An electric nailing tool

Abstract

This invention relates to an electric nailing tool, belonging to the field of power tool technology. An electric nailing tool includes a housing with a handle, an energy storage mechanism consisting of a cylinder and a piston housed within the housing, a nailing seat at the front end of the housing with a retractable striking arm forming an striking mechanism, a nailing mechanism consisting of a striking pin extending from the piston to the nailing seat, a lifting mechanism consisting of a motor-driven drive wheel meshing with the striking pin, a nail feeding mechanism mounted on the side of the nailing seat, and a power transmission mechanism consisting of a gearbox and a motor located between the handle and the nail feeding mechanism. Its advantages are: the drive wheel is quickly ejected at the engagement critical point to avoid stress damage to the striking pin teeth; it avoids interference between the excessively high speed of the drive wheel and the lifting teeth, thus improving the overall lifespan of the electric nailing tool.

Description

Technical Field

[0001] This invention relates to an electric nailing tool, belonging to the field of power tool technology. Background Technology

[0002] Fastener driving tools such as nail guns are typically used to drive fasteners like nails into workpieces, connecting two or more workpieces. These power fastener driving tools utilize compressed air, electrical energy, or the elastic potential energy of elastic elements as power sources. Their basic structure includes a handle, a drive energy source, a control unit, and a nail magazine. For tools using compressed air as a power source, there is usually a cylinder with a built-in piston for compressing air. A firing pin is mounted on the piston to release the air energy and strike the nail. A lifting mechanism engages with the lifting teeth on the firing pin to raise it to a high-energy position. During the lifting process, the force between the lifting mechanism and the lifting teeth increases, especially near the high-energy position, where the contact point between the lifting mechanism and the tip of the firing pin's lifting teeth experiences extremely high stress in a short period. This can damage the tip of the firing pin's lifting teeth and the lifting mechanism, thus reducing the overall lifespan of the machine. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing an electric nailing tool that avoids damage to parts caused by instantaneous extreme stress, thereby protecting tool components and creating more favorable conditions for extending service life.

[0004] This invention solves the technical problem through the following technical solution: an electric nailing tool, comprising a housing with a handle, an energy storage mechanism consisting of a cylinder and a piston housed within the housing, a nailing seat located at the front end of the housing with a retractable striking arm forming an striking mechanism, a nailing mechanism consisting of a striking pin connected to the piston and extending to the nailing seat, a lifting mechanism consisting of a motor-driven drive wheel meshing with the striking pin, a nail feeding mechanism mounted on the side of the nailing seat, and a power transmission mechanism consisting of a gearbox and a motor located between the handle and the nail feeding mechanism. The gearbox contains a gear set driven by the motor, the gear set is connected to a drive shaft and transmits power to a drive wheel on the shaft, the drive wheel engages and links with the striking pin of the nailing seat, a clutch is provided at the connection between the gear set and the drive shaft, the surface of the clutch is provided with a clearance surface for relative rotation of the drive shaft and the clutch, and a locking device is provided on the drive shaft located at the upper end of the clutch to restrict the speed of the drive shaft. The locking device engages with the drive shaft to limit the speed of the drive shaft when the speed of the drive shaft is greater than that of the clutch.

[0005] Furthermore, the locking device consists of a locking ring fixedly sleeved on the outer periphery of the drive shaft and locking pins evenly distributed between the locking ring and the drive wheel.

[0006] The drive wheel is evenly distributed with drive pins that engage with and cooperate with the lifting tooth movement of the striker.

[0007] The lifting tooth and the drive pin have an engagement position, an engagement critical position, and a position beyond the engagement critical position.

[0008] When the lifting tooth and the drive pin are in the meshing position, the clutch and the drive shaft are engaged at the same speed. The drive wheel drives the striker to move from a low-energy position to the point where the drive pin meshes with the last lifting tooth. The contact surface between the drive pin and the last lifting tooth is the meshing surface, and the point of final contact is the critical point.

[0009] When the lifting tooth and the drive pin are at the critical engagement position, the clutch drives the drive shaft to continue rotating the drive wheel, and the drive pin and the tip of the lifting tooth engage in line contact, and the stress at the engagement point reaches its peak.

[0010] When the lifting tooth and the drive pin are at the critical engagement position, the stress at the engagement point forces the lifting tooth to generate a thrust on the drive pin in the direction of drive wheel rotation. The drive shaft is under force and, under the action of the clearance surface, its speed changes with the clutch, resulting in relative rotation. When the drive wheel reaches the critical point, it instantly gains speed and drives the drive pin to pass the critical point position.

