JP2018126841A - Fastening tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fastening tool which generates a lower operation sound in fastening work for bolt and nut than a rotary impact tool.SOLUTION: A fastening tool 1 comprises a motor 2, a planetary gear unit 3, a socket 5, and a reaction force reception member 6. The planetary gear unit 3 comprises a first output shaft 343 and a second output shaft 35 which are coaxially about an axis A and can rotate mutually in opposite directions. The socket 5 rotates integrally with the first output shaft 343. The reaction force reception member 6 comprises an arm part 65 capable of abutting on an outside abutting object, and rotates integrally with the second output shaft 35 and reversely to the socket 5 with reaction force during rotation of the socket 5. A rotating speed of the reaction force reception member 6 is determined according to a time from when the motor 2 starts driving in a fastening mode until when fastening torque reaches target torque and a time that a user requires to act to avoid interference between the arm part 65 and an inclusion.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a bolt or nut tightening tool.

  As bolt or nut tightening tools, so-called rotary impact tools such as impact wrenches and impact drivers are known. In the rotary impact tool, a hammer rotated by a motor repeatedly engages and disengages from the anvil, thereby intermittently generating a rotary impact force (impact) on the anvil. The rotary impact tool can tighten bolts and nuts firmly by this operation, but an impact sound is generated when the hammer is engaged with the anvil. On the other hand, Patent Document 1 discloses that an impact sound is reduced by mixing an elastic body with lubricating oil or grease sealed in a hammer case of a rotary impact tool.

JP 2010-284742 A

  According to the rotary impact tool disclosed in Patent Literature 1, although the impact sound at the time of impact occurrence is reduced to some extent, in order to further improve the work environment, further noise generated at the time of fastening work of bolts and nuts is further increased. Mitigation is desired.

  In view of such a situation, an object of the present invention is to provide a tightening tool with quieter operating noise during the tightening operation of bolts and nuts than a rotary impact tool.

  According to one aspect of the present invention, a bolt or nut tightening tool is provided. The tightening tool includes a motor, a planetary speed reducer, a socket, and a reaction force receiving member.

  The planetary speed reducer is driven by a motor. The planetary speed reducer includes a first output shaft and a second output shaft. The first output shaft and the second output shaft are arranged coaxially with respect to a predetermined axis, and are configured to be rotatable in opposite directions.

  The socket is configured to be engageable with a bolt or a nut. The socket is connected to the first output shaft of the planetary speed reducer, and is configured to rotate integrally with the first output shaft. The reaction force receiving member is connected to the second output shaft of the planetary speed reducer, and is configured to rotate in the direction opposite to the socket integrally with the second output shaft by a reaction force when the socket rotates. Further, the reaction force receiving member includes an arm portion that can come into contact with an external contact object.

  The tightening tool is driven so that at least the motor rotates the socket in the forward rotation direction for tightening the bolt or nut, and the drive is stopped when the tightening torque reaches a predetermined target torque set in advance. It is configured to operate in the tightening mode. The rotational speed of the reaction force receiving member is determined when there is an inclusion between the time from when the motor starts driving until the tightening torque reaches the target torque in the tightening mode and the arm portion and the contact object. Further, it is determined according to the time required for the user to perform an operation for avoiding the interference between the arm portion and the inclusion.

  In the tightening tool of this aspect, since the bolt or nut is tightened by rotating the socket, the operation noise is quieter than that of the rotary impact tool, and the reaction force at the time of rotating the socket is opposite to the socket. Since the rotating reaction force receiving member is provided, the reaction force can be received by the contact object via the arm portion. In such a tightening tool, when the arm portion is arranged apart from the contact target object and the tightening operation is started in a state where there is an inclusion between the arm portion and the contact target object, As the receiving member rotates, the arm portion and the inclusion may interfere with each other. Therefore, as in this aspect, the rotational speed of the reaction force receiving member is determined according to the time required for the tightening torque to reach the target torque and the time required for the user to perform an operation to avoid interference. By determining, it is possible to shorten the time required for tightening as much as possible while reducing the possibility of interference between the arm portion and the inclusion.

  In addition, the motor employ | adopted for the clamping tool which concerns on this aspect may be a direct current motor or an alternating current motor, and the presence or absence of a brush is not specifically limited. However, a brushless DC motor is preferably employed from the viewpoint of being small and providing a large output.

  The planetary reduction gear is typically configured mainly with a planetary gear mechanism including a sun gear, a planetary gear, and an internal gear. The planetary speed reducer may include only one planetary gear mechanism, or may include two or more planetary gear mechanisms. The planetary speed reducer of this aspect is configured to have two output shafts (a first output shaft and a second output shaft). Typically, the planetary gear carrier and internal gear may be a first output shaft and a second output shaft, respectively. Note that “the first output shaft and the second output shaft can rotate in opposite directions” means that the reaction force of the torque (reaction) acting on one of the first output shaft and the second output shaft. ) Means that a torque having the same magnitude as this torque (reaction torque) acts on the other output shaft in the reverse direction, and the other output shaft rotates in the reverse direction.

  The socket may be directly connected to the first output shaft or indirectly (in other words, via a separate member). In order to cope with a plurality of types of bolts or nuts, the socket is preferably configured to be detachable from the first output shaft.

