Pneumatic nail gun

Abstract

The application discloses a pneumatic nail gun and belongs to the technical field of electric tools. The pneumatic nail gun comprises a machine body and a nail feeding device. The machine body is provided with a cylinder assembly and a driving assembly. The cylinder assembly comprises a first cylinder, a second cylinder, a striker and a locking structure. The first cylinder comprises a cylinder shell, a first piston and a first chamber. The first piston has a front limit position and a rear limit position. The second cylinder comprises a cylinder barrel, a second piston and a second chamber. The striker and the second piston have synchronous initial positions and nailing positions. An air inlet gap is arranged between the cylinder shell and the first piston in the front limit position, so that external air flows into the first chamber of the first cylinder through the air inlet gap. The air inlet of the first chamber can be realized without opening a hole in the side wall of the cylinder shell, the air inlet efficiency of the first chamber can be improved, and the nailing effect is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric tools, in particular to a pneumatic nail gun. BACKGROUND

[0002] The nail gun is a hand-held nailing tool, which drives nails into wood and other objects by a fast-moving hammer. According to the different driving sources, the nail gun can be divided into electric nail gun, pneumatic nail gun, manual nail gun, etc. The existing pneumatic nail gun generally adopts a double-cylinder structure. When a large piston in a large cylinder moves, the air in the large cylinder is compressed to a certain extent. Then, the small piston in the small cylinder is released. The compressed air in the large cylinder flows into the small cylinder through the air flow channel and drives the small piston to move quickly. The small piston moving quickly drives the hammer to move synchronously. The hammer moving quickly drives nails into wood and other objects, achieving the purpose of nailing.

[0003] In order to realize the air intake of the large cylinder, the existing structure generally opens an air inlet hole on the side wall of the cylinder shell. When the large piston is at the air inlet position, the external air can flow into the large cylinder through the air inlet hole. Because the air inlet hole on the side wall of the cylinder shell is small, the air intake efficiency of the large cylinder is low. If the nailing speed is fast, the air intake amount of the large cylinder is small each time. The large cylinder does not have enough air to be compressed, which is easy to cause the nailing force to be insufficient or the nailing depth to be shallow, which is not conducive to meeting the nailing requirements. SUMMARY

[0004] In order to solve the above-mentioned shortcomings and deficiencies in the prior art, the present application provides a pneumatic nail gun. An air intake gap is arranged between the cylinder shell and the first piston at the limit position. The external air can flow into the first cylinder through the air intake gap, which greatly improves the air intake efficiency of the first chamber and is conducive to increasing the nailing force and the nailing depth.

[0005] In order to achieve the above technical purpose, the pneumatic nail gun provided by the present application comprises a machine body and a nail feeding device. The machine body is provided with a cylinder assembly and a driving assembly. The cylinder assembly comprises a first cylinder, a second cylinder, a hammer and a locking structure. The first cylinder comprises a cylinder shell, a first piston driven by the driving assembly and a first chamber formed by the cooperation of the first piston and the cylinder shell. The first piston has a front limit position and a rear limit position relative to the cylinder shell. The second cylinder comprises a cylinder barrel, a second piston arranged in the cylinder barrel and a second chamber formed by the cooperation of the second piston and the cylinder barrel. The hammer is connected to the second piston and both have synchronous initial position and nailing position. The locking structure limits the second piston at the initial position during the movement of the first piston from the front limit position to the rear limit position. An air intake gap is arranged between the cylinder shell and the first piston at the front limit position, so that the external air flows into the first chamber of the first cylinder through the air intake gap.

[0006] Preferably, the first piston has an outer diameter smaller than the inner diameter of the cylinder shell, and the intake gap is located between the outer peripheral wall of the first piston and the inner peripheral wall of the cylinder shell.

[0007] Preferably, the outer peripheral positioning sleeve of the first piston is provided with a first sealing ring in interference fit with the inner peripheral wall of the cylinder shell, and the front end of the cylinder shell is provided with a relief structure for allowing at least a part of the first sealing ring to be separated from the inner peripheral wall of the cylinder shell.

[0008] Preferably, the relief structure comprises a conical surface provided at the front end of the inner peripheral wall of the cylinder shell, the conical surface is arranged in a manner that the front end is larger than the rear end, and the inner diameter of the conical surface is larger than the outer diameter of the first sealing ring, and the first sealing ring is separated from the conical surface when the first piston is in the front limit position.

[0009] Preferably, the relief structure comprises a groove provided at the front end of the inner peripheral wall of the cylinder shell, the groove has a groove depth larger than the interference fit amount between the first sealing ring and the inner peripheral wall of the cylinder shell, and the first sealing ring is separated from the groove wall corresponding to the groove when the first piston is in the front limit position.

[0010] Preferably, the relief structure comprises a notch provided at the front end of the cylinder shell, and the first sealing ring is separated from the cylinder shell when the first piston is in the front limit position.

[0011] Preferably, the outer peripheral positioning sleeve of the first piston is provided with a first sealing ring in interference fit with the inner peripheral wall of the cylinder shell, and the first piston is partially extended out of the cylinder shell when the first piston is in the front limit position, so that the first sealing ring is separated from the cylinder shell when the first piston is in the front limit position.

[0012] Preferably, the first piston has an outer diameter smaller than the inner diameter of the cylinder shell, the outer peripheral positioning sleeve of the first piston is provided with a first sealing ring in interference fit with the inner peripheral wall of the cylinder shell, the first piston is completely extended out of the cylinder shell when the first piston is in the front limit position, and the intake gap is located between the rear end of the first piston and the front end of the cylinder shell.

