Pneumatic nailer

Abstract

To provide a pneumatic nailing machine that can increase nailing force and nailing depth.SOLUTION: A nailing machine includes a body provided with a cylinder module and a drive module. The cylinder module includes a first cylinder, a second cylinder, a firing pin and a lock structure. The first cylinder includes a cylinder housing 311, a first piston 312 and a first chamber. The first piston has a forward limit position and a backward limit position. The second cylinder includes: a cylinder barrel, a second piston and a second chamber. The firing pin and the second piston have synchronized initial positions and nailing positions. An air-supply clearance 314 is provided between the cylinder housing and the first piston in the forward limit position to cause outside air to flow into the first chamber of the first cylinder through the air-supply clearance. Thereby air can be supplied to the first chamber without boring a hole in a side wall of the cylinder housing, thereby improving air-supply efficiency of the first chamber and becoming advantageous to improve nailing effect.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to the technical field of power tools, and in particular to pneumatic nailers. [Background technology]

[0002] A nail gun is a handy nail gun that drives nails into objects such as wood using a firing pin that moves at high speed. Depending on the power source, nail guns can be divided into electric nail guns, pneumatic nail guns, manual nail guns, etc. In general, conventional pneumatic nail guns adopt a dual cylinder structure, in which a large piston in a large cylinder moves to compress the air in the large cylinder to a certain degree, and then a piston in a small cylinder is released. Then, the compressed air in the large cylinder flows into the small cylinder through an air flow path, and moves the small piston in the small cylinder at high speed. The small piston moving at high speed simultaneously moves the firing pin, and the firing pin moving at high speed drives the nail into an object such as wood, thereby achieving the purpose of driving the nail.

[0003] In order to supply air to the large cylinder, in the conventional structure, an air supply hole is generally provided on the side wall of the cylinder housing of the large cylinder, and when the large piston is in the ventilation position, the outside air can flow into the large cylinder through the air supply hole. However, since the air supply hole on the side wall of the cylinder housing is small, the air supply efficiency of the large cylinder is low. Therefore, when the nail driving speed is high, the amount of air supplied to the large cylinder each time is small, and there is no sufficient amount of compressible air in the large cylinder. This easily leads to insufficient nail driving force and shallow nail driving depth, which is disadvantageous to meeting the nail driving requirements. Summary of the Invention [Problem to be solved by the invention]

[0004] In order to eliminate the drawbacks and defects of the prior art described above, the present invention provides a pneumatic nailer in which an air supply gap is provided between a cylinder housing and a first piston in a limit position, and external air can flow into the first cylinder through the air supply gap, thereby greatly improving the air supply efficiency of the first chamber and advantageously increasing the nail driving force and nail driving depth. [Means for solving the problem]

[0005] In order to achieve the above technical object, the pneumatic nailer provided by the present invention includes a body and a nail feeder. The body is provided with a cylinder module and a drive module. The cylinder module includes a first cylinder, a second cylinder, a firing pin, and a locking mechanism. The first cylinder includes a cylinder housing, a first piston driven by the drive module, and a first chamber formed by the engagement of the first piston with the cylinder housing. The first piston has a front limit position and a rear limit position with respect to the cylinder housing. The second cylinder includes a cylinder barrel, a second piston provided in the cylinder barrel, and a second chamber formed by the engagement of the second piston with the cylinder barrel. The firing pin is connected to the second piston, and they have an initial position and a nail driving position that are synchronous with each other. The locking mechanism restricts the position of the second piston to the initial position during the process in which the first piston moves from the front limit position to the rear limit position. An air supply gap is provided between the cylinder housing and the first piston at the front limit position, so that outside air flows into the first chamber of the first cylinder through the air supply gap.

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

[0007] Preferably, a first seal ring is positioned and fitted on an outer periphery of the first piston so as to be press-fitted into an inner periphery wall of a cylinder housing. A retraction structure is provided at a front end of the cylinder housing for removing at least a part of the first seal ring from the inner periphery wall of the cylinder housing.

[0008] Preferably, the retraction structure includes a conical surface provided at the front end of the inner circumferential wall of the cylinder housing. The conical surface is larger at the front and smaller at the rear. The inner diameter of the conical surface is larger than the outer diameter of the first seal ring. When the first seal ring is brought to its front limit position in association with the first piston, it separates from the conical surface.

[0009] Preferably, the retraction structure includes a groove provided at a front end of the inner circumferential wall of the cylinder housing. The groove depth of the groove is greater than the amount of interference fit between the first seal ring and the inner circumferential wall of the cylinder housing. When the first seal ring is brought to its front limit position in association with the first piston, the portion of the first seal ring corresponding to the groove is released from the groove wall of the groove.

[0010] Preferably, the retraction structure includes a notch provided at a front end of the cylinder housing. When the first seal ring is brought to its front limit position in association with the first piston, a portion of the first seal ring corresponding to the notch is exposed to the outside through the notch, and the first seal ring is released from the cylinder housing.

[0011] Preferably, a first seal ring is positioned and fitted on an outer periphery of the first piston, the first seal ring being press-fitted into an inner periphery of a cylinder housing. When a part of the first piston in the front limit position extends from the cylinder housing, the first seal ring, which has reached the front limit position accompanying the first piston, is released from the cylinder housing.

[0012] Preferably, the outer diameter of the first piston is smaller than the inner diameter of the cylinder housing. A first seal ring is positioned and fitted on the outer periphery of the first piston so as to be press-fitted into the inner circumferential wall of the cylinder housing. When the first piston is in the front limit position, it completely extends from the cylinder housing, and an air supply gap is located between the rear end of the first piston and the front end of the cylinder housing.

