Electric tool

Abstract

To provide an electric tool having a rotation direction restricting mechanism that can more surely restrict a direction of rotation that is caused by output of a motor only to one direction.SOLUTION: An electric tool has a motor and also has a rotation direction restricting mechanism 40 that restricts a direction of rotation that is caused by output of the motor. The rotation direction restricting mechanism 40 has an outer wheel 41. The rotation direction restricting mechanism 40 has an inner peripheral member 42 provided at an inner periphery side of the outer wheel 41. The rotation direction restricting mechanism 40 has a plurality of cam surfaces 43 recessed in an outer peripheral surface 42a of the inner peripheral member 42. The rotation direction restricting mechanism 40 has lock members 44, arranged movably in the cam surfaces 43, which allow the outer wheel 41 and the inner peripheral member 42 to relatively rotate in a first direction and restrict the outer wheel and the inner peripheral member from relatively rotating in a second direction R2. The rotation direction restricting mechanism 40 has protrusions (eccentric mechanisms) 45 that make the outer wheel 41 and the inner peripheral member 42 eccentric from each other.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a power tool driven by the output of a motor.

Background Art

[0002] For example, as one of the power tools, Patent Document 1 discloses a so-called gas spring type driving tool. The driving tool has a driver that strikes a driving tool, a lift mechanism that moves the driver to a standby position or top dead center, and a motor as a drive source for the lift mechanism. The driving tool has a cylinder extending in the driving direction and a piston that is movable within the cylinder and is connected to the driver. When the driver and the piston are moved in the counter-driving direction by the lift mechanism, the gas pressure enclosed in the pressure accumulation chamber above the cylinder increases. The driver moves in the driving direction using this gas pressure as a driving force to strike the driving tool.

[0003] The lift mechanism moves the driver and the piston in the counter-driving direction, for example, by rotating in a first direction. Therefore, the lift mechanism receives a force that tries to rotate it in a second direction opposite to the first direction by the gas pressure in the pressure accumulation chamber. If the lift mechanism is rotatable freely in the second direction, the driver and the piston cannot be held against the gas pressure. Therefore, in any region from the motor to the lift mechanism, a one-way clutch mechanism, for example, is provided as a mechanism that regulates the rotation direction to one direction.

[0004] The one-way clutch mechanism has, for example, a substantially disk-shaped inner peripheral member that transmits rotational power, and a substantially cylindrical outer ring that surrounds the outer periphery of the inner peripheral member. A cam surface is recessed in either the outer peripheral surface of the inner peripheral member or the outer peripheral surface of the outer ring. A locking member such as a cylindrical pin is inserted into the cam surface. The cam surface is provided with a wide width in the radial direction at one end side in the circumferential direction and a narrow width in the radial direction at the other end side in the circumferential direction. When the inner peripheral member rotates in the first direction, the locking member moves to the wider side of the width of the cam surface. Therefore, the inner peripheral member can rotate in the first direction without being restricted. When the inner peripheral member attempts to rotate in the second direction opposite to the first direction, the locking member moves to the narrower side of the width of the cam surface. Therefore, the locking member is sandwiched between the inner peripheral member and the outer ring. As a result, the rotation of the inner peripheral member in the second direction is restricted.

[0005] Each structure of the conventional one-way clutch mechanism was arranged point-symmetrically with respect to the rotation center of the inner peripheral member. In such a case, there were situations where the rotation in the second direction could not be sufficiently restricted. For example, around the one-way clutch mechanism, a gear train etc. coated with grease is provided. For example, due to heat etc. during driving, grease enters the cam surface of the one-way clutch mechanism, cools and solidifies, or its viscosity increases. At this time, the grease may prevent the movement of the locking member and the locking member may not be able to move to the narrower side of the width of the cam surface. When the movement of the locking member is restricted in this way, the rotation of the inner peripheral member in the second direction cannot be restricted.

[0006] Some of the conventional one-way clutch mechanisms are provided with, for example, a spring that constantly biases the locking member to the narrower side of the width of the cam surface. However, space is required to provide a structure that constantly biases the locking member. For example, when providing a one-way clutch mechanism within a mechanism with many components such as a planetary gear mechanism, it is difficult to secure space so as not to interfere with each component. For example, if the number of gears is increased, there is not enough space to arrange a spring etc. Also, the cost increases for assembling a spring etc.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent No. 6627990 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] Therefore, there is a need for a power tool having a rotation direction regulating mechanism that can more reliably regulate the rotation direction by the output of the motor to one direction. [Means for Solving the Problems]

[0009] According to one feature of the present disclosure, a power tool has a motor. The power tool has a rotation direction regulating mechanism that regulates the rotation direction of rotation by the output of the motor. The rotation direction regulating mechanism has an outer ring. The rotation direction regulating mechanism has an inner peripheral member provided on the inner peripheral side of the outer ring. The rotation direction regulating mechanism has a plurality of cam surfaces recessed in the inner peripheral surface of the outer ring or the outer peripheral surface of the inner peripheral member. The rotation direction regulating mechanism has a lock member that is movably disposed within the cam surface and allows relative rotation of the outer ring and the inner peripheral member in a first direction and restricts relative rotation in a second direction. The rotation direction regulating mechanism has an eccentric mechanism that eccentrically positions the outer ring and the inner peripheral member relative to each other.

[0010] Therefore, by eccentrically positioning the outer ring and the inner peripheral member relative to each other by the eccentric mechanism, a part of the plurality of cam surfaces is disposed at a location where the outer ring and the inner peripheral member are in close contact in the radial direction. Therefore, at least a part of the lock member inserted into the cam surface can be in close contact with both the outer ring and the inner peripheral member. Therefore, when the outer ring and the inner peripheral member attempt to rotate relative to each other in the second direction, the lock member is surely pinched between the outer ring and the inner peripheral member. Thereby, the relative rotation direction of the outer ring and the inner peripheral member can be more reliably regulated to one direction. [Brief Description of the Drawings]

[0011]

Figure 1

Figure 2

Figure 3

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Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0012] According to another feature of the present disclosure, the power tool has a holding member surrounding the outer ring. On one of the outer ring and the holding member, a protrusion of an eccentric mechanism that protrudes toward the other and abuts against the other is provided. Therefore, with a simple structure of providing a protrusion on the outer ring or the holding member, the outer ring and the inner peripheral member can be eccentric to each other. Therefore, the rotation direction regulating mechanism can be provided without significantly changing from the conventional structure, and the rotation direction can be more reliably regulated in one direction.

[0013] According to another feature of the present disclosure, the inner peripheral member is rotatable by a motor. The outer ring has an inner peripheral surface that is eccentric with respect to the rotation center of the inner peripheral member. Therefore, for example, when the inner peripheral member rotates, the inner peripheral surface of the outer ring and the outer peripheral surface of the inner peripheral member can be mutually eccentric while giving the inner peripheral member axial symmetry. As a result, the wobbling of the inner peripheral member can be suppressed, and the rotation direction can be more reliably restricted to one direction.

[0014] According to another feature of the present disclosure, the inner peripheral member is rotatable by a motor. The inner peripheral member has an outer peripheral surface that is eccentric with respect to the rotation center of the inner peripheral member. Therefore, the outer ring can be assembled in the same manner as the conventional structure, and the inner peripheral surface of the outer ring and the outer peripheral surface of the inner peripheral member can be mutually eccentric to more reliably restrict the rotation direction to one direction.

[0015] According to another feature of the present disclosure, a cam surface is provided on the inner peripheral member. Therefore, when the inner peripheral member rotates, the locking member can be smoothly moved along the cam surface by using centrifugal force. As a result, the allowance of rotation in the first direction and the restriction of rotation in the second direction can be more reliably actuated.

[0016] According to another feature of the present disclosure, the power tool has a holding member that surrounds the outer ring and restricts the rotation of the outer ring. The inner peripheral member is rotatable by a motor. Therefore, the outer ring is provided so as not to rotate integrally with the holding member, and the inner peripheral member is provided as a component that rotates by the output of the motor. As a result, for example, a rotation direction restricting mechanism can be provided in a gear train or the like that transmits while converting the output of the motor.

