Driving tool

Abstract

To provide a lift mechanism that is able to continue a good operation between when a normal operation performed and when a driver stops at an incorrect position.SOLUTION: There is a need for a lift mechanism which can continue a good operation when normal operation and when a driver stops at an incorrect position. A driving tool 1 has: a piston 13 that moves in a driving direction by means of a gas pressure; a driver 15 having a plurality of to-be-engaged portions 16 extending from the piston 13 and aligned in the driving direction; and a lift mechanism 20 that moves the driver 15 in a counter-driving direction. The lift mechanism 20 has: a rotation shaft 21; a wheel 22 that rotates together with the rotation shaft 21 around the rotation shaft 21; a plurality of engaging portions 25 arranged along an outer periphery of a wheel 22 and that are engaged with the to-be-engaged portions 16; and a support member 21a supporting the wheel 22 movably in a radial direction between an initial position and an eccentric position with respect to the rotation shaft 21. During movement of the driver 15 in the counter-driving direction, the wheel 22 is displaced into a first state in which the wheel is engaged with the driver 15 at the initial position and can be retracted to the eccentric position and into a second state in which the wheel is engaged with the driver 15 at the eccentric position.SELECTED DRAWING: Figure 8

Description

Technical Field

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

Background Art

[0002] Patent Documents 1 and 2 disclose a gas spring type driving tool that utilizes the thrust of compressed gas as a striking force. The gas spring type driving tool has a piston that moves up and down in a cylinder and a driver that is integrally coupled to the piston. The piston and the driver are moved downward in the driving direction by the gas pressure in the accumulator chamber. The driver strikes and ejects the lower driving tool. After ejecting the driving tool, the piston and the driver are returned in the reverse driving direction by a lift mechanism.

[0003] The driver has a plurality of engaged portions (rack teeth) that extend in the vertical direction and are formed side by side in the vertical direction. The lift mechanism has a wheel having a plurality of engaging portions that engage with the plurality of engaged portions. The plurality of engaging portions are arranged along the outer circumference of the wheel. The wheel is rotated by a driving source such as an electric motor. By rotating the wheel after the driving operation, the engaging portions are sequentially engaged with the engaged portions of the driver. As a result, the driver and the piston move upward in the reverse driving direction. When the piston moves upward in the reverse driving direction, the gas pressure in the accumulator chamber is increased. When the driver is moved upward to the upper end position, the engagement state of the engaging portion of the lift mechanism with the engaged portion of the driver is released. As a result, the driving operation of the driver is performed again.

[0004] When the engaging portion of the lift mechanism moves the driver upward against the gas pressure in the accumulator chamber, the engaging portion receives a large load from the engaged portion of the driver. Therefore, it is desirable that the engaging portion and the engaged portion are normally engaged and the driver is moved upward while the engaging portion is reliably receiving the load.

[0005] However, there are cases where the engaging portion and the engaged portion do not engage properly and interfere with each other, causing the return operation of the driver to stop. For example, when driving a driving tool into hard wood or accidentally driving the driving tool into an iron plate or the like, the driving tool may be struck by the driver in the driving passage and deformed, causing jamming. Alternatively, the driving tool may not be driven to the regular depth, resulting in an under-driven state. In these cases, the driver stops at a position above the lower end position. The wheel of the lift mechanism rotates in the same manner as during normal operation even when the driver stops at an irregular position. Therefore, when the upward movement of the driver starts, the engaging portion does not engage with the engaged portion that engages properly, and the bottoms of the engaging portion and the engaged portion interfere with each other.

[0006] There has been no technique for taking measures to quickly return the driver to a state where it operates normally when the driver stops at an irregular position due to interference between the bottom of the engaging portion and the engaged portion.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] Therefore, there is a need for a lift mechanism that can continue to operate well both during normal operation and when the driver stops at an irregular position.

Means for Solving the Problems

[0009] According to one feature of the present disclosure, the driving tool has a piston that moves in the driving direction by gas pressure. The driving tool has a driver that extends from the piston in the driving direction and includes a plurality of engaged portions formed side by side in the driving direction. The driving tool has a lift mechanism that moves the driver in the reverse driving direction. The lift mechanism has a rotation axis and a wheel that rotates together with the rotation axis about the rotation axis. The lift mechanism has a plurality of engagement portions that are arranged along the outer periphery of the wheel and engage with the engaged portions of the driver. The lift mechanism has a support member that is provided on the rotation axis and supports the wheel so as to be radially movable between an initial position and an eccentric position with respect to the rotation axis. When the driver is moved in the reverse driving direction, the wheel is displaced between a first state in which the wheel engages with the driver at the initial position and can retract to the eccentric position, and a second state in which the wheel engages with the driver at the eccentric position.

[0010] Therefore, when the return operation of the driver operates normally, the wheel is positioned at the initial position or the eccentric position according to its rotation angle. Regardless of whether the wheel is positioned at the initial position or the eccentric position, the engagement portion of the lift mechanism engages with the engaged portion of the driver. Therefore, the return operation of moving the driver upward can be continued favorably. For example, when a nail jam or the like occurs during the driving operation and the driver stops at an abnormal position, the engagement portion may not engage with the normal engaged portion, and the engagement portion and the engaged portion may interfere with each other. In this case, the wheel can retract from the initial position to the eccentric position. Therefore, the interference between the engagement portion and the engaged portion can be eliminated. After the interference between the engagement portion and the engaged portion is eliminated, the wheel moves to the initial position or the eccentric position, and the engagement portion engages with the engaged portion. Therefore, the return operation of moving the driver upward can be continued favorably.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0012] According to another feature of the present disclosure, the driving tool has a biasing member that biases the wheel from an eccentric position to an initial position. When the engaging portion does not engage properly with the engaged portion and there is interference, the wheel can be moved from the initial position to the eccentric position to eliminate the interference between the engaging portion and the engaged portion, and then the wheel can be quickly returned to the initial position. Therefore, the engaging portion and the engaged portion can be quickly engaged. As a result, the return operation of the driver can be quickly restored.