[0013] Preferably, a conical surface is provided at a front end of an inner circumferential wall of the cylinder housing to guide the first piston as it enters the cylinder housing.

[0014] Preferably, the second cylinder is provided in the first cylinder, and the cylinder barrel is inserted into the first piston. The locking structure is provided in the rear end of the cylinder housing. The cylinder barrel is provided with a vent hole for communicating the first chamber with 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, causing the second piston to move the firing pin forward from the initial position to the nail driving position. Effect of the Invention

[0015] By using the above technical solutions, the present invention has the following advantages:

[0016] 1. In the pneumatic nailer provided by the present invention, when the first piston is at the limit position, an air supply gap is provided between the cylinder housing and the first piston. The outside air can directly flow into the first chamber of the first cylinder through the air supply gap, so that the air supply efficiency of the first chamber can be greatly improved. This ensures that there is a sufficient amount of compressible air in the first chamber, so that the working force of the air pressure applied by the cylinder module to the second piston during nail driving can be reasonably increased, and the speed of the firing pin during nail driving can be reasonably improved. This is advantageous for increasing the nail driving force and nail driving depth during continuous nail driving, and is therefore beneficial for improving the nail driving effect.

[0017] 2. When the first piston is at the front limit position, the supply gap is located between the outer peripheral wall of the first piston and the inner peripheral wall of the cylinder housing. In this case, the supply gap can be formed even if the first piston does not completely separate from the cylinder housing, which is advantageous in improving the stability of the movement of the first piston.

[0018] 3. A retraction structure is provided at the front end of the cylinder housing. When the first piston is at its front limit position, at least a portion of the first seal ring is released from the inner peripheral wall of the cylinder housing by the retraction structure. That is, at least a portion of the first seal ring is not in contact with the inner peripheral wall of the cylinder housing by the retraction structure. This allows the air supply gap located between the outer peripheral wall of the first piston and the inner peripheral wall of the cylinder housing to smoothly communicate with outside air, so that air can be smoothly supplied to the first chamber. By rationally configuring the structure of the cylinder housing, outside air can smoothly flow into the first chamber through the air supply gap.

[0019] 4. In the first specific structure, the retraction structure is a conical surface provided at the front end of the inner circumferential wall of the cylinder housing. The inner diameter of the conical surface is larger than the outer diameter of the first seal ring, so that when the first piston and the first seal ring are in the front limit position, the first seal ring does not contact the conical surface. This allows the air supply gap to smoothly communicate with the outside air, ensuring that the outside air can smoothly flow into the first chamber through the air supply gap.

[0020] 5. In the second specific structure, the retraction structure is a groove provided at the front end of the inner circumferential wall of the cylinder housing. The groove depth of the groove is greater than the amount of interference fit between the first seal ring and the inner circumferential wall of the cylinder housing, so that when the first piston and the first seal ring are in the front limit position, the part of the first seal ring corresponding to the groove does not contact the groove wall of the groove. This allows the air supply gap to smoothly communicate with the outside air through the groove, ensuring that the outside air can smoothly flow into the first chamber through the air supply gap.

[0021] 6. In the third specific structure, the retraction structure is a notch provided at the front end of the cylinder housing. When the first piston and the first seal ring are in their front limit positions, a portion of the first seal ring corresponding to the notch is exposed to the outside through the notch. That is, the portion of the first seal ring corresponding to the notch is no longer in contact with the inner peripheral wall of the cylinder housing. This allows the air supply gap to communicate with the outside air through the notch, ensuring that the outside air can smoothly flow into the first chamber through the air supply gap.

[0022] 7. When the first piston and the first seal ring are in the front limit position and a part of the first piston extends from the cylinder housing, the first seal ring is separated from the cylinder housing along with the first piston, and the first seal ring is no longer in contact with the inner peripheral wall of the cylinder housing. This allows the air supply gap to smoothly communicate with the outside air, ensuring that the outside air can smoothly flow into the first chamber through the air supply gap.

[0023] 8. When the first piston and the first seal ring are in the front limit position, if the first piston fully extends from the cylinder housing, the first seal ring will detach from the cylinder housing along with the first piston. At this time, the supply gap is located between the rear end of the first piston and the front end of the cylinder housing. By rationally setting the specific positional relationship of the first piston in the front limit position with respect to the cylinder housing, the supply gap can be smoothly formed between the first piston and the cylinder housing.

[0024] 9. A conical surface is provided at the front end of the inner peripheral wall of the cylinder housing. When the first piston extending from the cylinder housing moves from the front limit position to the rear limit position, the guiding action of the conical surface allows the first piston to smoothly re-enter the cylinder housing. The conical surface reduces the difficulty of the first piston re-entering the cylinder housing, improving the stability of the first piston's movement, which is advantageous in improving the stability of nail driving by the pneumatic nailer.

