Fastening tool

Abstract

The application provides a fastening tool, comprising a housing, a motor, an impact assembly, a first cylinder, a second cylinder and a second piston, the second cylinder is sleeved outside the first cylinder, the impact assembly comprises a first piston and a hitting component connected with the first piston, the second piston is provided with a first through hole and has an inner wall surface and an outer wall surface, the first cylinder is arranged through the first through hole, and the inner wall surface is provided with a first recess for accommodating a sealing element and a second recess at an axial position different from that of the first recess.

Description

Technical Field

[0001] This utility model relates to the field of power tool technology, specifically to a fastening tool. Background Technology

[0002] A nail gun is a fastening tool used to quickly drive nails into a workpiece. Whether the nail can be driven into the workpiece completely is often closely related to the power used during nailing, the type of nail, and the material of the workpiece. When the parameters are not matched, situations such as the nail not being fully driven into the workpiece (nailing out) or the nail bending (nailing collapse) will occur, affecting the quality of nailing.

[0003] This section provides background information related to this application, which is not necessarily prior art. Utility Model Content

[0004] This application provides a fastening tool, comprising:

[0005] case;

[0006] The motor is housed within the casing;

[0007] An impact assembly, the impact assembly including a first piston and a striking component connected to the first piston, the striking component being used to strike a fastener;

[0008] The first cylinder has a first chamber, and the first piston is disposed in the first chamber;

[0009] The second cylinder is fitted outside the first cylinder and forms a second chamber that can communicate with the first chamber;

[0010] The second piston is disposed in the second chamber and is driven by the motor to reciprocate in the second chamber. The second piston is provided with a first through hole and has an inner wall surface surrounding the first through hole and an outer wall surface surrounded by the second cylinder. The first cylinder is disposed through the first through hole.

[0011] The inner wall surface is provided with a first recess and a second recess for accommodating a seal, the second recess being located at a different position relative to the first recess along the inner wall surface.

[0012] In one possible implementation, the first recess and the second recess are annular grooves.

[0013] In one possible implementation, the annular groove has a rectangular cross-section, with its opening facing the radial direction of the first through hole.

[0014] In one possible implementation, a first seal is provided in the first recess, and a second seal is provided in the second recess.

[0015] In one possible implementation, the first seal and / or the second seal is one of an O-ring, an X-ring, a Y-ring, a V-ring, or a U-ring.

[0016] In one possible implementation, the first cylinder is made of plastic.

[0017] In one possible implementation, the wall thickness of the first cylinder is less than 2 mm.

[0018] In one possible implementation, the minimum distance between the first recess and the second recess along the axial direction of the first through hole is at least 1 mm.

[0019] In one possible implementation, the maximum distance between the first recess and the second recess along the axial direction of the first through hole is at least 15% of the length of the second piston.

[0020] In one possible implementation, the second piston is provided with one of a magnet or a sensor, the other of which is stationary relative to the housing.

[0021] The advantages of this application are: for a fastening tool in which the first cylinder is located inside the second cylinder, the second piston is arranged around the first cylinder and reciprocates. Two seals are provided between the second piston and the first cylinder. Compared with the second piston which only has one seal, the sealing performance is better. Moreover, regardless of the material and wall thickness of the first cylinder, good sealing performance can be maintained. This reduces the cost of the fastening tool without affecting its performance, and the airtightness is better.

[0022] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0024] Figure 1 A perspective view of a nail gun according to one embodiment of this application;

[0025] Figure 2 This is a cross-sectional view of a fastening tool according to one embodiment of this application;

[0026] Figure 3 This is a schematic diagram showing the second piston in a second position according to one embodiment of this application;

[0027] Figure 4 This is a schematic diagram of a nail-driving motion state of an impact component according to one embodiment of this application;

[0028] Figure 5 This is a schematic diagram showing the first piston in the fourth position according to one embodiment of this application;

[0029] Figure 6 This is a schematic diagram of a reset motion state of an impact assembly according to one embodiment of this application;

[0030] Figure 7 for Figure 6 Enlarged view of a portion of the second piston at point E;

[0031] Figure 8 for Figure 7 A schematic diagram of another type of seal;

[0032] Figure 9 This is a three-dimensional view of the second piston;

[0033] Explanation of reference numerals in the attached figures:

[0034] 100-Fastening tool; 110-Housing housing; 111-Energy storage housing; 112-Tail cover; 113-Head cover; 114-Drive housing; 115-Grip housing; 116-Battery pack mating part; 120-Nose assembly; 130-Nail magazine; 140-Safety trigger lever; 150-Trigger; 151-Motor; 152-Crank-connecting rod mechanism; 153-Controller; 1530-Magnet; 1531-Sensor; 154-Second piston; 1540-First through hole; 1542, 1544-First seal; 543, 1545 - Second seal; 1546 - Inner wall surface; 1547 - Outer wall surface; 1548 - First recess; 1549 - Second recess; 155 - Second cylinder; 1551 - Air inlet; 156 - Impact assembly; 1560 - First piston; 1562 - Striking component; 1565 - Buffer block; 157 - First cylinder; 1571 - Exhaust port; 1572 - Fourth seal; 158 - Tail cap; 159 - Valve assembly; 1591 - Spring; 1592 - Third seal; 1598 - Through hole. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the implementation methods and features in the implementation methods of this application can be combined with each other.

[0036] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0038] Some embodiments of this application provide a fastening tool 100, specifically a nail gun, used to generate an impact force on a nail, thereby forcing the nail into the workpiece. For example... Figures 1-2 As shown, the fastening tool 100 includes: a housing 110, a motor 151, an impact assembly 156, a first cylinder 157, a second cylinder 155, and a second piston 154. The motor 151 is disposed within the housing 110. The impact assembly 156 includes a first piston 1560 and a striking component 1562 connected to the first piston 1560. The striking component 1562 is used to strike the fastener.

[0039] In some embodiments, the fastening tool 100 further includes a nozzle assembly 120, a safety trigger lever 140, and a trigger 150. After pressing the safety trigger lever 140 and pulling the trigger 150, the striking component 1562 strikes the fastener, which is supplied by the nail magazine 130 and ejected from the channel of the nozzle assembly 120. When the fastening tool 100 is held, the striking component 1562 moving in direction A to strike the fastener is defined as forward, moving in direction B away from the nozzle assembly 120 is defined as rearward, the direction along the extension direction generally parallel to the nail magazine 130, the direction closer to the nozzle assembly 120 is defined as upward, and the direction away from the nozzle assembly 120 is defined as downward. Furthermore, from the perspective of the operator holding the fastening tool 100, the left and right directions (vertical and forward / backward, up / down) are defined.

[0040] In some embodiments, the housing 110 includes an energy storage housing 111, a tail cover 112, a head cover 113, a drive housing 114, and a grip housing 115. The energy storage housing 111 extends in a front-rear direction, the head cover 113 is located in front of the energy storage housing 111, the drive housing 114 is substantially perpendicular to the energy storage housing 111, connects to the head cover 113 and extends in a vertical direction, and the grip housing 115 extends downward from the energy storage housing 111, is angled relative to the drive housing 114, and gradually moves away from the drive housing 114 in the downward direction, so that the drive housing 114 and the grip housing 115 are aligned. There is sufficient space between the housings 115 for gripping. The battery pack mating part 116 is located below the gripping housing 115 and connects the gripping housing 115 and the drive housing 114. The battery pack mating part 116 is used to connect the battery pack. The controller 153 is located in the housing space above the battery pack mating part 116. The tail cover 112 is located behind the energy storage housing 111 and is used to block the space at the rear of the energy storage housing 111. The blocking here only blocks the energy storage mechanism inside the energy storage housing 111, rather than sealing it. Gas can still enter the energy storage housing 111 through the tail cover 112.

[0041] The fastening tool 100 is powered by a rechargeable battery pack, such as a battery pack (not shown in the figure). The battery pack, in conjunction with a corresponding power circuit, powers the fastener driver 100. The fastening tool 100 can also be powered by other power sources, such as an AC power cord connected to mains power, or other connecting cables that can be connected to a power supply device. Mains power or other power sources, in conjunction with corresponding rectification, filtering, and voltage regulation circuits, power the corresponding components of the fastening tool 100.

[0042] In some embodiments, a first cylinder 157 and a second cylinder 155 are located within an energy storage housing 111. The first cylinder 157 has a first chamber, and a first piston 1560 is disposed within the first chamber. The second cylinder 155 is sleeved outside the first cylinder 157 and arranged parallel to it. The second cylinder 155 has a second chamber that communicates with the first chamber. A second piston 154 is disposed within the second chamber and can be driven by a motor 151 to reciprocate within the second chamber. Specifically, after the motor 151 is energized, it drives a crank-connecting rod mechanism 152 to reciprocate via a reduction mechanism. The crank-connecting rod mechanism 152 is connected to the second piston 154, driving the second piston 154 to reciprocate within the second chamber of the second cylinder 155. The second chamber is the space remaining after the first cylinder 157 is removed from the second cylinder 155.

