Driving tools

Abstract

To provide a driving tool that is driven into by moving a driver by gas pressure, and is engaged with a wheel of a lift mechanism to return the driver from a lower movable end to a position of an upper movable end, in which a relative position of the wheel with respect to the driver is sometimes shifted by clogging of nails or the like and therefor a configuration thereof in which some of engagement parts are released by making the driver interfere with parts to be engaged at the time of starting lift operation impairs durability, which is configured to return the engagement to a normal engagement state by avoiding the interference while securing the durability in order to solve the above-described problem.SOLUTION: A driving tool comprises a displacement allowing mechanism 27 that allows a wheel 22 to be displaced in a radial direction with respect to a rotary shaft 21, and a displacement restricting mechanism 40 that restricts the wheel 22 from being displaced in the radial direction. In an initial stage of lift operation, in which a first engagement part P1 is engaged by rotation of the wheel 22 with a part L to be engaged, a displacement restricted state of the wheel 22 by the displacement restricting mechanism is released, so that the whole of the wheel 22 is brought into a state where the wheel as a whole can be displaced in the radial direction.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present disclosure relates to a driving tool for driving a driving tool such as a nail or staple into wood or the like. [Background technology]

[0002] Patent Documents 1 and 2 disclose 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 within a cylinder, and a driver that is connected to the piston and moves downward as a unit to strike the driving tool. The piston and driver move downward in the driving direction due to the gas pressure in the pressure accumulator. The piston and driver are returned in the opposite direction to the driving direction by a lift mechanism.

[0003] The lift mechanism has a wheel with multiple engaging portions that engage with engaged portions provided on the driver. The wheel is rotated by an electric motor. After a driving operation, the wheel rotates and the engaging portions sequentially mesh with the engaged portions of the driver, moving the driver upward in the direction opposite to the driving operation. As the piston moves upward in the direction opposite to the driving operation, the gas pressure in the accumulator chamber increases. As the lift mechanism disengages from the driver that has been moved upward to its uppermost position, the driver is moved downward by the gas pressure, performing a striking operation.

[0004] Patent Document 1 discloses a technique for reducing the load on the engaged portion of the driver or the engaging portion of the lift mechanism. According to the technique of Patent Document 1, the load is reduced by displacing the engaging portion (final pin) of the lift mechanism, which engages with the engaged portion of the driver at the upper end of its travel, in the counter-engagement direction. Patent Document 2 discloses a technique for dealing with a situation in which the relative position of the engaging portion of the lift mechanism with respect to the engaged portion of the driver is shifted due to, for example, nail jamming. According to the technique of Patent Document 2, interference of the engaging portion with the engaged portion of the driver is avoided by displacing the engaging portion (first pin), which is first engaged when the driver starts to lift, in the counter-engagement direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 059666 [Patent Document 2] International Publication No. 2016 / 199670 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Documents 1 and 2 disclose a configuration in which some of the multiple engagement parts of the lift mechanism (the final pin, the first pin) are always displaceable. Such a configuration complicates the detailed configuration of the lift mechanism, reducing its durability and potentially causing malfunctions. The present disclosure aims to ensure good operation of the lift mechanism without compromising its durability. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, the driving tool includes a piston that moves in the driving direction, for example, by gas pressure, and a driver that moves integrally with the piston in the driving direction and strikes the driving tool. The driving tool also includes a lift mechanism that moves the driver in the counter-driving direction, for example. The driver includes, for example, multiple engaged portions along the longitudinal direction. The lift mechanism includes, for example, a rotation shaft and a wheel that rotates together with the rotation shaft around the rotation shaft. The lift mechanism includes, for example, multiple engaging portions arranged along the outer periphery of the wheel and engaging with the engaged portions of the driver. The lift mechanism includes, for example, a displacement allowing mechanism that allows radial displacement of the wheel relative to the rotation shaft. The lift mechanism includes, for example, a displacement restricting mechanism that restricts radial displacement of the wheel. The multiple engaging portions include a first engaging portion that first engages with the engaged portion when the lift mechanism moves the driver in the counter-driving direction, and a second engaging portion that secondly engages with the engaged portion. When the first engaging portion engages with the engaged portion, the displacement restricting mechanism releases the wheel from displacement restriction.

[0008] Therefore, the radial displacement of the wheel prevents the first engaging portion of the driver from interfering with the engaged portion (a state in which the first engaging portion is not engaged with the underside of the engaged portion). As a result, even if, for example, the driver is stopped before the end of its downward movement in the driving direction due to a nail jam, and as a result the first engaging portion of the wheel does not engage with the underside of the engaged portion, resulting in an interference state, the radial displacement of the wheel prevents the interference and the engaging portion engages with the underside of the engaged portion. The rotation of the wheel in the engaged state moves the driver upward.

[0009] The entire wheel is displaced in the radial direction, separating the engaging portion from the engaged portion. This avoids complicated details compared to a configuration in which only some of the engaging portions are displaced. Furthermore, for example, when the first engaging portion receives a reaction force from the engaged portion of the driver in the anti-engagement direction with a force greater than a predetermined force due to the above-mentioned interference state, the displacement allowance mechanism allows the wheel to be displaced in the radial direction. The excessive reaction force caused by the interference is absorbed by the wheel being displaced in the radial direction, and the normal engagement state of the first engaging portion with the engaged portion is restored. Conversely, by restricting the radial displacement of the wheel by the displacement restriction mechanism, malfunctions can be more reliably avoided compared to a configuration in which displacement of each engaging portion is always permitted. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a perspective view of a lift mechanism and a displacement allowance mechanism according to the first embodiment. [Figure 4] 1 is a vertical cross-sectional view of a lift mechanism and a displacement allowance mechanism according to Example 1. This figure shows a displacement allowance state in which radial displacement of an engagement portion is allowed. [Figure 5] 1 is a vertical cross-sectional view of a lift mechanism and a displacement allowance mechanism according to Example 1. This figure shows a displacement restricted state in which radial displacement of an engagement portion is restricted. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. 4, and is a plan view of a rotating cam. [Figure 7] This is an exploded view of the cam mechanism, showing the state in which the cam top of the rotating cam engages with the cam recess of the fixed cam and the rotating cam is raised. [Figure 8] 1 is a development view of the cam mechanism, showing the state in which the fixed cam is disengaged from the cam recess and the rotating cam moves downward. [Figure 9] 1 is a vertical cross-sectional view of the main body, showing the standby state. [Figure 10] 1 is a vertical cross-sectional view of the main body, showing the driver at its upper end. [Figure 11] 1 is a vertical cross-sectional view of the main body, showing the driver at its lowest position. [Figure 12] 10 is a longitudinal cross-sectional view of the main body, showing a locked state in which the driver is stopped at a lock position before the lower end of the drive shaft. [Figure 13] 13 is a partially enlarged view of FIG. 12. This figure shows the state in which the engaging portion is engaged with the engaged portion when the driver is in the locked state. This figure shows the state in which the first engaging portion interferes with the third engaged portion. [Figure 14] This figure shows the state in which the engaging portion engages with the engaged portion when the driver is in the locked state. This figure shows the state in which the wheel is displaced in the radial direction when the third engaged portion applies a predetermined or greater external force to the first engaging portion. [Figure 15] 10 shows an engaging state of an engaging portion with respect to an engaged portion when the driver is in a locked state, in which a first engaging portion is engaged with a second engaged portion. [Figure 16] 10 is a longitudinal cross-sectional view of the main body, showing a displacement-restricted state in which the locking member has entered the insertion hole. [Figure 17] FIG. 10 is a perspective view of a lift mechanism according to a second embodiment. [Figure 18] FIG. 10 is an exploded perspective view of a lift mechanism according to a second embodiment. [Figure 19]10 is a cross-sectional view of a lift mechanism according to a second embodiment, showing a locked state in which the driver is stopped at a locked position before the lower end of movement. [Figure 20] 10 is a cross-sectional view of a lift mechanism according to a second embodiment, showing a state in which a wheel is displaced in the radial direction. [Figure 21] 21 is a cross-sectional view taken along the line XXI-XXI in FIG. 20, showing a vertical cross-sectional view of the lift mechanism. [Figure 22] This is a cross-sectional view of the lift mechanism taken along the line XXII-XXII in Figure 21. This view shows a state in which radial displacement of the wheel is permitted. [Figure 23] 23 is a cross-sectional view of the lift mechanism taken along the line XXIII-XXIII in Fig. 21. This view shows a state in which the restricting member has come off the restricting wall portion and reached the release portion. [Figure 24] 10 is a cross-sectional view of a lift mechanism according to a second embodiment, showing a state in which a first engaging portion is engaged with a second engaged portion. [Figure 25] 10 is a cross-sectional view of a lift mechanism according to a second embodiment, showing a state in which radial displacement of a wheel is restricted. [Figure 26] 10 is a cross-sectional view of a lift mechanism according to a second embodiment, showing a state in which a regulating member moves along a regulating wall portion. DETAILED DESCRIPTION OF THE INVENTION

[0011] In one or more embodiments, the displacement of the wheel in the radial direction is restricted by the displacement restriction mechanism, for example, at the stage when the second engaging portion engages with the engaged portion.

