Fastener driving tool

Abstract

The application discloses a fastener driving tool, and belongs to the technical field of electric tools. The fastener driving tool comprises a gas chamber, a piston, a striking piece, a lifting device, a supporting cylinder and a movable cylinder body. The movable cylinder body is arranged on the inner periphery of the supporting cylinder and can move up and down. The movable cylinder body is in circumferential sealing cooperation with the supporting cylinder. The piston is arranged in the movable cylinder body. The gas chamber comprises a first gas chamber and a second gas chamber which are not communicated with each other. The first gas chamber is located outside the movable cylinder body. The gas in the first gas chamber which is extruded drives the movable cylinder body to move downward relative to the supporting cylinder. The upward moving piston can drive the movable cylinder body to move upward relative to the supporting cylinder. The upward moving movable cylinder body extrudes the gas in the first gas chamber. The gas in the second gas chamber which is extruded can drive the piston to move downward relative to the movable cylinder body. The upward moving piston can extrude the gas in the second gas chamber. The structure is improved, the driving effect is ensured, and the user's vibration feeling is reduced.

Description

Technical Field

[0001] This invention relates to the field of power tool technology, and more particularly to fastener driving tools. Background Technology

[0002] A nail gun is a handheld nailing tool that uses a rapidly moving firing pin to drive nails into workpieces such as wood. Traditional pneumatic nail guns generally employ a dual-cylinder, dual-piston structure. The large piston in the large cylinder compresses the air within it to a certain level, releasing the piston in the small cylinder. The compressed air from the large cylinder flows through an airflow channel into the small cylinder, pushing the small piston within it. This small piston, in turn, drives the firing pin, causing it to strike the nail into the wood or other workpiece, thus achieving the nailing purpose. Traditional pneumatic nail guns typically use a crank-connecting rod...

[0003] The structure drives the large piston to move back and forth. Due to the large force deviation angle of the crank-connecting rod structure during the reciprocating motion, the large piston is prone to unstable thrust and large off-center load when the crank-connecting rod structure drives the large piston to compress gas. This can easily lead to the large piston getting stuck during the gas compression process.

[0004] Based on the above, some pneumatic nail guns (such as US11034007B2 and its predecessors) have adopted a single-piston, single-chamber structure. The gas chamber is filled with high-pressure gas. The upward-moving piston compresses the gas in the gas chamber, and the high-pressure gas in the gas chamber drives the piston to move the firing pin rapidly, thereby driving the nail into the workpiece. However, since there is only one gas chamber, it only provides one acceleration effect on the piston, which is not conducive to improving the nail-driving effect. Summary of the Invention

[0005] To address the shortcomings and deficiencies of the existing technology, this invention provides a fastener driving tool that ensures effective nailing while reducing vibration for the user.

[0006] To achieve the above technical objectives, the fastener driving tool provided by the present invention includes:

[0007] The air chamber is filled with pressurized gas.

[0008] A piston that can move up and down; the compressed gas in the chamber can drive the piston to move downward.

[0009] The striking component, whose upper end is connected to the piston, moves downward with the piston to drive the fastener to be struck into the workpiece. The lifting device is used to drive the piston and the striking component to move upward.

[0010] The fastener driving tool also includes a support cylinder and a movable cylinder, wherein...

[0011] The support cylinder is fixedly installed and extends in the vertical direction.

[0012] The movable cylinder is located on the inner circumference of the support cylinder and can move up and down. The movable cylinder and the support cylinder maintain a circumferential sealed fit. The piston is located inside the movable cylinder and can move up and down.

[0013] The air chambers include a first air chamber and a second air chamber that are not interconnected, wherein,

[0014] The first air chamber is located outside the movable cylinder. The gas compressed in the first air chamber can drive the movable cylinder to move downward relative to the support cylinder. The piston moving upward can drive the movable cylinder to move upward relative to the support cylinder. The movable cylinder moving upward compresses the gas in the first air chamber.

[0015] The second chamber is formed by the cooperation of the movable cylinder and the piston. The gas compressed in the second chamber can drive the piston to move downward relative to the movable cylinder, and the piston moving upward can compress the gas in the second chamber.

[0016] Preferably, the movable cylinder has sidewalls and a top wall at the top of the sidewalls, with at least a portion of the first air chamber located above the top wall.

[0017] Preferably, the piston, striking element, and movable cylinder have a ready position, and the movable cylinder in the ready position is completely located inside the support cylinder.

[0018] Preferably, the piston, striking element, and movable cylinder have a ready position, and the movable cylinder in the ready position is at least partially higher than the support cylinder.

[0019] Preferably, the upper part of the support cylinder is provided with a limiting part adapted to the movable cylinder body, and the movable cylinder body moving to the ready position can extend out of the support cylinder and enter the limiting part.

[0020] Preferably, the piston, striking element, and movable cylinder have an end position, and the upper end of the movable cylinder in the end position is higher than or flush with the upper end of the support cylinder.

[0021] Preferably, the piston, striking element, and movable cylinder have an end position, and the fastener driving tool further includes a shock-absorbing block fixed to the lower end of the support cylinder, with the lower end of the movable cylinder in the end position abutting against the shock-absorbing block.

[0022] Preferably, the movable cylinder has side walls and a top wall located at the top of the side walls, and the first air chamber is entirely located at the top of the movable cylinder.

[0023] Preferably, the upper end of the support cylinder is provided with a cylinder cover, and the first air chamber is formed by the support cylinder, the cylinder cover and the top wall of the movable cylinder.

[0024] Preferably, the outer diameter of the support cylinder is the same at the top and bottom; or, the support cylinder is wider at the top and narrower at the bottom and has a stepped portion, and the movable cylinder body is always not higher than the stepped portion.

[0025] Preferably, the lower end of the movable cylinder is provided with a limiting cover, and the limiting cover has an elastic block located below the piston on the side facing the movable cylinder. Both the elastic block and the limiting cover are provided with clearance holes for the impacting component to pass through.

[0026] The present invention also provides a fastener driving tool, comprising:

[0027] The air chamber is filled with pressurized gas.

[0028] A piston that can move up and down; the compressed gas in the chamber can drive the piston to move downward.

[0029] The striking component, whose upper end is connected to the piston, moves downward with the piston to drive the fastener to be struck into the workpiece.

[0030] A lifting device is used to drive the piston and striking component upwards;

[0031] The fastener driving tool also includes an inner cylinder, and the upper end of the inner cylinder is provided with a through hole;

[0032] The piston is located in the inner cylinder, and the piston and the striking element have an upper ready position and a lower end position.

[0033] The air chamber includes a first air chamber and a second air chamber. The first air chamber is located outside the inner cylinder, and the second air chamber is formed by the inner cylinder and the piston.