[0011] When the drive pin passes the critical point, the speed of the drive wheel decreases, the clutch and drive shaft engage at the same speed, the lifting teeth of the striker disengage from the drive pin, and the striker moves towards a lower energy position until it engages with the first drive pin on the drive wheel. When passing the critical point, the speed of the drive wheel will be greater than that of the clutch. The higher the energy of the energy storage mechanism, the greater the thrust of the striker lifting teeth on the drive wheel, and the greater the speed of the drive wheel. The drive wheel may also push the clutch through the drive shaft to increase its speed, causing the drive wheel to return to the initial engagement point before the striker reaches the lower energy position, resulting in interference between the drive pin and the lifting teeth. At this time, the drive shaft speed briefly exceeds that of the clutch, the drive shaft contacts the locking pin and presses it against the locking ring. The locking ring is fixed in the gearbox and cannot move, using the self-locking angle to brake the drive shaft, achieving the braking function. In this way, the surface of the drive shaft will not touch the surface of the clutch, avoiding the problem of excessively high drive wheel speed and interference with the lifting teeth.

[0012] The locking device has the function of locking itself when the firing pin is in a stopped position under the pressure of the energy storage mechanism, and it engages with the drive shaft to prevent the drive shaft from rotating, thus achieving a self-locking function.

[0013] The drive shaft has a driving surface, a braking surface that contacts the locking device, and a self-locking surface, all of which are the same surface. This simplifies the structure, allowing the drive shaft to perform braking, driving, and self-locking functions through a single surface.

[0014] During nailing operations, the gearbox transmits motion to the drive wheel of the lifting mechanism via the clutch. The drive wheel engages with the lifting teeth of the impact pin via the drive pin, raising the impact pin from a low-energy position to a high-energy position. When the last tooth is engaged, due to the large energy accumulation, the force between the lifting teeth and the drive pin is also significant, especially at the critical point of tooth tip engagement, where the drive pin contacts the lifting tooth line, resulting in extremely high stress. The clutch of this invention is designed with a clearance surface, allowing the drive wheel to instantaneously rotate faster than the clutch within a small angle. When the engagement reaches the critical point, the tooth tip instantly kicks the drive wheel away from the critical point, thus preventing stress damage to parts and extending tool life. This invention also simplifies the structure, integrating the functions of preventing kicking out due to extreme stress at the critical point, preventing overspeeding of the drive wheel and interference with the impact pin lifting teeth, and the gearbox's reverse self-locking function. For example, the drive surface, braking surface, and self-locking surface of the drive shaft are all the same surface. Its beneficial effects are: avoiding the problem of excessively high drive wheel speed and interference with the lifting teeth, and improving the overall lifespan of the electric nailing tool. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a structure according to an embodiment of the present invention.

[0016] Figure 2 for Figure 1 A schematic diagram of the internal three-dimensional structure.

[0017] Figure 3 for Figure 1 Schematic diagram of the clutch section.

[0018] Figure 4 This is a cross-sectional view of the drive wheel structure before it reaches the critical point.

[0019] Figure 5 This is a schematic diagram of the cross-sectional structure of the clutch before it reaches the critical point.

[0020] Figure 6 This is a cross-sectional view of the drive wheel structure after it reaches the critical point.

[0021] Figure 7 This is a schematic diagram of the cross-sectional structure of the clutch after it reaches the critical point.

[0022] Figure 8 This is a schematic diagram of the cross-sectional structure of the drive wheel when it is at the critical point.

[0023] Figure 9 This is a schematic diagram of the cross-sectional structure of the clutch when it is at the critical point.

[0024] Figure 10 This is a cross-sectional view of the drive wheel at the moment of ejection at the critical point.

[0025] Figure 11This is a schematic cross-sectional view of the clutch at the moment of disengagement at the critical point.

[0026] Figure 12 for Figure 1 A cross-sectional view of the drive wheel in the clutch-locked state.

[0027] Figure 13 for Figure 1 A cross-sectional view of the clutch in the clutch-locked state. Detailed Implementation Example

[0028] The general structure of this embodiment is as follows: Figure 1 , Figure 2 As shown, the housing 1 with a handle houses an energy storage mechanism 2 consisting of a cylinder and a piston, an impact mechanism 3 consisting of a retractable impact arm consisting of a front-end nail-driving seat, a nail-driving mechanism 4 consisting of a firing pin that extends from the piston to the impact arm, a lifting mechanism consisting of a drive wheel 5 that meshes with the firing pin and is driven by a gearbox, a nail-feeding mechanism 6 installed on the side of the nail-driving seat, and a power transmission mechanism consisting of a gearbox 7 and a motor 8 located between the handle and the nail-feeding mechanism.

