Driving tool

Abstract

To provide a gas spring-type driving tool, which is configured so as to improve impact absorbability and durability of a cushion by increasing volumes of the cushion that contacts a piston.SOLUTION: A driving tool 1 comprises: a cylinder 12; a piston 14 that is moved in the cylinder 12 by gas pressure; a driver main body 15 that moves together with the piston 14 to strike a driving tool N; and a plurality of driver protruding parts 16 protruding, along a side edge of the driver main body 15, in a width direction from the driver main body 15. The driving tool 1 has a lift mechanism 20 that comprises a plurality of engagement parts 24 that engage with the plurality of driver protruding parts 16 and rotates to return the driver main body 15 to an initial position, and a cylindrical cushion 18 provided with an insertion hole 18a through which the driver main body 15 is inserted, which receives impact of the piston 14. The driver main body 15 is arranged so that a width center line K of the driver main body 15 is offset in a direction in which the line separates from the lift mechanism 20 more than a width center line L of the piston 14.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a driving tool for driving driving tools such as nails and staples into wood or the like.

Background Art

[0002] Patent Document 1 discloses a gas spring type driving tool that uses the thrust of compressed gas as a striking force. The gas spring type driving tool has a piston that moves up and down in the cylinder in the driving direction, and a driver body that extends downward from the piston. The piston and the driver body both move downward in the driving direction by the gas pressure in the accumulator chamber. The driver strikes a driving tool loaded in the lower driving passage. As a result, the driving tool is injected into a material to be driven such as wood.

[0003] The gas spring type driving tool has a lift mechanism that moves the piston and the driver body upward from the lower end to the initial position and the upper end. The driver body has a plurality of driver protrusions (rack teeth) formed side by side in the vertical direction. The lift mechanism has a wheel provided with a plurality of engaging portions (pins) that engage with the plurality of driver protrusions. The plurality of engaging portions are arranged along the outer circumference of the wheel. The wheel rotates by a driving source such as an electric motor. After injecting the driving tool, the engaging portion that rotates around the wheel axis together with the wheel is engaged with the driver protrusion. The driver protrusions are sequentially engaged with the engaging portions starting from the upper driver protrusion. As a result, the driver and the piston move upward in the reverse driving direction. When the piston moves upward in the reverse driving direction, the gas pressure in the accumulator chamber is increased. When the driver is moved upward to the upper end, the engagement state between the lowermost driver protrusion and the engaging portion of the lift mechanism is released. As a result, the driving operation of the driver is performed again.

[0004] Multiple driver protrusions project from the driver body toward the lift mechanism. The center of the driver body's width in the left-right direction is coaxial with the piston's axis. Therefore, the left-right distance from the tip of the driver protrusion to the piston's axis is longer than the left-right distance from the end face of the driver body on the side opposite the lift mechanism to the piston's axis.

[0005] A cushion is provided at the lower end of the cylinder to absorb the impact of the piston moving to its lower end. The cushion is formed in a substantially cylindrical shape centered on the piston's axis so as to contact the piston's lower surface evenly. Therefore, the volume of the cushion is evenly distributed on both sides with respect to the piston's axis. A through-hole is provided in the center of the cushion, penetrating vertically to allow the driver body and driver projection to pass through. The through-hole must have a diameter that does not come into contact with at least the driver body or driver projection. Therefore, the diameter of the through-hole is set based on the distance from the tip of the driver projection to the piston's axis in the left-right direction. Increasing the volume of the cushion while maintaining the diameter of the through-hole would require increasing the size of the product. Therefore, there was a constraint on increasing the volume of the cushion that contacts the piston's lower surface. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 6915682 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, in gas spring type driving tools, it is necessary to improve the shock absorption and durability of the cushion by increasing the volume of the cushion that contacts the piston. [Means for solving the problem]

[0008] According to one feature of this disclosure, the driving tool has a cylinder and a piston that moves within the cylinder by gas pressure. The driving tool has a driver body that moves with the piston to strike the driving tool. The driving tool has a plurality of driver protrusions that project in the width direction from the driver body along the side edge of the driver body. The driving tool has a lift mechanism that has a plurality of engaging parts that engage with the plurality of driver protrusions and rotates to return the driver body to its initial position. The driving tool has a through hole through which the driver body is inserted and a cylindrical cushion that receives the impact of the piston. The driver body is positioned such that the width centerline of the driver body is offset from the width centerline of the piston in a direction away from the lift mechanism.

[0009] Therefore, the distance from the tip of the driver projection to the center line of the piston's width can be shortened by the amount of the offset between the center lines of the driver body and the center lines of the piston. This allows for a smaller opening area for the through-hole in the cushion that allows the driver body and the driver projection to pass through. This increases the volume of the cushion that contacts the bottom surface of the piston. This improves the shock absorption of the cushion. It also improves the durability of the cushion and piston that come into contact with each other. [Brief explanation of the drawing]

