Work equipment

Abstract

Provided is a work machine having improved durability. This nailing machine (work machine) comprises a striking part 13 that is formed in a rod shape extending so as to be centered on an axis 34d, an ejection part that contacts the outer peripheral surface of the striking part 13 to thereby guide movement of the striking part 13 toward one side in an axial direction 34e, and a supply part that biases a latch toward one side in a direction intersecting the axial direction 34e to thereby supply the latch to the ejection part. The striking part 13 has a distal-end section 34a, and a central section 34b provided at a different position than the distal-end section 34a in the axial direction 34e. At least part of an outer peripheral surface 34f of the distal-end section 34a (distal-end-section outer peripheral surface 34h) that is located on the side opposite from the supply part relative to the axis 34d protrudes to a greater extent than an outer peripheral surface 34f of the central section 34b (central-section outer peripheral surface 34j) that is located on the side opposite from the supply part relative to the axis 34d.

Description

[Technical field]

[0001] The present invention relates to a work machine such as a nail driver. [Background technology]

[0002] As an example of a working machine, a nail driver that drives a piston with compressed air to strike a fastener is known. As an example of such a nail driver, a nail driver in which a driver blade attached to the piston moves downward while being guided by a nose to strike a fastener is described in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-196067 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the nail driver described in the above Patent Document 1, the driver blade and the nose slide at high speed, generating heat and forming an altered layer on the surface of the driver blade. This altered layer is hard and brittle, so it is prone to microcracks due to impacts during driving. As a result, the driver blade may break from the microcracks, and there has been a demand for improving the durability of the driver blade.

[0005] On the other hand, it is possible to change the shape of the driver blade to suppress the formation of the altered layer, but in this case, it is necessary to consider the relationship between the driver blade and sliding parts other than the nose, such as the nail, and the structure of the driver blade so that it is less likely to break even if it is subjected to impact when driving in.

[0006] An object of the present invention is to provide a work machine having improved durability. [Means for solving the problem]

[0007] The working machine according to one embodiment includes a striking section formed in a rod shape extending about an axis and moving to one side in the axial direction to strike a fastener, an ejection section that contacts an outer peripheral surface of the striking section to guide the movement of the striking section to the one side in the axial direction, and a supply section that supplies the fastener to the ejection section by biasing the fastener to one side in a direction intersecting the axial direction, and the striking section is a supply part side outer circumferential surface forming a straight portion of a cross section in a direction perpendicular to the axial direction; and a counter supply part side outer circumferential surface not included in the supply part side outer circumferential surface; The rotor includes a first portion, a second portion, and a third portion that are provided at different positions in the axial direction, and the first portion and the third portion The supply portion side outer circumferential surface is the second part The supply portion side outer circumferential surface The first portion and the third portion do not protrude further. The outer peripheral surface on the opposite side to the supply portion At least a portion of the second portion The outer peripheral surface on the opposite side to the supply portion The second portion is located between the first portion and the third portion, and the first portion is located at the top dead center position of the striking portion. Minutes The first portion or the third portion abuts against the ejection portion when the striking portion is at the bottom dead center. Effect of the Invention

[0008] According to the present invention, the durability of the work machine can be improved. [Brief description of the drawings]

[0009] [Figure 1] 1 is an external view showing a nail driver as an example of a working machine according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a cross-sectional view of the nail driver shown in FIG. 1 at a top dead center position. [Diagram 3] 2 is an external view of a driver blade provided in the nail driver shown in FIG. 1. [Figure 4] 4A and 4B are diagrams showing the structure of the driver blade shown in FIG. 3, in which (a) is a partially enlarged view of the tip portion, (b) is a cross-sectional view taken along line BB in (a), and (c) is a view taken along line C in (a). [Diagram 5] 4 is an external view of the driver blade shown in FIG. 3 as viewed from the feeder side. [Figure 6] 2 is a cross-sectional view of the nail driver shown in FIG. 1 at a position between the top dead center and the bottom dead center. [Figure 7] FIG. 2 is a cross-sectional view of the nail driver shown in FIG. 1 at a bottom dead center position. [Figure 8] 2 is an enlarged partial cross-sectional view showing the structure of the nail driver shown in FIG. 1 taken along line AA. [Figure 9] 1A and 1B are diagrams showing a driver blade of a first modified example of the nail driver of the present invention, in which (a) is an external view and (b) is an enlarged view of the tip of (a). [Figure 10] 5A and 5B are diagrams showing a driver blade of a second modified example of the nail driver of the present invention, in which (a) is an external view and (b) is an enlarged view of the tip of (a). [Figure 11] 11A and 11B are diagrams showing the driver blade shown in FIG. 10, in which (a) is a cross-sectional view taken along line DD in FIG. 10A, and (b) is a cross-sectional view showing the relationship between the ejection portion and the rail portion. [Figure 12] 10A and 10B are diagrams showing a driver blade of a third modified example of the nail driver of the present invention, in which (a) is an external view and (b) is an E-E sectional view of (a). [Figure 13] 13A and 13B are views showing the driver blade shown in FIG. 12, in which (a) is an enlarged view of the tip portion of FIG. 12A, and (b) is a view seen in the direction of arrow F in FIG. 12A. [Figure 14] 10A and 10B are diagrams showing a driver blade of a fourth modified example of the nail driver of the present invention, in which (a) is an external view and (b) is a GG cross-sectional view of (a). [Figure 15] 15A and 15B are views showing the driver blade shown in FIG. 14, in which (a) is an enlarged view of the tip portion of FIG. 14A, and (b) is a view seen in the direction of arrow H in FIG. 14A. [Figure 16] 10A and 10B are diagrams showing a driver blade of a fifth modified example of the nail driver of the present invention, in which (a) is an external view and (b) is a cross-sectional view taken along line II in (a). [Figure 17] 17A and 17B are views showing the driver blade shown in FIG. 16, in which (a) is an enlarged view of the tip portion of FIG. 16A, and (b) is a view seen in the direction of arrow J in FIG. 16A. [Figure 18]13A and 13B are diagrams showing a driver blade of a sixth modified example of the nail driver of the present invention, in which (a) is an external view and (b) is a KK cross-sectional view of (a). [Figure 19] 19A and 19B are views showing the driver blade shown in FIG. 18, in which (a) is an enlarged view of the tip portion of FIG. 18A, and (b) is a view seen in the direction of arrow M in FIG. 18A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A working machine according to the present embodiment will be described with reference to the drawings. In this embodiment, a nail driver will be described as an example of a working machine. Note that the same or equivalent elements shown in each drawing are given the same reference numerals.

