TW201804129A - Airtight piston device of gun body characterized by constituting a dry-type lubricative airtight assembly, so as to effectively prevent air leakage and structure abrasion caused by firing bullet - Google Patents

Abstract

An airtight piston device of gun body is provided. A first piston ring and a second piston ring are tightly assembled between a position limiting sleeve ring and a fastening sleeve member; one end of the fastening sleeve member is combined in a cylinder sleeve of a gun body; the first piston ring and the second piston ring mutally move in the radial direction; and the peripheral side is tightly and slidably connected to the inner wall of the cylinder sleeve to constitute a dry-type lubricative airtight assembly so as to effectively prevent air leakage and structure abrasion caused by firing bullet.

Description

Gun body airtight piston device

The invention relates to the technical field of toy gun structures, in particular to a gun body air-tight piston device of a gas firing structure inside a gas toy gun.

According to the general gas gun structure, a cylinder sleeve that guides a pressure gas (generally high-pressure ethylene butane or propane) is provided at a position corresponding to the rear end of the barrel. When the gas enters the cylinder liner, it can push the bullet (usually known as the plastic bullet of the BB bullet) to fire outward; and because the cylinder liner will move back and forth in the gun body during the firing to achieve automatic loading and recoil simulation, and A piston must be provided in the gun body corresponding to the opening at the rear end of the cylinder liner. According to the cylinder liner and the piston sleeve group, the airtight sliding group can be maintained to maintain the internal pressure during the forward and backward movement of the bullet. Therefore, generally, The pistons are made of rubber material structure with elastic deformation (such as rubber); while the pistons using rubber material have better air tightness due to their elastic deformation, but because of their large friction, they prevent the sliding with the cylinder liner. Therefore, a lubricating medium (generally silicone oil) must be used to improve the sliding flexibility of the cylinder liner.

However, because of the low-temperature relationship of the alkane-type pressure gas when firing the bullet, the entire gun will become colder and colder during firing. The associated will inhibit the deformation of the silicone piston and cause hardening, which will cause the existing gas to harden. The leak performance is caused by damage or reduction of airtightness, which in turn affects the firing of the bullet. It is for the use of the conventional rubber piston structure. One of the disadvantages.

Furthermore, because the alkane pressure gas used to fire the bullet will take away the silicone oil used in the piston during the firing operation, the friction between the piston and the inner wall of the cylinder liner will increase, which will affect the smoothness of the bullet firing operation. , And even cause wear of the piston structure, which is the second disadvantage of the use of the conventional colloidal piston structure.

In addition, if the silicone oil carried by the alkane pressurized gas adheres to the surface of the bullet during the firing process, it will affect the balance of the bullet after it is fired, causing the bullet to fly inaccurately. It is used for the conventional rubber piston structure Three disadvantages.

Finally, because the toy gun of alkane pressure gas is firing, the whole gun will become colder and colder. When the piston hardens and the friction with the inner wall of the cylinder liner becomes larger, the cylinder liner will be fired. In the future, it will not be able to return to its original position and cause gas leaks in the gas-tight parts to prevent normal use. This is the fourth disadvantage of the conventional rubber piston structure in use.

For example, the patent of the "Pneumatic Toy Pistol Gun Device" of the Republic of China Publication No. M518764, the structure of which is described in the abstract: a pneumatic toy pistol gun device, the gun device includes a slide seat and an air cylinder, inside The rear locking bridge locks a piston in front of its base, and the piston is assembled from the through hole at the rear end of the cylinder and is accommodated inside the cylinder, mainly with a second spring elastic axis between the cylinder and the interior of the piston. According to this, the second spring is connected between the inside of the cylinder and the piston, so as to achieve the progressive goals that the second spring is not easy to fall off, the service life is prolonged, and the cylinder and the piston are not easily dislocated when the cylinder and the piston are relatively displaced.

Although the above-mentioned patent is in the "embodiment" of the specification, The structure of the fifth to eighth figures is clearly stated. The second spring (reference numeral 26 in the figure) is changed to be arranged axially between the cylinder (reference numeral 2 in the figure) and the piston (reference numeral 4 in the figure) in the axial direction. Therefore, it can be excluded. The disadvantages of having to use a small wire diameter spring due to space constraints can be replaced by a thick wire spring with a strong elasticity. Therefore, the degree of simulation of the recoil force can be greatly improved, and the situation of falling off can be avoided. ． ． So that the cylinder (reference number 2 in the figure) can stably and elastically shift on the second track (reference number 32 in the figure) and is not easy to shift (see the fifth figure). ． ． Based on this, the goal of improving the existing defects is achieved.

