Air nail gun with adjustable nailing force

Abstract

The present invention provides a pneumatic nail gun capable of adjusting the nail driving force, which belongs to the field of mechanical technology. It solves the technical problem that the adjustment accuracy of the nail driving force of the existing pneumatic nail gun cannot be maintained for a long period of time. The pneumatic nail gun includes a casing and a firing pin, and further includes a first cylinder and a second cylinder in the casing, a first piston in the first cylinder, a first air chamber defined by the first piston, a second piston in the second cylinder, the firing pin is fixedly connected to the second piston, a second air chamber defined by the second piston, the first air chamber and the second air chamber communicate with each other via a completely closed ventilation path, the first air chamber, the ventilation path and the second air chamber form an air drive structure closed to the outside, the air drive structure is provided with an air hole for communicating the air drive structure with the outside, and the casing is provided with a handle capable of adjusting the ventilation amount between the air hole and the outside. Since the air hole is a static ventilation structure, the adjustment accuracy can be maintained for a long period of time.

Description

[Technical Field]

[0001] The present invention relates to a pneumatic nail gun, which belongs to the field of mechanical engineering, and more particularly to a pneumatic nail gun with adjustable nail driving force. [Background technology]

[0002] A pneumatic nail gun is a high-pressure gas-powered tool used to drive nails. Existing pneumatic nail guns are divided into single-cylinder and double-cylinder nail guns. Single-cylinder nail guns primarily use a single cylinder to drive nails, which is typically supplied by a high-pressure gas tank or compressor. Therefore, single-cylinder pneumatic nail guns must be connected to a high-pressure gas source via a gas pipe and can only be used near the source. Double-cylinder nail guns use a single cylinder plus an additional gas cylinder to generate high-pressure gas and are powered by a built-in power source. Therefore, double-cylinder nail guns are portable and can be moved freely.

[0003] The nailing force of a single-cylinder pneumatic nail gun is adjusted by installing a balance valve in the gas passage between the single cylinder and an external high-pressure gas source to adjust the pressure input to the single cylinder. Since the adjustment is mainly made in the internal gas passage which is isolated from the outside, the high-pressure gas source does not leak to the outside.

[0004] The nailing force of a double-cylinder nail gun is adjusted mainly by adjusting the spring force and adjusting the sensor program control. The Chinese patent with publication number CN109693210A discloses a nail gun with a spring force adjustment mechanism, in which a spring and an adjustment knob are attached to a piston attached to a firing pin. When the piston contracts, the spring is compressed, and the spring force acts on the piston. The adjustment knob can be used to adjust the initial position of the spring to change the spring force. When the piston is released, different spring forces generate different nailing forces.

[0005] Another type of sensor program control adjustment is to preset the nail driving position mainly using multiple sensors, and when the piston of a cylinder that generates high pressure by gas compression reaches the preset position, the sensor detects it and the nail is driven under program control, or to detect the initial position and stroke using a sensor to calculate the nail driving position and then drive the nail under program control.

[0006] Although the above-mentioned methods for adjusting the nailing force can effectively adjust the nailing force, they cannot maintain long-term accuracy in adjusting the nailing force accuracy. Whether using a spring or a sensor, the accuracy gradually decreases over long-term use, making it difficult to maintain long-term accuracy. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Chinese Patent Application Publication No. 109693210 Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the above problems in the prior art, the present invention provides a pneumatic nail gun with adjustable nail driving force, and the technical problem to be solved is how to adjust the nail driving force accurately over a long period of time. [Means for solving the problem]

[0009] The present invention is realized by the following technical solution: A pneumatic nail gun with adjustable nail driving force includes a casing and a firing pin provided in the casing for reciprocating movement to drive a nail, the casing is provided with a locking member capable of locking or releasing the firing pin, the casing is further provided with a first cylinder and a second cylinder, the first cylinder is provided with a first piston that performs a compression stroke and a return stroke, the first piston defines a first air chamber for storing gas in the first cylinder, the first piston is driven by a motor to linearly reciprocate, and the second cylinder is provided with a second piston that reciprocates between a first position and a second position, the firing pin is fixedly connected to the second piston, and the second piston drives a second air chamber in the second cylinder. An air chamber is defined, the first air chamber and the second air chamber communicate with each other via an air vent passage, and the first air chamber, the air vent passage and the second air chamber form an air drive structure that is closed off from the outside, the air drive structure is provided with an air hole for communicating the air drive structure with the outside, and the casing is provided with a handle that can adjust the air hole and the amount of air vent to the outside, when the second piston is in the first position and the firing pin is locked, the first piston performs a compression stroke to compress the gas in the first air chamber and discharge some of the compressed gas to the outside through the air hole, and when the second piston is in the second position and the firing pin is released, the first piston performs a return stroke to return the second piston to the first position and lock it, and some of the external gas is sucked into the air drive structure through the air hole.