[0011] The nail driver 10 of the present embodiment 1 shown in Figs. 1 and 2 has a housing 11, an ejection unit 12, a striking unit 13, a trigger 14, and a push lever 15. The housing 11 has a body 18, a handle 19, and a head cover 20. The body 18 is cylindrical, and the handle 19 is connected to the body 18. The head cover 20 is fixed to one end of the body 18 in the longitudinal direction, and closes an opening of the body 18. The ejection unit 12, also called a nose, is fixed to the other end of the body 18 in the longitudinal direction. A plug 21 is provided on the handle 19, and an air hose is connected to the plug 21.

[0012] A cylinder 22 is provided within the body 18. The cylinder 22 is movable relative to the housing 11 in a direction along a center line A1. The center line A1 is the center line of the cylinder 22. The striking section 13 is disposed throughout the inside and outside of the cylinder 22. The striking section 13 is operable relative to the cylinder 22 in a direction along the center line A1. A pressure accumulator chamber 23 is provided throughout the handle 19, body 18 and head cover 20. Compressed air supplied from an air hose is accumulated in the pressure accumulator chamber 23.

[0013] Furthermore, the head cover 20 has a passage 24 and an exhaust valve chamber 26. The passage 24 is connected to the outside of the housing 11. Furthermore, a mount portion 27 is attached to the head cover 20. The mount portion 27 has a passage 28 and a passage 29. The passage 29 is connected to the passage 24 via the passage 28. The mount portion 27 supports an exhaust valve 30. The exhaust valve 30 is movable in a direction along a center line A1 relative to the mount portion 27. When the exhaust valve 30 is actuated, the passage 29 is opened and closed.

[0014] In addition, a valve seat 31 is attached to the mount portion 27. The valve seat 31 is made of synthetic rubber, and has an upper-piston chamber 32. The upper-piston chamber 32 is connected to the passage 29.

[0015] The striking section 13 has a piston 33 and a driver blade 34. The piston 33 is provided in the cylinder 22 and can operate in a direction along the center line A1 relative to the cylinder 22. The piston 33 is urged by the pressure in the piston upper chamber 32 in a direction along the center line A1 away from the valve seat 31. A seal member 25 is attached to the outer circumferential surface of the piston 33. The seal member 25 contacts the inner circumferential surface of the cylinder 22. The driver blade 34 attached to the piston 33 is a member that strikes the nail (fastener) 16 by moving to one side (fastener protruding side) in the axial direction 34e of FIG. 1, which is a direction along the axis 34d of the driver blade 34 shown in FIG. 3.

[0016] As shown in FIG. 1, a piston lower chamber 35 is provided between the piston 33 and the injection part 12 in the direction along the center line A1 in the cylinder 22. The seal member 25 seals the piston lower chamber 35. A return air chamber 36 is provided between the body 18 and the cylinder 22. Passages 37 and 38 are provided to penetrate the cylinder 22 in the radial direction. A check valve 41 is provided on the outer circumferential surface of the cylinder 22. The check valve 41 is operated by the pressure in the cylinder 22 and opens and closes the passage 37. The passage 38 constantly connects the piston lower chamber 35 and the return air chamber 36. The passage 38 is disposed between the passage 37 and the injection part 12 in the direction along the center line A1.

[0017] A bumper 39 is provided inside the cylinder 22. The bumper 39 is disposed in the cylinder 22 at a position closest to the injection part 12 in the direction of the center line A1. The bumper 39 is made of synthetic rubber or silicone rubber. The bumper 39 has an axial hole 40, and the driver blade 34 is movable in the axial hole 40 in the direction of the center line A1. A piston lower chamber 35 is formed between the piston 33 and the bumper 39 in the cylinder 22.

[0018] Furthermore, ejection unit 12 is fixed to body 18, and has ejection path 43. Ejection path 43 is connected to axial hole 40. Driver blade 34 is movable in a direction along center line A1 within axial hole 40 and ejection path 43. Ejection unit 12 contacts outer peripheral surface 34f of driver blade 34 shown in FIG. 3, thereby guiding movement of driver blade 34 to one side (stopper protruding side) in axial direction 34e.

