A 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 internally provided with a cylinder assembly, a driving assembly and a lock catch assembly. The cylinder assembly comprises a first cylinder provided with a first piston, a second cylinder provided with a second piston and a firing pin. The second cylinder comprises a cylinder barrel, and the second piston is arranged in the cylinder barrel. The second piston and the firing pin have initial positions and nailing positions. The cylinder barrel is provided with a vent hole, at least a part of the vent hole is higher than the top surface of the second piston in the initial position, so that the compressed air in the first cylinder flows into the second cylinder through the vent hole and acts on the second piston to drive the second piston to move from the initial position to the nailing position. The effective contact area of the compressed air acting on the second piston is increased, the second piston can obtain a larger initial force, the initial movement speed of the second piston driving the firing pin to move downward is improved, and thus the movement speed of the second piston driving the firing pin to nail 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 piston in a small cylinder is released. The compressed air in the large cylinder flows into the small cylinder through an air flow channel and pushes the small piston to move fast. The fast-moving small piston drives the hammer to move synchronously. The fast-moving hammer drives nails into wood and other objects to achieve the purpose of nailing. However, in the existing double-cylinder pneumatic nail gun, the structure of the air flow channel through which the compressed air flows from the large cylinder into the small cylinder is relatively complex. The air tightness of the related components is required to be relatively high. The length of the flow path of the compressed air is relatively long. Moreover, the effective contact area of the compressed air acting on the small piston is relatively small. As a result, the initial force acting on the small piston is relatively small, and the initial movement speed of the small piston is also relatively small. Therefore, the speed of the small piston driving the hammer to nail is relatively small, and the nailing depth is relatively shallow. When the object to be nailed is relatively hard, the nails cannot be effectively driven into the object, which is not conducive to improving the user experience. SUMMARY

[0003] In order to solve the above-mentioned shortcomings and deficiencies in the prior art, the present application provides a pneumatic nail gun. An air hole is arranged on the cylinder barrel of the second cylinder. The compressed air in the first cylinder can flow directly into the first cylinder through the air hole and act on the second piston, effectively increasing the nailing depth and effectively driving nails into relatively hard objects, which is conducive to improving the user experience.

[0004] In order to achieve the above technical purpose, the present application provides a pneumatic nail gun, which comprises a machine body and a nail feeding device. The machine body is internally provided with a cylinder assembly, a driving assembly, and a lock catch assembly. The cylinder assembly comprises a first cylinder provided with a first piston, a second cylinder provided with a second piston, and a hammer driven by the second piston. The first piston is driven by the driving assembly and has an air passage position and a compression position. The second cylinder is arranged in the first cylinder and penetrates the first piston. The second cylinder comprises a cylinder barrel, and the second piston is arranged in the cylinder barrel. The second piston and the hammer have an initial position and a nailing position. The lock catch assembly limits the second piston at the initial position during the movement of the first piston from the air passage position to the compression position. The cylinder barrel is provided with an air hole for communicating the inside of the first cylinder and the inside of the second cylinder. At least part of the air hole is higher than the top surface of the second piston at the initial position, so that the compressed air in the first cylinder flows into the second cylinder through the air hole and acts on the second piston to drive the second piston to move from the initial position to the nailing position.

[0005] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0006] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0007] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0008] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0009] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0010] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0011] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0012] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0013] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0014] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0015] Preferably, the vent hole is higher than the top surface of the second piston in the initial position by not less than 50% of the area ratio.

[0016] After the above technical solutions are adopted, the present application has the following advantages:

[0017] 1. The pneumatic nail gun provided by the application sets a ventilation hole communicating the interiors of the two cylinders on the cylinder barrel of the second cylinder, compressed air in the first cylinder can flow into the second cylinder directly through the ventilation hole and act on the second piston, the effective contact area of the compressed air acting on the second piston is reasonably increased, the second piston can obtain a larger initial acting force, the initial movement speed of the second piston driving the striker downward after being released by the locking buckle assembly is improved, thereby the movement speed of the second piston driving the striker when nailing is improved, which is beneficial to increasing the nailing depth and is also beneficial to nailing the nail into a harder object and improving the user experience. In addition, since the compressed air in the first cylinder can flow into the second cylinder directly through the ventilation hole and act on the second piston, a channel structure for the compressed air flowing from the first cylinder into the second cylinder does not need to be arranged on the locking buckle assembly or other components, which is beneficial to reducing the structural difficulty and air tightness requirement of the related components.