[0013] According to another feature of the present disclosure, the support member supports the wheel so as to be linearly reciprocable with respect to the rotation axis. Therefore, the wheel can move in a direction away from the driver only within a predetermined range of rotation angles. Therefore, within the range where the wheel is at a predetermined rotation angle, the interference between the engaging portion and the engaged portion can be eliminated. Outside the range of the predetermined rotation angle, the wheel cannot move away from the driver. Therefore, it is possible to suppress the engaging portion from retreating from the engaged portion. As a result, the return operation of the driver can be continued well.

[0014] According to another feature of the present disclosure, the support member has a pair of support planes that extend in the radial direction and are parallel to each other. The wheel has a mounting hole that is inserted with the support member and has a pair of slide surfaces that face each of the pair of support planes and extend in the radial direction. Therefore, using the support structure of the wheel supported by the rotation axis, the wheel can be moved between the initial position and the eccentric position. Therefore, a moving structure for supporting the wheel so as to be movable in the radial direction can be formed compactly.

[0015] According to another feature of the present disclosure, one of the plurality of engaging portions is a first engaging portion that first engages with the engaged portion when the driver is moved in the counter-driving direction. The first engaging portion is located on a reference circle at a reference distance from the axis of the rotation axis when the wheel is in the initial position. Therefore, the arrangement of each engaging portion that enables the return operation of the driver to be continued well can be easily set based on the reference circle.

[0016] According to another feature of the present disclosure, the plurality of engaging portions include at least one outer-position engaging portion located radially outward of the reference circle within a range of 0° to 90° in the rotational direction of the wheel starting from the first engaging portion. The plurality of engaging portions include at least one inner-position engaging portion located radially inward of the reference circle within a range of 90° to 180° in the rotational direction of the wheel starting from the first engaging portion.

[0017] Therefore, when the outer-position engaging portion engages with the engaged portion, the wheel is pushed by the engaged portion and moves from the initial position to the eccentric position. The wheel moves from the initial position to the eccentric position within a range of the rotation angle from 0° to 90°, with the rotation angle of 0° when the first engaging portion starts to engage with the engaged portion. When the rotation angle is within the range of 90° to 180° and the wheel is in the eccentric position, the engaged portion enters radially inward of the reference circle. Therefore, by providing the inner-position engaging portion arranged radially inward of the reference circle, the inner-position engaging portion and the engaged portion can be engaged without interfering with each other. Thus, when the wheel moves from the initial position to the eccentric position and when the wheel is in the eccentric position, the return operation of the driver can be continued well.

[0018] According to another feature of the present disclosure, the plurality of engaging portions are located on or radially outward of the reference circle within a range of 0° to 90° in the rotational direction of the wheel starting from the first engaging portion. The plurality of engaging portions are located on or radially inward of the reference circle within a range of 90° to 180° in the rotational direction of the wheel starting from the first engaging portion. Therefore, with the rotation angle of 0° when the first engaging portion starts to engage with the engaged portion, the wheel can be continuously moved from the initial position to the eccentric position within a range of the rotation angle from 0° to 90°. When the rotation angle is within the range of 90° to 180° and the wheel is in the eccentric position, the plurality of engaging portions and the plurality of engaged portions can be engaged without interfering with each other.

[0019] According to another feature of the present disclosure, a plurality of engaging portions are located on a reference circle within a range of 180° to 360° in the rotational direction of the wheel starting from the first engaging portion. Therefore, with the rotational angle when the first engaging portion starts engaging with the engaged portion being set as 0°, the wheel is located at the initial position within the range of 180° to 360° of the rotational angle and does not move to the eccentric position. Thus, by arranging the plurality of engaging portions on the reference circle, it is possible to provide the plurality of engaging portions so as not to retract from and not interfere with the engaged portion.

[0020] According to another feature of the present disclosure, two of the plurality of adjacent engaging portions on the radially outer side of the reference circle have a first angle with respect to the center of the rotation axis. Two of the plurality of adjacent engaging portions on the radially inner side of the reference circle have a second angle larger than the first angle with respect to the center of the rotation axis. Therefore, it is possible to make the amount of movement in the counterpunching direction substantially constant while each engaging portion is engaged with the engaged portion. Thus, for example, the engaging portion can be accurately engaged with a plurality of engaged portions arranged at equal intervals in the driving direction. As a result, the driver can be smoothly moved upward.

[0021] According to another feature of the present disclosure, the wheel has a small-diameter outer peripheral edge located on the inner peripheral side of the outermost peripheral end of the outer-position engaging portion and a large-diameter outer peripheral edge located on the outer peripheral side of the small-diameter outer peripheral edge in a region corresponding to the outer-position engaging portion. Therefore, the outer peripheral edge of the wheel can be formed compactly. The wheel moves radially between the initial position and the eccentric position with respect to the rotation axis within the housing portion of the lift mechanism. By forming the outer peripheral edge of the wheel compactly, the housing portion of the lift mechanism can be formed compactly.

[0022] Next, one embodiment of the present disclosure will be described with reference to FIGS. 1 to 13. As an example of the driving tool 1, a gas spring type driving tool that uses the gas pressure in the accumulator chamber above the cylinder as the thrust for driving the driving tool N is shown. In the following description, the driving direction of the driving tool N is downward, and the reverse driving direction is upward. The user of the driving tool 1 is generally located on the left side of the driving tool 1 in FIG. 1. The front side of the user is the rear direction (user side), and the back side opposite to the front side is the front direction. The left and right directions are based on the user.

[0023] As shown in FIGS. 1 and 3, the driving tool 1 has a tool body 10. The tool body 10 has a configuration in which a cylinder 12 is housed in a generally cylindrical body housing 11. A piston 13 is housed in the cylinder 12 so as to be reciprocable vertically. The upper part of the cylinder 12 above the piston 13 communicates with an accumulator chamber 14. Compressed gas such as air is enclosed in the accumulator chamber 14. The gas pressure in the accumulator chamber 14 acts as a thrust for moving the piston 13 downward on the upper surface of the piston 13.

[0024] As shown in FIG. 3, the lower part of the cylinder 12 communicates with a driving passage 2a of a driving nose portion 2 provided at the lower part of the tool body 10. The driving nose portion 2 is coupled to a magazine 8 loaded with a large number of driving tools N (see FIG. 1). The driving tool N is supplied from the magazine 8 into the driving passage 2a in a posture extending vertically one by one. A contact arm 3 that can slide vertically is provided at the lower part of the driving nose portion 2. The contact arm 3 moves upward by coming into contact with the material to be driven W.