[0029] like Figure 3 Reference shown Figure 4 Figure 5 The gearbox 7 contains a gear set 7.5, which transmits the speed and torque of the motor 8 to the clutch 7.1. The clutch 7.1, through the engagement of face 7.1-1 and face 7.4-2 of the drive shaft 7.4, transmits the speed and torque to the drive shaft 7.4. The drive shaft and clutch are rotatably mounted inside the gearbox 7. The drive wheel 5 is mounted on the drive shaft 7.4, and through the engagement of face 5-1 and face 7.4-1 of the drive wheel, the movement of the drive wheel is always consistent with that of the drive shaft. The drive pin 5.1 is rotatably mounted in the hole 5-2 of the drive wheel 5; the drive wheel 5 rotates with the drive pin 5.1, and the drive pin 5.1 meshes with the lifting teeth 4-1 of the striker 4, converting the speed and torque of the motion into the linear motion speed of the striker 4.

[0030] Drive wheel 5 raises firing pin 4 from a low-energy position to a high-energy position, such as Figure 4 As shown, before the engagement of the drive pin 5.1 and the lifting tooth 4-1 reaches the critical point, the drive pin 5.1 is engaged with the engagement surface 4-2 of the lifting tooth. As the striker is lifted, the required force is greater, especially when the last lifting tooth 4-1 and the drive pin 5.1 are engaged.

[0031] like Figure 8 As shown, when the last lifting tooth 4-1 and the drive pin 5.1 mesh to the critical point, the drive pin 5.1 meshes with the tip side 4-3 of the lifting tooth 4-1 in a line contact manner, and the stress acting on the meshing line is extremely high. Figure 9As shown, at this time, the clutch 7.1 pushes the drive shaft 7.4's surface 7.4-2 to rotate through surface 7.1-1, thereby continuing to drive the drive wheel 5 to rotate;

[0032] like Figure 10 As shown, after the meshing reaches the critical point, due to the extreme stress at the meshing point, the lifting tooth 4-1 exerts a huge thrust on the drive pin 5.1, and the thrust is directed in the direction of the drive wheel's rotation. Figure 11 As shown, the clutch 7.1 is designed with a clearance surface 7.1-2, which allows the drive shaft and the clutch to rotate relative to each other within a certain range. This results in very little resistance to the drive wheel in the direction of rotation, so that the drive wheel can obtain a large speed at the moment it reaches the critical point. The drive pin can quickly pass through the critical point position, avoiding the generation of ultimate stress at the meshing point and protecting the parts.

[0033] like Figure 6 Figure 7 As shown, after the engagement crosses the critical point, the speed of the drive wheel decreases, and the clutch face 7.1-1 re-engages with the drive shaft face 7.4-2, bringing the drive wheel speed back into sync with the clutch. After crossing the critical point, the ejector pin's lifting teeth disengage from the drive pin and cease engagement. Under the energy released by the energy storage mechanism, the ejector pin moves to a lower energy position, while the drive wheel continues to rotate under the clutch's influence. Once the ejector pin reaches the lower energy position, the first drive pin on the drive wheel moves to the initial engagement position, and the drive pin begins to engage with the ejector pin's lifting teeth, lifting the ejector pin to a higher energy position.

[0034] When crossing the critical point, the speed of the drive wheel will exceed that of the clutch. The higher the energy of the energy storage mechanism, the greater the thrust of the striker lifting teeth on the drive wheel, and the greater the speed of the drive wheel. The drive wheel may also increase its speed by pushing the clutch surface 7.1-2 through the drive shaft surface 7.4-2, causing the drive wheel to return to the initial engagement point before the striker reaches a low-energy position, resulting in interference between the drive pin and the lifting teeth. The clutch structure of this embodiment avoids this problem. Figure 11 As shown, when the drive shaft speed exceeds that of the clutch for a short time, the drive shaft face 7.4-2 contacts the locking pin 7.2 and presses it against the locking ring face 7.3-1. The locking ring 7.3 is fixed in the gearbox and cannot move. The self-locking angle is used to brake the drive shaft. In this way, the drive shaft face 7.4-2 will not touch the clutch face 7.1-2, which can avoid the problem of excessive speed of the drive wheel and interference with the lifting gear.

