A pneumatic nail gun

Abstract

The present invention provides a pneumatic nail gun, which belongs to the technical field of electric tools. It solves the problem of existing pneumatic nail guns that the nailing force is difficult to adjust in order to make the unlocking of the power piston more stable and reliable. The pneumatic nail gun includes a shell, a booster cylinder and a power cylinder are provided in the shell, a booster piston is provided in the booster cylinder, a power piston that can be locked when the booster piston boosts the inner cavity is provided in the power cylinder, and when the booster piston completes the boosting stroke, the motor can release the lock on the power piston. A pressure relief channel is provided between the power piston and the power cylinder. The pneumatic nail gun also includes a speed control module that can control the motor speed. The speed control module adjusts the time required for the booster piston to complete the boosting stroke by controlling the motor speed. The speed control module can control the motor to output at least two different speeds. The pneumatic nail gun can control the nailing force by the motor speed.

Description

Technical Field

[0001] The invention belongs to the technical field of electric tools and relates to a pneumatic nail gun. Background Art

[0002] A pneumatic nail gun is composed of a gun body and a nail box. The gun body is composed of a gun casing, a cylinder, a trigger assembly, a firing pin assembly, a gun nozzle and a bumper assembly. The gas is compressed in the cylinder to form a pressure difference, and the trigger switch is used to make the firing pin move back and forth in the cylinder. Usually, a pneumatic nail gun relies on the air pressure in the power cylinder to push the power piston and then drive the nails out. Therefore, the air pressure in the power cylinder determines the force with which the nails are driven out.

[0003] In order to ensure the accuracy of the air pressure value, and thus ensure the accuracy of the force of driving out steel nails, the patent document (application number: 201920866981.6) discloses a multifunctional air nozzle and a convenient pneumatic nail gun. The air nozzle is a three-way valve, one end of which is connected to the inner cavity of the power cylinder body, one end is connected to the air source, and one end is connected to the outside and is installed with a valve core. When the air source inflates the air pressure in the power cylinder body to the set value, the valve core can be pushed open, and the excess gas is discharged from the valve core, thereby ensuring the accuracy of the air pressure value in the power cylinder body. However, since the air pressure value required to open the valve core is certain, this air pressure value determines the air pressure value in the power cylinder body, and thus determines the force of driving out the steel nails, making the force difficult to adjust.

[0004] In response to the above problems, in order to be able to adjust the force of driving steel nails, the patent document (application number: 201810197044.6) discloses a mosquito nail gun with adjustable nailing force. The principle is that a strong magnet is provided at the rear end of the power cylinder body, and the strong magnet adsorbs the nailing piston. When the air pressure in the power cylinder body reaches the adsorption force of the strong magnet, the nailing piston is separated from the strong magnet and driven out. The position of the adjusting screw can be adjusted by the knob at the rear end to adjust the attraction position, and then adjust the adsorption force between the two, that is, adjust the air pressure value required for the nailing piston to separate from the strong magnet, and then adjust the nailing force. However, this is based on adjusting the locking force of the nailing piston during the pressurization process to adjust the final nailing force. Directly adjusting the locking force of the nailing piston will affect the stability and safety of driving the steel nails. If the locking force is too large, it will affect the stability of driving the steel nails. If the locking force is too small, it will affect the safety of driving the steel nails. Summary of the Invention

[0005] The purpose of the present invention is to address the above-mentioned problems in the existing technology and propose a pneumatic nail gun to solve the problem that the nailing force of the existing pneumatic nail gun is difficult to adjust in order to make the power piston unlocking more stable and reliable.

[0006] The objectives of the present invention can be achieved through the following technical solutions: A pneumatic nail gun, comprising a shell, a booster cylinder and a power cylinder with interconnected inner cavities provided in the shell, a booster piston driven by a motor to pressurize the inner cavity of the power cylinder provided in the booster cylinder, a power piston that can be locked when the booster piston pressurizes the inner cavity provided in the power cylinder, characterized in that when the booster piston completes the boosting stroke, the motor can release the lock on the power piston, a pressure relief channel is provided between the power piston and the power cylinder, the pneumatic nail gun also includes a speed control module that can control the motor speed, the speed control module adjusts the time required for the booster piston to complete the boosting stroke by controlling the motor speed, and the speed control module can control the motor to output at least two different speeds.

