KR101858203B1 - Fail-safe system for actuator - Google Patents

Abstract

The present invention relates to a valve opening and closing actuator with an emergency return means for a valve. In particular, in an actuator to operate a valve opening and closing a flow of fluid in an oil refining facility, a power plant, a reservoir, a pump station, a floodgate of a waterway, a dam, and the like, the valve is automatically returned to a closed state when power of an electric motor operating a driving shaft is cut off in an opened state of the valve, so as to prevent an accident likely to be caused by stop of the valve. According to the present invention, the actuator comprises: a tooth part formed on an outer circumferential surface of the driving shaft; a position installed to move forward and backward in a direction perpendicular to the driving shaft and including a rack gear part engaged with the tooth part; and an elastic body elastically supporting the piston in a forward direction in order to apply rotational pressure to the driving shaft in a closing direction.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an actuator for opening and closing a valve,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for opening and closing a valve having an emergency returning means for a valve, and more particularly to an actuator for actuating a valve for opening and closing a fluid flow in a refinery, a power plant, a reservoir, In order to prevent a safety accident that may occur due to the valve stop by automatically returning the valve to the closed state when the power of the electric motor for operating the drive shaft is shut off in the valve open state, A piston including a rack having a rack gear portion which is installed forward and backward in a direction orthogonal to the drive shaft and meshed with the toothed portion, and an elastic body which elastically supports the piston in a forward direction so as to receive a rotational pressure in the closing direction And an emergency return means for opening and closing the valve.

As a result of the reorganization of the increasing industrial structure, the integrated management system of the entire individual industry has been integrated into an unmanned integrated operating system, and an efficient integrated operating system has been constructed accordingly The automatic valve and various automatic flow control devices capable of efficiently controlling the flow of fluid remotely are rapidly spreading.

The electric actuator used in such an automatic flow control device is a driving device that is essential for automating a valve and a control damper, and is composed of a control part, an associated gear device, and a motor.

A typical structure of the electric actuator will be briefly described. A worm gear is provided at an end portion of a rotating shaft of a motor that rotates according to power application. The worm wheel is engaged with the worm gear and the reduction gears Various intermediate gears are installed and the valve is opened and closed as the drive shaft connected to the valve rotates in both directions by the rotational force transmitted through the intermediary gear to increase the torque.

However, in such a conventional electric actuator, when the power source for driving the motor is shut off due to a power failure or the like in an open state of the valve, the opening and closing operations of the valve become impossible due to the simultaneous stop of the driving means including the motor.

In this case, if the operation stoppage state of the valve is maintained for a long time, leakage of the fluid, equipment breakage, or the like may occur due to breakdown of the valve or fluid flowing through the valve during operation There is a risk of accident.

Therefore, most electric actuators have a manual handle that can manually open and close the valve so that the valve is operated manually in case of an emergency, so that safety accidents do not occur.

An actuator emergency driving device (hereinafter referred to as " Prior Art 1 ") of Korean Patent Laid-Open Publication No. 10-2008-0100887 (November 21, 2008)

The above-mentioned prior art 1 is an emergency driving device of an actuator which can operate a valve manually by actuating an actuator even during a power failure so as to quickly cope with an accident caused by gas or oil leakage.

In the conventional art 1, a third rotary shaft to which a rotary handle is fixed for manual operation of a plurality of rotary members, a rotary shaft, and a valve operated by interlocking of the gears, and a third rotary shaft to which the other gear and rotary shaft are integrally rotated And binding means.

Accordingly, in the prior art 1, when an emergency situation such as a power failure occurs and the actuator is not operated, the worker moves the third rotation shaft through which the rotation handle is fixed via the coupling means, another gear directly connected to the valve operation, The valve can be operated manually by rotating the rotary handle in the normal direction.

However, in the prior art 1, since the operator manually operates the valve manually, if a quick response is not made in the event of an emergency, there is a high risk of spreading due to a safety accident, and the operator can easily operate the valve according to the size of the valve, the structure of the actuator, The limit of the safety of the electric actuator is clear,

Therefore, there is a need for a safety device that automatically opens and closes the valve immediately after an emergency occurs even when the power is shut off.