[0012] Therefore, when the second engaging portion engages with the engaged portion of the driver, the radial displacement of the wheel is restricted by the displacement restriction mechanism. Therefore, radial displacement of the wheel is permitted only when the first engaging portion engages with the engaged portion of the driver. The wheel is permitted to displace radially and escape in the anti-engagement direction only for the first engaging portion where an abnormal engagement state of the engaging portion with the engaged portion of the driver is assumed. When an engaging portion other than the first engaging portion engages with the engaged portion, radial displacement of the wheel is restricted, thereby reliably avoiding malfunctions.

[0013] In one or more embodiments, the radial displacement of the wheel may be restricted at the stage when the direction of displacement of the wheel relative to the axis of rotation becomes parallel to the direction of movement of the driver at the latest.

[0014] Therefore, at the stage where the direction of the force received from the driver (driver movement direction) coincides with the displacement direction relative to the wheel rotation axis, the engagement portion receives a large external force (thrust due to gas pressure) in the wheel displacement direction from the driver. At the latest at this stage, the wheel displacement is restricted by the displacement restriction mechanism. This maintains a good engagement state of the lift mechanism with the driver, preventing malfunctions. At the stage where the wheel displacement direction is inclined with respect to the driver's movement direction, the external force applied by the driver to the wheel in the wheel displacement direction becomes smaller. At the latest at the stage where the wheel displacement direction becomes parallel to the driver's movement direction with respect to the wheel rotational movement, radial displacement of the wheel is restricted, thereby maintaining a good engagement state while receiving a large external force.

[0015] In one or more embodiments, the displacement allowing mechanism may include a through hole formed in the wheel. The through hole may be elongated in the radial direction so as to allow radial displacement of the wheel relative to a rotation shaft inserted into the through hole. The displacement restricting mechanism may include a locking member that restricts radial displacement of the wheel by entering the through hole.

[0016] Therefore, the locking member is inserted between the insertion hole of the wheel and the rotation shaft supporting the wheel, restricting radial displacement of the wheel relative to the rotation shaft. When the locking member is withdrawn from the insertion hole, radial displacement of the wheel relative to the rotation shaft is permitted. By moving the locking member forward and backward relative to the insertion hole, the wheel is switched between a state in which radial displacement is permitted and a state in which radial displacement is restricted.

[0017] In one or more embodiments, the locking member is displaced, for example, in the axial direction of the rotation shaft, to advance and retreat into and from the insertion hole. Therefore, the locking member can be advanced and retreated into and from the insertion hole with a simple configuration.

[0018] In one or more embodiments, the locking member is located, for example, on the inner circumferential side of the engaging portion, thereby making the displacement restriction mechanism more compact.

[0019] In one or more embodiments, for example, a cam mechanism is provided that moves the locking member forward and backward relative to the insertion hole as the wheel rotates. Thus, the locking member advances into the insertion hole in conjunction with the rotation of the wheel. Also, the locking member retreats from the insertion hole in conjunction with the rotation of the wheel.

[0020] In one or more embodiments, for example, a hole wall surface constituting the insertion hole has a pair of sliding surfaces that are parallel to each other and extend in the radial direction. The rotating shaft has a pair of support planes that face the pair of sliding surfaces and extend in the radial direction. The sliding surfaces of the insertion hole are in sliding contact with the support surfaces of the rotating shaft, so that the power of the rotating shaft is transmitted to the wheel and rotates integrally with it, and the wheel is supported so as to be displaceable in the radial direction relative to the rotating shaft.

[0021] In one or more embodiments, the mechanism includes a biasing member mounted within the insertion hole. The biasing member biases the wheel in a direction in which the engaging portion of the wheel engages with the engaged portion of the driver. The biasing member therefore maintains the engaged state between the engaging portion and the engaged portion. By mounting the biasing member within the insertion hole, the displacement allowance mechanism can be made more compact.

[0022] In one or more embodiments, the displacement restriction mechanism has, for example, a biasing member that biases the locking member in a direction that causes the locking member to retract from the insertion hole. Therefore, the locking member is reliably retracted from the insertion hole with a simple configuration.

[0023] In one or more embodiments, for example, the cam mechanism has a plurality of cam portions spaced unequally about the axis of the rotary shaft. All of the plurality of cam portions engage with the cam receiving side at one location about the axis of the rotary shaft. This fixes the movement of the locking member toward and away from the insertion hole at one location about the axis of the rotary shaft. Therefore, the state in which radial displacement of the wheel is permitted and the state in which it is restricted are reliably achieved at one fixed location about the axis of the rotary shaft. This maintains a good engagement state of the lift mechanism with the driver.

[0024] In one or more embodiments, for example, the displacement allowance mechanism has an insertion hole formed in the wheel. The insertion hole has a shape that is elongated in the radial direction so as to allow radial displacement of the wheel relative to, for example, a rotation shaft inserted into the insertion hole. For example, the displacement restriction mechanism has a restriction member provided on the wheel, a restriction wall portion provided along the periphery of the wheel that restricts radial displacement of the restriction member, and a restriction release portion that releases the restriction state imposed by the restriction wall portion.

[0025] Therefore, the radial displacement of the restricting member is restricted by the restricting wall portion, thereby restricting the radial displacement of the wheel relative to the rotational axis. When the restricting member is disengaged from the restricting wall portion, the radial displacement of the wheel relative to the rotational axis is permitted. Depending on the presence or absence of the restricting wall portion restricting the radial displacement of the restricting member, the radial displacement of the wheel can be switched between being permitted and being restricted.

[0026] In one or more embodiments, for example, the restricting member protrudes from both sides of the wheel in the axial direction. Therefore, the restricting member is guided by the restricting wall portion on both sides of the wheel in the axial direction. This ensures stable rotation of the wheel and clearly switches between a state in which radial displacement of the wheel is permitted and a state in which it is restricted.

[0027] In one or more embodiments, for example, both ends of the engagement portion protrude on both axial sides of the wheel, and the restricting member is provided using the protruding portions of the engagement portion. Therefore, by providing the restricting member using the engagement portion, the configuration can be simplified.

[0028] In one or more embodiments, for example, the restricting member is disposed on the opposite side of the rotation axis from the first engaging portion. Therefore, the displacement direction of the wheel is set in a direction in which the first engaging portion moves away from the engaged portion of the driver. As a result, when the first engaging portion engages with the engaged portion, the wheel becomes displaceable in the radial direction, thereby preventing interference of the first engaging portion with the engaged portion.

[0029] In one or more embodiments, the restricting member is provided with a roller body that is rotatable about an axis, thereby ensuring smooth movement of the restricting member along the restricting wall, thereby ensuring smooth rotation of the wheel. [Example]

[0030] FIG. 1 shows, as an example of a driving tool 1, a gas spring type driving tool that uses the gas pressure in the upper chamber of a cylinder as a thrust for driving a driving tool N. In the following explanation, as shown in each figure, the driving direction of the driving tool N is defined as downward, and the opposite driving direction is defined as upward. A driver 15, which will be described below, moves downward to drive the driving tool N, and after driving, the driver 15 is returned upward. A user of the driving tool 1 is positioned generally on the left side of the driving tool 1 in FIG. 1. The side in front of the user is defined as the rear side (user side), and the front is defined as the front side. Furthermore, left and right directions are based on the user.

[0031] As shown in Figures 1, 2, and 9, the driving tool 1 has a main body 10. The main body 10 has a configuration in which a cylinder 12 is housed inside a generally cylindrical main body housing 11. A piston 13 is housed inside the cylinder 12 so that it can reciprocate up and down. The upper part of the cylinder 12 is connected to a pressure accumulator chamber 14. Gas pressure in the pressure accumulator chamber 14 acts on the upper surface of the piston 13 as a thrust for striking.

[0032] A long driver 15 is connected to the underside of the piston 13. The driver 15 extends downward. The lower side of the driver 15 enters the driving passage 2a of the driving nose 2 provided on the underside of the main body 10. The gas pressure of the pressure accumulator chamber 14 acting on the upper surface of the piston 13 causes the driver 15 to move downward within the driving passage 2a, striking one driving tool N. The struck driving tool N is ejected from the ejection port 2b of the driving nose 2. The ejected driving tool N is driven into the workpiece W. A lower moving end damper 16 is arranged at the bottom of the cylinder 12 to absorb impact at the lower moving end of the piston 13.