[0013] Preferably, the front end of the inner peripheral wall of the cylinder shell is provided with a conical surface for guiding the first piston into the cylinder shell.

[0014] Preferably, the second cylinder is arranged in the first cylinder, the cylinder barrel penetrates through the first piston, the locking structure is arranged in the rear end of the cylinder shell, the cylinder barrel is provided with a vent hole for communicating the first chamber and the second chamber, at least a part of the vent hole is located behind the second piston in the initial position, so that the compressed air in the first chamber flows into the second chamber through the vent hole and acts on the second piston to drive the second piston to move from the initial position to the driving position.

[0015] After the above technical scheme is adopted, the present application has the following advantages:

[0016] 1. The pneumatic nail gun provided by the application, when the first piston is in the extreme position, the cylinder shell and the first piston are provided with an air inlet gap, external air can directly flow into the first chamber of the first cylinder through the air inlet gap, the air inlet efficiency of the first chamber can be greatly improved, sufficient air in the first chamber can be compressed, the air pressure of the cylinder assembly on the second piston during nailing can be reasonably increased, the speed of the striker during nailing can be reasonably increased, the nailing force and the nailing depth during continuous nailing can be increased, and the nailing effect can be improved.

[0017] 2. When the first piston is in the front extreme position, the air inlet gap is located between the outer peripheral wall of the first piston and the inner peripheral wall of the cylinder shell, at this time, the first piston can form the air inlet gap without completely separating from the cylinder shell, and the movement stability of the first piston can be improved.

[0018] 3. The front end of the cylinder shell is provided with a avoiding structure, at least part of the first sealing ring is separated from the inner peripheral wall of the cylinder shell due to the avoiding structure when the first piston is in the front extreme position, that is, at least part of the first sealing ring is not in contact with the inner peripheral wall of the cylinder shell due to the avoiding structure, the air inlet gap between the outer peripheral wall of the first piston and the inner peripheral wall of the cylinder shell can be in smooth communication with external air, and the first chamber can be smoothly filled with air. The structure of the cylinder shell is reasonably arranged, and external air can smoothly flow into the first chamber through the air inlet gap.

[0019] 4. In the first specific structure, the avoiding structure is a conical surface arranged at the front end of the inner peripheral wall of the cylinder shell, since the inner diameter of the conical surface is greater than the outer diameter of the first sealing ring, the first sealing ring is not in contact with the conical surface when the first piston and the first sealing ring are in the front extreme position, the air inlet gap can be in smooth communication with external air, and external air can smoothly flow into the first chamber through the air inlet gap.

[0020] 5. In the second specific structure, the avoiding structure is a groove arranged at the front end of the inner peripheral wall of the cylinder shell, since the depth of the groove is greater than the interference fit between the first sealing ring and the inner peripheral wall of the cylinder shell, part of the first sealing ring corresponding to the groove is not in contact with the groove wall when the first piston and the first sealing ring are in the front extreme position, the air inlet gap can be in smooth communication with external air through the groove, and external air can smoothly flow into the first chamber through the air inlet gap.

[0021] 6. In the third specific structure, the avoiding structure is a notch arranged at the front end of the cylinder shell, part of the first sealing ring corresponding to the notch is exposed to the notch when the first piston and the first sealing ring are in the front extreme position, that is, part of the first sealing ring corresponding to the notch is not in contact with the inner peripheral wall of the cylinder shell, the air inlet gap can be in communication with external air through the notch, and external air can smoothly flow into the first chamber through the air inlet gap.

[0022] 7、When the first piston and the first sealing ring are in the front limit position, the first piston partially extends out of the cylinder shell, the first sealing ring is separated from the cylinder shell along with the first piston, and the first sealing ring is not in contact with the inner circumferential wall of the cylinder shell, so that the air inlet gap can be smoothly connected with the external air, and the external air can flow into the first chamber through the air inlet gap.

[0023] 8、When the first piston and the first sealing ring are in the front limit position, the first piston completely extends out of the cylinder shell, and the first sealing ring is separated from the cylinder shell along with the first piston. At this time, the air inlet gap is located between the rear end of the first piston and the front end of the cylinder shell. Reasonably setting the specific position relationship of the first piston relative to the cylinder shell in the front limit position can smoothly form the air inlet gap between the first piston and the cylinder shell.

[0024] 9、The front end of the inner circumferential wall of the cylinder shell is provided with a conical surface. When the first piston extending out of the cylinder shell moves from the front limit position to the rear limit position, the first piston can smoothly re-enter the cylinder shell under the guidance of the conical surface. The conical surface reduces the difficulty of the first cylinder re-entering the cylinder shell and improves the movement stability of the first piston, thereby being beneficial to improving the stability of the pneumatic nail gun.

[0025] 10、When the second cylinder is arranged in the first cylinder, the cylinder barrel of the second cylinder is provided with a vent hole. The compressed air in the first chamber can directly flow into the second chamber through the vent hole and act on the second piston. In this way, the effective contact area of the compressed air acting on the second piston can be reasonably increased, so that the second piston can obtain a larger initial force, the initial speed of the second piston after being released by the locking structure to drive the striker to move can be improved, thereby improving the speed of the second piston driving the striker when nailing, which is beneficial to increasing the nailing depth, is also beneficial to nailing the nail into a harder object, and is beneficial to improving the user experience. In addition, since the compressed air in the first chamber can directly flow into the second chamber through the vent hole, there is no need to provide a channel structure on the locking structure or other components for the compressed air to flow from the first chamber to the second chamber, which is beneficial to reducing the structural difficulty and air tightness requirement of the related components. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a whole machine diagram of the pneumatic nail gun of the first embodiment.