As a conventional technique for solving the above problems, Korean Unexamined Patent Publication No. 10-2004-0018063 (Mar. 23, 2004) entitled " Emergency actuator for solenoid valve "

In the prior art 2, when the power of the power source unit is suddenly shut off, the rechargeable battery for activating the microcontroller that actuates the actuator immediately supplies the emergency power source to replace the emergency power source, To an actuator for a solenoid valve capable of preventing a loss in advance.

To this end, in the prior art 2, there is provided a power supply control method for a power supply system, which includes a full-open / full-closed state in which an emergency power supply is supplied when a power supply is shut down to open or close the valve body as a whole, The microcontroller can be preset in the memory of the microcontroller by using the fail mode switch so that the situation due to the malfunction of the power supply unit can be flexibly coped with. When the power supply unit is cut off and the power of the rechargeable battery is replaced, So that a signal of an emergency situation can be provided to the central control panel.

However, since the control of the valve is electrically performed using the rechargeable battery, the prior art 2 has a problem in that it can not be used in an emergency situation such as a power drop of the rechargeable battery due to long-term use or an electric defect in the actuator, There is a limit in that it can not function completely as the safety device of the actuator for the valve operation described above.

Accordingly, there is a need for a stabilizer that automatically opens or closes the valve regardless of any emergency situation through mechanical structure design.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a valve that automatically closes a valve when an emergency situation occurs, And an emergency return means of the valve opening / closing actuator,

The emergency return means is provided with a serrated portion provided on the outer circumferential surface of the drive shaft so that the drive shaft connected to the valve can be automatically returned to the closed state in the closed state by only the elastic force of the elastic body, A piston having a rack gear portion which is installed forward and backward in a direction orthogonal to the drive shaft and engaged with the toothed portion, and an elastic body which elastically supports the piston in a forward direction so as to receive a rotational pressure in the valve closing direction And an actuator for opening and closing.

In addition, the present invention is characterized in that the cylinder is arranged in an intersecting manner in a direction in which the cylinder portion is orthogonal to the drive shaft, so that the emergency return operation of the valve by the emergency return means can be performed more quickly and accurately, And an actuator for opening and closing the valve.

Further, the present invention is characterized in that the piston is connected to the body part connected to the elastic body and the body part connected to the elastic body so that the movement speed of the piston can be arbitrarily changed according to the type of the valve provided with the actuator, Wherein the housing and the cylinder portion are partitioned from each other by the body portion as a partition wall, wherein the body portion is provided with at least one member for communicating between the housing and the cylinder portion, There is provided an actuator for opening and closing a valve capable of changing a moving speed of a piston by adjusting the flow rate of air exhausted between the housing and the cylinder through adjustment of the opening range of the exhaust hole or opening and closing of the exhaust hole The purpose.

Further, the present invention is characterized in that, when the pistons crossed in the direction orthogonal to each other while minimizing the overall size of the actuator provided with the emergency return means, the rack gear portions of the other pistons orthogonal to the operating pieces And an actuator for opening and closing the valve.

According to an aspect of the present invention, there is provided an actuator for opening and closing a valve,

housing;

A drive shaft that is built in the housing and bi-directionally rotated by an electric motor to open and close the valve; And

And an emergency return means for automatically closing the valve by rotating the drive shaft in the other direction when the power is shut off in a state where the valve is opened by unidirectional rotation of the drive shaft,

Wherein the emergency return means comprises:

A tooth portion provided on an outer circumferential surface of the drive shaft;

A piston provided in the housing in a direction perpendicular to the drive shaft, the piston having a rack gear portion engaged with the toothed portion; And

And an elastic body elastically supporting the piston in a forward direction so that the driving shaft receives a rotational pressure in the other direction.

In the valve opening / closing actuator according to the present invention,

Wherein the housing includes a cylinder portion that is arranged in a direction orthogonal to the drive shaft,

And the piston is provided in each cylinder part so as to move back and forth.