[0010] The operating principle of this air nail gun is as follows: when driving a nail, the first air chamber, the air passage and the second air chamber form an air drive structure, and the handle is adjusted in advance to maintain a constant air flow between the air hole on the air drive structure and the outside; when the second piston is in the first position, the piston is contracted to the bottom of the second cylinder, and the locking member locks the firing pin so that the firing pin is fixedly connected to the second piston, restricting the second piston from moving to the bottom of the second cylinder; the volume of the second air chamber is constant; the first piston performs a compression stroke, compressing the gas in the first cylinder to generate high-pressure gas; and the entire air drive structure is in a high-pressure state; because the air passage is connected to the outside, some high-pressure gas is discharged from the air drive mechanism; the actual pressure value of the high-pressure gas is smaller than the pressure value generated by the preset stroke of the first piston; By operating the handle to different positions, the actual pressure value of the high-pressure gas in the first air chamber can be adjusted to adjust the nail-driving force. After the first piston performs a compression stroke, the locking member is released, and the second piston moves at high speed under the action of the high-pressure gas to drive the firing pin and drive the nail. Then the first piston performs a return stroke. The air drive structure formed by the first air chamber, the air passage and the second air chamber is sealed except for the air hole, so during the return stroke, the first air chamber generates negative pressure against the second air chamber, and the second piston in the second cylinder is pulled back to the first position and locked by the locking member. During the return process, since the air hole is connected to the outside, the pressure in the first air chamber is also lower than atmospheric pressure, and some gas enters the first air chamber in advance to replenish the first air chamber with the gas required. The air hole and handle work together to allow only a fixed amount of outside air to enter the first air chamber, without affecting the negative pressure in the first air chamber relative to the second air chamber. This helps to calm the motor torque that gradually increases when the first piston returns, allowing the motor to operate smoothly and maintaining its operating precision. Furthermore, because the air hole is a static ventilation structure and does not move dynamically like a spring, adjustment precision can be maintained over a long period of time.

[0011] In the above-mentioned pneumatic nail gun, the second cylinder is arranged coaxially outside the first cylinder, and cylinder end caps for sealing the cylinder body of the first cylinder and the cylinder body of the second cylinder are provided at the ends of the cylinder body of the first cylinder and the cylinder body of the second cylinder, forming a first air chamber and a second air chamber on the same side, the above-mentioned air passage is located in the cylinder end cap, and the above-mentioned air hole is provided on the cylinder end cap, or on the cylinder body of the first cylinder, or on the cylinder body of the second cylinder, and the air hole is connected to the above-mentioned air passage, or the first air chamber, or the second air chamber.

[0012] In the above-mentioned pneumatic nail gun, the air hole is single and has an inner diameter of 0.5 to 5 mm, or the air hole is multiple, and the total air volume of the multiple air holes is the same as that of a single air hole with an inner diameter of 0.5 to 5 mm.

[0013] In the above-mentioned pneumatic nail gun, the handle includes a threaded rod, which is threadedly connected to the cylinder end cap, and a blocking end is provided at the end of the threaded rod. After adjusting the handle, the blocking end can be positioned at different positions within the air hole to change the amount of air in the air hole.

[0014] In the above-mentioned pneumatic nail gun, the handle includes a swing bar connected to the casing by a hinge, and a blocking plate is provided at the end of the swing bar. After adjusting the handle, the blocking plate blocks some of the air holes to change the amount of air in the air holes.

[0015] In the pneumatic nail gun, the handle includes a turntable connected to the outer end of the threaded rod, with a positioning steel ball and a spring acting on the steel ball at the edge of the turntable, and a plurality of positioning holes uniformly distributed in the circumferential direction on the outer surface of the cylinder end cap, with the steel ball abutting into the opening of one of the positioning holes under the action of the spring. When the turntable is rotated, it rotates around the axial direction of the threaded rod, and the steel ball abuts into one of the holes under the action of the spring. During rotation, the steel ball leaves the original opening and enters the next opening along a trajectory, emitting a knocking sound to notify the user that it has rotated to the next adjustment position.

[0016] In the pneumatic nail gun, the cylinder end cap is provided with a columnar mounting base, a threaded hole at one end of the mounting base, the air hole at the other end, and a vent hole at the other end, the threaded rod of the handle is threaded into the threaded hole and connected, the inner end of the threaded rod extends to the air hole opening and is positioned between the air hole and the vent hole, and a gas passage communicating with the vent hole is further provided at the bottom of the cylinder cover, and the gas passage is connected to the outside. This structure allows for exhaust and intake to the outside and also provides dust prevention.

[0017] In the above-mentioned pneumatic nail gun, a mounting base is fixedly connected to the cylinder end cap, the air hole is provided in the mounting base, the mounting base is further provided with an air vent hole communicating with the air hole, the air vent hole is communicating with the outside, the air hole is movably connected to an air vent pole, the air vent pole includes an air vent rod, the air vent rod includes an air hole and an inner air hole communicating with the air hole, the air vent hole is communicating with the first air chamber, the air vent pole is connected to a handle, and the inner air hole moves with the air hole when the handle is adjusted, and the inner surface of the air hole and the air hole form a conductive or closed state via the inner air hole. After the handle is rotated a certain number of times, the inner surface of the through-hole and the external air hole form a partial conductive state, which changes the ventilation volume between the air-driven structure and the outside. When the operator unintentionally touches the handle, the handle rotates to change the position of the blocking part, preventing the air-driven structure from communicating with the outside. At the same time, the ventilation rod is located within the through-hole of the mounting base, ensuring the sealing of the mounting base and improving the accuracy of adjusting the nailing force of the nail gun.

[0018] In the pneumatic nail gun, the cylinder end caps include an inner end cap and an outer end cap, and the outer end cap is tightly attached to the outer surface of the inner end cap to form the ventilation passage between the inner end cap and the outer end cap, and the gas passage is provided below the ventilation passage. With this structure, external gas enters the first air chamber from the bottom of the first cylinder upward, ensuring the purity of the entered gas.