[0027] Figure 2 It is an internal structure diagram of the machine body in the pneumatic nail gun of the first embodiment.

[0028] Figure 3 It is a structure diagram of the cylinder assembly in the pneumatic nail gun of the first embodiment when the first piston is in the front limit position.

[0029] Figure 4 It is a structure diagram of the cylinder assembly in the pneumatic nail gun of the first embodiment when the first piston is in the rear limit position.

[0030] Figure 5 Figure 1 is a partial view of the cylinder housing of the pneumatic nailer of Example One in cooperation with the first piston in the forward limit position;

[0031] Figure 6 Figure 2 is a partial view of the cylinder assembly of the pneumatic nailer of Example One in the second piston in the initial position;

[0032] Figure 7 Figure 3 is a partial view of the cylinder assembly of the pneumatic nailer of Example One in the second piston released by the locking structure;

[0033] Figure 8 Figure 4 is a partial view of the locking structure of the pneumatic nailer of Example One in cooperation with the second cylinder;

[0034] Figure 9 Figure 5 is a view of the drive assembly of the pneumatic nailer of Example One;

[0035] Figure 10 Figure 6 is a view of the cylinder housing of the pneumatic nailer of Example Two;

[0036] Figure 11 Figure 7 is a partial view of the cylinder housing of the pneumatic nailer of Example Two in cooperation with the first piston in the forward limit position;

[0037] Figure 12 Figure 8 is a view of the cylinder housing of the pneumatic nailer of Example Three;

[0038] Figure 13 Figure 9 is a partial view of the cylinder housing of the pneumatic nailer of Example Three in cooperation with the first piston in the forward limit position;

[0039] Figure 14 Figure 10 is a view of the cylinder assembly of the pneumatic nailer of Example Four;

[0040] Figure 15 Figure 11 is a partial view of the cylinder housing of the pneumatic nailer of Example Four in cooperation with the first piston in the forward limit position;

[0041] Figure 16 Figure 12 is a partial view of the cylinder housing of the pneumatic nailer of Example Six in cooperation with the first piston in the forward limit position.

[0042] In the drawings: 100 - body,

[0043] 200 - nail feed assembly,

[0044] 300 - cylinder assembly, 310 - first cylinder, 311 - cylinder shell, 3111 - conical surface, 3112 - transition surface, 3113 - groove, 3114 - notch, 312 - first piston, 313 - first chamber, 314 - intake gap, 315 - cylinder base, 316 - first sealing ring, 317 - third sealing ring, 318 - pin rod, 319 - support column, 320 - second cylinder, 321 - cylinder barrel, 3211 - vent hole, 3212 - closed end, 3213 - small hole, 322 - second piston, 323 - second chamber, 324 - second sealing ring, 325 - plug, 326 - shock pad, 327 - elastic valve sleeve, 330 - striker, 340 - locking structure, 341 - fixed seat, 342 - lock sleeve, 3421 - notch, 343 - lock core, 3431 - lock groove, 344 - sliding block, 3441 - step portion, 3442 - through groove, 3443 - second inclined surface, 345 - nut, 346 - spring, 347 - elastic pad, 348 - cover, 3481 - avoiding groove, 349 - top rod, 3491 - first inclined surface, 350 - rod body,

[0045] 400 - drive assembly, 410 - motor, 420 - speed reducer, 421 - output shaft, 430 - crank, 440 - connecting rod,

[0046] 500 - machine shell, 510 - handle part. DETAILED DESCRIPTION

[0047] The application will be further described below in conjunction with the drawings and specific embodiments. It should be understood that the following "upper", "lower", "left", "right", "longitudinal", "transverse", "inner", "outer", "vertical", "horizontal", "top", "bottom" and other words indicating the orientation or positional relationship are only based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices / components must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the application.

[0048] Example one

[0049] In combination Figures 1 to 9The pneumatic nail gun provided by the embodiment one of the present application comprises a body 100 and a nail feeding device 200, the body 100 is provided with a cylinder assembly 300 and a driving assembly 400, the cylinder assembly 300 comprises a first cylinder 310, a second cylinder 320, a striker 330 and a locking structure 340. The first cylinder 310 comprises a cylinder shell 311, a first piston 312 driven by the driving assembly 400, a first chamber 313 formed by the first piston 312 and the cylinder shell 311, and the first piston 312 has a front limit position and a rear limit position relative to the cylinder shell 311. The second cylinder 320 comprises a cylinder barrel 321, a second piston 322 arranged in the cylinder barrel 321, a second chamber 323 formed by the second piston 322 and the cylinder barrel 321, the striker 330 is connected to the second piston 322 and both have a synchronous initial position and a nailing position, and the locking structure 340 limits the second piston 322 at the initial position during the movement of the first piston 312 from the front limit position to the rear limit position. The cylinder shell 311 and the first piston 312 at the front limit position are provided with an air inlet gap 314, so that external air flows into the first chamber 313 of the first cylinder 310 through the air inlet gap 314.