[0025] As shown in FIG. 3, a vertically long driver 15 is coupled to the lower surface of the piston 13. The lower part of the driver 15 enters into the driving passage 2a. The driver 15 moves downward in the driving passage 2a by the gas pressure in the accumulator chamber 14 acting on the upper surface of the piston 13. The lower end of the driver 15 strikes one driving tool N supplied into the driving passage 2a. The struck driving tool N is ejected from the ejection port 2b of the driving nose portion 2. The ejected driving tool N is driven into the material W to be driven. A lower end damper 17 for absorbing the impact at the lower moving end of the piston 13 is disposed at the lower part of the cylinder 12.

[0026] As shown in FIG. 3, a plurality of engaged portions 16 are provided on the right side portion of the driver 15. In the present embodiment, ten engaged portions 16 are arranged at regular intervals in the longitudinal direction (vertical direction) of the driver 15. Each engaged portion 16 is formed in a rack tooth shape and is provided in a state of projecting rightward. The engaged portion 16 engages with an engaging portion 25 included in a lift mechanism 20 described later.

[0027] As shown in FIG. 1, a grip 4 for the user to hold is provided at the rear part of the tool body 10. A trigger 5 that the user pulls with a fingertip is provided on the lower surface of the front part of the grip 4. A battery attachment portion 6 is provided at the rear part of the grip 4. A battery pack 7 can be detachably attached to the rear surface of the battery attachment portion 6. The battery pack 7 can be repeatedly charged with a charger prepared separately after being removed from the battery attachment portion 6. The battery pack 7 can be diverted as a power source for other power tools. The battery pack 7 operates as a power source for supplying power to a drive unit 30 described later.

[0028] As shown in FIG. 3, a lift mechanism 20 is coupled to the right side portion of the driving nose portion 2. The lift mechanism 20 has a function of returning the piston 13 and the driver 15 upward integrally after the strike. When the piston 13 is returned upward by the lift mechanism 20, the gas pressure in the accumulator chamber 14 is increased.

[0029] As shown in FIG. 1, a drive unit 30 for operating the lift mechanism 20 is arranged in parallel at the rear of the lift mechanism 20. The lift mechanism 20 and the drive unit 30 are housed in a substantially cylindrical drive unit case 11a. The drive unit case 11a connects the lower part of the main body housing 11 and the lower part of the battery attachment part 6. The drive unit case 11a is provided integrally with the main body housing 11.

[0030] As shown in FIG. 2, the drive unit 30 has an electric motor 31 as a drive source. The electric motor 31 is housed in a posture such that the axis of the output shaft 31a (motor axis J) is along the front-rear direction orthogonal to the driving direction (the direction orthogonal to the paper surface in FIG. 2). The electric motor 31 is activated by pulling the trigger 5 using the power of the battery pack 7 as a power source.

[0031] As shown in FIG. 2, the output shaft 31a of the electric motor 31 is rotatably supported by the drive unit case 11a via bearings 31b and 31c. The front part of the output shaft 31a is connected to a reduction gear train 32. The reduction gear train 32 is supported on the inner peripheral side of a substantially cylindrical gear train case 32a housed in the drive unit case 11a. Three planetary gear trains are used for the reduction gear train 32. The three planetary gear trains are coaxial with each other and arranged coaxially with the motor axis J. The rotational output of the electric motor 31 is reduced by the reduction gear train 32 including the three planetary gear trains and output to the front lift mechanism 20.

[0032] As shown in FIG. 2, the lift mechanism 20 has a rotating shaft 21 connected to a reduction gear train 32 and a wheel 22 supported by the rotating shaft 21. The lift mechanism 20 is housed in a substantially cylindrical mechanism case 29 housed in a drive unit case 11a. The rotation axis 21c of the rotating shaft 21 coincides with the motor axis J. The front portion of the mechanism case 29 is closed by a lid portion 29a. The front end of the rotating shaft 21 is rotatably supported by a bearing 26 held by the mechanism case 29 via the lid portion 29a. The rear end of the rotating shaft 21 is supported by the carrier of the final stage of the reduction gear train 32. The carrier of the final stage of the reduction gear train 32 is rotatably supported by the mechanism case 29 via a bearing 27 provided on the outer peripheral side. When the electric motor 31 is activated, the rotating shaft 21 and the wheel 22 of the lift mechanism 20 rotate integrally in the direction of arrow R shown in FIG. 3 (counterclockwise in FIG. 3).

[0033] As shown in FIGS. 5 and 6, a support member 21a for supporting the wheel 22 is provided at the center in the front-rear direction of the rotating shaft 21. The support member 21a is generally cylindrical, but has a pair of support planes 21b that extend in the radial direction and are parallel to each other. The support member 21a has a spring housing portion 21e between the pair of support planes 21b. The spring housing portion 21e is recessed along the extending direction of the pair of support planes 21b. The spring housing portion 21e opens at the end face of the support member 21a on the initial position direction side. A compression spring 24 for urging the wheel 22 in the radial direction is housed in the spring housing portion 21e.

[0034] As shown in FIGS. 4 and 5, a flange portion 21d is provided at the rear portion of the rotating shaft 21. The flange portion 21d projects in a disk shape radially outward from the support member 21a behind the support member 21a. The front surface of the flange portion 21d abuts against the rear surface of the wheel 22. A lid member 28 is attached to the front portion of the rotating shaft 21 in front of the support member 21a. The lid member 28 is provided in a disk shape having substantially the same diameter as the outer peripheral edge of the wheel 22. The lid member 28 is attached in front of the wheel 22 attached to the support member 21a. The rear surface of the lid member 28 abuts against the front surface of the wheel 22. The wheel 22 is restricted from moving in the front-rear direction by being sandwiched between the flange portion 21d and the lid member 28.