[0043] In some embodiments, such as Figure 9As shown, the second piston 154 is generally cylindrical and has a first through hole 1540 extending through it along its axial direction. The second piston 154 has an inner wall surface 1546 surrounding the first through hole 1540 and an outer wall surface 1547 surrounded by the second cylinder 155. The first cylinder 157 is disposed through the first through hole 1540. The inner wall surface 1546 is provided with a first recess 1548 and a second recess 1549 for accommodating a seal. The second recess 1549 is located at a different position relative to the first recess 1548 along the inner wall surface 1546.

[0044] Since one side of the second piston 154 is open to the outside, and the other side of the second piston 154 forms a sealed space with the tail cap 158, and the first cylinder 157 is installed through the first through hole 1540 of the second piston 154, the inner wall surface 1546 of the second piston 154 needs to form a good seal with the first cylinder 157. However, due to the manufacturing process of the first cylinder 157, the outer surface of the first cylinder 157 is not actually a uniform outer diameter, that is, the first cylinder 157 has manufacturing tolerances. Thus, during the reciprocating motion of the second piston 154, there may be gaps between the second piston 154 and the first cylinder 157 in some positions. In this way, gas will flow between the two sides of the second piston 154, failing to achieve a complete seal. Once gas flows between the two sides of the second piston 154, the air pressure between the second piston 154 and the tail cover 158 is difficult to maintain. As the second piston 154 moves closer to the tail cover, the pressure in the sealed space between the second piston 154 and the tail cover 158 increases. Gas will more easily flow through the gap between the second piston 154 and the first cylinder 157 from the sealed space to the other side of the second piston 154. The sealed space cannot generate enough pressure, and the impact component 156 will not be able to obtain enough energy storage, and will not have enough impact force to eject the fastener.

[0045] The inner wall surface 1546 of the second piston 154 is provided with a first recess 1548 and a second recess 1549 for accommodating a sealing element. The first recess 1548 and the second recess 1549 are located at different positions on the axis of the second piston 154, thus providing two sealing structures to compensate for the inadequacy of a single seal. Optionally, the inner wall surface 1546 of the second piston 154 may have more than two recesses, i.e., more than two sealing structures, ensuring a good seal between the movable second piston 154 and the first cylinder 157, eliminating gaps for gas flow and preventing leakage.

[0046] In some embodiments, the centerline of the first through hole 1540 is offset from the centerline of the second piston 154 by less than 15.6 mm. This means the distance between the centerline of the first cylinder 157 and the centerline of the second cylinder 155 is less than 15.6 mm. Furthermore, the first through hole 1540 is offset upwards, causing the impact assembly 156 to be offset upwards relative to the second piston 154. This determines the position of the nozzle assembly 120. If the first through hole 1540 is offset downwards, the nozzle assembly 120 and the energy storage housing 111 will be significantly separated vertically. This will affect the operating space of the fastening tool 100, especially for operations on ceilings or similar structures. The energy storage housing 111, being higher than the nozzle assembly 120, will interfere with the operating space of the nozzle assembly 120, reducing the accessibility of the fastening tool.

[0047] In some embodiments, the first recess 1548 and the second recess 1549 are annular grooves, which are recessed around the inner wall surface 154 of the second piston 154 to form a complete annular groove around the axis of the first through hole 1540. This is used to embed a seal, which facilitates the installation of the seal and provides a better seal around the second piston 154. The second piston 154 is arranged around the first cylinder 157 through the seal, and while sealing, the first cylinder 157 also provides good guidance for the movement of the second piston 154.

[0048] In some embodiments, the annular groove has a rectangular cross-section and its opening faces the radial direction of the first through hole 1540.

[0049] In some embodiments, such as Figure 7 and Figure 8 As shown, a first sealing element (1542, 1544) is provided in the first recess 1548, and a second sealing element (1543, 1545) is provided in the second recess 1549. Optionally, the inner wall surface 1546 of the second piston 154 is provided with multiple recesses and multiple sealing elements to achieve better sealing.

[0050] In some embodiments, the first seal (1542, 1544) and / or the second seal (1543, 1545) are one of the following: O-rings, X-rings, Y-rings, V-rings, U-rings, and star-shaped rings. Different types of seals produce different sealing effects. Depending on the manufacturing precision of the outer surface of the first cylinder 157, different seal structures can be adaptively selected. Of course, different types of seals can also be combined to achieve different sealing requirements for the second piston 154.

[0051] In some embodiments, the first cylinder 157 is made of plastic, which reduces the manufacturing cost of the first cylinder 157. However, since the first cylinder 157 is made of plastic, the precision of the outer surface of the first cylinder 157 will be reduced, thus requiring a better sealing structure to achieve a seal.