[0019] In the above-mentioned pneumatic nail gun, the gas passage includes a cylindrical fixed base provided on the outer surface of the inner end cap, the mounting base is inserted into the fixed base and sealed therewith, the fixed base is provided with a ventilation groove communicating with the ventilation hole, a plurality of ribs are further provided on the outer side of the fixed base on the outer surface of the inner end cap, recessed cavities are provided between the ribs, and holes communicating with the outside are provided on the outer edge of the inner end cap, the ventilation groove and the recessed cavities are communicated with the holes. A large-volume recess is provided between the ventilation groove and the holes, so that the high-pressure gas discharged from the first air chamber can form a buffer to reduce noise.

[0020] In the above-mentioned pneumatic nail gun, a first protrusion is provided on the inner surface of the inner end cap, and the first protrusion is inserted into and sealed to the cylinder body of the first cylinder. A second protrusion is provided on the inner surface of the inner end cap, and the second protrusion is provided with a first through hole that penetrates the inner end cap. A second through hole that penetrates the inner end cap is provided in the second protrusion. A seal ring is provided between the outer end cap and the inner end cap. The seal ring surrounds the first and second through holes. The outer end cap is provided with a groove that communicates the first and second through holes.

[0021] In the above-mentioned pneumatic nail gun, the mounting base includes a ventilation ring communicating with the air hole, the ventilation ring has a ventilation hole, the ventilation pole includes a screw, the mounting base has a threaded hole, the screw is screwed into the threaded hole, and the ventilation pole is connected to the handle via a tab, the ventilation pole moves within the air hole by relative rotation of the screw and the threaded hole, and the air hole is connected to the ventilation ring or is closed via the inner air hole.

[0022] In the above-mentioned pneumatic nail gun, a flange is provided at the end of the mounting base, the fixed base includes a mounting groove that matches the shape of the flange, the flange is positioned within the mounting groove, and an annular groove is further opened on the outer wall of the mounting base, and the annular groove communicates with the above-mentioned ventilation groove.

[0023] In the above-mentioned pneumatic nail gun, the nail gun includes a housing, a fixing groove formed in the housing, a cover plate attached to a notch in the fixing groove, a movable rod disposed in the fixing groove, a spring groove formed in one end of the movable rod, the spring 2 being attached to a cylinder end cap, and the other end of the movable rod being a spherical tab. The handle includes a connecting rod and a tab turntable connected to the outer end of the connecting rod, the connecting rod being connected to the tab, and a spherical groove formed in the tab turntable that matches the shape of the spherical tab, the spherical tab passing through a U-shaped opening in the fixing groove and abutting against the spherical groove.

[0024] In the above-mentioned pneumatic nail gun, the housing is further provided with a rotation groove having an opening, the tub turntable rotates in the rotation groove, and numbers corresponding to the spherical grooves are further provided on the end surface of the tub turntable, and the numbers are provided at intervals on the touch pad of the tub turntable. [Effects of the Invention]

[0025] Compared with the prior art, this pneumatic nail gun has the following advantages: 1. This pneumatic nail gun has an air hole in the air drive structure that communicates with the outside, allowing the nailing force to be adjusted. This helps to calm the motor torque that gradually increases when the first piston returns, ensuring smooth motor operation and maintaining motor operating accuracy. Since the air hole is a static ventilation structure and does not move dynamically like a spring, adjustment accuracy can be maintained for a long period of time. 2. When this pneumatic nailer exhausts and takes in air through the air hole, an air groove is provided on the outside of the air hole, and the gas passages such as the internal cavity and holes eliminate exhaust noise. When taking in air, the ash-free layer is prevented from entering the first air chamber, and long-term accuracy can be maintained. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 2 is a schematic diagram showing the cross-sectional structure of the pneumatic nail gun. [Figure 2] FIG. 2 is a schematic diagram showing a partially exploded three-dimensional structure of the pneumatic nail gun. [Figure 3] FIG. 3 is a schematic diagram showing an enlarged three-dimensional structure of a cylinder end cap portion of the pneumatic nail gun in FIG. 2. [Figure 4] FIG. 2 is a schematic diagram showing an enlarged three-dimensional structure of part A in FIG. [Figure 5] FIG. 2 is a schematic structural diagram showing the state of the air drive structure when the first piston performs a compression stroke. [Figure 6] FIG. 2 is a schematic structural diagram showing the state of the air drive structure when the first piston performs a compression stroke. [Figure 7] FIG. 10 is a schematic structural diagram showing the state of the air-driven structure after nailing. [Figure 8] FIG. 10 is a schematic structural diagram showing the state of the air drive structure when the first piston performs a return stroke. [Figure 9] FIG. 10 is a schematic structural diagram of the air drive structure returning to its initial state after the first piston has performed a return stroke. [Figure 10] FIG. 2 is a schematic diagram showing a partially exploded structure of the pneumatic nailing machine according to a second embodiment of the present invention. [Figure 11] FIG. 11 is a schematic diagram showing a partially enlarged three-dimensional structure of a cylinder end cap of the pneumatic nail gun of FIG. 10. [Figure 12] FIG. 10 is a schematic diagram showing an enlarged three-dimensional structure of the mounting base and ventilation column in Example 2 of this pneumatic nail gun. [Figure 13] FIG. 10 is a schematic diagram showing an enlarged cross-sectional structure of a cylinder end cap in Example 2. [Figure 14] FIG. 10 is a schematic diagram showing the cross-sectional structure of the nail driver in Example 2 when the inner air hole and the vent hole are not electrically connected. [Figure 15] FIG. 10 is a schematic diagram showing the cross-sectional structure of the nail driver in Example 2 when the inner air hole and the ventilation hole are partially connected to each other. [Figure 16] FIG. 10 is a schematic diagram showing the cross-sectional structure of the nail driver in Example 2 when the inner air hole and the vent hole are completely connected to each other. [Figure 17]FIG. 10 is a schematic diagram showing the three-dimensional structure of the nail driver according to a third embodiment of the present invention. [Figure 18] FIG. 10 is a schematic diagram showing an exploded structure of Example 3. [Figure 19] FIG. 10 is an exploded schematic view of a part of the structure of Example 3. [Figure 20] FIG. 10 is an exploded schematic view of a part of the structure of Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be further described below with reference to the drawings and embodiments. [Example]