[0035] As shown in FIGS. 5 to 7, a mounting hole 23 into which the support member 21a can be inserted is provided at the center of the wheel 22. On the inner wall surface of the mounting hole 23, a pair of slide surfaces 23a extending in the radial direction and parallel to each other are provided. The distance between the pair of slide surfaces 23a is substantially the same as the distance between the pair of support planes 21b provided on the support member 21a. By inserting the support member 21a into the mounting hole 23, each slide surface 23a and each support plane 21b face and contact each other. When the slide surface 23a is in sliding contact with the support plane 21b, the wheel 22 is displaced in a certain range in the radial direction with respect to the rotation axis 21. As shown in FIGS. 5 and 6, the position of the wheel when the center 22g of the wheel 22 is located on the axis 21c of the rotation axis 21 is referred to as the initial position. As shown in FIG. 7, the position of the wheel in a state where the center 22g of the wheel 22 is deviated from the axis 21c of the rotation axis 21 is referred to as the eccentric position.

[0036] As shown in FIGS. 5 to 7, the compression spring 24 housed in the spring housing portion 21e of the support member 21a biases the wall surface of the mounting hole 23 in the radial direction of the wheel 22. The wheel 22 is biased from the eccentric position toward the initial position with respect to the support member 21a. Therefore, when no external force acts on the wheel 22, the wheel 22 is held in the initial position. When a certain or more external force in the direction toward the eccentric position acts on the wheel 22, the wheel 22 moves from the initial position to the eccentric position against the biasing force of the compression spring 24.

[0037] As shown in FIGS. 4 to 6, a plurality of engaging portions 25 are mounted along the outer peripheral edge of the wheel 22. In the present embodiment, for example, 10 engaging portions 25 are provided. A cylindrical shaft member (pin) is used for each engaging portion 25.

[0038] As shown in Fig. 3, the left part of the wheel 22 enters the driving passage 2a through a window 29b provided in the mechanism case 29. In the driving passage 2a, each engaging portion 25 of the wheel 22 is engaged with an engaged portion 16 of the driver 15. With at least one of the engaging portions 25 engaged with the engaged portion 16 of the driver 15, the wheel 22 is rotated in the direction of arrow R. As a result, the driver 15 and the piston 13 are returned upward.

[0039] As shown in Figs. 4 and 5, the wheel 22 has a front flange portion 22a and a rear flange portion 22b that are parallel to each other with a constant interval in the front-rear direction. The front flange portion 22a and the rear flange portion are formed so that their radially protruding shapes are the same. A plurality of circular through holes 22e are provided at predetermined positions where the engaging portions 25 are arranged on the peripheral edge of the front flange portion 22a. A plurality of circular groove holes 22f are provided on the peripheral edge of the upper surface of the rear flange portion 22b at positions arranged in parallel with the plurality of through holes 22e in the front-rear direction. Each through hole 22e and each groove hole 22f have substantially the same diameter as the engaging portion 25 to be inserted. The plurality of engaging portions 25 are inserted into the corresponding through holes 22e and groove holes 22f, and a lid member 28 is attached to the front portion of the rotating shaft 21. Thereby, the plurality of engaging portions 25 are held across between the peripheral edge of the front flange portion 22a and the peripheral edge of the rear flange portion 22b.

[0040] Each engaging portion 25 shown in Fig. 3 is supported by the wheel 22 so as to be rotatable about its respective axis center. Therefore, it is possible to suppress the continuous contact of a predetermined region on the outer peripheral surface of each engaging portion 25 with the engaged portion 16. Thereby, wear of the engaging portion 25 can be suppressed.

[0041] As shown in Fig. 6, the distances of the plurality of engaging portions 25 from the center 22g of the wheel 22 are different from each other. Also, the plurality of engaging portions 25 are arranged at predetermined angular intervals in the circumferential direction about the center 22g. In this embodiment, ten engaging portions 25 are arranged at predetermined intervals in a range of approximately 3 / 4 of the circumference of the wheel 22. No engaging portion 25 is arranged in a range of approximately 1 / 4 of the wheel 22. Hereinafter, the circumferential range where no engaging portion 25 is arranged is referred to as a relief portion 22h.

[0042] As shown in FIG. 6, regarding the rotation direction of the wheel 22, the engaging portion 25 immediately after the relief portion 22h is referred to as the first engaging portion 25a. The center of the first engaging portion 25a is located on a reference circle C at a reference distance from the axis 21c of the rotation axis 21 when the wheel 22 is in the initial position. Regarding the rotation direction of the wheel 22, the two engaging portions 25 arranged immediately after the first engaging portion 25a are referred to as outer position engaging portions 25b. The centers of the outer position engaging portions 25b are located radially outward of the reference circle C. Regarding the rotation direction of the wheel 22, the one engaging portion 25 arranged immediately after the two outer position engaging portions 25b is referred to as the first intermediate engaging portion 25d. The center of the first intermediate engaging portion 25d is located on the reference circle C.

[0043] As shown in FIG. 6, regarding the rotation direction of the wheel 22, the three engaging portions 25 arranged immediately after the first intermediate engaging portion 25d are referred to as inner position engaging portions 25c. The centers of the inner position engaging portions 25c are located radially inward of the reference circle C. Regarding the rotation direction of the wheel 22, the one engaging portion 25 arranged immediately after the three inner position engaging portions 25c is referred to as the second intermediate engaging portion 25e. The centers of the two engaging portions between the second intermediate engaging portion 25e and the relief portion 22h are located on the reference circle C.

[0044] As shown in FIG. 6, among the plurality of engaging portions 25, two adjacent engaging portions 25 have an angle with respect to the center 22g of the wheel 22. Each angle is referred to as angle A1, A2, A3, A4, A5, A6, A7, A8, A9 in the order of the rotation direction of the wheel 22 starting from the first engaging portion 25a. The total of angles A1, A2, A3 is approximately 90°. The total of angles A1 to A6 is approximately 180°. The total of angles A1 to A7 is greater than 180°. Therefore, in the range of 0° to 90° in the rotation direction of the wheel 22 starting from the first engaging portion 25a, the outer position engaging portion 25b, and the first engaging portion 25a and the first intermediate engaging portion 25d on the reference circle C are arranged. In the range of 90° to 180° in the rotation direction of the wheel 22 starting from the first engaging portion 25a, the inner position engaging portion 25c, and the first intermediate engaging portion 25d on the reference circle C are arranged. The engaging portions 25 in the range of 180° to 360° in the rotation direction of the wheel 22 starting from the first engaging portion 25a are all arranged on the reference circle C.