[0025] 10. When the second cylinder is provided in the first cylinder, the cylinder barrel of the second cylinder is provided with a vent hole. Thus, the compressed air in the first chamber can directly flow into the second chamber through the vent hole and act on the second piston. This can reasonably increase the effective contact area when the compressed air acts on the second piston, so that the second piston can obtain a large initial acting force, and the initial speed when the second piston is released from the locking structure and moves the firing pin is improved. This can increase the speed when the second piston operates the firing pin to drive a nail, which is favorable for increasing the nail driving depth and for driving a nail into a hard object. This is favorable for 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 path structure for the compressed air to flow from the first chamber to the second chamber in the locking structure or other members. This is favorable for reducing the structural difficulty and airtightness requirements of related members. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is an overall view of a pneumatic nail driver according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing the internal structure of the body of the pneumatic nail driver of the first embodiment. [Diagram 3] FIG. 3 is a structural diagram of the cylinder module in the pneumatic nail driver of the first embodiment when the first piston is at the front limit position. [Figure 4] FIG. 4 is a structural diagram of the cylinder module in the pneumatic nail driver of the first embodiment when the first piston is at the rearmost position. [Diagram 5] FIG. 5 is a partial structural view of the engagement between the first piston and the cylinder housing in the pneumatic nailer of the first embodiment when the first piston is at the front limit position. [Figure 6] FIG. 6 is a partial structural view of the cylinder module in the pneumatic nail driver of the first embodiment when the second piston is in the initial position. [Figure 7]FIG. 7 is a partial structural view of the pneumatic nail driver of the first embodiment when the second piston is released from the lock structure. [Figure 8] FIG. 8 is a partial structural view of the lock structure and the second cylinder in the pneumatic nail driver of the first embodiment. [Figure 9] FIG. 9 is a structural diagram of the drive module in the pneumatic nail driver of the first embodiment. [Figure 10] FIG. 10 is a structural diagram of a cylinder housing in the pneumatic nail driver of the second embodiment. [Figure 11] FIG. 11 is a schematic structural diagram of the engagement between the first piston and the cylinder housing in the pneumatic nailer of the second embodiment when the first piston is at the front limit position. [Figure 12] FIG. 12 is a structural diagram of a cylinder housing in the pneumatic nail driver of the third embodiment. [Figure 13] FIG. 13 is a partial structural view of the engagement between the first piston and the cylinder housing in the pneumatic nailer of the third embodiment when the first piston is at the front limit position. [Figure 14] FIG. 14 is a structural diagram of a cylinder module in the pneumatic nail driver of the fourth embodiment. [Figure 15] FIG. 15 is a partial structural view of the fitting between the first piston and the cylinder housing in the pneumatic nailer of the fourth embodiment when the first piston is at the front limit position. [Figure 16] FIG. 16 is a partial structural view of the engagement between the first piston and the cylinder housing in the pneumatic nailer of the sixth embodiment when the first piston is at the front limit position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present invention will be further described below in combination with the drawings and specific examples. It should be understood that the terms "upper", "lower", "left", "right", "vertical", "lateral", "inner", "outer", "vertical", "horizontal", "ceiling", "bottom" and other terms indicating directions or positional relationships are merely directions or positional relationships based on the drawings, and are merely for the convenience and simplification of the description of the present invention, and do not expressly or imply that the target device / member has a specific direction or must be constructed and operated in a specific direction. Therefore, they should not be interpreted as limiting the present invention. EXAMPLES

[0028] Combining Figs. 1 to 9, the pneumatic nailer provided in the first embodiment of the present invention includes a body 100 and a nail feeder 200. The body 100 is provided with a cylinder module 300 and a driving module 400. The cylinder module 300 includes a first cylinder 310, a second cylinder 320, a firing pin 330, and a locking structure 340. The first cylinder 310 includes a cylinder housing 311, a first piston 312 driven by the driving module 400, and a first chamber 313 formed by the engagement between the first piston 312 and the cylinder housing 311. The first piston 312 has a front limit position and a rear limit position with respect to the cylinder housing 311. The second cylinder 320 includes a cylinder barrel 321, a second piston 322 provided in the cylinder barrel 321, and a second chamber 323 formed by the engagement between the second piston 322 and the cylinder barrel 321. The firing pin 330 is connected to the second piston 322, and they have an initial position and a nail driving position which are synchronized. The locking mechanism 340 restricts the position of the second piston 322 to the initial position during the process in which the first piston 312 moves from the front limit position to the rear limit position. An air supply gap 314 is provided between the cylinder housing 311 and the first piston 312 at the front limit position. Thus, the outside air flows into the first chamber 313 of the first cylinder 310 through the air supply gap 314.

[0029] Since the outside air can directly flow into the first chamber of the first cylinder through the air supply gap, the air supply efficiency of the first chamber can be greatly improved. This ensures that there is a sufficient amount of compressible air in the first chamber, so that the air pressure acting force that the cylinder module imparts to the second piston during nail driving can be reasonably increased, and the speed of the firing pin during nail driving can be reasonably improved. This is advantageous for increasing the nail driving force and nail driving depth during continuous nail driving, and is therefore beneficial for improving the nail driving effect.

[0030] 3 and 4, in this embodiment, the cylinder housing 311 is in the form of a housing with an open front end and a closed rear end. The first cylinder 310 further includes a cylinder base 315 provided at the front end of the cylinder housing 311. The cylinder housing 311 and the cylinder base 315 are fixed. In combination with FIG. 5, the outer diameter D1 of the first piston 312 is smaller than the inner diameter d1 of the cylinder housing 311. In addition, a first seal ring 316 positioned in the axial direction is fitted on the outer periphery of the first piston 312. The first seal ring 316 is tightly fitted into the inner peripheral wall of the cylinder housing 311. That is, the outer diameter D2 of the first seal ring 316 is larger than the inner diameter d1 of the cylinder housing 311, and the first seal ring 316 realizes a hermetic fit between the first piston 312 and the cylinder housing 311 in the circumferential direction. Specifically, an O-shaped seal ring is used as the first seal ring 316 in this embodiment. However, it should be appreciated that the first seal ring 316 may be other types of seal ring, such as a seal ring with multiple sealing edges, and is not intended to be overly limiting herein.