[0035] After a nail-driving operation, the firing pin typically stops at a position between the high-energy and low-energy positions. When the firing pin is in the stopped position, it is under pressure from the energy storage mechanism, such as... Figure 12 As shown, the lifting tooth 4-1 of the firing pin pushes the driving pin 5.1 in the opposite direction via surface 4-2; as Figure 13As shown, at this time, the drive shaft face 7.4-2 and the clutch faces 7.1-1 and 7.1-2 are not mated. The drive shaft face 7.4-2 contacts the locking pin 7.2 and presses it against the locking ring face 7.3-1. The locking ring 7.3 is fixed in the gearbox and cannot move. The self-locking angle is used to brake the drive shaft, realizing the reverse self-locking function of the gearbox, thereby enabling the drive pin to support the lifting teeth of the striker and ensure that the striker is stable in the stop position.

[0036] In this embodiment, the kick-out function to prevent ultimate stress when sliding past the critical point, the braking function to prevent overspeed of the drive wheel and interference between the impact pin lifting tooth, and the reverse self-locking function of the gearbox are all integrated together. For example, the drive surface, braking surface and self-locking surface of the drive shaft are all the same surface, which simplifies the structure.

[0037] In addition to the above-described embodiments, the present invention may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. An electric nailing tool, comprising a housing with a handle, an energy storage mechanism consisting of a cylinder and a piston housed within the housing, a nailing seat located at the front end of the housing with a retractable striking arm forming an striking mechanism, a nailing mechanism consisting of a striking pin connected to the piston and extending to the nailing seat, a lifting mechanism consisting of a motor-driven drive wheel meshing with the striking pin, a nail feeding mechanism mounted on the side of the nailing seat, and a power transmission mechanism consisting of a gearbox and a motor located between the handle and the nail feeding mechanism, characterized in that: The gearbox contains a gear set driven by a motor. The gear set is connected to a drive shaft and transmits power to a drive wheel on the shaft. The drive wheel engages with the striker of the nail holder. A clutch is provided at the connection between the gear set and the drive shaft. The surface of the clutch is provided with a clearance surface for relative rotation between the drive shaft and the clutch. A locking device for limiting the speed of the drive shaft is provided on the drive shaft located at the upper end of the clutch.

2. The electric nail-driving tool according to claim 1, characterized in that: The locking device has the function of engaging with the drive shaft to limit the speed of the drive shaft when the speed of the drive shaft is greater than that of the clutch; the locking device consists of a locking ring fixedly sleeved on the outer periphery of the drive shaft and locking pins evenly distributed between the locking ring and the drive wheel.

3. The electric nailing tool according to claim 1, characterized in that: The drive wheel is evenly distributed with drive pins that engage with and cooperate with the lifting tooth movement of the striker.

4. The electric nail-driving tool according to claim 3, characterized in that: The lifting tooth and the drive pin have an engagement position, an engagement critical position, and a position beyond the engagement critical position.

5. The electric nail-driving tool according to claim 4, characterized in that: When the lifting tooth and the drive pin are in the meshing position, the clutch and the drive shaft are engaged at the same speed. The drive wheel drives the striker to move from a low-energy position to the point where the drive pin meshes with the last lifting tooth. The contact surface between the drive pin and the last lifting tooth is the meshing surface, and the point of final contact is the critical point.

6. The electric nail-driving tool according to claim 4, characterized in that: When the lifting tooth and the drive pin are at the critical engagement position, the clutch drives the drive shaft to continue rotating the drive wheel, and the drive pin and the tip of the lifting tooth engage in line contact, and the stress at the engagement point reaches its peak.

7. The electric nailing tool according to claim 4, characterized in that: When the lifting tooth and the drive pin are at the critical engagement position, the stress at the engagement point forces the lifting tooth to generate a thrust on the drive pin in the direction of drive wheel rotation. The drive shaft is under force and, under the action of the clearance surface, its speed changes with the clutch, resulting in relative rotation. When the drive wheel reaches the critical point, it instantly gains speed and drives the drive pin to pass the critical point position.

8. The electric nailing tool according to claim 7, characterized in that: After the drive pin passes the critical point, the speed of the drive wheel decreases, the clutch engages with the drive shaft at the same speed, the lifting teeth of the striker disengage from the drive pin, and the striker moves to a low-energy position until it engages with the first drive pin on the drive wheel.

9. The electric nailing tool according to claim 1, characterized in that: The locking device is designed to engage with the drive shaft to prevent rotation of the drive shaft when the firing pin is in a stopped position under pressure from the energy storage mechanism.

10. The electric nailing tool according to claim 1, characterized in that: The drive shaft has a drive surface, a braking surface that contacts the locking device, and a self-locking surface, wherein the drive surface, braking surface, and self-locking surface are the same surface.

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