[0045] As shown in FIG. 6, each of the angles A1 to A9 is provided such that the longer the distance from the center of each engaging portion 25 forming the angle to the center 22g of the wheel 22, the smaller the angle, and the shorter the distance, the larger the angle. For example, the angles A1, A2, and A3, where one of the two engaging portions 25 forming the angle is the outer position engaging portion 25b, are smaller than the angles A8 and A9, where both of the two engaging portions 25 forming the angle are on the reference circle C. The angles A1, A2, and A3 correspond to the first angle in the present embodiment. The angles A4, A5, A6, and A7, where one of the two engaging portions 25 forming the angle is the inner position engaging portion 25c, are larger than the angles A8 and A9. The angles A4, A5, A6, and A7 correspond to the second angle in the present embodiment. The angles A8 and A9 are substantially the same size. The angle A2, where both of the two engaging portions 25 forming the angle are the outer position engaging portion 25b, is smaller than the angles A1 and A3, where one of the two engaging portions 25 forming the angle is the outer position engaging portion 25b. The angles A5 and A6, where both of the two engaging portions 25 forming the angle are the inner position engaging portion 25c, are larger than the angles A4 and A7, where one of the two engaging portions 25 forming the angle is the inner position engaging portion 25c.

[0046] As shown in FIG. 6, the wheel 22 has a large-diameter outer peripheral edge 22c that is located radially outside the outer position engaging portion 25b in the region where the outer position engaging portion 25b is provided. The wheel 22 has a small-diameter outer peripheral edge 22d that is located radially outside the inner position engaging portion 25c in the region where the inner position engaging portion 25c is provided. The small-diameter outer peripheral edge 22d is located radially inside the outermost peripheral end of the outer position engaging portion 25b starting from the center 22g of the wheel 22. The large-diameter outer peripheral edge 22c is located radially outside the small-diameter outer peripheral edge 22d starting from the center 22g of the wheel 22.

[0047] Next, a series of flows of the driving operation of the driving tool 1 will be described. FIG. 3 shows the standby states of the piston 13 and the driver 15. The driver 15 and the piston 13 in the standby state are held in a stopped state at a standby position slightly below the upper moving end. In this standby state, the engaging portion 25 immediately before the relief portion 22h is engaged with the lower surface of the engaged portion 16 at the lowermost end of the driver 15.

[0048] In the standby state, when the contact arm 3 shown in FIG. 1 moves upward and the trigger 5 is pulled, the electric motor 31 is started. When the electric motor 31 is started, the wheel 22 shown in FIG. 3 rotates in the rotation direction indicated by the arrow R. The engaging portion 25 immediately before the relief portion 22h moves the engaged portion 16 at the lowermost end of the driver 15 upward. As a result, the piston 13 and the driver 15 move upward from the standby position to the upper end position. When the driver 15 moves to the upper end position, the driving tool N (see FIG. 1) is supplied from the magazine 8 into the driving passage 2a. When reaching the state immediately before driving at the upper end, the engaging portion 25 of the wheel 22 disengages from the engaged portion 16 of the driver 15. As a result, the piston 13 and the driver 15 move downward due to the gas pressure in the accumulator chamber 14. When the driver 15 moves downward in the driving passage 2a, one driving tool N is struck.

[0049] When the driver 15 moves downward, all the engaging portions 25 of the wheel 22 exit from the driving passage 2a and are located in the mechanism case 29. Therefore, the relief portion 22h of the wheel 22 is located in the driving passage 2a. This avoids the interference of the engaging portion 25 with the engaged portion 16 of the driver 15, and a smooth driving operation is performed.

[0050] After the driving tool N is struck, when the driver 15 reaches the lower end position, the wheel 22 continues to rotate in the direction of the arrow R. As shown in FIG. 8, the first engaging portion 25a is engaged with the lower surface of the first engaged portion 16a at the uppermost end of the engaged portion 16 of the driver 15. As a result, a return operation for moving the piston 13 and the driver 15 upward in the reverse driving direction is started. At the start of the return operation, the wheel 22 is biased by the compression spring 24 toward the initial position (toward the left driver 15 side). Therefore, the center 22g of the wheel is located on the axis 21c of the rotation shaft 21.

[0051] In the state shown in FIG. 8, the wheel 22 is in a first state where it can move from the initial position to the eccentric position by receiving an external force that exceeds the biasing force of the compression spring 24 toward the right. However, although a force in the driving direction acts on the first engaging portion 25a that engages with the first engaged portion 16a, almost no force in the left-right direction orthogonal to the driving direction acts. Therefore, the wheel 22 is biased leftward by the compression spring 24 and held at the initial position.

[0052] Subsequently, when the wheel 22 rotates, the two outer position engaging portions 25b sequentially engage with the lower surface of the engaged portion 16. The outer position engaging portions 25b are located radially outward of the first engaging portion 25a with respect to the center 22g of the wheel 22. Therefore, in the state where the wheel 22 is located at the initial position, the outer position engaging portion 25b and the bottom of the engaged portion 16 interfere with each other. To avoid the interference between the outer position engaging portion 25b and the bottom of the engaged portion 16, the center 22g of the wheel 22 moves away from the driver 15. As a result, the wheel 22 is in a second state where it is located at the eccentric position on the right against the biasing force of the compression spring 24. The center 22g of the wheel 22 is located to the right of the axis 21c of the rotation shaft 21.

[0053] After the two outer position engaging portions 25b, the first intermediate engaging portion 25d engages with the lower surface of the engaged portion 16. In this state, the initial position of the wheel 22 is located above the eccentric position of the wheel 22. In this state, the first intermediate engaging portion 25d receives a force of, for example, about 10 kN downward from the engaged portion 16. Therefore, the wheel 22 is in a second state where it is pushed downward against the biasing force of the compression spring 24 and located at the eccentric position.

[0054] As shown in Fig. 9, after the first intermediate engaging portion 25d, three inward position engaging portions 25c sequentially engage with the lower surface of the engaged portion 16. In this state, the initial position of the wheel 22 is located above and to the right of the eccentric position of the wheel 22. In this state, the inward position engaging portion 25c receives a downward force of, for example, about 10 kN from the engaged portion 16. Therefore, the wheel 22 is pushed downward against the biasing force of the compression spring 24 and is in a second state where it is located at the lower left eccentric position. The inward position engaging portion 25c is located radially inward of the first engaging portion 25a with respect to the center 22g of the wheel 22. Therefore, in a state where the wheel 22 is located at the left eccentric position, the inward position engaging portion 25c and the bottom of the engaged portion 16 can engage without interfering with each other.