[0028] As shown in Figure 1, the air nail gun includes a casing 1, a firing pin 2 mounted in the casing 1 and adapted to move back and forth to drive nails, and a locking member 3 mounted in the casing 1 for locking or releasing the firing pin 2. The locking member 3 includes a locking hook, and an engagement groove is provided on the side of the firing pin 2. When in the locked state, the locking hook engages with the engagement groove, so that the firing pin 2 is held in the locked state and cannot be moved. A first cylinder 4 and a second cylinder 5 are further provided within the casing 1, a first piston 41 that performs a compression stroke and a return stroke is provided within the first cylinder 4, a first air chamber 42 for storing gas within the first cylinder 4 is defined by the first piston 41, a piston rod 411 is connected to the first piston 41, and the piston rod 411 is connected to a crank 412, a motor 6 provided within the casing 1 is connected to a gear reducer 61, the output shaft of the gear reducer 61 is connected to the crank 412, the piston rod 411 and the crank 412 form a crank link structure, and the rotational force of the motor 6 is converted into power that drives the first piston 41 to move back and forth linearly. A second piston 51 is provided in the second cylinder 5 and is capable of reciprocating between a first position and a second position. The first position is a position where the second piston 51 is located when the firing pin 2 is locked, and the second position is a position where the second piston 51 is located after the firing pin has struck the nail. The firing pin 2 is fixedly connected to the second piston 51, and a second air chamber 52 is defined in the second cylinder 5 by the second piston 51. The first air chamber 42 and the second air chamber 52 communicate with each other via a completely closed air passage 8, and the first air chamber 42, the air passage 8 and the second air chamber 52 form an air drive structure that is closed off from the outside. A removable battery 10 is provided at the lower end of the grip of the casing 1, and the battery 10 supplies power to a motor control panel 11. A button 12 is also provided at the lower end of the grip of the casing 1, and the button 12 is also connected to the motor control panel 11. When the button 12 is pressed, the motor control panel 11 controls the motor 6 to drive the first piston 41 to perform a compression stroke and a return stroke. A nail box 13 is also provided at the front end of the casing 1, and a nail in the nail box 13 automatically rises in front of the firing pin 2 under the action of a spring.After the first piston 41 performs a compression stroke, the release mechanism disengages the locking hook from the engagement groove of the firing pin 2, releasing the firing pin 2 and the second piston 51. The second piston 51 moves at high speed under the action of high pressure, driving the firing pin 2 to strike the nail in front of the firing pin 2, completing one nail driving operation. After that, the first piston 41 performs a return stroke, and under the action of negative pressure, the second piston 51 returns from the first position to the second position, locking the firing pin 2 again with the locking hook. This process is repeated to achieve continuous nail driving.

[0029] As shown in Figure 2 in conjunction with Figure 1, Figure 2 is a three-dimensional exploded view of this pneumatic nail gun. The second cylinder 5 is located above the first cylinder 4, the first cylinder 4 and the second cylinder 5 are arranged coaxially, and cylinder end caps 9 are provided at the end of the cylinder body of the first cylinder 4 and the end of the cylinder body of the second cylinder 5 to seal the cylinder body of the first cylinder 4 and the cylinder body of the second cylinder 5. The end caps of the first cylinder 4 and the second cylinder 5 are the same cylinder end cap 9 and are attached to one side of the first cylinder 4 and the second cylinder 5, forming a first air chamber 42 and a second air chamber 52 on the same side, and an air passage 8 is located within the cylinder end cap 9. The cylinder end caps 9 include an inner end cap 91 and an outer end cap 92. The inner surface of the inner end cap 91 is provided with a first protrusion 911 that is inserted into and hermetically connected to the cylinder body of the first cylinder 4, and a second protrusion 912 that is inserted into and hermetically connected to the cylinder body of the second cylinder 5. The first protrusion 911 is provided with a first through hole 913 that penetrates the inner end cap 91, and the second protrusion 912 is provided with a second through hole 914 that penetrates the inner end cap 91. A seal ring 915 is provided between the outer end cap 92 and the inner end cap 91. The seal ring 915 surrounds the first through hole 913 and the second through hole 914 within the seal ring 915. The inner surface of the outer end cap 92 is provided with a groove 921 that connects the first through hole 913 and the second through hole 914. With this structure, the outer end cap 92 is tightly attached to the outer surface of the inner end cap and is fixed to the cylinder body of the first cylinder 4 and the cylinder body of the second cylinder 5 via screws, and after the inner end cap 91 and the outer end cap 92 are fixed, the above-mentioned ventilation path 8 is formed between the inner end cap 91 and the outer end cap 92.