[0007] The motor drives the booster piston to move and compress the gas in the booster cylinder. The inner cavity of the booster cylinder is connected to the inner cavity of the power cylinder, and the power piston is locked. Therefore, the gas pressure in the power cylinder rises, that is, the output shaft driven by the motor rotates half a circle to drive the booster piston to complete a boost stroke. At the same time that the booster piston completes the boost stroke, the motor can unlock the power piston, and the power piston is pushed out to achieve nailing. The boosting process of the booster piston and the unlocking process of the power piston are both controlled by the same motor, thereby ensuring the synchronous stability and reliability of the two. The output shaft driven by the motor rotates for the next half circle to drive the booster piston to reset and move, and the power piston is adsorbed and reset. Since the strokes of the booster piston and the power piston are fixed, the amount of gas between the two is fixed, and the air pressure generated after the compression of the fixed stroke of the booster piston is also fixed. For this reason, the present application adjusts the force of the power piston when it is pushed out by adjusting the air pressure value generated after the booster piston compresses the gas. Specifically, it is different from the conventional idea of setting a piston ring between the piston and the cylinder to improve the sealing. In the present application, a pressure relief channel is provided between the power piston and the power cylinder body, that is, when the power piston is locked and the booster piston is moving during the boosting process, the gas in the power piston can partially leak to the outside of the power piston through the pressure relief channel, thereby causing the air pressure value generated when the booster piston completes the boosting stroke to drop, thereby reducing the force of the power piston being pushed out after being unlocked by the motor. The nail gun is also provided with a speed control module, so that the motor speed can be controlled and has at least two different speeds. When the motor is in a lower speed gear, the time required for the booster piston to complete the boosting stroke is longer, the time for the pressure relief channel to relieve pressure is also longer, the air pressure in the power cylinder body is smaller, and the force exerted by the power piston is also smaller. When the motor is in a higher speed gear, the time required for the booster piston to complete the boosting stroke is shorter, the time for the pressure relief channel to relieve pressure is also shorter, the air pressure in the power cylinder body is larger, and the force exerted by the power piston is also larger. That is, the motor speed is controlled by the speed control module, and the nailing force is controlled by the motor speed, so that there are at least two different nailing forces.

[0008] In the aforementioned pneumatic nail gun, one end of the pressure relief passage communicates with the inner cavity of the power piston and the other end communicates with the outer side of the power piston. The outer diameter of the power piston is smaller than the inner diameter of the inner cavity of the power cylinder. The pressure relief passage comprises a gap formed between the outer peripheral wall of the power piston and the inner peripheral wall of the power cylinder. The power piston is provided with a guide member that slidably engages with the inner peripheral wall of the power cylinder and provides guidance for the sliding of the power piston. Unlike the conventional concept of requiring a seal between the piston and the cylinder, the present application explicitly states that the outer diameter of the power piston is smaller than the inner diameter of the cylinder, intentionally creating a gap between the two for pressure relief, allowing gas in the inner cavity of the power piston to partially leak out of the power piston through the pressure relief passage. This structure eliminates the need for axial grooves, axial holes, or other structural disruptions to the power piston, thereby ensuring the structural stability of the power piston. The influence of the gap between the power piston and the cylinder on the stability of the power piston's movement is addressed by providing a guide member. The guide member ensures that there is always a gap between the outer peripheral wall of the power piston and the inner peripheral wall of the cylinder for pressure relief, while also ensuring the stability of the power piston's movement.