[0031] 5, in this embodiment, the air supply gap 314 is located between the outer peripheral wall of the first piston 312 and the inner peripheral wall of the cylinder housing 311. In order to allow the air supply gap 314 to smoothly communicate with the outside air, a retraction structure is provided at the front end of the cylinder housing 311 for removing at least a part of the first seal ring 316 from the inner peripheral wall of the cylinder housing 311. Specifically, the retraction structure includes a conical surface 3111 provided at the front end of the inner peripheral wall of the cylinder housing 311. The conical surface 3111 is provided so that it is larger at the front and smaller at the rear. In addition, a diameter d2 of the rear end of the conical surface 3111 is larger than an outer diameter D2 of the first seal ring 316. By rationally enlarging the inner diameter of the front end of the cylinder housing 311 by the conical surface 3111, when the first piston 312 and the first seal ring 316 are in their front limit positions, the first seal ring 316 does not come into contact with the conical surface 3111, and the air supply gap 314 located between the outer peripheral wall of the first piston 312 and the inner peripheral wall of the cylinder housing 311 can smoothly communicate with the outside air. In this embodiment, the amount of one-sided clearance between D1 and d1 may be reasonably sized, such as 0.3mm, 0.4mm, 0.5mm, 0.6mm, etc., the amount of one-sided interference between D2 and d1 may be reasonably sized, such as 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc., the difference between d2 and D2 may be reasonably sized, such as 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc., and the inclination angle γ of the conical surface 3111 relative to the axial direction of the cylinder housing 311 may be reasonably sized, such as 0.6°, 0.7°, 0.8°, 0.9°, 1°, 1.1°, 1.2°, 1.3°, 1.4°, 1.5°, etc. However, there is no excessive restriction here, as long as it can meet the air supply requirements.

[0032] 5, a conical transition surface 3112 is provided between the rear end of the conical surface 3111 and the inner peripheral wall of the cylinder housing 311 so that the rearward movement of the first piston 312 is not hindered by the formation of a right-angle step between the conical surface 3111 and the inner peripheral wall of the cylinder housing 311. The transition surface 3112 is provided so that it is larger at the front and smaller at the rear. The diameter of the front end of the transition surface 3112 is the same as the diameter d2 of the rear end of the conical surface 3111, and the diameter of the rear end of the transition surface 3112 is the same as the inner diameter d1 of the inner peripheral wall of the cylinder housing 311. In order to rationally increase the width of one side of the air supply gap 314, the sum h of the axial heights of the conical surface 3111 and the transition surface 3112 is larger than the axial height H of the first piston 312.

[0033] Combining FIG. 6 and FIG. 7, in this embodiment, a second seal ring 324 positioned in the axial direction is fitted around the outer periphery of the second piston 322. The second seal ring 324 provides a circumferentially sealed fit between the second piston 322 and the cylinder barrel 321. Combining FIG. 3, the second cylinder 320 further includes a stopper head 325 provided at the front end of the cylinder barrel 321. The second cylinder 320 is eccentrically provided inside the first cylinder 310 and fixed to the cylinder base 315. The first piston 312 is provided with a through hole that is eccentrically provided and fitted with the cylinder barrel 321. The cylinder barrel 321 is inserted into the first piston 312 through the through hole. The first piston 312 can move back and forth relative to the second cylinder 320. A third seal ring 317 is provided on the inner wall of the through hole or the outer wall of the cylinder barrel 321 to maintain a tight fit between the first piston 312 and the cylinder barrel 321 in the circumferential direction.

[0034] In order to realize the passage of gas between the first chamber 313 and the second chamber 323, the cylinder barrel 321 is provided with an air hole 3211 for communicating the first chamber 313 and the second chamber 323. When the second piston 322 and the second seal ring 324 are in the initial position, at least a part of the air hole 3211 is located behind the rear end surface of the second piston 322. Also, the air hole 3211 is completely located behind the second seal ring 324. This allows the compressed air in the first chamber 313 to directly flow into the second chamber 323 through the air hole 3211, and acts on the second piston 322, which causes the firing pin 330 to move forward from the initial position to the nail driving position. In this case, the effective contact area when the compressed air acts on the second piston 322 can be reasonably increased, so that the second piston 322 can obtain a large initial acting force, and the initial speed when the second piston 322 is released from the locking structure 340 and moves the firing pin 330 is improved. This increases the speed when the second piston 322 operates the firing pin 330 to drive a nail, which is advantageous for increasing the nail driving depth and for driving a nail into a hard object. In addition, since the compressed air in the first chamber 313 can directly flow into the second chamber 323 through the vent hole 3211 and act on the second piston 322, there is no need to provide a path structure for the compressed air to flow from the first chamber 313 to the second chamber 323 in the locking structure 340 or other members. This is advantageous for reducing the structural difficulty and airtightness requirements of related members.

[0035] 6, the rear end of the cylinder barrel 321 is provided with a contraction portion 3212 that is molded integrally. The vent hole 3211 is provided at the rear end of the cylinder barrel 321 and is located in front of the contraction portion 3212. The vent hole 3211 is provided in a plurality of spaces in the circumferential direction of the cylinder barrel 321. As can be understood, the vent hole 3211 may have a reasonable shape such as a round hole, a square hole, a rectangular hole, an elliptical hole, an arc-shaped hole, a triangular hole, etc. In addition, the vent hole 3211 may have several types of holes with different shapes at the same time, for example, any two types, any three types, or any multiple types of round holes, square holes, rectangular holes, elliptical holes, arc-shaped holes, and triangular holes are used at the same time. However, the shape of the vent hole 3211 is not excessively limited here. The vent hole 3211 may be distributed at equal intervals or may be distributed at non-equidistant intervals, and the distribution of the vent hole 3211 is not excessively limited here. In addition, when the second piston 322 is in the initial position, the proportion of the area of ​​the air hole 3211 that is located behind the second piston 322 may be a reasonable size such as 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc.