However, because the above-mentioned patent does not improve the structure of the piston, even though the existing shortcomings of the structure of the gun are improved, the piston (number 4 in the figure) will still be affected by the pressure gas used in the alkane, and it cannot be avoided. Various disadvantages that may occur in the use of the piston structure.

In summary, at present, the gas-tight piston technology of the gas toy gun gun body is developed, and for the sake of convenience of material extraction, most of them still follow the rubber structure that is elastically deformed to achieve air-tightness, so that the use of the gun body still cannot avoid the following. Difficulties and disadvantages:

1. The low temperature of the gun body using alkane pressure gas will affect the airtight performance of the piston and cause air leakage, and the disadvantages of the firing operation of the bullet.

2. Because the alkane pressurized gas will release the piston's lubricating silicone oil and take away, the friction between the piston and the inner wall of the cylinder liner becomes larger, resulting in the disadvantage of structural wear.

3. The lubricating silicone oil released by the piston will adhere to the surface of the bullet and affect the balance of the travel after firing, resulting in the disadvantage of the bullet flying inaccurately.

4.Since the piston's lubricating silicone oil will be released and taken away by the alkane pressure gas, the friction between the piston and the inner wall of the cylinder liner becomes larger, causing the cylinder liner to fail to return to its original position. Stuck phenomenon, causing a large amount of air leakage in the airtight parts.

Therefore, how to deal with the air-tight pistons of the existing gas toy guns mentioned above will cause air leakage, and the structure will wear because the friction between the piston and the inner wall of the cylinder liner becomes larger, and the surface of the bullet will adhere to the lubricating silicone oil released by the piston. The inventors who innovated while flying were inaccurate, and the cylinder liner could not be returned to its original position, causing gas leaks in the air-tight parts of the air gun to be used normally. The inventors innovated these shortcomings, which are the difficulties to be solved in this case. .

A main object of the present invention is to provide a gun body air-tight piston device. A first piston ring and a second piston ring are tightly assembled between a limiting collar and a fixing kit, and are combined by one end of the fixing kit. Within a cylinder liner of a gun body, the first piston ring and the second piston ring are guided to each other through relative guide blocks and slide relative to each other radially, and the outer peripheral side is closely contacted with the sliding group on the inner wall of the cylinder liner and The air-tight combination of dry lubrication is formed to effectively avoid air leakage and structural wear caused by the bullet firing operation.

A secondary object of the present invention is to provide a gun body airtight piston device, which uses a dry lubrication combination of the first and second piston rings on the outer peripheral side and the inner wall of the cylinder liner to prevent the cylinder liner from being stuck and unable to return to its original position. As a result, the gas leaks in the airtight parts of the air gun and prevents it from being used normally, and avoids the shortcomings of bullets flying because of the adhesion of lubricating silicone oil to affect the balance.

In order to achieve the above-mentioned object and effect, the air-tight piston device of the gun body of the present invention includes: a limit collar; a first piston ring having a first guide groove sectioned in a radial direction; the first piston ring abuts against The limit collar; a second piston ring has a A second guide groove; a set of bolts is located between the first piston ring and the second piston ring, and the two ends of the bolt are respectively connected to the opposite ends of the first piston ring and the second piston ring; and a fixing kit, The outer diameter is smaller than the inner diameter of the first piston ring and the second piston ring. The fixing kit has a fixed end and a crimping portion extending radially at the opposite end. A plurality of air holes, the fixing kit is penetrated by a first piston ring and a second piston ring and is fixed in a cylinder sleeve of a gun body with a fixed end; the fixed end of the fixing kit is tightly connected to the limit sleeve; The joint portion and the first piston ring are in close contact with each other, and the second piston ring and the limit collar are in close contact with each other. The first piston ring and the second piston ring move radially with the pivoted assembly pin as a fulcrum. The outer circumferential side of the first piston ring and the second piston ring are in close contact with the sliding group on the inner wall of the cylinder liner.