  Similar to the socket, the reaction force receiving member may be directly coupled to the second output shaft or indirectly (in other words, via another member). In general, bolts or nuts arranged in the vicinity or other members are used as the contact object with which the arm portion of the reaction force receiving member comes into contact. For this reason, the reaction force receiving member can be replaced with a plurality of types of reaction force receiving members having different shapes and sizes of the arm portions according to the arrangement relationship between the bolt or nut to be tightened and the contact object. It is preferable that the second output shaft is detachable. The reaction force receiving member typically includes a base portion (typically a cylindrical portion) that is directly or indirectly connected to the second output shaft, and an arm portion. A portion extending in a direction (typically radial direction) intersecting the rotation axis of the second shaft is included. For example, the arm portion may be formed in a straight line as a whole, or may be configured to include a bent portion such as an L shape.

  The tightening tool may be operable only in the tightening mode, or may be operable in an operation mode other than the tightening mode. The target torque may be a predetermined uniform value, or may be set by an external operation of the user. Note that the tightening torque can be detected as, for example, a current value of a motor having a predetermined correlation with the tightening torque or a distortion of the second output shaft. Note that the motor drive stop when the tightening torque reaches the target torque is typically controlled by the control unit.

  The operation for the user to avoid interference between the arm portion and the inclusion includes, for example, an operation for moving the inclusion, an operation for stopping the rotation of the reaction force receiving member, and the like. As the time required to perform such an operation, for example, an average reaction time from when a human visually recognizes an object until the body reacts and moves can be employed.

  In one aspect of the present invention, the rotational speed of the reaction force receiving member may be set within a range from 60 rpm to 100 rpm. In view of the reaction time from when a human visually recognizes an object until the body reacts and moves, the rotational speed of the reaction force receiving member is preferably 100 rpm or less. On the other hand, when the rotational speed of the reaction force receiving member is less than 60 rpm, the required tightening time becomes longer than that of the rotary impact tool. Therefore, by ensuring that the rotational speed of the reaction force receiving member is within the range specified in this aspect, the work efficiency equivalent to that of the rotary impact tool is secured while reducing the possibility of interference between the arm portion and the inclusion. Can do. The rotational speed of the reaction force receiving member is more preferably set within a range from 70 rpm to 90 rpm, and more preferably approximately 80 rpm.

  In one aspect of the present invention, the tightening tool may further include a housing, a handle, and a battery. The housing houses the motor and at least a part of the planetary speed reducer. The handle protrudes from the housing in a direction crossing a predetermined axis and is configured to be gripped by the user. The battery is detachably mounted on a battery mounting portion provided at the end of the handle on the protruding side. The center of gravity of the tightening tool when the battery is attached may be located in the handle. When the position of the center of gravity is in the handle as in this aspect, the user can easily operate the tightening tool regardless of the direction in which the user performs the tightening operation. In addition, it is more preferable that the center of gravity is in the vicinity of a trigger configured to be able to be pressed by a finger in the handle. In addition, the center of gravity arrangement of this aspect is a tightening tool with a total weight of 2.5 kg or less when a battery is attached (that is, it can be used in various directions while holding the tightening tool with one hand) This is particularly effective when applied to a high-performance fastening tool).

  In one aspect of the present invention, the tightening tool is configured to stop the rotation of the reaction force receiving member when the operation member configured to be able to be pressed by the user and the pressing operation of the operation member are released. A brake part may be further provided. According to this aspect, when the inclusion is present, the user can release the pressing operation of the operation member as an operation for avoiding interference between the arm portion of the reaction force receiving member and the inclusion. There is a possibility that the motor rotates by inertia and the reaction force receiving member rotates further only by stopping the motor, but in this embodiment, since the brake portion stops the rotation of the reaction force receiving member, Interference can be surely avoided.

  In one aspect of the present invention, the tightening tool may further include an illumination device configured to irradiate light toward a predetermined region including the arm portion. According to this aspect, the user can easily confirm the proximity state of the arm unit to the contact object or the inclusion even in a dimly lit workplace or the like.

  In one aspect of the present invention, the tightening tool may further include a torque setting member configured to be able to set a target torque by a user's external operation. According to this aspect, the user can set an appropriate target torque in accordance with the type of bolt or nut (screw nominal diameter or the like) to be tightened with the tightening tool.

  In one aspect of the present invention, the tightening tool may be configured to be operable in a plurality of operation modes including a tightening mode and a loosening mode. The loosening mode is an operating mode in which the motor is driven to rotate the socket in the reverse direction to loosen the bolt or nut. The torque of the first output shaft in the loosening mode may be set larger than the maximum value of the torque of the first output shaft in the tightening mode. When a bolt or nut is tightened and then tightened, a larger torque is required than when tightening. According to this aspect, since the torque of the first output shaft in the loosening mode is set to be larger than the maximum value of the torque in the tightening mode, the bolt or nut can be loosened with an appropriate torque even in the loosening mode. .

It is a right view of a fastening tool. It is a rear view of a fastening tool. It is a top view of a clamping tool. It is a longitudinal cross-sectional view of a fastening tool. It is a longitudinal cross-sectional view of the planetary gear unit with the reaction force receiving member attached. It is a partial longitudinal cross-sectional view of the planetary gear unit in a state where a reaction force receiving member is mounted. It is sectional drawing in the VII-VII line of FIG. It is sectional drawing in the VIII-VIII line of FIG. It is sectional drawing in the IX-IX line of FIG. It is sectional drawing in the XX line of FIG. It is a perspective view of a planetary gear unit in a state where a reaction force receiving member is mounted. It is a graph which shows the time-dependent change of the axial force at the time of the fastening operation | work of the conventional impact wrench and the fastening tool which concerns on embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. In the following embodiment, the tightening tool 1 for tightening the nut 92 with respect to the bolt 91 inserted through the through hole of the work material 90 is illustrated.