[0034] The piston moving from the ready position to the end position can open the through hole to connect the first air chamber with the second air chamber;

[0035] The piston moving from the end position to the ready position can close the through hole to isolate the first air chamber from the second air chamber.

[0036] Preferably, multiple through holes are provided at intervals along the circumference of the inner cylinder.

[0037] Preferably, the piston and the inner cylinder are provided with a sealing ring to maintain a circumferential sealing fit between them, and at least two sealing rings are provided at intervals between them. When the piston is in the ready position, the through hole is located between two adjacent sealing rings.

[0038] By adopting the above technical solution, the present invention has the following advantages:

[0039] 1. In the first embodiment, the fastener driving tool provided by this invention is equipped with a support cylinder and a movable cylinder. The movable cylinder divides the air chamber into a first air chamber and a second air chamber that are not interconnected. During nailing, the high-pressure gas in the first air chamber drives the movable cylinder to move downward relative to the support cylinder, and the high-pressure gas in the second air chamber drives the striking element to move downward relative to the movable cylinder. The high-pressure gas in both air chambers allows the piston to accelerate twice during nailing, which helps to increase the movement speed of the striking element, thereby improving the nailing effect. When the lifting device drives the piston and the striking element to move upward, the upward-moving piston can compress the gas in the second air chamber and also drive the movable cylinder to move upward. The upward-moving movable cylinder can compress the gas in the first air chamber. The upward-moving piston compresses the gas in both air chambers simultaneously. The pressurized gas is always located separately in the two air chambers, which can ensure the nailing force. In addition, due to the adoption of a dual-chamber structure, the impact vibration generated when the striking part comes into contact with the fastener can be buffered twice by the gas in the two chambers. This can greatly reduce the vibration caused by nailing while meeting the requirements for nailing, which is beneficial to improving the user experience.

[0040] 2. In the second embodiment, the fastener driving tool provided by this invention has a through hole at the upper end of the inner cylinder. The piston can open and close the through hole to allow the two air chambers to be connected or separated. During the piston's movement from the ready position to the finished position, the high-pressure gas in the second air chamber acts on the piston first. After the piston moves downward and opens the through hole, the high-pressure gas in the first air chamber can flow into the second air chamber through the through hole and act on the piston simultaneously. The two interconnected air chambers allow the piston to accelerate twice during nailing, which helps to increase the movement speed of the striking component, thereby improving the nailing effect. Furthermore, since there are two air chambers, the impact vibration generated when the striking component contacts the fastener can be buffered twice by the gas in the two air chambers. This can greatly reduce the vibration caused by nailing while meeting the nailing requirements, thus improving the user experience. Attached Figure Description

[0041] Figure 1 This is a complete machine diagram of the fastener driving tool in Embodiment 1;

[0042] Figure 2 This is a schematic diagram of the fastener not being driven into the workpiece in Example 1;

[0043] Figure 3 This is a schematic diagram of the fastener after it has been driven into the workpiece in Example 1;

[0044] Figure 4 This is a partial structural diagram of the fastener driving tool in Embodiment 1;

[0045] Figure 5 This is an exploded view of a portion of the structure in Example 1;

[0046] Figure 6 This is a front-to-back sectional view of the support base, guide base, and striking component in Embodiment 1;

[0047] Figure 7 This is a schematic diagram of the engagement between the lifting gear and the striking component in Example 1;

[0048] Figure 8 This is an axial sectional view of part of the structure in Embodiment 1 when the piston, striking element, and movable cylinder are in the ready position;

[0049] Figure 9 This is an axial sectional view of part of the structure in Embodiment 1 when the piston, striking element, and movable cylinder are in the final position;

[0050] Figure 10 This is an exploded view of the lifting device in Example 1;

[0051] Figure 11 This is a diagram showing the partial structure of the lifting device and the engagement structure of the latch in Embodiment 1;

[0052] Figure 12 This is an axial sectional view of a portion of the lifting device structure in Embodiment 1;

[0053] Figure 13 This is a diagram showing the working structure of the driving wheel and the driven wheel in Example 1;

[0054] Figure 14 This is a structural diagram of the drive wheel in Example 1;

[0055] Figure 15 This is a diagram showing the working structure of the cam and the latch in Example 1;

[0056] Figure 16 This is a diagram showing the working structure of the latch and the stop switch in Example 1;

[0057] Figure 17 This is an exploded view of the safety components and guide seat in Embodiment 1;

[0058] Figure 18 This is an axial sectional view of part of the structure in Example 1 when the outer cylinder body adopts an irregular structure;

[0059] Figure 19 This is an axial sectional view of a portion of the fastener-driving tool in Embodiment 2, with the piston, striking element, and movable cylinder in the ready position.

[0060] Figure 20 This is an axial sectional view of a portion of the fastener-driving tool in Embodiment 2, with the piston, striking component, and movable cylinder in their final positions.

[0061] Figure 21 This is a schematic diagram of the support cylinder and the limiting part integrally formed in Embodiment 2;

[0062] Figure 22 This is an axial sectional view of part of the fastener driving tool in Embodiment 3 when the piston, striking element, and movable cylinder are in the ready position;

[0063] Figure 23 This is an axial sectional view of a portion of the fastener-driving tool in Embodiment 3 when the piston, striking component, and movable cylinder are in the final position;

[0064] Figure 24 This is an axial sectional view of part of the structure in Embodiment 3 when the piston, striking component, and movable cylinder are in the ready position, provided that the support cylinder adopts an alternative design.

[0065] Figure 25 This is an axial sectional view of part of the structure in the ready position when the piston, striking component, and movable cylinder are in an alternative configuration for the movable cylinder in Embodiment 3.

[0066] Figure 26 This is an axial sectional view of a portion of the fastener-driving tool in Embodiment 4, with the piston and striking element in the ready position.

[0067] Figure 27 This is an axial sectional view of a portion of the fastener-driving tool in Embodiment 4 when the piston and the striking element are in the final position.

[0068] Figure 28 This is an axial sectional view of part of the structure in Embodiment 4 when the piston and striking component are in the ready position, using an alternative scheme for the inner cylinder.

[0069] In the diagram, 100 represents a fastener driving tool.

[0070] 10, 10' - air chamber, 10A, 10A' - first air chamber, 10B, 10B' - second air chamber.