[0036] A vibration-damping pad 326 is provided at the rear end of the second piston 322. A groove structure for flowing compressed air is provided at the rear end surface of the vibration-damping pad 326. Since the outer diameter of the vibration-damping pad 326 is smaller than the outer diameter of the second piston 322, the compressed air flowing into the second chamber 323 through the vent hole 3211 can directly and effectively act on the ceiling surface of the second piston 322. The groove structure includes radial grooves and circumferential grooves that are alternately distributed and communicate with each other. This allows the compressed air flowing into the second chamber 323 to act evenly on the rear end surface of the second piston 322 through the groove structure. When the second piston 322 is in the initial position, a part of the vent hole 3211 is located behind the vibration-damping pad 326 that is also in the initial position, so that the compressed air flowing into the second chamber 323 through the vent hole 3211 can be made to flow directly into the groove structure.

[0037] 3 and 8, the lock structure 340 includes a fixed base 341 fixed in the rear end of the cylinder housing 311, a lock sleeve 342 fastened to the rear end wall of the cylinder housing 311 by a nut 345 and maintained fixed to the fixed base 341, a lock core 343 provided in the lock sleeve 342 so as to be movable back and forth, a slider 344 provided in the fixed base 341 through a metal cover 348, a spring 346 provided in the cover 348, and an elastic pad 347 provided between the fixed base 341 and the rear end wall of the cylinder housing 311. The firing pin 330 is fixedly connected to the second piston 322 or the lock core 343 via a rod body 350. A lock groove 3431 that engages with the slider 344 is provided at the rear of the lock core 343. The slider 344 can slide back and forth along any radial direction of the fixed base 341. One end of the spring 346 is fixedly installed, and the other end abuts against the slider 344. The slider 344 is provided with a step portion 3441 at one end facing the lock core 343, which engages with the lock groove 3431 to position the second piston 322 at an initial position. The lock sleeve 342 is provided with a slot opening 3421 to avoid the slider 344. In a normal state, the spring 346 biases the slider 344 toward the lock core 343, thereby locking the step portion 3441 and the lock groove 3431. To prevent air leakage, the lock structure 340 may be sealed by a combination of a seal grease, an O-ring, or the like.

[0038] 3 and 4, the locking structure 340 further includes a push rod 349 provided on the first piston 312 for unlocking, so that the locking structure 340 can quickly release the second piston 322. A first inclined surface 3491 is provided at the rear end of the push rod 349, and a through groove 3442 into which the push rod 349 is inserted is provided in the slider 344. A corresponding second inclined surface 3443 parallel to the first inclined surface 3491 is provided on one side of the through groove 3442. In addition, a retreat groove 3481 for avoiding the push rod 349 is provided in the cover 348. In the process in which the first piston 312 moves rearward from the front limit position to the rear limit position, the push rod 349 moves rearward simultaneously with the first piston 312, and can be inserted into the through groove 3442 through the retreat groove 3481. Then, the first inclined surface 3491 comes into contact with the second inclined surface 3443 to apply a force to the slider 344, moving it in a direction away from the lock core 343, and also applies a force to the spring 346 to compress it. As a result, the slider 344 is released from the lock groove 3431 of the lock core 343, thereby achieving the purpose of unlocking.

[0039] 2, the body 100 includes a casing 500. The casing 500 is formed with a handle 510. The axial direction of the driving module 400 and the axial direction of the cylinder module 300 are perpendicular to each other. 9, the driving module 400 includes a motor 410 and a reducer 420 fixed to each other. The reducer 420 includes an output shaft 421. The end of the output shaft 421 extends into the cylinder base 315 and a crank 430 is disposed thereon. A pin rod 318 is disposed in the first piston 312, and a connecting rod 440 is disposed between the pin rod 318 and the crank 430. The tip of the connecting rod 440 is covered by the pin rod 318 to realize a hinge connection with the first piston 312. The bottom end of the connecting rod 440 is hinged to the crank 430. The driving module 400 reciprocates the first piston 312 between a front limit position and a rear limit position through a crank 430 and a connecting rod 440. Combining Figures 3 and 4, the front end of the cylinder barrel 321 is provided with a number of small holes 3213 spaced apart from each other. The front end of the cylinder barrel 321 is also covered with an elastic valve sleeve 327 for opening and closing the small holes 3213.

[0040] 3, the crank 430 and the connecting rod 440 of the driving module 400 are overlapped, and the first piston 312 is in the front limit position. At this time, the first seal ring 316 is not in contact with the conical surface 3111, and an air supply gap 314 is provided between the outer peripheral wall of the first piston 312 and the conical surface 3111. In this case, outside air can flow into the first chamber 313 through the air supply gap 314, and a sufficient amount of compressible air is ensured in the first chamber 313.

[0041] In the process in which the driving module 400 moves the first piston 312 rearward from the front limit position through the crank 430 and the connecting rod 440, the first seal ring 316 comes into contact with the inner peripheral wall of the cylinder housing 311, blocking the first chamber 313 from the outside air. Then, in the process in which the first piston 312 continues to move rearward, the first piston 312 compresses the air in the first chamber 313, increasing the air pressure in the first chamber 313.