[0018] 2. When the second piston is at the initial position, at least 50% of the area of the ventilation hole is higher than the top surface of the second piston, or the ventilation hole is completely higher than the top surface of the second piston, so as to ensure the amount of compressed air flowing into the second cylinder through the ventilation hole, so that the second piston and the striker can obtain sufficient initial movement speed, which is beneficial to improving the nailing effect.

[0019] 3. The ventilation hole is preferably spaced apart along the circumference of the cylinder barrel, so that the compressed air in the first cylinder can flow into the second cylinder quickly through the ventilation hole and act on the second piston, thereby improving the movement speed of the second piston driving the striker from the initial position to the nailing position, which is beneficial to improving the nailing effect.

[0020] 4. The ventilation hole can be a single shape hole or a plurality of holes with different shapes, and the structure style of the ventilation hole is reasonably arranged to reduce the processing difficulty of the ventilation hole, which is beneficial to improving the production efficiency.

[0021] 5. When the second piston is at the initial position, the ventilation hole is higher than the sealing ring on the second piston, so that the compressed air flowing into the second cylinder through the ventilation hole can effectively act on the second piston, avoiding the situation that the compressed air flowing into the second cylinder through the ventilation hole is directly discharged and cannot effectively act on the second piston, improving the effect of the compressed air on the second piston, and being beneficial to improving the nailing effect.

[0022] 6. The top surface of the shock pad is provided with a groove structure, when the second piston is at the initial position, the compressed air flowing into the second cylinder can flow in the groove structure, further increasing the effective contact area of the compressed air acting on the second piston, which can further improve the initial acting force of the second piston, thereby further improving the movement speed of the striker when nailing, which is beneficial to improving the nailing effect.

[0023] 7. The outer diameter of the damping pad is smaller than that of the second piston, allowing the compressed air flowing into the second cylinder through the vent hole to directly and effectively act on the top surface of the second piston, ensuring the initial movement speed of the second piston and the firing pin. When the second piston is in its initial position, the vent hole is partially higher than the top surface of the damping pad, allowing the compressed air flowing into the second cylinder through the vent hole to flow quickly within the groove structure, which is beneficial for improving the effect of the compressed air on the second piston.

[0024] 8. Fill the gap between the locking sleeve and the fixed seat with sealing grease. The sealing grease will achieve an air seal between the locking sleeve and the fixed seat, and prevent compressed air from leaking from the assembly gap between the locking sleeve and the fixed seat, which would weaken the effect of compressed air on the second piston.

[0025] 9. An elastic pad is installed between the top of the fixed seat and the top wall of the first cylinder to achieve an airtight seal on the top side of the fixed seat. Alternatively, a groove cover is used to cover the slide groove, and a sealing rib is installed between the groove cover and the slide groove to achieve an airtight seal on the top side of the slide groove. Alternatively, the bottom side of the slide groove is open, and the cover is fixed to the fixed seat, avoiding slotting on the top of the fixed seat as much as possible. A reasonable design of the slider's installation structure and the fixed seat's sealing structure prevents compressed air in the first cylinder from leaking through assembly gaps, thus avoiding a decrease in compressed air pressure within the first cylinder and ensuring the effective action of compressed air on the second piston. Attached Figure Description

[0026] Figure 1 This is an overall view of the pneumatic nail gun in Example 1;

[0027] Figure 2 This is a diagram showing the internal structure of the body of the pneumatic nail gun in Example 1;

[0028] Figure 3 This is a structural diagram of the cylinder assembly in the pneumatic nail gun of Embodiment 1;

[0029] Figure 4 This is a partial structural diagram of the cylinder assembly in the pneumatic nail gun of Embodiment 1;

[0030] Figure 5 This is a partial structural diagram of the pneumatic nail gun in Embodiment 1 when the second piston is in its initial position;

[0031] Figure 6 This is a structural diagram of the second piston in the pneumatic nail gun of Embodiment 1;

[0032] Figure 7 This is a structural diagram of the cylinder barrel of the second cylinder in the pneumatic nail gun of Embodiment 1;

[0033] Figure 8 This is a structural diagram showing the fit between the cylinder barrel and the elastic valve sleeve of the second cylinder in the pneumatic nail gun of Example 1.