[0019] In addition, a push lever 15 is attached to the ejection unit 12. The push lever 15 is operable in a direction along the center line A1 relative to the housing 11 and the ejection unit 12. The push lever 15 is urged in a direction away from the housing 11 by a spring 42, which is an urging member. The push lever 15, urged by the spring 42, comes into contact with a stopper 44 and stops at the initial position. When the tip of the push lever 15 is pressed against the target material 17, the push lever 15 is operable in a direction approaching the housing 11 against the urging force of the spring 42.

[0020] Also, a magazine 45 is attached to the nail driver 10. The magazine 45 can store a plurality of nails 16, which are fasteners. The magazine 45 is supported by the ejection unit 12 and the handle 19. The magazine 45 is provided with a feeder 46, which is a supply unit for the nails 16, and a spring 47, and the spring 47 biases the nails 16 via the feeder 46 toward one side (the ejection unit side) in a direction intersecting the axial direction 34e of the driver blade 34 (hereinafter, this direction is also referred to as a biasing direction B1). That is, the feeder 46 sends the nails 16 to the ejection path 43 by the biasing force of the spring 47.

[0021] Next, an example of the operation of the nail driver 10 when the nail driver 10 is used to drive a nail 16 into a target material 17 will be described. As shown in FIG. 1, when a user applies an operating force to the trigger 14 and the push lever 15 is pressed against the target material 17, the pressure in the pressure accumulator chamber 23 shown in FIG. 2 is transmitted to the piston upper chamber 32, and the piston 33 and the driver blade 34 move down. Then, the driver blade 34 strikes the nail 16. The struck nail 163 is driven into the target material 17.

[0022] As shown in Fig. 6, when the sealing member 25 moves between the passage 37 and the bumper 39 while the striking part 13 is descending, the check valve 41 is actuated by the pressure of the compressed air flowing into the cylinder 22 to open the passage 37. As a result, part of the compressed air in the cylinder 22 flows through the passage 37 into the return air chamber 36. As a result, as shown in Fig. 7, when the striking part 13 descends and the piston 33 collides with the bumper 39, the bumper 39 absorbs part of the kinetic energy of the striking part 13. Also, the striking part 13 stops at the bottom dead center. When the striking part 13 stops at the bottom dead center, the piston 33 is pressed against the bumper 39, and the piston 33 blocks the inside of the cylinder 22 from the shaft hole 40.

[0023] When the push lever 15 moves away from the target material 17 due to the reaction of the striking part 13 driving the nail 16 into the target material 17, the push lever 15 is actuated by the urging force of the spring 42 and stops at the initial position. Then, the compressed air in the exhaust valve chamber 26 is discharged to the outside. Furthermore, the exhaust valve 30 is actuated to connect the passage 29 and the passage 28, and the compressed air in the piston upper chamber 32 is discharged to the outside. When the pressure in the piston upper chamber 32 decreases, the piston 33 is raised by the pressure of the compressed air supplied from the return air chamber 36 to the piston lower chamber 35. Then, the piston 33 comes into contact with the valve seat 31, and the striking part 13 stops at the top dead center.

[0024] Next, the driver blade 34 provided in the nail driver 10 of this embodiment will be described. As shown in FIG. 3, the driver blade 34 is a member that constitutes the striking portion 13 together with the piston 33, and is formed in a rod shape extending around the axis 34d. The driver blade 34 has a first portion and a second portion provided at a position different from the first portion in the axial direction 34e. Furthermore, the driver blade 34 has a third portion provided at a position different from the first portion and the second portion in the axial direction 34e. That is, the driver blade 34 has a first portion, a second portion, and a third portion provided at different positions in the axial direction 34e.

[0025] In this embodiment, the first and second parts are provided on one side (the stopper protruding side) of the third part in the axial direction 34e, and the first part is provided on one side (the stopper protruding side) of the second part in the axial direction 34e. Specifically, the first part is the tip part 34a of the driver blade 34, the second part is the center part 34b, and the third part is the base part 34c. Therefore, the center part 34b, which is the second part, is located between the tip part 34a, which is the first part, and the base part 34c, which is the third part.