A further technical feature of the present invention is that the first piston ring has a first outer flange protruding along the inner diameter toward the limit collar, and one end of the limit collar corresponding to the first piston ring is larger than the first protrusion. A limiting flange on the edge, and the first outer flange of the first piston ring moves between the inside of the limiting flange and the outer peripheral side of the fixing kit.

A further technical feature of the present invention is that the second piston ring has a second outer flange protruding along the inner diameter toward the crimping portion, and one end of the crimping portion corresponding to the second piston ring is larger than the second outer flange. A crimping flange, and the second outer flange of the second piston ring moves between the inside of the crimping flange and the outer peripheral side of the fixing kit.

A further technical feature of the present invention is that a further technical feature of the present invention is that the fixed end of the fixing kit has a small diameter hole and a small diameter flange protruding along the small diameter hole.

A further technical feature of the invention is that the first piston ring has a sleeve A first pivot hole is assembled in the set bolt, and the second piston ring has a second pivot hole sleeved in the set bolt.

A further technical feature of the present invention is that the plurality of air holes are introduced into the pressure gas in the cylinder liner of the gun body, forcing the first piston ring and the second piston ring to move radially with the pivoted assembly pin as a fulcrum, so that the first piston The outer peripheral sides of the ring and the second piston ring are airtight and slippery according to the diameter change of the inner wall of the cylinder liner.

A further technical feature of the present invention is that the first piston ring and the second piston ring are made of Teflon (also known as polytetrafluoroethylene).

(1) ‧‧‧Limit collar

(11) ‧‧‧Limit flange

(2) ‧‧‧First piston ring

(21) ‧‧‧First Pivot

(22) ‧‧‧First guide slot

(23) ‧‧‧First outer flange

(3) ‧‧‧Second Piston Ring

(31) ‧‧‧Second pivot hole

(32) ‧‧‧Second Guide Groove

(33) ‧‧‧Second Outer Flange

(4) ‧‧‧Fixing Kit

(41) ‧‧‧Crimping part

(411) ‧‧‧Stoma

(412) ‧‧‧Crimping flange

(42) ‧‧‧Fixed end

(421) ‧‧‧Small diameter hole

(422) ‧‧‧Small diameter flange

(5) ‧‧‧gun body

(51) ‧‧‧Cylinder liner

(511) ‧‧‧Guide

(512) ‧‧‧Cylinder liner inner wall diameter

(52) ‧‧‧ Bullets

(6) ‧‧‧set up

D‧‧‧size variable diameter

D1‧‧‧Cylinder liner small diameter inner wall

D2‧‧‧Cylinder liner large diameter inner wall

The first figure is a three-dimensional exploded view of the present invention.

The second figure is a schematic diagram of the three-dimensional combination of the present invention.

The third figure is a schematic sectional view of the combination of the present invention and the inner diameter of a cylinder liner.

The fourth figure is a schematic cross-sectional view of the embodiment of the present invention combined with the inner wall of a cylinder liner installed on a gun body.

The fifth figure is a partially enlarged sectional schematic view of the inner wall of a cylinder liner combined with a gun body of the present invention.

The sixth figure is a partially enlarged cross-sectional schematic diagram of the sliding displacement of the inner cylinder sleeve of the gun body installed during the firing operation.

The seventh figure is a schematic sectional view of the combination of the line VII-Ⅶ of the third figure according to the present invention.

The eighth figure is an air-tight combination diagram of the first piston ring and the second piston ring sliding relative to the inner wall diameter of a larger cylinder liner according to the present invention.

In order to achieve the above-mentioned objects and effects, as well as the technical means and The structure is described in detail with reference to the features and functions of the embodiment of the present invention in conjunction with the illustration.

Please refer to the first to fifth figures shown in the gun body airtight piston device of the present invention, which includes: a limit collar (1).

A first piston ring (2) has a first guide groove (22) sectioned in a radial direction, and the first piston ring (2) abuts against one end of the limit collar (1).

A second piston ring (3) has a second guide groove (32) sectioned in a radial direction.

A set of bolts (6) are located between the first piston ring (2) and the second piston ring (3), and the two ends of the bolts (6) are respectively pivoted to the first piston ring (2) and the second piston Opposite ends of the ring (3).