[0034] Figure 9 The cooperation structure diagram of the second cylinder and the lock catch assembly in the pneumatic nail gun of the first embodiment;

[0035] Figure 10 The exploded view of the slider and the cover of the lock catch assembly in the pneumatic nail gun of the first embodiment;

[0036] Figure 11 The structure diagram of the driving assembly in the pneumatic nail gun of the first embodiment;

[0037] Figure 12 The partial structure diagram of the second piston in the initial position in the pneumatic nail gun of the second embodiment;

[0038] Figure 13 The partial structure diagram of the lock catch assembly in the pneumatic nail gun of the third embodiment.

[0039] In the figure, 100 - body, 200 - nail feeding device, 300 - cylinder assembly, 310 - first cylinder, 311 - first piston, 312 - cylinder shell, 313 - cylinder seat, 314 - first sealing ring, 315 - pin rod, 316 - first through hole, 320 - second cylinder, 321 - second piston, 322 - cylinder barrel, 322a - closed end, 323 - air hole, 324 - plug, 325 - second sealing ring, 326 - avoiding hole, 327 - second through hole, 330 - striker, 340 - shock pad, 341 - radial slot, 342 - circumferential slot, 350 - rod body, 360 - elastic valve sleeve, 400 - driving assembly, 410 - motor, 420 - speed reducer, 421 - output shaft, 430 - crank, 440 - connecting rod, 500 - lock catch assembly, 510 - fixed seat, 511 - sliding groove, 512 - avoiding slot, 513 - insertion hole, 520 - lock sleeve, 521 - slot, 530 - lock core, 531 - lock slot, 540 - slider, 541 - step part, 542 - through slot, 543 - second inclined surface, 550 - nut, 560 - elastic pad, 570 - locking spring, 580 - jacking rod, 581 - first inclined surface, 591 - cover, 592 - slot cover, 593 - sealing rib, 594 - air-tight ring, 600 - machine shell, 610 - handle part. DETAILED DESCRIPTION

[0040] The application will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following "up", "down", "left", "right", "longitudinal", "transverse", "inner", "outer", "vertical", "horizontal", "top", "bottom" and other words indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device / element referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0041] Embodiment one

[0042] In combination Figures 1 to 11 , the pneumatic nail gun provided by the embodiment one of the application comprises a body 100 and a nail feeding device 200, the body 100 is internally provided with a cylinder assembly 300, a driving assembly 400 and a locking assembly 500, the cylinder assembly 300 comprises a first cylinder 310 provided with a first piston 311, a second cylinder 320 provided with a second piston 321 and a striker 330 driven by the second piston 321, the first piston 311 is driven by the driving assembly 400 and has a ventilation position and a compression position, the second cylinder 320 is arranged in the first cylinder 310 and penetrates through the first piston 311, the second cylinder 320 comprises a cylinder barrel 322, the second piston 321 is arranged in the cylinder barrel 322, the second piston 321 and the striker 330 have an initial position and a nailing position, and the locking assembly 500 limits the second piston 321 at the initial position during the movement of the first piston 311 from the ventilation position to the compression position. The cylinder barrel 322 is provided with a ventilation hole 323 for communicating the inside of the first cylinder 310 and the inside of the second cylinder 320, at least part of the ventilation hole 323 is higher than the top surface of the second piston 321 at the initial position, so that the compressed air in the first cylinder 310 flows into the second cylinder 320 through the ventilation hole 323 and acts on the second piston 321 to drive the second piston 321 to move the striker 330 from the initial position to the nailing position.

[0043] The compressed air in the first cylinder 310 can directly flow into the second cylinder 320 through the ventilation hole 323 and act on the second piston 321, reasonably increasing the effective contact area of the compressed air acting on the second piston 321, so that the second piston 321 can obtain a larger initial force, improving the initial movement speed of the second piston 321 driving the striker 330 to move downward after being released by the locking assembly 500, thereby improving the movement speed of the second piston 321 driving the striker 330 from the initial position to the nailing position, 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.