In the valve opening / closing actuator according to the present invention,

Wherein the piston includes a body portion to which the elastic body is connected, and an actuating piece projecting forward from the body portion and having the rack gear portion,

Wherein the housing and the cylinder are partitioned from each other with the body portion being a partition wall,

The body portion may include at least one exhaust hole communicating between the housing and the cylinder portion to adjust the flow rate of air exhausted between the housing and the cylinder portion through the opening range adjustment of the exhaust hole or the opening / So that the moving speed of the piston can be changed.

Furthermore, in the valve opening / closing actuator according to the present invention,

And the operating piece is provided with a passage portion through which a rack gear portion of another piston orthogonal to the passage passes.

According to the present invention, there is provided an actuator for opening /

When the electric power supply to the electric motor for rotating the valve shaft is closed in a state where the valve is open, the electric motor is rotated so that the drive shaft is automatically returned to the closing direction through the piston which is actuated by the elastic force of the elastic body, It is possible to prevent the occurrence of various safety accidents due to the inability to control the valve even if a separate follow-up action is not immediately performed in an emergency such as a power failure,

The piston is provided in each of the cylinder portions arranged so as to be orthogonal to each other so that the emergency return operation of the valve by the emergency return means can be performed more quickly and accurately,

The operating speed of the piston can be arbitrarily changed according to the type of the valve provided with the actuator, the type of the fluid whose flow rate is controlled by the valve,

It is possible to prevent the collision of pistons operating in an intersecting direction while minimizing the overall size of the actuator to a minimum.

1 is a front cross-sectional view of an actuator for opening and closing a valve according to the present invention.
2 is a plan sectional view of an actuator for opening and closing a valve according to the present invention.
3 is a plan view and a side sectional view and a rear view of a piston according to the present invention.
4 is a front view and a side sectional view of a cylinder according to the present invention;
5 is an enlarged sectional view of the main part of Fig. 1;

While the present invention has been described in connection with certain embodiments, it is obvious that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In the drawings, the same reference numerals are used for the same reference numerals, and in particular, the numerals of the tens and the digits of the digits, the digits of the tens, the digits of the digits and the alphabets are the same, Members referred to by reference numerals can be identified as members corresponding to these standards.

In the drawings, the components are expressed by exaggeratingly larger (or thicker) or smaller (or thinner) in size or thickness in consideration of the convenience of understanding, etc. However, It should not be.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

 In the present application, the term " comprising " or " consisting of ", or the like, refers to the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

It is to be understood that the first to second aspects described in the present specification are merely referred to in order to distinguish between different components and are not limited to the order in which they are manufactured, It may not match.

In describing the actuator for opening and closing a valve according to the present invention, if an unstructured approximate direction reference is specified with reference to FIG. 1 for convenience, upper, lower, left, and right directions are determined as a direction in which gravity acts, Unless otherwise specified in the description and claims of the invention relating to this specification.

Hereinafter, an actuator for opening and closing a valve according to the present invention will be described with reference to the accompanying drawings.

1 and 2, which are a front sectional view and a plan sectional view of the present invention, the actuator for opening and closing a valve according to the present invention mainly comprises:

A housing (10);

A drive shaft 20 built in the housing 10 and bi-directionally rotated by the electric motor M to open and close a valve (not shown); And

And an emergency returning means (S) for automatically closing the valve by rotating the drive shaft (20) in the other direction when the valve is opened by unidirectional rotation of the drive shaft (20).

An electric motor M is installed on the upper portion of the housing 10 and is vertically installed so that the driving shaft 20 rotates in two directions through the housing 10.

The drive shaft 20 is connected to a rotary shaft M1 of the electric motor M by a reducer (not shown) including various shafts and / or gears and is rotated in both directions by an electric motor M, A valve mounting portion 21 is provided to open and close the valve.

Accordingly, when the drive shaft 20 is rotated in one direction by the electric motor M, the valve is opened. When the drive shaft 20 rotates in the other direction, the valve is closed to control the flow and flow rate of the fluid through the valve opening and closing .

The operation mechanism of the actuator for opening and closing the valve includes a switching lever, a clutch, a manual handle, and the like, which enable manual and automatic switching, and a detailed description of known configurations related thereto is omitted herein for the sake of convenience. do.