And a fixing kit (4) having an outer diameter smaller than the inner diameter of the first piston ring (2) and the second piston ring (3), the fixing kit (4) has a fixed end (42) and is located at the opposite end in a radial direction An extended crimping portion (41), and the crimping portion (41) is provided with a plurality of air holes (411), which are arranged around the periphery of the fixing kit (4), and the fixing kit (4) is provided with a first piston ring (2) And the second piston ring (3) are combined in a cylinder sleeve (51) of a gun body (5) with a fixed end (42), and the fixed end (42) of the fixing kit (4) is tightly connected to the limit collar (1), and the crimping part (41) of the fixing kit (4) and the first piston ring (2) are tightly connected, and the second piston ring (3) and the limit ring (1) are tightly connected to each other, The first piston ring (2) and the second piston ring (3) move radially with a pivoted set bolt (6) as a fulcrum, and the first piston ring (2) and the second piston ring (3) move radially. The outer peripheral side is closely connected to the inner wall of the cylinder liner (51).

The foregoing is the main technical features of the main embodiment of the present invention, which corresponds to the content of the first item of the scope of the patent application for this case, and the purpose and implementation mode of the present invention can be known in detail. First patent application The detailed content or additional technical features of the items are not intended to limit the scope of the first scope of the patent application. It should be understood that the first scope of the patent scope of this application does not necessarily include the technical features described in the scope of the remaining subsidiary patents.

The features of the components of the present invention are described in further detail below. In the first to fifth figures, the first piston ring (2) has a first convex protrusion protruding along the inner diameter toward the limit collar (1). Edge (23), one end of the limit collar (1) corresponding to the first piston ring (2) has a limit flange (11) larger than the first outer flange (23), and the first piston ring (2 The first outer flange (23) moves between the inside of the limiting flange (11) and the outer peripheral side of the fixing kit (4). Second, the second piston ring (3) has a second outer flange (33) protruding along the inner diameter toward the crimping portion (41). The crimping portion (41) corresponds to the second piston ring (3). One end has a crimping flange (412) larger than the second outer flange (33), and the second outer flange (33) of the second piston ring (3) is inside the crimping flange (412) and the fixing kit (4) Move between outer peripheral sides. Furthermore, the fixed end (42) of the fixing kit (4) has a small-diameter hole (421) and a small-diameter flange (422) protruding along the small-diameter hole (421). Moreover, the first piston ring (2) has a first pivot hole (21) sleeved on the set bolt (6), and the second piston ring (3) has a sleeved sleeve on the set pin (6). Second pivot hole (31). In addition, the plurality of air holes (411) introduce the pressure gas in the cylinder liner (51) of the gun body (5), forcing the first piston ring (2) and the second piston ring (3) to set a bolt (6) in a pivoted combination. ) Moves radially as a fulcrum, so that the outer peripheral sides of the first piston ring (2) and the second piston ring (3) are airtight and slippery according to the diameter change of the inner wall of the cylinder liner (51). Finally, the first piston ring (2) and the second piston ring (3) are made of Teflon.

As shown in the third figure, the present invention is arranged inside the inner diameter (512) of the cylinder liner of a gun body (5), and the first piston ring (2) and the second piston The rings (3) form a radial movement with each other by using the pivot pin set (6) as a fulcrum, so that the outer circumferential sides of the first piston ring (2) and the second piston ring (3) form a radial movement through relative radial movement. The size is variable in diameter D and is adapted to the change in the inner wall diameter (512) of the cylinder liner. Therefore, when the pressure gas in the cylinder liner (51) of the gun body (5) is introduced through the plurality of air holes (411) of the fixing kit (4), the first piston ring (2) inside the inner wall diameter (512) of the cylinder liner will be forced ) And the second piston ring (3) form a radial movement with each other by using a pivot pin set assembly pin (6) as a fulcrum.

As shown in Figures 5 and 6, according to the present invention, a first piston ring (2) and a second piston ring (3) are tightly arranged between a limiting collar (1) and a fixing kit (4). ), And one end of the fixing kit (4) is combined into a cylinder liner (51) of a gun body (5), and the first piston ring (2) and the second piston ring (3) pass through the opposite guide block provided Guide each other and slide relative to each other radially, and the outer peripheral side is in close contact with the inner wall of the cylinder liner (51) to form an air-tight combination of dry lubrication (without the use of lubricating oil); It is shown that when the user pulls the trigger of the gun body (5), the pressure gas will be guided into the interior through the guide hole (511) of the cylinder liner (51) in the direction of the hollow arrow, and the pressure gas will push a bullet in the direction of the solid arrow. (52) is fired outward, and when the cylinder liner (51) is displaced back and forth due to the change in internal pressure during the operation of firing the bullet (52), the first piston ring (2), a second piston ring (3 The airtight combination with the inner wall of the cylinder liner (51) ensures that no air leaks during firing operations, effectively improving the efficiency and smoothness of gun use. Moreover, as mentioned above, the characteristics of the first piston ring (2) and the second piston ring (3) made of Teflon (also known as polytetrafluoroethylene) further improve the avoidance of friction. The dry lubrication effect, and the structure is not affected by temperature deterioration and deformation, can avoid structural wear caused by friction in the firing operation of the bullet (52), and effectively improve the durability of the gun.