[0017] According to another feature of the present disclosure, the power tool has a planetary gear mechanism that decelerates the rotation by the output of the motor. The planetary gear mechanism has planetary gears rotatably held by the inner peripheral member. Therefore, a rotation direction restricting mechanism that can more reliably restrict the rotation direction to one direction can be provided in the planetary gear mechanism with a large number of parts and little space.

[0018] According to another feature of the present disclosure, the planetary gear mechanism has an internal gear that engages with the planetary gear. The internal gear and the outer ring are arranged side by side and housed in the gear case. The outer diameter of the outer ring is smaller than the outer diameter of the internal gear. Therefore, by making the outer diameter of the outer ring smaller than the outer diameter of the internal gear, a gap can be provided between the outer diameter of the outer ring and the inner peripheral surface of the gear case. The center of the internal gear is located at the center of the gear case. Therefore, the outer ring can be eccentric with respect to the center of the internal gear by utilizing the gap.

[0019] According to another feature of the present disclosure, the power tool has a planetary gear mechanism that decelerates the rotation by the output of the motor. The planetary gear mechanism has an upstream internal gear. The planetary gear mechanism has an upstream planetary gear that engages with the upstream internal gear. The planetary gear mechanism has a downstream internal gear. The planetary gear mechanism has a downstream planetary gear that engages with the downstream internal gear. The upstream internal gear, the outer ring, and the downstream internal gear are housed in the gear case in this order. The gear case is provided with a protrusion of an eccentric mechanism that protrudes toward the outer ring and abuts against the outer ring. The protrusion makes a part of the inner diameter of the gear case smaller than the outer diameters of the upstream internal gear and the downstream internal gear.

[0020] Therefore, the outer ring can be assembled to the gear case together with the components of the planetary gear mechanism. Moreover, the protrusion of the gear case is provided so as not to interfere with members other than the outer ring, such as the upstream internal gear and the downstream internal gear. Thus, only the outer ring can be eccentric with respect to the rotation center of the inner peripheral member without preventing the drive of the planetary gear mechanism.

[0021] According to another feature of the present disclosure, the power tool has a lift mechanism that accumulates energy by the output of the motor. The power tool has a driver that moves in the driving direction by the energy accumulated in the lift mechanism to drive the driving tool. Therefore, the lift mechanism accumulates energy by rotating forward. If the lift mechanism reverses due to the accumulated energy, the accumulated energy is lost and a normal driving operation cannot be performed. By allowing the rotation direction of the lift mechanism to be only the forward rotation direction with a rotation direction regulating mechanism, it is possible to suppress the accidental loss of the accumulated energy.

[0022] According to another feature of the present disclosure, the power tool has a planetary gear mechanism that decelerates the rotation by the output of the motor. The planetary gear mechanism has an upstream internal gear. The planetary gear mechanism has an upstream planetary gear that engages with the upstream internal gear. The planetary gear mechanism has a downstream internal gear. The planetary gear mechanism has a downstream planetary gear that engages with the downstream internal gear. The downstream internal gear is provided on the downstream side of the rotation direction regulating mechanism. Therefore, the output of the motor is decelerated in the downstream internal gear on the downstream side of the rotation direction regulating mechanism. Therefore, the rotation direction can be regulated in one direction by the rotation direction regulating mechanism at a stage where the torque of the output is still small. Thereby, the regulation of the rotation direction by the rotation direction regulating mechanism can be made to operate more reliably.

[0023] Next, a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 10. As an example of the power tool 1, a gas spring type driving tool that uses the gas pressure in the accumulator chamber as the thrust for driving the driving tool is exemplified. In the following description, the driving direction of the driving tool is downward, and the reverse driving direction is upward. The user of the power tool 1 is generally located on the left side of the power tool 1 in FIG. 1. The front side of the user is the rear direction, and the back side opposite to the front side is the front direction. The left and right directions are based on the user.

[0024] As shown in Fig. 2, the power tool 1 has a tool body 10 and a main body housing 11 that covers the tool body 10. The main body housing 11 houses a cylinder 12 that extends in the vertical direction. Inside the cylinder 12, a piston 14 is housed so as to be reciprocable vertically. A driver 15 that is long in the vertical direction is connected to the lower surface of the piston 14. The upper end of the cylinder 12 communicates with an accumulator chamber 13. Compressed gas such as air is enclosed in the accumulator chamber 13. The gas pressure in the accumulator chamber 13 acts as a thrust force that biases the upper surface of the piston 14 downward. The right part of the accumulator chamber 13 communicates with an air chamber 13a that extends downward. The air chamber 13a extends downward along the right side surface of the cylinder 12. The air chamber 13a is provided above the lift mechanism 22 so as to overlap with the lift mechanism 22 in the left-right direction.

[0025] As shown in Figs. 1 and 2, a driving nose portion 2 is provided at the lower part of the tool body 10. The driving nose portion 2 has a driver guide 4 that extends generally in the vertical direction. Inside the driver guide 4, a driving passage 2a that extends in the vertical direction is provided. The lower end of the driving passage 2a opens downward as an ejection port 2b. The driving nose portion 2 has a contact arm 3 that abuts against the material W to be driven. The contact arm 3 is movable vertically with respect to the driver guide 4. The contact arm 3 is biased downward by a compression spring 28b provided at the front part of the tool body 10. With the lower end of the contact arm 3 abutting against the material W to be driven, the tool body 10 is further moved closer to the material W to be driven. As a result, the contact arm 3 is pushed by the material W to be driven and moves upward.

[0026] As shown in FIG. 2, the lower part of the driver 15 enters the driving passage 2a. The driver 15 moves downward by the gas pressure in the accumulator chamber 13 acting on the upper surface of the piston 14. The tip 15b of the driver 15 strikes the head of a single driving tool N supplied to the driving passage 2a when it moves to the driving position. The struck driving tool N is ejected from the ejection port 2b and driven into the material W to be driven. A substantially cylindrical cushion 16 for absorbing the impact at the bottom dead center of the piston 14 is provided on the lower side inside the cylinder 12.

[0027] As shown in FIG. 2, a plurality of rack teeth (engaged parts) 15a protruding rightward are provided on the right side of the driver 15. In this embodiment, seven rack teeth 15a are arranged side by side in the vertical direction, which is the longitudinal direction of the driver 15. Each rack tooth 15a is provided in a substantially triangular shape with the bottom facing downward in the driving direction in a front view. The bottom of the rack tooth 15a engages with the engaging part 25 of the lift mechanism 22.

[0028] As shown in FIG. 1, a grip 5 extending rearward and grippable by the user is provided at the rear of the tool body 10. A trigger 6 that the user pulls with a fingertip for operation is provided on the lower surface of the front part of the grip 5. Inside the grip 5, a trigger switch 6a that switches from the off state to the on state in response to the pulling operation of the trigger 6 is provided. When the driving nose part 2 is pressed against the material W to be driven and moves upward to the upper position, the pulling operation of the trigger 6 becomes effective.

[0029] As shown in Fig. 1, a battery mounting portion 7 extending vertically is provided on the rear surface of the grip 5. The battery 8 can be detachably mounted on the battery mounting portion 7. The battery 8 can be repeatedly charged with a charger prepared separately after being removed from the battery mounting portion 7 and then used. The battery 8 can be diverted for use as a power source for other power tools. The battery 8 supplies power to a motor 20 and the like, which will be described later. A controller 9 that mainly controls the drive of the motor 20 is housed in the battery mounting portion 7. The controller 9 is provided with a control board housed in a shallow rectangular box-shaped case. The controller 9 is disposed in front of the battery 8 mounted on the battery mounting portion 7. The controller 9 is disposed in a posture where the longest side extends generally vertically and the shortest side extends generally in the front-rear direction.