[0071] 21-Piston, 211-Sealing ring, 22-Impacting element, 221-Protruding tooth, 222-Groove, 23-Support cylinder, 231-Stepped portion, 24-Moving cylinder body, 241-Side wall, 242-Top wall, 243-Limit cover, 244-Elastic block, 245-Allowing hole, 25-Base, 261-Outer cylinder body, 262-Inner cylinder body, 262a-Side cylinder wall, 262b-Top cylinder wall, 263-Through hole, 264-Sealing gasket, 27-Cylinder head, 28-Shock absorber block, 281-Center hole, 291-Limiting portion, 292-Flow groove

[0072] 31-Fastener, 32-Workpiece

[0073] 40-Lifting device, 41-Lifting gear, 42-Drive shaft, 43-Motor, 44-Reduction gearbox, 441-Output shaft, 451-Driving wheel, 4511-Cavity, 452-Driven wheel, 461-Drive ratchet, 462-Drive ratchet tooth, 463-First spring

[0074] 50 - Housing, 51 - Main body, 52 - Receiving part, 53 - Handle, 54 - Connecting part, 55 - Reinforcing part

[0075] 61-Support seat, 62-Rod shaft, 63-Guide seat, 64-Limit channel, 65-Guide channel, 66-Trigger,

[0076] 71-Locking block, 72-Second spring, 73-Cam, 74-Position switch, 75-Pin rod

[0077] 80 - Nail feeding device, 81 - Guide cover,

[0078] 90-Safety component, 91-Top rod, 92-Safety switch, 93-Third spring, 94-Contact piece, 95-Positioning bracket, 96-Elastic element. Detailed Implementation

[0079] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the terms "upper," "lower," "left," "right," "longitudinal," "lateral," "inner," "outer," "vertical," "horizontal," "top," and "bottom," etc., which indicate orientation or positional relationships, are based solely on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device / component referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0080] Example 1

[0081] Combination Figures 1 to 17 The fastener driving tool 100 provided in Embodiment 1 of the present invention includes:

[0082] Gas chamber 10, which is filled with pressurized gas;

[0083] The piston 21, which can move up and down, can be driven to move downward by the compressed gas in the air chamber 10.

[0084] The striking element 22, whose upper end is connected to the piston 21, moves downward with the piston 21 and drives the fastener 31 to be struck into the workpiece 32.

[0085] Lifting device 40 is used to drive piston 21 and striking element 22 to move upward;

[0086] The fastener driving tool 100 also includes a support cylinder 23 and a movable cylinder 24, wherein,

[0087] The support cylinder 23 is fixedly installed and extends in the vertical direction.

[0088] The movable cylinder 24 is located on the inner circumference of the support cylinder 23 and can move up and down. The movable cylinder 24 and the support cylinder 23 maintain a circumferential sealing fit. The piston 21 is located inside the movable cylinder 24 and can move up and down.

[0089] The air chamber 10 includes a first air chamber 10A and a second air chamber 10B that are not interconnected, wherein,

[0090] The first air chamber 10A is located outside the movable cylinder 24. The compressed gas in the first air chamber 10A can drive the movable cylinder 24 to move downward relative to the support cylinder 23. The upward-moving piston 21 can drive the movable cylinder 24 to move upward relative to the support cylinder 23. The upward-moving movable cylinder 24 compresses the gas in the first air chamber 10A.

[0091] The second air chamber 10B is formed by the cooperation of the movable cylinder 24 and the piston 21. The gas compressed in the second air chamber 10B can drive the piston 21 to move downward relative to the movable cylinder 24, and the upward moving piston 21 can compress the gas in the second air chamber 10B.

[0092] During nailing, the high-pressure gas in the first air chamber 10A drives the movable cylinder 24 to move downward relative to the support cylinder 23, while the high-pressure gas in the second air chamber 10B drives the striking element 22 to move downward relative to the movable cylinder 24. The high-pressure gas in both chambers allows the piston 21 to accelerate twice during nailing, increasing the movement speed of the striking element 22 and thus improving the nailing effect. Due to the dual-chamber structure, the impact vibration generated when the striking element 22 contacts the fastener 31 can be buffered twice by the gas in the two chambers, significantly reducing the vibration while meeting nailing requirements and improving the user experience.

[0093] In this embodiment, the fastener driving tool 100 further includes a housing 50. The housing 50 preferably has a split-shell structure. The housing 50 comprises a main body 51, a receiving portion 52, and a handle 53. The main body 51 extends generally in the vertical direction. The receiving portion 52 extends rearward from the lower part of the main body 51 and is used to house some components of the lifting device 40. The handle 53 extends rearward from the upper part of the main body 51 and is used for user gripping. There is a certain gap between the handle 53 and the receiving portion 52 in the vertical direction. The fastener driving tool 100 in this embodiment is preferably powered by a battery pack. The battery pack is preferably detachably mounted. A connecting portion 54 for receiving the battery pack is formed at the rear end of the handle 53.

[0094] The fastener insertion tool 100 also includes a base 25, an outer cylinder 261, and a cylinder head 27. The base 25 is fixed inside the main body 51. The upper and lower ends of the support cylinder 23 are open. The lower end of the support cylinder 23 is fixed to the base 25 and maintains a sealed fit with the base 25. The outer cylinder 261 is sleeved on the outer periphery of the support cylinder 23. The lower end of the outer cylinder 261 is fixed to the base 25 and maintains a sealed fit with the base 25. The cylinder head 27 is fixed to the upper end of the outer cylinder 261 and maintains a sealed fit with the outer cylinder 261. The movable cylinder 24 includes a side wall 241 and a top wall 242 located at the top of the side wall 241. An axially positioned sealing ring is sleeved on the outer periphery of the side wall 241, and the sealing ring maintains a circumferential sealed fit between the side wall 241 and the support cylinder 23. There is a certain height gap between the bottom surface of the cylinder head 27 and the top surface of the support cylinder 23. The space enclosed by the outer cylinder body 261, the support cylinder 23, the base 25, the cylinder head 27, and the top wall 242 of the movable cylinder body 24 is the first gas chamber 10A. A portion of the first gas chamber 10A is located above the top wall 242 of the movable cylinder body 24, allowing the high-pressure gas in the first gas chamber 10A to act smoothly on the movable cylinder body 24. The movable cylinder body 24 is closed at the top and open at the bottom. An axially positioned sealing ring is also fitted around the outer periphery of the piston 21, ensuring a circumferentially sealed fit between the piston 21 and the movable cylinder body 24. The space enclosed by the movable cylinder body 24 and the piston 21 is the second gas chamber 10B. Both the first gas chamber 10A and the second gas chamber 10B are pre-filled with high-pressure gas. The gas pressure in the two chambers can be approximately the same or slightly different. To regulate air pressure, two inflation valves can be installed to inflate the two chambers separately, or two exhaust valves can be installed to exhaust the air from the two chambers separately. Alternatively, a one-way valve can be installed on the top wall 242 of the movable cylinder 24 to balance the air pressure in the two chambers and prevent the air pressure difference between the two chambers from being too large.