[0042] 4, when the crank 430 and the connecting rod 440 move up and down and are aligned on the same straight line, the first piston 312 is in the rear limit position. At this time, the first inclined surface 3491 of the push-up rod 349 cooperates with the second inclined surface 3443 of the slider 344 to slide the slider 344 and to separate the step portion 3441 from the lock groove 3431. This releases the second piston 322. Then, the high-pressure compressed air in the first cylinder 310 flows directly into the second chamber 323 through the vent hole 3211 and acts on the second piston 322. In addition, a part of the compressed air flows into the groove structure and acts on the second piston 322 through the vibration control pad 326. As a result, the second piston 322 released from the slider 344 moves the firing pin 330 forward by 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 comes into contact with the nail fed from the nail feeding device 200 and applies a force to the nail, causing the nail to leave the nail feeding device 200 and be driven into an object such as wood, thereby achieving a nail driving operation.

[0043] When the second piston 322 moves forward until it abuts against the stopper head 325, the second piston 322 and the firing pin 330 move forward to the nail driving position. At this time, the nail driving operation is completed and the second piston 322 is located in front of the small hole 3213. Then, since the air pressure in the second chamber 323 is high, the elastic valve sleeve 327 opens the small hole 3213 due to the action of the pressure difference, allowing the high-pressure gas in the second chamber 323 to be discharged from the small hole 3213 to the outside. Then, when the air pressure in the second chamber 323 and the external air pressure become equilibrium, the elastic valve sleeve 327 closes the small hole 3213, cutting off the second chamber 323 from the outside air.

[0044] In the process in which the driving module 400 moves the first piston 312 forward from the rear limit position through the crank 430 and the connecting rod 440 and returns it to the front limit position, the air pressure in the first chamber 313 and the second chamber 323 decreases. Therefore, the second piston 322 moves backward from the nail driving position due to the action of the negative pressure and returns to the initial position. When the second piston 322 moves backward to near the initial position, the rear part of the lock core 343 is inserted into the lock sleeve 342. Then, the conical surface at the rear end of the lock core 343 abuts against the step part 3441 of the slider 344, so that the slider 344 is first slid a certain distance away from the lock core 343 against the elastic force of the spring 346. Then, when the second piston 322 moves backward together with the lock core 343 to the initial position, the step part 3441 corresponds to the lock groove 3431. Also, the slider 344 slides toward the lock core 343 due to the action of the elastic force of the spring 346, and the stepped portion 3441 is inserted into the lock groove 3431, thereby restricting the second piston 322 and the firing pin 330 to their initial positions. When the first piston 312 moves forward to its front limit position, the first seal ring 316 disengages from the conical surface 3111, and an air supply gap 314 is formed between the outer peripheral wall of the first piston 312 and the inner peripheral wall of the cylinder housing 311. This allows outside air to flow into the first chamber 313 through the air supply gap 314, and the next nail driving operation is performed.

[0045] During nail driving, the compressed air in first chamber 313 flows directly into second chamber 323 through vent hole 3211 and acts on second piston 322, so there is no need to provide a path structure for passing compressed air in fixed base 341 or lock sleeve 342. This correspondingly reduces the requirements for the airtight structure of fixed base 341, which is advantageous in reducing the structural difficulty and airtightness requirements of related members.

[0046] For other structures of the nail feeding device 200 and the like in the pneumatic nail driver of this embodiment, reference can be made to patent documents such as Chinese Patent Application Publication No. 109623736 and U.S. Patent No. 11478912, and therefore no further detailed description will be given here.

[0047] As can be appreciated, the second cylinder 320 may be provided outside the first cylinder 310 and installed alongside the first cylinder 310. In this case, the locking structure 340 may be provided behind the two cylinders, and a path structure for allowing the compressed air in the first chamber 313 to flow into the second chamber 323 may be provided between the two cylinders.

[0048] As can be appreciated, the constriction 3212 may be omitted from the cylinder barrel 321 .

[0049] As can be appreciated, the locking structure 340 may be any conventional magnetically attractive structure. EXAMPLES

[0050] 10 and 11, in this embodiment, the retraction structure includes a groove 3113 provided at the front end of the inner peripheral wall of the cylinder housing 311. The groove depth s of the groove 3113 is greater than the interference fit (D2-d1) between the first seal ring 316 and the inner peripheral wall of the cylinder housing 311. When the first piston 312 and the first seal ring 316 are in the front limit position, the part of the first seal ring 316 corresponding to the groove 3113 is released from the groove wall of the groove 3113. That is, the part of the first seal ring 316 corresponding to the groove 3113 is no longer in contact with the inner wall of the cylinder housing 311. As a result, the air supply gap 314 located between the outer peripheral wall of the first piston 312 and the inner peripheral wall of the cylinder housing 311 can communicate with the outside air through the groove 3113. Specifically, in this embodiment, the recessed groove 3113 is elongated and extends rearward from the front end surface of the cylinder housing 311. A plurality of recessed grooves 3113 are provided at intervals in the circumferential direction of the cylinder housing 311.

[0051] The other structures in the second embodiment are similar to those in the first embodiment, and therefore will not be described in detail here.

[0052] As can be appreciated, the groove 3113 may have any other reasonable shape, such as an S-shape, an arc shape, etc.

[0053] As can be appreciated, the recessed grooves 3113 may be spaced circumferentially around the cylinder housing 311 and may be any reasonable number, such as two, three, four, five, six, etc.

[0054] As can be appreciated, in order to meet the air supply requirements, the groove 3113 must ensure a certain groove depth and groove width.