  First, a schematic configuration of the tightening tool 1 will be described with reference to FIG. As shown in FIG. 1, the outline of the tightening tool 1 is mainly formed by a main body housing 11, a part of the planetary gear unit 3, and a handle 15. The main body housing 11 and the planetary gear unit 3 extend along a predetermined axis A in a state where a part of the planetary gear unit 3 is accommodated in the main body housing 11 and a part is exposed to the outside. A socket 5 that can be engaged with a nut 92 and a reaction force receiving member 6 are connected to one end of the planetary gear unit 3 on the exposed side in the direction of the axis A. The handle 15 is configured to be gripped by the user and protrudes from the main body housing 11 in a direction intersecting the axis A. A trigger 151 that can be pressed by the user is provided at the base end of the handle 15. A rechargeable battery 8 is detachably mounted on the protruding end of the handle 15 via a battery mounting portion 17.

  When the user engages the socket 5 with the nut 92 screwed to the bolt 91 to some extent and presses the trigger 151, the tightening tool 1 tightens the nut 92. At this time, the reaction force receiving member 6 abuts against an abutting object such as an adjacent nut 92, so that the reaction force during rotation of the socket 5 can be received by the abutting object.

  In the following, regarding the direction of the tightening tool 1, for convenience of explanation, the axis A direction is defined as the front-rear direction of the tightening tool 1, and the side on which the socket 5 is disposed is defined as the front side, and the opposite side is defined as the rear side. To do. Further, a direction perpendicular to the axis A and corresponding to the extending direction of the handle 15 is defined as a vertical direction, a side where the main body housing 11 is disposed is defined as an upper side, and a side where the battery 8 is mounted is defined as a lower side.

  Hereinafter, the detailed configuration of the tightening tool 1 will be described with reference to FIGS.

  As shown in FIG. 4, the main body housing 11 mainly accommodates the motor 2 and a part of the planetary gear unit 3. In the present embodiment, a small and high output brushless DC motor is employed as the motor 2. The motor 2 is disposed in the rear end portion of the main body housing 11 so that the rotation shaft of the output shaft 21 that rotates together with the rotor (not shown) extends on the axis A. The planetary gear unit 3 is configured as a planetary speed reducer and is arranged on the front side of the motor 2. The planetary gear unit 3 is driven by the motor 2 and transmits power to the socket 5 and the reaction force receiving member 6. The planetary gear unit 3, the socket 5, and the reaction force receiving member 6 will be described in detail later.

  As shown in FIGS. 1, 2, and 4, the operation mode of the tightening tool 1 is set between the tightening mode and the loosening mode at the lower end of the main body housing 11 according to the external operation of the user. A changeover switch 111 for switching is provided. The tightening mode is an operation mode in which the motor 2 is driven so as to rotate the socket 5 in the normal rotation direction for tightening the nut 92 (normally driven). On the other hand, the loosening mode is an operation mode in which the motor 2 is driven so as to rotate the socket 5 in the direction opposite to the normal rotation direction, that is, in the reverse rotation direction in which the nut 92 is loosened (reversely driven). .

  In the present embodiment, the changeover switch 111 is configured as a mode setting member that can set either the tightening mode or the loosening mode. Specifically, the changeover switch 111 is held by the main body housing 11 so as to be movable in the left-right direction, and outputs a signal corresponding to the arrangement position. The controller 7 (see FIG. 4), which will be described later, is a position where the changeover switch 111 is pressed from the right side, and the left end portion protrudes leftward from the main body housing 11 as shown in FIG. When the motor 2 is disposed, the motor 2 is driven to rotate forward in the tightening mode. Although not shown, conversely, when the changeover switch 111 is pressed from the left side and the right end portion is disposed at a position protruding rightward from the main body housing 11 (hereinafter referred to as a right position), the controller 7 The motor 2 is driven reversely in the loose mode. The changeover switch 111 may be configured to be able to set other operation modes in addition to the tightening mode and the loosening mode.

  As shown in FIGS. 3 and 4, a torque setting dial 113 capable of setting a target torque at the time of tightening work is provided on the upper surface of the main body housing 11 by an external operation of the user. Although details will be described later, the target torque refers to a threshold value of torque used as a criterion for determining whether or not the nut 92 has been tightened. In the present embodiment, the torque setting dial 113 is configured to be capable of adjusting the target torque in a stepless manner in accordance with the rotational position (the amount of rotation from the reference position). Numbers up to are shown.

  As shown in FIGS. 1 and 4, a lighting unit 115 is provided at the front end of the lower end portion of the main body housing 11. The illumination unit 115 of the present embodiment is mainly composed of a light emitting diode (LED) as a light source and a case made of a translucent material (transparent resin, glass, etc.) that accommodates the LED. The illumination unit 115 has a light irradiation direction set so that light emitted from the LED illuminates a predetermined area in front. In the present embodiment, the predetermined area is set so as to include a work area where tightening by the socket 5 is performed and a rotational movement range of an arm portion 65 of the reaction force receiving member 6 described later.