[0030] As shown in Fig. 1, the main body housing 11 has a substantially cylindrical mechanism case 11a extending in the front-rear direction below the grip 5. The rear part of the mechanism case 11a is connected to the lower part of the battery mounting portion 7. The grip 5, the battery mounting portion 7, and the mechanism case 11a cooperate to form a loop shape. A motor 20, a planetary gear mechanism 30, and a lift mechanism 22 are housed in the mechanism case 11a in order from the rear to the front. The motor 20, the planetary gear mechanism 30, and the lift mechanism 22 are arranged along the extending direction of the motor axis J extending in the front-rear direction.

[0031] As shown in Fig. 3, the motor 20 has a motor shaft 20a extending in the front-rear direction on the motor axis J. The rear part of the motor shaft 20a is rotatably supported by a bearing 20b. The front part of the motor shaft 20a is rotatably supported by a bearing 20c provided at the rear part of the planetary gear mechanism 30. A fan 21 is attached behind the bearing 20c at the front part of the motor shaft 20a. As the fan 21 rotates integrally with the motor shaft 20a, cooling air flows from the rear to the front in the mechanism case 11a. A drive gear 20d that meshes with the planetary gear mechanism 30 is provided at the front end of the motor shaft 20a.

[0032] As shown in FIGS. 3 and 4, the planetary gear mechanism 30 has three stages of planetary gear trains 31, 32, and 33. The three stages of planetary gear trains 31, 32, and 33 are coaxial with each other and arranged coaxially with the motor axis J. The rotational output of the motor 20 is decelerated by the planetary gear mechanism 30 including the three stages of planetary gear trains 31, 32, and 33 and transmitted to the lift mechanism 22. The planetary gear mechanism 30 has a gear case 34 that houses the three stages of planetary gear trains 31, 32, and 33. The gear case 34 is made of, for example, resin. The gear case 34 is held so as not to move within the mechanism case 11a. A plurality of engaging recesses 34b are provided on the substantially cylindrical inner peripheral surface 34a of the gear case 34. The engaging recesses 34b are recessed radially outward and extend in the front-rear direction from the bottom surface 34c of the gear case 34 to the front end of the gear case 34.

[0033] As shown in FIGS. 3 and 4, the first planetary gear train 31 has three planetary gears 31a, one internal gear 31b, and one carrier 31c. The three planetary gears 31a are meshed with the drive gear 20d of the motor shaft 20a. The drive gear 20d corresponds to the sun gear of the first planetary gear train 31. On the outer peripheral side of the internal gear 31b, a substantially cylindrical gear outer peripheral member 31e having a plurality of convex portions 31f protruding radially outward is provided. The gear outer peripheral member 31e is housed following the inner peripheral surface 34a of the gear case 34. By inserting the plurality of convex portions 31f into the engaging recesses 34b of the gear case 34, the internal gear 31b is prevented from rotating relative to the gear case 34.

[0034] As shown in FIGS. 3 and 4, the three planetary gears 31a are also meshed with the internal gear 31b. The three planetary gears 31a are rotatably supported by the carrier 31c via support shafts 31d, respectively. A washer 31i is interposed behind the three planetary gears 31a and the internal gear 31b.

[0035] As shown in FIGS. 3 and 4, on the outer peripheral side of the carrier 31c, a substantially cylindrical carrier outer peripheral member 31g having a plurality of convex portions 31h protruding radially outward is provided. The carrier outer peripheral member 31g is accommodated following the inner peripheral surface 34a of the gear case 34. By inserting the plurality of convex portions 31h into the engaging concave portions 34b of the gear case 34, the carrier outer peripheral member 31g is prevented from rotating relative to the gear case 34. The planetary gear mechanism 30 has a rotation direction restricting mechanism 40 including the carrier 31c and the carrier outer peripheral member 31g. By the rotation direction restricting mechanism 40, the rotation output is allowed to rotate in the first direction (counterclockwise direction when viewed from the front), and the rotation in the second direction opposite to the first direction is restricted. The rotation direction restricting mechanism 40 will be described in detail later.

[0036] As shown in FIGS. 3 and 4, on the front surface of the carrier 31c of the first planetary gear train 31, the sun gear 32a of the second planetary gear train 32 is integrally formed. The second planetary gear train 32 has four planetary gears 32b, one internal gear 32c, and one carrier 32d. The four planetary gears 32b are meshed with the sun gear 32a. On the outer peripheral side of the internal gear 32c, a substantially cylindrical gear outer peripheral member 32f having a plurality of convex portions 32g protruding radially outward is provided. The gear outer peripheral member 32f is accommodated following the inner peripheral surface 34a of the gear case 34. By inserting the plurality of convex portions 32g into the engaging concave portions 34b of the gear case 34, the internal gear 32c is prevented from rotating relative to the gear case 34.

[0037] As shown in FIGS. 3 and 4, the four planetary gears 32b are also meshed with the internal gear 32c. The four planetary gears 32b are rotatably supported by the carrier 32d via the support shafts 32e, respectively. A washer 32i is interposed behind the four planetary gears 32b and the internal gear 32c. On the outer peripheral side of the carrier 32d, a cylindrical carrier outer peripheral member 32h is provided. The carrier outer peripheral member 32h is accommodated following the inner peripheral surface 34a of the gear case 34. The displacement of the planetary gear trains 32 and 33 in the motor axis J direction is restricted by the carrier outer peripheral member 32h.

[0038] As shown in FIGS. 3 and 4, a sun gear 33a of the third planetary gear train 33 is integrally formed on the front surface of a carrier 32d of the second planetary gear train 32. The third planetary gear train 33 has four planetary gears 33b, one internal gear 33c, and one carrier 33d. The four planetary gears 33b are meshed with the sun gear 33a. On the outer peripheral side of the internal gear 33c, a substantially cylindrical gear outer peripheral member 33g having a plurality of convex portions 33h protruding radially outward is provided. The gear outer peripheral member 33g is accommodated following the inner peripheral surface 34a of the gear case 34. By inserting the plurality of convex portions 33h into the engaging concave portions 34b of the gear case 34, the internal gear 33c is prevented from rotating relative to the gear case 34.

[0039] As shown in FIGS. 3 and 4, the four planetary gears 33b are also meshed with the internal gear 33c. The four planetary gears 33b are rotatably supported by the carrier 33d via support shafts 33e, respectively. A washer 33i is interposed behind the four planetary gears 33b and the internal gear 33c. A spline groove 33f is provided at the center of the carrier 33d. A spline shaft 23a provided at the rear end of the rotating shaft 23 of the lift mechanism 22 is inserted into the spline groove 33f. Thereby, the carrier 33d and the rotating shaft 23 rotate integrally. A bearing 35 for rotatably supporting the carrier 33d and the rotating shaft 23 integrally is provided on the outer peripheral side of the carrier 33d.

[0040] As shown in FIG. 2, the lift mechanism 22 is provided on the right side of the driving nose portion 2. The lift mechanism 22 moves the driver 15 and the piston 14 upward against the air pressure in the accumulator chamber 13. The lift mechanism 22 has a rotating shaft 23 that can rotate around the motor axis J. A wheel 24 is rotatably attached to the rotating shaft 23 around the motor axis J. The wheel 24 is allowed to rotate counterclockwise as viewed from the front and is restricted from rotating clockwise by a rotation direction restricting mechanism 40 (see FIG. 3). A plurality of engaging portions 25 are provided along the outer peripheral edge of the wheel 24. In this embodiment, for example, seven engaging portions 25 are arranged at intervals in the circumferential direction of the wheel 24. For example, a columnar pin extending in the front-rear direction is used for the engaging portion 25. Each engaging portion 25 moves around the motor axis J by the rotation of the wheel 24.

[0041] As shown in FIG. 2, the left part of the wheel 24 enters the driving passage 2a of the driver guide 4 through a window portion 11b provided in the left part of the mechanism case 11a. Each engaging portion 25 of the wheel 24 engages with the bottom of the rack teeth 15a of the driver 15 in the driving passage 2a. With at least one of the engaging portions 25 engaged with the bottom of any of the rack teeth 15a, the wheel 24 rotates counterclockwise as viewed from the front. As a result, the driver 15 and the piston 14 move upward. The gas pressure in the accumulator chamber 13 is increased by the upward movement of the piston 14.

