A nail gun and its cylinder unit

Abstract

The present invention belongs to the technical field of fastening devices, and particularly relates to a nail gun and its cylinder unit. The nail gun includes a housing and a cylinder unit. The cylinder unit includes a cylinder body disposed in the housing, a piston movably disposed in the cylinder body, and a nail rod mounted on the piston. Among them, the cylinder body is made of plastic, and the tensile strength of the plastic is 50 MPa - 100 MPa. In this embodiment, the traditional metal cylinder body is changed into a plastic cylinder body, which greatly reduces the weight of the cylinder body, thereby reducing the weight of the entire gun, facilitating the reduction of the working intensity of the user, and also facilitating the lightweight development of the nail gun.

Description

Technical Field

[0001] The present invention belongs to the technical field of fastening devices, and particularly relates to a nail gun and its cylinder unit. Background Art

[0002] The invention patent with the application number 201310024663.2 discloses a compressed air nail gun, and the cylinder bodies of its cylinder unit are all made of metal. Although the rigidity and hardness of the metal are relatively good, its weight is relatively large. Since the user needs to hold the nail gun for a long time during use, if the weight of the nail gun is too heavy, it is easy to cause fatigue of the user's arm and affect the efficiency of the nail shooting operation. Summary of the Invention

[0003] To solve the above problems, a nail gun and its cylinder unit with low cost, high strength and light weight are provided.

[0004] The present invention adopts the following technical solutions:

[0005] A cylinder unit for a nail gun, which is installed in the housing of the nail gun and is used to provide the power to strike the nail under the action of high-pressure gas, includes: a cylinder body disposed in the housing; a piston movably disposed in the cylinder body, dividing the inner cavity of the cylinder body into an air inlet cavity and an air outlet cavity; and a nail shooting rod installed on the piston for striking the nail; wherein, the cylinder body is made of plastic, and the tensile strength of the plastic is 50 MPa - 100 MPa.

[0006] The cylinder unit for a nail gun provided by the present invention may further have the following characteristics. It further includes an annular buffer member. Wherein, the cylinder body has an air outlet side end disposed on the air outlet cavity side, and the air outlet side end has an annular surface that fits with the housing as the first fitting surface. The annular buffer member is installed around the nail shooting rod on the air outlet side end and has an annular surface that fits with the air outlet side end as the second fitting surface. The length of the second fitting surface in the axial direction of the cylinder body is at least half of the length of the first fitting surface in the axial direction.

[0007] The cylinder unit for a nail gun provided by the present invention may further have the following characteristics. It further includes: a spacer sleeve hermetically sleeved on the cylinder body and hermetically combined with the housing; and an annular one-way air flow control member surrounding the cylinder body; wherein, the spacer sleeve, the cylinder body and the housing form a return air chamber near the air outlet side end. The cylinder body further has a plurality of first channels disposed near the air outlet side end and a plurality of second channels disposed near the spacer sleeve. The first channels are used to connect the air outlet cavity and the return air chamber, and the second channels are used to connect the air inlet cavity and the return air chamber; the annular one-way air flow control member covers all the second channels and is used to prevent the air flow in the return air chamber from flowing to the air inlet cavity.

[0008] The cylinder unit for a nail gun provided by the present invention may further have the following characteristics: The annular buffer member further has a first conical surface and a second conical surface respectively connected to both sides of the first fitting surface. The first conical surface faces the air outlet cavity, the second conical surface faces away from the air outlet cavity, and the first channel is provided at a position where the first conical surface faces the side wall of the cylinder block.

[0009] The cylinder unit for a nail gun provided by the present invention may further have the following characteristics: The cylinder block has a plurality of first reinforcing ribs surrounding the outer wall of the cylinder block and a plurality of second reinforcing ribs parallel to the axis of the cylinder block. The first reinforcing ribs are annular or spiral, and the second reinforcing ribs intersect with the first reinforcing ribs.

[0010] The cylinder unit for a nail gun provided by the present invention may further have the following characteristics: It further includes a sizing ring. The cylinder block further has an intake side end provided on the intake cavity side. The sizing ring is made of metal and is sleeved on the intake side end.