  As shown in FIGS. 1 and 4, the handle 15 is configured to be gripped by a user, and has a trigger 151 that can be pressed with a finger on the front side of the upper end. A switch 152 is accommodated inside the handle 15. The switch 152 is turned on in response to the pressing operation of the trigger 151 and outputs an on signal. When the trigger 151 is released, the switch 152 is turned off and outputs an off signal.

  Further, as shown in FIG. 4, a battery mounting portion 17 configured to be detachable from the battery 8 is provided at the lower end portion of the handle 15 as described above. The total weight of the tightening tool 1 when the battery 8 is mounted on the battery mounting portion 17 is about 2 kg. Further, the center of gravity G of the tightening tool 1 when the battery 8 is mounted is located in the handle 15 as shown in FIGS. More specifically, the center of gravity G is substantially at the same position as the lower end portion of the trigger 151 in the up-down direction, and is slightly behind the trigger 151 in the front-back direction. The user holds the handle 15 and directs the tightening tool 1 in various directions to perform the tightening operation. When the center of gravity G is in the handle 15, the user can tighten the tightening tool 1 in any direction. Easy to operate. In particular, in this embodiment, since the center of gravity G is in the vicinity of the trigger 151 in the handle 15, the tightening tool 1 can exhibit excellent operability.

  A controller 7 that controls the tightening tool 1 such as drive control of the motor 2 is accommodated in the lower end portion of the handle 15 (above the battery mounting portion 17). In the present embodiment, the controller 7 is composed of a microcomputer including a CPU, ROM, RAM, and the like. The controller 7 is electrically connected to the changeover switch 111, the torque setting dial 113, the illumination unit 115, the switch 151 of the trigger 151, and the like through a wiring (not shown). Further, as shown in FIG. 2, a U-shaped hook 157 is attached to the left side surface of the lower end portion of the handle 15 with a screw. The hook 157 is configured to be hookable on a user's belt or the like.

  Hereinafter, detailed configurations of the planetary gear unit 3, the socket 5, and the reaction force receiving member 6 will be described in order.

  First, the planetary gear unit 3 will be described. As shown in FIG. 5, the planetary gear unit 3 of the present embodiment includes four planets of a first planetary gear mechanism 31, a second planetary gear mechanism 32, a third planetary gear mechanism 33, and a fourth planetary gear mechanism 34. A gear mechanism and a gear housing 36 supporting these four sets of planetary gear mechanisms are provided.

  As shown in FIGS. 4, 5, and 7, the first planetary gear mechanism 31 includes a sun gear 311, a carrier 312, five planetary gears 315, and an internal gear 317. The first planetary gear mechanism 31 is configured with the output shaft 21 of the motor 2 rotating around the axis A as an input shaft, and the sun gear 311 is fixed to the front end of the output shaft 21. The carrier 312 rotatably supports the five planetary gears 315 that mesh with the sun gear 311 and has a shaft portion 313 that is disposed coaxially with the axis A. The internal gear 317 is arranged coaxially with the axis A and meshes with the planetary gear 315.

  As shown in FIGS. 5 and 8, the second planetary gear mechanism 32 includes a sun gear 321, a carrier 322, five planetary gears 325, and an internal gear 327. The sun gear 321 is fixed to the shaft portion 313 of the carrier 312 of the first planetary gear mechanism 31. The carrier 322 rotatably supports five planetary gears 325 that mesh with the sun gear 321 and has a shaft portion 323 arranged coaxially with the axis A. The internal gear 327 is arranged coaxially with the axis A and meshes with the planetary gear 325.

  Note that the internal gear 317 of the first planetary gear mechanism 31 and the internal gear 327 of the second planetary gear mechanism 32 are both held by a cylindrical holding sleeve 351. More specifically, as shown in FIG. 7, a plurality of protrusions 318 extending in the direction of the axis A are formed on the outer peripheral portion of the internal gear 317, while the inner peripheral portion of the rear portion of the holding sleeve 351 is formed. Is formed with a plurality of grooves 352 that extend in the direction of the axis A and can be engaged with the protrusions 318. Although not shown, a protrusion similar to the internal gear 317 is formed on the outer peripheral portion of the rear end portion of the internal gear 327. Therefore, the internal gears 317 and 327 are fitted into the holding sleeve 351, whereby the internal gears 317 and 327 are held in a state where the rotation around the axis A is prohibited by the holding sleeve 351.

  As shown in FIGS. 5 and 9, the third planetary gear mechanism 33 includes a sun gear 331, a carrier 332, three planetary gears 335, and an internal gear 337. The sun gear 331 is fixed to the shaft portion 323 of the carrier 322 of the second planetary gear mechanism 32. The carrier 332 rotatably supports the three planetary gears 335 that mesh with the sun gear 331 and has a shaft portion 333 that is disposed coaxially with the axis A. The internal gear 337 is arranged coaxially with the axis A and meshes with the planetary gear 335.