[0042] As shown in FIG. 2, a dial-type adjuster 28 is provided at the left front part of the driving nose portion 2. The adjuster 28 has a rotating shaft 28a extending in the vertical direction. The rotating shaft 28a can rotate integrally with the adjuster 28 and can move in the vertical direction. An adjuster connecting portion 3a connected to the adjuster 28 is provided at the upper part of the contact arm 3. The contact arm 3 can move in the vertical direction integrally with the adjuster 28. By rotating the adjuster 28 around its axis, the vertical position of the contact arm 3 can be adjusted. The adjuster 28 has a compression spring 28b disposed on the outer peripheral side of the rotating shaft 28a and supported by the main body housing 11. The compression spring 28b biases the adjuster 28 and the contact arm 3 downward.

[0043] As shown in FIG. 2, a switch 29 is provided above the adjuster 28. When the contact arm 3 moves upward, the adjuster 28 presses a protruding pin 29a of the switch 29 via a spring (not shown). As a result, the switch 29 is turned on and transmits an on-signal to the controller 9. When an on-signal is transmitted to the controller 9, the pulling operation of the trigger 6 becomes effective (see FIG. 1). When the contact arm 3 is biased downward, the protruding pin 29a of the switch 29 is not pressed. Therefore, the switch 29 does not transmit an on-signal, and the pulling operation of the trigger is not effective.

[0044] As shown in FIG. 1, a substantially rectangular box-shaped magazine 26 is provided behind the driving nose portion 2. The magazine 26 extends straight backward from the driver guide 4 and is provided in a substantially rectangular box shape. A plurality of driving tools N (see FIG. 2) extending in the vertical direction and arranged in parallel in the front-rear direction are loaded in the magazine 26. Inside the magazine 26, a pusher 27 for supplying the driving tool N to the driving passage 2a is provided. The pusher 27 is biased forward by a spring (not shown). The front surface of the pusher 27 pushes the driving tool N accommodated in the front toward the driving passage 2a. As a result, the driving tools N are supplied one by one forward from the magazine 26 toward the driving passage 2a.

[0045] As shown in FIGS. 3, 5, and 6, the rotation direction restricting mechanism 40 has a substantially cylindrical outer ring 41 and a substantially disc-shaped inner peripheral member 42 provided inside the outer ring 41. In each embodiment of the present disclosure, the outer ring 41 is a carrier outer peripheral member 31g of the first planetary gear train 31. In each embodiment of the present disclosure, the inner peripheral member 42 is a carrier 31c of the first planetary gear train 31. The inner peripheral member 42 is accommodated inside the outer ring 41. The inner peripheral surface 41b of the outer ring 41 and the outer peripheral surface 42a of the inner peripheral member 42 face each other in the radial direction.

[0046] As shown in FIGS. 3 and 6, the outer peripheral surface 41a of the outer ring 41 and the inner peripheral surface 34a of the gear case 34 face each other in the radial direction. The inner diameter of the inner peripheral surface 34a of the gear case 34 excluding the engagement recess 34b is substantially the same length as the outer diameter D1 of the internal gear 31b (see FIG. 9). The outer diameter D2 of the outer peripheral surface 41a of the outer ring 41 excluding the convex portion 31h is slightly shorter than the outer diameter D1. Therefore, a slight gap is provided between the outer peripheral surface 41a of the outer ring 41 and the inner peripheral surface 34a of the gear case 34.

[0047] As shown in FIGS. 5 and 6, the rotation direction restricting mechanism 40 has a plurality of cam surfaces 43. The plurality of cam surfaces 43 are recessed radially inward from the outer peripheral surface 42a of the inner peripheral member 42. The plurality of cam surfaces 43 are provided at substantially equal intervals in the circumferential direction of the outer peripheral surface 42a. For example, six cam surfaces 43 are provided on the outer peripheral surface 42a at 60° intervals in the circumferential direction. One lock member 44 is inserted into each cam surface 43. The lock member 44 is, for example, a columnar pin having substantially the same length as the thickness of the inner peripheral member 42 before and after. A washer 31j is interposed behind the inner peripheral member 42 and the lock member 44. The washer 31j is provided with three holes 31k for inserting three support shafts 31d extending rearward from the inner peripheral member 42.

[0048] As shown in FIGS. 5 to 7, each cam surface 43 is provided asymmetrically in the circumferential direction of the inner peripheral member 42. The cam surface 43 on the first direction R1 (counterclockwise direction when viewed from the front) side of the outer peripheral surface 42a is provided as a narrow-width portion 43b having a narrow radial width. The cam surface 43 on the second direction R2 (clockwise direction when viewed from the front) side of the outer peripheral surface 42a is provided as a wide-width portion 43a having a wide radial width. The radial width of the wide-width portion 43a is larger than the diameter of the lock member 44. The radial width of the narrow-width portion 43b is smaller than the diameter of the lock member 44.

[0049] As shown in FIGS. 3, 6, and 9, the rotation direction restricting mechanism 40 has an eccentric mechanism 45 that eccentrically positions the outer ring 41 and the inner peripheral member 42 relative to each other. In the present embodiment, the eccentric mechanism 45 is one protrusion 45 that projects radially inward from the inner peripheral surface 34a of the gear case 34. The length from the tip of the protrusion 45 to the opposing inner peripheral surface 34a of the gear case 34 is substantially the same as the outer diameter D2 of the outer ring 41. The outer ring 41 is eccentric with respect to the gear case 34 and the inner peripheral member 42 in the protruding direction of the protrusion 45. Therefore, the center 41c of the inner peripheral surface of the outer ring 41 is displaced in the protruding direction of the protrusion 45 with respect to the motor axis J, which is the rotation center 42b of the inner peripheral member 42.

[0050] As shown in FIGS. 3 and 10, the protrusion 45 is provided in a substantially rectangular shape in side view. The protrusion 45 is provided only at a position that is horizontally aligned with the outer ring 41 in the radial direction, and is not provided, for example, on the inner peripheral surface 34a of the gear case 34 in front of or behind the outer ring 41. Each component of the planetary gear mechanism 30 is assembled to the gear case 34 in order from the bottom surface 34c side of the rear end. The upstream planetary gear 31a and the upstream internal gear 31b, which are located upstream of the outer ring 41 in terms of power transmission, are assembled to the gear case 34 prior to the outer ring 41. The gear case 34 is made of a resin that is easily elastically deformed, and the protruding length of the protrusion 45 is small. Therefore, the upstream internal gear 31b can be assembled beyond the protrusion 45. The upstream internal gear 31b assembled to the gear case 34 is held at a rear position where it does not interfere with the protrusion 45.

[0051] As shown in FIG. 3, the downstream planetary gear 32b and the downstream internal gear 32c, which are located downstream of the outer ring 41 in terms of power transmission, are assembled to the gear case 34 after the outer ring 41. The downstream internal gear 32c assembled to the gear case 34 is held at a front position where it does not interfere with the protrusion 45.

[0052] As shown in FIGS. 6 to 8, by eccentrically displacing the outer ring 41 and the inner peripheral member 42 relative to each other, the radial distance between the cam surface 43 and the inner peripheral surface 41b of the outer ring 41 becomes different for each cam surface 43. Specifically, the cam surface 43 on the side where the protrusion 45 is provided (the left side in the figure) has a smaller radial distance from the inner peripheral surface 41b of the outer ring 41. The cam surface 43 on the side facing the protrusion 45 (the right side in the figure) has a larger radial distance from the inner peripheral surface 41b of the outer ring 41.

[0053] As shown in FIG. 6, when the inner peripheral member 42 rotates in the first direction R1, all the lock members 44 move toward the widened portion 43a within all the cam surfaces 43. Therefore, all the lock members 44 have a gap with the inner peripheral surface 41b of the outer ring 41. Therefore, the lock members 44 do not prevent the inner peripheral member 42 from rotating in the first direction R1. Thereby, the rotation of the inner peripheral member 42 in the first direction R1 is allowed.