[0055] As can be understood, the conical surface 3111 of the first embodiment and the recessed groove 3113 of the second embodiment may be simultaneously provided as the retraction structure. In this case, the recessed groove 3113 is provided in the conical surface 3111. EXAMPLES

[0056] Combining FIG. 12 and FIG. 13, in this embodiment, the retraction structure includes a notch 3114 provided at the front end of the cylinder housing 311. When the first piston 312 and the first seal ring 316 are in the front limit position, the portion of the first seal ring 316 corresponding to the notch 3114 is exposed to the outside from the notch 3114 and is separated from the cylinder housing 311. That is, the portion of the first seal ring 316 corresponding to the notch 3114 is no longer in contact with the inner peripheral wall of the cylinder housing 311. As a result, the air supply gap 314 can communicate with the outside air through the notch 3114, so that the outside air can flow from the air supply gap 314 into the first chamber 313. Preferably, the height of the notch 3114 is smaller than the axial height H of the first piston 312, and 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 groove wall of the notch 3114.

[0057] The other structures in the third embodiment are similar to those in the first embodiment, and therefore will not be described in detail here.

[0058] As can be appreciated, the notches 3114 may be provided in any reasonable number, such as one, two, three, etc., to meet the air supply requirements.

[0059] As can be appreciated, in order to appropriately increase the width of the air supply gap 314, the outer peripheral wall of the first piston 312 may be provided with a conical surface located rearward of the first seal ring 316 and having a larger surface at the front and smaller surface at the rear.

[0060] As can be understood, when the first piston 312 is in the front limit position, the rear end surface of the first piston 312 and the rear groove wall of the notch 3114 may be aligned front to back. Also, it goes without saying that when the first piston 312 is in the front limit position, the rear end surface of the first piston 312 may be located in front of the rear groove wall of the notch 3114.

[0061] As can be seen, the conical surface 3111 of Example 1 and the notch 3114 of Example 3 may be provided simultaneously as the retraction structure. In this case, the height of the notch 3114 may be the same as the axial height of the conical surface 3111, or may be slightly smaller than the axial height of the conical surface 3111.

[0062] As can be understood, the recessed groove 3113 of the second embodiment and the notch 3114 of the third embodiment may be provided simultaneously as the retraction structure. In this case, the recessed groove 3113 and the notch 3114 are distributed in a circumferential direction of the cylinder housing 311 with a shift.

[0063] As can be understood, the conical surface 3111 of the first embodiment, the recessed groove 3113 of the second embodiment, and the notch 3114 of the third embodiment may be provided simultaneously as the retraction structure. In this case, the height of the notch 3114 may be the same as the axial height of the conical surface 3111, or may be slightly smaller than the axial height of the conical surface 3111. In addition, the recessed groove 3113 and the notch 3114 are distributed in a circumferentially offset manner around the cylinder housing 311. EXAMPLES

[0064] Combining FIG. 14 and FIG. 15, in this embodiment, when the first piston 312 is at the front limit position, a part of the first piston 312 extends from the cylinder housing 311. At this time, the first seal ring 316 detaches from the cylinder housing 311 along with the first piston 312 and is located outside the cylinder housing 311, so that the first seal ring 316 does not contact the inner peripheral wall of the cylinder housing 311. As a result, the air supply gap 314 is located between the outer peripheral wall of the rear end of the first piston 312 and the inner peripheral wall of the cylinder housing 311, so that outside air can flow into the first chamber 313 from the air supply gap 314. Specifically, the axial height of the cylinder housing 311 in this embodiment is appropriately small. In addition, the cylinder housing 311 is fixed to the cylinder base 315 via the support pillar 319 with a gap therebetween. That is, there is a certain front-rear gap between the cylinder housing 311 and the cylinder base 315. The front to back spacing between them is used to provide the space required for the first piston 312 to extend out of the cylinder housing 311 .

[0065] The other structures in the fourth embodiment are similar to those in the first embodiment, and therefore will not be described in detail here. EXAMPLES

[0066] Based on the fourth embodiment, in order to reduce the difficulty when the first piston 312 re-enters the cylinder housing 311, the front end of the inner peripheral wall of the cylinder housing 311 is provided with the conical surface 3111 of the first embodiment. The conical surface 3111 acts as a guide when the first piston 312 re-enters the cylinder housing 311, which is advantageous for improving the stability of the movement of the first piston 312. In addition, when the first piston 312 is at the front limit position, the conical surface 3111 can also appropriately increase the width of the air supply gap 314, which is advantageous for improving the air supply efficiency.

[0067] The other structures in the fifth embodiment are similar to those in the first embodiment, and therefore will not be described in detail here. EXAMPLES

[0068] 16, in this embodiment, when the first piston 312 and the first seal ring 316 are in the front limit position, the first piston 312 completely extends from the cylinder housing 311. That is, the rear end surface of the first piston 312 protrudes forward from the front end surface of the cylinder housing 311. At this time, the first seal ring 316 detaches from the cylinder housing 311 together with the first piston 312 and is positioned outside the cylinder housing 311, so that the first seal ring 316 does not contact the inner peripheral wall of the cylinder housing 311. As a result, the air supply gap 314 is positioned between the rear end of the first piston 312 and the front end of the cylinder housing 311, so that outside air can flow into the first chamber 313 from the air supply gap 314.

[0069] The other structures in the sixth embodiment are similar to those in the first embodiment, and therefore will not be described in detail here.

[0070] As can be seen, in order to reduce the difficulty when the first piston 312 re-enters the cylinder housing 311, the conical surface 3111 of the first embodiment may be provided at the front end of the inner peripheral wall of the cylinder housing 311. The conical surface 3111 provides a guiding effect when the first piston 312 re-enters the cylinder housing 311, and is therefore advantageous in improving the stability of the movement of the first piston 312.