[0033] A grip unit 3 that is held by the user is provided on the side of the main body 10. A switch lever 3a that is pulled by the user with the fingertip is provided on the underside of the front of the grip unit 3. A battery attachment unit 4 is provided at the rear of the grip unit 3. A battery pack 5 is attached to the battery attachment unit 4. The drive unit 30, which will be described later, operates using the power of the battery pack 5 as its power source.

[0034] A magazine 6 is connected to the driving nose 2. A large number of driving tools N loaded in the magazine 6 are supplied one by one into the driving passage 2a.

[0035] A lift mechanism 20 is connected to the side of the driving nose 2. The lift mechanism 20 has the function of returning the piston 13 and the driver 15 together upward after striking. When the lift mechanism 20 returns the piston 13 upward, the gas pressure in the pressure accumulator chamber 14 is increased.

[0036] A drive unit 30 is provided alongside the lift mechanism 20. The lift mechanism 20 is operated by the drive unit 30. The drive unit 30 is housed in a drive unit case 31 that straddles the lift mechanism 20 and the lower part of the battery attachment part 4 in a generally L-shape. The drive unit case 31 is provided integrally with the main body housing 11. The lift mechanism 20 is also covered by the drive unit case 31.

[0037] The drive unit 30 has an electric motor 32 as a drive source. The electric motor 32 is housed with the axis of its output shaft 32a (motor axis J) oriented along the front-to-rear direction perpendicular to the driving direction (the direction perpendicular to the paper surface in FIG. 2). The electric motor 32 is powered by electricity from the battery pack 5. As described above, the electric motor 32 is started by pulling the switch lever 3a.

[0038] An output shaft 32a of the electric motor 32 is rotatably supported by a motor housing 32b via bearings 32c and 32d. The output shaft 32a is connected to a reduction gear train 33. A cylindrical mechanism case 25 is connected to the front part of the motor housing 32b. The reduction gear train 33 is supported on the inner peripheral side of the mechanism case 25. The reduction gear train 33 uses a three-row planetary gear train. The three-row planetary gear trains are arranged coaxially with one another and coaxially with the motor axis J. The rotational output of the electric motor 32 is reduced in speed by the reduction gear train 33, which includes the three-row planetary gear train, and is output to the lift mechanism 20.

[0039] The lift mechanism 20 has a rotating shaft 21 connected to the reduction gear train 33 and a wheel 22 supported by the rotating shaft 21. The rotating shaft 21 is rotatably supported on the inner periphery of a mechanism case 25 via front and rear bearings 23, 24. The rotation axis of the rotating shaft 21 coincides with the motor axis J. A displacement restriction mechanism 40 is connected to the front side of the lift mechanism 20. The front part of the mechanism case 25, in front of the displacement restriction mechanism 40, is closed by a lid 25a. The front bearing 23 is held by the mechanism case 25 via the lid 25a. The rear bearing 24 is held by the bottom of the mechanism case 25.

[0040] When the electric motor 32 is started, the wheel 22 of the lift mechanism 20 rotates integrally. As shown in Figures 2, 3, 4, and 5, the wheel 22 has two flange portions 22a that are parallel to each other and spaced apart by a fixed distance. A plurality of engagement portions P are provided across the periphery of the two flange portions 22a and supported at both ends. In this embodiment, as shown in Figure 9, there are, for example, ten engagement portions P (P1 to P10). Each engagement portion P uses a cylindrical shaft member (pin).

[0041] The multiple engagement portions P are provided within a certain range in the circumferential direction of the wheel 22. In this embodiment, ten engagement portions P are arranged at equal intervals within a range of approximately 3 / 4 of the circumference. No engagement portions P are arranged in the remaining circumferential range. Hereinafter, the circumferential range in which no engagement portions P are arranged will be referred to as the escape portion 26. The left side of the wheel 22 enters the driving passage 2a through a window portion 25b provided in the mechanism case 25. Within the driving passage 2a, each engagement portion P of the wheel 22 engages with the engaged portion L of the driver 15.

[0042] A plurality of engaged portions L are provided on the right side of the driver 15. In this embodiment, ten engaged portions L are arranged at regular intervals in the longitudinal direction (vertical direction) of the driver 15. Each engaged portion L has a rack-tooth shape and is provided so as to protrude laterally. When each engaging portion P of the wheel 22 is engaged with the engaged portion L of the driver 15, the wheel 22 rotates, causing the driver 15 and piston 13 to return upward. When the electric motor 32 is activated, the wheel 22 rotates counterclockwise as shown by the arrow in Figures 9, 10, and 11.

[0043] 9 shows the standby state of the main body 10. In the standby state, the driver 15 and piston 13 are held slightly below the upper moving end. In this standby state, the engaging portion P immediately before the relief portion 26 engages with the underside of the engaged portion L at the lowest end of the driver 15. Hereinafter, the engaging portion P immediately before the relief portion 26 will be specifically referred to as the final engaging portion P10. The engaged portion L at the lowest end of the driver 15 will be specifically referred to as the final engaged portion L10.

[0044] In the standby state, the electric motor 32 is started by pulling the switch lever 3a. When the electric motor 32 starts and the wheel 22 rotates counterclockwise, the piston 13 and the driver 15 move further upward together from the standby position due to the engagement of the final engaging portion P10 with the final engaged portion L10. As a result, the piston 13 and the driver 15 reach the upper limit of their movement, as shown in Figure 10, just before driving.

[0045] In the state immediately before driving, the final engaging portion P10 is about to disengage from the final engaged portion L10. As the wheel 22 continues to rotate counterclockwise, the final engaging portion P10 disengages from the final engaged portion L10. This causes the piston 13 and the driver 15 to move downward due to the gas pressure in the pressure accumulator chamber 14. As the driver 15 moves downward within the driving passage 2a, one driving tool N is struck. When the driver 15 moves downward, all of the engaging portions P of the wheel 22 are removed from the driving passage 2a and positioned within the mechanism case 25. This results in the relief portions 26 of the wheel 22 being positioned within the driving passage 2a. This prevents the engaging portions P from interfering with the engaged portion L of the driver 15, ensuring a smooth driving operation.

[0046] After the driving tool N strikes, the wheel 22 continues to rotate counterclockwise with the driver 15 reaching its lowermost position. As a result, as shown in Figure 11, the engaging portion P immediately after the relief portion 26 in the rotational direction of the wheel 22 engages with the underside of the engaged portion L at the top of the driver 15. Hereinafter, the engaging portion P immediately after the relief portion 26 will be referred to as the first engaging portion P1. The engaged portion L at the top of the driver 15 will be referred to as the first engaged portion L1.

[0047] With the first engaging portion P1 engaged with the first engaged portion L1, the wheel 22 continues to rotate counterclockwise. This causes the second engaging portion P2 to engage with the underside of the second engaged portion L2, and then the third engaging portion P3 to engage with the underside of the third engaged portion L3. As the wheel 22 continues to rotate, the fourth engaging portion P4, fifth engaging portion P5, sixth engaging portion P6, seventh engaging portion P7, eighth engaging portion P8, ninth engaging portion P9, and final engaging portion P10 sequentially engage with the undersides of the fourth engaged portion L4, fifth engaged portion L5, sixth engaged portion L6, seventh engaged portion L7, eighth engaged portion L8, ninth engaged portion L9, and final engaged portion L10, thereby moving the driver 15 and piston 13 upward. When the final engaging portion P10 engages with the underside of the final engaged portion L10, the driver 15 and piston 13 reach the standby position described above. For example, by appropriately controlling the time from the start of the electric motor 32, the electric motor 32 is stopped when the driver 15 and the piston 13 reach the standby position. This completes the series of driving operations.

[0048] If the nail driver N struck by the downward movement of the driver 15 is not properly driven into the workpiece W, a deformed nail driver N may become stuck in the driving passage 2a, resulting in a jammed nail or insufficient nail driving. In this case, as shown in Figure 12, the driver 15 stops at a higher position than the downward limit indicated by the two-dot chain line. The wheel 22 continues to rotate even when the driver is stopped. This causes a shift in the relative position of the engaging portion P of the driver 15 with respect to the engaged portion L.