[0030] As shown in FIGS. 3 and 4 , a single air hole 7 communicating with the ventilation passage 8 is provided in the cylinder end cap 9. The air hole 7 has an inner diameter of 0.5 to 5 mm. The casing 1 is provided with a handle 14 for adjusting the amount of air flowing through the air hole 7 and the outside. The handle 14 includes a threaded rod 141 that is threadedly connected to the cylinder end cap 9. The inner end of the threaded rod 141 is a blocking end. By adjusting the handle, the blocking end can be positioned at a different position within the air hole 7, thereby changing the amount of air flowing through the air hole 7. In an alternative structure, the air hole 7 may be provided on the cylinder body of the first cylinder 4 or the cylinder body of the second cylinder 5. The air hole 7 communicates with the first air chamber 42 or the second air chamber 52. There may be multiple air holes 7, and the total air flow through the multiple air holes has the same or similar amount of air as a single air hole with an inner diameter of 0.5 to 5 mm. To enhance strength, the inner end cap 91 and outer end cap 92 of the cylinder end cap 9 are provided with columnar mounting bases 94 made of a metal material such as copper. The mounting bases 94 are mounted inside the plastic cylinder end caps 9, with a threaded hole at one end and an air hole 7 at the other end, and an air inlet hole 145a at the other end. A threaded rod 141 of the handle 14 is threaded into the threaded hole and connected to the handle 14, with the inner end of the threaded rod 141 extending to the opening of the air hole 7 and positioned between the air hole 7 and the air inlet hole 145a. The handle 14 includes a turntable 142 connected to the outer end of the threaded rod 141. A positioning steel ball 143 and a spring 144 acting on the steel ball 143 are further provided on the edge of the turntable 142. A plurality of positioning holes 922 are formed on the outer surface of the cylinder end cap 9, uniformly spaced in the circumferential direction, and the steel ball 143 is pressed into the opening of one of the positioning holes 922 under the action of the spring 144. When the turntable 142 is rotated, it rotates around the axial direction of the threaded rod 141, and the steel ball 143 is abutted against one opening under the action of the spring 144. During the rotation, the steel ball 143 moves away from the original opening and enters the next opening along a trajectory, making a knocking sound to notify the user that it has rotated to the next adjustment position and is being positioned.

[0031] The air hole 7 is located in a gas passage 93 in the cylinder end cap 9, connecting the air-driven structure to the outside. The gas passage 93 is located in the lower part of the cylinder end cap 9, below the ventilation path 8. Specifically, the gas passage 93 includes a cylindrical fixed base 916 provided on the outer surface of the inner end cap 91. The mounting base 94 is inserted into the fixed base 916 and sealed therewith. The fixed base 916 is provided with a ventilation groove 917 that communicates with the air inlet hole 145a. A plurality of ribs 918 are further provided on the outer side of the fixed base 916 on the outer surface of the inner end cap 91. Recessed cavities 95 are provided between the ribs 918. A hole 919 that communicates with the outside is further provided on the outer edge of the inner end cap 91. The ventilation groove 917, the recessed cavities 95, and the hole 919 are in communication with each other.

[0032] As shown in Figures 5 to 9, the operating process of the present invention is as follows: the first air chamber 42, the air passage 8, and the second air chamber 52 form an air drive mechanism; the positions of the first piston 41 and the second piston 51 shown in Figure 1 are in the initial state; when the handle 14 is adjusted in advance, the air hole 7 in the air drive mechanism maintains the amount of air flowing to the outside within a predetermined range, and the second piston 51 is located in the first position; that is, the first piston 51 retracts to the bottom of the second cylinder 5, and the locking member 3 with the locking hook locks the firing pin 2.

[0033] As shown in FIG. 5, the first piston 41 performs a compression stroke, compressing the gas in the first cylinder 4 to generate high-pressure gas, and the entire air-driven structure is then under high pressure. Since the air hole 7 is connected to the outside through the gas passage 93, some of the high-pressure gas is discharged to the outside through the ventilation groove 917, the recessed cavity 95, and the hole 919. The actual pressure value of the high-pressure gas is smaller than the pressure value generated by the preset stroke of the first piston 41, thereby realizing adjustment of the nail driving force.

[0034] As shown in Figures 6 and 7, after the first piston 41 performs a compression stroke, the release mechanism moves the locking hook out of the engagement groove of the firing pin 2, the locking member 3 enters a released state, and the firing pin 2 and the second piston 51 are both in a released state. The second piston 51 moves at high speed under the action of high pressure, and the firing pin 2 is driven to strike the nail in front of the firing pin 2, completing one nail-driving operation. At this time, the second piston 51 is in the second position.

[0035] As shown in FIG. 8 , the first piston 41 performs a return stroke. Because the air-driven structure formed by the first air chamber 42, the air passage 8, and the second air chamber 52 is sealed except for the air hole 7, the first air chamber 42 generates negative pressure relative to the second air chamber 52 during the return stroke, causing the second piston 51 in the second cylinder 5 to move to the first position. During the return stroke, the air hole 7 is connected to the outside, so the pressure in the first air chamber 42 is also lower than atmospheric pressure. Some gas enters the first air chamber 42 in advance through the air vent groove 917, the recessed cavity 95, and the hole 919, pre-replenishing the first air chamber 42 with the necessary gas. The cooperation of the air hole and the handle ensures that only a certain amount of external air enters the first air chamber 42, preventing any negative pressure in the first air chamber 42 relative to the second air chamber 52. This stabilizes the torque of the motor 6, which gradually increases during the return stroke of the first piston 41, ensuring smooth motor 6 operation and maintaining the motor's operating precision.

[0036] As shown in FIG. 9, when the first piston 41 returns to its initial position, the second piston 51 returns to its first position under the action of negative pressure, and the firing pin is locked again by the locking member 3, completing one nail driving cycle. [Example]

[0037] 10 to 13 , the nail gun of Example 2 has essentially the same structure as Example 1, except for the following: in the nail gun of Example 2, the mounting base 94 and the fixed base 916 have different structures; the mounting base 94 includes a flange 943, which has a hexagonal structure and is attached to a mounting groove 96 of the inner end cap 91; the mounting base 94 includes an air hole 7, which communicates with a vent ring 941; the vent ring 941 has a vent hole 71, which communicates with the air inlet hole 145a; and an annular groove 944 on the outer wall of the mounting base 94. In this example, the inner end cap 91 is further provided with a vent groove 917 having a different structure, and the annular groove 944 communicates with the vent groove 917.