[0071] In addition to the above preferred embodiments, the present invention also has other embodiments. Those skilled in the art can make various modifications and variations based on the present invention, and all of them are within the scope of the claims of the present invention as long as they do not deviate from the spirit of the present invention. [Explanation of symbols]

[0072] 100 Body 200 Nail feeder 300 Cylinder Module 310 No. 1 Cylinder 311 Cylinder housing 3111 Cone surface 3112 Transition Surface 3113 Groove 3114 Notch 312 First piston 313 Room 1 314 Air supply gap 315 Cylinder Base 316 First Seal Ring 317 3rd Seal Ring 318 Pin Rod 319 Support column 320 No. 2 cylinder 321 Cylinder Barrel 3211 Ventilation hole 3212 Contraction section 3213 Small hole 322 Second piston 323 Room 2 324 Second seal ring 325 Stopper Head 326 Vibration Control Pad 327 Elastic valve sleeve 330 Firing pin 340 Locking Structure 341 Fixed Base 342 Lock Sleeve 3421 Slot opening 343 Rock Core 3431 Lock groove 344 Slider 3441 Step 3442 Through groove 3443 Second Slope 345 Nut 346 Spring 347 Elastic Pad 348 Cover 3481 Evacuation ditch 349 Push-up Rod 3491 First Slope 350 Rod body 400 Drive Module 410 Motor 420 Reducer 421 Output shaft 430 Crank 440 Connecting Rod 500 Casing 510 Handle

Claims

1. a pneumatic nail driver including a body and a nail feeder, the body being provided with a cylinder module and a drive module, the cylinder module including a first cylinder, a second cylinder, a firing pin and a locking mechanism, the first cylinder including a cylinder housing, a first piston driven by the drive module, and a first chamber formed by fitting the first piston with the cylinder housing, the first piston having a front limit position and a rear limit position with respect to the cylinder housing, the second cylinder including a cylinder barrel, a second piston provided in the cylinder barrel, and a second chamber formed by fitting the second piston with the cylinder barrel, the firing pin is connected to the second piston, and they have initial and nail driving positions which are synchronous with each other, and the locking mechanism restricts the second piston to a position at the initial position during a process in which the first piston moves from the front limit position to the rear limit position; a first piston that is in the front limit position and an air supply gap is provided between the cylinder housing and the first piston that is in the front limit position, so that outside air flows into the first chamber of the first cylinder through the air supply gap.

2. The outer diameter of the first piston is smaller than the inner diameter of the cylinder housing, 2. The pneumatic nail driver according to claim 1, wherein the first piston is provided with a first hole and the second hole is provided with a second hole.

3. The pneumatic nailer according to claim 2, characterized in that a first seal ring is positioned and fitted on an outer periphery of the first piston so as to be press-fitted against an inner periphery wall of the cylinder housing, and a retraction structure is provided at a front end of the cylinder housing to separate at least a portion of the first seal ring from the inner periphery wall of the cylinder housing.

4. 4. The pneumatic nail driver according to claim 3, wherein the retraction structure includes a conical surface provided at the front end of the inner peripheral wall of the cylinder housing, the conical surface being larger at the front and smaller at the rear, the inner diameter of the conical surface being larger than the outer diameter of the first seal ring, and the first seal ring associated with the first piston reaching the front limit position is disengaged from the conical surface.

5. 4. The pneumatic nail driver according to claim 3, wherein the retraction structure includes a groove provided at a front end of an inner circumferential wall of the cylinder housing, the groove depth of the groove being greater than an amount of interference fit between the first seal ring and the inner circumferential wall of the cylinder housing, and the first seal ring associated with the first piston and reaching the front limit position is disengaged from the groove wall of the groove at a portion corresponding to the groove.

6. 4. The pneumatic nail driver according to claim 3, wherein the retraction structure includes a notch provided at a front end of the cylinder housing, and the first seal ring associated with the first piston and positioned at the front limit position is exposed to the outside through the notch at a portion corresponding to the notch, thereby detaching from the cylinder housing.

7. 3. The pneumatic nailer according to claim 2, wherein a first seal ring is positioned and fitted tightly to an inner peripheral wall of the cylinder housing on an outer periphery of the first piston, and when a part of the first piston in the front limit position extends from the cylinder housing, the first seal ring, which has reached the front limit position associated with the first piston, is released from the cylinder housing.

8. 2. The pneumatic nailer according to claim 1, wherein an outer diameter of the first piston is smaller than an inner diameter of the cylinder housing, a first seal ring is positioned and fitted on an outer periphery of the first piston so as to be press-fitted into an inner circumferential wall of the cylinder housing, and when the first piston in the front limit position is fully extended from the cylinder housing, the air supply gap is located between a rear end of the first piston and a front end of the cylinder housing.

9. 9. The pneumatic nail driver according to claim 7, wherein a conical surface is provided at a front end of an inner peripheral wall of the cylinder housing to guide the first piston when it enters the cylinder housing.

10. 2. The pneumatic nailer according to claim 1, wherein the second cylinder is provided in the first cylinder, the cylinder barrel is inserted into the first piston, the locking mechanism is provided in a rear end of the cylinder housing, the cylinder barrel is provided with an air hole for communicating the first chamber with the second chamber, and at least a part of the air hole is located behind the second piston in an initial position, so that the compressed air in the first chamber flows into the second chamber through the air hole and acts on the second piston to move the firing pin forward from the initial position to the nail driving position.

Images