[0044] In combination Figure 3 , Figure 4In the embodiment, the first cylinder 310 comprises a hollow cylinder shell 312 and a cylinder base 313 arranged at the bottom end of the cylinder shell 312, and the first piston 311 is sleeved with the axially positioned first sealing ring 314 through the slot position in the circumferential direction, and the first piston 311 can move up and down in the first cylinder 310 under the driving action of the driving assembly 400. The second cylinder 320 is eccentrically fixed on the cylinder base 313, and the second cylinder 320 further comprises a plug 324 inserted into the bottom end of the cylinder barrel 322, the first piston 311 is provided with a through port arranged eccentrically and matched with the cylinder barrel 322, and the cylinder barrel 322 of the second cylinder 320 passes through the first piston 311 from the through port, that is, the first piston 311 can move up and down relative to the second cylinder 320, and the inner wall of the through port is provided with an O-shaped sealing ring for sealing cooperation between the first piston 311 and the cylinder barrel 322.

[0045] In combination Figure 5 The circumferential direction of the second piston 321 is sleeved with the axially positioned second sealing ring 325 through the slot position, and the sealing cooperation between the second piston 321 and the cylinder barrel 322 in the circumferential direction is realized through the second sealing ring 325. In order to enable the compressed air flowing into the second cylinder 320 to effectively act on the second piston 321, when the second piston 321 is in the initial position, the air passage 323 is higher than the second sealing ring 325 which is also in the initial position, so as to avoid the compressed air flowing into the second cylinder 320 through the air passage 323 from being directly discharged and unable to effectively act on the second piston 321.

[0046] In combination Figure 7 The top end of the cylinder barrel 322 is provided with an integral closing portion 322a, and the air passage 323 is arranged at the upper end of the cylinder barrel 322 and is lower than the closing portion 322a. In order to enable the compressed air in the first cylinder 310 to flow into the second cylinder 320 through the air passage 323 and act on the second piston 321, the air passage 323 is arranged at intervals along the circumferential direction of the cylinder barrel 322. In the embodiment, the air passage 323 adopts a circular hole, and the air passage 323 is preferably distributed at equal intervals along the circumferential direction of the cylinder barrel 322. It can be understood that the air passage 323 can also be arranged as a square hole, a rectangular hole, an oval hole, an arc-shaped hole, a triangular hole or other reasonable shapes of holes. Of course, the air passage 323 can also simultaneously adopt several different shapes of holes, such as simultaneously adopting any two or any three or any multiple of circular holes, square holes, rectangular holes, oval holes, arc-shaped holes and triangular holes, and the shape of the hole is not limited herein. In addition, the air passage 323 can also adopt a non-equal-interval distribution mode, that is, the central arc between adjacent two air passages 323 is different.

[0047] In combination Figure 5In order to ensure the amount of compressed air flowing into the second cylinder 320 through the vent hole 323, at least 50% of the area of the vent hole 323 is higher than the top surface of the second piston 321 when the second piston 321 is at the initial position. In the embodiment, the vent hole 323 is preferably completely higher than the top surface of the second piston 321 when the second piston 321 is at the initial position, and the lowest part of the vent hole 323 is higher than the top surface of the second piston 321 by a height difference Ah, so that 100% of the area of the vent hole 323 is higher than the top surface of the second piston 321 at the initial position. It can be understood that Ah can be set to 0.2mm, 0.5mm, 0.7mm, 1mm, 1.2mm, 1.5mm, 1.7mm, 2mm, etc. Of course, the lowest part of the vent hole 323 can also be flush with the top surface of the second piston 321 when the second piston 321 is at the initial position. Alternatively, the lowest part of the vent hole 323 can also be slightly lower than the top surface of the second piston 321 when the second piston 321 is at the initial position, so that the vent hole 323 is partially higher than the top surface of the second piston 321, and the area of the vent hole 323 higher than the top surface of the second piston 321 can be set to 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, etc. Reasonable size.

[0048] In order to slow down the impact between the second piston 321 and the locking assembly 500 when the second piston 321 is reset upward to the initial position, the top surface of the second piston 321 is provided with a shock pad 340, and the shock pad 340 is provided with a groove structure for the flow of compressed air. Figure 6 The outer diameter of the shock pad 340 is preferably smaller than the outer diameter of the second piston 321, so that the compressed air flowing into the second cylinder 320 through the vent hole 323 can directly and effectively act on the top surface of the second piston 321. The groove structure includes a plurality of circumferentially spaced radial grooves 341 and a circumferential groove 342 for communicating the radial grooves 341, so that the compressed air flowing into the second cylinder 320 can act on the top surface of the second piston 321 through the groove structure. It can be understood that the circumferential groove 342 can be an arc-shaped groove or a ring-shaped groove, and the circumferential groove 342 can be spaced by two or three or a reasonable number of rings according to the size of the shock pad 340. Of course, the groove structure can also be set to other reasonable structures.