[0054] As shown in FIGS. 7 and 8, when the inner peripheral member 42 attempts to rotate in the second direction R2, the lock members 44 move toward the narrow portion 43b within the cam surfaces 43. Particularly, in the cam surface 43 located on the side where the protrusion 45 protrudes (the left side in the figure), the lock member 44 engages between the cam surface 43 and the inner peripheral surface 41b of the outer ring 41. For example, if there are three or more lock members 44 that engage between the cam surface 43 and the inner peripheral surface 41b of the outer ring 41, the rotation of the inner peripheral member 42 is restricted. More specifically, the rotation center 42b of the inner peripheral member 42 is positioned inside the triangle formed by the three lock members 44 that engage with the three cam surfaces 43, thereby restricting the rotation of the inner peripheral member 42 in the second direction R2. Thus, by eccentrically displacing the outer ring 41 and the inner peripheral member 42 relative to each other, the number of lock members 44 that reliably engage between the cam surface 43 and the inner peripheral surface 41b of the outer ring 41 can be increased. Thereby, the rotation of the inner peripheral member 42 in the second direction R2 can be more reliably restricted.

[0055] Next, a series of steps of the driving operation of the power tool 1 will be described with reference to Figures 1 to 3. The driver 15 in the standby position is stopped slightly below the top dead center. When the driver 15 is in the standby position, the bottom surface of the rack tooth 15a at the lowest end and the final engagement part 25a of the lift mechanism 22 are engaged. When the contact arm 3 is pressed against the workpiece W to be driven, it moves upward. The adjuster 28 moves upward in conjunction with the contact arm 3 and presses the protruding pin 29a of the switch 29. The switch 29 transmits an ON signal to the controller 9. When the controller 9 receives the ON signal from the switch 29 and the trigger 6 is pulled, it starts the motor 20. When the motor 20 is started, the wheel 24 of the lift mechanism 22 rotates. The final engagement part 25a moves the rack tooth 15a at the lowest end upward. This causes the driver 15 to move upward from the standby position to the top dead center.

[0056] When the driver 15 is stopped at the standby position, the tip 15b of the driver 15 and the head of the foremost driving tool N overlap in the front-rear direction. Therefore, the driving tool N has not yet been loaded into the driving passage 2a. When the tip 15b of the driver 15 moves above the head of the foremost driving tool N, the foremost driving tool N is loaded into the driving passage. When the driver 15 moves up to the top dead center and reaches a state immediately before driving, the final engagement part 25a is released from the bottom of the lowest rack tooth 15a by the rotation of the wheel 24. The driver 15 is forced downward by the gas pressure of the pressure accumulator 13 applied to the piston 14. The tip 15b of the driver 15 moves downward and strikes the driving tool N in the driving passage 2a. The struck driving tool N is injected into the material W to be driven through the injection port 2b. When the driver 15 moves downward, all of the engagement parts 25 move to the right of the driving path 2a. This prevents interference between the rack teeth 15a of the driver 15 moving downward and the engagement parts 25, ensuring a smooth driving operation.

[0057] The wheel 24 continues to rotate even while the driver 15 is moving downward and after reaching the bottom dead center. When the driver 15 is at the bottom dead center and the wheel 24 rotates by a predetermined rotation angle, one of the engaging portions 25 engages with the bottom of the uppermost rack tooth 15a. This starts the return operation of moving the driver 15 upward. When the final engaging portion 25a engages with the bottom of the lowermost rack tooth 15a, the driver 15 returns to the standby position. For example, by appropriately measuring the time from the start of activation of the motor 20 or by appropriately measuring the rotational position of the wheel 24, the motor 20 is stopped when the piston 14 reaches the standby position. Thereby, the driver 15 is held at the standby position. Thus, a series of driving operations is completed.

[0058] As described above, the power tool 1 has a motor 20 (see FIG. 3) as shown in FIGS. 6 to 8. The power tool 1 has a rotation direction regulating mechanism 40 that regulates the rotation direction of the rotation caused by the output of the motor 20. The rotation direction regulating mechanism 40 has an outer ring 41. The rotation direction regulating mechanism 40 has an inner peripheral member 42 provided on the inner peripheral side of the outer ring 41. The rotation direction regulating mechanism 40 has a plurality of cam surfaces 43 recessed in the outer peripheral surface 42a of the inner peripheral member 42. The rotation direction regulating mechanism 40 has a lock member 44 that is movably disposed within the cam surface 43 and permits relative rotation of the outer ring 41 and the inner peripheral member 42 in a first direction R1 and restricts relative rotation in a second direction R2. The rotation direction regulating mechanism 40 has a projection (eccentric mechanism) 45 that eccentrically positions the outer ring 41 and the inner peripheral member 42 relative to each other.

[0059] Therefore, by eccentrically positioning the outer ring 41 and the inner peripheral member 42 relative to each other by the projection 45, a part of the plurality of cam surfaces 43 is disposed at a location where the outer ring 41 and the inner peripheral member 42 are in close contact in the radial direction. Therefore, at least a part of the lock member 44 inserted into the cam surface 43 can be in close contact with both the outer ring 41 and the inner peripheral member 42. Therefore, when the outer ring 41 and the inner peripheral member 42 attempt to rotate relative to each other in the second direction R2, the lock member 44 is surely pinched between the outer ring 41 and the inner peripheral member 42. Thereby, the relative rotation direction of the outer ring 41 and the inner peripheral member 42 can be more surely regulated in one direction.

[0060] As shown in FIGS. 3 and 6 to 8, the power tool 1 has a gear case (holding member) 34 that surrounds the outer ring 41. On one of the outer ring 41 and the gear case 34, a projection 45 of an eccentric mechanism that protrudes toward the other and abuts against the other is provided. Therefore, the outer ring 41 and the inner peripheral member 42 can be eccentric to each other with a simple structure in which the projection 45 is provided on the outer ring 41 or the gear case 34. For this reason, the rotation direction restricting mechanism 40 can be provided without significantly changing from the conventional structure, and the rotation direction can be more reliably restricted to one direction.

[0061] As shown in FIGS. 5 to 8, a cam surface 43 is provided on the inner peripheral member 42. Therefore, when the inner peripheral member 42 rotates, the lock member 44 can be smoothly moved along the cam surface 43 by using centrifugal force. Thereby, the allowance of rotation in the first direction R1 and the restriction of rotation in the second direction R2 can be made to operate more reliably.

[0062] As shown in FIGS. 3 and 6 to 8, the power tool 1 has a gear case (holding member) 34 that surrounds the outer ring 41 and restricts the rotation of the outer ring 41. The inner peripheral member 42 is rotatable by the motor 20. Therefore, the outer ring 41 is provided so as not to rotate integrally with the gear case 34, and the inner peripheral member 42 is provided as a component that rotates by the output of the motor 20. Thereby, for example, the rotation direction restricting mechanism 40 can be provided in a gear train or the like that transmits while converting the output of the motor 20.

[0063] As shown in FIG. 3, the power tool 1 has a planetary gear mechanism 30 that decelerates the rotation by the output of the motor 20. The planetary gear mechanism 30 has a planetary gear 31a that is rotatably held by the inner peripheral member 42. Therefore, the rotation direction restricting mechanism 40 that can more reliably restrict the rotation direction to one direction can be provided in the planetary gear mechanism 30 that has a large number of parts and little space.

[0064] As shown in FIGS. 3, 4, and 9, the planetary gear mechanism 30 has an internal gear 31b that engages with a planetary gear 31a. The internal gear 31b and the outer ring 41 are arranged side by side and housed in the gear case 34. The outer diameter D2 of the outer ring 41 is smaller than the outer diameter D1 of the internal gear 31b. Therefore, by making the outer diameter D2 of the outer ring 41 smaller than the outer diameter D1 of the internal gear 31b, a gap can be provided between the outer diameter D2 of the outer ring 41 and the inner peripheral surface 34a of the gear case 34. The center of the internal gear 31b is located at the center of the gear case 34. Therefore, the outer ring 41 can be eccentric with respect to the center of the internal gear 31b by utilizing the gap.