[0049] 12 and 13, a state occurs in which the first engaging portion P1 does not enter the lower surface of the first engaged portion L1 and interferes with the third engaged portion L3. The lift mechanism 20 of this embodiment is equipped with a displacement allowance mechanism 27 for absorbing deviation of the engaging portion P from the position at which it can enter the lower surface of the engaged portion L. The displacement allowance mechanism 27 has an insertion hole 28 provided in the wheel 22. A pair of sliding surfaces 28a that are parallel to each other and extend radially are provided on the inner wall surface of the insertion hole 28. The insertion hole 28 is formed in the shape of a radially elongated hole to allow radial displacement of the wheel 22 relative to the rotation shaft 21. The rotation shaft 21 is inserted into the insertion hole 28. The rotation shaft 21 is provided with a pair of support planes 21a that extend radially and face the sliding surfaces 28a.

[0050] The slide surface 28a is in sliding contact with the support flat surface 21a of the rotating shaft 21, so that the wheel 22 is supported so as to be rotatable integrally with the rotating shaft 21 and so as to be displaceable within a certain range in the radial direction. The wheel 22 is displaced radially relative to the rotating shaft 21, so that interference between the engaging portion P and the engaged portion L of the driver 15 is avoided. A compression spring 29 is interposed between the inner wall surface of the insertion hole 28 and the rotating shaft 21. The biasing force of the compression spring 29 biases the wheel 22 toward the engaging side, which brings the engaging portion P closer to the engaged portion L of the driver 15. Therefore, radial displacement of the wheel 22 toward the non-engaging side is performed against the biasing force of the compression spring 29.

[0051] 14, when the external force F of the sliding direction component that the first engaging portion P1 receives from the third engaged portion L3 of the driver 15 due to rotation of the wheel 22 becomes greater than the biasing force of the compression spring 29, the entire wheel 22 is displaced in the radial direction against the compression spring 29. This prevents interference of the first engaging portion P1 with the third engaged portion L3 (interlocked state). By preventing interference of the engaging portion P of the wheel 22 with the engaged portion L of the driver 15, the wheel 22 continues to rotate smoothly.

[0052] As the wheel 22 rotates while displacing in a direction away from the driver 15, the first engaging portion P1 passes beside the third engaged portion L3. At this stage, the external force F in the sliding direction received from the third engaged portion L3 decreases. Therefore, as shown in FIG. 15 , the wheel 22 is returned in a direction approaching the driver 15 by the biasing force of the compression spring 29. As the wheel 22 rotates while being returned, the first engaging portion P1 abuts against the lower surface of the second engaged portion L2. As will be described later, at this stage, the locking member 41 is inserted into the insertion hole 28, and the wheel 22 is switched to a state in which radial displacement thereof is restricted.

[0053] The timing for returning the wheel 22 from a state in which radial displacement is permitted to a state in which radial displacement is restricted can be set to the point in time when the first engaging portion P1 is normally engaged with the engaged portion L of the driver 15 as described above, but can also be changed as appropriate. For example, the timing may be configured to switch to the restricted state when the second engaging portion P2 engages with the engaged portion L.

[0054] With the first engaging portion P1 properly engaged with the engaged portion L, the wheel 22 continues to rotate, displacing the driver 15 upward from the stopped position. When the driver 15 is raised to the standby position by the rotation of the wheel 22, the electric motor 32 is stopped. This prevents the driver 15 from moving downward, making it easy to remove the jammed driving tool N from the driving passage 2a.

[0055] In this embodiment, the radial displacement of the wheel 22 by the displacement allowing mechanism 27 is permitted within a certain range before and after the first engaging portion P1 engages with the engaged portion L. When the second to final engaging portions (P2 to P10) engage with the engaged portion L of the driver 15, the radial displacement of the wheel 22 is restricted by the displacement restricting mechanism 40. Details of the displacement restricting mechanism 40 are shown in FIGS. 3 to 8.

[0056] The displacement restriction mechanism 40 has one locking member 41. A cylindrical shaft member is used for the locking member 41. As shown in FIGS. 5, 8, and 16, the locking member 41 is inserted into the gap between the inner wall surface of the insertion hole 28 and the rotation shaft 21, thereby restricting radial displacement of the wheel 22 relative to the rotation shaft 21. As shown in FIGS. 4 and 7, the locking member 41 is withdrawn from the insertion hole 28, thereby allowing radial displacement of the wheel 22 relative to the rotation shaft 21.

[0057] The locking member 41 moves along the axial direction of the rotating shaft 21 (the direction of the motor axis J), thereby advancing and retreating relative to the insertion hole 28. The advancing and retreating movement of the locking member 41 relative to the insertion hole 28 is controlled by a cam mechanism 42. The cam mechanism 42 has a disk-shaped rotating cam 43 and a disk-shaped fixed cam 44. The rotating cam 43 and the fixed cam 44 are supported coaxially on the rotating shaft 21.

[0058] As shown in FIG. 6, the rotary shaft 21 is inserted into the support hole 43a of the rotary cam 43. Two flat receiving surfaces 43b are provided parallel to each other on the inner wall surface of the support hole 43a. The rotary shaft 21 is provided with two flat support surfaces 21b facing the two receiving surfaces 43b. The rotary cam 43 is supported on the rotary shaft 21 with the two receiving surfaces 43b in sliding contact with the support surfaces 21b. As a result, the rotary cam 43 is rotatable integrally with the rotary shaft 21 around the motor axis J and is supported so as to be displaceable in the direction of the motor axis J relative to the rotary shaft 21. As shown by arrow R in FIG. 6, the rotary cam 43 rotates counterclockwise. In the figure, the rotational direction of the rotary shaft 21, wheel 22, and rotary cam 43 is indicated by arrow R.

[0059] As shown in Figures 4, 5, and 6, one locking member 41 is provided integrally with the rotating cam 43. The locking member 41 is provided so as to protrude downward from the underside of the rotating cam 43. The locking member 41 protrudes parallel to the motor axis J. The locking member 41 is disposed on the inner peripheral side of the engaging portion P of the wheel 22. The locking member 41 revolves integrally with the rotating cam 43 around the motor axis J and moves integrally with the rotating cam 43 in the direction of the motor axis J.

[0060] For example, three compression springs 45 are arranged equally spaced in the circumferential direction between the lower surface of the rotating cam 43 and the upper surface of the wheel 22. The compression springs 45 are shown in Figures 2 and 4. The biasing force of the compression springs 45 biases the rotating cam 43 in a direction (upward) approaching the fixed cam 44. As a result, the locking member 41 is biased in a direction retracting from the insertion hole 28.

[0061] As shown in FIG. 6, three cam portions C1, C2, and C3 are provided along the periphery of the upper surface of the rotating cam 43. Each of the three cam portions C1, C2, and C3 has one flat cam crest, one flat cam valley, and a lift portion that guides the movement between the cam crest and the cam valley. The three cam crests 43c, 43d, and 43e are unequally spaced around the motor axis J at intervals of, for example, 110°, 120°, and 130°. The three cam crests 43c, 43d, and 43e have different lengths of their rotational regions (circumferential regions). The circumferential regions of the first cam crest 43c and the second cam crest 43d are shorter than those of the third cam crest 43e. The circumferential region of the third cam crest 43e is the longest. The circumferential regions of the first cam crest 43c and the second cam crest 43d are set to approximately the same length.

[0062] Lift portions 43f, 43g, and 43h are provided on the front side of the first to third cam apexes 43c, 43d, and 43e in the rotational direction to guide the fixed cam 44 to each cam apex 43c, 43d, and 43e. The circumferential regions of the three lift portions 43f, 43g, and 43h are set to the same length. This makes the inclination angles of the three lift portions 43f, 43g, and 43h uniform. Furthermore, the three lift portions 43f, 43g, and 43h are arranged unequal in the circumferential direction. This allows the rotating cam 43 to be displaced parallel to the direction of the motor axis J, particularly toward the lock side (rearward).

[0063] The fixed cam 44 functions as a cam receiving side with which the first to third cam crests 43c, 43d, and 43e of the rotating cam 43 mesh, and is fixed to the lid 25a of the mechanism case 25. Therefore, the fixed cam 44 is fixed so as not to rotate around the motor axis J and so as not to move in the direction of the motor axis J. The fixed cam 44 has three cam valleys 44a, 44b, and 44c and three cam crests 44d, 44e, and 44f in the circumferential direction. The three cam valleys 44a, 44b, and 44c are unequally spaced around the motor axis J, and the lengths of their circumferential regions are different from one another. The circumferential regions of the first cam valley 44a and the second cam valley 44b are shorter than the third cam valley 44c. The circumferential region of the third cam valley 44c is the longest. The circumferential region of the third cam valley portion 44c is set to a length that can accommodate the third cam crest portion 43e of the rotating cam 43. The circumferential regions of the first cam valley portion 44a and the second cam valley portion 44b are set to approximately the same length.