  As shown in FIGS. 5 and 10, the fourth planetary gear mechanism 34 includes a sun gear 341, a carrier 342, three planetary gears 345, and an internal gear 337. The sun gear 341 is fixed to the shaft portion 333 of the carrier 332 of the third planetary gear mechanism 33. The carrier 342 rotatably supports the three planetary gears 345 that mesh with the sun gear 341 and has a shaft portion 343 that is disposed coaxially with the axis A. The internal gear 337 is a member common to the third planetary gear mechanism 33 and the fourth planetary gear mechanism 34, and at least the planetary gear 335 of the third planetary gear mechanism 33 and the second planetary gear mechanism 33 in the direction of the axis A (front-rear direction). The planetary gear 345 of the four planetary gear mechanism 34 is formed to have a length that can be accommodated.

  In addition, unevenness is formed at the rear end portion of the internal gear 337. On the other hand, irregularities are similarly formed on the front end portions of the holding sleeves 351 of the internal gears 317 and 327 described above. The internal gear 337 is integrated with the internal gears 317 and 327 in the direction of the axis A via the holding sleeve 351 by fitting the unevenness of the internal gear 337 to the unevenness of the holding sleeve 351. In other words, the internal gears 317, 327, and 337 and the holding sleeve 351 as a whole have one internal gear (hereinafter referred to as the internal gear unit 35) that is common to the first planetary gear mechanism 31 to the fourth planetary gear mechanism 34. It is composed.

  As shown in FIG. 5, the gear housing 36 that supports the first planetary gear mechanism 31 to the fourth planetary gear mechanism 34 is mainly configured by a rear housing 361, a front housing 363, and a retaining sleeve 367. Yes.

  The rear housing 361 is formed in a bottomed cylindrical shape. A holding sleeve 351 is accommodated in the rear housing 361 in a state where rotation around the axis A is permitted. The output shaft 21 of the motor 2 to which the sun gear 311 is fixed is inserted into a through hole 362 formed in the bottom of the rear housing 361 (see FIG. 4).

  The front housing 363 is formed in a cylindrical shape having a larger diameter than the rear housing 361, and the front end portion of the rear housing 361 is fitted into the rear end portion of the front housing 363. In this state, the front housing 363 and the rear housing 361 are fixed and integrated with screws (not shown). The retaining sleeve 367 is formed in a cylindrical shape having a flange 368 at the front end. The retaining sleeve 367 is fitted from the front side between the outer peripheral surface of the internal gear 337 and the inner peripheral surface of the front housing 363 so that the flange 368 contacts the front end of the front housing 363. The front end portion of the internal gear (internal gear unit 35) protrudes forward from the retaining sleeve 367 and is exposed to the outside.

  Note that the retaining sleeve 367 is restricted from moving with respect to the front housing 363 by O-rings 369 mounted in three annular grooves formed in the circumferential direction of the outer peripheral portion thereof. A flange 338 projecting radially outward is provided at the rear end of the internal gear 337. When the retaining sleeve 367 is fitted, the flange 338 is connected to the front end of the rear housing 361 and the rear retaining sleeve 367. It is arranged between the ends. As a result, the movement of the internal gear 337 in the direction of the axis A (front-rear direction) is restricted, and the rotation around the axis A is allowed and held by the retaining sleeve 367. As described above, the holding sleeve 351 is also held by the rear housing 361 in a state where rotation around the axis A is permitted. That is, the internal gear unit 35 is held by the gear housing 36 (the rear housing 361, the front housing 363, and the retaining sleeve 367) while being allowed to rotate about the axis A.

  As shown in FIGS. 9 to 11, at four locations in the circumferential direction of the rear end portion of the front housing 363, fixing portions 364 that protrude radially outward from the cylindrical front side portion of the front housing 363 are provided. It has been. The fixing portion 364 has a through hole 365 extending in the front-rear direction. As shown in FIG. 1, the screw 37 is inserted into the through hole 365 from the front side of the fixing portion 364 and screwed into a screw hole (not shown) formed in the main body housing 11, so that the gear housing 36 is It is fixed to the housing 11.

  In the planetary gear unit 3 configured as described above, the power of the motor 2 is transmitted in the order of the first planetary gear mechanism 31, the second planetary gear mechanism 32, the third planetary gear mechanism 33, and the fourth planetary gear mechanism 34. Is done. Specifically, as the motor 2 is driven, the sun gear 311 of the first planetary gear mechanism 31 rotates integrally with the output shaft 21. The planetary gear 315 rotates around the sun gear 311 while rotating, thereby rotating the carrier 312 (shaft portion 313) around the axis A in the same direction as the output shaft 21. In the second planetary gear mechanism 32, the third planetary gear mechanism 33, and the fourth planetary gear mechanism 34, the same transmission is performed, and the carriers 322, 332, and 342 rotate in the same direction as the output shaft 21.

  On the other hand, in the first planetary gear mechanism 31 to the fourth planetary gear mechanism 34, the reaction force during rotation of the carriers 312, 322, 332, 342 is transmitted via the planetary gears 315, 325, 335, 345 to the gear housing 36. The internal gear unit 35 held by the carrier 312, 322, 332, and 342 is rotated in the opposite direction. That is, in the planetary gear unit 3, the shaft portion 343 of the carrier 342 and the internal gear unit 35 of the fourth planetary gear mechanism 34 located on the most downstream side of the power transmission path serve as two final output shafts that rotate in opposite directions. It is configured. Therefore, hereinafter, the shaft portion 343 and the internal gear unit 35 of the carrier 342 of the fourth planetary gear mechanism 34 are also referred to as a first output shaft 343 and a second output shaft 35, respectively.