[0038] The ventilation column 145 is located within the mounting base 94, and includes a ventilation rod. The ventilation rod is provided with an air inlet hole 145a and an inner air hole 145b communicating with the air inlet hole 145a, and the air inlet hole 145a communicates with the first air chamber 42. The ventilation column 145 is provided with a screw 145c, and the mounting base 94 is further provided with a threaded hole 942. The screw 145c is screwed into the threaded hole 942, and the ventilation column 145 is connected to the handle 14 via a tab 145d. When the handle 14 is rotated, the screw 145c and the threaded hole 942 rotate relative to each other, and the ventilation column 145 moves within the air hole 7.

[0039] The operating principle of this embodiment, as shown in Figures 13 to 16, is specifically as follows: the nailing force of the nail gun is adjusted by adjusting the handle 14 to change the air drive structure and the amount of ventilation of the external atmosphere; the ventilation amount is mainly determined by changing the overlapping degree of the inner air hole 145b and the ventilation ring 941; as shown in Figure 14, when the nail gun is in the initial state, the gas in the first air chamber 42 diffuses into the air inlet hole 145a of the ventilation column 145; at this time, the inner air hole 145b is located inside the air hole 7; The inner air hole 145b and the ventilation ring 941 are completely offset, and the air drive structure and the outside atmosphere are kept in an isolated state. After the piston in the first cylinder 4 completes the compression stroke, the actual pressure value of the high-pressure gas in the first air chamber 42 is equal to the pressure value generated by the preset stroke of the first piston 41. As shown in Figure 15, when adjusting the handle 14, the ventilation rod 145 rotates with the mounting base 94, and the inner air hole 145b on the ventilation rod and the ventilation ring 941 partially overlap, and the gas in the air drive structure is introduced into the air intake. The first air chamber 42 communicates with the outside atmosphere through the hole 145a, the inner air hole 145b, the ventilation ring 941, and the ventilation hole 71. At this time, the actual pressure value of the high-pressure gas in the first air chamber 42 is smaller than the pressure value generated by the preset stroke of the first piston 41. As shown in FIG. 16, when the inner air hole 145b and the ventilation ring 941 are completely overlapped by adjusting the handle 14, the actual pressure value of the high-pressure gas in the first air chamber 42 is smaller than the pressure value generated by the preset stroke of the first piston 41. In this embodiment, the handle 14 rotates a certain number of times and the inner air hole 145b and the ventilation ring 941 are partially aligned, the air drive structure and the external ventilation amount need to be changed, which prevents the operator from accidentally touching the handle 14 and changing the position of the blocking part when the handle 14 is rotated, thereby preventing the air drive structure from communicating with the outside; at the same time, the ventilation rod is located inside the air hole 7 of the mounting base 94, which ensures sealing inside the mounting base 94 and improves the accuracy of adjusting the nailing force of the nail gun. [Example]

[0040] 17 to 20, the second embodiment has substantially the same structure as the first embodiment, except for the following points: the tab 145d adopts the structure of FIG. 19; the handle 14 includes a connecting rod 14a connected to the tab 145d and a tab turntable 14b connected to the outer end of the connecting rod 14a; a fixing groove 15a is provided on the housing 15 of the nail gun; the cover plate 16 is attached to the notch of the fixing groove 15a; a movable rod 17 is provided in the fixing groove 15a; one end of the movable rod 17 is provided with a spring groove 17a; a spring 218 is mounted in the spring groove 17a; the spring 218 abuts against the cylinder end cap 9; the other end of the movable rod 17 is a spherical tab 17b; and the tab turntable 14b has a spherical groove matching the shape of the spherical tab 17b. The spherical tab 17b is abutted against the spherical groove 14c through the U-shaped opening 15a1 of the fixing groove 15a. The housing 15 is further provided with a rotation groove 15b. The tab turntable 14b rotates within the rotation groove 15b. Numbers corresponding to the spherical grooves 14c are further provided on the end surface of the tab turntable 14b, where each number indicates one spherical groove 14c. The numbers are provided at intervals on the touch pad 14b1 of the tab turntable 14c. The rotation groove 15b is provided with an opening 15b1. When adjusting the tab turntable 14b, the user places the opening 15b1 on the touch pad 14b1 to rotate the tab turntable 14c. The tab turntable 14c is further provided with a rotation mark to indicate the rotation direction.

[0041] The specific embodiments described herein are merely illustrative of the spirit of the present invention, and those skilled in the art to which the present invention pertains may make various modifications, additions, or similar substitutions to the specific embodiments described without departing from the spirit of the present invention and the scope defined in the claims.