[0050] The external air can directly flow into the first chamber of the first cylinder through the air inlet gap, which can greatly improve the air inlet efficiency of the first chamber, ensure that there is sufficient air in the first chamber that can be compressed, reasonably increase the gas pressure force of the cylinder assembly on the second piston during nailing, thereby reasonably increasing the speed of the striker during nailing, and be beneficial to increasing the nailing force and nailing depth during continuous nailing, thereby being beneficial to improving the nailing effect.

[0051] In combination Figure 3 , Figure 4 In the embodiment, the cylinder shell 311 is in the form of a shell with an open front end and a closed rear end, and the first cylinder 310 further comprises a cylinder seat 315 arranged at the front end of the cylinder shell 311, and the cylinder shell 311 and the cylinder seat 315 are fixed together. In combination Figure 5 The outer diameter D1 of the first piston 312 is smaller than the inner diameter d1 of the cylinder shell 311, an axially positioned first sealing ring 316 is arranged on the outer periphery of the first piston 312, the first sealing ring 316 is in interference fit with the inner peripheral wall of the cylinder shell 311, that is, the outer diameter D2 of the first sealing ring 316 is greater than the inner diameter d1 of the cylinder shell 311, and the circumferential sealing fit between the first piston 312 and the cylinder shell 311 is realized through the first sealing ring 316. Specifically, the first sealing ring 316 in the embodiment is an O-shaped sealing ring, of course, the first sealing ring 316 can also be a sealing ring with multiple sealing grooves or other types of sealing rings, which are not limited here.

[0052] In combination Figure 5In the embodiment, the air intake gap 314 is located between the outer peripheral wall of the first piston 312 and the inner peripheral wall of the cylinder shell 311. In order to enable the air intake gap 314 to communicate with the external air smoothly, the front end of the cylinder shell 311 is provided with a relief structure for enabling at least part of the first sealing ring 316 to be separated from the inner peripheral wall of the cylinder shell 311. Specifically, the relief structure includes a conical surface 3111 provided at the front end of the inner peripheral wall of the cylinder shell 311. The conical surface 3111 is provided with a large front and small rear. The diameter d2 of the rear end of the conical surface 3111 is larger than the outer diameter D2 of the first sealing ring 316. The inner diameter of the front end of the cylinder shell 311 is reasonably enlarged through the conical surface 3111. When the first piston 312 and the first sealing ring 316 are in the front limit position, the first sealing ring 316 does not contact the conical surface 3111, so that the air intake gap 314 located between the outer peripheral wall of the first piston 312 and the inner peripheral wall of the cylinder shell 311 can communicate with the external air smoothly. In the embodiment, the one-side gap amount between D1 and d1 can be set to 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, etc. The one-side interference amount between D2 and d1 can be set to 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc. The difference between d2 and D2 can be set to 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc. The inclination angle γ of the conical surface 3111 relative to the cylinder shell 311 in the axial direction can be set to 0.6°, 0.7°, 0.8°, 0.9°, 1°, 1.1°, 1.2°, 1.3°, 1.4°, 1.5°, etc. Without too many limitations here, the air intake requirement can be met.

[0053] In combination Figure 5 In order to avoid the formation of a right-angle step between the conical surface 3111 and the inner peripheral wall of the cylinder shell 311, which causes the first piston 312 to be blocked during backward movement, a conical transition surface 3112 is provided between the rear end of the conical surface 3111 and the inner peripheral wall of the cylinder shell 311. The transition surface 3112 is provided with a large front and small rear. The diameter of the front end of the transition surface 3112 is consistent with the diameter d2 of the rear end of the conical surface 3111. The diameter of the rear end of the transition surface 3112 is consistent with the inner diameter d1 of the inner peripheral wall of the cylinder shell 311. In order to reasonably increase the one-side width of the air intake gap 314, the sum h of the axial heights of the conical surface 3111 and the transition surface 3112 is greater than the axial height H of the first piston 312.

[0054] In combination Figure 6 , Figure 7 In the embodiment, the outer periphery of the second piston 322 is provided with an axially positioned second sealing ring 324. The second piston 322 and the cylinder barrel 321 are sealingly matched in the circumferential direction through the second sealing ring 324. Figure 3The second cylinder 320 further comprises a plug 325 arranged at the front end of the cylinder barrel 321. The second cylinder 320 is eccentrically arranged in the first cylinder 310 and fixed to the cylinder base 315. The first piston 312 is provided with a through hole arranged eccentrically and matched with the cylinder barrel 321. The cylinder barrel 321 penetrates the first piston 312 from the through hole. The first piston 312 can move forward and backward relative to the second cylinder 320. The inner wall of the through hole or the outer wall of the cylinder barrel 321 is provided with a third sealing ring 317 for keeping the first piston 312 and the cylinder barrel 321 in circumferential sealing cooperation.