[0052] In some embodiments, the wall thickness H of the first cylinder 157 is less than 2 mm. The first cylinder 157 can be made of metal or plastic. Since the wall thickness of the first cylinder is small, the precision of its outer surface is reduced. The smaller the wall thickness, the more likely its outer surface is to fluctuate and cause manufacturing tolerances. At this time, a good seal is required so that the inner wall surface 1546 of the second piston 154 surrounds the first cylinder 157 and the gas on both sides of the second piston 154 is not connected.

[0053] In some embodiments, the minimum distance C1 between the first recess 1548 and the second recess 1549 along the axial direction of the first through hole 1540 is at least 1 mm. When the minimum distance C1 between the first recess 1548 and the second recess 1549 along the axial direction of the first through hole 1540 is less than 1 mm, on the one hand, the first recess 1548 and the second recess 1549 are close together, making it difficult to process the recess; on the other hand, the first recess 1548 and the second recess 1549 are close together, resulting in a close sealing distance, which also makes it difficult to achieve a good sealing effect.

[0054] In some embodiments, the maximum distance C2 between the first recess 1548 and the second recess 1549 along the axial direction of the first through hole 1540 accounts for at least 15% of the length C3 of the second piston 154. The larger the maximum distance between the first recess 1548 and the second recess 1549 along the axial direction of the first through hole 1540 accounts for the length of the second piston 154, the more space the seal occupies, and the better its sealing effect.

[0055] In some embodiments, the second piston 154 is provided with either a magnet 1530 or a sensor 1531, and the other magnet 1530 or sensor 1531 is stationary relative to the housing 110. The sensor 1531 can detect the position of the magnet 1530 and thus indirectly detect the second piston 154, and control the motor to run through the controller 153. In this way, the magnet 1530 or sensor 1531 is directly installed in the space where the second piston 154 is located, so there is no need to place the magnet 1530 or sensor 1531 in other locations. The structural layout is more reasonable and the space utilization of the whole machine is improved. Moreover, since the magnet 1530 or sensor 1531 is embedded in the second piston 154, there will be no problem of falling off or being unable to be detected due to dust or other interference, making the control more precise.

[0056] In summary, by providing at least two sealing structures on the inner wall surface 1546 of the second piston 154, a good seal is formed between the second piston 154 and the outer surface of the first cylinder 157. Furthermore, a sealing structure is also provided on the outer wall surface 1547 of the second piston 154, which significantly improves the sealing performance between the second piston 154 and the inner surface of the second cylinder 155. Thus, during the movement of the second piston 154, the gas does not flow between the two sides. Even if the wall thickness of the first cylinder 157 is relatively thin or made of plastic, and the manufacturing process makes it difficult to ensure the manufacturing precision of its outer surface, a good sealing effect can still be achieved. This improves the quality of nailing while also meeting the requirement of low cost. Moreover, even after prolonged use, even if a single seal fails, the sealing effect is not affected, thus improving the overall service life of the product.

[0057] In some embodiments, the first cylinder 157 has a channel communicating with the second cylinder 155, and a valve assembly 159 is provided at the tail of the first cylinder 157. The valve assembly 159 is capable of opening and closing the channel between the second chamber and the first chamber, so that the gas between the second chamber and the first chamber is connected or not connected.

[0058] The first cylinder 157 and the second cylinder 155 are connected by the tail cap 158. Figures 2-6 A schematic diagram showing the sequential action of the first piston 1560 and the second piston 154. Figure 2 The second piston 154 is located in the third position, furthest from the tail cover 158, while the first piston 1560 is located in the first position, closest to the tail cover 158. As the crank-connecting rod mechanism 152 moves, the second piston 154 moves towards the tail cover 158, reaching... Figure 3 As shown in the fourth position near the tail cover 158, during this process, the second piston 154 contacts the valve assembly 159, opens the valve assembly 159, and opens the passage between the second chamber and the first chamber, so that the gas between the second chamber and the first chamber is connected. At this time, the gas compressed by the second piston 154 in the second cylinder 155 instantly enters the first cylinder 157, pushing the first piston 1560 to start moving away from the tail cover 158. The fourth position is defined as the position closest to the tail cover 158 after the second piston 154 pushes open the valve assembly 159.