[0042] In this specification, terms such as casing, firing pin, crank, and first cylinder are frequently used, but the use of other terms is not excluded. These terms are merely used to describe the present invention and its essence, and any additional limitations on them would be contrary to the spirit of the present invention. [Explanation of symbols]

[0043] 1 casing 2 firing pins 3 Locking member 4. No. 1 Cylinder 41 First piston 411 Piston rod 412 Crank 42 First air chamber 5. No. 2 cylinder 51 Second piston 52 Second air chamber 6 motors 61 Gear reducer 7 Air Holes 71 Ventilation holes 8 Ventilation Channel 9 Cylinder end cap 91 Inner end cap 911 First convex part 912 Second convex part 913 First through hole 914 First through hole 915 Seal Ring 916 Fixed base 917 Ventilation groove 918 Rib 919 holes 92 outer end cap 921 Groove 922 Positioning hole 93 Gas passage 94 Mounting base 941 Ventilation Ring 942 screw hole 943 flange 944 Annular groove 95 Concave cavity 96 Mounting groove 10 batteries 11 Motor Control Panel 12 buttons 13 Nail box 14 Handle 141 Threaded Rod 142 Turntable 143 Steel ball 144 Spring 14a Connecting rod 14b Tab Turntable 14b1 Touchpad 14c spherical groove 145 Ventilation column 145a Air intake hole 145b Inner air hole 145c screw 145d tab 15 Housing 15a Fixed groove 15a1 U-shaped opening 15b Rotating groove 15b1 opening 16 Cover plate 17 Movable rod 17a Spring groove 17b spherical tab 18 Spring 2

Claims

1. The gun includes a casing (1) and a firing pin (2) mounted in the casing (1) and adapted to reciprocate to drive a nail. The casing (1) further includes a first cylinder (4) and a second cylinder (5). The first cylinder (4) is provided with a first piston (41) capable of performing a compression stroke and a return stroke. The first piston (41) defines a first air chamber (42) for storing gas within the first cylinder (4). The first piston (41) is driven by a motor (6) to reciprocate linearly. a second piston (51) capable of reciprocating between a first position and a second position is provided in the second cylinder (5), the firing pin (2) is fixedly connected to the second piston (51), a second air chamber (52) is defined in the second cylinder (5) by the second piston (51), the first air chamber (42) and the second air chamber (52) communicate with each other via an air passage (8), and the first air chamber (42), the air passage (8) and the second air chamber (52) form an air-driven structure that is closed to the outside except for an air hole, The air-driven structure is provided with an air hole (7) for communicating the air-driven structure with the outside, and the casing (1) is provided with a handle (14) capable of adjusting the amount of air vent between the air hole (7) and the outside, and when the second piston (51) is in the first position and the firing pin (2) is locked, the first piston (41) performs a compression stroke to compress the gas in the first air chamber (42) and discharge some of the compressed gas to the outside through the air hole (7), and when the second piston (51) is in the second position and the firing pin (2) is released, the first piston (41) performs a return stroke to return the second piston (51) to the first position and lock it, and some of the outside gas is sucked into the air-driven structure through the air hole (7). This air nail gun has adjustable nailing force.

2. 2. The pneumatic nail gun with adjustable nailing force according to claim 1, wherein the second cylinder (5) is arranged integrally with the first cylinder (4) so ​​that their axes are parallel to each other outside the first cylinder (4), and cylinder end caps (9) for sealing the cylinder bodies of the first cylinder (4) and the second cylinder (5) are provided at the ends of the cylinder body of the first cylinder (4) and the cylinder body of the second cylinder (5), the air passage (8) is located in the cylinder end caps (9), and the air hole (7) is provided in the cylinder end caps (9), or the cylinder body of the first cylinder (4), or the cylinder body of the second cylinder (5), and the air hole (7) communicates with the air passage (8), or the first air chamber (42), or the second air chamber (52).

3. The pneumatic nail gun with adjustable nailing force according to claim 2, characterized in that the air hole (7) is a single hole with an inner diameter of 0.5 to 5 mm, or the air holes (7) are multiple holes.

4. The adjustable nailing force pneumatic nail gun according to claim 2, characterized in that the handle (14) includes a threaded rod (141), which is threadedly connected to the cylinder end cap (9), and the inner end of the threaded rod (141) is a blocking end, and by adjusting the handle (14), the blocking end can be positioned in different positions to block the air hole (7) and change the amount of air in the air hole (7).

5. The pneumatic nail gun with adjustable nailing force according to claim 1, 2 or 3, characterized in that the handle (14) is connected to a swing bar on the casing (1) by a hinge, and a blocking plate is provided at the end of the swing bar, and by adjusting the handle (14), the blocking plate can block some of the air holes (7) and change the amount of air in the air holes (7).

6. The pneumatic nail gun with adjustable nailing force according to claim 4, characterized in that the handle (14) includes a turntable (142) fixedly connected to the outer end of the threaded rod (141), the turntable (142) is provided with positioning steel balls (143) and springs (144) acting on the steel balls (143), the outer surface of the cylinder end cap (9) is provided with a number of positioning holes (922) uniformly distributed in the circumferential direction, and the steel balls (143) are abutted into the openings of one of the positioning holes (922) under the action of the springs (144).

7. 7. The pneumatic nail gun with adjustable nail driving force according to claim 6, wherein the cylinder end cap (9) is provided with a columnar mounting base (94), a threaded hole at one end of the mounting base (94), the air hole (7) at the other end of which is provided with a vent hole (71), a threaded rod (141) of the handle (14) is threaded into the threaded hole to connect, the inner end of the threaded rod (141) extending to the opening of the air hole (7) and positioned between the air hole (7) and the vent hole (71), a gas passage (93) communicating with the vent hole (71) is provided at the bottom of the cylinder end cap (9), and the gas passage (93) is connected to the outside.