[0026] In the driver blade 34, the tip outer peripheral surface 34g, which is the outer peripheral surface 34f located on the feeder 46 side with respect to the axis 34d of the tip 34a (see FIG. 2), does not protrude from the center outer peripheral surface 34i, which is the outer peripheral surface 34f of the center 34b on the feeder 46 side with respect to the axis 34d. In the driver blade 34 shown in FIG. 3, the tip outer peripheral surface 34g and the center outer peripheral surface 34i are flat surfaces of the same height as shown in FIGS. 4(a) and (b). In addition, the tip outer peripheral surface 34h, which is the outer peripheral surface 34f located on the opposite side of the feeder 46 with respect to the axis 34d of the tip 34a (hereinafter also referred to as the anti-feeder side), protrudes from the center outer peripheral surface 34j, which is the outer peripheral surface 34f of the center 34b on the anti-feeder side with respect to the axis 34d, as shown in FIGS. 4(a) and (b). In the driver blade 34, at least a part of the tip outer peripheral surface 34h may protrude from the central outer peripheral surface 34j with respect to the axis 34d. In the driver blade 34 of this embodiment, the cross-sectional shape of the tip 34a in the direction perpendicular to the axial direction 34e is composed of an arc shape and a straight line, as shown in FIG. 4(b). That is, the tip outer peripheral surface 34h on the opposite side to the feeder in the tip 34a is an arc-shaped surface, while the tip outer peripheral surface 34g on the feeder 46 side in the tip 34a is a flat surface. Similarly, the central outer peripheral surface 34j on the opposite side to the feeder in the central portion 34b is an arc-shaped surface, while the central outer peripheral surface 34i on the feeder 46 side in the central portion 34b is a flat surface. Therefore, in the driver blade 34, the tip outer peripheral surface 34h, which is an arc-shaped surface on the opposite side to the feeder, protrudes with respect to the axis 34d from the central outer peripheral surface 34j, which is also an arc-shaped surface. The shapes of the cut surfaces of the tip portion 34a and the central portion 34b in the direction perpendicular to the axial direction 34e are similar to each other. In detail, the circle forming the arc-shaped tip outer peripheral surface 34h on the opposite side to the feeder in the tip portion 34a and the circle forming the arc-shaped central outer peripheral surface 34j on the opposite side to the feeder in the central portion 34b are circles having the same center C1 as shown in Fig. 4(c). Furthermore, the tip outer peripheral surface 34g on the feeder 46 side in the tip portion 34a and the central outer peripheral surface 34i on the feeder 46 side in the central portion 34b are flat surfaces of the same height.Therefore, the shapes of the cut surfaces of the tip portion 34a and the central portion 34b in a direction perpendicular to the axial direction 34e are similar to each other.

[0027] Here, the amount of protrusion of the tip outer peripheral surface 34h from the central outer peripheral surface 34j is preferably 0.05% or more and less than 0.5% of the length L2 in the axial direction 34e of the central portion 34b shown in Fig. 4(a). As an example, when the length L2 in the axial direction 34e of the central portion 34b of the driver blade 34 is 105 mm, the amount of protrusion of the tip outer peripheral surface 34h from the central outer peripheral surface 34j is about 0.05 mm to about 0.5 mm. As an example, as shown in Fig. 4(c), the diameter D1 of the circle of the center C1 forming the tip outer peripheral surface 34h, which is an arc-shaped surface, is 7.0 mm, and the diameter D2 of the circle of the center C1 forming the central outer peripheral surface 34j, which is an arc-shaped surface, is 6.6 mm to 6.8 mm. In this case, the amount of protrusion of the tip outer peripheral surface 34h relative to the central outer peripheral surface 34j is 0.1 mm to 0.2 mm, which falls within the above-mentioned range of about 0.05 mm to less than about 0.5 mm.

[0028] In addition, in the driver blade 34, the root outer peripheral surface 34k, which is the outer peripheral surface 34f located on the feeder 46 side with respect to the axis 34d of the root portion 34c, does not protrude from the center outer peripheral surface 34i, which is the outer peripheral surface 34f of the center portion 34b on the feeder 46 side with respect to the axis 34d. As with the relationship between the tip portion 34a and the center portion 34b, in the driver blade 34 shown in FIG. 3, the root outer peripheral surface 34k and the center outer peripheral surface 34i are flat surfaces of the same height. Furthermore, the root outer peripheral surface 34m, which is the outer peripheral surface 34f located on the opposite side of the feeder with respect to the axis 34d of the root portion 34c, protrudes from the center outer peripheral surface 34j, which is the outer peripheral surface 34f of the center portion 34b on the opposite side of the feeder with respect to the axis 34d, as with the relationship between the tip portion 34a and the center portion 34b.

[0029] As with the tip 34a, at least a part of the root outer peripheral surface 34m may protrude from the central outer peripheral surface 34j with respect to the axis 34d. In the driver blade 34 of this embodiment, the cross-sectional shape of the root 34c in the direction perpendicular to the axial direction 34e is also composed of an arc and a straight line, and is the same as the cross-sectional shape of the tip 34a. That is, the root outer peripheral surface 34m, which is the outer peripheral surface 34f of the root 34c, is an arc-shaped surface. Therefore, in the relationship between the root 34c and the central portion 34b, the root outer peripheral surface 34m, which is the arc-shaped surface on the opposite side to the feeder, protrudes from the central outer peripheral surface 34j, which is also an arc-shaped surface, with respect to the axis 34d.

[0030] As an example, the amount of protrusion of the base outer peripheral surface 34m relative to the central outer peripheral surface 34j is also 0.1 mm to 0.2 mm.

[0031] As a result, in the driver blade 34 of this embodiment, the outer peripheral surface 34f on the opposite side to the feeder of the central portion 34b is recessed from the outer peripheral surfaces 34f on the opposite side to the feeder of the tip portion 34a and the base portion 34c. In other words, the outer peripheral surface 34f on the opposite side to the feeder of the driver blade 34 is shaped with a step, and the central portion 34b is narrower than the tip portion 34a and the base portion 34c. However, on the feeder 46 side of the driver blade 34, there is no step from the base portion 34c to the central portion 34b and the tip portion 34a, and the surface is flat and of the same height.