[0055] As shown in Fig. 10, after the three inward position engaging portions 25c, the second intermediate engaging portion 25e engages with the lower surface of the engaged portion 16. In this state, the initial position of the wheel 22 is located to the right of the eccentric position of the wheel 22. In this state, a driving direction force acts on the second intermediate engaging portion 25e from the engaged portion 16, and a component force directed from the eccentric position to the initial position is generated by the support plane 21b. Therefore, the wheel 22 is biased toward the right and held at the initial position.

[0056] As shown in Fig. 3, when the engaging portion 25 immediately before the relief portion 22h engages with the lower surface of the engaged portion 16 at the lowermost end, the piston 13 and the driver 15 reach the standby position described above. For example, by appropriately controlling the time from the start of the electric motor 31, the electric motor 31 (see Fig. 2) is stopped when the driver 15 and the piston 13 reach the standby position. Thus, a series of driving operations is completed.

[0057] As shown in Fig. 11, there may be a case where the driving tool N (see Fig. 1) struck by the downward movement of the driver 15 cannot be normally driven into the material W to be driven. In this case, a state of nail jamming or insufficient driving occurs in which the deformed driving tool N is clogged in the driving passage 2a. In this case, the driver 15 stops at a position above the lower end. Even when the driver 15 is stopped, the rotation state of the wheel 22 continues. Therefore, a relative position shift occurs between the engaging portion 25 and the engaged portion 16 that engages with the engaging portion 25 during normal operation.

[0058] For example, as shown in Fig. 11, the first engaging portion 25a does not enter the lower surface of the first engaged portion 16a, and a state occurs in which it interferes with the tip of the engaged portion 16 below the first engaged portion 16a. In this state, the initial position of the wheel 22 is located on the lower left side of the eccentric position of the wheel 22. When the wheel 22 is rotated in the direction of arrow R in this state, a force is generated from the interfering engaged portion 16 toward the first engaged portion 16a to the right. Therefore, as shown in Fig. 12, the wheel 22 moves to the eccentric position on the right against the biasing force of the compression spring 24. As a result, the first engaging portion 25a retreats to the right from the interfering engaged portion 16, and the interference state is eliminated.

[0059] As shown in Fig. 13, as the rotation state of the wheel 22 continues, the first engaging portion 25a moves toward the engaged portion 16 located above one of the interfering engaged portions 16. Also, the force that pushes the first engaging portion 25a of the engaged portion 16 to the right is eliminated. Therefore, the wheel 22 is biased by the compression spring 24 and moves to the initial position on the left. As a result, the first engaging portion 25a engages with the lower surface of the engaged portion 16. Therefore, the rotation of the wheel 22 can move the piston 13 and the driver 15 upward. When the wheel 22 rotates to the standby position, the electric motor 31 (see Fig. 2) stops. As a result, the clogged driving tool N (see Fig. 1) can be removed from the driving passage 2a while the downward movement of the driver 15 is blocked.

[0060] As described above, the driving tool 1 has a piston 13 that moves in the driving direction by gas pressure as shown in FIG. 8. The driving tool 1 has a driver 15 that extends in the driving direction from the piston 13 and includes a plurality of engaged portions 16 formed side by side in the driving direction. The driving tool 1 has a lift mechanism 20 that moves the driver 15 in the reverse driving direction. The lift mechanism 20 has a rotation shaft 21 and a wheel 22 that rotates together with the rotation shaft 21 about the rotation shaft 21. The lift mechanism 20 has a plurality of engaging portions 25 that are arranged along the outer periphery of the wheel 22 and engage with the engaged portions 16 of the driver 15. The lift mechanism 20 has a support member 21a that is provided on the rotation shaft 21 and supports the wheel 22 so as to be radially movable between an initial position and an eccentric position with respect to the rotation shaft 21. The lift mechanism 20 is displaced between a first state in which the wheel 22 engages with the driver 15 at the initial position and can retract to the eccentric position when moving the driver 15 in the reverse driving direction, and a second state in which the wheel 22 engages with the driver 15 at the eccentric position.

[0061] Therefore, when the return operation of the driver 15 operates normally, the wheel 22 is located at the initial position or the eccentric position according to its rotation angle. Regardless of whether the wheel 22 is located at the initial position or the eccentric position, the engaging portion 25 of the lift mechanism 20 engages with the engaged portion 16 of the driver 15. Therefore, the return operation of moving the driver 15 upward can be continued smoothly. For example, when a nail jam or the like occurs during the driving operation and the driver 15 stops at an abnormal position, the engaging portion 25 may not engage with the normal engaged portion 16, and the engaging portion 25 and the engaged portion 16 may interfere with each other. In this case, the wheel 22 can retract from the initial position to the eccentric position. Therefore, the interference between the engaging portion 25 and the engaged portion 16 can be eliminated. After the interference between the engaging portion 25 and the engaged portion 16 is eliminated, the wheel 22 moves to the initial position or the eccentric position, and the engaging portion 25 engages with the engaged portion 16. Therefore, the return operation of moving the driver 15 upward can be continued smoothly.

[0062] As shown in Fig. 8, the driving tool 1 has a compression spring 24 that biases the wheel 22 from an eccentric position to an initial position. Therefore, when the wheel 22 is in the initial position and the engaging portion 25 is properly engaged with the engaged portion 16, it is possible to prevent the engaging portion 25 from accidentally retracting from the engaged portion 16. When the engaging portion 25 does not engage properly with the engaged portion 16 and there is interference, after moving the wheel 22 from the initial position to the eccentric position to eliminate the interference between the engaging portion 25 and the engaged portion 16, the wheel 22 can be quickly returned to the initial position. Therefore, the engaging portion 25 and the engaged portion 16 can be quickly engaged. As a result, the return operation of the driver 15 can be quickly restored.