As mentioned above, the present invention further prevents the cylinder liner (51) from being stuck and unable to be returned by the dry lubrication combination of the outer peripheral side of the first piston ring (2) and the second piston ring (3) and the inner wall of the cylinder liner (51). The in-situ position caused a large amount of air leakage in the airtight parts and could not be used normally, which effectively improved the safety of gun use. Moreover, because the invention does not use lubricating oil, it can also prevent the bullet (52) from affecting the dynamic balance traveling in the air due to the adhesion of lubricating silicone oil, so that the bullet (52) fired by this creation can more accurately hit the targeted target.

As shown in Figures 3, 7, and 8, when the present invention introduces the pressure gas in the cylinder liner (51) from the plurality of air holes (411) of the fixing kit (4) in the arrow direction in the aforementioned firing operation, because The fixed end (42) of the fixing kit (4) is in close contact with the limit collar (1), and the crimping part (41), the first piston ring (2), and the second piston ring (3) of the fixing kit (4). And the restricting collar (1) are in close contact with each other, and the pressure gas is forced to push the first piston ring (2) and the second piston ring (3) outward in the direction of the arrows shown in Figs. The set of pivot joints (6) move radially as a fulcrum; accordingly, the diameter D of the outer peripheral side of the first piston ring (2) and the second piston ring (3) can be changed according to the cylinder liner. (51) The inner wall diameter changes (from the small-diameter inner wall D1 of the cylinder liner in the seventh figure to the large-diameter inner wall D2 of the cylinder liner in the eighth figure), and the air-tight slip group, and flexibly adapts to the inner wall diameter of the cylinder liner (512) (Such as a slight cone-shaped inner wall) can maintain airtightness without leaking air.

As described above, the present invention uses a first piston ring (2) and a second piston ring (3) which are not deteriorated and deformed by the temperature, and are closely connected to a limit collar (1) and a fixing kit (4). ), And one end of the fixing kit (4) is combined into a cylinder liner (51) of a gun body (5), and the first piston ring (2) and the second piston ring (3) pass through the pivoted group The bolt (6) is set as a fulcrum to move radially, and the outer peripheral side is in close contact with the sliding group on the inner wall of the cylinder liner (51) and constitutes a dry The air-tight combination of the lubricating type can definitely break through the current difficulties and shortcomings of the gas-tight piston technology of the gas toy gun body, and achieve the following advantages:

1. It can avoid air leakage caused by the firing of the bullet (52) and effectively improve the efficiency and smoothness of gun use.

2. It can avoid the structural wear caused by the friction during the firing operation of the bullet (52), and effectively improve the durability of the gun.

3. Avoid the cylinder liner (51) being stuck and unable to return to its original position, causing a large amount of air leakage in the airtight parts and preventing normal use, to achieve better use safety.

4. Avoid the bullet (52) because the adhesion of lubricating silicone oil affects the dynamic balance of traveling in the air, so that the bullet (52) fired by this creation can more accurately hit the targeted target.

5. The first piston ring (2) and the second piston ring (3) move radially through the pivoted assembly bolt (6) as a fulcrum, so that the outer peripheral side of the cylinder ring (51) changes with the inner wall of the cylinder liner (51). The tight-slip group can flexibly apply the slight change in the inner wall diameter of the cylinder liner (51) to maintain airtightness without leaking air.

The above is only used to explain the preferred embodiments of the present invention, and is not intended to limit the present invention in any form. Therefore, any modification related to the present invention made in the same spirit of creation Or the changes, which are other forms that can be implemented and have the same effect, should still be included in the scope of the present invention.