[0095] The lower end of the support cylinder 23 is provided with a shock-absorbing block 28 located on the inner circumference of the base 25. The shock-absorbing block 28 is made of elastic materials such as rubber. The shock-absorbing block 28 can limit the extreme positions of the movable cylinder 24 and piston 21 when they move downward, preventing the movable cylinder 24 from detaching from the support cylinder 23 and also preventing the piston 21 from detaching from the movable cylinder 24. The center of the shock-absorbing block 28 is provided with a central hole 281 through which the striking element 22 passes.

[0096] In this embodiment, the upper end of the striking element 22 is connected to the piston 21 via a threaded connection or a pin hole connection. The piston 21, the striking element 22, and the movable cylinder 24 have an upper ready position and a lower end position. Normally, the piston 21, the striking element 22, and the movable cylinder 24 are in the ready position. At this time, the movable cylinder 24 is completely located inside the support cylinder 23, meaning the top wall 242 of the movable cylinder 24 is lower than or flush with the upper end of the support cylinder 23. The gas in the first air chamber 10A and the second air chamber 10B is under high pressure. During nail driving, the piston 21, the striking element 22, and the movable cylinder 24 move from the ready position to the end position. The higher-pressure gas in the first air chamber 10A drives the movable cylinder 24 to move the piston 21 downwards, and the higher-pressure gas in the second air chamber 10B drives the piston 21 to move downwards relative to the movable cylinder 24. When both the movable cylinder 24 and the piston 21 are in contact with the damping block 28, the piston 21, the striking element 22, and the movable cylinder 24 move downwards to the final position. At this time, the gas in the first air chamber 10A and the second air chamber 10B are both in a low-pressure state. The piston 21, moving upwards from the final position towards the ready position, compresses the gas in the second air chamber 10B. Simultaneously, the upward-moving piston 21 can drive the movable cylinder 24 to move upwards, and the upward-moving movable cylinder 24 compresses the gas in the first air chamber 10A. It can be understood that the piston 21 in the final position can also be above the damping block 28 without contacting it.

[0097] In this embodiment, the striking member 22 is provided with a plurality of protruding teeth 221 spaced apart along the vertical direction. The lifting device 40 includes a motor 43, a reduction gearbox 44, and a lifting gear 41. The lifting gear 41 can engage with the protruding teeth 221 on the striking member 22 to drive the striking member 22 to move upward toward the ready position. The upward movement of the striking member 22 simultaneously drives the piston 21 and the movable cylinder 24 to move upward toward the ready position. Specifically, the motor 43 and the reduction gearbox 44 are located in the receiving portion 52 of the housing 50. A support base 61 is fixed below the base 25. The lifting gear 41 is sleeved on the transmission shaft 42. The transmission shaft 42 is rotatably mounted on the support base 61 through bearings. The axial direction of the lifting device 40 is approximately perpendicular to the length direction of the striking member 22. A drive wheel 451 is sleeved on the output shaft 441 of the reduction gearbox 44, and a driven wheel 452 is sleeved on the rear end of the transmission shaft 42. A disengageable transmission structure is provided between the drive wheel 451 and the driven wheel 452. When the transmission structure is engaged, the motor 43 drives the drive wheel 451 to rotate through the reduction gearbox 44. The rotating drive wheel 451 drives the transmission shaft 42 to rotate around its own central axis through the transmission structure. The rotating transmission shaft 42 drives the lifting gear 41 to rotate synchronously in the direction shown in +ω. The lifting gear 41 rotating in the +ω direction drives the striking element 22 to move upward toward the ready position through meshing with the convex tooth 221. The upward moving striking element 22 drives the piston 21 and the movable cylinder 24 to also move toward the ready position.

[0098] Specifically, the driving wheel 451 has a cavity 4511 on the side facing the driven wheel 452, and the driven wheel 452 is located inside the cavity 4511. The transmission structure includes a transmission ratchet groove 461 on the cavity wall of the cavity 4511, a transmission ratchet 462 that can swing on the driven wheel 452, and a first spring 463 that biases the transmission ratchet 462 toward the cavity wall of the cavity 4511. The support base 61 is provided with a rod shaft 62 for pushing the transmission ratchet 462 away from the transmission ratchet groove 461. When the transmission ratchet 462 is engaged in the transmission ratchet groove 461 under the biasing action of the first spring 463, the transmission structure is in the engaged state. The driving wheel 451, driven by the motor 43, drives the transmission shaft 42 and the lifting gear 41 to rotate in the +ω direction through the engagement of the transmission ratchet groove 461 and the transmission ratchet 462, so that the lifting gear 41 can drive the striking member 22, the piston 21 and the movable cylinder 24 to move upward to the ready position. When the transmission ratchet 462 disengages from the transmission ratchet groove 461 under the resistance of the rod shaft 62, overcoming the bias of the first spring 463, the transmission structure is in a separated state. During nailing, the downward-moving striking element 22 drives the lifting gear 41 to rotate in the direction indicated by -ω. The lifting gear 41 rotating in the -ω direction drives the transmission shaft 42 and the driven wheel 452 to rotate freely relative to the driving wheel 451, preventing reverse rotation from being transmitted to the reduction gearbox 44. When it is necessary to drive the striking element 22 back to the ready position, the rotating driving wheel 451 can cause the transmission ratchet 462 to re-engage in the transmission ratchet groove 461.

[0099] To lock the striking element 22, piston 21, and movable cylinder 24 in the ready position under normal conditions, a sliding locking block 71 is provided on the support base 61. The sliding direction of the locking block 71 is substantially perpendicular to the movement direction of the striking element 22. Specifically, the locking block 71 is slidably mounted on the support base 61. The lower end of the striking element 22 has a groove 222 that mates with the locking block 71. The support base 61 also has a second spring 72 that biases the locking block 71 toward the groove 222. A cam 73 for unlocking the locking block 71 is sleeved on the drive shaft 42. The cam 73 can be integrally formed with the lifting gear 41, or it can be formed independently relative to the lifting gear 41. Under normal conditions, the partial embedment of the locking block 71 into the groove 222 holds the striking element 22, piston 21, and movable cylinder 24 in the ready position. During nailing, the motor 43 first causes the lifting gear 41, drive shaft 42, and cam 73 to rotate in the +ω direction. The cam 73, rotating in the +ω direction, drives the locking block 71 to slide away from the groove 222 against the bias of the second spring 72, thereby releasing the striking member 22. Almost simultaneously, the transmission structure switches from the engaged state to the disengaged state. The released striking member 22 moves rapidly downward under the drive of the piston 21. The downward movement of the striking member 22 causes the lifting gear 41, drive shaft 42, and driven wheel 452 to rotate in the opposite direction to the driving wheel 451. When the lifting gear 41 drives the striking member 22 upward to the ready position, the locking block 71 corresponds to the groove 222. Under the bias of the second spring 72, the locking block 71 slides towards the groove 222 and embeds into the groove 222, thereby locking the striking member 22 in the ready position.

