second quick-release valve; 800. and a pressure switch.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments.

Examples of the embodiments are illustrated in the accompanying drawings, wherein like or similar symbols indicate like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present utility model and should not be construed as limiting the utility model.

In the description of the present utility model, it should be understood that the terms "top," "bottom," "inner," "outer," "axis," "circumferential," and the like indicate an orientation or a positional relationship based on that shown in the drawings, and are merely for convenience in describing the present utility model or simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," "engaged," "hinged," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Referring to fig. 1 and 2, a blanking dome valve includes a dome valve 100, a rotary cylinder 200, an airbag 300, a solenoid valve 400, and a mechanical control valve 500. The dome valve 100 may be disposed at the feed inlet of the ash bucket. The rotary cylinder 200 is connected to the dome valve 100, and is used for rotationally driving the dome valve 100 to open and close. The airbag 300 is provided below the dome valve 100 for sealing the dome valve 100. The solenoid valve 400 communicates with one side of the rotary cylinder 200 for powering the rotary cylinder 200. Solenoid valve 400 is also in communication with bladder 300 for inflating bladder 300. The solenoid valve 400 communicates with the airbag 300 through the pilot operated valve 500, and the pilot operated valve 500 is used to connect or disconnect the solenoid valve 400 to or from the airbag 300. A first quick-discharge valve 600 is provided between the mechanical control valve 500 and the airbag 300, and the first quick-discharge valve 600 is used for discharging the compressed air in the airbag 300.

Specifically, the dome valve 100 is connected to the output end of the rotary cylinder 200, and the dome valve 100 is rotated by the rotary cylinder 200 to achieve the effect of opening or closing the dome valve 100. The bottom of the dome valve 100 is provided with a balloon 300, and when the dome valve 100 is closed, the balloon 300 can be inflated to fill the gap of the dome valve 100, thereby achieving a sealing effect. The solenoid valve 400 is connected with the rotary cylinder 200 to transmit compressed air to the inside of the rotary cylinder 200, so that the output end of the rotary cylinder 200 drives the dome valve 100 to rotate, thereby achieving the effect of controlling the dome valve 100 to be opened or closed, or the solenoid valve 400 is used for discharging the compressed air in the rotary cylinder 200, so that the output end of the rotary cylinder 200 drives the dome valve 100 to rotate reversely, thereby achieving the effect of controlling the dome valve 100 to be closed or opened. The electromagnetic valve 400 is connected with the air bag 300 through the mechanical control valve 500, and compressed air is conveyed into the air bag 300, so that the air bag 300 is inflated to fill the gap of the dome valve 100, and the electromagnetic valve 400 and the air bag 300 can be communicated or the electromagnetic valve 400 and the air bag 300 can be disconnected through the mechanical control valve 500, so that the electromagnetic valve 400 can be inflated into the air bag 300 according to the requirement. The first quick-release valve 600 is arranged between the air-control valve 500 and the air-control valve 300, the air-control valve 500 and the electromagnetic valve 400 are blocked by the first quick-release valve 600, so that the air in the air-control valve 300 can be directly discharged through the first quick-release valve 600, the situation that the air in the air-control valve 300 carries fine dust to enter the air-control valve 500 and finally the fine dust enters the electromagnetic valve 400 is avoided, and the electromagnetic valve 400 is caused to fail.

The specific workflow is that, when the electromagnetic valve 400 is powered on, the electromagnetic valve 400 will convey compressed air to the inside of the revolving cylinder 200, so that the output end of the revolving cylinder 200 drives the dome valve 100 to rotate clockwise, and then the dome valve 100 is opened, meanwhile, because the air bag 300 does not need to be inflated, the machine control valve 500 is closed by a worker, the compressed air conveyed to the air bag 300 by the electromagnetic valve 400 is cut off, and the compressed air in the air bag 300 will be discharged to the outside through the first quick discharge valve 600 because the compressed air is not conveyed to the air bag 300, so that the compressed air in the air bag 300 is prevented from carrying fine ash to enter the machine control valve 500 and the electromagnetic valve 400, thereby causing faults. When the electromagnetic valve 400 is powered off, the compressed air in the rotary cylinder 200 is discharged through the electromagnetic valve 400, so that the output end of the rotary cylinder 200 drives the dome valve 100 to rotate anticlockwise, and then the dome valve 100 is closed, and meanwhile, the air gap of the dome valve 100 is required to be filled by the expansion of the air bag 300, and the machine control valve 500 can be opened by a worker, so that the electromagnetic valve 400 conveys the compressed air into the air bag 300, and the air gap of the dome valve 100 is filled.