[0010] [Figure 1] This is a longitudinal cross-sectional view showing the piston and driver of the driving tool according to this embodiment in their initial positions. [Figure 2] This is a longitudinal cross-sectional view showing the state in which the piston and driver of the driving tool according to this embodiment are positioned at the lower moving end. [Figure 3] Figure 1 shows a cross-sectional view taken along line III-III. [Figure 4] Figure 2 shows a cross-sectional view taken along the line IV-IV. [Figure 5] Figure 1 shows a cross-sectional view taken along line VV. [Figure 6] This is a driver's perspective. [Figure 7] This is a front view of the driver. [Figure 8] Figure 7 shows a cross-sectional view taken along the line VIII-VIII. [Modes for carrying out the invention]

[0011] According to other features of this disclosure, the driver body is rotatably connected to the piston in the width direction. Therefore, the driver body can rotate in the width direction within a predetermined angular range around the connection point with the piston. Thus, even if the driver body and the driver guide that guides the driver body can slide against each other, the driver body can rotate in the width direction to quickly avoid sliding against the driver guide. This prevents unintended forces from being applied to the driver body and reduces wear on the driver body.

[0012] According to other features of this disclosure, the rotation center of the driver body relative to the piston is located on the width centerline of the piston. Therefore, the driver body has a substantially uniform amplitude of swing in the width direction relative to the width centerline of the piston. The cushions are arranged substantially evenly around the width centerline of the piston in order to contact the lower surface of the piston evenly. Therefore, the driver body can rotate substantially evenly in the width direction with respect to the width center of the cushion. This prevents the driver body or the driver projection from unintentionally contacting the inner surface of the through hole in the cushion when the driver body rotates in the width direction.

[0013] According to other features of this disclosure, the driving tool has a driver guide that guides the driver body at its end in the driving direction. The driver guide is positioned such that its width centerline is offset away from the lift mechanism from the width centerline of the piston. Thus the driver body moves in the driving direction such that its width centerline lies on the width centerline of the driver guide. The driving tool is supplied on the width centerline of the driver guide. As a result, the driver body can strike approximately the center of the driving tool in the width direction. This allows the driving tool to be ejected straight in the driving direction.

[0014] According to other features of this disclosure, the inner circumferential surface of the through-hole in the cushion is circular when viewed from the direction of movement of the driver body. Therefore, the piston and the cushion come into contact substantially evenly in the circumferential direction. As a result, the cushion deforms substantially evenly in the circumferential direction when subjected to impact from the piston. This suppresses wear on specific parts of the cushion and improves the durability of the cushion. It also suppresses unintentional tilting of the piston when it comes into contact with the cushion. This suppresses wear on the piston and cylinder.

[0015] According to other features of this disclosure, the lift mechanism has a wheel rotatably supported on a tool body and a plurality of engaging parts arranged along the circumferential direction of the wheel. At least one of the plurality of engaging parts is movable radially relative to the wheel.

[0016] Therefore, the widthwise protrusion length of the driver projection needs to be made longer by the amount of movement of the engaging portion, which is movable in the radial direction of the wheel. By positioning the width centerline of the driver body to be offset away from the width centerline of the piston from the lift mechanism, the reduction in cushion volume can be suppressed even when the protrusion length of the driver projection is made longer. In addition, the engaging portion can be brought closer to the width centerline of the piston by the amount of the offset between the width centerlines of the driver body and the width centerlines of the piston. As a result, the force with which the engaging portion pushes the bottom of the driver projection upward acts near the width centerline of the piston. This allows the driver and piston to move straight upward.

[0017] According to other features of this disclosure, the driver body has first protrusions on both sides in the width direction that project in the direction of movement of the driver body and in the height direction intersecting the width direction. Therefore, the driver body is guided by the first protrusions provided on both sides in the width direction and moves straight in the driving direction. This increases the stability with which the driver body strikes the driving tool in the driving direction.

[0018] According to another feature of the present disclosure, the driver body has a second convex portion that protrudes in the height direction at the center in the width direction, and the protruding height of the second convex portion is lower than that of the first convex portion. Therefore, by suppressing the protruding height of the second convex portion, the driver body can be provided in a lightweight manner. Further, the driver body strikes the driving tool at the lower end of the second convex portion. Therefore, by providing the second convex portion with a predetermined protruding height, the driving tool struck by the driver body can be injected with good stability.

[0019] Next, one example of an embodiment of the present disclosure will be described based on FIGS. 1 to 8. As an example of the driving tool 1, a gas spring type driving tool that uses the gas pressure in the accumulator chamber above the cylinder as a thrust force for driving the driving tool N is shown. In the following description, the driving direction of the driving tool N is downward, and the reverse driving direction is upward. The user of the driving tool 1 is generally located on the left side of the driving tool 1 in FIG. 1. The front side of the user is the rear direction (user side), and the back side opposite to the front side is the front direction. The left and right directions are based on the user.

[0020] [[ID=۷]] As shown in FIGS. 1 and 3, the driving tool 1 has a tool body 10. The tool body 10 has a configuration in which a cylinder 12 is housed in a generally cylindrical body housing 11. A piston 14 is housed in the cylinder 12 so as to be reciprocable vertically. The upper part of the cylinder 12 above the piston 14 communicates with the accumulator chamber 13. Compressed gas such as air is enclosed in the accumulator chamber 13. The gas pressure in the accumulator chamber ​​13 acts on the upper surface of the piston 14 to generate a thrust force that moves the piston 14 downward.