[0049] In combination with Figure 5, in order to make the compressed air flowing into the second cylinder 320 through the vent hole 323 flow quickly in the groove structure, when the second piston 321 is in the initial position, the partial vent hole 323 is higher than the top surface of the damping pad 340 in the initial position, so that the partial vent hole 323 lower than the top surface of the damping pad 340 is at about the same height as the groove structure, so that the compressed air flowing into the second cylinder 320 through the vent hole 323 can directly flow into the groove structure. It can be understood that when the second piston 321 and the damping pad 340 are in the initial position, the area ratio of the vent hole 323 higher than the top surface of the damping pad 340 can be set to 40%, 45%, 50%, 55%, 60% and other reasonable sizes.

[0050] In combination Figure 3 , Figure 5 , Figure 9 , the lock assembly 500 includes a fixed seat 510, a lock sleeve 520, a lock core 530, a sliding block 540, a nut 550 and a locking spring 570, the fixed seat 510 is fixed to the top end in the first cylinder 310 and located at the top of the second cylinder 320, the fixed seat 510 is provided with an elastic pad 560 between the top wall of the cylinder shell 312, the cylinder barrel 322 is formed with an avoiding hole 326 for the lock sleeve 520 to pass through on the closed end 322a, the axial cross-sectional shape of the lock sleeve 520 is generally hollow inverted T-shaped, the plate-shaped part of the lock sleeve 520 is located in the first cylinder 310 and abuts with the closed end 322a, the columnar part of the lock sleeve 520 passes through the fixed seat 510 and is locked to the top wall of the cylinder shell 312 by the nut 550. The top end of the striker 330 is provided with a rod body 350, the top end of the rod body 350 is inserted into the second piston 321, the lower end of the lock core 530 is inserted into the second piston 321 and is locked and fixed with the rod body 350 by a screw, so that the lock core 530, the rod body 350 and the second piston 321 are fixed together, and the damping pad 340 is located at the outer periphery of the lock core 530. The upper part of the lock core 530 is provided with a ring of lock grooves 531 matched with the sliding block 540, the fixed seat 510 is provided with a sliding groove 511 extending in a certain radial direction, the sliding block 540 and the locking spring 570 are arranged in the sliding groove 511, in combination Figure 9 , Figure 10 , the end of the sliding block 540 towards the lock core 530 is provided with a stepped part 541 matched with the lock groove 531 to limit the second piston 321 in the initial position, the lock sleeve 520 is provided with a notch 521 for avoiding the sliding block 540, the locking spring 570 is in a compressed state and one end is in contact with the groove wall of the sliding groove 511 and the other end is in contact with the sliding block 540, the locking spring 570 in the normal state pushes the sliding block 540 towards the lock core 530 so that the stepped part 541 and the lock groove 531 are in the locked state. In this embodiment, the top side of the sliding groove 511 is open, the sliding block 540 and the lock core 530 are metal parts, the fixed seat 510 is a plastic part, and the sliding block 540 is arranged in the sliding groove 511 through the metal cover 591.

[0051] The fixed seat 510 is provided with a hole 513 for the columnar part of the lock sleeve 520 to pass through, and the hole 513 is in clearance fit with the columnar part of the lock sleeve 520. In this embodiment, sealing grease is filled in the clearance fit between the lock sleeve 520 and the fixed seat 510, and the sealing grease is used to achieve the air tightness between the lock sleeve 520 and the fixed seat 510, so as to avoid the leakage of compressed air from the assembly gap between the lock sleeve 520 and the fixed seat 510, and the decrease of the air pressure effect of the compressed air on the second piston.

[0052] The fixed seat 510 is fixed to the top wall of the cylinder shell 312 by bolts, and the elastic pad 560 is clamped between the top surface of the fixed seat 510 and the top wall of the cylinder shell 312. The elastic pad 560 is used to achieve the air tightness on the top side of the fixed seat 510, so as to avoid the leakage of compressed air from the assembly gap of the lock buckle assembly, and the decrease of the air pressure of the compressed air in the first cylinder, which is conducive to ensuring the effect of the compressed air on the second piston 321.