[0011] The cylinder unit for a nail gun provided by the present invention may further have the following characteristics: It further includes an end sealing fitting ring, which is provided between the intake side end and the sizing ring and is fitted with the intake side end for sealing connection with an external member provided on the intake side end.

[0012] A nail gun includes: a housing; and a cylinder unit installed in the housing for providing the power to strike a nail under the action of high-pressure gas. The cylinder unit is the above-mentioned cylinder unit for a nail gun.

[0013] The nail gun provided by the present invention may further have the following characteristics: It further includes a control valve unit, which is provided as an external member of the cylinder unit on the intake side end of the cylinder unit.

[0014] The functions and effects of the present invention:

[0015] The present invention changes the traditional metal cylinder block into a plastic cylinder block, greatly reducing the weight of the cylinder block, thereby reducing the weight of the whole gun, which is beneficial to reducing the working intensity of the user and also beneficial to the lightweight development of the nail gun.

[0016] The length of the second fitting surface of the present invention in the axial direction of the cylinder block is at least half of the length of the first fitting surface in the axial direction. When the piston strikes the annular buffer member, the impact force received by the annular buffer member can be quickly transmitted to the metal housing through the cylinder block to reduce the impact on the plastic cylinder block. At this time, the more the first fitting surface and the second fitting surface coincide in the radial projection length direction of the cylinder block, the higher the impact force transmission efficiency, the lower the damage degree of the plastic cylinder block, and the longer the service life.

[0017] A shaping ring made of metal material is installed at the intake side end of the cylinder block. When high-pressure gas enters, it ensures that the cylinder block has sufficient strength to support it and prevents the intake side end from deforming or even bursting.

[0018] In addition, a first reinforcing rib and a second reinforcing rib are also provided on the outer wall of the cylinder block to further ensure the strength of the cylinder block under the condition of a certain thickness. Brief Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the nail gun of the present invention;

[0020] Figure 2 is an exploded view of the power driving device of the present invention;

[0021] Figure 3 is a sectional view of the power driving device of the present invention;

[0022] Figure 4 is a schematic structural diagram of the cylinder unit of the present invention;

[0023] Figure 5 is a sectional view of the cylinder unit of the present invention;

[0024] Figure 6 is Figure 3 a partial enlarged view of part A in

[0025] Figure 7 the working principle diagram of the power driving device of the present invention.

[0026] The meanings represented by the reference numerals in the drawings:

[0027] 100 - Nail feeding device; 200 - Nozzle; 300 - Power driving device;

[0028] 301 - Outer shell; 302 - Cylinder unit; 303 - Control valve unit; 304 - Control unit;

[0029] 311 - Intake cavity; 312 - Exhaust cavity; 313 - Rear cover; 314 - Intake passage; 315 - Air storage chamber; 316 - Return air chamber; 317 - Control chamber; 318 - Handle;

[0030] 321 - Cylinder block; 3210 - Outlet side end; 3211 - First fitting surface; 3212 - Second fitting surface; 3213 - Clamping groove; 3214 - First duct; 3215 - Second duct; 3216 - Inlet side end; 322 - Piston; 3221 - Piston seal ring; 323 - Nail shooting rod; 324 - Annular buffer member; 3241 - Mounting hole; 3242 - First conical surface; 243 - Second conical surface; 325 - Shaping ring; 326 - End sealing and fitting ring; 3261 - Sealing end face; 3262 - Clamping ring; 327 - Spacer sleeve; 3271 - First spacer sleeve seal ring; 3272 - Second spacer sleeve seal ring; 328 - Annular one - way air flow control member; 329 - First reinforcing rib; 330 - Second reinforcing rib;

[0031] 341 - Nail shooting switch; 342 - Air valve. Detailed implementation mode

[0032] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be specifically described below in conjunction with embodiments and drawings.

[0033] Figure 1 It is a schematic structural diagram of the nail gun of the present invention.

[0034] As Figure 1 shown, the nail gun includes a gun nozzle 200, a nail feeding device 100 and a power driving device 300.