[0021] As shown in FIGS. 3 and 4, the lower part of the cylinder 12 communicates with a driving passage 2a of a driving nose portion ​​2 provided at the lower part of the tool body 10. The driving nose portion ​​2 is coupled to a magazine 9 loaded with a large number of driving tools N (see FIG. 1). In the driving passage 2a, the driving tools N are supplied from the magazine 9 in a posture extending vertically one by one. A contact arm 3 that can slide vertically is provided at the lower part of the driving nose portion ​​2. The contact arm 3 moves upward as shown by the virtual line in FIG. 4 by contacting the material to be driven W.

[0022] As shown in Figure 3, a vertically elongated driver 30 is connected to the lower surface of the piston 14. The lower part of the driver 30 enters the driving passage 2a. The driver 30 moves downward within the driving passage 2a due to the gas pressure of the accumulator chamber 13 acting on the upper surface of the piston 14. The downward-moving driver 30 strikes a single driving tool N supplied into the driving passage 2a. The struck driving tool N is ejected from the injection port 2c which opens at the lower end of the driving passage 2a. The ejected driving tool N is driven into the material W to be driven.

[0023] As shown in Figures 1 and 2, a grip 4 for the user to hold is provided at the rear of the tool body 10. A trigger 5, operated by the user pulling it with their fingertips, is provided on the front lower surface of the grip 4. The trigger 5 is activated by pressing the contact arm 3 against the material to be driven W and moving it upward relative to the driving nose portion 2. The grip 4 is provided with a trigger switch 5a that can be switched on or off by pulling the trigger. A battery mounting section 6 is provided at the rear of the grip 4. A battery pack 7 can be detachably attached to the rear surface of the battery mounting section 6. The battery pack 7 can be removed from the battery mounting section 6 and repeatedly charged with a separately prepared charger for use. The battery pack 7 can be used as a power source for other power tools. The battery pack 7 operates as a power source that supplies power to the electric motor 26, which will be described later.

[0024] As shown in Figures 1 and 2, the grip 4 houses a controller 8 that primarily controls the drive of the electric motor 26. The controller 8 is formed by housing a circuit board in a rectangular box-shaped case. The controller 8 is housed in the grip 4 in front of the battery mounting section 6, with its thickness direction (shortest side direction) aligned with the front-to-back direction.

[0025] As shown in Figures 3 and 4, a lift mechanism 20 is connected to the right side of the driving nose section 2. The lift mechanism 20 returns the piston 14 and driver 30 upward after the driving tool N strikes. The upward return of the piston 14 by the lift mechanism 20 increases the gas pressure in the accumulator chamber 13.

[0026] As shown in Figure 5, an electric motor 26 and a reduction gear train 27 for operating the lift mechanism 20 are arranged side by side at the rear of the lift mechanism 20. The electric motor 26, the reduction gear train 27, and the lift mechanism 20 are housed in a substantially cylindrical drive unit case 11a. The drive unit case 11a connects the lower part of the main body housing 11 and the lower part of the battery mounting section 6 (see Figure 1). The drive unit case 11a is provided integrally with the main body housing 11.

[0027] As shown in Figure 5, the electric motor 26 is housed with the motor axis J of the output shaft 26a aligned in the front-rear direction (the direction perpendicular to the driving direction perpendicular to the plane of the paper in Figure 5). A rotor 26c is provided around the output shaft 26a, integrally connected to the output shaft 26a. A stator 26b is provided radially outward from the rotor 26c, and is non-rotatably supported by the drive unit case 11a. The output shaft 26a of the electric motor 26 is rotatably supported by the drive unit case 11a via bearings 26d and 26e. The electric motor 26 is started by pulling the trigger 5, using power from the battery pack 7.

[0028] As shown in Figure 5, the front of the output shaft 26a is connected to the reduction gear train 27. The reduction gear train 27 is supported on the inner circumference side of a substantially cylindrical gear train case 28 housed in the drive unit case 11a. The reduction gear train 27 uses a three-row planetary gear train. The three rows of planetary gear trains are coaxial with each other and arranged coaxially with the motor axis J. The rotational output of the electric motor 26 is reduced by the reduction gear train 27 and output to the lift mechanism 20 at the front.

[0029] As shown in Figure 5, the lift mechanism 20 has a shaft member 21 connected to a reduction gear train 27 and a wheel 22 supported by the shaft member 21. The lift mechanism 20 is housed in a substantially cylindrical mechanism case 25 provided within the drive unit case 11a. The rotation axis of the shaft member 21 coincides with the motor axis J. The front of the mechanism case 25 is closed by a cover portion 25a. The front end of the shaft member 21 is rotatably supported by a bearing 21a mounted on the inner surface of the cover portion 25a. The rear end of the shaft member 21, the connecting portion 21b, is integrally connected to the final stage carrier 27a of the reduction gear train 27. The carrier 27a is rotatably supported by the mechanism case 25 via a bearing 27b provided on its outer circumference. When the electric motor 26 is started, the shaft member 21 and wheel 22 of the lift mechanism 20 rotate together in a counterclockwise direction in Figure 3.