[0064] The length of the circumferential region of the first cam valley portion 44a and the second cam valley portion 44b is shorter than the length of the circumferential region of the third cam crest portion 43e of the rotating cam 43. For this reason, the third cam crest portion 43e cannot enter the first cam valley portion 44a and the second cam valley portion 44b.

[0065] When the rotating cam 43 rotates in the direction of arrow R relative to the fixed cam 44 and the third cam peak 43e, which has the longest circumferential area of ​​the rotating cam 43, reaches below the third cam valley 44c, which has the longest circumferential area of ​​the fixed cam 44, the rotating cam 43 is displaced (upward) toward the fixed cam 44 by the biasing force of the compression spring 45. This causes the locking member 41 to retract upward from the insertion hole 28 of the wheel 22, and the wheel 22 becomes capable of radial displacement relative to the rotation shaft 21.

[0066] FIG. 7 shows the meshed state of the cam mechanism 42. In this meshed state, the third cam peak 43e of the rotating cam 43 reaches below the third cam valley 44c of the fixed cam 44, and the rotating cam 43 is moved upward by the biasing force of the compression spring 45. Therefore, when the cam mechanism 42 meshes, the locking member 41 retracts from the insertion hole 28, allowing the wheel 22 to move radially (the displacement restriction state is released). This meshed state is realized only in one area in the rotational direction. Therefore, the retraction of the locking member 41 from the insertion hole 28 is limited to a certain angular range of the rotational movement of the wheel 22, as shown below.

[0067] The relative position of the rotating cam 43, which rotates integrally with the wheel 22, in the rotational direction with respect to the fixed cam 44 is set so that the third cam peak 43e is located below the third cam valley 44c when the first engaging portion P1 engages with the engaged portion L of the driver 15. This causes the locking member 41 to retract from the insertion hole 28 at the latest before the first engaging portion P1 interferes with the engaged portion L, thereby allowing radial displacement of the wheel 22. By allowing radial displacement of the wheel 22, interference between the engaging portion P of the wheel 22 and the engaged portion L of the driver 15 is avoided.

[0068] The timing before the first engaging portion P1 interferes with the engaged portion L is the initial stage of engagement of the first engaging portion P1 of the wheel 22 with the engaged portion L of the driver 15, and corresponds to the initial stage of the start of upward movement of the driver 15. In this embodiment, the relative positions of the rotating cam 43 and the fixed cam 44 around the motor axis J are set so that radial displacement of the wheel 22 is permitted, for example, at the stage when the first engaging portion P1 enters the driving passage 2a through the window portion 25b of the mechanism case 25 (just before engaging with the third engaged portion L3).

[0069] FIG. 8 shows the disengaged state of the cam mechanism 42. As shown in FIG. 8, when the third cam crest 43e of the rotating cam 43 is shifted in the rotational direction from or not positioned below the third cam valley 44c of the fixed cam 44, even if the first and second cam crests 43c, 43d are below the second and third cam valleys 44b, 44c, a portion of the third cam crest 43e abuts the third cam crest 44d of the fixed cam 44. This restricts upward displacement of the rotating cam 43, resulting in a disengaged state. In this disengaged state, the rotating cam 43 remains displaced downward (in the direction of arrow D in FIG. 8) against the compression spring 45. This keeps the locking member 41 inserted into the insertion hole 28, restricting radial displacement of the wheel 22 relative to the rotation shaft 21.

[0070] In this way, by rotating the wheel 22 in the direction of arrow R, the rotating cam 43 and the fixed cam 44 mesh with each other in a region where the third cam peak 43e of the rotating cam 43 is located below the third cam valley 44c of the fixed cam 44. This causes the rotating cam 43 to be displaced upward, causing the locking member 41 to retract from the insertion hole 28, and allowing the wheel 22 to be displaced in the radial direction. As described above, the region where the locking member 41 retracts from the insertion hole 28 is set to a partial rotation region of the wheel 22. In this embodiment, the first engaging portion P1 is set to a certain region before and after engaging with the engaged portion L of the driver 15.

[0071] In this embodiment, for example, at the time when the first engaging portion P1 engages with the engaged portion L, or immediately before the second engaging portion P2 engages with the engaged portion L of the driver 15, the locking member 41 enters the insertion hole 28, restricting radial displacement of the wheel 22. At the time when the second engaging portion P2 engages with the engaged portion L, the first engaging portion P1 is already engaged with the engaged portion L. As a result, by slightly moving the driver 15 upward, the relative position of the second engaging portion P2 with respect to the engaged portion L is corrected to a state where smooth engagement is achieved. For this reason, at the time when the second engaging portion P2 engages with the engaged portion L, it is more desirable to restrict radial displacement and achieve a reliable engagement state than to allow the wheel 22 to displace radially.

[0072] As the wheel 22 continues to rotate with its radial displacement restricted, the third engagement portion P3, the fourth engagement portion P4, ... are engaged with the engaged portion L in this order, thereby moving the driver 15 upward. As described above, the radial displacement of the wheel 22 is restricted by the displacement restriction mechanism 40, except for the initial stage of the upward movement of the driver 15 when the first engagement portion P1 is engaged with the engaged portion L. Therefore, the second engagement portion P2, the third engagement portion P3, ... and the final engagement portion P10 are reliably engaged with the engaged portion L in turn. As a result, power for moving the driver 15 upward relative to the driver 15 is reliably transmitted from the wheel 22 to the driver 15 while receiving the gas pressure of the accumulator chamber 14 applied via the driver 15.

[0073] For example, as shown in FIG. 16 , at a stage where the displacement direction of the wheel 22 (the direction of the sliding contact surface between the support flat surface 21 a and the slide surface 28 a) is parallel or approximately parallel to the movement direction of the driver 15 (the up-down direction), almost all of the thrust due to the gas pressure in the accumulator chamber 14 acts as an external force in a direction that displaces the wheel 22. However, at this stage, the lock member 41 is inserted into the insertion hole 28, and the radial displacement of the wheel 22 is restricted. Therefore, once the fourth engagement portion P4 is engaged with the final engagement portion L10, the wheel 22 reliably transmits the power of the drive unit 30 to the driver 15 while receiving the thrust of the accumulator chamber 14. This reliably moves the driver 15 upward.

[0074] The rotation of the wheel 22 sequentially engages the engaging portion P with the engaged portion L, returning the driver 15 to the standby position. At this stage, the electric motor 32 stops and the driver 15 is held in the standby position. This allows the operator to remove the driving tool N jammed in the driving passage 2a, as described above. After that, the driver 15 is moved to the upper end of its travel by restarting the drive unit 30 by pulling the switch lever 3a. When the driver 15 reaches the upper end of its travel, the wheel 22 starts to spin freely, correcting the misalignment of the engaging portion P of the driver 15 with the engaged portion L. After the final engaging portion P10 has been corrected to an engaged state with the final engaged portion L10, the wheel 22 continues to rotate, disengaging the two, causing the driver 15 to move downward and perform the driving operation.

[0075] According to the driving tool 1 described above, the wheel 22 of the lift mechanism 20 is capable of being displaced radially relative to the rotation shaft 21 by the displacement allowance mechanism 27. This prevents interference (an abnormal engagement state) between the first engagement portion P1 and the engaged portion L of the driver 15, and the first engagement portion P1 engages with the underside of the engaged portion L. This allows the driver 15 to be returned quickly and smoothly to the standby position even if a nail jam occurs, for example.

[0076] In the illustrated embodiment, interference of the first engagement portion P1 is avoided by displacing the entire wheel 22 in the radial direction relative to the rotation shaft 21. This simplifies the configuration compared to a configuration in which only a portion of the wheel is displaced.

[0077] The wheel 22 is displaced radially only in the initial stage of the upward movement of the driver 15 (the stage at which the first engagement portion P1 engages with or interferes with the engaged portion L). At the stages at which the second to final engagement portions (P2 to P10) engage with the engaged portion L, the displacement of the wheel 22 in the radial direction is restricted by the displacement restriction mechanism 40. As a result, the upward movement of the driver 15 is reliably performed by the lift mechanism 20 while receiving the gas pressure from the pressure accumulator chamber 14.

[0078] In the illustrated embodiment, at the stage where the displacement direction of the wheel 22 (the surface direction of the slide surface 28a) becomes parallel to the movement direction of the driver 15, the radial displacement of the wheel 22 is already restricted by the displacement restriction mechanism 40. At the stage where the direction of the force received from the driver 15 (the movement direction of the driver 15) coincides with the displacement direction of the wheel 22, the engaging portion P receives a large external force (thrust of gas pressure) in the wheel displacement direction from the driver 15. Therefore, at this stage at the latest, the radial displacement of the wheel is restricted by the displacement restriction mechanism, and the engagement state of the lift mechanism 20 with the driver 15 is maintained in a good state, thereby avoiding malfunction.