[0055] In order to realize the gas flow between the first chamber 313 and the second chamber 323, the cylinder barrel 321 is provided with a vent hole 3211 for connecting the first chamber 313 and the second chamber 323. When the second piston 322 and the second sealing ring 324 are in the initial position, at least part of the vent hole 3211 is located behind the rear end surface of the second piston 322, and the vent hole 3211 is completely located behind the second sealing ring 324. Thus, the compressed air in the first chamber 313 can flow directly into the second chamber 323 through the vent hole 3211 and act on the second piston 322, so that the second piston 322 drives the striker 330 to move forward from the initial position to the driving position. The effective contact area of the compressed air acting on the second piston 322 can be reasonably increased, so that the second piston 322 can obtain a larger initial force, and the initial speed of the second piston 322 driving the striker 330 after being released by the locking structure 340 can be improved, so that the speed of the second piston 322 driving the striker 330 when driving the nail can be improved, which is beneficial to increasing the driving depth and driving the nail into a harder object. In addition, since the compressed air in the first chamber 313 can flow directly into the second chamber 323 through the vent hole 3211 and act on the second piston 322, it is not necessary to provide a channel structure for the compressed air to flow from the first chamber 313 to the second chamber 323 on the locking structure 340 or other components, which is beneficial to reducing the structural difficulty and air tightness requirement of the related components.

[0056] In combination with the above description Figure 6The rear end of the cylinder barrel 321 is provided with an integrated closing portion 3212, the air vent hole 3211 is arranged at the rear end of the cylinder barrel 321 and located in front of the closing portion 3212, and the air vent hole 3211 is arranged in multiple along the circumference of the cylinder barrel 321. It can be understood that the air vent hole 3211 can be arranged in a reasonable shape such as a circular hole, a square hole, a rectangular hole, an oval hole, an arc-shaped hole, a triangular hole, etc. The air vent hole 3211 can simultaneously adopt several different shapes, such as any two or any three or any multiple of a circular hole, a square hole, a rectangular hole, an oval hole, an arc-shaped hole and a triangular hole. Here, the shape of the air vent hole 3211 is not limited too much. The air vent hole 3211 can be arranged in an equal interval or a non-equal interval, and the distribution of the air vent hole 3211 is not limited too much. In addition, when the second piston 322 is in the initial position, the area ratio of the air vent hole 3211 located behind the second piston 322 can be set to 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% or the like.

[0057] The rear end of the second piston 322 is provided with a damping pad 326, the rear end surface of the damping pad 326 is provided with a groove structure for the flow of compressed air, and the outer diameter of the damping pad 326 is smaller than the outer diameter of the second piston 322, so that the compressed air flowing into the second chamber 323 through the air vent hole 3211 can directly and effectively act on the top surface of the second piston 322. The groove structure includes radially distributed and interconnected radial grooves and circumferential grooves, so that the compressed air flowing into the second chamber 323 can act on the rear end surface of the second piston 322 through the groove structure. When the second piston 322 is in the initial position, part of the air vent hole 3211 is located behind the damping pad 326 in the initial position, so that the compressed air flowing into the second chamber 323 through the air vent hole 3211 can directly flow into the groove structure.

[0058] In combination with Figure 3 , Figure 8The locking structure 340 comprises a fixing seat 341 fixed in the rear end of the cylinder shell 311, a locking sleeve 342 locked on the rear end wall of the cylinder shell 311 by a nut 345 and fixed relative to the fixing seat 341, a lock core 343 movably arranged in the locking sleeve 342, a sliding block 344 arranged in the fixing seat 341 by a metal cover 348, a spring 346 arranged in the cover 348, an elastic pad 347 arranged between the fixing seat 341 and the rear end wall of the cylinder shell 311, and the striker 330 is fixedly connected with the second piston 322 or the lock core 343 through a rod 350. The rear part of the lock core 343 is provided with a ring of locking grooves 3431 matched with the sliding block 344. The sliding block 344 can slide back and forth along a certain radial direction of the fixing seat 341. One end of the spring 346 is positioned and arranged, and the other end is in abutment with the sliding block 344. The end of the sliding block 344 facing the lock core 343 is provided with a step portion 3441 matched with the locking grooves 3431 to limit the second piston 322 in the initial position. The locking sleeve 342 is provided with a notch 3421 for avoiding the sliding block 344. In the normal state, the spring 346 abuts the sliding block 344 against the lock core 343, so that the step portion 3441 and the locking grooves 3431 are in the locked state. In order to avoid air leakage, the locking structure 340 can be sealed by sealing grease or O-ring.

[0059] In combination Figure 3 , Figure 4 In order to release the second piston 322 in time, the locking structure 340 further comprises a jacking rod 349 arranged on the first piston 312 for unlocking. The rear end of the jacking rod 349 is provided with a first inclined surface 3491. The sliding block 344 is provided with a through groove 3442 for inserting the jacking rod 349. One side of the through groove 3442 is provided with a second inclined surface 3443 corresponding to the first inclined surface 3491. The cover 348 is provided with an avoiding groove 3481 for avoiding the jacking rod 349. During the movement of the first piston 312 from the front limit position to the rear limit position, the jacking rod 349 moves backward synchronously with the first piston 312 and can be inserted into the through groove 3442 through the avoiding groove 3481. The first inclined surface 3491 and the second inclined surface 3443 abut to make the sliding block 344 move away from the lock core 343 and compress the spring 346. The sliding block 344 is separated from the locking grooves 3431 of the lock core 343, achieving the purpose of unlocking.

[0060] In combination Figure 2 The machine body 100 comprises a machine shell 500 formed with a handle portion 510. The axial direction of the driving assembly 400 is perpendicular to the axial direction of the cylinder assembly 300. In combination Figure 9The drive assembly 400 includes a motor 410 and a reducer 420 fixed together. The reducer 420 includes an output shaft 421, the end of which extends into a cylinder block 315 and is fitted with a crank 430. A pin 318 is provided inside a first piston 312. A connecting rod 440 is provided between the pin 318 and the crank 430. The top end of the connecting rod 440 is fitted onto the pin 318 to achieve hinge connection with the first piston 312, and the bottom end of the connecting rod 440 is hinged to the crank 430. The drive assembly 400 drives the first piston 312 to move back and forth between a front limit position and a rear limit position via the crank 430 and the connecting rod 440. Figure 3 , Figure 4 The cylinder 321 has several small holes 3213 spaced apart at the front end, and the front end of the cylinder 321 is fitted with an elastic valve sleeve 327 for opening and closing the small holes 3213.