[0009] In the aforementioned pneumatic nail gun, an annular pressure relief groove is circumferentially formed on the outer circumferential wall of the power piston, and the guide member includes a guide ring sleeved within the pressure relief groove, the outer circumferential wall of the guide ring slidably engaging with the inner circumferential wall of the power cylinder body. The guide ring slidably engages with the inner circumferential wall of the power cylinder body to support and guide the power piston. Gas leaking from the gap between the outer circumferential wall of the power piston and the inner circumferential wall of the power cylinder body can pass through the pressure relief groove, ensuring smooth pressure relief. Of course, if the sole purpose is to provide support and guidance for the power piston, the guide member can also be a plurality of protrusions on the outer wall of the power piston, with the protrusions abutting against the inner circumferential wall of the power cylinder body, while the gaps between adjacent protrusions allow gas to pass through.

[0010] In the aforementioned pneumatic nail gun, the width of the pressure relief groove is greater than the width of the guide ring, the diameter of the bottom surface of the pressure relief groove is smaller than the inner diameter of the guide ring, and the pressure relief channel also includes gaps formed between the side walls of the guide ring and the two groove walls of the pressure relief groove, and a gap formed between the inner peripheral wall of the guide ring and the bottom surface of the pressure relief groove. During the reciprocating movement of the power piston, the side walls of the guide ring may abut against one side wall of the pressure relief groove. However, under the action of relatively high air pressure, gas is sufficient to pass between the gaps to achieve pressure relief.

[0011] In the aforementioned pneumatic nail gun, the guide ring is made of polytetrafluoroethylene (PTFE) and has a fracture formed therein. A tensioning member is also provided within the pressure relief groove, enabling the guide ring to radially expand and deform and compress against the inner circumferential wall of the power cylinder. PTFE is heat-resistant, highly ductile, and structurally stable, and has a low coefficient of friction, allowing the guide ring to maintain its stability while sliding smoothly with the power cylinder. The guide ring, being deformable and elastic, is provided with a fracture. This fracture allows the guide ring to overcome its inherent toughness constraints, allowing it to radially expand and deform, thereby fully abutting against the inner circumferential wall of the power cylinder under the action of the tensioning member. This maintains a gap between the inner circumferential wall of the guide ring and the bottom surface of the pressure relief groove for pressure relief. The fracture can also be used directly to relieve gas pressure, allowing the guide ring to support and guide the power piston while also providing a gas pressure relief function.

[0012] In the aforementioned pneumatic nail gun, the tensioning member comprises a rubber ring. An annular limiting groove is circumferentially defined on the bottom surface of the pressure relief groove, the limiting groove having a width smaller than that of the pressure relief groove. The rubber ring is positioned within the limiting groove, and the outer edge of the rubber ring is tensioned against the inner circumference of the guide ring. Under the elastic force of the rubber ring, the outer circumferential wall of the guide ring presses against the inner circumferential wall of the power cylinder. The rubber ring has a high elasticity. When its outer diameter in its natural state is larger than the inner diameter of the guide ring in its natural state, and the rubber ring is positioned inside the guide ring, the rubber ring can exert a radially outward expansion force on the guide ring, thereby ensuring that the guide ring fully abuts against the inner circumferential wall of the power cylinder. Of course, in actual processing, the rubber ring can also be a flexible metal ring, which can also be provided with a fracture to exert an outward expansion force.

[0013] In the aforementioned pneumatic nail gun, the stop groove is located in the middle of the pressure relief groove in the width direction. The rubber ring is narrower than the stop groove, and its inner diameter is larger than the bottom diameter of the stop groove. The narrow rubber ring forms a gap with the bottom surface of the stop groove, allowing gas to pass through the gap between the guide ring and the wall of the pressure relief groove, as well as the gap between the rubber ring and the wall of the stop groove, ensuring smooth pressure relief.

[0014] In the aforementioned pneumatic nail gun, both ends of the outer peripheral wall of the guide ring are chamfered to form guide conical surfaces. The distance from the annular edge where the guide conical surface connects to the end face of the guide ring to the inner peripheral wall of the power cylinder body is greater than the gap between the outer peripheral wall of the power piston and the inner peripheral wall of the power cylinder body. The gap between the power piston and the power cylinder body is opposite to the guide conical surfaces, and the edge where the guide conical surface connects to the end face of the power piston has a small diameter. This allows gas to act on the guide conical surfaces, allowing the gas to enter the gap between the guide ring and the wall of the pressure relief groove under the action of the guide conical surfaces, thereby ensuring smooth gas flow.