[0079] In the illustrated embodiment, the locking member 41 is inserted between the insertion hole 28 of the wheel 22 and the rotation shaft 21 that supports the wheel 22, thereby restricting radial displacement of the wheel 22 relative to the rotation shaft 21. When the locking member 41 is retracted from the insertion hole 28, radial displacement of the wheel 22 relative to the rotation shaft 21 is permitted. By a simple configuration of moving the locking member 41 forward and backward relative to the insertion hole 28, the state in which radial displacement of the wheel 22 is permitted and the state in which it is restricted can be switched.

[0080] In the illustrated embodiment, the locking member 41 is displaced in the axial direction of the rotating shaft 21 (direction of the motor axis J) to advance and retreat into the insertion hole 28. The locking member 41 advances and retreats into and from the insertion hole 28 with a simple and compact configuration.

[0081] In the illustrated embodiment, the locking member 41 is positioned on the inner peripheral side of the engaging portion P, thereby making the displacement restriction mechanism 40 compact.

[0082] In the illustrated embodiment, the cam mechanism 42 causes the locking member 41 to advance into and retreat from the insertion hole 28 in conjunction with the rotation of the wheel 22. The cam mechanism 42 enables the locking member 41 to operate accurately and reliably.

[0083] In the illustrated embodiment, a pair of slide surfaces 28a of the insertion hole 28 and a pair of support planes 21a of the rotating shaft 21 are brought into sliding contact with each other, so that the wheel 22 is integrated with the rotating shaft 21 in terms of rotation, and the wheel 22 is supported so as to be displaceable radially relative to the rotating shaft 21.

[0084] In the illustrated embodiment, the wheel 22 is biased in a direction approaching the driver 15 by a compression spring 29 installed in the insertion hole 28. This causes the wheel 22 to return to a position where it is coaxial with the rotary shaft 21 (a normal engagement position with the driver 15). By installing the compression spring 29 in the insertion hole 28, the displacement allowance mechanism 27 can be made compact.

[0085] In the illustrated embodiment, the displacement restriction mechanism 40 has a compression spring 45 that biases the locking member 41 in a direction to retract from the insertion hole 28. This ensures that the locking member 41 is reliably retracted from the insertion hole 28 with a simple configuration.

[0086] In the illustrated embodiment, the cam mechanism 42 has a plurality of cam portions C1, C2, and C3 that are unequally spaced about the axis of the rotary shaft 21 (about the motor axis J). This allows the rotary cam 43 and the fixed cam 44 to mesh with each other at only one location about the axis of the rotary shaft 21. This fixes the advancement and retreat of the lock member 41 relative to the insertion hole 28 at one location about the axis of the rotary shaft 21. This reliably allows and restricts radial displacement of the wheel 22 at one fixed location about the axis of the rotary shaft 21. This maintains a good engagement state of the lift mechanism 20 with the driver 15.

[0087] Various modifications can be made to the above-described embodiment. For example, in the lift mechanism 20, the wheel 22 has ten engaging portions P and the driver 15 has ten engaged portions L, but the number of engaging portions P and engaged portions L is not limited to ten. The number of engaging portions P and engaged portions L is appropriately set depending on factors such as the stroke of the driver or the size of the main body 10.

[0088] Although the compression spring 29 is exemplified as an urging member that urges the wheel 22 toward the driver 15, it may be replaced with other urging members such as a leaf spring or urethane rubber. The urging member that urges the wheel 22 toward the driver 15 may be configured to be disposed outside the insertion hole 28.

[0089] The three cam peaks 43c, 43d, and 43e of the rotating cam 43 are circumferentially unequally spaced by varying the lengths of their circumferential regions and arranging their starting points at different intervals in the circumferential direction. However, they may be circumferentially unequally spaced by varying the lengths of their circumferential regions with the same starting points, or by circumferentially unequally spaced by varying the lengths of their circumferential regions with the same length. In either case, the rotating cam and the fixed cam may be meshed only in one region in the rotational direction. Furthermore, the three lift portions 43f, 43g, and 43h are circumferentially unequally spaced by their circumferential regions with the same length (the same inclination angle allows for uniform lift). However, if the starting points of the cam peaks are spaced at equal intervals but have different circumferential lengths, they may be circumferentially unequally spaced by their circumferential regions with the same length.

[0090] The number of cam portions of the cam mechanism is not limited to three around the axis as illustrated, but may be two, or four or more.

[0091] As illustrated above, it is desirable to set the displacement direction of the wheel 22 so that the first engagement portion P1 is approximately parallel to the direction of the external force F that is received from the engaged portion L of the driver 15. This allows the wheel 22 to be more smoothly displaced in the direction away from the engaged portion L when the first engagement portion P1 interferes with the engaged portion L. However, it is permissible to appropriately shift the displacement direction of the wheel 22 around the motor axis J relative to the direction of the external force F.

[0092] 17 to 26 show an example of a lift mechanism 50 according to the second embodiment. The lift mechanism 50 according to the second embodiment includes a displacement allowance mechanism 60 that is the same as that of the first embodiment, and a displacement restriction mechanism 70 that is different from that of the first embodiment. Members and configurations that are the same as those of the first embodiment and do not require change in the second embodiment will be denoted by the same reference numerals and will not be described again.

[0093] The lift mechanism 50 according to the second embodiment has a rotary shaft 51 rotated by an electric motor 32 and a wheel 52 supported by the rotary shaft 51. When the electric motor 32 is started, the wheel 52 of the lift mechanism 50 rotates integrally. The wheel 52 has two flange portions 52a that are parallel to each other and spaced apart by a fixed distance. A plurality of engagement portions P are provided parallel to each other and supported at both ends across the periphery of the two flange portions 52a. In the second embodiment, ten engagement portions P (P1 to P10) are also illustrated. Each engagement portion P uses a cylindrical shaft member (pin).

[0094] As in the first embodiment, ten engaged portions L (L1 to L10) are arranged at regular intervals in the longitudinal direction (vertical direction) on the right side of the driver 15. With each engaging portion P of the wheel 52 engaged with the engaged portion L of the driver 15, the wheel 52 rotates, causing the driver 15 and piston 13 to return upward. When the electric motor 32 is activated, the wheel 52 rotates counterclockwise as indicated by the arrow R in the figure.

[0095] The lift mechanism 50 according to the second embodiment has a displacement allowance mechanism 60 for allowing radial displacement of the wheel 52. The displacement allowance mechanism 60 has an insertion hole 61 provided in the wheel 52. A pair of sliding surfaces 61a that are parallel to each other and extend radially are provided on the inner wall surface of the insertion hole 61. The insertion hole 61 is formed in the shape of an elongated hole that is long in the radial direction so as to allow radial displacement of the wheel 52 relative to the rotation shaft 51.

[0096] The rotary shaft 51 is inserted through the insertion hole 61. A slide surface 61a of the insertion hole 61 is in sliding contact with a support flat surface 51a of the rotary shaft 51. As a result, the wheel 52 is supported so as to be rotatable integrally with the rotary shaft 51 and so as to be displaceable within a certain range in the radial direction. Displacing the wheel 52 in the radial direction with respect to the rotary shaft 51 prevents interference between the engaging portion P and the engaged portion L of the driver 15. A compression spring 62 is interposed between the inner wall surface of the insertion hole 61 and the rotary shaft 51. The biasing force of the compression spring 62 biases the wheel 52 toward the engaging side, which brings the engaging portion P closer to the engaged portion L of the driver 15. Therefore, radial displacement of the wheel 52 toward the non-engagement side is performed against the biasing force of the compression spring 62. As shown in Figures 20 to 22, when the wheel 52 is displaced toward the non-engagement side against the compression spring 62, a gap 61b corresponding to the displacement distance is generated between the outer surface of the rotating shaft 51 on the side opposite the compression spring 62 and the inner surface of the insertion hole 61.