[0100] To ensure timely shutdown of motor 43, a fixed stop switch 74 is provided on support base 61, and a pin 75 for triggering stop switch 74 is provided on locking block 71. A main control board is housed inside housing 50, and the stop switch 74 is connected to the main control board, which controls motor 43. Pin 75 releases stop switch 74 when locking block 71 disengages from groove 222, and triggers stop switch 74 when locking block 71 re-enters groove 222. The main control board can command motor 43 to stop based on the trigger signal from stop switch 74.

[0101] In this embodiment, a guide seat 63 is fixed to the front side of the support seat 61, and a limiting channel 64 for the impacting member 22 to move up and down is formed between the guide seat 63 and the support seat 61. The fastener driving tool 100 also includes a nail feeding device 80 detachably attached to the guide seat 63, and a guide cover 81 is provided at the front end of the nail feeding device 80. When the nail feeding device 80 is attached to the guide seat 63, the guide seat 63 and the guide cover 81 cooperate to form a guide channel 65 with openings at both the top and bottom. The nail feeding device 80 outputs the fastener 31 to be driven into the guide channel 65, and the downward-moving impacting member 22 enters the guide channel 65 and drives the fastener 31 to be driven into the workpiece 32. The impacting member 22, which moves upward to the ready position, disengages upward from the guide channel 65, so that the nail feeding device 80 can smoothly output the next fastener 31 to be driven into the guide channel 65. In this embodiment, the fastener 31 driven into the workpiece 32 can be a straight nail, a U-shaped nail, or other reasonable type.

[0102] A main switch is located inside the front end of the handle 53. The main switch signal is connected to the main control board. A trigger 66 for triggering the main switch is located on the bottom side of the front end of the handle 53. The housing 50 also has a reinforcing part 55 located between the receiving part 52 and the battery connection part 54. The main control board can be installed inside the reinforcing part 55.

[0103] The fastener driving tool 100 also includes a safety component 90. Specifically, the safety component 90 includes a push rod 91, a safety switch 92, a third spring 93, a positioning frame 95, and an elastic element 96. The push rod 91 is movable up and down and is located on the front side of the guide seat 63, and the travel of the push rod 91 is limited. The upper end of the push rod 91 extends into the main body 51 and is provided with a contact piece 94 for triggering the safety switch 92. The safety switch 92 can be fixed on the support seat 61 or the guide seat 63. The safety switch 92 is connected to the main control board. The third spring 93 biases the push rod 91 downward, causing the contact piece 94 to release the safety switch 92 in the normal state. The positioning frame 95 is fixed to the lower end of the push rod 91. The elastic element 96 is sleeved on the outside of the positioning frame 95 or located at the bottom of the positioning frame 95. When driving the fastener, the positioning frame 95 is pressed against the workpiece 32. The positioning frame 95 drives the push rod 91 to move upward against the bias of the third spring 93, causing the contact piece 94 to trigger the safety switch 92. The tool can only start the nailing program when both safety switch 92 and the main switch are triggered; there is no restriction on the triggering order of safety switch 92 and the main switch. For easy adjustment of the nailing depth, the positioning bracket 95 is preferably connected to the lower end of the push rod 91 via a threaded connection.

[0104] After the nailing procedure is initiated, the rotating cam 73 drives the latch 71 to disengage from the groove 222, thereby releasing the striking element 22. The high-pressure gas in the first air chamber 10A acts on the movable cylinder 24, causing it to move downwards relative to the support cylinder 23. This downward movement of the movable cylinder 24 drives the piston 21 and the striking element 22 downwards. Simultaneously, the high-pressure gas in the second air chamber 10B acts on the piston 21, causing it to move downwards relative to the movable cylinder 24. This downward movement of the piston 21 drives the striking element 22 downwards. The downward-moving striking element 22 extends into the guide channel 65, driving the fastener 31 to be struck into the workpiece 32. The lifting gear 41 rotates in the direction indicated by -ω during the downward movement of the striking element 22.

[0105] After the movable cylinder 24, piston 21, and striking element 22 reach their final positions, the lifting gear 41, driven by the motor 43, rotates in the direction indicated by +ω. The rotating lifting gear 41 drives the striking element 22 and piston 21 upwards. The upward-moving piston 21 compresses the gas in the second air chamber 10B and drives the movable cylinder 24 upwards, which in turn compresses the gas in the first air chamber 10A. When the striking element 22 reaches the ready position, the motor 43 stops.

[0106] As an alternative to this embodiment, a magnetic induction switch can be used instead of the position switch 74 to control the movement stroke of the striking element 22. Specifically, a magnet is provided on the striking element 22, and two vertically distributed magnetic induction elements are provided on the support 61 and / or guide 63. The magnetic induction elements are connected to the main control board, which determines the position of the striking element 22 based on the triggering of the magnetic induction elements. The magnetic induction elements can be Hall effect sensors or reed switches, etc. When the striking element 22 moves to the point where the magnet triggers one of the magnetic induction elements, it indicates that the striking element 22 has moved to the ready position. When the striking element 22 moves to the point where the magnet triggers the other magnetic induction element, it indicates that the striking element 22 has moved to the end position. Of course, the magnet can also be provided on the lifting gear 41.

[0107] As an alternative to this embodiment, the transmission structure of the lifting device 40 can also adopt an axial clutch structure. In this case, the driven wheel 452 or the driving wheel 451 can slide axially. During nailing, the driving wheel 451 and the driven wheel 452 are in a separated state, so that the driven wheel 452 can rotate freely relative to the driving wheel 451. After nailing is completed, the driving wheel 451 and the driven wheel 452 return to the engaged state under the bias of the spring.

[0108] As an alternative to this embodiment, a connecting rod can be provided between the striking member 22 and the piston 21. The upper end of the striking member 22 is connected to the connecting rod, and the upper end of the connecting rod is connected to the piston 21. The protruding teeth 221 that mesh with the lifting gear 41 are provided on the connecting rod. The lifting gear 41, which rotates in the +ω direction, drives the striking member 22 and the piston 21 to move upward toward the ready position through the connecting rod.

[0109] Combination Figure 18 As an alternative to this embodiment, the outer cylinder 261 can be configured as a non-cylindrical irregular structure. In this case, the outer cylinder 261 is located outside a portion of the support cylinder 23, and there is no fixed relationship between the outer cylinder 261 and the base 25. The outer cylinder 261 and the support cylinder 23 can be integrally formed, or they can be formed separately and then fixed together. Of course, the outer cylinder 261 can also be configured with other reasonable structures.