[0030] As shown in Figures 3-5, a support portion 21c for supporting the wheel 22 is provided at the center of the shaft member 21 in the front-rear direction. The support portion 21c is generally cylindrical, but has a pair of bifurcated support planes 21d that extend radially and are parallel to each other. The support portion 21c has a spring housing portion 21e at an intermediate position between the pair of support planes 21d. The spring housing portion 21e is recessed along the extending direction of the pair of support planes 21d. A compression spring 23 for biasing the wheel 22 in the radial direction is housed in the spring housing portion 21e.

[0031] As shown in Figures 3 and 4, a mounting hole 22f into which the support portion 21c can be inserted is provided in the center of the wheel 22. A pair of sliding surfaces 22e that extend radially and are parallel to each other are provided on the inner wall surface of the mounting hole 22f. The distance between the pair of sliding surfaces 22e is approximately the same as the distance between the pair of support planes 21d provided on the support portion 21c. By inserting the support portion 21c into the mounting hole 22f, each sliding surface 22e and each support plane 21d come into contact with each other. As the sliding surfaces 22e slide against the support planes 21d, the wheel 22 moves radially within a certain range relative to the shaft member 21.

[0032] The wheel 22 shown in Figures 3 and 4 is in its initial position, with its center 22c located on the motor axis J, which is the rotation axis of the shaft member 21. The wheel 22 is biased toward the initial position relative to the shaft member 21 by a compression spring 23. The wheel 22 can slide toward the movable position, with its center 22c furthest from the motor axis J, against the biasing force of the compression spring 23. For example, when the engaging portion 24, described later, is pushed to the right by the driver projection 16, the wheel 22 supporting the engaging portion 24 moves radially from the initial position to the movable position along the guides of the sliding surface 22e and the support plane 21d.

[0033] As shown in Figures 3 and 4, multiple engagement parts 24 are mounted along the outer periphery of the wheel 22. In this embodiment, for example, 10 engagement parts 24 are provided. A cylindrical shaft member (pin) is used for each engagement part 24. The engagement parts 24 are provided at predetermined intervals in the circumferential direction of the wheel 22. A relief part 22d without engagement parts 24 is provided in a range of approximately 1 / 4 of the circumference between the first engagement part 24a and the last engagement part 24b. The left side region of the wheel 22 enters the driving passage 2a through a window part 25b provided in the mechanism case 25. The engagement parts 24 that have entered the driving passage 2a engage with the bottom of the driver projection 16 of the driver 30, which will be described later. With at least one of the engagement parts 24 engaged with the bottom of the driver projection 16, the wheel 22 is rotated counterclockwise in Figures 3 and 4. This causes the driver 30 and piston 14 to move upward.

[0034] As shown in Figure 5, the wheel 22 has a front flange portion 22a and a rear flange portion 22b that are parallel to each other and spaced at a constant distance from each other. The front flange portion 22a and the rear flange portion 22b are formed to have the same radial overhang shape. Each engaging portion 24 is held at a predetermined position in the circumferential direction of the wheel 22 by a through hole provided in the front flange portion 22a and a grooved hole provided in the rear flange portion 22b. Each engaging portion 24 is supported on the wheel 22 so as to be rotatable around its respective axis.

[0035] As shown in Figures 3, 6, and 7, the driver 30 has a vertically elongated driver body 15 and a plurality of rack-tooth shaped driver protrusions 16 that project to the right from the right side of the driver body 15. In this embodiment, 10 driver protrusions 16 are arranged in the longitudinal direction (vertical direction) of the driver body 15. Each driver protrusion 16 is provided in a shape that protrudes to the right and has its bottom facing downward. The driver protrusions 16 are approximately triangular when viewed from the front or back. Each driver protrusion 16 is provided at a predetermined interval in the vertical direction. Each driver protrusion 16 has approximately the same length of projection to the right. The bottom of each driver protrusion 16 engages with one of the engaging portions 24.

[0036] As shown in Figures 3, 6, and 7, the driver body 15 has a pair of first protrusions 15e that project forward from the driver body 15 and a single second protrusion 15g that projects forward from the driver body 15. The pair of first protrusions 15e are provided at the left and right ends of the driver body 15, respectively. The second protrusion 15g is provided midway between the pair of first protrusions 15e in the left-right direction. The first protrusions 15e and the second protrusion 15g extend long in the vertical direction and are parallel to each other. A recess 15f that extends long in the vertical direction is provided between the first protrusions 15e and the second protrusion 15g. The first protrusions 15e and the second protrusion 15g are each approximately rectangular in shape when viewed from the driving direction. The first protrusions 15e project forward to a height approximately the same as the thickness of the driver protrusion 16 in the front-rear direction. The second protrusion 15g has a lower forward projection height than the first protrusion 15e.

[0037] As shown in Figures 1 and 3, the lower end of the second protrusion 15g of the driver body 15 is provided with a planar tip surface 15a perpendicular to the vertical direction. The tip surface 15a strikes the head of the driving tool N. The left-right center of the tip surface 15a strikes the left-right striking center of the driving tool N. The second protrusion 15g protrudes forward at approximately the same height as the head of the driving tool N.