[0032] Here, we will explain why there is a step on the outer peripheral surface 34f on the anti-feeder side of the driver blade 34 in this embodiment, i.e., why the outer peripheral surface 34f on the anti-feeder side of the central portion 34b is recessed further than the outer peripheral surface 34f on the anti-feeder side of the tip portion 34a and the root portion 34c.

[0033] In the nail driver 10 of this embodiment, as shown in FIG. 2, the feeder 46 always presses the nails 16 stored in the magazine 45 against the striking section 13 along the biasing direction B1 intersecting with the axial direction 34e. Specifically, while the striking section 13 is striking a nail 16, the feeder 46 presses other nails 16 against the striking section 13 along the biasing direction B1 intersecting with the axial direction 34e. As a result, even while the striking section 13 is moving to strike the nail 16, the nail 16 to be struck next is pressed against the driver blade 34 by the feeder 46. In addition, the driver blade 34 is provided with a tapered portion 34p tapered toward the tip as shown in FIG. 4(c) and FIG. 5 so as not to strike the nail 16 waiting to be struck next at the same time. However, since the waiting nails 16 are also pressed against the driver blade 34 by the feeder 46, the driver blade 34 is pressed toward the opposite side by the pressing force of the waiting nails 16 and moves toward the protruding side while abutting against the inner wall 12a of the ejection section 12. At this time, since the outer peripheral surface 34f on the opposite side of the tip portion 34a and the base portion 34c of the driver blade 34 protrudes from the outer peripheral surface 34f on the opposite side of the center portion 34b, the outer peripheral surface 34f on the opposite side of the center portion 34b can be prevented from abutting against the inner wall 12a of the ejection section 12. In other words, since the outer peripheral surface 34f on the opposite side of the center portion 34b is recessed from the outer peripheral surface 34f on the opposite side of the tip portion 34a and the base portion 34c, the outer peripheral surface 34f on the opposite side of the center portion 34b can be prevented from abutting against the inner wall 12a of the ejection section 12.

[0034] Therefore, it is possible to prevent the center portion 34b of the driver blade 34 from sliding against the inner wall 12a of the ejection section 12 at high speed, generating heat and creating a deteriorated layer on the surface of the center portion 34b of the driver blade 34. This makes it possible to prevent breakage at the center portion 34b of the driver blade 34, to which a relatively large stress is applied. As a result, it is possible to improve the durability of the driver blade 34.

[0035] Furthermore, since the amount of protrusion of the tip outer peripheral surface 34h relative to the central outer peripheral surface 34j is 0.05% or more and less than 0.5% of the length L2 of the central portion 34b of the driver blade 34, it is possible to prevent the central outer peripheral surface 34j from contacting the inner wall 12a of the injection section 12, while suppressing a decrease in the durability of the driver blade 34 due to a decrease in the diameter D2 of the central outer peripheral surface 34j.

[0036] In addition, the driver blade 34 has a flat surface at the same height on the feeder 46 side from the base 34c to the center 34b and the tip 34a without any step, in other words, the tip outer peripheral surface 34k on the feeder 46 side of the base 34c and the tip outer peripheral surface 34g on the feeder 46 side of the tip 34a do not protrude from the central outer peripheral surface 34i on the feeder 46 side of the center 34b. The nails 16 are supplied from the magazine side. Therefore, since the feeder 46 side of the driver blade 34 is flat, it is possible to prevent the head of the nail 16 from getting caught on the step of the driver blade 34, causing vibration and adversely affecting the driving operation of the driver blade 34. In order to make the driver blade 34 compatible with the existing nails 16, the shape of the tip 34a needs to be common to existing nail drivers to some extent, so if a step is to be provided between the outer peripheral surface 34f of the tip 34a and the outer peripheral surface 34f of the central portion 34b, the diameter of the central portion 34b needs to be reduced. If the tip outer peripheral surface 34h on the opposite side to the feeder 46 protrudes from the central outer peripheral surface 34j on the opposite side to the feeder 46 of the central portion 34b, and the tip outer peripheral surface 34g on the feeder 46 side protrudes from the central outer peripheral surface 34i on the feeder 46 side of the central portion 34b, the diameter of the central portion 34b becomes excessively small, so that the driver blade 34 may be easily damaged from the central portion 34b regardless of the presence or absence of deterioration in the central portion 34b. However, according to the driver blade 34 of this embodiment, the tip outer surface 34g on the feeder 46 side does not protrude beyond the central outer surface 34i on the feeder 46 side of the central portion 34b, and the diameter of the central portion 34b does not become excessively small, thereby suppressing damage to the central portion 34b.

[0037] As shown in FIG. 4(a), the lower end surface 34n of the driver blade 34 includes a striking surface 34q that strikes the nail 16. The striking surface 34q is formed at an incline with respect to the axis 34d shown in FIG. 3 so that the lower end on the feeder 46 side protrudes toward one side (the fastener protruding side) of the axial direction 34e from the lower end on the opposite side to the feeder. The inclination angle θ of the striking surface 34q with respect to the direction perpendicular to the axial direction 34e is, for example, θ=5°. The inclination angle 5° of the striking surface 34q is for moving the tip of the nail 16 in contact with the inner wall 12a of the ejection section 12 while inclining the tip of the nail 16 by 5° with respect to the axis 34d shown in FIG. 3 so that the tip of the nail 16 does not move sideways when striking the nail 16. Specifically, as shown in FIG. 8, an inner wall 12a of the ejection section 12 is provided with a U-shaped groove 12b recessed toward the opposite side to the feeder, and while the nail 16 moves within the ejection section 12, the tip of the nail 16 moves while abutting against the U-shaped groove 12b. This allows the nail 16 to be driven into the desired position of the mating material 17 shown in FIG. 1 without the tip of the nail 16 being displaced sideways.