[0015] In the aforementioned pneumatic nail gun, the gap between the outer peripheral wall of the power piston and the inner peripheral wall of the power cylinder is wider than the sum of the gaps between the side walls of the guide ring and the walls of the pressure relief groove. By providing guide rings of varying widths, the pressure relief speed can be adjusted, thereby adjusting the nailing force.

[0016] In the aforementioned pneumatic nail gun, a long, strip-shaped striker is fixedly attached to the outer end surface of the power cylinder, a positioning notch is defined on one side edge of the striker, a disc-shaped positioning block is rotatably connected to the housing, the positioning block having a clearance surface on its outer circumferential surface, and a positioning torsion spring is disposed between the housing and the positioning block. When the motor drives the booster piston to perform a boost stroke, the positioning block is engaged in the positioning notch under the action of the positioning torsion spring, thereby locking the power piston. When the booster piston completes the boost stroke, the motor drives the positioning block to rotate, causing the clearance surface on the positioning block to face the positioning notch. In other words, the motor drives the booster piston to perform boosting, and after the boost stroke is completed, the motor also drives the positioning block to rotate, thereby unlocking the power piston, thereby ensuring the stability and reliability of the power piston.

[0017] Compared with the existing technology, this pneumatic nail gun has the following advantages:

[0018] 1. Since a pressure relief channel is provided between the power piston and the power cylinder body, when the power piston is locked and the booster piston is moving during the boosting, the gas in the inner cavity inside the power piston can partially leak to the outside of the power piston through the pressure relief channel, thereby causing the air pressure value generated when the booster piston completes the boosting stroke to drop, thereby reducing the force with which the power piston is pushed out after being unlocked by the motor. That is, when the motor speed is slower, the boosting time is longer, the pressure relief time of the pressure relief channel is longer, the air pressure in the power cylinder body is smaller, and the force exerted by the power piston is smaller. When the motor speed is faster, the boosting time is shorter, the pressure relief time of the pressure relief channel is shorter, the air pressure in the power cylinder body is greater, and the force exerted by the power piston is greater, thereby adjusting the nailing force by controlling the motor speed.

[0019] 2. Since a fracture is provided on the guide ring, the fracture can enable the guide ring to break through the constraints of its own toughness, so that the guide ring can expand and deform in the radial direction, so that it can fully rest against the inner peripheral wall of the power cylinder under the action of the tensioner, thereby maintaining a gap between the inner peripheral wall of the guide ring and the bottom surface of the pressure relief groove for pressure relief. Of course, the fracture can also be directly used for gas to pass through and relieve pressure, so that the guide ring has the pressure relief function of gas passing through while supporting and guiding the power piston. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural sectional view of a pneumatic nail gun.

[0021] Figure 2It is a partial structural cross-sectional view of the boost cylinder and power cylinder.

[0022] Figure 3 yes Figure 2 A magnified view of the structure at point A in the middle.

[0023] Figure 4 It is a schematic diagram of the three-dimensional structure of the power piston.

[0024] Figure 5 yes Figure 1 A magnified view of the structure at point B.

[0025] Figure 6 It is a structural cross-sectional view of a pneumatic nail gun at the power cylinder.

[0026] Figure 7 yes Figure 6 Enlarged view of the structure at point C in the middle.

[0027] Figure 8 It is a schematic diagram of the partial three-dimensional structure of the pneumatic nail gun behind the hidden shell.

[0028] Figure 9 It is a schematic diagram of the partial three-dimensional structure of the pneumatic nail gun from another perspective after the shell is hidden.