[0061] In the stopped state, the crank 430 and connecting rod 440 of the drive assembly 400 are in a state of... Figure 3 In the overlapping state shown, the first piston 312 is in the front limit position. At this time, the first sealing ring 316 does not contact the conical surface 3111. An air intake gap 314 is provided between the outer peripheral wall of the first piston 312 and the conical surface 3111. External air can flow into the first chamber 313 through the air intake gap 314 to ensure that there is a sufficient amount of compressible air in the first chamber 313.

[0062] During the process of the drive assembly 400 driving the first piston 312 to move backward from the front limit position via the crank 430 and connecting rod 440, when the first sealing ring 316 contacts the inner peripheral wall of the cylinder shell 311, the first chamber 313 is isolated from the outside air. As the first piston 312 continues to move backward, the first piston 312 compresses the air in the first chamber 313, and the air pressure in the first chamber 313 increases.

[0063] Combination Figure 4 When the crank 430 and connecting rod 440 move to their vertically distributed positions and aligned on the same straight line, the first piston 312 is at its rear limit position. At this time, the first inclined surface 3491 of the push rod 349 engages with the second inclined surface 3443 of the slider 344, causing the slider 344 to slide and the stepped portion 3441 to disengage from the locking groove 3431. The second piston 322 is released, and the high-pressure compressed air in the first cylinder 310 flows directly into the second chamber 323 through the vent 3211 and acts on the second piston 322. Some of the compressed air flows into the groove structure and acts on the second piston 322 through the shock-absorbing pad 326. The second piston 322, released by the slider 344, drives the firing pin 330 forward under the action of the compressed air. After the second piston 322 and the firing pin 330 move forward a certain distance, the firing pin 330 contacts the nail delivered by the nail feeding device 200 and applies force to the nail, causing the nail to disengage from the nail feeding device 200 and be driven into the wood or other objects, thus realizing the nailing action.

[0064] When the second piston 322 moves forward to contact the plug 325, the second piston 322 and the striker 330 move forward to the nailing position, at this time, the nailing action ends, the second piston 322 is located in front of the small hole 3213, and due to the larger gas pressure in the second chamber 323, the elastic valve sleeve 327 opens the small hole 3213 under the pressure difference, and the high-pressure gas in the second chamber 323 can be discharged outward through the small hole 3213. When the gas pressure in the second chamber 323 and the external gas pressure reach balance, the elastic valve sleeve 327 closes the small hole 3213, so that the second chamber 323 is isolated from the outside air.

[0065] During the process of driving assembly 400 driving the first piston 312 to move forward from the rear limit position to the front limit position, the gas pressure in the first chamber 313 and the second chamber 323 decreases, and the second piston 322 moves backward from the nailing position to the initial position under the action of negative pressure. When the second piston 322 moves backward to the initial position, the rear part of the lock core 343 is inserted into the lock sleeve 342, and the tapered surface at the rear end of the lock core 343 is in contact with the step part 3441 of the sliding block 344, so that the sliding block 344 slides away from the lock core 343 by a distance against the elastic force of the spring 346. When the second piston 322 drives the lock core 343 to move backward to the initial position, the step part 3441 corresponds to the lock groove 3431, and the sliding block 344 slides toward the lock core 343 under the action of the elastic force of the spring 346, so that the step part 3441 is inserted into the lock groove 3431, thereby limiting the second piston 322 and the striker 330 to the initial position. When the first piston 312 moves forward to the front limit position, the first sealing ring 316 is separated from the conical surface 3111, and the outer circumferential wall of the first piston 312 and the inner circumferential wall of the cylinder shell 312 form an air inlet gap 314, and the external air flows into the first chamber 313 through the air inlet gap 314, and then the next nailing action is performed.

[0066] During nailing, the compressed air in the first chamber 313 directly flows into the second chamber 323 through the air hole 3211 and acts on the second piston 322, without the need to set a passage structure for the compressed air to flow through on the fixed seat 341 and the lock sleeve 342, and the requirement for the air-tight structure on the fixed seat 341 is also appropriately reduced, which is conducive to reducing the structural difficulty and air-tightness requirement of the related components.

[0067] The nailing device 200 and other structures in the pneumatic nail gun of the embodiment can refer to the patent documents with publication numbers CN109623736A and US11478912B2, which will not be described in detail here.

[0068] It can be understood that the second cylinder 320 can also be arranged outside the first cylinder 310 and arranged side by side with the first cylinder 310, at this time, the locking structure 340 can be arranged behind the two cylinders, and a channel structure for the compressed air in the first chamber 313 to flow into the second chamber 323 is arranged between the two cylinders.

[0069] It can be understood that the cylinder barrel 322 can also cancel the arrangement of the closed end 3212.

[0070] It can be understood that the locking structure 340 can also adopt the existing magnetic attraction structure.