[0059] Figure 4 As shown, the first cylinder 157 is provided with several exhaust ports 1571, and a fourth seal 1572 is provided on the outside of the exhaust ports 1571. As the second piston 154 continues to push the valve assembly 159 to move, the first piston 1560 moves to a position close to the exhaust ports 1571 and reaches... Figure 5The second position shown is after passing the exhaust port 1571. The second position is defined as the position when the first piston 1560 just contacts the buffer block 1565. Under normal circumstances, due to the action of high pressure gas, the first piston 1560 will continue to compress the buffer block 1565 after contacting the buffer block 1565 and continue to move forward a distance. When the first piston 1560 passes the exhaust port 1571, the high-pressure gas in the first cylinder 157 pushes open the fourth seal 1572 and is discharged outward from the exhaust port 1571. Subsequently, the crank-connecting rod mechanism 152 pulls the second piston 154 to move away from the tail cover 158. Under the action of the spring 1591, the valve assembly 159 returns to the state of closing the passage between the second chamber and the first chamber. A negative pressure is formed between the second piston 154 and the tail cover 158. Due to the pressure difference between the first cylinder 157 and the second cylinder 155, the gas in the first cylinder 157 flows into the second cylinder 155 through the through hole 1598 on the valve assembly 159, pushing open the third seal 1592 on the valve assembly 159. Figure 6 As shown, the first piston 1560 is pulled to move closer to the tail cap 158, thus completing the reset of the first piston 1560.

[0060] The second cylinder 155 is provided with an air inlet 1551. When the second piston 154 moves away from the tail cover 158 and passes the air inlet 1551, external gas can enter the second cylinder 155 through the air inlet 1551. Then, as the crank connecting rod mechanism 152 drives the second piston 154 to move closer to the tail cover 158, it enters the next nailing cycle.

[0061] As can be seen, in one nailing cycle, the second piston 154 reciprocates between the two extreme positions of the third and fourth positions in the second chamber, and the first piston 1560 reciprocates between the two extreme positions of the first and second positions in the first chamber. As the second piston 154 moves from the third position to the fourth position, it generates high-pressure gas, which pushes the first piston 1560 from the first position to the second position, thus realizing nailing. As the second piston 154 moves from the fourth position to the third position, it generates negative pressure, which drives the first piston 1560 from the second position back to the first position, thus completing the reset of the first piston 1560, which completes one nailing cycle.

[0062] Optionally, the second piston 154 is provided with either a magnet 1530 or a sensor 1531. The magnet 1530 or sensor 1531 moves synchronously with the movement of the second piston 154, while the other magnet 1530 or sensor 1531 is stationary relative to the housing 110. The sensor 1531 can detect the magnet 1530 and transmit the detection signal to the controller 153. By checking the signal, the position of the second piston 154 is identified, thereby the controller 153 controls the operation of the motor 151, for example, by braking the motor 151 or by allowing it to run continuously without braking.

[0063] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A fastening tool, characterized in that, include: case; The motor is housed within the casing; An impact assembly, the impact assembly including a first piston and a striking component connected to the first piston, the striking component being used to strike a fastener; The first cylinder has a first chamber, and the first piston is disposed in the first chamber; The second cylinder is fitted outside the first cylinder and forms a second chamber that can communicate with the first chamber; The second piston is disposed in the second chamber and is driven by the motor to reciprocate in the second chamber. The second piston is provided with a first through hole and has an inner wall surface surrounding the first through hole and an outer wall surface surrounded by the second cylinder. The first cylinder is disposed through the first through hole. The inner wall surface is provided with a first recess and a second recess for accommodating a seal, the second recess being located at a different position relative to the first recess along the inner wall surface.

2. The fastening tool according to claim 1, characterized in that, The first recess and the second recess are annular grooves.

3. The fastening tool according to claim 2, characterized in that, The annular groove has a rectangular cross-section, and its opening faces the radial direction of the first through hole.

4. The fastening tool according to claim 1, characterized in that, A first sealing element is provided in the first recess, and a second sealing element is provided in the second recess.

5. The fastening tool according to claim 4, characterized in that, The first seal and / or the second seal is one of an O-ring, X-ring, Y-ring, V-ring, or U-ring.

6. The fastening tool according to claim 1, characterized in that, The first cylinder is made of plastic.

7. The fastening tool according to claim 1, characterized in that, The wall thickness of the first cylinder is less than 2mm.

8. The fastening tool according to claim 1, characterized in that, The minimum distance between the first recess and the second recess along the axial direction of the first through hole is at least 1 mm.

9. The fastening tool according to claim 1, characterized in that, The maximum distance between the first recess and the second recess along the axial direction of the first through hole is at least 15% of the length of the second piston.

10. The fastening tool according to claim 1, characterized in that, The second piston is provided with either a magnet or a sensor, and the other of the magnet or the sensor is stationary relative to the housing.

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