[0097] The lift mechanism 50 of the second embodiment includes a displacement restriction mechanism 70 that restricts radial displacement of the wheel 52. The displacement restriction mechanism 70 includes restriction disks 71 and 72 and restriction members 73 and 74. As shown in FIGS. 17 and 18 , the restriction disks 71 and 72 are disposed above and below the wheel 52. The two restriction disks 71 and 72 have disk shapes of roughly the same diameter and are disposed coaxially and parallel to each other. The two restriction disks 71 and 72 are fixed to the mechanism case 25. Therefore, the two restriction disks 71 and 72 do not rotate even when the electric motor 32 is started. Insertion holes 71a and 72a are formed in the centers of the two restriction disks 71 and 72. The rotation shaft 51 is inserted through the two insertion holes 71a and 72a so as to be rotatable relative to each other. An arc-shaped notch 72d is formed in a certain range on the outer periphery of the lower restriction disk 72. This notch 72d facilitates the work of assembling the magazine 6 to the driving nose portion 2.

[0098] Restriction wall portions 71b, 72b are provided on the lower surface of the upper restricting disk 71 and the upper surface of the lower restricting disk 72, respectively. The restricting wall portions 71b, 72b are provided symmetrically above and below. In the second embodiment, the outer peripheral wall surfaces of grooves provided in the restricting disks 71, 72 serve as the restricting wall portions 71b, 72b. The restricting wall portions 71b, 72b are each provided with a deregulation portion 71c, 72c at one location in the circumferential direction. In the second embodiment, a recess recessed toward the outer peripheral side serves as the deregulation portion 71c, 72c.

[0099] The upper deregulation portion 71c and the lower deregulation portion 72c are arranged facing each other vertically at the same position around the motor axis J. The two deregulation portions 71c, 72c are arranged on the opposite side of the rotary shaft 51 from the driver 15. The two deregulation portions 71c, 72c are provided within a certain angular range (for example, approximately 40°) around the motor axis J. In the second embodiment, they are provided within an angular range equivalent to the distance between two adjacent engagement portions P (sixth and seventh engagement portions P6, P7 in FIGS. 19 and 20). The angular range of the deregulation portions 71c, 72c may be expanded to approximately 60°.

[0100] As shown in Figure 21, the upper and lower regulating members 73, 74 are provided using the engagement portions P of the wheel 52. In the second embodiment, the regulating members 73, 74 are provided using the seventh engagement portion P7 of the ten engagement portions P. Both upper and lower ends of the seventh engagement portion P7 protrude upward and downward from the flange portion 52a. A roller body is supported on the protruding portion of the seventh engagement portion P7 so as to be rotatable about its axis. The upper and lower roller bodies serve as the regulating members 73, 74, respectively.

[0101] The upper and lower regulating members 73 and 74 move along the regulating wall portions 71b and 72b in accordance with the rotation of the wheel 52. When the regulating members 73 and 74 move along the regulating wall portions 71b and 72b, radial displacement of the wheel 52 relative to the rotation shaft 51 is restricted. Therefore, the wheel 52 rotates in the direction of arrow R around the motor axis J.

[0102] As shown in Figures 19 and 20, rotation of the wheel 52 in the direction of arrow R causes the first engagement portion P1 to enter the driving passage 2a and engage with the engaged portion L of the driver 15. At this stage, as shown in Figures 22 and 23, the restricting members 73 and 74 supported by the seventh engagement portion P7 on the opposite side of the first engagement portion P1 disengage from the restricting walls 71b and 72b, respectively, and enter the unrestricted portions 71c and 72c. When the restricting members 73 and 74 reach the unrestricted portions 71c and 72c, they can be displaced outward (they can enter the unrestricted portions 71c and 72c). This allows the wheel 52 to enter a unrestricted state in which it can be displaced away from the driver 15 against the compression spring 62.

[0103] Therefore, as in the first embodiment, when a large external force F is applied to the wheel 52 via the first engaging portion P1 due to misalignment caused by a nail jamming or the like, the entire wheel 52 is displaced radially against the compression spring 62 as shown in Figures 20 to 22. Therefore, a gap 61b is generated between the rotating shaft 51 and the insertion hole 61. This prevents the first engaging portion P1 from interfering with the third engaged portion L3 (locked engagement state).

[0104] As the wheel 52 rotates in the direction of arrow R while displacing away from the driver 15, the first engaging portion P1 passes beside the third engaged portion L3. At this stage, the external force F in the sliding direction received from the third engaged portion L3 decreases. Therefore, as shown in FIG. 24, the wheel 52 is returned in a direction approaching the driver 15 by the biasing force of the compression spring 62. As the wheel 52 rotates while being returned, the first engaging portion P1 abuts against the lower surface of the second engaged portion L2. At this stage, the restricting members 73 and 74 disengage from the restriction release portions 71c and 72c and are again in a state of moving along the restricting wall portions 71b and 72b. Therefore, the radial displacement of the wheel 52 is switched to a state in which it is restricted.

[0105] As the wheel 52 continues to rotate with the first engaging portion P1 normally engaged with the underside of the engaged portion L, the driver 15 is displaced upward from the stopped position. As shown in Figures 25 and 26, at this stage, the upper and lower regulating members 73, 74 continue to move along the regulating walls 71b, 72b, thereby maintaining a state in which radial displacement of the wheel 52 relative to the rotation shaft 51 is regulated. This returns the driver 15 to the upper standby position.

[0106] In the second embodiment illustrated above, the radial displacement of the wheel 52 by the displacement allowing mechanism 60 is also permitted within a certain range before and after the first engaging portion P1 engages with the engaged portion L. At the stage where the second to final engaging portions (P2 to P10) engage with the engaged portion L of the driver 15, the radial displacement of the wheel 52 is restricted by the displacement restricting mechanism 70.

[0107] The timing at which the displacement allowance mechanism 60 allows the wheel 52 to be displaced in the radial direction can be changed as needed. Therefore, the positions of the restriction members 73, 74 can be changed to positions displaced forward or backward in the rotational direction from the seventh engagement portion P7 shown as an example. In addition, the positions of the restriction release portions 71c, 72c around the motor axis J can also be changed to positions displaced forward or backward in the rotational direction. Furthermore, as described above, the angular range of the restriction release portions 71c, 72c may be expanded or contracted from the range of approximately 40° shown as an example.

[0108] As in the first embodiment, the timing for returning the wheel 52 from a state in which radial displacement is permitted to a state in which radial displacement is restricted can be set to the point in time when the first engaging portion P1 is normally engaged with the engaged portion L of the driver 15, or can be changed as appropriate. For example, the restricting members 73, 74 may be configured to disengage from the restriction release portions 71c, 72c and switch to the restricted state at the stage when the second engaging portion P2 is engaged with the engaged portion L.

[0109] According to the second embodiment, the cam mechanism 42 of the first embodiment can be omitted, which makes it possible to make the lift mechanism 50 more compact in the direction of the motor axis J and to simplify the configuration.

[0110] Further modifications can be made to the second embodiment. For example, although the configuration in which the two restricting members 73, 74 are provided on both the upper and lower sides of the wheel 52 has been exemplified, one of them may be omitted.

[0111] Although the configuration in which the regulating members 73 and 74 are arranged using one engagement portion P (seventh engagement portion P7) has been exemplified, a configuration in which the regulating members are arranged separately from the engagement portion P may also be used.

[0112] In the second embodiment, the outer wall surfaces of the groove portions are used as the regulating wall portions 71b, 72b, but the regulating wall portions may also be formed by providing annular protruding wall portions symmetrically above and below on the opposing surfaces of the upper and lower regulating discs 71, 72.

[0113] The driving tool 1 of the first and second embodiments is an example of a driving tool according to one aspect of the present disclosure. The piston 13 of the first and second embodiments is an example of a piston according to one aspect of the present disclosure. The driver 15 of the first and second embodiments is an example of a driver according to one aspect of the present disclosure. The engaged portions L (L1 to L10) of the first and second embodiments are an example of a plurality of engaged portions according to one aspect of the present disclosure.

[0114] The lift mechanism 20 of the first embodiment and the lift mechanism 50 of the second embodiment are examples of lift mechanisms in one aspect of the present disclosure. The rotating shaft 21 of the first embodiment and the rotating shaft 51 of the second embodiment are examples of rotating shafts in one aspect of the present disclosure. The wheel 22 of the first embodiment and the wheel 52 of the second embodiment are examples of wheels in one aspect of the present disclosure. The engaging portions P (P1 to P10) of the first and second embodiments are examples of engaging portions in one aspect of the present disclosure.