In some embodiments of the present utility model, a second quick-drain valve 700 is also included. The second quick discharge valve 700 communicates with one side of the rotary cylinder 200. The second quick drain valve 700 is also in communication with the pilot operated valve 500. When the electromagnetic valve 400 is powered on, the electromagnetic valve 400 can convey compressed air to one side of the rotary cylinder 200, meanwhile, compressed air is discharged to the outside through the second quick-release valve 700 at the other side of the rotary cylinder 200, so that the rotary cylinder 200 can work more smoothly, and the output end of the rotary cylinder 200 drives the dome valve 100 to rotate more stably. When the electromagnetic valve 400 is powered off, the compressed air in the rotary cylinder 200 can be discharged from one side through the electromagnetic valve 400, meanwhile, the compressed air conveyed by the electromagnetic valve 400 can reach the second quick-release valve 700 through the machine control valve 500, and then is conveyed to the other side of the rotary cylinder 200 through the second quick-release valve 700, so that the rotary cylinder 200 can work more smoothly, and the output end of the rotary cylinder 200 drives the dome valve 100 to rotate more stably.

In some embodiments of the present utility model, the solenoid valve 400 is provided with a first air guide port, and the first air guide port is connected to one side of the rotary cylinder 200 through a first air source pipe. The second quick exhaust valve 700 is provided with a second air guide port, and the second air guide port is connected with the other side of the rotary cylinder 200 through a second air source pipe. One end of the first air source pipe is connected with one side of the rotary cylinder 200, and the other end is connected with a first air guide port of the electromagnetic valve 400, so that the electromagnetic valve 400 can convey compressed air to one side of the rotary cylinder 200 through the first air source pipe, or the compressed air in the rotary cylinder 200 can reach the electromagnetic valve 400 from one side through the first air source pipe to be discharged. One end of the second air source pipe is connected with the other side of the rotary cylinder 200, and the other end of the second air source pipe is connected with a second air guide port of the second quick-release valve 700, so that compressed air reaching the second quick-release valve 700 can be conveyed to the other side of the rotary cylinder 200 through the second air source pipe, or compressed air in the rotary cylinder 200 can be discharged from the other side through the second air source pipe to the second quick-release valve 700.

In some embodiments of the present utility model, a third air guide port is further provided on the solenoid valve 400, and the third air guide port is connected to the air inlet of the mechanically controlled valve 500 through a third air source pipe. The first quick-release valve 600 is provided with a fourth air guide port and a fifth air guide port, the air outlet of the mechanical control valve 500 is connected with the fourth air guide port through a fourth air source pipe, and the fifth air guide port is connected with the air inlet of the air bag 300 through a fifth air source pipe. One end of the third air source pipe is connected with a third air guide port of the electromagnetic valve 400, and the other end of the third air source pipe is connected with an air inlet of the mechanical control valve 500, so that compressed air conveyed by the electromagnetic valve 400 can reach the mechanical control valve 500. One end of the fourth air source pipe is connected with the fourth air guide port of the first quick-release valve 600, and the other end of the fourth air source pipe is connected with the air outlet of the machine control valve 500, so that the compressed air conveyed to the machine control valve 500 by the electromagnetic valve 400 can reach the first quick-release valve 600 through the fourth air source pipe. One end of the fifth air source pipe is connected with the fifth air guide port of the first quick exhaust valve 600, and the other end is connected with the air inlet of the air bag 300, so that the compressed air conveyed by the electromagnetic valve 400 can be conveyed into the air bag 300 through the fifth air source pipe after reaching the first quick exhaust valve 600. Meanwhile, when the solenoid valve 400 is powered on and the mechanical control valve 500 is closed, the compressed air is not continuously supplied to the air bag 300, and the compressed air supplied into the air bag 300 reaches the first quick-release valve 600 through the fifth air supply pipe and is discharged to the outside through the first quick-release valve 600.