[0038] As shown in Figures 3, 6, and 7, the upper part of the driver body 15 is provided with a connecting portion 15b that connects to the connecting portion 14a of the piston 14. A circular through hole 15d is formed in the center of the connecting portion 15b, extending in the front-to-back direction. A cylindrical connecting pin 17 is press-fitted into the through hole 15d so as to protrude in both the front and back directions. The center of the through hole 15d (the axis center of the connecting pin 17) is the rotation center 15c of the driver body 15 relative to the piston 14. The rotation center 15c is located to the right of the left-to-right width centerline K of the driver body 15 and on the left-to-right width centerline L of the piston 14.

[0039] As shown in Figures 1 and 3, the lower part of the piston 14 is provided with a connecting portion 14a that can be connected to the connecting portion 15b of the driver body 15. The connecting portion 14a is provided with a driver insertion groove 14c into which the driver body 15 can be inserted through an opening at its lower end. The driver insertion groove 14c has an opening width in the front-to-back direction that is slightly larger than the thickness of the connecting portion 14a in the front-to-back direction. The opening at the lower end of the driver insertion groove 14c is provided with an opening width in the left-to-right direction that is larger than that of the connecting portion 15b so that the driver body 15 can rotate in the left-to-right direction with a predetermined range of motion.

[0040] As shown in Figures 1 and 3, the connecting portion 14a is provided with a circular through-hole 14b that penetrates in the front-rear direction. The through-hole 14b intersects with and communicates with the driver insertion groove 14c. The through-hole 14b is provided with a diameter that allows the connecting pin 17 to be inserted. The center of the through-hole 14b is located on the left-right width centerline L of the piston 14. The connecting pin 17 protrudes both forward and backward from the connecting portion 15b of the driver body 15. The front and rear protrusions of the connecting pin 17 are inserted into the through-hole 14b. As a result, the connecting pin 17 is supported by the connecting portion 14a so that it can rotate within the through-hole 14b. The connecting pin 17 rotates together with the driver body 15 around the rotation center 15c. At the bottom of the piston 14, a cushion receiving surface 14d is provided radially outward from the connecting portion 14a, which contacts the cushion 18 described later. The cushion receiving surface 14d is provided in a substantially planar shape that is substantially perpendicular to the vertical direction.

[0041] As shown in Figures 1-4, a cushion 18 is provided at the bottom of the cylinder 12 to absorb the impact at the lower moving end of the piston 14. The cushion 18 is made of an elastic material such as rubber or synthetic resin, for example, urethane rubber. The cushion 18 is provided in a substantially cylindrical shape. A through hole 18a is provided in the center of the cushion 18, penetrating the cushion 18 in the vertical direction. The inner circumferential surface of the through hole 18a is circular when viewed from the driving direction (vertical direction). A driver 30 is inserted through the through hole 18a. The diameter of the through hole 18a is provided such that the driver 30 does not come into contact with the cushion 18 regardless of its position from the upper moving end to the lower moving end. The cushion 18 is positioned such that the center of the through hole 18a in the left-right and front-back directions lies on the width centerline L of the piston 14. Also, the thickness of the cushion in the left-right and front-back directions is substantially the same. Therefore, the cushion 18 contacts the cushion receiving surface 14d of the piston 14 evenly in the left-right and front-back directions.

[0042] The left-right thickness of the cushion 18 is approximately the same in the area to the left of the driver 30 where the driver protrusion 16 does not protrude, and in the area to the right of the driver 30. To increase the volume of contact between the cushion 18 and the piston 14, a shape in which the left-right thickness of the cushion 18 is further increased in the area to the left of the driver 30 can be considered. However, in this shape, the left-right symmetry of the cushion 18 is reduced. Therefore, when the piston 14 collides with the cushion 18, the piston 14 may tilt in the left-right direction. Repeated driving operations may cause wear on the inner circumferential surfaces of the piston 14 and the cylinder 12 due to the tilt of the piston 14. The tilt of the piston 14 during collision can be similarly considered for the front-rear thickness of the cushion 18. Therefore, the cushion 18 is preferably structured with high symmetry in the left-right and front-rear directions, and is preferably cylindrical or a regular polygonal tube. More preferably cylindrical.

[0043] As shown in Figures 3 and 4, a guide member 19 is provided below the cushion 18 and to the left of the lift mechanism 20 to guide the driver 30 in the vertical direction. The guide member 19 extends long in the vertical direction. The left side wall of the driver body 15, which does not have the driver projection 16, is guided in the driving direction by the right side wall of the guide member 19. Moreover, the left and right side walls 2b of the driving passage 2a are arranged symmetrically with respect to the width centerline M of the driving nose portion 2. The left side wall of the downward-moving driver body 15 is guided in the driving direction by the side wall 2b. Thus, the driver body 15 is guided so that the width centerline K of the driver body 15 is coaxial with the width centerline M of the driving nose portion 2. The driving tool N is supplied to the driving passage 2a so that the striking center of its upper end is located on the width centerline M of the driving nose portion 2. Therefore, the striking center of the driving tool N is located coaxial with the width centerline K of the driver body 15.

[0044] As shown in Figures 3 and 4, the width centerline K of the driver body 15 is offset to the left, away from the lift mechanism 20, relative to the width centerline L of the piston 14. The width centerline K of the driver body 15 is parallel to the width centerline L of the piston 14 when the driver body 15 is not tilted in the left-right direction. The left-right distance between the width centerline K and the width centerline L is, for example, 40% or less, 30% or less, and 20% or less of the protruding length of the driver protrusion 16, and also, for example, 5% or more and 10% or more. The left-right distance between the width centerline K and the width centerline L is, for example, smaller than the left-right width of the second protrusion 15g.