8. A mounting base (94) is fixedly connected to the cylinder end cap (9), the air hole (7) is provided in the mounting base (94), the mounting base (94) is further provided with a ventilation hole (71) communicating with the air hole, the ventilation hole (71) communicating with the outside, a ventilation column (145) is movably connected to the air hole (7), the ventilation column (145) includes a ventilation rod, and the ventilation rod communicates with the air introduction hole (145a) and the air introduction hole (145a). The pneumatic nail gun with adjustable nailing force according to claim 6, further comprising an inner air hole (145b) for connecting the air inlet hole (145a) to the first air chamber (42), the air intake hole (145a) being connected to the handle (14), and the air vent column (145) being connected to the handle (14), the inner air hole (145b) being moved by adjusting the handle (14), and the inner circumferential surface of the air hole (7) and the air vent hole (71) being in a conducting or closed state via the inner air hole (145b).

9. The pneumatic nail gun with adjustable nailing force according to claim 7 or 8, characterized in that the cylinder end cap (9) includes an inner end cap (91) and an outer end cap (92), the outer end cap (92) is fixed to the outer surface of the inner end cap (91) to form the above-mentioned ventilation channel (8) between the inner end cap (91) and the outer end cap (92), and the gas passage (93) is provided below the ventilation channel (8).

10. 10. The pneumatic nail gun with adjustable nailing force according to claim 9, wherein the gas passage (93) includes a cylindrical fixed base (916) provided on the outer surface of the inner end cap (91), the mounting base (94) is inserted into the fixed base (916) and sealed therewith, the fixed base (916) is provided with an air vent groove (917) communicating with the air vent hole (71), a plurality of ribs (918) are provided on the outer side of the fixed base (916) on the outer surface of the inner end cap (91), concave cavities (95) are formed between the ribs (918), and holes (919) communicating with the outside are provided on the outer edge of the inner end cap (91), the air vent groove (917), the concave cavities (95) and the holes (919) communicate with each other.

11. The inner surface of the inner end cap (91) is provided with a first protrusion (911) that is inserted into the cylinder body of the first cylinder (4) and fitted and connected thereto, and a second protrusion (912) that is inserted into the cylinder body of the second cylinder (5) and fitted and connected thereto, and the first protrusion (911) is provided with a first through-hole (913) that penetrates the inner end cap (91), and the second protrusion (912) is provided with a second through-hole (914) that penetrates the inner end cap (91).

11. The pneumatic nail gun with adjustable nailing force according to claim 10, wherein a seal ring (915) is provided between the outer end cap (92) and the inner end cap (91), the seal ring (915) surrounds the first through hole (913) and the second through hole (914) within the seal ring (915), and the outer end cap (92) is provided with a groove (921) that connects the first through hole (913) and the second through hole (914).

12. 9. The pneumatic nail gun with adjustable nailing force according to claim 8, wherein the mounting base (94) includes a ventilation ring (941) communicating with the air hole (7), the ventilation ring (941) has ventilation holes (71), the ventilation pole (145) includes a screw (145c), the mounting base (94) further includes a threaded hole (942), the screw (145c) is screwed into the threaded hole (942), the ventilation pole (145) is connected to the handle via a tab (145d), the ventilation pole (145) moves within the air hole (7) by relative rotation of the screw (145c) and the threaded hole (942), and the air hole (7) is in a conductive or closed state with the ventilation ring (941) through the inner air hole (145b).

13. 13. The pneumatic nail gun with adjustable nailing force according to claim 12, wherein the mounting base (94) has a flange (943) at an end thereof, the fixed base (916) has a mounting groove (96) whose shape matches the flange (943), the flange (943) is positioned within the mounting groove (96), the mounting base (94) further has an annular groove (944) on its outer wall, the fixed base (916) has an air vent groove (917), and the annular groove (944) communicates with the air vent groove (917) through an air vent hole (71).

14. A mounting base (94) is fixedly connected to a cylinder end cap (9), the air hole (7) is provided in the mounting base (94), the mounting base (94) is further provided with an air vent hole (71) communicating with the air hole, the air vent hole (71) communicates with the outside, a ventilation column (145) is movably connected to the air hole (7), the ventilation column (145) includes a ventilation rod, the ventilation rod includes an air introduction hole (145a) and an inner air hole (145b) communicating with the air introduction hole (145a), the air introduction hole (145a) communicates with a first air chamber (42), The nail gun further includes a housing (15), a fixing groove (15a) formed in the housing (15), a cover plate (16) attached to a notch in the fixing groove (15a), a movable rod (17) provided in the fixing groove (15a), one end of the movable rod (17) having a spring groove (17a) for receiving a spring 2 (18), the spring 2 (18) abutting against the cylinder end cap (9), and the other end of the movable rod (17) having a spherical tab (17a). b), the handle (14) includes a connecting rod (14a) and a tab turntable (14b) connected to the outer end of the connecting rod (14a), the connecting rod (14a) is connected to a tab (145d) of the ventilation column (145), the tab turntable (14b) has a spherical groove (14c) that matches the shape of the spherical tab (17b), and the spherical tab (17b) passes through the U-shaped opening (15a1) of the fixing groove (15a) and abuts against the spherical groove (14c); The pneumatic nail gun with adjustable nailing force according to claim 2, characterized in that, under adjustment of the handle (14), the inner air hole (145b) moves the air hole (7), and the inner surface of the air hole (7) and the ventilation hole (71) form a conductive or closed state through the inner air hole (145b).

15. 15. The pneumatic nail gun with adjustable nailing force according to claim 14, characterized in that the housing (15) is further provided with a rotation groove (15b) having an opening (15b1), the tub turntable (14b) rotates within the rotation groove (15b), and numbers corresponding to the spherical grooves (14c) are provided on an end surface of the tub turntable (14b), and the numbers are provided at intervals on a touch pad (14b1) of the tub turntable (14b).

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