In some embodiments of the present utility model, a sixth air guide port is further provided on the second quick-release valve 700, and the sixth air guide port is connected to a sixth air source pipe, and an end of the sixth air source pipe, which is far away from the sixth air guide port, is connected to a fourth air source pipe through a three-way connection assembly. One end of the sixth air source pipe is connected with a sixth air guide port of the second quick exhaust valve 700, and the other end of the sixth air source pipe is connected with the fourth air source pipe through a three-way connecting assembly. When the electromagnetic valve 400 is powered off and the mechanical control valve 500 is opened, compressed air conveyed by the electromagnetic valve 400 can be continuously conveyed through the fourth air source pipe after reaching the mechanical control valve 500, when the compressed air reaches the position of the three-way connecting assembly, part of the compressed air can be continuously conveyed to the first quick-release valve 600 along the fourth air source pipe, then conveyed to the inside of the air bag 300 through the fifth air source pipe, and the other part of the compressed air can enter the sixth air source pipe, is conveyed to the second quick-release valve 700 along the sixth air source pipe and is conveyed to the rotary cylinder 200 through the second air source pipe.

In some embodiments of the present utility model, a pressure switch 800 is also included. The connection port of the pressure switch 800 is connected with a seventh air source pipe, and one end of the seventh air source pipe far away from the connection port is connected with a fourth air source pipe through another three-way connecting component. One end of the seventh air source pipe is connected with the joint of the pressure switch 800, the other end of the seventh air source pipe is connected with the fourth air source pipe through another three-way connecting component, when compressed air reaches the position of the three-way connecting component, part of the compressed air is continuously conveyed to the first quick-release valve 600 along the fourth air source pipe and then conveyed to the air bag 300 through the fifth air source pipe, and the other part of the compressed air enters the seventh air source pipe to reach the pressure switch 800. The fourth air source pipe, the sixth air source pipe and the seventh air source pipe are communicated through the two three-way connecting assemblies, the pressure switch 800 can detect the pressure of the whole air source pipe, namely whether the air bag 300 is full or not can be judged according to the pressure detection result of the pressure switch 800, when the air bag 300 is full and seals the dome valve 100, the pressure switch 800 can send out a signal that the dome valve 100 is completely closed, and a worker can know the closing condition of the dome valve 100 in time conveniently. Meanwhile, the seventh air source pipe is connected with the fourth air source pipe through the three-way connecting assembly, so that the first quick exhaust valve 600 also isolates the pressure switch 800 from the air bag 300, and the situation that the air in the air bag 300 carries fine ash to enter the pressure switch 800 to cause signal false emission is avoided.

In some embodiments of the present utility model, the first quick drain valve 600 and the second quick drain valve 700 are both pneumatically controlled quick drain valves. When the solenoid valve 400 is powered, the compressed air in the rotary cylinder 200 may be discharged to the outside through the second quick discharge valve 700 from one side under the pneumatic control, and the compressed air in the air bag 300 may also be discharged to the outside through the first quick discharge valve 600. When the electromagnetic valve 400 is powered off, under the pneumatic control, compressed air can be conveyed into the rotary cylinder 200 through the second quick-release valve 700, and compressed air can also be conveyed into the air bag 300 through the first quick-release valve 600, so that the change of the flow direction of the compressed air is realized.

In some embodiments of the present utility model, the output end of the rotary cylinder 200 is provided with a rotary shaft 210, and an end of the rotary shaft 210 remote from the rotary cylinder 200 is connected to the dome valve 100. One end of the rotary shaft 210 is connected with the output end of the rotary cylinder 200, and the other end is connected with the dome valve 100, and under the action of the rotary cylinder 200, the rotary shaft 210 can axially rotate, so as to drive the dome valve 100 to rotate together, and realize opening and closing of the dome valve 100.

In some embodiments of the present utility model, the on-off switch 510 is disposed on the mechanically controlled valve 500, and the on-off switch 510 is a non-self-locking switch. The rotating shaft 210 is provided with a pressing rod 211, and one end of the pressing rod 211 far away from the rotating shaft 210 is opposite to the on-off switch 510.