[0035] The gun nozzle 200 is provided with a firing channel and has a nail shooting outlet for nails; the nail feeding device has a nail passing channel, and a row of nails is installed in the nail passing channel, and the firing channel communicates with the nail passing channel. The rear end of the gun nozzle 200 is provided with a power device 300, and the power driving device 300 is used to provide firing power for the nails of the row of nails.

[0036] Figure 2 It is an exploded view of the power driving device of the present invention, Figure 3 It is a sectional view of the power driving device of the present invention.

[0037] As Figure 2-3 shown, the power driving device 300 includes a housing 301, a cylinder unit 302, a control valve unit 303 and a control unit 304.

[0038] The housing 301 is a metal housing, and a handle 318 is extended and provided at its bottom. The handle 318 has an air inlet channel 314 for connecting to a high - pressure air source. The rear end of the housing 301 is installed with a rear cover 313, which is convenient for the installation of internal structures such as the cylinder unit 302 and the control valve unit 303.

[0039] The cylinder unit 302 is installed inside the housing 301. Inside the cylinder unit 302, there is an air inlet chamber 311 and an air outlet chamber 312. Outside, a gas storage chamber 315 that forms a connected intake passage 314 with the housing 301 through a spacer sleeve 327 and a return air chamber 316 that communicates with the air outlet chamber 312 are provided. The air inlet chamber 311 can communicate with the gas storage chamber 315, and the air outlet chamber 312 communicates with the atmosphere.

[0040] The control valve unit 303 is movably installed in the rear cover 313 at the rear end of the housing 301, and forms a control chamber 317 that can communicate with the outside and the gas storage chamber 315 with the rear cover 313.

[0041] The control valve unit 303 is movably and sealably connected to the cylinder unit 302, and forms a separation surface for high-pressure gas to enter the air inlet chamber 311 therewith. The control unit 304 is used to respectively control the sealing and conduction between the gas storage chamber 315 and the control chamber 317, and between the control chamber 317 and the outside.

[0042] The control unit 304 includes a nail shooting switch 341 installed at the upper end of the handle 318 and a pneumatic valve 342. The nail shooting switch 341 is used to control the operation of the pneumatic valve 342, and the pneumatic valve 342 is used to control the sealing and conduction between the control chamber 317 and the outside.

[0043] Among them, the specific structure of the cylinder unit 302 is as follows:

[0044] Figure 4 is a schematic structural diagram of the cylinder unit of the present invention, Figure 5 is a cross-sectional view of the cylinder unit of the present invention.

[0045] As Figure 4-5 shown, the cylinder unit 302 includes a cylinder block 321, a piston 322, a nail shooting rod 323, an annular buffer member 324, a shaping ring 325, an end sealing fitting ring 326, a spacer sleeve 327, and an annular one-way air flow control member 328.

[0046] The cylinder block 321 is installed in the housing 301 of the nail gun. The cylinder block 321 is made of plastic, and the tensile strength of the plastic is 50 MPa - 100 Mpa, preferably engineering plastic.

[0047] The piston 322 is movably installed in the inner cavity of the cylinder block 321, and divides the inner cavity of the cylinder block 321 into an air inlet chamber 311 and an air outlet chamber 312. An outer ring of the piston 322 is provided with a piston sealing ring 3221 that contacts the cylinder block 321, for better sealing of the air inlet chamber 311 and the air outlet chamber 312.

[0048] Since the cylinder block 321 is made of plastic, the friction coefficient between the piston 322 and the cylinder block 321 is relatively small, and due to the characteristics of the engineering plastic itself, a self-lubricating effect can also be generated, which is beneficial to the movement of the piston 322.

[0049] The nail shooting rod 323 is fixed at the center of the piston 322 and is used to strike the nail.

[0050] An installation hole 3241 for the nail shooting rod 323 to pass through is provided in the middle of the annular buffer member 324, and the air outlet cavity 312 communicates with the atmosphere through the installation hole 3241 for exhausting air.

[0051] Compared with the original metal cylinder block, the plastic cylinder block of this embodiment greatly reduces the weight of the cylinder block and the production cost, laying a solid foundation for the lightweight development of the product.