[0065] As shown in FIG. 3, the power tool 1 has a planetary gear mechanism 30 that decelerates the rotation by the output of the motor 20. The planetary gear mechanism 30 has an upstream internal gear 31b. The planetary gear mechanism 30 has an upstream planetary gear 31a that engages with the upstream internal gear 31b. The planetary gear mechanism 30 has a downstream internal gear 32c. The planetary gear mechanism 30 has a downstream planetary gear 32b that engages with the downstream internal gear 32c. The upstream internal gear 31b, the outer ring 41, and the downstream internal gear 32c are housed in the gear case 34 in this order. The gear case 34 is provided with a projection 45 of an eccentric mechanism that projects toward the outer ring 41 and abuts against the outer ring 41. The projection 45 makes a part of the inner diameter of the gear case 34 smaller than the outer diameter D1 of the upstream internal gear 31b and the outer diameter D1 of the downstream internal gear 32c (see FIG. 9).

[0066] Therefore, the outer ring 41 can be assembled together with the components of the planetary gear mechanism 30 into the gear case 34. Moreover, the projection 45 of the gear case 34 is provided so as not to interfere with members other than the outer ring 41, such as the upstream internal gear 31b and the downstream internal gear 32c. Thus, only the outer ring 41 can be eccentric with respect to the motor axis J, which is the rotation center 42b of the inner peripheral member 42, without disturbing the drive of the planetary gear mechanism 30.

[0067] As shown in FIGS. 2 and 3, the power tool 1 has a lift mechanism 22 that accumulates energy by the output of the motor 20. The power tool 1 has a driver 15 that moves in the driving direction by the energy accumulated in the lift mechanism 22 to drive the driving tool N. Therefore, the lift mechanism 22 accumulates energy by rotating forward. If the lift mechanism 22 reverses due to the accumulated energy, the accumulated energy will be lost and a normal driving operation cannot be performed. By allowing the rotation direction of the lift mechanism 22 to be only in the forward rotation direction with the rotation direction regulating mechanism 40, it is possible to prevent the accumulated energy from being inadvertently lost.

[0068] As shown in FIG. 3, the power tool 1 has a planetary gear mechanism 30 that decelerates the rotation by the output of the motor 20. The planetary gear mechanism 30 has an upstream internal gear 31b. The planetary gear mechanism 30 has an upstream planetary gear 31a that engages with the upstream internal gear 31b. The planetary gear mechanism 30 has a downstream internal gear 32c. The planetary gear mechanism 30 has a downstream planetary gear 32b that engages with the downstream internal gear 32c. The downstream internal gear 32c is provided on the downstream side of the rotation direction regulating mechanism 40. Therefore, the output of the motor 20 is decelerated in the downstream internal gear 32c on the downstream side of the rotation direction regulating mechanism 40. Therefore, the rotation direction can be regulated in one direction by the rotation direction regulating mechanism 40 at a stage where the torque of the output is still small. Thereby, the regulation of the rotation direction by the rotation direction regulating mechanism 40 can be made to operate more reliably.

[0069] Next, a second embodiment of the present disclosure will be described with reference to FIG. 11. The power tool 50 of the second embodiment has a rotation direction restricting mechanism 51 instead of the rotation direction restricting mechanism 40 shown in FIG. 6. In the following description, only the parts different from the first embodiment will be described in detail. The rotation direction restricting mechanism 51 has a carrier outer peripheral member 31g as an outer ring 52. The rotation direction restricting mechanism 51 has a carrier 31c as an inner peripheral member 53. A plurality of cam surfaces 54 are provided on the outer peripheral surface 53a of the inner peripheral member 53. One lock member 55 is inserted into each cam surface 54. The inner peripheral member 53, the outer peripheral surface 53a, and the rotation center 53b are provided in the same manner as the inner peripheral member 42, the outer peripheral surface 42a, and the rotation center 42b shown in FIG. 6. The cam surface 54, the widened portion 54a, the narrowed portion 54b, and the lock member 55 are provided in the same manner as the cam surface 43, the widened portion 43a, the narrowed portion 43b, and the lock member 44 shown in FIG. 6.

[0070] As shown in FIG. 11, the outer peripheral surface 52a and the inner peripheral surface 52b of the outer ring 52 are eccentric to each other. The center 52d of the inner peripheral surface of the inner peripheral surface 52b is shifted to the right in the figure with respect to the center 52c of the outer peripheral surface of the outer peripheral surface 52a. The rotation center 53b of the inner peripheral member 53 is at the same position as the center 52c of the outer peripheral surface of the outer peripheral surface 52a. Therefore, the inner peripheral surface 52b of the outer ring 52 is eccentric with respect to the rotation center 53b of the inner peripheral member 53. Therefore, the cam surface 54 on the left side in the figure has a smaller radial distance from the inner peripheral surface 52b of the outer ring 52. The cam surface 54 on the right side in the figure has a larger radial distance from the inner peripheral surface 52b of the outer ring 52. Thus, the rotation direction restricting mechanism 51 operates in the same manner as the rotation direction restricting mechanism 40 shown in FIGS. 6 to 8.

[0071] As shown in Fig. 11, when the inner peripheral member 53 rotates in the first direction R1, all the lock members 55 move toward the widened portion 54a within all the cam surfaces 54. Therefore, all the lock members 55 have a gap with the inner peripheral surface 52b of the outer ring 52. Thereby, the lock members 55 do not prevent the rotation of the inner peripheral member 53 in the first direction R1. When the inner peripheral member 53 attempts to rotate in the second direction R2, the lock members 55 move toward the narrow portion 54b within the cam surfaces 54. For example, in at least three cam surfaces 54, the lock members 55 engage between the cam surfaces 54 and the inner peripheral surface 52b of the outer ring 52. Thereby, the rotation of the inner peripheral member 53 in the second direction R2 can be more reliably restricted.

[0072] As described above, as shown in Fig. 11, the inner peripheral member 53 is rotatable by a motor 20 (see Fig. 3). The outer ring 52 has an inner peripheral surface 52b that is eccentric with respect to the rotation center 53b of the inner peripheral member 53. Therefore, for example, when the inner peripheral member 53 rotates, the inner peripheral surface 52b of the outer ring 52 and the outer peripheral surface 53a of the inner peripheral member 53 can be mutually eccentric while giving the inner peripheral member 53 axial symmetry. Therefore, the wobbling of the inner peripheral member 53 can be suppressed, and the rotation direction can be more reliably restricted to one direction.

[0073] Next, a third embodiment of the present disclosure will be described with reference to Fig. 12. The power tool 60 of the third embodiment has a rotation direction restricting mechanism 61 instead of the rotation direction restricting mechanism 40 shown in Fig. 6. In the following description, only the parts different from the first embodiment will be described in detail. The rotation direction restricting mechanism 61 has a carrier outer peripheral member 31g as an outer ring 62. The rotation direction restricting mechanism 61 has a carrier 31c as an inner peripheral member 63. A plurality of cam surfaces 64 are provided on the outer peripheral surface 63a of the inner peripheral member 63. One lock member 65 is inserted into each cam surface 64. The outer ring 62, the outer peripheral surface 62a, and the inner peripheral surface 62b are provided in the same manner as the outer ring 41, the outer peripheral surface 41a, and the inner peripheral surface 41b shown in Fig. 6. The cam surfaces 64, the widened portions 64a, the narrow portions 64b, and the lock members 65 are provided in the same manner as the cam surfaces 43, the widened portions 43a, the narrow portions 43b, and the lock members 44 shown in Fig. 6.