[0053] In combination Figure 3 , in order to release the second piston 321 in time, the lock buckle assembly 500 further includes a top rod 580 arranged on the first piston 311 and used to unlock the lock buckle assembly 500. The top rod 580 is provided with a first inclined surface 581 on the side away from the axial center of the first piston 311. The sliding block 540 is provided with a through groove 542 for the insertion of the top rod 580. The through groove 542 is provided with a second inclined surface 543 parallel to the first inclined surface 581 on the side away from the axial center of the first piston 311. The fixed seat 510 is provided with an avoiding groove 512 for avoiding the top rod 580. The cover 591 is provided with a groove for avoiding the top rod 580. During the movement of the first piston 311 from the air passage position to the compression position, the top rod 580 moves upward synchronously with the first piston 311 and is inserted into the through groove 542 of the sliding block 540 through the avoiding groove 512. The first inclined surface 581 and the second inclined surface 543 abut to make the sliding block 540 move away from the lock cylinder 530 and make the locking spring 570 be compressed. The sliding block 540 is separated from the lock groove 531 of the lock cylinder 530, so as to achieve the unlocking purpose.

[0054] In combination Figure 2 , the machine body 100 includes a machine shell 600, and the machine shell 600 is formed with a handle part 610. The axial direction of the driving assembly 400 is substantially perpendicular to the axial direction of the cylinder assembly 300. The driving assembly 400 includes a motor 410 and a speed reducer 420 fixed together. In combination Figure 3 、 Figure 11, the reducer 420 comprises an output shaft 421, the output shaft 421 extends into the cylinder seat 313 and is sleeved with a crank 430, the first piston 311 is internally provided with a pin rod 315, the pin rod 315 is provided between the crank 430 and a connecting rod 440, the connecting rod 440 is sleeved on the pin rod 315 to be hinged with the first piston 311, and the bottom end of the connecting rod 440 is hinged with the crank 430. The driving assembly 400 drives the first piston 311 to move back and forth between the ventilation position and the compression position through the crank 430 and the connecting rod 440.

[0055] In combination Figure 2 , the cylinder shell 312 of the first cylinder 310 is provided with a plurality of first through holes 316 which are distributed at intervals and at the same height at the lower end. In combination Figure 8 , the cylinder barrel 322 is provided with a plurality of second through holes 327 which are distributed at intervals and at the same height at the lower end, and the lower end of the cylinder barrel 322 is sleeved with an elastic valve sleeve 360 for opening and closing the second through holes 327.

[0056] Under normal circumstances, the crank 430 and the connecting rod 440 of the driving assembly 400 are in Figure 11 The first piston 311 is in the ventilation position, at this time, the top surface of the first piston 311 is lower than the first through hole 316, the inside of the first cylinder 310 is communicated with the outside air through the first through hole 316, and the stepped portion 541 of the sliding block 540 is in abutment with the inner top wall of the lock groove 531 to limit the second piston 321 to the initial position.

[0057] During the upward movement of the first piston 311 driven by the driving assembly 400 through the crank 430 and the connecting rod 440, when the first sealing ring 314 is higher than the first through hole 316, the inside of the first cylinder 310 is cut off from the outside air, and during the continuous upward movement of the first piston 311, the first piston 311 compresses the air in the first cylinder 310, and the air pressure in the first cylinder 310 increases.

[0058] When the crank 430 and the connecting rod 440 move to be distributed upward and downward and located on the same straight line, the first piston 311 reaches the compression position, at this time, the first inclined surface 581 of the top rod 580 cooperates with the second inclined surface 543 of the sliding block 540 to make the sliding block 540 slide and be separated from the lock groove 531, the second piston 321 is released, the compressed air in the first cylinder 310 directly flows into the second cylinder 320 through the ventilation hole 323 and acts on the top surface of the second piston 321, part of the compressed air flows into the groove structure and acts on the top surface of the second piston 321 through the damping pad 340, the released second piston 321 drives the striker 330 to move downward under the pressure of the compressed air. During the downward movement of the second piston 321 and the striker 330, the striker 330 contacts the nail sent out by the nail feeding device 200 and applies force to the nail, so that the nail is separated from the nail feeding device 200 and is driven into wood or other objects to realize the nailing action.