In addition, the housing 10 includes a cylinder portion 11 which is arranged in a direction orthogonal to the driving shaft 20,

And the emergency return means S is provided on each cylinder portion 11 such that the piston 30 moves back and forth.

That is, two or more cylinder portions 11 are perpendicularly intersected with each other in the horizontal direction perpendicular to the drive shaft 20.

Only two cylinder portions 11 may be arranged around the drive shaft 20 but four cylinder portions 11 are arranged around the drive shaft 20 in order to quickly and accurately rotate and return the drive shaft 20 It is preferable to arrange the piston 30 in each cylinder part 11 so as to be arranged in a cross shape in the housing 10 in a '+' shape.

3 to 5, the cylinder portion 11 is provided with a plurality of first receiving grooves 11a, and on the respective first receiving grooves 11a, an elastic body of the emergency returning means S (40).

At this time, the supporting block 12 is mounted in each first receiving groove 11a and the outer end of the elastic body 40 is supported on the first supporting end 12a of the supporting block 12. [

The support block 12 is provided with a screw hole (not shown) formed in the longitudinal direction of the elastic body 40. A guide bolt 13 having a head portion 13a is screwed to the screw hole , Restricting the advancing distance of the piston (30) and advancing and retreating.

Reference numeral 14 is a guide roller that guides the forward and backward movement of the piston 30 in contact with one surface of the operating piece 33 of the piston 30, particularly the opposite outer surface of the rack gear portion 33a.

The emergency returning means S of the valve according to the present invention may be additionally provided in a section where various shafts for rotating the drive shaft 20 are connected to each other. Depending on the type, The emergency returning means S of the valve according to the present invention may be applied to the drive shaft S for finalizing the opening and closing power of the valve to secure the installation stability of the emergency returning means S and the stability of the automatic returning of the valve, But it is not limited thereto.

That is, in the present invention, the drive shaft 20 may be a slave shaft directly connected to the valve or an intermediate shaft (not shown) connected to other reduction gears, or may be a slave shaft (not shown) May be implemented as a plurality of parts connected to each other so that the slave shaft or the intermediate shaft directly connected to the valve is essentially the same as the drive shaft 20 in that it ultimately transmits the rotational force of the electric motor M to the valve Or a similar concept equivalent thereto.

Specifically, as shown in Figs. 1 to 5, the emergency return means S includes:

A toothed portion 22 provided on the outer circumferential surface of the drive shaft 20;

A piston (30) having a rack gear portion (33a) installed forward and backward in a direction orthogonal to the drive shaft (20) in the housing (10) and meshing with the toothed portion (22); And

And an elastic body 40 elastically supporting the piston 30 in a forward direction so that the driving shaft 20 receives rotational pressure in the other direction.

The toothed portion 22 is a known gear having a concavo-convex structure formed in a part of the outer circumferential surface of the drive shaft 20. The toothed portion 22 is rotatably supported by the drive shaft 20, (20) rotates in both directions.

The piston 30 is moved back and forth along the rotation of the drive shaft 20 through the rack gear portion 33a engaged with the toothed portion 22. [

That is, when the drive shaft 20 rotates in one direction (valve opening direction) by the electric motor M, the rack gear portion 33a engaged with the toothed portion 22 receives the backward pressure and the piston 30 moves backward ,

Conversely, when the drive shaft 20 rotates in the other direction (valve closing direction) by the electric motor M, the rack gear portion 33a engaged with the toothed portion 22 receives the forward pressure and the piston 30 advances ,

This elasticity of the piston 30 causes the elastic body 40 to be compressed or expanded in the longitudinal direction.

The piston 30 includes a body portion 31 to which the elastic body 40 is connected and an operation piece 33 that is protruded forward from the body portion 31 and includes the rack gear portion 33a and,

The housing 10 and the cylinder 11 are partitioned from each other with the body 31 as a partition.

That is, the inner space of the housing 10, in which the drive shaft 20 is installed around the body 31, is isolated from the inner space of the cylinder 11 so that when the piston 30 moves back and forth, The air flow between the housing 10 and the cylinder portion 11 is blocked.