[0029] In the figure, 1, housing; 11, positioning bolt; 2, booster cylinder; 3, power cylinder; 4, booster piston; 41, connecting rod; 5, power piston; 51, pressure relief groove; 52, limit groove; 53, guide ring; 531, fracture; 532, guide cone; 54, rubber ring; 55, columnar body; 551, connecting groove; 552, rivet hole; 553, rivet; 56, striker; 561, connecting hole; 562, positioning notch ;6. Pressure relief channel;7. Motor;71. Speed ​​variator;72. Output shaft;73. Drive arm;731. Push pin;8. Positioning block;81. Positioning convex portion;82. Yield plane;83. Positioning torsion spring;84. Locking convex portion;85. Connecting column;9. Rotating column;91. Locking block;911. Locking arm;92. Locking torsion spring;93. Unlocking swing arm;94. Connecting arm;95. Transmission swing arm;951. Transmission push plate. DETAILED DESCRIPTION

[0030] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0031] like Figure 1 、 Figure 2As shown, a pneumatic nail gun includes a shell 1, in which a booster cylinder 2 and a power cylinder 3 are fixed. The power cylinder 3 and the booster cylinder 2 are arranged along the front and back, and the power cylinder 3 is located above the booster cylinder 2. The inner cavity of the power cylinder 3 is connected with the inner cavity of the booster cylinder 2. A booster piston 4 is provided in the booster cylinder 2, and a power piston 5 is provided in the power cylinder 3. Since the inner diameter of the power cylinder 3 is smaller than the inner diameter of the booster cylinder 2, and the length of the power cylinder 3 is greater than the length of the booster cylinder 2, the nailing stroke when the power piston 5 is pushed out is greater than the moving stroke of the booster piston 4 when boosting. A motor 7 is also provided in the shell 1. The motor 7 is arranged vertically, and a speed changer 71 is provided above the motor 7. The motor 7 shaft of the motor 7 is connected to the speed changer 71. The speed changer 71 outputs power through a vertically arranged output shaft 72, that is, the output shaft 72 is connected to the booster piston 4. When the output shaft 72 rotates half a circle, the booster piston 4 moves and completes the boosting stroke. During this process, the power piston 5 is locked. When the booster piston 4 completes the boosting stroke, the motor 7 can unlock the power piston 5. The unlocked power piston 5 can be pushed out under the action of air pressure, thereby driving out the steel nail, and then the output shaft 72 rotates for the next half circle, the booster piston 4 is reset, and the power piston 5 is adsorbed and reset.

[0032] Combine Figure 3 、 Figure 4As shown, a pressure relief channel 6 is provided between the power piston 5 and the power cylinder body 3, one end of the pressure relief channel 6 is connected with the inner cavity inside the power piston 5, and the other end is connected to the outside of the power piston 5. Specifically, the outer diameter of the power piston 5 is smaller than the inner diameter of the inner cavity of the power cylinder body 3, and an annular pressure relief groove 51 is circumferentially provided on the outer peripheral wall of the power piston 5. The cross section of the pressure relief groove 51 is rectangular, and a limiting groove 52 is circumferentially provided on the bottom surface of the pressure relief groove 51. The cross section of the limiting groove 52 is also rectangular, and the width of the limiting groove 52 is smaller than the width of the pressure relief groove 51. The limiting groove 52 is located in the middle of the width direction of the bottom surface of the pressure relief groove 51, and a guide ring 53 is sleeved in the pressure relief groove 51. The cross section of the guide ring 53 is rectangular. The guide ring 53 is made of polytetrafluoroethylene material, and a fracture 531 is also provided on the guide ring 53, so that the guide ring 53 can expand and deform in the radial direction. A rubber ring 54 is sleeved in the limiting groove 52. The outer diameter of the rubber ring 54 in a natural state is larger than the inner diameter of the guide ring 53 in a natural state. At this time, the rubber ring 54 is located on the inner side of the guide ring 53, so the outer edge of the rubber ring 54 is tensioned against the inner circumference of the guide ring 53, that is, the rubber ring 54 can apply a radial outward expansion force to the guide ring 53. Under the action of the elastic force of the rubber ring 54, the outer circumferential wall of the guide ring 53 protrudes from the pressure relief groove 51 and fits against the inner circumferential wall of the power cylinder body 3, so that the outer circumferential wall of the guide ring 53 slides with the inner circumferential wall of the power cylinder body 3. The width of the pressure relief groove 51 is greater than the width of the guide ring 53. The diameter of the bottom surface of the pressure relief groove 51 is smaller than the inner diameter of the guide ring 53. The edges of the outer peripheral wall of the guide ring 53 are chamfered to form a guide cone 532 at both ends. The distance from the annular edge where the guide cone 532 is connected to the end face of the guide ring 53 to the inner peripheral wall of the power cylinder body 3 is greater than the gap between the outer peripheral wall of the power piston 5 and the inner peripheral wall of the power cylinder body 3. The width of the gap between the outer peripheral wall of the power piston 5 and the inner peripheral wall of the power cylinder body 3 is greater than the sum of the widths of the gaps between the side walls of the guide ring 53 and the two groove walls of the pressure relief groove 51. The width of the rubber ring 54 is greater than the width of the rubber ring 54. The width is smaller than the width of the limiting groove 52, and the inner diameter of the rubber ring 54 is larger than the bottom diameter of the limiting groove 52. Therefore, the pressure relief channel 6 includes the gap formed between the outer peripheral wall of the power piston 5 and the inner peripheral wall of the power cylinder body 3, the gap formed between the side walls of the guide ring 53 and the two groove walls of the pressure relief groove 51, the gap formed between the inner peripheral wall of the guide ring 53 and the bottom surface of the pressure relief groove 51, the gap formed between the two sides of the rubber ring 54 and the two groove walls of the limiting groove 52, and the gap formed between the inner edge of the rubber ring 54 and the bottom surface of the limiting groove 52. Of course, the fracture 531 on the guide ring 53 can also be used for gas to pass through.