[0059] When the second piston 321 moves downward to abut against the plug 324, the second piston 321 and the striker 330 move downward to a nailing position, at which time, the nailing action ends, the top surface of the second piston 321 is lower than the second through hole 327, and due to the larger air pressure in the second cylinder 320, the elastic valve sleeve 360 is opened under the action of the air pressure difference, and the high-pressure gas in the second cylinder 320 can be discharged outward through the second through hole 327. When the interior of the second cylinder 320 and the outside air reach air pressure balance, the elastic valve sleeve 360 closes the second through hole 327, so that the interior of the second cylinder 320 is cut off from the outside air.

[0060] During the process of driving the assembly 400 to drive the first piston 311 to move downward from the compression position to reset to the ventilation position, the air pressure in the first cylinder 310 and the second cylinder 320 decreases, and the second piston 321 moves upward from the nailing position to reset to the initial position under the action of negative pressure. When the second piston 321 moves upward to be close to the initial position, the upper part of the lock core 530 is inserted into the lock sleeve 520, and the conical surface at the top end of the lock core 530 abuts against the stepped portion 541 of the sliding block 540, so that the sliding block 540 slides a distance away from the lock core 530 against the elastic force of the locking spring 570. When the second piston 321 drives the lock core 530 to move upward to the initial position, the stepped portion 541 corresponds to the lock groove 531, and the sliding block 540 slides toward the lock core 530 under the action of the elastic force of the locking spring 570, so that the stepped portion 541 is inserted into the lock groove 531 and abuts against the inner top wall of the lock groove 531, thereby limiting the second piston 321 and the striker 330 to the initial position.

[0061] During nailing, since the compressed air in the first cylinder 310 directly flows into the second cylinder 320 through the ventilation hole 323 and acts on the second piston 321, it is not necessary to provide a passage structure for the compressed air to flow through on the fixed seat 510 and the lock sleeve 520, and the requirement for the air-tight structure on the fixed seat 510 is also appropriately reduced, which is beneficial to reduce the structural difficulty and air-tightness requirement of the related components.

[0062] Other structures of 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.

[0063] It can be understood that the pneumatic nail gun of the embodiment can be powered by a battery pack, or directly powered by mains through a power cord.

[0064] Embodiment two

[0065] In combination Figure 12In the embodiment, the cylinder 322 is directly in a tubular shape without the setting of the closed end 322a, which is beneficial to reduce the forming process of the cylinder 322. The lower end of the lock sleeve 520 is directly inserted into the top end of the cylinder 322.

[0066] Other structures of the second embodiment are similar to those of the first embodiment, which will not be repeated here.

[0067] The third embodiment

[0068] In combination Figure 13 In the embodiment, the elastic pad 560 is cancelled, and the groove cover 592 is used to cover the sliding groove 511, and the groove cover 592 is located at the top of the cover 591. In order to realize the air-tight sealing of the top side of the fixing seat 510, the circumferential outer wall of the groove cover 592 and the circumferential inner wall of the sliding groove 511 are provided with an elastic sealing rib 593, and the circumferential sealing fit between the groove cover 592 and the sliding groove 511 is realized through the sealing rib 593. In addition, the air-tight ring 594 is arranged between the nut 550 and the lock sleeve 520, and the fixing seat 510 and the bolt are matched. The air-tight ring 594 is compressed between the top surface of the fixing seat 510 and the top wall of the cylinder shell 312. The air-tight sealing of the top side of the fixing seat 510 is realized through the sealing rib 593 and the air-tight ring 594, so as to avoid the leakage of compressed air from the assembly gap of the lock assembly, thereby reducing the air pressure of the compressed air.

[0069] Other structures of the third embodiment are similar to those of the first embodiment, which will not be repeated here.

[0070] It can be understood that the sealing rib 593 and the air-tight ring 594 can be a sealing ring.

[0071] It can be understood that the third embodiment can be combined with the second embodiment.

[0072] The fourth embodiment

[0073] In the embodiment, the bottom side of the sliding groove 511 is open, the top side of the sliding groove 511 is closed, the sliding block 540 is arranged in the sliding groove 511 through the metal cover 591, and the cover 591 is fixed with the fixing seat 510 through the screw, so as to avoid the slot on the top surface of the fixing seat 510 as much as possible, which is beneficial to simplify the air-tight structure of the lock assembly 500. Specifically, the cover 591 is provided with an outwardly protruding lug, the lug is provided with a hole, the fixing seat 510 is provided with a screw hole, the screw hole is a blind hole, the lug abuts against the bottom surface of the fixing seat 510, and the screw for fixing the cover 591 passes through the hole on the lug and is tightly screwed into the screw hole of the fixing seat.