[0115] The displacement allowance mechanism 27 of the first embodiment and the displacement allowance mechanism 60 of the second embodiment are examples of displacement allowance mechanisms in one aspect of the present disclosure. The displacement restriction mechanism 40 of the first embodiment and the displacement restriction mechanism 70 of the second embodiment are examples of displacement restriction mechanisms in one aspect of the present disclosure. The first engagement portion P1 of the first and second embodiments is an example of a first engagement portion in one aspect of the present disclosure. The second engagement portion P2 of the first and second embodiments is an example of a second engagement portion in one aspect of the present disclosure. [Explanation of symbols]

[0116] 1...Driving tool N...Driver 2...Driving nose part 2a... firing passage, 2b... ejection port 3...Grip section 3a...Switch lever 4. Battery mounting section 5. Battery pack 6...Magazine 10...Main body 11...Main body housing 12...Cylinder 13...Piston 14...Pressure chamber 15...Driver L…Engaged part L1...first engaged part, L2...second engaged part, L3...third engaged part, L4...fourth engaged part L5...5th engaged part, L6...6th engaged part, L7...7th engaged part, L8...8th engaged part L9...Ninth engaged part, L10...Final engaged part 16...Lower moving end damper 20...Lift mechanism (first embodiment) 21...rotating shaft (first embodiment) 21a...Support plane, 21b...Support plane 22...Wheel (first embodiment) 22a...Flange part P…Engagement part P1...first engagement part, P2...second engagement part, P3...third engagement part, P4...fourth engagement part, P5...fifth engagement part P6...6th engaging part, P7...7th engaging part, P8...8th engaging part, P9...9th engaging part P10: Final engagement part F: External force in the sliding direction applied to the engagement portion P of the wheels 22 and 52 23, 24...Bearings 25...Mechanism case 25a...lid portion, 25b...window portion 26...Relief section 27...Displacement allowance mechanism (first embodiment) 28...Through hole 28a...Slide surface 29...Compression spring 30...Drive unit 31...Drive unit case 32...Electric motor 32a...output shaft, 32b...motor housing, 32c, 32d...bearings J: Motor axis 33...Reduction gear train 40...Displacement restriction mechanism (first embodiment) 41...locking member 42...Cam mechanism 43...Rotating cam C1, C2, C3...Cam section 43a...support hole, 43b...receiving surface 43c...first cam top, 43d...second cam top, 43e...third cam top 43f, 43g, 43h...Lift section 44...Fixed cam 44a...first cam valley portion, 44b...second cam valley portion, 44c...third cam valley portion 44d, 44e, 44f...Cam top 45...Compression spring 50...Lift mechanism (second embodiment) 51...rotating shaft (second embodiment) 51a...Support plane 52...Wheel (Second embodiment) 52a...Flange part 60...Displacement allowance mechanism (second embodiment) 61...Through hole 61a...slide surface, 61b...gap 62...Compression spring 70...Displacement restriction mechanism (second embodiment) 71...Regulating disc (upper) 71a...insertion hole, 71b...restriction wall portion, 71c...restriction release portion 72...Regulating disc (lower) 72a...insertion hole, 72b...restriction wall portion, 72c...restriction release portion, 72d...missing portion 73...Regulating member (upper side) 74...Regulating member (lower side)

Claims

1. A driving tool, A piston that moves in the driving direction by gas pressure, a driver that moves integrally with the piston and strikes the driving tool; a lift mechanism that moves the driver in a direction opposite to the driving direction; The driver includes a plurality of engagement portions along a longitudinal direction, The lift mechanism includes: A rotation axis; a wheel that rotates together with the rotation axis around the rotation axis; a plurality of engaging portions arranged along a certain range in the circumferential direction of the wheel, and rotating together with the rotation shaft to sequentially engage with the engaged portion of the driver; a displacement allowing mechanism in which the rotation shaft is inserted into an insertion hole formed in the wheel so as to be elongated in the radial direction and be capable of relative displacement in the radial direction, thereby allowing radial displacement of the wheel relative to the rotation shaft; a displacement restriction mechanism that has a cam mechanism that moves a locking member forward and backward relative to the insertion hole in accordance with rotation of the wheel, and that restricts displacement of the wheel in the radial direction relative to the rotation axis by inserting the locking member into the insertion hole through operation of the cam mechanism, a relief portion that allows movement of the driver in the driving direction in a remaining circumferential range excluding the certain circumferential range is set on the wheel; the plurality of engaging portions include a first engaging portion that is located immediately behind the relief portion in the rotational direction of the wheel and that first engages with the engaged portion when the lift mechanism moves the driver in the counter-driving direction, At least at the stage when the first engaging portion engages with the engaged portion and the driver begins to move in the counter-driving direction, the cam mechanism operates to cause the locking member to withdraw from the insertion hole, thereby releasing the displacement restriction state of the wheel by the displacement restriction mechanism.

2. The driving tool according to claim 1, the plurality of engaging portions include a second engaging portion that engages with the engaged portion next to the first engaging portion, A driving tool in which, at least at the stage when the second engaging portion engages with the engaged portion, the locking member enters the insertion hole due to the operation of the cam mechanism, thereby restricting radial displacement of the wheel relative to the rotation axis.

3. The driving tool according to claim 1 or 2, When the rotation of the wheel causes the longitudinal direction of the insertion hole to become at least parallel to the direction of movement of the driver, and the displacement direction of the wheel relative to the rotation axis coincides with the direction of action of the thrust of the gas pressure, the locking member enters the insertion hole due to the operation of the cam mechanism, thereby regulating the radial displacement of the wheel relative to the rotation axis.

4. The driving tool according to any one of claims 1 to 3, The locking member is displaced in the axial direction of the rotary shaft to advance into and retract from the insertion hole.

5. The driving tool according to any one of claims 1 to 4, A driving tool in which the locking member is located on the inner peripheral side of the engaging portion.

6. The driving tool according to any one of claims 1 to 5, a hole wall surface that constitutes the insertion hole has a pair of slide surfaces that are parallel to each other and extend in the radial direction, The driving tool includes a pair of support planes, each of which faces the pair of slide surfaces and extends in the radial direction.

7. The driving tool according to any one of claims 1 to 6, A driving tool having a biasing member mounted in the insertion hole, the biasing member biasing the wheel in a direction in which the engaging portion of the wheel engages with the engaged portion of the driver.

8. The driving tool according to any one of claims 1 to 7, The displacement restriction mechanism is a driving tool having a biasing member that biases the locking member in a direction to retract from the insertion hole.

9. The driving tool according to any one of claims 1 to 8, The cam mechanism has a plurality of cam portions that are unequally spaced around the axis of the rotating shaft, and all of the plurality of cam portions engage with the cam receiving side at one point around the axis of the rotating shaft, thereby fixing the movement of the locking member back and forth relative to the insertion hole to one point around the axis of the rotating shaft.

10. A driving tool, A piston that moves in the driving direction by gas pressure, a driver that moves integrally with the piston and strikes the driving tool; a lift mechanism that moves the driver in a direction opposite to the driving direction; The driver includes a plurality of engagement portions along a longitudinal direction, The lift mechanism includes: A rotation axis; a wheel that rotates together with the rotation shaft around the rotation shaft; a plurality of engaging portions arranged along a certain range in the circumferential direction of the wheel, and rotating together with the rotation shaft to sequentially engage with the engaged portion of the driver; a displacement allowing mechanism in which the rotation shaft is inserted into an insertion hole formed in the wheel so as to be elongated in the radial direction and be capable of relative displacement in the radial direction, thereby allowing radial displacement of the wheel relative to the rotation shaft; a displacement restriction mechanism that restricts displacement of the wheel in the radial direction, the displacement restriction mechanism includes a restriction member provided on the wheel, a restriction wall portion provided along the periphery of the wheel and contacting the restriction member to restrict displacement of the wheel in the radial direction, and a restriction release portion that is released from contact with the restriction wall portion to allow displacement of the wheel in the radial direction, a relief portion that allows movement of the driver in the driving direction in a remaining circumferential range excluding the certain circumferential range is set on the wheel; the plurality of engaging portions include a first engaging portion that is located immediately behind the relief portion in the rotational direction of the wheel and that first engages with the engaged portion when the lift mechanism moves the driver in the counter-driving direction, A driving tool in which, at least at the stage when the first engaging portion engages with the engaged portion and the driver begins to move in the counter-driving direction, the abutment state of the regulating member against the regulating wall portion is released and the displacement restriction state of the wheel by the regulating member is released.

11. The driving tool according to claim 10, A driving tool in which the regulating member protrudes from both sides in the axial direction of the wheel.

12. The driving tool according to claim 10 or 11, A driving tool in which both ends of the engagement portion protrude on both sides in the axial direction of the wheel, and the regulating member is provided using the protruding portions of the engagement portion.

13. The driving tool according to any one of claims 10 to 12, The driving tool, wherein the regulating member is disposed on the opposite side of the rotation shaft from the first engaging portion.

14. The driving tool according to any one of claims 10 to 13, The driving tool has a roller body that is rotatable around an axis provided on the regulating member.

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