[0052] In order to meet the requirements of a high-power nail gun, when the strength of the material itself is certain, it is also necessary to further improve the strength of the plastic cylinder block. Therefore, structural improvements are mainly made to the positions of the air outlet side end 3210 and the air inlet side end 3216 of the cylinder block 321.

[0053] Figure 6 is Figure 3 The partial enlarged view at position A in.

[0054] As Figure 6 shown, the cylinder block 321 has an air outlet side end 3210 provided on the air outlet cavity side, and the air outlet side end 3210 has an annular surface that fits with the outer shell 301 as the first fitting surface 3211; the annular buffer member 324 surrounds the nail shooting rod installation 323 at the air outlet side end 3210 and has an annular surface that fits with the air outlet side end 3210 as the second fitting surface 3212. The length of the second fitting surface 3212 in the axial direction of the cylinder block 321 is at least half of the length of the first fitting surface 3211 in the axial direction.

[0055] When the piston 322 strikes the annular buffer member 324, the impact force received by the annular buffer member 324 can be quickly transmitted to the metal outer shell 301 through the cylinder block 321 to reduce the impact on the plastic cylinder block 321. At this time, the more the first fitting surface 3211 and the second fitting surface 3212 coincide in the radial projection of the cylinder block 321, the higher the efficiency of the impact force transmission, the lower the damage degree of the plastic cylinder block, and the longer the service life.

[0056] As Figure 5 shown, the cylinder block 321 has an air inlet side end 3216 provided on the air inlet cavity side.

[0057] The end sealing fitting ring 326 is fitted in the air inlet side end 3216 of the cylinder block 321 for sealing connection with an external member provided on the air inlet side end. In this embodiment, the external member is a control valve unit.

[0058] Specifically, the end sealing and fitting ring 326 has a sealing end face 3261 for abutting against the control valve unit 303 and a clamping ring 3262 for fixing itself. The sealing end face 3261 covers the intake side end 3216 of the cylinder block 321, and a clamping groove 3213 is also provided on the outside of the intake side end 3216. The end sealing and fitting ring 326 is fitted into the clamping groove 3213 through the clamping ring 3262.

[0059] The sizing ring 325 is a circular ring made of metal, which is sleeved on the intake side end 3216. In this embodiment, the sizing ring 325 is installed outside the end sealing and fitting ring 326.

[0060] When high-pressure gas enters the cylinder block 321 instantaneously, the intake side end 3216 of the cylinder block 321 will expand and deform under the pressure of the high-pressure gas. At this time, the sizing ring 325 can reinforce the intake side end 3216 of the cylinder block 321 to prevent it from bursting. At the same time, since a soft end sealing and fitting ring 326 is provided between the sizing ring 325 and the cylinder block 321, it can protect the intake side end 3216 and further prevent the intake side end 3216 from deforming or even bursting.

[0061] A spacer sleeve 327 is hermetically sleeved on the outside of the middle part of the cylinder block 321, and the spacer sleeve 327 is hermetically combined with the housing 301. When high-pressure gas enters the cylinder unit, the spacer sleeve 327 can support and shape the middle part of the cylinder block 321 to prevent the middle part of the cylinder block from deforming or even bursting.

[0062] Specifically, the spacer sleeve 327 is in a circular ring shape. A first spacer sleeve sealing ring 3271 is installed between the inner ring of the spacer sleeve 327 and the cylinder block 321, and a second spacer sleeve sealing ring 3272 is installed between the outer ring of the spacer sleeve 327 and the housing 301. The first spacer sleeve sealing ring 3271 and the second spacer sleeve sealing ring 3272 are used for sealing and preventing gas leakage.

[0063] The spacer sleeve 327, the cylinder block 321 and the housing 301 form a gas return chamber 316 near the outlet side end 3210.

[0064] The cylinder block 321 also has a plurality of first channels 3214 provided near the outlet side end 3210 and a plurality of second channels 3215 provided near the spacer sleeve 327. The first channels 3214 are used to connect the outlet chamber 312 and the gas return chamber 316. In this embodiment, 6 first channels 3214 are provided, all of which are in a long strip shape.