  Hereinafter, the socket 5 will be described with reference to FIGS. 4 and 11. In the present embodiment, the socket 5 is configured to be detachable from the first output shaft 343 of the planetary gear unit 3 (the shaft portion 343 of the carrier 342). In the present embodiment, a well-known configuration is adopted as a configuration that allows the socket 5 to be attached to and detached from the first output shaft 343, and therefore, a simple description will be given here.

  As shown in FIG. 11, the first output shaft 343 has a socket mounting portion 346 formed in a prismatic shape at the front end. The socket mounting portion 346 is provided with a through hole 347 that extends in a direction orthogonal to the axis A and through which a pin (not shown) for retaining is inserted. On the other hand, as shown in FIG. 4, the socket 5 is formed in a cylindrical shape as a whole. The inner peripheral portion of the rear end portion of the socket 5 constitutes a shaft mounting portion 51 into which the socket mounting portion 346 can be fitted. The rear end portion of the socket 5 is fitted to the outside of the socket mounting portion 346, a pin is inserted into a through hole (not shown) provided in the socket 5 and the through hole 347, and the pin is an O-ring from the outer peripheral side of the socket 5. The socket 5 is attached to the first output shaft 343 by being prevented from being detached by (not shown).

  Further, the inner peripheral portion of the front end portion of the socket 5 constitutes a nut engaging portion 55 that can engage with the nut 92. A plurality of types of sockets 5 that can be attached to and detached from the tightening tool 1 are prepared so as to be compatible with nuts 92 having different sizes (diameters). The user may attach an appropriate socket 5 to the first output shaft 343 according to the size of the nut 92 actually used.

  Hereinafter, the reaction force receiving member 6 will be described with reference to FIGS. 5, 6, and 11. In the present embodiment, the reaction force receiving member 6 is configured to be detachable from the second output shaft (internal gear unit) 35 of the planetary gear unit 3 via a connecting member 38.

  As shown in FIG. 11, a plurality of locking recesses 354 are provided at the front end portion of the internal gear 337 so as to be separated from each other in the circumferential direction. The locking recess 354 is a recess that is recessed in a rectangular shape from the front end of the internal gear 337 toward the rear. As shown in FIGS. 5 and 6, the inner peripheral portion of the front end portion is formed with a thinner peripheral wall (larger inner diameter) than other portions, and the fitting recess 353 into which the connecting member 38 is fitted. Is configured. Further, as shown in FIG. 6, an annular groove 355 is provided in the circumferential direction on the inner peripheral portion of the front end portion of the internal gear 337.

  As shown in FIGS. 5 and 6, the connecting member 38 includes a gear fitting portion 381 constituting the rear end portion of the connecting member 38 and a reaction force receiving mounting portion 385 constituting the front end portion. The gear fitting portion 381 is formed in a cylindrical shape that can be fitted into the fitting recess 353 formed in the internal gear 337. A plurality of locking projections 383 are provided at the front end portion of the gear fitting portion 381 so as to be separated from each other in the circumferential direction. The locking projection 383 is formed in a rectangular shape that can be fitted into the locking recess 354 and is provided so as to protrude radially outward. The connecting member 38 has a gear fitting portion 381 fitted in the fitting concave portion 353 in a state where the locking convex portion 383 is fitted in the locking concave portion 354, and further, by a retaining ring 389 fitted in the annular groove 355. The inner gear 337 is fixed. That is, the connecting member 38 is integrally connected to the internal gear 337.

  As shown in FIG. 11, the reaction force receiving member 6 includes a base portion 61 configured to be detachable from the connecting member 38 and an arm portion 65 protruding from the base portion 61.

  The base portion 61 has a mounting hole 611 having a hexagonal cross section that can be fitted to the outer periphery of the reaction force receiving mounting portion 385 of the connecting member 38. The arm portion 65 is formed integrally with the base portion 61, and as a whole, extends radially outward toward the oblique front of the base portion 61. Specifically, the arm portion 65 includes a first portion 651 that projects diagonally forward from the front end of the base portion 61 and radially outward with respect to the axis A, and a second portion that projects radially outward from the tip of the first portion 651. Part 653. As shown in FIG. 2, the arm portion 65 is formed to have a length that can be seen by projecting outward from the outline of the main body housing 11 when viewed in the direction of the axis A. Of the arm portion 65, the second portion 653 is configured as an abutting portion that abuts against the abutting object during the tightening operation. The reaction force receiving member 6 is screwed into the connecting member 38 via a through hole (not shown) formed in the base portion 61 in a state where the base portion 61 is fitted to the outer periphery of the reaction force receiving mounting portion 385. (Not shown).

  A plurality of types of reaction force receiving members 6 with different lengths and shapes of the arm portions 65 are prepared so as to correspond to various arrangement relationships between the nuts 92 to be fastened and the contact objects. The user may attach the appropriate reaction force receiving member 6 to the second output shaft 35 via the connecting member 38 according to the arrangement relationship between the nut 92 to be fastened and the contact object.

  Hereinafter, a tightening operation and a loosening operation of the nut 92 by the tightening tool 1 will be described in order.