[0110] As an alternative to this embodiment, the lifting gear 41 can be provided with a missing tooth portion, that is, the teeth on the lifting gear 41 are not continuously arranged circumferentially. During nailing, the missing tooth portion of the lifting gear 41 faces the striking member 22, using the missing tooth portion to avoid the protruding teeth 221 on the striking member 22, allowing the striking member 22 to move smoothly downwards and avoiding interference of the lifting gear 41 with the nailing action of the striking member 22. After nailing is completed, the lifting gear 41, which rotates in the +ω direction, re-meshes with the protruding teeth 221 to drive the striking member 22 upwards towards the ready position. In this solution, the lifting gear 41 with the missing tooth portion can be directly sleeved on the output shaft 441 of the reduction gearbox 44, eliminating the need for the transmission shaft 42; of course, the lifting gear 41 can still be sleeved on the transmission shaft 42, in which case a coupling is provided between the transmission shaft 42 and the output shaft 441.

[0111] As an alternative to this embodiment, the lifting device 40 can also adopt the driving component 400 described in the utility model patent with publication number CN221539660U. In this case, the striking member 22 of this embodiment is not provided with protruding teeth 221, and the rack that serves as the moving member 420 in CN221539660U can be moved up and down relative to the striking member 22 in this embodiment.

[0112] As an alternative to this embodiment, the latch 71 can also be configured to be tiltable.

[0113] As an alternative to this embodiment, the cam 73 can also be omitted. In this case, the actions of the latch 71 in releasing the striking member 22 and locking the striking member 22 are both driven by the electromagnetic solenoid, which is controlled by the main control board.

[0114] As an alternative to this embodiment, the piston 21, striking element 22, and movable cylinder 24 can also be in the end position under normal conditions. When the nailing cycle is started, the lifting gear 41 first causes the striking element 22, piston 21, and movable cylinder 24 to move upward to the ready position. Then the transmission structure switches to the disengaged state, and the high-pressure gas in the two chambers drives the piston 21 and striking element 22 downward to the end position. At this time, the locking latch 71, second spring 72, cam 73, position switch 74, and pin 75 can be omitted.

[0115] As a further embodiment, the tool has a single-shot mode and a continuous-shot mode. The housing 50 has an operable mode selector. Users can switch the tool's nail-driving mode using the mode selector. The mode selector can be set to a reasonable style such as a bidirectional sliding push block, a tilting button, a rotatable knob, a button, or a touch screen.

[0116] As a further embodiment, in order to improve the stability of the nail feeding device 80, a quick-release connection structure can be provided between the rear end of the nail feeding device 80 and the receiving part 52 of the housing 50.

[0117] Example 2

[0118] Combination Figure 19 , Figure 20 In this embodiment, the axial height of the support cylinder 23 is shortened. When the movable cylinder 24 is in the ready position, most of the movable cylinder 24 extends upward beyond the support cylinder 23, while the lower end of the movable cylinder 24 remains inside the support cylinder 23. When the movable cylinder 24 is in the finished position, the top wall 242 of the movable cylinder 24 is substantially flush with the upper surface of the support cylinder 23, or the top wall 242 of the movable cylinder 24 is slightly higher than the upper surface of the support cylinder 23.

[0119] To ensure the nailing effect, the unidirectional stroke of the movable cylinder 24 is equal to or slightly greater than the length of the fastener to be driven.

[0120] To prevent the upward-moving movable cylinder 24 from detaching from the support cylinder 23, a ring of limiting ribs can be set at the upper end of the support cylinder 23 and the lower end of the movable cylinder 24, respectively. The movable cylinder 24 is axially limited by the two rings of limiting ribs.

[0121] Combination Figure 21To allow the movable cylinder 24 to move smoothly up and down relative to the support cylinder 23, a limiting part 291 can be provided above the support cylinder 23. The limiting part 291 radially limits the portion of the movable cylinder 24 extending out of the support cylinder 23. The movable cylinder 24, moving upwards towards the ready position, enters the limiting part 291 after extending out of the support cylinder 23. The limiting part 291 also provides a guiding function for the movable cylinder 24. At least two limiting parts 291 are spaced apart along the outer periphery of the movable cylinder 24. Between two adjacent limiting parts 291, there is a flow groove 292 for gas flow in the first air chamber 10A. The limiting part 291 is preferably arc-shaped in cross-section perpendicular to the axial direction, and its inner diameter is slightly larger than the outer diameter of the movable cylinder 24. The limiting part 291 can be integrally formed with the support cylinder 23, integrally formed with the cylinder head 27, or independently formed and then fixed to the top of the support cylinder 23, the bottom of the cylinder head 27, or the interior of the outer cylinder 261.

[0122] The other structures of Embodiment 2 are the same as those of Embodiment 1, and will not be described in detail here.

[0123] Example 3

[0124] Combination Figure 22 , Figure 23 In this embodiment, the first air chamber 10A is located entirely at the top of the movable cylinder 24. Specifically, the outer cylinder body of Embodiment 1 is omitted, the support cylinder 23 can be directly fixed to the support base, the cylinder head 27 is adapted to the support cylinder 23 and directly fixed to the top of the support cylinder 23, and the shock absorber 28 is fixed to the inner circumference of the lower end of the support cylinder 23. The movable cylinder 24 still has a side wall 241 and a top wall 24 located at the top of the side wall 241. The movable cylinder 24 is located inside the support cylinder 23 and the two maintain a circumferential sealed fit. The outer diameter of the support cylinder 23 is set uniformly from top to bottom, that is, the support cylinder 23 is a hollow straight cylinder. The space enclosed by the support cylinder 23, the cylinder head 27 and the top wall 242 of the movable cylinder 24 forms the first air chamber 10A, and the space enclosed by the movable cylinder 24 and the piston 21 forms the second air chamber 10B. The two air chambers are still not connected to each other, and pressurized gas can be pre-filled in the two air chambers. To regulate the air pressure in the two chambers, an inflation valve can be installed on the top wall 242 of the cylinder head 27 and the movable cylinder block 24. Alternatively, an exhaust valve can be installed to depressurize the first chamber 10A and the second chamber 10B. As a feasible solution in this embodiment, the support cylinder 23 and the cylinder head 27 can be integrally formed, or they can be separately formed and then fixed together.

[0125] Combination Figure 22 When the piston 21, the striking element 22 and the movable cylinder 24 are in the ready position, both the first air chamber 10A and the second air chamber 10B are under high pressure.