[0045] Next, the sequence of operations for the driving tool 1 will be explained. Figure 3 shows the piston 14 and driver 30 in their initial waiting positions. The driver 30 and piston 14 are held in a stopped position slightly below the upper moving end. In this waiting state, the final engaging portion 24b immediately before the relief portion 22d engages with the bottom of the first (lowest) driver projection 16 counting from the driving direction side.

[0046] As shown in Figure 1, the contact arm 3 is pushed upward by the material to be driven W and the trigger 5 is pulled, which turns on the trigger switch 5a and starts the electric motor 26. When the electric motor 26 is started, the wheel 22 rotates counterclockwise in Figure 3. The final engaging part 24b moves the lowest driver projection 16 upward. This causes the piston 14 and driver 30 to move upward from their initial positions to the upper end. When the driver 30 moves to the upper end, the driving tool N is supplied from the magazine 9 onto the width centerline M in the driving passage 2a. When the driver reaches the state just before driving at the upper end, the final engaging part 24b disengages from the bottom of the driver projection 16. This causes the piston 14 and driver 30 to move downward due to the gas pressure in the pressure chamber 13. The driver body 15 moves downward with its width centerline K positioned on the width centerline M, and strikes one driving tool N with its tip surface 15a.

[0047] As the driver 30 moves downward, the relief portion 22d of the wheel 22 is located within the driving passage 2a. As a result, all the engaging portions 24 are retracted from within the driving passage 2a. This prevents interference between the engaging portions 24 and the driver projection 16, resulting in a smooth driving operation.

[0048] As shown in Figure 4, after the driving tool N strikes the wheel, the wheel 22 continues to rotate counterclockwise when the driver 30 reaches its lower moving end. The first engaging portion 24a immediately after the relief portion 22d engages with the bottom of the uppermost driver projection 16. This initiates a return movement that moves the piston 14 and the driver 30 upward in the opposite direction of driving. At the start of the return movement, the wheel 22 is biased by the compression spring 23 toward the driver 30 on the left, which is its initial position. Therefore, the center 22c of the wheel 22 is located on the motor axis J.

[0049] The wheel 22 continues to rotate from the state in which the driver 30 is at its lower moving end, as shown in Figure 4, to the state in which the driver 30 is at its initial position, as shown in Figure 3. Each engaging portion 24 sequentially engages with the bottom of the driver projection 16 located above. As a result, the driver 30 and piston 14 move upward against the gas pressure in the pressure accumulator chamber 13. At this time, the engaging portion 24 is pushed to the right by the driver projection 16, which may cause the wheel 22 to move radially to the right relative to the shaft member 21. When the final engaging portion 24b engages with the bottom of the lowest driver projection 16, the piston 14 and driver 30 reach their initial position. For example, by appropriately controlling the time from the start of the electric motor 26 (see Figure 1), the electric motor 26 is stopped when the driver 30 and piston 14 reach their initial position. This completes the series of driving operations. The initial position of the piston 14 and driver 30 is set below the upper moving end. In a single driving motion, the driver 30 is moved upward from its initial position to its upper end, and then downward by gas pressure to perform the driving motion.

[0050] As described above, the driving tool 1 has a cylinder 12 and a piston 14 that moves within the cylinder 12 by gas pressure, as shown in Figures 3 and 4. The driving tool 1 has a driver body 15 that moves together with the piston 14 to strike the driving tool N. The driving tool 1 has a plurality of driver protrusions 16 that protrude in the width direction from the driver body 15 along the side edge of the driver body 15. The driving tool 1 has a lift mechanism 20 that has a plurality of engaging parts 24 that engage with the plurality of driver protrusions 16 and rotates to return the driver body 15 to its initial position. The driving tool 1 has a through hole 18a through which the driver body 15 is inserted and a cylindrical cushion 18 that receives the impact of the piston 14. The driver body 15 is positioned such that the width centerline K of the driver body 15 is offset from the width centerline L of the piston 14 in the direction away from the lift mechanism 20 (to the left).

[0051] Therefore, the distance from the tip of the driver projection 16 to the width centerline L of the piston 14 can be shortened by the length of the offset between the width centerline K of the driver body 15 and the width centerline L of the piston 14. As a result, the opening area of ​​the through hole 18a of the cushion 18 through which the driver body 15 and the driver projection 16 are inserted can be reduced. As a result, the volume of the cushion 18 that contacts the cushion receiving surface 14d of the piston 14 can be increased. This improves the shock absorption of the cushion 18. In addition, the durability of the cushion 18 and the piston 14 that come into contact with each other can be improved.

[0052] As shown in Figures 3 and 4, the driver body 15 is rotatably connected to the piston 14 in the width direction. Therefore, the driver body 15 can rotate in the width direction within a predetermined angular range around the connection point with the piston 14. Thus, even if the driving nose portion 2 that guides the driver body 15 and the driver body 15 can slide against each other, the driver body 15 can rotate in the width direction to quickly avoid sliding with the driving nose portion 2. This prevents unintended force from being applied to the driver body 15 and reduces wear on the driver body 15.