[0065] The second channels 3215 are used to connect the intake chamber 317 and the gas return chamber 316. The second channels 3215 in this embodiment are circular through holes and are circumferentially distributed on the cylinder block 321.

[0066] The annular unidirectional air flow control member 328 covers all the second channels 3215 to prevent the air flow in the air return chamber 316 from flowing into the intake chamber 317. Specifically, the annular unidirectional air flow control member 328 is an annular diaphragm installed on the outside of the cylinder block 321 where the second channels 3215 are located. When high-pressure gas enters the low-pressure air return chamber 316 from the high-pressure intake chamber 317, the annular diaphragm expands and the second channels 3215 open; conversely, when high-pressure gas enters the low-pressure intake chamber 317 from the high-pressure air return chamber 316, the annular diaphragm does not change its shape and always seals the second channels 3215, playing a role of unidirectional conduction. Its ultimate purpose is to allow the high-pressure gas in the air return chamber 316 to enter the air outlet chamber 312, thereby pushing the piston 322 to reset.

[0067] The annular buffer member 324 is preferably a rubber buffer member, which has a first conical surface 3242 and a second conical surface 3243 respectively connected to both sides of the first fitting surface 3211. The first conical surface 3242 faces the air outlet chamber, and the second conical surface 3243 faces away from the air outlet chamber.

[0068] The first channel 3214 is arranged at a position where the first conical surface 3242 faces the side wall of the cylinder block 321. Specifically, the first channel 3214 is located in the triangular annular space formed by the first conical surface 3242 and the side wall of the cylinder block 321. At this time, it can prevent the first channel 3214 from being blocked by the piston 322, which is beneficial for the high-pressure gas in the air return chamber 316 to enter the air outlet chamber 312, thereby pushing the piston 322 to reset.

[0069] As Figure 4 shown, in order to further increase the strength of the plastic cylinder block 321, the cylinder block 321 has a plurality of first reinforcing ribs 329 surrounding the outer wall of the cylinder block 321 and a plurality of second reinforcing ribs 330 parallel to the axis of the cylinder block 321. The first reinforcing ribs 329 are annular or spiral, and the second reinforcing ribs 330 intersect with the first reinforcing ribs 329.

[0070] Among them, in order to facilitate the installation of the spacer 327, the outer diameter of the first reinforcing rib 329 near the air outlet side end 3210 of the cylinder block 321 is smaller than the outer diameter of the first reinforcing rib 329 near the air intake side end 3216 of the cylinder block 321.

[0071] The specific operation process of the nail gun in this embodiment for shooting nails is as follows:

[0072] Before shooting a nail, as Figure 3 shown, the control chamber 317 and the air storage chamber 315 are both connected to the intake passage 314 and filled with high-pressure gas at equal pressure; the piston 322 and the nail shooting rod 323 are located at the end of the cylinder block 321 close to the control valve unit 303.

[0073] Figure 7 The working principle diagram of the power driving device of the present invention.

[0074] When firing a nail, as Figure 7 shown, the user pulls the nail firing switch 341 to open the air valve 342, connecting the control chamber 317 to the outside; at the same time, the intake end of the intake passage 314 and the connecting part between the control chamber 317 and the intake passage 314 are closed. At this time, the air pressure in the air storage chamber 315 is higher than that in the control chamber 317, causing the control valve unit 303 to move backward and open the separation surface; the high-pressure gas in the air storage chamber 315 instantly becomes an air bullet (the flow direction of this high-pressure gas refers to the solid-line arrow in Figure 7 ), pushing the piston 322 of the cylinder unit 302 and the nail rod 323 to move at high speed in the direction close to the annular buffer member 324, and hitting the nail in the nozzle 200 to achieve nail firing.

[0075] When the piston 322 moves between the second orifice 3215 and the first air island 3214, the high-pressure gas will enter the air return chamber 316 from the intake chamber 311 through the second orifice 3215 and the annular one-way air flow control member 328, and the air return chamber 316 temporarily stores a part of the high-pressure gas. After the piston 322 hits the annular buffer member 324, a part of the high-pressure gas in the air return chamber 316 (the flow direction of this high-pressure gas refers to the dashed-line arrow in Figure 7 ) will enter the air outlet chamber 312 through the first orifice 3214 and push the piston 322 to reset, thus preparing for the next nail firing.