  When performing a tightening operation, the user first inserts the nut 92 into the bolt 91 inserted through the through hole of the work material 90 to a certain extent (typically, the nut 92 is completely the tip of the bolt 91). (Until the state of being screwed to the end opposite to the head). In addition, the user presses the changeover switch 111 from the right side and places it in the left position, thereby setting the operation mode of the tightening tool 1 to the tightening mode. Further, the torque setting dial 113 is operated to set an appropriate target torque according to the types of the bolt 91 and the nut 92. In the tightening tool 1 of the present embodiment, the target torque can be set up to a maximum of 100 N · m.

  Thereafter, as shown in FIG. 4, the user presses the trigger 151 by engaging the nut engaging portion 55 of the socket 5 with the nut 92. When the switch 152 is turned on in response to the pressing operation of the trigger 151, the controller 7 starts the forward rotation driving of the motor 2 after turning on the LED of the illumination unit 115. In the present embodiment, the motor 2 is operated when the tightening torque reaches the target torque or when the pressing operation of the trigger 151 is released and the switch 152 is turned off before the tightening torque reaches the target torque. Then, the forward rotation driving of the motor 2 is stopped. At the time of normal rotation driving in the tightening mode, the motor 2 is normally rotated at a rotation speed (number of rotations) set in advance corresponding to the tightening mode. In the present embodiment, the rotational speed of the motor 2 during forward rotation driving is set so that the rotational speed of the reaction force receiving member 6 (second output shaft 35) is within a range of 60 rpm to 100 rpm.

  When the motor 2 is driven to rotate forward, the socket 5 connected to the first output shaft (shaft portion) 343 of the planetary gear unit 3 is rotated in the forward rotation direction in which the nut 92 is tightened. At this time, since a reverse torque acts as a reaction force on the second output shaft (internal gear unit) 35 of the planetary gear unit 3, the reaction force receiving member 6 connected to the second output shaft 35 is provided. At this point, the axis 5 starts to rotate in the opposite direction to the socket 5. When the reaction force receiving member 6 rotates and the second portion 653 comes into contact with the contact object (the nut 92 in the example of FIG. 2) disposed adjacent to the nut 92 to be fastened, the socket 5 rotates. The reaction object receives the reaction force via the reaction force receiving member 6.

  When the nut 92 is seated on the work material 90 (or a washer disposed between the nut 92 and the work material 90), the tightening torque increases and reaches the target torque. In the present embodiment, the controller 7 uses the drive current value of the motor 2 detected by a current detection amplifier (not shown) as the tightening torque and compares it with the current value corresponding to the set target torque. Determine the end of tightening. Since this method is publicly known, detailed description thereof is omitted here. Other known methods such as a method of comparing the actual tightening torque measured with the strain gauge with the target torque may be employed. When the tightening torque reaches the target torque, the controller 7 terminates the tightening process by stopping the driving of the motor 2. Thereafter, when the user releases the pressing operation of the trigger 151, the controller 7 turns off the LED of the illumination unit 115 after a predetermined period.

  Note that when the pressing operation of the trigger 151 is released and the switch 152 is turned off before the tightening torque reaches the target torque, the controller 7 stops driving the motor 2. The controller 7 may stop the driving of the motor 2 after temporarily rotating the motor 2 in reverse to prevent the reaction force receiving member 6 from continuing to rotate due to inertia. In this case, the controller 7 turns off the LED of the lighting unit 115 after a predetermined period has elapsed since the driving of the motor 2 was stopped.

  When performing the loosening operation, the user presses the changeover switch 111 from the left side and places it in the right position, thereby setting the operation mode of the tightening tool 1 to the loosening mode, and the nut engaging portion 55 of the socket 5. Is engaged with the nut 92 and the trigger 151 is pressed. The controller 7 starts reverse rotation driving of the motor 2 after turning on the LED of the illumination unit 115. When loosening the nut 92 that has been tightened, a torque larger than the tightening torque at the time of tightening is required. Therefore, in the present embodiment, a value higher than the maximum value of torque in the tightening mode (that is, a value higher than 100 N · m that can be set as the target torque) is set as the torque value at the time of reverse rotation in the loosening mode. ing.

  In the loosening mode, the controller 7 stops driving the motor 2 when the pressing operation of the trigger 151 is released and the switch 152 is turned off, and then turns off the LED when a predetermined period has elapsed. In the loosening mode, as in the tightening mode, in order to prevent the reaction force receiving member 6 from continuing to rotate due to inertia, the controller 7 temporarily drives the motor 2 to rotate forward and then drives the motor 2. May be stopped.

  In the tightening tool 1 according to the embodiment configured as described above, a striking sound is not generated when a rotary impact tool (for example, an impact wrench) is used. That is, according to the present embodiment, the tightening tool 1 with a quieter operating sound than the rotary impact tool is realized.

  Hereinafter, with reference to FIG. 12, in the tightening tool 1 of the present embodiment, the rotation force of the reaction force receiving member 6 is set to 60 rpm, 80 rpm, and 100 rpm, respectively, and the tightening operation is performed. A comparison result of changes over time in axial force (fastening force) when fastening work is performed using an impact wrench with a force receiving member (rotation speed of the reaction force receiving member is 2,800 rpm) will be described. In order to compare the time required to reach a predetermined axial force F (in other words, the time required for the tightening process to be completed after the tightening torque reaches the target torque), the bolts classified as M12 are used. A condition was adopted in which the nut 92 was seated by tightening the three screw threads with the tightening tool 1 or the impact wrench while the nut 92 was manually tightened to 91. That is, when the tightening process is completed, three threads of the bolt 91 are projected from the nut 92.