[0071] Embodiment two

[0072] In combination Figure 10 , Figure 11 In this embodiment, the avoidance structure includes a groove 3113 arranged at the front end of the inner circumferential wall of the cylinder shell 311, and the groove depth s of the groove 3113 is greater than the interference fit amount (D2-d1) between the first sealing ring 316 and the inner circumferential wall of the cylinder shell 311. When the first piston 312 and the first sealing ring 316 are in the front limit position, the first sealing ring 316 corresponding to the groove 3113 is partially separated from the groove wall of the groove 3113, that is, the first sealing ring 316 corresponding to the groove 3113 is not in contact with the inner wall of the cylinder shell 311, so that the air inlet gap 314 between the outer circumferential wall of the first piston 312 and the inner circumferential wall of the cylinder shell 311 can be in communication with the external air through the groove 3113. Specifically, the groove 3113 in this embodiment extends rearward from the front end face of the cylinder shell 311 and is in a long strip shape, and a plurality of grooves 3113 are arranged along the circumference of the cylinder shell 311.

[0073] The other structures of embodiment two are the same as those of embodiment one, which will not be described one by one here.

[0074] It can be understood that the groove 3113 can also be arranged in an s shape, an arc shape, or other reasonable shapes.

[0075] It can be understood that the groove 3113 can be arranged at two, three, four, five, six, or other reasonable numbers along the circumference of the cylinder shell 311.

[0076] It can be understood that in order to meet the air intake requirement, the groove 3113 needs to ensure a certain groove depth and groove width.

[0077] It can be understood that the avoidance structure can simultaneously arrange the conical surface 3111 in embodiment one and the groove 3113 in embodiment two, at this time, the groove 3113 is arranged on the conical surface 3111.

[0078] Embodiment three

[0079] In combination Figure 12 , Figure 13In the embodiment, the avoiding structure includes a notch 3114 arranged at the front end of the cylinder shell 311. When the first piston 312 and the first sealing ring 316 are in the front limit position, the part of the first sealing ring 316 corresponding to the notch 3114 is separated from the cylinder shell 311 due to being exposed to the notch 3114, i.e., the part of the first sealing ring 316 corresponding to the notch 3114 is not in contact with the inner circumferential wall of the cylinder shell 311. The air inlet gap 314 can be in communication with the external air through the notch 3114, so that the external air can flow into the first chamber 313 from the air inlet gap 314. Preferably, the height of the notch 3114 is less than the axial height H of the first piston 312. When the first piston 312 is in the front limit position, the rear end surface of the first piston 312 is located behind the rear slot wall of the notch 3114.

[0080] The other structures of the third embodiment are the same as those of the first embodiment, which will not be described herein.

[0081] It can be understood that the notch 3114 can be arranged in one, two, three or other reasonable numbers to meet the air intake requirements.

[0082] It can be understood that, in order to appropriately increase the width of the air inlet gap 314, a conical surface can be arranged on the outer circumferential wall of the first piston 312, which is large in front and small at the rear.

[0083] It can be understood that, when the first piston 312 is in the front limit position, the rear end surface of the first piston 312 can be arranged in front of or behind the rear slot wall of the notch 3114.

[0084] It can be understood that the avoiding structure can simultaneously arrange the conical surface 3111 in the first embodiment and the notch 3114 in the third embodiment. At this time, the height of the notch 3114 can be consistent with the axial height of the conical surface 3111, or slightly less than the axial height of the conical surface 3111.

[0085] It can be understood that the avoiding structure can simultaneously arrange the groove 3113 in the second embodiment and the notch 3114 in the third embodiment. At this time, the groove 3113 and the notch 3114 are distributed in a circumferential direction of the cylinder shell 311.

[0086] It can be understood that the avoiding structure can simultaneously arrange the conical surface 3111 in the first embodiment, the groove 3113 in the second embodiment and the notch 3114 in the third embodiment. At this time, the height of the notch 3114 can be consistent with the axial height of the conical surface 3111, or slightly less than the axial height of the conical surface 3111. The groove 3113 and the notch 3114 are distributed in a circumferential direction of the cylinder shell 311.

[0087] The fourth embodiment

[0088] In combination Figure 14 , Figure 15 , in the embodiment, when the first piston 312 is in the extreme position, the first piston 312 partially extends out of the cylinder shell 311, so that the first sealing ring 316 is located outside the cylinder shell 311 along with the first piston 312, the first sealing ring 316 does not contact the inner circumferential wall of the cylinder shell 311, and the air inlet gap 314 is located between the outer circumferential wall of the rear end of the first piston 312 and the inner circumferential wall of the cylinder shell 311, so that external air can flow into the first chamber 313 from the air inlet gap 314. Specifically, in the embodiment, the axial height of the cylinder shell 311 is appropriately reduced, and the cylinder shell 311 is fixed together with the cylinder seat 315 through the support column 319, that is, there is a certain front-rear spacing between the cylinder shell 311 and the cylinder seat 315, and the front-rear spacing between the two is used to provide the space required for the first piston 312 to extend out of the cylinder shell 311.

[0089] The other structures of the fourth embodiment are the same as those of the first embodiment, which will not be described here.

[0090] Embodiment five

[0091] On the basis of the fourth embodiment, in order to reduce the difficulty of the first piston 312 re-entering the cylinder shell 311, the front end of the inner circumferential wall of the cylinder shell 311 is provided with the conical surface 3111 in the first embodiment, which plays a guiding role when the first piston 312 enters the cylinder shell 311, and is beneficial to improve the movement stability of the first piston 312. In addition, when the first piston 312 is in the front extreme position, the width of the air inlet gap 314 can also be appropriately increased through the conical surface 3111, which is beneficial to improve the air inlet efficiency.