[0053] As shown in Figures 3 and 4, the rotation center 15c of the driver body 15 relative to the piston 14 is located on the width centerline L of the piston 14. Therefore, the swing of the driver body 15 relative to the width centerline L of the piston 14 is substantially uniform in the width direction (left-right direction). The cushions 18 are arranged substantially uniformly around the width centerline L of the piston 14 in order to contact the cushion receiving surface 14d of the piston 14 evenly. Therefore, the driver body 15 can rotate substantially uniformly in the width direction with respect to the width center of the cushion 18. This prevents the driver body 15 or the driver projection 16 from unintentionally contacting the inner circumferential surface of the through hole 18a of the cushion 18 when the driver body 15 rotates in the width direction.

[0054] As shown in Figures 3 and 4, the driving tool 1 has a driving nose portion 2 that guides the driver body 15 at its end in the driving direction. The driving nose portion 2 is positioned such that its width centerline M is offset from the width centerline L of the piston 14 in a direction away from the lift mechanism 20. Therefore, the driver body 15 moves in the driving direction such that its width centerline K is located on the width centerline M of the driving nose portion 2. The driving tool N is supplied on the width centerline M of the driving nose portion 2. As a result, the driver body 15 can strike approximately the center of the driving tool N in the width direction. This allows the driving tool N to be ejected straight in the driving direction.

[0055] As shown in Figures 1-4, the inner circumferential surface of the through hole 18a in the cushion 18 is circular when viewed from the direction of movement of the driver body 15. Therefore, the piston 14 and the cushion 18 come into contact almost uniformly in the circumferential direction. As a result, the cushion 18 deforms almost uniformly in the circumferential direction when it receives an impact from the piston 14. This suppresses wear on specific parts of the cushion 18 and improves the durability of the cushion 18. It also suppresses unintentional tilting of the piston 14 when it comes into contact with the cushion 18. This suppresses wear on the piston 14 and the cylinder 12.

[0056] As shown in Figures 3 and 4, the lift mechanism 20 has a wheel 22 rotatably supported on the tool body 10 and a plurality of engaging parts 24 arranged along the circumferential direction of the wheel 22. At least one of the plurality of engaging parts 24 is movable relative to the wheel 22 in the radial direction of the wheel 22.

[0057] Therefore, the widthwise protrusion length of the driver projection 16 needs to be made longer by the amount of movement of the engaging portion 24, which is movable in the radial direction of the wheel 22. By positioning the width centerline K of the driver body 15 to the left, away from the lift mechanism 20, relative to the width centerline L of the piston 14, the reduction in the volume of the cushion 18 can be suppressed even when the protrusion length of the driver projection 16 is made longer. In addition, the engaging portion 24 can be brought closer to the width centerline L of the piston 14 by the amount of the offset between the width centerline K of the driver body 15 and the width centerline L of the piston 14. As a result, the force with which the engaging portion 24 pushes the bottom of the driver projection 16 upward acts near the width centerline L of the piston 14. This allows the driver 30 and the piston 14 to move straight upward.

[0058] As shown in Figures 6-8, the driver body 15 has first protrusions 15e on both sides in the width direction that project in the direction of movement of the driver body 15 and in the height direction intersecting the width direction. Therefore, the driver body 15 is guided by the first protrusions 15e provided on both sides in the width direction and moves straight in the driving direction. This increases the stability with which the driver body 15 strikes the driving tool N (see Figures 3 and 4) in the driving direction.

[0059] As shown in Figures 6-8, the driver body 15 has a second protrusion 15g that protrudes in the height direction at the center in the width direction, and the protrusion height of the second protrusion 15g is lower than that of the first protrusion 15e. Therefore, by reducing the protrusion height of the second protrusion 15g, the driver body 15 can be made lightweight. In addition, the driver body 15 strikes the driving tool N (see Figures 3 and 4) with the tip surface 15a of the lower end of the second protrusion 15g. Therefore, by providing the second protrusion 15g with a predetermined protrusion height, the driving tool N struck by the driver body 15 can be ejected with good stability.

[0060] Various modifications can be made to the embodiments described above. For example, a configuration in which the lift mechanism 20 is positioned to the right of the driver 30 has been illustrated. Alternatively, the lift mechanism 20 may be positioned to the left of the driver 30. In this case, the width centerline K of the driver body 15 is offset to the right with respect to the width centerline L of the piston 14.

[0061] Although an example is shown of a wheel 22 having 10 engaging parts 24 and a driver 30 having 10 driver protrusions 16, the number of engaging parts 24 and driver protrusions 16 is not limited to 10. The number of engaging parts 24 and driver protrusions 16 is appropriately set depending on factors such as the stroke of the driver 30 and the size of the tool body 10. The spacing of each engaging part 24 in the circumferential direction of the wheel 22 and the vertical spacing of each driver protrusion 16 are not limited to those exemplified and may be changed as appropriate.