[0033] Combine Figure 5As shown, a striker 56 is also provided on the outer end face of the power piston 5. Specifically, a columnar body 55 is fixed in the power piston 5. The outer end of the columnar body 55 protrudes from the outer end face of the power piston 5. A connecting groove 551 is provided on the outer end face of the columnar body 55. A rivet hole 552 is provided radially through the outer peripheral wall of the columnar body 55. The openings of the two ends of the rivet hole 552 are flared. The striker 56 is in the shape of a flat long strip. A connecting hole 561 is provided at the inner end of the striker 56. That is, the inner end of the striker 56 is inserted into the connecting groove 551. The connecting hole 561 is aligned with the rivet hole 552. A rivet 553 is passed through the rivet hole 552. The two ends of the rivet 553 are riveted to achieve the fixation of the power piston 5 and the striker 56. Figure 6 、 Figure 7 As shown, a positioning notch 562 is provided on one side edge of the striker 56, and a positioning block 8 is rotatably connected to the housing 1 through a connecting column 85. A positioning torsion spring 83 is also provided on the connecting column 85. The positioning block 8 is disc-shaped, and has a protruding positioning protrusion 81 and a yielding plane 82 on the outer circumference of the positioning block 8. The housing 1 is screwed with a positioning bolt 11 on the other side of the striker 56. The inner end of the positioning bolt 11 abuts against the edge of the striker 56, thereby limiting the position of the striker 56. That is, when the positioning protrusion 81 of the positioning block 8 is embedded in the positioning notch 562 under the action of the positioning torsion spring 83 to lock the firing pin 56, the positioning bolt 11 can prevent the firing pin 56 from shifting, so that the firing pin 56 is locked between the positioning block 8 and the positioning bolt 11. When the boosting stroke of the boosting piston 4 is completed, the motor 7 can drive the positioning block 8 to rotate through the output shaft 72, so that the positioning block 8 is disengaged from the positioning notch 562, and the positioning plane is opposite to the positioning notch 562, thereby realizing unlocking the power piston 5.