[0038] In addition, since the lower end of the striking surface 34q at the lower end of the driver blade 34 on the feeder 46 side protrudes from the lower end on the opposite side, a reaction force from the nail 16 acts on the feeder 46 side of the center portion 34b of the driver blade 34 at the time of striking, and a stress is applied to the opposite side of the center portion 34b of the driver blade 34 such that the opposite side stretches. Due to the influence of this stress, the opposite side of the center portion 34b of the driver blade 34 is easily damaged. In addition, as described above, the feeder 46 presses the nail 16 against the driver blade 34, and the center portion 34b of the driver blade 34 is easily brought into contact with the inner wall 12a of the ejection section 12.

[0039] However, in the driver blade 34 of this embodiment, even when the above-mentioned stress is applied so that the anti-feeder side of the central portion 34b is stretched, the outer peripheral surface 34f on the anti-feeder side of the central portion 34b is recessed from the outer peripheral surfaces 34f on the anti-feeder side of the tip portion 34a and the base portion 34c, so that the outer peripheral surface 34f of the central portion 34b and the inner wall 12a of the injection portion 12 can be prevented from sliding at high speed. In other words, it is important to provide a step on the anti-feeder side of the driver blade 34, and this can prevent damage to the central portion 34b of the driver blade 34. As a result, the durability of the driver blade 34 can be improved.

[0040] In the nail driver 10, at the top dead center position of the striking part 13, at least one of the tip part 34a and the base part 34c abuts against the inner wall 12a of the ejection part 12, and at the bottom dead center position of the striking part 13, either the tip part 34a or the base part 34c abuts against the inner wall 12a of the ejection part 12. For example, in the example of the state in which the striking part 13 has reached the top dead center shown in FIG. 2, the tip part 34a of the driver blade 34 is housed in the ejection part 12, and the tip part 34a abuts against the inner wall 12a of the ejection part 12. Therefore, in this state, it is possible to avoid the center part 34b of the driver blade 34 abutting against the inner wall 12a of the ejection part 12. 7, in the example where the striking portion 13 has reached the bottom dead center, the root portion 34c of the driver blade 34 is housed within the ejection portion 12, and the root portion 34c abuts against the inner wall 12a of the ejection portion 12. Therefore, even in this state, the center portion 34b of the driver blade 34 can be prevented from abutting against the inner wall 12a of the ejection portion 12.

[0041] In addition, in the state where the striking portion 13 shown in FIG. 7 reaches the bottom dead center, the tip portion 34a of the driver blade 34 protrudes by a length L from the injection portion 12. Therefore, by setting the relationship between the protruding length L of the tip portion 34a of the driver blade 34 from the injection portion 12 in the state where the striking portion 13 reaches the bottom dead center and the length L1 of the tip portion 34a of the driver blade 34 shown in FIG. 3 as L < L1, at least the tip portion 34a of the driver blade 34 can be accommodated in the injection portion 12 in the state where the striking portion 13 reaches the bottom dead center. Thereby, even in the state where the striking portion 13 reaches the bottom dead center, the tip portion 34a of the driver blade 34 can be brought into contact with the inner wall 12a of the injection portion 12, and the central portion 34b of the driver blade 34 can be prevented from contacting the inner wall 12a of the injection portion 12. However, in the state where the striking portion 13 reaches the bottom dead center, it is preferable that both the tip portion 34a and the root portion 34c of the driver blade 34 are accommodated in the injection portion 12 as shown in FIG. 7, whereby the central portion 34b of the driver blade 34 can be further prevented from contacting the inner wall 12a of the injection portion 12.

[0042] Also, as shown in FIG. 6, when the striking portion 13 is disposed between the top dead center position and the bottom dead center position, the tip portion 34a contacts the inner wall 12a of the injection portion 12. Thereby, even when the striking portion 13 is disposed between the top dead center position and the bottom dead center position, the central portion 34b of the driver blade 34 can be prevented from contacting the inner wall 12a of the injection portion 12. When the striking portion 13 is disposed between the top dead center position and the bottom dead center position, at least one of the tip portion 34a and the root portion 34c of the driver blade 34 may be accommodated in the injection portion 12.

[0043] As described above, in the nail driver 10 of the present embodiment, at least one of the tip portion 34a and the root portion 34c of the driver blade 34 may be accommodated in the injection portion 12 regardless of whether the striking portion 13 is disposed at the top dead center position, the bottom dead center position, or a position between the top dead center position and the bottom dead center position.