Specifically, the on-off switch 510 is disposed on the machine control valve 500, and the on-off switch 510 is a non-self-locking switch. When the on-off switch 510 is pressed, the mechanical control valve 500 is opened, and the compressed air supplied from the solenoid valve 400 can reach the airbag 300 through the mechanical control valve 500. When the on-off switch 510 is released, the mechanical control valve 500 is automatically closed, and the compressed air supplied from the solenoid valve 400 to the airbag 300 is stopped. The pressing rod 211 is vertically fixed on the rotating shaft 210 and can rotate along with the axial rotation of the rotating shaft 210, and the pressing rod 211 has an L-shaped structure, and one end of the pressing rod 211 far away from the rotating shaft 210 is opposite to the on-off switch 510. When the electromagnetic valve 400 is powered on, the rotary shaft 210 drives the dome valve 100 to rotate clockwise under the action of the rotary cylinder 200, so as to complete the opening of the dome valve 100, and simultaneously, the compression bar 211 rotates clockwise along with the rotary shaft 210, so that one end of the compression bar 211 far away from the rotary shaft 210 is disconnected from the on-off switch 510, the mechanical control valve 500 is closed, and the electromagnetic valve 400 does not convey compressed air to the air bag 300. When the electromagnetic valve 400 is powered off, the rotary shaft 210 drives the dome valve 100 to rotate anticlockwise under the action of the rotary cylinder 200, so that the dome valve 100 is closed, and meanwhile, the compression bar 211 rotates anticlockwise along with the rotary shaft 210, so that one end of the compression bar 211 away from the rotary shaft 210 contacts the on-off switch 510 and presses the on-off switch 510, and then the mechanical control valve 500 is opened, and the electromagnetic valve 400 can also convey compressed air to the air bag 300. The operator is no longer required to independently control the mechanical control valve 500, and labor cost is saved.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "examples," "particular examples," "one particular embodiment," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The present utility model is not limited to the above preferred embodiments, and any person skilled in the art, within the scope of the present utility model, may apply to the present utility model, and equivalents and modifications thereof are intended to be included in the scope of the present utility model.

Claims

1. A blanking dome valve, comprising:

the dome valve can be arranged at a feed inlet of the ash bucket;

the rotary cylinder is connected with the dome valve and used for rotationally driving the dome valve to open and close;

the air bag is arranged below the dome valve and is used for sealing the dome valve;

the electromagnetic valve is communicated with one side of the rotary cylinder and is used for providing power for the rotary cylinder; the electromagnetic valve is also communicated with the air bag and is used for inflating the air bag;

the electromagnetic valve is communicated with the air bag through the mechanical control valve, and the mechanical control valve is used for enabling the electromagnetic valve to be communicated with or disconnected from the air bag;

a first quick-discharge valve is arranged between the mechanical control valve and the air bag and is used for discharging compressed air in the air bag.

2. The blanking dome valve of claim 1, wherein the blanking dome valve further comprises:

the second quick-release valve is communicated with one side of the rotary cylinder; the second quick-release valve is also communicated with the mechanical control valve.

3. The blanking dome valve of claim 2, wherein the solenoid valve is provided with a first air guide port connected to one side of the rotary cylinder through a first air source pipe;

the second quick exhaust valve is provided with a second air guide port, and the second air guide port is connected with the other side of the rotary cylinder through a second air source pipe.

4. The blanking dome valve of claim 3, wherein a third air guide port is further arranged on the electromagnetic valve, and the third air guide port is connected with an air inlet of the mechanical control valve through a third air source pipe;

the first quick exhaust valve is provided with a fourth air guide port and a fifth air guide port, the exhaust port of the mechanical control valve is connected with the fourth air guide port through a fourth air source pipe, and the fifth air guide port is connected with the air inlet of the air bag through a fifth air source pipe.

5. The blanking dome valve of claim 4, wherein a sixth air guide port is further provided on the second quick-release valve, the sixth air guide port is connected with a sixth air source pipe, and an end of the sixth air source pipe away from the sixth air guide port is connected with the fourth air source pipe through a three-way connecting assembly.

6. The blanking dome valve of claim 5, wherein the blanking dome valve further comprises:

the connecting port of the pressure switch is connected with a seventh air source pipe, and one end, far away from the connecting port, of the seventh air source pipe is connected with the fourth air source pipe through the other three-way connecting assembly.

7. The blanking dome valve of any of claims 2 to 6, wherein the first and second quick drain valves are both pneumatically controlled quick drain valves.

8. The blanking dome valve of claim 7, wherein the output end of the rotary cylinder is provided with a rotary shaft, and an end of the rotary shaft remote from the rotary cylinder is connected to the dome valve.

9. The blanking dome valve of claim 8, wherein the mechanically controlled valve is provided with an on-off switch, the on-off switch being a self-locking-free switch;

the rotary shaft is provided with a pressing rod, and one end of the pressing rod, which is far away from the rotary shaft, is opposite to the on-off switch.