[0034] Combine Figure 8 、 Figure 9As shown, the pneumatic nail gun also includes a speed control module that can control the speed of the motor 7. The speed control module adjusts the time required for the booster piston 4 to complete the boost stroke by controlling the speed of the motor 7. The speed control module can control the motor 7 to output at least two different speeds. Specifically, a driving arm 73 is vertically fixed on the output shaft 72 driven by the motor 7. The driving arm 73 is located at the port of the booster cylinder 2. A push pin 731 is vertically fixed to the free end of the driving arm 73. A connecting rod 41 is hinged on the outer end face of the booster piston 4. The outer end of the connecting rod 41 is hinged on the push pin 731. Therefore, when the output shaft 72 rotates, it drives the driving arm 73 to rotate circumferentially, thereby driving the booster piston 4 to move back and forth. The locking cam 911 is fixed to the upper end of the rotating column 9, and the locking cam 91 has a locking arm 911 that bends and extends to the side. The side wall of the positioning block 8 is provided with a locking protrusion 84. The rotating column 9 is also provided with a locking torsion spring 92. Under the action of the locking torsion spring 92, when the positioning protrusion 81 of the positioning block 8 is embedded in the positioning notch 562 of the striker 56, the locking arm 911 can hook on the locking protrusion 84, thereby locking the positioning block 8. An unlocking swing arm 93 is fixed horizontally at the lower end of the rotating column 9. The housing 1 is hinged with a transmission swing arm 95 on the side of the unlocking swing arm 93. The free end of the transmission swing arm 95 is connected to the free end of the unlocking swing arm 93 through a connecting arm 94. The free end of the transmission swing arm 95 is provided with a transmission push plate protruding downward. 951. When the output shaft 72 rotates half a circle, the driving arm 73 swings 180°, and the booster piston 4 completes the boosting stroke. At this time, the push pin 731 can push the transmission push plate 951, thereby driving the transmission swing arm 95 to swing. The transmission swing arm 95 drives the unlocking swing arm 93 to swing through the connecting arm 94. The unlocking swing arm 93 drives the rotating column 9 to rotate, and then drives the locking block 91 to rotate. The locking arm 911 swings and disengages from the positioning protrusion 81 on the positioning block 8. Under the action of air pressure, the power piston 5 is pushed out. When the nailing is completed and the output shaft 72 continues to rotate half a circle, the booster piston 4 resets and moves, driving the power piston 5 to reset and move until the positioning notch 562 is opposite to the yield plane 82 on the positioning block 8. The positioning block 8 rotates under the action of the positioning torsion spring 83 and causes the positioning protrusion 81 to embed into the positioning notch 562 to achieve locking of the power piston 5.

[0035] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

[0036] Although the terms housing 1, retaining bolt 11, and booster cylinder 2 are frequently used herein, the use of other terms is not excluded. These terms are used solely to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

1. A pneumatic nail gun, comprising a housing (1), wherein a booster cylinder (2) and a power cylinder (3) are provided in the housing (1), wherein the booster cylinder (2) is provided with a booster piston (4) driven by a motor (7) to boost the inner cavity of the power cylinder (3), and wherein the power cylinder (3) is provided with a power piston (5) that can be locked when the booster piston (4) boosts the inner cavity, wherein the power cylinder (3) is provided with a power piston (5) that can be locked when the booster piston (4) boosts the inner cavity, characterized in that: When the boosting piston (4) completes the boosting stroke, the motor (7) can release the lock on the power piston (5); a pressure relief channel (6) is provided between the power piston (5) and the power cylinder (3); the pressure relief channel (6) includes a gap formed between the outer peripheral wall of the power piston (5) and the inner peripheral wall of the power cylinder (3); the pneumatic nail gun also includes a speed control module capable of controlling the speed of the motor (7); the speed control module adjusts the time required for the boosting piston (4) to complete the boosting stroke by controlling the speed of the motor (7); the speed control module can control the motor (7) to output at least two different speeds.

2. The pneumatic nail gun according to claim 1, characterized in that: One end of the pressure relief channel (6) is connected to the inner cavity of the power piston (5), and the other end is connected to the outer side of the power piston (5). The outer diameter of the power piston (5) is smaller than the inner diameter of the inner cavity of the power cylinder body (3). The power piston (5) is provided with a guide member that slides with the inner peripheral wall of the power cylinder body (3) to provide a guide for the sliding of the power piston (5); a speed changer (71) is provided above the motor (7), the motor shaft of the motor (7) is connected to the speed changer (71), and the output shaft (72) of the speed changer (71) is connected to the booster piston (4).