[0044] Next, modified examples of the driver blade of this embodiment will be described. The driver blade 34 of the first modified example shown in Fig. 9(a) and (b) has a shape in which the tip outer peripheral surface 34h on the opposite side to the feeder protrudes from the central outer peripheral surface 34j on the opposite side to the feeder, and the tip outer peripheral surface 34g on the feeder 46 side is recessed from the central outer peripheral surface 34i on the feeder 46 side. As for the outer peripheral surface 34f on the feeder 46 side, it is not necessary for the tip 34a and the central portion 34b to be flat surfaces of the same height as long as the tip outer peripheral surface 34g on the feeder 46 side does not protrude from the central outer peripheral surface 34i on the feeder 46 side at the central portion 34b. Even if the tip outer peripheral surface 34g on the feeder 46 side is recessed from the central outer peripheral surface 34i on the feeder 46 side as in the first modified example, the diameter of the central portion 34b is not excessively small, so that damage to the central portion 34b can be suppressed.

[0045] In the driver blade 34 of the second modification shown in Fig. 10(a) and (b), the outer peripheral surface 34h of the tip part on the opposite side to the feeder protrudes from the outer peripheral surface 34j of the central part on the opposite side to the feeder, and further, as shown in Fig. 11(a), a U-shaped groove part 34r is provided in the central part 34b on the opposite side to the feeder. This groove part 34r fits into the rail part 12c shown in Fig. 11(b) formed in the ejection part 12. That is, the groove part 34r fits into the rail part 12c of the ejection part 12, so that the vertical movement of the driver blade 34 is guided by the rail part 12c. In this driver blade 34, by providing a step part 34s in the groove part 34r on the opposite side to the feeder of the central part 34b, it is possible to prevent the groove part 34r of the central part 34b from being deteriorated due to friction with the rail part 12c. However, even if groove 34r in center portion 34b were to deteriorate, the driver blade 34 is unlikely to be damaged due to the characteristics of the impact when driving, so step 34s in groove 34r does not necessarily have to be provided.

[0046] The driver blade 34 of the third modification shown in Figures 12(a) and 12(b) has a shape in which a recess 34t is provided on the outer peripheral surface 34f of the center portion 34b on the opposite side to the feeder. As shown in Figures 13(a) and 13(b), the recess 34t is provided in an elongated shape only on the center portion 34b on the opposite side to the feeder, and is not provided on the tip portion 34a and the base portion 34c. Therefore, the center portion outer peripheral surface 34j on the opposite side to the feeder is recessed from the tip portion outer peripheral surface 34h on the feeder side because the recess 34t is provided.

[0047] The driver blade 34 of the fourth modification shown in Fig. 14(a) and (b) has a plurality of elongated vertical ribs 34u formed along the axial direction 34e on the outer peripheral surface 34f of the tip 34a on the opposite side to the feeder. As shown in Fig. 15(a) and (b), the vertical ribs 34u are provided only on the tip 34a on the opposite side to the feeder, and are not provided on the central portion 34b and the base portion 34c on the opposite side to the feeder. As a result, a part of the tip 34a on the opposite side to the feeder (the vertical ribs 34u) protrudes from the outer peripheral surface 34j of the central portion on the opposite side to the feeder. The vertical ribs 34u may also be provided on the base portion 34c.

[0048] The driver blade 34 of the fifth modification shown in Fig. 16(a) and (b) has a plurality of circumferential ribs 34v formed to cross the axial direction 34e on the arc-shaped portion of the outer peripheral surface 34f of the tip 34a on the opposite side to the feeder. As shown in Fig. 17(a) and (b), the circumferential ribs 34v are provided only on the tip 34a, and are not provided on the central portion 34b and the base portion 34c. As a result, a part of the tip 34a on the opposite side to the feeder (the circumferential rib 34v) protrudes from the outer peripheral surface 34j of the central portion on the opposite side to the feeder. The circumferential ribs 34v may also be provided on the base portion 34c.

[0049] The driver blade 34 of the sixth modified example shown in Figs. 18(a) and (b) has a plating film 34w formed on the arc-shaped portion of the outer peripheral surface 34f of the central portion 34b on the opposite side to the feeder. As shown in Figs. 19(a) and (b), the plating film 34w is formed only on the central portion 34b, and not on the tip portion 34a and the base portion 34c. There are two methods for forming such a plating film 34w. The first method is to use a base material for the driver blade 34 manufactured in the same shape as the embodiment shown in Figs. 3 and 4(a), (b), and (c), and to incorporate the driver blade 34 with the plating film 34w formed on the entire surface into a product. In the first method, as the ejection portion 12, the nail 16, and the driver blade 34 slide against each other during the actual nailing operation, the plating film 34w on the tip portion 34a and the base portion 34c peels off, and the plating film 34w automatically remains only on the opposite side to the feeder of the central portion 34b. On the other hand, the second method uses the same base material as in the first method, and forms a plating film 34w only on the opposite side of the center portion 34b to the feeder by masking the tip portion 34a and base portion 34c during plating.

[0050] In the driver blade 34 of the sixth modified example, as shown in Fig. 18(b), in the base material of the driver blade 34, the central outer peripheral surface 34j on the opposite side to the feeder is recessed from the tip outer peripheral surface 34h on the opposite side to the feeder shown in Fig. 18(a). That is, it is only necessary that the central outer peripheral surface 34j on the opposite side to the feeder of the base material of the driver blade 34 is recessed from the tip outer peripheral surface 34h and the base outer peripheral surface 34m of the base material, and the surface of the plating film 34w formed on the central portion 34b may protrude from or be recessed from the tip outer peripheral surface 34h and the base outer peripheral surface 34m on the opposite side to the feeder, or may be at the same height.