[0074] Other structures of the fourth embodiment are similar to those of the first embodiment, which will not be repeated here.

[0075] It can be understood that the top surface of the fixing seat 510 in the embodiment can be air-tightly sealed by the elastic pad 560 in Embodiment One or the air-tight ring 594 in Embodiment Three.

[0076] It can be understood that Embodiment Four can be combined with Embodiment Two.

[0077] 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 all should belong to the scope defined by the appended claims of the present application.

Claims

1. A pneumatic nail gun comprising a body and a nail feeding device, the body having a cylinder assembly, a driving assembly and a lock assembly, the cylinder assembly comprising a first cylinder having a first piston, a second cylinder having a second piston, and a striker driven by the second piston, the first piston being driven by the driving assembly and having a venting position and a compression position, the second cylinder being disposed in the first cylinder and passing through the first piston, the second cylinder comprising a cylinder barrel and the second piston being disposed in the cylinder barrel, the second piston and the striker having an initial position and a driving position, the lock assembly limiting the second piston at the initial position during movement of the first piston from the venting position to the compression position, characterized in that, The cylinder is provided with a vent hole for communicating the interiors of the first and second cylinders, at least a part of the vent hole is higher than the top surface of the second piston in the initial position, so that the compressed air in the first cylinder flows into the second cylinder through the vent hole and acts on the second piston to drive the second piston to move from the initial position to the position for driving the nail.

2. The gas-operated nail gun of claim 1, wherein, The area ratio of the vent hole higher than the top surface of the second piston in the initial position is not less than 50%.

3. The gas-operated nail gun of claim 1, wherein, The entire vent hole is higher than the top surface of the second piston in the initial position.

4. The gas-operated nail gun of claim 1, wherein, The vent hole is provided with a plurality of circular holes, square holes, rectangular holes, oval holes, arc-shaped holes, or triangular holes.

5. The gas-operated nail gun of claim 1, wherein, The second piston is provided with an axially positioned sealing ring in the circumferential direction, and the vent hole is higher than the top surface of the sealing ring in the initial position.

6. The gas-operated nail gun of claim 1, wherein, The top surface of the second piston is provided with a shock-absorbing pad, and the shock-absorbing pad is provided with a groove structure for the flow of compressed air.

7. The gas-operated nail gun of claim 6, wherein, The outer diameter of the shock-absorbing pad is smaller than the outer diameter of the second piston; and / or, the part of the vent hole is higher than the top surface of the shock-absorbing pad in the initial position.

8. The gas-operated nail gun of claim 6, wherein, The groove structure includes a plurality of radially distributed radial grooves and a circumferential groove for communicating the radial grooves.

9. The gas-operated nail gun of claim 1, wherein, The locking assembly includes a fixed seat arranged in the first cylinder, a lock sleeve arranged at the top of the cylinder and inserted into the fixed seat, a lock core arranged on the second piston and capable of being inserted into the lock sleeve, a sliding block slidably arranged on the fixed seat and capable of cooperating with the lock core to limit the second piston in the initial position, and sealing grease filled in the gap between the lock sleeve and the fixed seat.

10. The gas-operated nail gun of claim 9, wherein, The fixed seat is provided with a sliding groove for arranging the sliding block, the top side of the sliding groove is open, the sliding block is arranged in the sliding groove through a cover, and an elastic pad is arranged between the top of the fixed seat and the top wall of the first cylinder. Alternatively, the fixed seat is provided with a sliding groove for arranging the sliding block and a groove cover for covering the sliding groove, the top side of the sliding groove is open, the sliding block is arranged in the sliding groove through a cover, the groove cover covers the top side of the sliding groove, and an elastic sealing rib is arranged between the circumferential outer wall of the groove cover and the circumferential inner wall of the sliding groove. Alternatively, the fixed seat is provided with a sliding groove for arranging the sliding block, the bottom side of the sliding groove is open, and the sliding block is arranged in the sliding groove through a cover, and the cover and the fixed seat are fixed together.

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