[0126] During nailing, the high-pressure gas in the first air chamber 10A drives the movable cylinder 24 to move downward relative to the support cylinder 23. The downward movement of the movable cylinder 24 simultaneously drives the piston 21 and the striking element 22 to move downward. At the same time, the high-pressure gas in the second air chamber 10B drives the piston 21 to move downward relative to the movable cylinder 24. The downward movement of the piston 21 drives the striking element 22 to move downward synchronously. The downward movement of the striking element 22 drives the fastener to be struck into the workpiece.

[0127] Combination Figure 23 When the movable cylinder 24, piston 21, and striking element 22 move downwards to the final position, the movable cylinder 24 and piston 21 both come into contact with the damping block 28. Of course, when the movable cylinder 24, piston 21, and striking element 22 move downwards to the final position, the piston 21 may also be higher than the damping block 28 and not come into contact with it.

[0128] When the lifting device drives the striking element 22 to move upward toward the ready position, the striking element 22 drives the piston 21 to move upward synchronously. The piston 21, which moves upward relative to the movable cylinder 24, squeezes the gas in the second air chamber 10B. At the same time, the piston 21 drives the movable cylinder 24 to move upward relative to the support cylinder 23. The upwardly moving movable cylinder 24 squeezes the gas in the first air chamber 10A.

[0129] Combination Figure 24 In another embodiment, the support cylinder 23 is wider at the top and narrower at the bottom, forming a stepped portion 231. Because the outer diameter of the upper part of the support cylinder 23 is larger, the volume of the first air chamber 10A can be effectively increased, thereby increasing the movement speed of the striking element 22 during nailing and improving the nailing effect. Furthermore, when the movable cylinder 24, piston 21, and striking element 22 are in the ready position, the movable cylinder 24 is not higher than the stepped portion 231; that is, the top wall 242 of the movable cylinder 24 is slightly lower than or flush with the stepped portion 231, so that the entire first air chamber 10A is always located at the top of the movable cylinder 24. The upper and lower parts of the support cylinder 23 can be integrally formed or separately formed and then fixed together. To limit the upward stroke of the movable cylinder 24, a rib can be provided on the inner wall of the lower part of the support cylinder 23 or at the stepped portion 231 to limit the movement of the movable cylinder 24. The movable cylinder 24 reaches the ready position when it moves upward and contacts the rib.

[0130] Combination Figure 25In another embodiment, to prevent the piston 21, which moves downward relative to the movable cylinder 24, from disengaging from the movable cylinder 24, a limiting cover 243 is provided at the lower end of the movable cylinder 24. The limiting cover 243 has an elastic block 244 on its top side facing the movable cylinder 24, located below the piston 21. Both the elastic block 244 and the limiting cover 243 have clearance holes 245 for the impacting element to pass through. When the piston 21 moves downward relative to the movable cylinder 24 to contact the elastic block 24, the piston 21 moves downward relative to the movable cylinder 24 to its extreme position. In this embodiment, the movable cylinder 24, moving downward to its final position, can cause the limiting cover 243 to contact the shock absorber 28, or it can be slightly higher than the shock absorber 28 without contacting it; the piston 21, moving downward to its final position, can contact the elastic block 244, or it can be slightly higher than the elastic block 244 without contacting it. The limit cover 243 can be connected to the lower end of the movable cylinder 24 by means of threaded engagement, screw engagement, etc. The elastic block 244 can be made of elastic material such as rubber, and the clearance hole 245 is clearance-fitted with the striking part 22.

[0131] The other structures of Embodiment 3 are the same as those of Embodiment 1, and will not be described again here.

[0132] Example 4

[0133] Combination Figure 26 , Figure 27 In this embodiment, the fastener driving tool includes:

[0134] Gas chamber 10', which is filled with pressurized gas;

[0135] The piston 21, which can move up and down, can be driven to move downward by the compressed gas in the air chamber 10.

[0136] The striking element 22, whose upper end is connected to the piston 21, moves downward with the piston 21 and drives the fastener to be struck into the workpiece.

[0137] A lifting device is used to drive the piston 21 and the striking element 22 upward;

[0138] The fastener driving tool also includes an inner cylinder 262, the upper end of which is provided with a through hole 263;

[0139] Piston 21 is located in inner cylinder 262, and piston 21 and striking element 22 have an upper ready position and a lower end position.

[0140] The air chamber 10' includes a first air chamber 10A' and a second air chamber 10B'. The first air chamber 10A' is located outside the inner cylinder 262, and the second air chamber 10B' is formed by the inner cylinder 262 and the piston 21.

[0141] The piston 21, moving from the ready position to the end position, can open the through hole 263 to connect the first air chamber 10A' with the second air chamber 10B';

[0142] The piston 21, moving from the end position to the ready position, can close the through hole 263 to isolate the first air chamber 10A' from the second air chamber 10B'.

[0143] During nailing, the high-pressure gas in the second air chamber 10B' firstly causes the piston 21 and the striking element 22 to move downwards. When the piston 21 moves downwards below the through hole 263, the through hole 263 is opened by the piston 21, and the first air chamber 10A' and the second air chamber 10B' become interconnected. The high-pressure gas in the first air chamber 10A' can flow into the second air chamber 10B' through the through hole 263 and act together on the piston 21, causing the piston 21 and the striking element 22 to move downwards. By utilizing two interconnected air chambers, the piston 21 can accelerate twice during nailing, which helps to increase the movement speed of the striking element 22, thereby improving the nailing effect. In addition, since there are two air chambers, the impact vibration generated when the striking element 22 contacts the fastener can be buffered twice by the gas in the two air chambers. This can greatly reduce the vibration caused by nailing while meeting the nailing requirements, which is beneficial to improving the user experience.

[0144] In one specific embodiment, the inner cylinder 262 includes a side cylinder wall 262a extending vertically and a top cylinder wall 262b located at the top of the side cylinder wall 262a. Regardless of whether the piston 21 is in the ready position or the finished position, there is a certain height difference between the piston 21 and the top cylinder wall 262b, and there is also a certain height difference between the through hole 263 and the top cylinder wall 262b. The space enclosed by the inner cylinder 262 and the piston 21 forms a second air chamber 10B', and the space enclosed by the inner cylinder 262, the outer cylinder 261, the cylinder head 27, and the base 25 constitutes a first air chamber 10A'. The volume of the first air chamber 10A' is always greater than the volume of the second air chamber 10B'.

[0145] The piston 21 is fitted with several vertically spaced and axially positioned sealing rings 211 on its outer periphery, which maintain a circumferential sealing fit between the piston 21 and the inner cylinder 262. When the piston 21 is in the ready position, the through hole 263 is located axially between two adjacent sealing rings 211. At this time, the through hole 263 is closed by the piston 21, and the first air chamber 10A' and the second air chamber 10B' are isolated from each other.