[0074] As shown in Fig. 12, the outer peripheral surface 63a of the inner peripheral member 63 is eccentric with respect to the rotation center 63b. The eccentric center 63c of the outer peripheral surface 63a is shifted to the left in the figure with respect to the rotation center 63b. The inner peripheral surface 62b of the outer ring 62 is arranged around the rotation center 63b of the inner peripheral member 63. Therefore, the cam surface 64 on the left side in the figure has a smaller radial distance from the inner peripheral surface 62b of the outer ring 62. The cam surface 64 on the right side in the figure has a larger radial distance from the inner peripheral surface 62b of the outer ring 62. Thus, the rotation direction regulating mechanism 61 operates in the same manner as the rotation direction regulating mechanism 40 shown in Figs. 6 to 8.

[0075] As shown in Fig. 12, when the inner peripheral member 63 rotates in the first direction R1, the locking members 65 move toward the widened portion 64a within all the cam surfaces 64. Therefore, all the locking members 65 have a gap with the inner peripheral surface 62b of the outer ring 62. Thus, the locking members 65 do not prevent the rotation of the inner peripheral member 63 in the first direction R1. When the inner peripheral member 63 attempts to rotate in the second direction R2, the locking members 65 move toward the narrow portion 64b within the cam surfaces 64. For example, in at least three cam surfaces 64, the locking members 65 engage between the cam surface 64 and the inner peripheral surface 62b of the outer ring 62. Thereby, the rotation of the inner peripheral member 63 in the second direction R2 can be more reliably regulated.

[0076] As described above, as shown in Fig. 12, the inner peripheral member 63 can be rotated by the motor 20 (see Fig. 3). The inner peripheral member 63 has an outer peripheral surface 63a that is eccentric with respect to the rotation center 63b of the inner peripheral member 63. Therefore, the outer ring 62 can be assembled in the same manner as the conventional structure, and the inner peripheral surface 62b of the outer ring 62 and the outer peripheral surface 63a of the inner peripheral member 63 can be mutually eccentric to more reliably regulate the rotation direction in one direction.

[0077] Next, a fourth embodiment of the present disclosure will be described with reference to FIG. 13. The power tool 70 of the fourth embodiment has a rotation direction restricting mechanism 71 instead of the rotation direction restricting mechanism 40 shown in FIG. 6. In the following description, only the parts different from the first embodiment will be described in detail. The rotation direction restricting mechanism 71 has a carrier outer peripheral member 31g as an outer ring 72. The rotation direction restricting mechanism 71 has a carrier 31c as an inner peripheral member 73. One protrusion (eccentric mechanism) 76 protruding radially inward is provided on the inner peripheral surface 34a of the gear case 34. The protrusion 76 is provided in the same manner as the protrusion 45 shown in FIG. 6. The rotation direction restricting mechanism 71 has a lock member 75 provided in the same manner as the lock member 44 (see FIG. 6).

[0078] As shown in FIG. 13, the inner peripheral member 73 is not provided with a cam surface and is provided in a disc shape. The outer peripheral surface 73a of the inner peripheral member 73 is provided as an arc surface centered on the rotation center 73b. The outer peripheral surface 72a and the inner peripheral surface 72b of the outer ring 72 extend in an arc shape centered on the inner peripheral surface center 72c. A plurality of cam surfaces 74 are provided on the inner peripheral surface 72b of the outer ring 72. The cam surfaces 74 are recessed radially outward. The plurality of cam surfaces 74 are provided at substantially equal intervals in the circumferential direction of the inner peripheral surface 72b. For example, six cam surfaces 74 are provided on the inner peripheral surface 72b at intervals of 60° in the circumferential direction. One lock member 75 is inserted into each cam surface 74.

[0079] As shown in FIG. 13, each cam surface 74 is provided asymmetrically in the circumferential direction of the outer ring 72. The cam surface 74 on the first direction R1 (counterclockwise direction when viewed from the front) side of the inner peripheral surface 72b is provided as a widened portion 74a having a wide radial width. The cam surface 74 on the second direction R2 (clockwise direction when viewed from the front) side of the inner peripheral surface 72b is provided as a narrow portion 74b having a narrow radial width. The radial width of the widened portion 74a is larger than the diameter of the lock member 75. The radial width of the narrow portion 74b is smaller than the diameter of the lock member 75.

[0080] As shown in Fig. 13, the inner peripheral surface 72b of the outer ring 72 is eccentric with respect to the outer peripheral surface 73a of the inner peripheral member 73 by the projection 76. The center 72c of the inner peripheral surface of the outer ring 72 is shifted to the right in the figure with respect to the rotation center 73b of the inner peripheral member 73. Therefore, the cam surface 74 on the left side in the figure has a smaller radial distance from the outer peripheral surface 73a of the inner peripheral member 73. The cam surface 74 on the right side in the figure has a larger radial distance from the outer peripheral surface 73a of the inner peripheral member 73. Thus, the rotation direction regulating mechanism 71 operates in the same manner as the rotation direction regulating mechanism 40 shown in Figs. 6 to 8.

[0081] As shown in Fig. 13, when the inner peripheral member 73 rotates in the first direction R1, all the lock members 75 move toward the widened portion 74a within all the cam surfaces 74. Therefore, all the lock members 75 have a gap with the outer peripheral surface 73a of the inner peripheral member 73. Thus, the lock members 75 do not prevent the rotation of the inner peripheral member 73 in the first direction R1. When the inner peripheral member 73 attempts to rotate in the second direction R2, the lock members 75 move toward the narrow portion 74b within the cam surfaces 74. For example, in at least three cam surfaces 74, the lock members 75 engage between the cam surface 74 and the outer peripheral surface 73a of the inner peripheral member 73. Thereby, the rotation of the inner peripheral member 73 in the second direction R2 can be more reliably regulated.

[0082] As described above, the power tool 70 has a motor 20 (see Fig. 3) as shown in Fig. 13. The power tool 70 has a rotation direction regulating mechanism 71 that regulates the rotation direction of the rotation by the output of the motor 20. The rotation direction regulating mechanism 71 has an outer ring 72. The rotation direction regulating mechanism 71 has an inner peripheral member 73 provided on the inner peripheral side of the outer ring 72. The rotation direction regulating mechanism 71 has a cam surface 74 recessed in the inner peripheral surface 72b of the outer ring 72. The rotation direction regulating mechanism 71 has a lock member 75 that is movably disposed within the cam surface 74 and permits the relative rotation in the first direction R1 between the outer ring 72 and the inner peripheral member 73 and regulates the relative rotation in the second direction R2. The rotation direction regulating mechanism 71 has a projection (eccentric mechanism) 76 that eccentrically positions the outer ring 72 and the inner peripheral member 73 with respect to each other.

[0083] Therefore, by eccentrically displacing the outer ring 72 and the inner peripheral member 73 relative to each other by the protrusion 76, a part of the plurality of cam surfaces 74 is disposed at a location where the outer ring 72 and the inner peripheral member 73 are in close contact in the radial direction. Therefore, at least a part of the lock member 75 inserted into the cam surface 74 can be in close contact with both the outer ring 72 and the inner peripheral member 73. Therefore, when the outer ring 72 and the inner peripheral member 73 attempt to rotate relative to each other in the second direction R2, the lock member 75 is surely pinched between the outer ring 72 and the inner peripheral member 73. Thereby, the relative rotational direction of the outer ring 72 and the inner peripheral member 73 can be more surely restricted to one direction.

[0084] Various modifications can be made to the power tools 1, 50, 60, and 70 of each of the embodiments described above. A gas spring type driving tool has been exemplified as the power tool. Instead of this, for example, the present disclosure may be applied to a power tool having a power transmission path in which the rotational direction is to be restricted to one direction, such as a ratchet, a screwdriver, a caulking gun, a reciprocating saw, or the like.

[0085] The number of cam surfaces and lock members is not limited to those exemplified and may be changed as appropriate. A configuration in which a rotation direction restricting mechanism is provided in the planetary gear mechanism 30 has been exemplified. Instead of this, for example, a rotation direction restricting mechanism may be provided in a reduction gear train having no planetary gear train. A configuration in which a rotation direction restricting mechanism is provided in the planetary gear mechanism 30 having a three-stage planetary gear train has been exemplified. Instead of this, for example, a rotation direction restricting mechanism may be provided in a planetary gear mechanism having a two-stage or four-stage or more planetary gear train.