[0051] As described above, in the driver blades 34 of the first to sixth modified examples, at least a part of the outer peripheral surface 34f of either the tip portion 34a or the base portion 34c on the opposite side to the feeder protrudes from the outer peripheral surface 34f of the center portion 34b on the opposite side to the feeder. In other words, the outer peripheral surface 34f of the center portion 34b on the opposite side to the feeder is recessed from at least a part of the outer peripheral surface 34f of either the tip portion 34a or the base portion 34c on the opposite side to the feeder. This makes it possible to prevent the outer peripheral surface 34f of the center portion 34b on the opposite side to come into contact with the inner wall 12a of the injection portion 12.

[0052] As a result, the durability of driver blade 34 can be improved in driver blades 34 of the first to sixth modified examples as well.

[0053] The present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the present invention. For example, in the above embodiment, the first portion of the driver blade 34 is the tip portion 34a, the second portion is the central portion 34b, and the first portion is disposed on one side (the stopper protruding side) of the second portion in the axial direction 34e. However, the first portion and the second portion may be disposed at different positions in the axial direction 34e of the driver blade 34. Therefore, the first portion may be disposed on the other side (the opposite side to the stopper protruding side) of the axial direction 34e of the second portion. In this case, the same effect as the above embodiment can be obtained, that is, the outer peripheral surface 34f on the opposite feeder side of the central portion 34b can be prevented from contacting the inner wall 12a of the injection portion 12, thereby improving the durability of the driver blade 34. In addition, with regard to the arc-shaped tip outer peripheral surface 34h and the arc-shaped base outer peripheral surface 34m, taking into consideration the characteristics of the impact when driving in, there are parts that are unlikely to cause damage to the driver blade 34 even if deterioration occurs, so they may not protrude; in other words, only a portion in the circumferential direction may be configured to protrude beyond the arc-shaped central outer peripheral surface 34j. [Explanation of symbols]

[0054] 10... nail gun (working machine), 11... housing, 12... ejection portion, 12a... inner wall, 12b... U-groove, 12c... rail portion, 13... striking portion, 14... trigger, 15... push lever, 16... nail (fastener), 17... mating member, 18... body portion, 19... handle, 20... head cover, 21... plug, 22... cylinder, 23... accumulator chamber, 24... passage, 25... sealing member, 26... exhaust valve chamber, 27... mount portion, 28... passage, 29... passage, 30... exhaust valve, 31... valve seat, 32... piston upper chamber, 33... piston, 34... driver blade, 34a... tip portion (first portion), 34b... center portion ( 2nd part), 34c...base part (3rd part), 34d...axis, 34e...axial direction, 34f...outer peripheral surface, 34g, 34h...tip part outer peripheral surface, 34i, 34j...center part outer peripheral surface, 34k, 34m...base part outer peripheral surface, 34n...lower end surface, 34p...tapered part, 34q...striking surface, 34r...groove part, 34s...step part, 34t...recess, 34u...vertical rib, 34v...circumferential rib, 34w...plating film, 35...lower piston chamber, 36...return air chamber, 37, 38...passage, 39...bumper, 40...shaft hole, 41...check valve, 42...spring, 43...ejection path, 44...stopper, 45...magazine, 46...feeder (supply part), 47...spring

Claims

1. a striking portion formed in a rod shape extending about an axis and moving to one side in the axial direction to strike the fastener; an ejection portion that contacts an outer peripheral surface of the striking portion to guide the movement of the striking portion to the one side in the axial direction; a supply unit that supplies the stopper to the injection unit by biasing the stopper to one side in a direction intersecting the axial direction; Equipped with The striking part is a supply portion side outer peripheral surface that forms a straight portion of a cross section in a direction perpendicular to the axial direction; a counter-supply part side outer peripheral surface that is not included in the supply part side outer peripheral surface; The rotor includes a first portion, a second portion, and a third portion that are provided at different positions in the axial direction, the supply part side outer peripheral surfaces of the first portion and the third portion do not protrude beyond the supply part side outer peripheral surface of the second portion, and at least a part of the counter supply part side outer peripheral surfaces of the first portion and the third portion protrude beyond the counter supply part side outer peripheral surface of the second portion, the second portion is located between the first portion and the third portion, The first portion abuts against the ejection portion at a top dead center position of the striking portion, A work machine, wherein either the first portion or the third portion abuts against the ejection portion when the impact portion is at a bottom dead center position.

2. The work machine according to claim 1 , wherein the first portion abuts against the ejection portion when the impact portion is disposed at the top dead center position, the bottom dead center position, or between the top dead center position and the bottom dead center position.

3. a lower end surface of the striking portion including a striking surface that strikes the fastener, 3. The work machine according to claim 1, wherein the striking surface is formed at an angle with respect to the axis so that the striking surface on the supplying portion side protrudes toward the one side in the axial direction from the side opposite to the supplying portion.

4. The work machine according to claim 1 , wherein the first portion and the second portion have similar shapes when cut in a direction perpendicular to the axial direction.

5. 5. The work machine according to claim 1, wherein the supply section presses another fastener against the striking section in a direction intersecting with the axial direction during the process in which the striking section strikes the fastener.

6. The work machine according to claim 1 , wherein the amount of protrusion of the first portion relative to the second portion is equal to or greater than 0.05% and less than 0.5% of a length of the second portion in the axial direction.

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