[0062] An example of a pin-shaped engaging portion 24 is shown. Alternatively, for example, the engaging portion 24 may be a pinion tooth formed along the outer edge of the wheel 22. An example of a lift mechanism 20 in which the wheel 22 moves radially relative to the shaft member 21 is shown. Alternatively, the driver 30 and piston 14 of this disclosure may be applied to a driving tool 1 equipped with a lift mechanism 20 in which the wheel 22 does not move radially relative to the shaft member 21. Multiple driver protrusions 16 that are approximately triangular when viewed from the front and rear directions and have approximately the same protruding length are shown. The shape and protruding length of the driver protrusions 16 are not limited to those shown and may be changed as appropriate. In addition, the shape or protruding length may be changed for each driver protrusion 16.

[0063] An example of a cushion 18 is shown that is roughly cylindrical, with the inner circumferential surface of the through-hole 18a being circular when viewed from above. Alternatively, for example, the cushion 18 may be provided in the shape of a regular polygonal cylinder, and the inner circumferential surface of the through-hole 18a may also be formed in the shape of a regular polygon following the outer circumferential surface. Alternatively, only the outer circumferential surface may be provided in the shape of a regular polygon, and the inner circumferential surface of the through-hole 18a may be provided in the circular shape. Furthermore, a relief portion may be provided on the inner circumferential surface of the through-hole 18a of the cushion 18 only in the area through which the driver projection 16 passes to avoid interference with the driver projection 16. The shape of the inner circumferential surface of the through-hole 18a is generally circular when viewed from above, but the relief portion is cut out (extended) radially outward from the circular portion. The relief portion is provided with a width slightly larger than the thickness of the driver projection 16 in the circumferential direction of the inner circumferential surface of the through-hole 18a. Even when a relief portion is provided in the cushion 18 in this way, the length of the relief portion in the radial direction of the cushion 18 can be shortened by offsetting the width centerline K of the driver body 15 in the opposite direction to the protruding direction of the driver protrusion 16 relative to the width centerline L of the piston 14. [Explanation of symbols]

[0064] 1… Driving tool 2...Driver nose section (driver guide), 2a...Driver passage, 2b...Side wall 2c…Ejection port 3… Contact Arm 4…Grip 5...Trigger, 5a...Trigger switch 6…Battery mounting section 7…Battery pack 8…Controller 9... Magazine 10...Tool body 11...Main housing, 11a...Drive unit case 12... Cylinder 13...Accumulation chamber 14...Piston, 14a...Connecting part, 14b...Through hole, 14c...Driver insertion groove 14d...Cushion receiving surface 15...Driver body, 15a...Tip surface, 15b...Connecting part, 15c...Center of rotation 15d…Through hole, 15e…First protrusion, 15f…Concave, 15g…Second protrusion 16... Driver protrusion 17…Connecting pin 18...Cushion, 18a...Through hole 19… Guide member 20…Lift mechanism 21...Shaft member, 21a...Bearing, 21b...Connecting part, 21c...Support part, 21d...Support plane 21e... Spring housing section, 22...Wheel, 22a...Front flange, 22b...Rear flange, 22c...Center 22d...Relief section, 22e...Sliding surface 23... Compression spring 24...Engaging part, 24a...First engaging part, 24b...Final engaging part 25... Mechanism case, 25a... Lid member, 25b... Window section 26...Electric motor, 26a...Output shaft, 26b...Stator, 26c...Rotor 26d, 26e… bearings 27...Reduction gear train, 27a...(final stage) carrier, 27b...Bearing 28...Gear train case 30... Driver N... driving tool W... material to be driven in J...Motor axis K... (The width center line of the driver unit) L... (Piston) width centerline M... (Driver guide) width center line

Claims

1. It is a driving tool, Cylinder and A piston that moves within the cylinder by gas pressure, A driver body that moves together with the piston to strike the driving tool, Multiple driver protrusions project in the width direction from the driver body along the side edge of the driver body, A lift mechanism comprising multiple engaging parts that engage with the multiple driver protrusions and which rotates to return the driver body to its initial position, The driver body has a through hole through which it is inserted and has a cylindrical cushion that receives the impact of the piston, The driver body is positioned such that the width centerline of the driver body is offset from the width centerline of the piston in a direction away from the lift mechanism. The driver body is rotatably connected to the piston in the width direction, A driving tool in which the rotational center of the driver body relative to the piston is located on the width center line of the piston.

2. The driving tool according to claim 1, The end in the driving direction has a driver guide that guides the driver body, A driving tool in which the driver guide is positioned such that the width center line of the driver guide is offset from the width center line of the piston in a direction away from the lift mechanism.

3. A driving tool according to claim 1 or 2, The inner circumferential surface of the through hole in the cushion is circular when viewed from the direction of movement of the driver body, in the driving tool.

4. A driving tool according to claim 1 or 2, The lift mechanism has a wheel rotatably supported on the tool body and a plurality of engaging parts arranged along the circumferential direction of the wheel. At least one of the plurality of engaging portions is a driving tool that is movable relative to the wheel in the radial direction of the wheel.

5. A driving tool according to claim 1 or 2, The driver body is a driving tool having first protrusions on both sides in the width direction that protrude in the direction of movement of the driver body and in the height direction intersecting the width direction.

6. The driving tool according to claim 5, The driver body has a second protrusion that protrudes in the height direction at the center in the width direction, and the second protrusion has a lower protrusion height than the first protrusion.

Images