3. The pneumatic nail gun according to claim 2, characterized in that: An annular pressure relief groove (51) is formed on the outer peripheral wall of the power piston (5), and the guide member comprises a guide ring (53) sleeved in the pressure relief groove (51). The outer peripheral wall of the guide ring (53) is in sliding engagement with the inner peripheral wall of the power cylinder body (3).

4. The pneumatic nail gun according to claim 3, characterized in that: The width of the pressure relief groove (51) is greater than the width of the guide ring (53), and the diameter of the bottom surface of the pressure relief groove (51) is smaller than the inner diameter of the guide ring (53). The pressure relief channel (6) further includes a gap formed between the side walls of the guide ring (53) and the two groove walls of the pressure relief groove (51), and a gap formed between the inner peripheral wall of the guide ring (53) and the bottom surface of the pressure relief groove (51).

5. The pneumatic nailing gun according to claim 3 or 4, characterized in that: The guide ring (53) is made of polytetrafluoroethylene material and is provided with a fracture (531). A tensioning member capable of causing the guide ring (53) to radially expand and deform and to be pressed against the inner peripheral wall of the power cylinder (3) is also provided in the pressure relief groove (51).

6. The pneumatic nail gun according to claim 5, characterized in that: The tensioning member comprises a rubber ring (54). An annular limiting groove (52) is provided on the bottom surface of the pressure relief groove (51) in the circumferential direction. The width of the limiting groove (52) is smaller than the width of the pressure relief groove (51). The rubber ring (54) is sleeved in the limiting groove (52), and the outer edge of the rubber ring (54) is tensioned against the inner circumferential surface of the guide ring (53). Under the elastic force of the rubber ring (54), the outer circumferential wall of the guide ring (53) is pressed against the inner circumferential wall of the power cylinder (3).

7. The pneumatic nail gun according to claim 6, characterized in that: The limiting groove (52) is located in the middle of the width direction of the pressure relief groove (51), the width of the rubber ring (54) is smaller than the width of the limiting groove (52), and the inner diameter of the rubber ring (54) is larger than the bottom diameter of the limiting groove (52).

8. The pneumatic nailing gun according to claim 3 or 4, characterized in that: Both ends of the outer peripheral wall of the guide ring (53) are chamfered to form guide conical surfaces (532), and the distance between the annular edge where the guide conical surface (532) is connected to the end face of the guide ring (53) and the inner peripheral wall of the power cylinder body (3) is greater than the gap between the outer peripheral wall of the power piston (5) and the inner peripheral wall of the power cylinder body (3).

9. The pneumatic nail gun according to claim 4, characterized in that: The width of the gap between the outer peripheral wall of the power piston (5) and the inner peripheral wall of the power cylinder body (3) is greater than the sum of the widths of the gaps between the side walls of the guide ring (53) and the two groove walls of the pressure relief groove (51).

10. The pneumatic nailing gun according to any one of claims 1 to 4, characterized in that: A long strip-shaped striker (56) is fixedly connected to the outer end surface of the power cylinder body (3), and a positioning notch (562) is provided at one side edge of the striker (56). A disc-shaped positioning block (8) is also rotatably connected in the shell (1), and a yielding plane (82) is provided on the outer peripheral surface of the positioning block (8). A positioning torsion spring (83) is also provided between the shell (1) and the positioning block (8). When the motor (7) drives the boosting piston (4) to perform a boosting stroke, the positioning block (8) can be embedded in the positioning notch (562) under the action of the positioning torsion spring (83), so that the power piston (5) is locked. When the boosting piston (4) completes the boosting stroke, the motor (7) can drive the positioning block (8) to rotate, so that the yielding plane (82) on the positioning block (8) is opposite to the positioning notch (562).

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