[0063] As shown in Fig. 8, the support member 21a supports the wheel 22 so that it can reciprocate linearly with respect to the rotation axis 21. Therefore, the wheel 22 can move in a direction away from the driver 15 only within a predetermined range of rotation angles. Therefore, within the range where the wheel 22 is at a predetermined rotation angle, the interference between the engaging portion 25 and the engaged portion 16 can be eliminated. Outside the range of the predetermined rotation angle, the wheel 22 cannot move away from the driver 15. Therefore, it is possible to prevent the engaging portion 25 from retracting from the engaged portion 16. As a result, the return operation of the driver 15 can be continued smoothly.

[0064] As shown in Fig. 6, the support member 21a has a pair of support planes 21b that extend in the radial direction and are parallel to each other. The wheel 22 has a mounting hole 23 that is inserted with the support member 21a and has a pair of slide surfaces 23a that face each of the pair of support planes 21b and extend in the radial direction. Therefore, by utilizing the support structure of the wheel 22 supported by the rotation axis 21, the wheel 22 can be moved between the initial position and the eccentric position. Therefore, a compact moving structure for supporting the wheel 22 so that it can move in the radial direction can be formed.

[0065] As shown in FIG. 8, one of the plurality of engaging portions 25 is a first engaging portion 25a that first engages with the engaged portion 16 when moving the driver 15 in the counter-punching direction. The first engaging portion 25a is located on a reference circle C at a reference distance from the axis 21c of the rotation axis 21 when the wheel 22 is in the initial position (see FIG. 6). Therefore, the arrangement of each engaging portion 25 that enables the return operation of the driver 15 to be continued smoothly can be easily set based on the reference circle C.

[0066] As shown in FIG. 6, the plurality of engaging portions 25 includes at least one outer position engaging portion 25b located radially outward of the reference circle C within a range of 0° to 90° in the rotational direction of the wheel 22 starting from the first engaging portion 25a. The plurality of engaging portions 25 includes at least one inner position engaging portion 25c located radially inward of the reference circle C within a range of 90° to 180° in the rotational direction of the wheel 22 starting from the first engaging portion 25a.

[0067] Therefore, when the outer position engaging portion 25b engages with the engaged portion 16, the wheel 22 is pushed by the engaged portion 16 and moves from the initial position to the eccentric position. The wheel 22 moves from the initial position to the eccentric position within a range where the rotation angle is 0° to 90°, with the rotation angle at the start of engagement between the first engaging portion 25a and the engaged portion 16 being 0°. When the rotation angle is within the range of 90° to 180° and the wheel 22 is in the eccentric position, the engaged portion 16 enters radially inward of the reference circle C. Therefore, by providing the inner position engaging portion 25c arranged radially inward of the reference circle C, the inner position engaging portion 25c and the engaged portion 16 can be engaged without interfering with each other. Thus, when the wheel 22 moves from the initial position to the eccentric position and when in the eccentric position, the return operation of the driver 15 can be continued smoothly.

[0068] As shown in Fig. 6, a plurality of engaging portions 25 are located on or radially outside the reference circle C within a range of 0° to 90° in the rotational direction of the wheel 22 starting from the first engaging portion 25a. They are located on or radially inside the reference circle C within a range of 90° to 180° in the rotational direction of the wheel 22 starting from the first engaging portion 25a. Therefore, taking the rotational angle when the first engaging portion 25a starts engaging with the engaged portion 16 as 0°, within the range of the rotational angle from 0° to 90°, the wheel 22 can be continuously moved from the initial position to the eccentric position. Within the range of the rotational angle from 90° to 180° and in the state where the wheel 22 is located at the eccentric position, the plurality of engaging portions 25 and the plurality of engaged portions 16 can be engaged without interfering with each other.

[0069] As shown in Fig. 6, a plurality of engaging portions 25 are located on the reference circle C within a range of 180° to 360° in the rotational direction of the wheel 22 starting from the first engaging portion 25a. Therefore, taking the rotational angle when the first engaging portion 25a starts engaging with the engaged portion 16 as 0°, within the range of the rotational angle from 180° to 360°, the wheel 22 is located at the initial position and does not move to the eccentric position. Therefore, by arranging the plurality of engaging portions 25 on the reference circle C, the plurality of engaging portions 25 can be provided so as not to retract and not interfere with the engaged portion 16.

[0070] As shown in Fig. 6, two of the plurality of adjacent engaging portions 25 on the radially outer side of the reference circle C have first angles A1, A2, A3 with respect to the center of the rotation axis 21. Two of the plurality of adjacent engaging portions 25 on the radially inner side of the reference circle C have second angles A4, A5, A6, A7 larger than the first angles A1, A2, A3 with respect to the center of the rotation axis 21. Therefore, the amount of movement in the counterpunching direction while each engaging portion 25 is engaged with the engaged portion 16 can be made substantially constant. Therefore, for example, the engaging portions 25 can be accurately engaged with a plurality of engaged portions 16 arranged at equal intervals in the driving direction. Thereby, the driver 15 can be smoothly moved upward.

[0071] As shown in FIG. 8, the wheel 22 has a small-diameter outer peripheral edge 22d located on the inner peripheral side of the outermost peripheral end of the outer position engaging portion 25b, and a large-diameter outer peripheral edge 22c located on the outer peripheral side of the small-diameter outer peripheral edge 22d in a region corresponding to the outer position engaging portion 25b. Therefore, the outer peripheral edge of the wheel 22 can be formed compactly. The wheel 22 moves radially between an initial position and an eccentric position with respect to the rotation axis 21 within the mechanism case 29 that houses the lift mechanism 20. By forming the outer peripheral edge of the wheel 22 compactly, the mechanism case 29 that houses the lift mechanism 20 can be formed compactly.

[0072] Various modifications can be made to the embodiments described above. For example, in the lift mechanism 20, although the wheel 22 having ten engaging portions 25 and the driver 15 having ten engaged portions 16 are exemplified, the number of the engaging portions 25 and the engaged portions 16 is not limited to ten. The number of the engaging portions 25 and the engaged portions 16 is appropriately set according to factors such as the stroke of the driver 15 and the size of the tool body 10.