[0076] <Function and Effect of the Embodiment>

[0077] This embodiment provides a cylinder unit and a nail gun including the cylinder unit. The nail gun also has a housing. The cylinder unit includes a cylinder body disposed in the housing, a piston movably disposed in the cylinder body, and a nail rod mounted on the piston. Among them, the cylinder body is made of plastic, and the tensile strength of this plastic is 50 MPa - 100 MPa. This embodiment changes the traditional metal cylinder body into a plastic cylinder body, greatly reducing the weight of the cylinder body, thereby reducing the weight of the whole gun, which is beneficial to reducing the working intensity of the user and also beneficial to the lightweight development of the nail gun.

[0078] In addition, since the cylinder body in this embodiment is made of engineering plastic, the friction coefficient between the piston and the cylinder body is small. The piston is provided with a piston sealing ring for sealing with the inner wall of the cylinder body. Due to the characteristics of the engineering plastic itself, it can produce a self-lubricating effect, which is beneficial to the smooth movement of the piston in the cylinder body while ensuring sealing.

[0079] In addition, the cylinder unit further includes an annular buffer member. The cylinder block has an air outlet side end disposed on the air outlet cavity side. The air outlet side end has an annular surface that fits against the outer shell as a first fitting surface. The annular buffer member is mounted around the nail shooting rod at the air outlet side end and has an annular surface that fits against the air outlet side end as a second fitting surface. The length of the second fitting surface in the axial direction of the cylinder block is at least half of the length of the first fitting surface in the axial direction. When the piston impacts the annular buffer member, the impact force received by the annular buffer member can be quickly transmitted to the metal outer shell through the cylinder block to reduce the impact on the plastic cylinder block. At this time, the more the first fitting surface and the second fitting surface coincide in the radial projection length direction of the cylinder block, the higher the efficiency of impact force transmission, the lower the damage degree of the plastic cylinder block, and the longer the service life.

[0080] In addition, the cylinder unit further includes a spacer sleeve and an annular unidirectional air flow control member. The spacer sleeve is hermetically sleeved on the cylinder block and is hermetically combined with the outer shell, so that a return air chamber is formed by the spacer sleeve, the cylinder block and the outer shell near the air outlet side end. The cylinder block also has a plurality of first channels disposed near the air outlet side end and a plurality of second channels disposed near the spacer sleeve. The first channels are used to connect the air outlet cavity and the return air chamber, and the second channels are used to connect the air inlet cavity and the return air chamber; the annular unidirectional air flow control member covers all the second channels and is used to prevent the air flow in the return air chamber from flowing into the air inlet cavity. When shooting a nail, high-pressure gas will enter the return air chamber through the second channels. After the nail shooting is completed, the high-pressure gas in the return air chamber will enter the air outlet cavity through the first channels, thereby pushing the piston to reset and preparing for the next nail shooting.

[0081] In addition, the annular buffer member further has a first conical surface and a second conical surface respectively connected to both sides of the first fitting surface. The first conical surface faces the air outlet cavity, and the second conical surface faces away from the air outlet cavity. The first channels are disposed at positions where the first conical surface faces the side wall of the cylinder block. This can prevent the first channels from being blocked by the piston, which is beneficial to the high-pressure gas in the return air chamber entering the air outlet cavity, thereby pushing the piston to reset.

[0082] In addition, the cylinder block has a plurality of first reinforcing ribs surrounding the outer wall of the cylinder block and a plurality of second reinforcing ribs parallel to the axis of the cylinder block. The first reinforcing ribs are annular or spiral, and the second reinforcing ribs intersect with the first reinforcing ribs, thereby further improving the strength of the plastic cylinder block.

[0083] In addition, the cylinder unit further includes a sizing ring. The cylinder block also has an air inlet side end disposed on the air inlet cavity side. The sizing ring is made of metal and is sleeved on the air inlet side end. When high-pressure gas enters the cylinder block instantaneously, the air inlet side end of the cylinder block will expand. At this time, the sizing ring can reinforce the air inlet side end of the cylinder block to prevent it from cracking.