[0092] The other structures of the fifth embodiment are the same as those of the first embodiment, which will not be described here.

[0093] Embodiment six

[0094] In combination Figure 16 , in the embodiment, when the first piston 312 and the first sealing ring 316 are in the front extreme position, the first piston 312 completely extends out of the cylinder shell 311, that is, the rear end of the first piston 312 faces forward and exceeds the front end of the cylinder shell 311, at this time, the first sealing ring 316 is located outside the cylinder shell 311 along with the first piston 312, the first sealing ring 316 does not contact the inner circumferential wall of the cylinder shell 311, and the air inlet gap 314 is located between the rear end of the first piston 312 and the front end of the cylinder shell 311, so that external air can flow into the first chamber 313 from the air inlet gap 314.

[0095] The other structures of the sixth embodiment are the same as those of the first embodiment, which will not be described here.

[0096] It can be understood that, in order to reduce the difficulty of the first piston 312 re-entering the cylinder shell 311, the front end of the inner circumferential wall of the cylinder shell 311 can be provided with the conical surface 3111 in the first embodiment, which plays a guiding role when the first piston 312 enters the cylinder shell 311, and is beneficial to improve the movement stability of the first piston 312.

[0097] In addition to the preferred embodiments described above, the present application has other embodiments, and those skilled in the art can make various changes and modifications according to the present application, as long as they do not deviate from the spirit of the present application, and should belong to the scope defined in the claims of the present application.

Claims

1. A pneumatic nail gun comprising a body and a nail feeding device, the body being provided with a cylinder assembly and a driving assembly, the cylinder assembly comprising a first cylinder, a second cylinder, a striker and a locking structure, the first cylinder comprising a cylinder shell, a first piston driven by the driving assembly, a first chamber formed by the first piston and the cylinder shell, the first piston having a front limit position and a rear limit position relative to the cylinder shell, the second cylinder comprising a cylinder barrel, a second piston arranged in the cylinder barrel, a second chamber formed by the second piston and the cylinder barrel, the striker being connected to the second piston and having a synchronous initial position and a nailing position with the second piston, the locking structure limiting the second piston at the initial position during the movement of the first piston from the front limit position to the rear limit position, characterized in that, The cylinder shell is provided with an air inlet gap between the first piston in the front limit position, so that external air flows into the first chamber of the first cylinder through the air inlet gap. The second cylinder is arranged in the first cylinder, the cylinder barrel passes through the first piston, the locking structure is arranged in the rear end of the cylinder shell, the cylinder barrel is provided with a vent hole for communicating the first chamber and the second chamber, at least part of the vent hole is located behind the second piston in the initial position, so that the compressed air in the first chamber flows into the second chamber through the vent hole and acts on the second piston to drive the second piston to move from the initial position to the punching position.

2. The gas-operated nail gun of claim 1, wherein, The outer diameter of the first piston is smaller than the inner diameter of the cylinder shell, and the air inlet gap is located between the outer peripheral wall of the first piston and the inner peripheral wall of the cylinder shell.

3. The gas-operated nail gun of claim 2, wherein, The outer peripheral positioning sleeve of the first piston is provided with a first sealing ring in interference fit with the inner peripheral wall of the cylinder shell, and the front end of the cylinder shell is provided with a avoiding structure for making at least part of the first sealing ring away from the inner peripheral wall of the cylinder shell.

4. The gas-operated nail gun of claim 3, wherein, The avoiding structure includes a conical surface arranged at the front end of the inner peripheral wall of the cylinder shell, the conical surface is arranged from large front to small rear, and the inner diameter of the conical surface is larger than the outer diameter of the first sealing ring, and the first sealing ring is away from the conical surface when the first piston is in the front limit position.

5. The gas-operated nail gun of claim 3, wherein, The avoiding structure includes a groove arranged at the front end of the inner peripheral wall of the cylinder shell, the groove depth is greater than the interference fit amount between the first sealing ring and the inner peripheral wall of the cylinder shell, and the first sealing ring is partially away from the groove wall corresponding to the groove when the first piston is in the front limit position.

6. The gas-operated nail gun of claim 3, wherein, The avoiding structure includes a notch arranged at the front end of the cylinder shell, and the first sealing ring is partially exposed to the notch corresponding to the notch when the first piston is in the front limit position, so as to be away from the cylinder shell.

7. The gas-operated nail gun of claim 2, wherein, The outer peripheral positioning sleeve of the first piston is provided with a first sealing ring in interference fit with the inner peripheral wall of the cylinder shell, and the first piston in the front limit position is partially out of the cylinder shell, so that the first sealing ring is away from the cylinder shell when the first piston is in the front limit position.

8. The gas-operated nail gun of claim 1, wherein, The outer diameter of the first piston is smaller than the inner diameter of the cylinder shell, the outer peripheral positioning sleeve of the first piston is provided with a first sealing ring in interference fit with the inner peripheral wall of the cylinder shell, the first piston in the front limit position is completely out of the cylinder shell, and the air inlet gap is located between the rear end of the first piston and the front end of the cylinder shell.

9. The gas-operated nail gun according to claim 7 or 8, characterized in that The front end of the inner peripheral wall of the cylinder shell is provided with a conical surface for guiding the first piston into the cylinder shell.

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