The body portion 31 is provided with a plurality of second receiving grooves 31a arranged at positions corresponding to the first receiving grooves 11a and the first and second receiving grooves 11a and 31a, The elastic body 40 is embedded.

At this time, the supporting member 32 is mounted on each first receiving groove 11a, and the inner end of the elastic member 40 is supported on the second supporting end 32a of the supporting member 32. [

Further, the support body 32 has a guide hole 32A through which the guide bolt 13 is inserted.

A locking end 32b protrudes from the inner circumferential surface of the outer end of the guide hole 32A so that when the support body 32 moves forward together with the piston 30 the head portion 13a is engaged with the locking end 32b And limits the advance distance of the piston (30).

Particularly, the body portion 31 is provided with at least one exhaust hole 31b for communicating the housing 10 with the cylinder portion 11 so that the opening range of the exhaust hole 31b or the exhaust hole 31b The moving speed of the piston 30 can be changed by controlling the flow rate of the air exhausted between the housing 10 and the cylinder portion 11 by adjusting the opening and closing of the piston 30.

That is, when the piston 30 is moved forward, the air inside the housing 10 flows into the cylinder portion 11 in a state where the air flow between the housing 10 and the cylinder portion 11 is restricted by the body portion 31 11)

By controlling the flow rate of the air through the exhaust hole 31b, the advance operation speed of the piston 30 can be changed and controlled separately from the elastic force of the elastic body 40 itself and the number of the elastic bodies 40 and the like.

For example, it is possible to adjust the flow rate of the exhausted air by narrowing or widening the opening degree of the exhaust hole 31b provided in the body portion 31, or by controlling the opening of the exhaust holes 31b provided in the body portion 31, The flow rate of the exhausted air can be adjusted by adjusting the number of the exhaust holes 31b,

The forward and backward moving speed of the body portion 31, i.e., the piston 30, varies depending on the flow rate of the air to be regulated.

In addition, the piston 30 is arranged in a '+' shape around the drive shaft 20, and a rack gear portion 33a is provided on an inner side surface of each of the operation pieces 33, and four pistons 30 Are engaged with the drive shaft 20 at the same time.

At this time, when the piston 30 is advanced, the rack gear portions 33a of the pistons 30 perpendicular to each other can collide with each other. The rack gear portion 33a of the other piston 30, which is perpendicular to the operating piece 33, And a passing portion 33b through which the portion 33a passes.

The piston 30 can move back and forth through the passage portion 33b by a distance (stroke) enough to rotate and return the drive shaft 20,

The passage portion 33b allows the pistons 30 to be mounted at the same height with respect to the drive shaft 20 regardless of the length of the actuating piece 33 so that the whole of the actuator The size can be minimized to a minimum.

Although only the "ㅁ" shaped passing portion 33b is shown in the drawings, the operating piece 33 may be formed in the shape of a letter "A" or "U" It is sufficient that the rack gear portion 33a of the rack gear 30 can be rotated back and forth.

Reference numeral 34 denotes a hermetic member provided on the outer peripheral surface of the body portion 31 to make the space between the housing 10 and the cylinder portion 11 airtight.

Next, the operation of the valve opening and closing actuator having the above-described configuration will be described.

When the operation of the electric motor M is controlled so as to open and close the valve in the state that the electric power is applied when the electric motor M is operated with the normal power supply, A rotational force is transmitted to the drive shaft 20 to normally open and close the valve,

At this time, the pistons 30 engaged with the drive shaft 20 are also advanced or retracted, and the elastic body 40 is compressed or expanded in the longitudinal direction.

When the supply of electric power to the electric motor M is cut off due to a power failure or the like, the operation of the electric motor M is stopped and the drive shaft 20 connected to the rotation shaft M1 The applied rotational force is lost.

The elastic force of the compressed elastic body 40 acts on the inner side of the housing 10 as the rotational force forcing the driving shaft 20 to rotate in the opening direction is lost in the state where the piston 30 is retracted,

The elastic force generated by the expansion of the elastic body 40 advances and presses the body portion 31 (more precisely, the support body 32) of the piston 30 so that the piston 30 advances, The toothed portion 22 is rotated by the driving shaft 33a so that the driving shaft 20 rotates in the closing direction of the valve so that the valve automatically closes and returns.