In summary, the "air-tight piston device of the gun body" of the present invention is indeed practical and cost-effective, which fully meets the needs of industrial development, and the disclosed structural creation also has an unprecedented innovative structure, so its "Novelty" should be considered, and the present invention can be compared The conventional structure is more effective and improved, so it is also "progressive". It fully complies with the requirements of the patent law on application requirements for invention patents in China. It has filed a patent application in accordance with the law, and invites the Bureau to review and affirm it.

(1) ‧‧‧Limit collar

(11) ‧‧‧Limit flange

(2) ‧‧‧First piston ring

(21) ‧‧‧First guide block

(22) ‧‧‧First guide slot

(23) ‧‧‧First outer flange

(3) ‧‧‧Second Piston Ring

(31) ‧‧‧Second pivot hole

(32) ‧‧‧Second Guide Groove

(33) ‧‧‧Second Outer Flange

(4) ‧‧‧Fixing Kit

(41) ‧‧‧Crimping part

(411) ‧‧‧Stoma

(412) ‧‧‧Crimping flange

(42) ‧‧‧Fixed end

(421) ‧‧‧Small diameter hole

(422) ‧‧‧Small diameter flange

(6) ‧‧‧set up

Claims (9)

An airtight piston device for a gun body includes: a limiting collar; a first piston ring having a first guide groove sectioned in a radial direction; the first piston ring abuts against the limiting collar; a second The piston ring has a second guide groove which is arranged in a radial direction; a set of bolts is located between the first piston ring and the second piston ring, and the two ends of the set bolt are pivotally connected to the first piston ring and the second piston, respectively. The opposite end of the ring; and a fixing kit having an outer diameter smaller than the inner diameter of the first and second piston rings, the fixing kit having a fixed end and a crimping portion extending radially at the opposite end, and crimping A plurality of air holes are arranged on the periphery of the fixing kit. The fixing kit is provided with a first piston ring and a second piston ring and is fixed in a cylinder sleeve of a gun body with a fixed end. The fixed end of the fixing kit is closely connected to Limit ring, while the crimping part of the fixing kit and the first piston ring are in close contact with each other, and the second piston ring and the limit ring are in close contact with each other, the first piston ring and the second piston ring are pivotally connected The set of bolts moves radially as a fulcrum, and the outer periphery of the first piston ring and the second piston ring Close contact with the inner wall of the cylinder liner slip group of. The airtight piston device for a gun body according to claim 1, wherein the first piston ring has a first outer flange protruding along the inner diameter toward the limit collar, and the limit collar corresponds to the first piston ring. One end has a limiting flange larger than the first outer flange, and the first outer flange of the first piston ring moves between the inside of the limiting flange and the outer peripheral side of the fixing kit. The gun body airtight piston device according to claim 1, wherein the second piston ring has a second outer flange protruding along the inner diameter toward the crimping portion, and the crimping portion has an end corresponding to the second piston ring. A crimping flange larger than the second outer flange, and the second outer flange of the second piston ring moves between the inside of the crimping flange and the outer peripheral side of the fixing kit. The gun body airtight piston device according to claim 2, wherein the second piston ring has a second outer flange protruding along the inner diameter toward the crimping portion, and the crimping portion has an end corresponding to the second piston ring. A crimping flange larger than the second outer flange, and the second outer flange of the second piston ring moves between the inside of the crimping flange and the outer peripheral side of the fixing kit. The gun body air-tight piston device according to claim 4, wherein the fixed end of the fixing kit has a small-diameter hole and a small-diameter flange protruding along the small-diameter hole. The airtight piston device for a gun body according to claim 1, wherein the first piston ring has a first pivot hole sleeved on the set bolt, and the second piston ring has a second sleeve holed on the set bolt Pivot hole. The gun body air-tight piston device according to any one of claims 1 to 6, wherein the plurality of air holes are introduced into the gas under pressure in the cylinder liner of the gun body, forcing the first piston ring and the second piston ring to pivotally The bolt is set as a fulcrum and moves radially, so that the outer circumferential side of the first piston ring and the second piston ring is air-tight and slippery according to the diameter change of the inner wall of the cylinder liner. The gun body airtight piston device according to any one of claims 1 to 6, wherein the first piston ring and the second piston ring are made of Teflon (also known as polytetrafluoroethylene). The gun body airtight piston device according to claim 7, wherein the first piston ring and the second piston ring are made of Teflon (also known as polytetrafluoroethylene).