[0073] Although the pin-shaped engaging portion 25 and the rack-tooth-shaped engaged portion 16 are exemplified, the shapes of the engaging portion 25 and the engaged portion 16 are not limited thereto. For example, a plurality of engaging portions 25 may be provided in a pinion-tooth shape formed along the outer peripheral edge of the wheel 22. Although the plurality of engaged portions 16 are exemplified as a plurality of engaged portions 16 formed at equal intervals in the longitudinal direction of the driver 15, the plurality of engaged portions 16 may be formed at unequal intervals.

[0074] Although the compression spring 24 is exemplified as a biasing member that biases the wheel 22 toward the initial position, it may be changed to other biasing members such as a leaf spring or urethane rubber. The biasing member that biases the wheel 22 toward the initial position may also be configured to be disposed outside the mounting hole 23.

[0075] Taking the first engaging portion 25a as a starting point, within the range of 0° to 90° in the rotational direction of the wheel 22, a configuration is exemplified in which all the engaging portions 25 are arranged on the reference circle C or radially outward of the reference circle C. Instead of this, for example, within the same range, a configuration in which only one engaging portion 25 is arranged radially outward of the reference circle C may be adopted.

[0076] Taking the first engaging portion 25a as a starting point, within the range of 90° to 180° in the rotational direction of the wheel 22, a configuration is exemplified in which all the engaging portions 25 are arranged on the reference circle C or radially inward of the reference circle C. Instead of this, for example, within the same range, a configuration in which only one engaging portion 25 is arranged radially inward of the reference circle C may be adopted.

[0077] A configuration is exemplified in which the axis 21c of the rotation axis 21 of the lift mechanism 20 is coaxial with the motor axis J. Instead of this, for example, the axis 21c may extend parallel to the motor axis J at a position deviated from the motor axis J, or the axis 21c may extend in a direction intersecting the motor axis J.

Explanation of Signs

[0078] 1... Driving tool 2... Driving nose portion, 2a... Driving passage, 2b... Injection port 3... Contact arm 4... Grip 5... Trigger 6... Battery mounting portion 7... Battery pack 8... Magazine 10... Tool body 11... Main body housing, 11a... Driving unit case 12... Cylinder 13... Piston 14... Accumulator chamber 15... Driver 16... Engaged portion, 16a... First engaged portion 17... Lower end damper 20... Lift mechanism 21... Rotation axis, 21a... Support member, 21b... Support plane, 21c... Axis 21d… flange part, 21e… spring housing part 22… wheel, 22a… front flange part, 22b… rear flange part, 22c… large-diameter outer peripheral edge 22d… small-diameter outer peripheral edge, 22e… through hole, 22f… groove hole, 22g… center 22h… relief part 23… mounting hole, 23a… sliding surface 24… compression spring (biasing member) 25… engaging part 25a… first engaging part 25b… outer position engaging part 25c… inner position engaging part 25d… first intermediate engaging part, 25e… second intermediate engaging part 26, 27… bearings 28… cover member 29… mechanism case, 29a… cover part, 29b… window part 30… driving part 31… electric motor, 31a… output shaft, 31b, 31c… bearings 32… reduction gear train, 32a… gear train case N… driving tool W… material to be driven J… motor axis C… reference circle A1~A9… angles

Claims

1. A driving tool, comprising: a piston that moves in a driving direction by gas pressure; a driver extending from the piston in the driving direction and having a plurality of engaged portions formed side by side in the driving direction; a lift mechanism for moving the driver in a reverse driving direction, wherein the lift mechanism has a rotation axis, a wheel that rotates together with the rotation axis about the rotation axis, a plurality of engaging portions arranged along an outer circumference of the wheel and engaging with the engaged portions of the driver, and a support member provided on the rotation axis and supporting the wheel so as to be radially movable between an initial position and an eccentric position with respect to the rotation axis. When the driver is moved in the reverse driving direction, the wheel engages with the driver at the initial position and can retract to the eccentric position, and the wheel is displaced to a second state in which the wheel engages with the driver at the eccentric position; one of the plurality of engaging portions is a first engaging portion that first engages with the engaged portion when the driver is moved in the reverse driving direction, and is located on a reference circle at a reference distance from an axis center of the rotation axis when the wheel is located at the initial position; the plurality of engaging portions include at least one outer position engaging portion located radially outside the reference circle and at least one inner position engaging portion located radially inside the reference circle; two of the plurality of engaging portions adjacent to each other radially outside the reference circle have a first angle with respect to a center of the rotation axis, and two of the plurality of engaging portions adjacent to each other radially inside the reference circle have a second angle larger than the first angle with respect to the center of the rotation axis. A driving tool.

2. The driving tool according to claim 1, further comprising: a biasing member that biases the wheel from the eccentric position to the initial position.

3. The driving tool according to claim 1 or 2, wherein: the support member supports the wheel to be linearly reciprocally movable with respect to the rotation axis.

4. The driving tool according to claim 3, wherein: the support member has a pair of support planes extending in a radial direction and parallel to each other; the wheel has a mounting hole including a pair of slide surfaces into which the support member is inserted and facing each of the pair of support planes and extending in a radial direction.

5. The driving tool according to claim 1, wherein: The plurality of engaging portions include at least one outer-position engaging portion located radially outward of the reference circle within a range of 0° to 90° in the rotational direction of the wheel starting from the first engaging portion, and at least one inner-position engaging portion located radially inward of the reference circle within a range of 90° to 180° in the rotational direction of the wheel starting from the first engaging portion. The driving tool.

6. The driving tool according to claim 5, wherein The plurality of engaging portions are located on or radially outward of the reference circle within a range of 0° to 90° in the rotational direction of the wheel starting from the first engaging portion, and are located on or radially inward of the reference circle within a range of 90° to 180° in the rotational direction of the wheel starting from the first engaging portion. Driving tool.

7. The driving tool according to claim 5 or 6, wherein The plurality of engaging portions are driving tools located on the reference circle within a range of 180° to 360° in the rotational direction of the wheel starting from the first engaging portion.

8. The driving tool according to any one of claims 5 to 7, wherein The wheel has a small-diameter outer peripheral edge located on the inner peripheral side of the outermost peripheral end of the outer-position engaging portion, and a large-diameter outer peripheral edge located on the outer peripheral side of the small-diameter outer peripheral edge in a region corresponding to the outer-position engaging portion. Driving tool.

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