[0086] A configuration in which a rotation direction restricting mechanism is provided in the carrier 31c of the first planetary gear train 31 and the carrier outer peripheral member 31g has been exemplified. Instead of this, for example, a rotation direction restricting mechanism may be provided in the carrier 32d of the second planetary gear train 32 and the carrier outer peripheral member 31g. Since there is a third planetary gear train 33 on the downstream side of the second planetary gear train 32, the torque is not increased to the maximum in the second planetary gear train 32. Therefore, the load applied to the rotation direction restricting mechanism when restricting the rotation in the second direction R2 is not sufficiently large. Therefore, the effect of restricting the rotation direction is sufficient.

[0087] An example of a configuration is illustrated in which the inner peripheral member rotates about the axis and the outer ring is held so as not to rotate with respect to the gear case 34. Alternatively, for example, a configuration may be adopted in which the outer ring is rotatable about the axis and the inner peripheral member is held so as not to rotate. Or, a configuration may be adopted in which both the inner peripheral member and the outer ring are rotatable about the axis and the relative rotational positions of the two change.

Explanation of Signs

[0088] 1…Power tool 2…Driving nose portion, 2a…Driving passage, 2b…Outlet 3…Contact arm, 3a…Adjuster connecting portion 4…Driver guide 5…Grip 6…Trigger, 6a…Trigger switch 7…Battery mounting portion 8…Battery 9…Controller 10…Tool body 11…Main body housing, 11a…Mechanism case, 11b…Window portion 12…Cylinder 13…Accumulator chamber, 13a…Air chamber 14…Piston 15…Driver, 15a…Rack teeth (engaged portion), 15b…Tip 16…Cushion 20…Motor, 20a…Motor shaft, 20b, 20c…Bearings, 20d…Drive gear 21…Fan 22…Lift mechanism 23…Rotating shaft, 23a…Splined shaft 24…Wheel 25…Engaging portion, 25a…Final engaging portion 26…Magazine 27…Pusher 28…Adjuster, 28a…Rotating shaft, 28b…Compression spring 29…Switch, 29a…Protruding pin, 29b…Spring 30…Planetary gear mechanism 31…First planetary gear train, 31a…(Upstream side) planetary gear 31b… (upstream side) internal gear, 31c… carrier (inner peripheral member), 31d… support shaft 31e… gear outer peripheral member, 31f… convex portion, 31g… carrier outer peripheral member (outer ring) 31h… convex portion, 31i… washer, 31j… washer, 31k… hole 32… second planetary gear train, 32a… sun gear, 32b… (downstream side) planetary gear 32c… (downstream side) internal gear, 32d… carrier, 32e… support shaft 32f… gear outer peripheral member, 32g… convex portion, 32h… carrier outer peripheral member 32i… washer 33… third planetary gear train, 33a… sun gear, 33b… planetary gear 33c… internal gear, 33d… carrier, 33e… support shaft, 33f… spline groove 33g… gear outer peripheral member, 33h… convex portion, 33i… washer 34… gear case (holding member), 34a… inner peripheral surface, 34b… engaging concave portion, 34c… bottom surface 35… bearing 40… rotation direction restricting mechanism 41… outer ring, 41a… outer peripheral surface, 41b… inner peripheral surface, 41c… center of inner peripheral surface 42… inner peripheral member, 42a… outer peripheral surface, 42b… rotation center 43… cam surface, 43a… widened portion, 43b… narrow portion 44… locking member 45… protrusion (eccentric mechanism) 50… power tool 51… rotation direction restricting mechanism 52… outer ring, 52a… outer peripheral surface, 52b… inner peripheral surface, 52c… center of outer peripheral surface 52d… center of inner peripheral surface 53… inner peripheral member, 53a… outer peripheral surface, 53b… rotation center 54… cam surface, 54a… widened portion, 54b… narrow portion 55… locking member 60… power tool 61… rotation direction restricting mechanism 62… outer ring, 62a… outer peripheral surface, 62b… inner peripheral surface 63… inner peripheral member, 63a… outer peripheral surface, 63b… rotation center, 63c… eccentric center 64…Cam surface, 64a…Widthening portion, 64b…Narrow-width portion 65…Locking member 70…Power tool 71…Rotation direction restricting mechanism 72…Outer ring, 72a…Outer peripheral surface, 72b…Inner peripheral surface, 72c…Center of inner peripheral surface 73…Inner peripheral member, 73a…Outer peripheral surface, 73b…Rotation center 74…Cam surface, 74a…Widthening portion, 74b…Narrow-width portion 75…Locking member 76…Projection (eccentric mechanism) N…Driver W…Workpiece to be driven J…Motor axis R1…First direction, R2…Second direction D1…Outer diameter (of internal gear), D2…Outer diameter (of outer ring)

Claims

1. An electric tool, comprising a motor, and having a rotation direction regulating mechanism for regulating the rotation direction of a rotation direction rotated by the output of the motor, the rotation direction regulating mechanism comprising: an outer ring, an inner peripheral member provided on the inner peripheral side of the outer ring, a plurality of cam surfaces recessed in the inner peripheral surface of the outer ring or the outer peripheral surface of the inner peripheral member, a lock member movably disposed within the cam surface, allowing relative rotation of the outer ring and the inner peripheral member in a first direction and restricting relative rotation in a second direction, and an electric tool having an eccentric mechanism for eccentrically displacing the outer ring and the inner peripheral member relative to each other.

2. The electric tool according to claim 1, having a holding member surrounding the outer ring, and a projection of the eccentric mechanism protruding from one of the outer ring and the holding member and abutting against the other.

3. The electric tool according to claim 1, wherein the inner peripheral member is rotatable by the motor, and the outer ring has the inner peripheral surface eccentric with respect to the rotation center of the inner peripheral member.

4. The electric tool according to claim 1, wherein the inner peripheral member is rotatable by the motor, and the inner peripheral member has an outer peripheral surface eccentric with respect to the rotation center of the inner peripheral member.

5. The electric tool according to any one of claims 1 to 4, wherein the cam surface is provided on the inner peripheral member.

6. The electric tool according to any one of claims 1 to 5, having a holding member surrounding the outer ring and restricting the rotation of the outer ring, The inner peripheral member is a power tool that can be rotated by the motor.

7. A power tool according to any one of claims 1 to 6, having a planetary gear mechanism that decelerates the rotation by the output of the motor, The planetary gear mechanism is a power tool having a planetary gear rotatably held by the inner peripheral member.

8. A power tool according to claim 7, The planetary gear mechanism has an internal gear that engages with the planetary gear, The internal gear and the outer ring are arranged side by side and housed in a gear case, A power tool in which the outer diameter of the outer ring is smaller than the outer diameter of the internal gear.

9. A power tool according to any one of claims 1 to 8, having a planetary gear mechanism that decelerates the rotation by the output of the motor The planetary gear mechanism has an upstream internal gear, an upstream planetary gear that engages with the upstream internal gear, a downstream internal gear, and a downstream planetary gear that engages with the downstream internal gear, The upstream internal gear, the outer ring, and the downstream internal gear are housed in the gear case in this order, The gear case is provided with a protrusion of the eccentric mechanism that protrudes to the outer ring and abuts against the outer ring, The protrusion makes a part of the inner diameter of the gear case smaller than the outer diameters of the upstream internal gear and the downstream internal gear.

10. A power tool according to any one of claims 1 to 9, a lift mechanism that accumulates energy by the output of the motor, and a driver that moves in the driving direction by the energy accumulated in the lift mechanism and drives a driving tool.

11. An electric power tool according to any one of claims 1 to 10, having a planetary gear mechanism that decelerates the rotation caused by the output of the motor The planetary gear mechanism includes an upstream internal gear, an upstream planetary gear that engages with the upstream internal gear, a downstream internal gear, and a downstream planetary gear that engages with the downstream internal gear, An electric power tool in which the downstream internal gear is provided on the downstream side of the rotation direction restricting mechanism.

Images