[0146] During the process of the lifting device driving the striking element 22 and piston 21 to move upward from the end position to the ready position, piston 21 compresses gas. Before piston 21 moves to the closed through hole 263, the gas in both air chambers is compressed and the gas pressure in the two air chambers is temporarily the same because the two air chambers are connected through the through hole 263. When piston 21 moves to the closed through hole 263, the two air chambers are separated, and piston 21 continues to move upward a short distance and continues to compress the gas in the second air chamber 10B'. When piston 21 and striking element 22 move to the ready position, piston 21 closes through hole 263, the second air chamber 10B' is temporarily not connected to the first air chamber 10A', and the gas pressure in the second air chamber 10B' is higher than the gas pressure in the first air chamber 10A'.

[0147] When the through hole 263 is opened by the piston 21, in order to increase the gas flow between the first air chamber 10A' and the second air chamber 10B', the through hole 263 is provided with multiple holes at intervals along the circumference of the inner cylinder 262.

[0148] Combination Figure 28 In another specific embodiment, the inner cylinder 262 has openings at both its upper and lower ends. The upper end of the inner cylinder 262 extends close to the cylinder head 27. A sealing gasket 264 is provided between the upper end face of the inner cylinder 262 and the lower surface of the cylinder head 27, thereby maintaining a sealed fit between the inner cylinder 262 and the cylinder head 27. In this case, the second air chamber 10B' is formed by the inner cylinder 262, the cylinder head 27, and the piston 21, while the first air chamber 10A' is still formed by the inner cylinder 262, the outer cylinder 261, the cylinder head 27, and the base 25.

[0149] The other structures in Embodiment 4 are the same as those in Embodiment 1, and will not be described in detail here.

[0150] In addition to the preferred embodiments described above, the present invention may have other embodiments. Those skilled in the art can make various changes and modifications based on the present invention, and all such changes and modifications should fall within the scope defined in the claims of the present invention, as long as they do not depart from the spirit of the present invention.

Claims

1. Fastener driving tools, including: The air chamber is filled with pressurized gas. A piston that can move up and down; the compressed gas in the chamber can drive the piston to move downward. The striking component, whose upper end is connected to the piston, moves downward with the piston to drive the fastener to be struck into the workpiece. A lifting device is used to drive the piston and striking component upwards; The fastener driving tool is characterized in that it further includes a support cylinder and a movable cylinder, wherein, The support cylinder is fixedly installed and extends in the vertical direction. The movable cylinder is located on the inner circumference of the support cylinder and can move up and down. The movable cylinder and the support cylinder maintain a circumferential sealed fit. The piston is located inside the movable cylinder and can move up and down. The air chambers include a first air chamber and a second air chamber that are not interconnected, wherein, The first air chamber is located outside the movable cylinder. The gas compressed in the first air chamber can drive the movable cylinder to move downward relative to the support cylinder. The piston moving upward can drive the movable cylinder to move upward relative to the support cylinder. The movable cylinder moving upward compresses the gas in the first air chamber. The second chamber is formed by the cooperation of the movable cylinder and the piston. The gas compressed in the second chamber can drive the piston to move downward relative to the movable cylinder, and the piston moving upward can compress the gas in the second chamber.

2. The fastener driving tool according to claim 1, characterized in that, The movable cylinder has side walls and a top wall located at the top of the side walls, with at least a portion of the first air chamber located above the top wall.

3. The fastener driving tool according to claim 1, characterized in that, The piston, striking element, and movable cylinder are in a ready position, with the movable cylinder in the ready position completely located inside the support cylinder.

4. The fastener driving tool according to claim 1, characterized in that, The piston, striking element, and movable cylinder are in a ready position, with at least a portion of the movable cylinder in the ready position protruding above the support cylinder.

5. The fastener driving tool according to claim 4, characterized in that, The upper part of the support cylinder is provided with a limiting part that is adapted to the movable cylinder body. The movable cylinder body, which moves to the ready position, can extend out of the support cylinder and enter the limiting part.

6. The fastener driving tool according to claim 4, characterized in that, The piston, striking element, and movable cylinder have an end position, with the upper end of the movable cylinder in the end position being higher than or flush with the upper end of the support cylinder.

7. The fastener driving tool according to claim 3 or 4, characterized in that, The piston, striking element, and movable cylinder have end positions, and the fastener driving tool also includes a shock-absorbing block fixed to the lower end of the support cylinder, with the lower end of the movable cylinder in the end position abutting against the shock-absorbing block.

8. The fastener driving tool according to claim 1, characterized in that, The movable cylinder has side walls and a top wall located at the top of the side walls, and the first air chamber is entirely located at the top of the movable cylinder.

9. The fastener driving tool according to claim 8, characterized in that, The upper end of the support cylinder is provided with a cylinder cover, and the first air chamber is formed by the support cylinder, the cylinder cover and the top wall of the movable cylinder.

10. The fastener driving tool according to claim 9, characterized in that, The outer diameter of the support cylinder is the same from top to bottom; or, the support cylinder is wider at the top and narrower at the bottom and has a stepped portion, and the movable cylinder body is always not higher than the stepped portion.

11. The fastener driving tool according to claim 8, characterized in that, The lower end of the movable cylinder is provided with a limiting cover. On the side of the limiting cover facing the movable cylinder, there is an elastic block located below the piston. Both the elastic block and the limiting cover are provided with clearance holes for the impacting component to pass through.

12. Fastener driving tools, including: The air chamber is filled with pressurized gas. A piston that can move up and down; the compressed gas in the chamber can drive the piston to move downward. The striking component, whose upper end is connected to the piston, moves downward with the piston to drive the fastener to be struck into the workpiece. A lifting device is used to drive the piston and striking component upwards; The fastener driving tool is characterized in that it further includes an inner cylinder, and the upper end of the inner cylinder is provided with a through hole; The piston is located in the inner cylinder, and the piston and the striking element have an upper ready position and a lower end position. The air chamber includes a first air chamber and a second air chamber. The first air chamber is located outside the inner cylinder, and the second air chamber is formed by the inner cylinder and the piston. The piston moving from the ready position to the end position can open the through hole to connect the first air chamber with the second air chamber; The piston moving from the end position to the ready position can close the through hole to isolate the first air chamber from the second air chamber.

13. The fastener driving tool according to claim 12, characterized in that, The through holes are provided at intervals along the circumference of the inner cylinder.

14. The fastener driving tool according to claim 12, characterized in that, The piston and the inner cylinder are provided with a sealing ring to maintain a circumferential sealing fit. At least two sealing rings are provided at intervals between the upper and lower parts, and the through hole is located between two adjacent sealing rings when the piston is in the ready position.

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