The output of the electric motor M or the torque of the reduction gear and the torque of the reduction gear of the elastic body 40 can be adjusted by controlling the flow rate of the air exhausted to the exhaust hole 31b of the body portion 31 while the piston 30 is moving back and forth. The moving speed of the piston 30, that is, the rotational speed of the drive shaft 20 can be changed independently of the elastic force,

When the piston 30 is advanced by the elastic force of the elastic body 40 and the valve is automatically returned to the closed state in the emergency state in which the power source is shut off, the moving speed of the piston 30 is adjusted to the exhaust hole 31b It is limited by the flow rate of the air passing therethrough so that the closing speed of the valve can be adjusted to suit the needs.

That is, if the opening range of the exhaust holes 31b (s) is widened or the number of the opened exhaust holes 31b is increased (in some cases, the exhaust holes 31b can be all opened) As the flow rate increases, the moving speed of the piston 30 increases accordingly,

Conversely, if the opening range of the exhaust holes 31b (s) is narrowed or the number of the opened exhaust holes 31b is reduced (in some cases, the exhaust holes 31b can be closed), the flow rate of the exhausted air The moving speed of the piston 30 is reduced correspondingly,

Accordingly, the closing speed of the valve can be changed by adjusting the moving speed of the piston 30 that rotates the driving shaft 20.

In addition, when the piston 30 is moved back and forth, the distance between the first and second receiving grooves 11a and 31a is increased while the support body 32 advances, so that the elastic body 40 is stably expanded.

At this time, the guide bolt 13 guides the forward and backward movement of the support 32 (i.e., the piston 30), and at the same time, the guide bolt 13 passes through the head portion 13a caught by the engagement end 32b of the support body 32, A forward pressure is applied to the piston 30 continuously even after the valve is closed, so that the rotational pressure is transmitted to the drive shaft 20 and the drive shaft 20 or the valve is damaged or damaged Can be prevented.

While the present invention has been described with reference to the accompanying drawings, it is to be understood that the present invention is not limited to the above-described embodiments, and various modifications, alterations, and changes may be made by those skilled in the art. And substitutions are to be construed as falling within the scope of protection of the present invention.

M: Electric motor M1:
S: Emergency return means
10: housing 11: cylinder part
11a: first receiving groove 12: support block
12a: first supporting end 13: guide bolt
13a: head portion 14: guide roller
20: drive shaft 21: valve mounting portion
22: serration part 30: piston
31: body portion 31a: second receiving groove
31b: exhaust hole 32: support
32A: Guide hole 32a: Second supporting end
32b: engaging end 33:
33a: rack gear portion 33b:
34: sealing member 40: elastic body

Claims (4)

housing;
A drive shaft that is built in the housing and bi-directionally rotated by an electric motor to open and close the valve; And
And an emergency return means for automatically closing the valve by rotating the drive shaft in the other direction when the power is shut off in a state where the valve is opened by unidirectional rotation of the drive shaft,

Wherein the emergency return means comprises:
A tooth portion provided on an outer circumferential surface of the drive shaft;
A piston provided in the housing in a direction perpendicular to the drive shaft, the piston having a rack gear portion engaged with the toothed portion; And
And an elastic body elastically supporting the piston in a forward direction so that the driving shaft receives a rotational pressure in the other direction,

Wherein the housing includes a cylinder portion that is arranged in a direction orthogonal to the drive shaft,
The piston is provided in each cylinder part so as to move back and forth,
Wherein the piston includes a body portion to which the elastic body is connected, and an actuating piece projecting forward from the body portion and having the rack gear portion,
Wherein the actuating piece is provided with a passage portion through which a rack gear portion of another piston orthogonal to the actuator is passed.
delete The method according to claim 1,
Wherein the housing and the cylinder are partitioned from each other with the body portion being a partition wall,
The body portion may include at least one exhaust hole communicating between the housing and the cylinder portion to adjust the flow rate of air exhausted between the housing and the cylinder portion through the opening range adjustment of the exhaust hole or the opening / And the moving speed of the piston can be changed.
delete

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