[0084] In addition, the cylinder unit further includes an end sealing fitting ring, which is arranged between the intake side end and the sizing ring and is fitted with the intake side end for sealing connection with an external component arranged on the intake side end. The external component is a control valve unit. The structure of the end sealing fitting ring facilitates installation and is conducive to increasing the sealing performance with the control valve unit.

[0085] The above embodiments are only used to illustrate the specific implementation manners of the present invention, but the present invention is not limited to the scope described in the above embodiments. Various deformations or modifications that can be made by those of ordinary skill in the art without creative labor within the scope of the appended claims still fall within the protection scope of this patent.

Claims

1. A cylinder unit for a nail gun, installed inside the housing of the nail gun, and used to provide the power to strike a nail under the action of high-pressure gas, characterized in that, Comprising: A cylinder block, disposed within a housing; A piston, movably disposed within the cylinder block, dividing the inner cavity of the cylinder block into an intake chamber and an exhaust chamber; A nail driving rod, mounted on the piston for striking the nail; An annular buffer member; A sizing ring, made of metal; and An end sealing and fitting ring, wherein the cylinder block is made of an engineering plastic with a tensile strength of 50MPa - 100Mpa, the cylinder block has an exhaust side end disposed on the exhaust chamber side and an intake side end disposed on the intake chamber side, the exhaust side end has an annular surface in contact with the housing as a first contact surface, the annular buffer member is mounted around the nail driving rod at the exhaust side end and has an annular surface in contact with the exhaust side end as a second contact surface, the length of the second contact surface in the axial direction of the cylinder block is at least half of the length of the first contact surface in the axial direction, the sizing ring is sleeved on the intake side end, the end sealing and fitting ring is disposed between the intake side end and the sizing ring and is fitted with the intake side end for sealing connection with a control valve unit disposed on the intake side end, the end sealing and fitting ring has a sealing end face for abutting against the control valve unit and a clamping ring for fixing itself, the sealing end face covers the intake side end of the cylinder block, and a clamping groove is further formed on the outer side of the intake side end. The end sealing and fitting ring is fitted in the clamping groove through the clamping ring.

2. The cylinder unit for a nail gun according to claim 1, characterized in that, Further comprising: A spacer sleeve, sealingly sleeved on the cylinder block and sealingly combined with the housing; and An annular one-way air flow control member, surrounding the cylinder block; wherein a return air chamber is formed among the spacer sleeve, the cylinder block and the housing near the exhaust side end, the cylinder block further has a plurality of first channels disposed near the exhaust side end and a plurality of second channels disposed near the spacer sleeve, the first channels are used for communicating the exhaust chamber with the return air chamber, and the second channels are used for communicating the intake chamber with the return air chamber; the annular one-way air flow control member covers all the second channels for preventing the air flow in the return air chamber from flowing to the intake chamber.

3. The cylinder unit for a nail gun according to claim 2, wherein: Among them, the annular buffer member further has a first tapered surface and a second tapered surface respectively connected to both sides of the first contact surface, the first tapered surface faces the exhaust chamber, and the second tapered surface faces away from the exhaust chamber, the first channels are disposed at positions where the first tapered surface faces the side wall of the cylinder block.

4. The cylinder unit for a nail gun according to claim 1, wherein: Among them, the cylinder block has a plurality of first reinforcing ribs surrounding the outer wall of the cylinder block and a plurality of second reinforcing ribs parallel to the axis of the cylinder block, the first reinforcing ribs are annular or spiral, and the second reinforcing ribs intersect with the first reinforcing ribs.

5. A nail gun, characterized in that, Comprising: A housing; and A cylinder unit, mounted within the housing for providing power to strike a nail under the action of high-pressure gas, Among them, the cylinder unit is the cylinder unit for a nail gun according to any one of claims 1-4.

6. A nail gun according to claim 5, wherein, It further includes: A control valve unit, which is provided as an external component of the cylinder unit on the intake side end of the cylinder unit.

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