  As shown in FIG. 12, in the case of the impact wrench, the nut 92 is seated and the axial force starts to rise 0.064 seconds after starting the tightening, but until the predetermined axial force F is reached. It takes about 4 seconds. When the rotational speed is set to 60 rpm with the tightening tool 1 of the present embodiment, it takes 3 seconds from the start of tightening to the seating, but thereafter the axial force increases rapidly, and about 3 A predetermined axial force F is reached after 3.5 seconds. Further, when the rotational speed is 80 rpm with the tightening tool 1 of the present embodiment, the time until seating is about 2.25 seconds, and the time until reaching the predetermined axial force F is about 2.75. Seconds. When the rotational speed is 100 rpm with the tightening tool 1 of the present embodiment, the time until seating is about 1.8 seconds, and the time until reaching the predetermined axial force F is about 2.3 seconds. is there.

  From the above comparison results, when the rotational speed of the reaction force receiving member 6 (second output shaft 35) is 60 rpm or more, the tightening tool 1 completes the tightening operation in a time equivalent to or shorter than the impact wrench. You can see that On the other hand, when the arm portion 65 is disposed away from the contact target object and the tightening operation is started in the state where the inclusion exists between the arm portion 65 and the contact target object, the reaction force receiving member 6 is started. As the arm rotates, there is a possibility that the arm portion 65 and the inclusions interfere with each other. As the rotational speed of the reaction force receiving member 6 (that is, the rotational speed of the socket 5 (first output shaft 343)) is increased, the time required for tightening can be shortened. In view of the reaction time required for the reaction to move, the rotational speed of the reaction force receiving member is preferably 100 rpm or less. On the other hand, when the rotational speed of the reaction force receiving member 6 is less than 60 rpm, the required tightening time becomes longer than that of the rotary impact tool.

  Therefore, in the present embodiment, by setting the rotational speed of the reaction force receiving member 6 within the range of 60 rpm to 100 rpm, the possibility of interference between the arm portion 65 and the inclusion is reduced, or equivalent to the rotary impact tool or Further work efficiency can be ensured. The rotational speed of the reaction force receiving member 6 is more preferably set within the range of 70 to 90 rpm, and more preferably about 80 rpm.

  Furthermore, when the pressing operation of the trigger 151 is released, the controller 7 can function as a brake unit that stops the rotation of the reaction force receiving member 6 by controlling the driving of the motor 2. Therefore, the user only releases the pressing operation of the trigger 151 as an operation for avoiding interference between the arm portion 65 and the inclusion when there is an inclusion between the arm portion 65 and the contact object. It's okay. If the motor 2 is simply stopped, the motor 2 may rotate due to inertia and the reaction force receiving member 6 may further rotate. However, the controller 7 temporarily rotates the output shaft 21 of the motor in the original rotation direction. If the rotation of the reaction force receiving member 6 is stopped by rotating it in the opposite direction, interference can be avoided more quickly and reliably. Instead of controlling the motor 2 by the controller 7, when the pressing operation of the trigger 151 is released, the reaction force receiving member 6 or the second output shaft 35 is acted on to stop the reaction force receiving member 6 from rotating. A configured mechanical brake may be provided.

  Further, the tightening tool 1 of the present embodiment includes an illumination unit 115 that illuminates a predetermined area including a work area where the tightening by the socket 5 is performed and a rotational movement range of the arm portion 65 of the reaction force receiving member 6. . Therefore, the user can easily confirm the proximity state of the arm portion 65 to the contact object or the inclusion even in a dim work place. Further, in the present embodiment, the lighting unit 115 is turned on before driving the motor 2 and is turned off after the driving of the motor 2 is stopped. Therefore, the user can easily confirm the working state and the arrangement of the arm portion 65 with respect to the contact object or the inclusion before and after starting the tightening operation.

  In the present embodiment, the tightening tool 1 includes a torque setting dial 113 configured to be able to set a target torque by an external operation of the user. Therefore, the user can set an appropriate target torque according to the types of the bolts 91 and the nuts 9 to be tightened by the tightening tool 1. In the loose mode, the torque value of the first output shaft 343 is set to a value higher than the maximum torque value in the tightening mode (that is, a value higher than 100 N · m that can be set as the target torque). Therefore, the nut 92 after tightening can be loosened with a sufficiently large torque. Note that the torque value in the loose mode is not a uniform value, and the controller 7 may automatically set a value larger than the set target torque (for example, a value larger than the target value by a predetermined value). Good.

  Correspondence relations between the constituent elements of the embodiment and the modifications thereof and the constituent elements of the invention are shown below. The tightening tool 1 is a configuration example corresponding to the “tightening tool” of the present invention. The motor 2 is a configuration example corresponding to the “motor” of the present invention. The planetary gear unit 3 is a configuration example corresponding to the “planetary speed reducer” of the present invention. The shaft portion 343 of the fourth planetary gear mechanism 34 is a configuration example corresponding to the “first output shaft” of the present invention. The internal gear 337 (internal gear unit 35) of the fourth planetary gear mechanism 34 is a configuration example corresponding to the “second output shaft” of the present invention. The socket 5 is a configuration example corresponding to the “socket” of the present invention. The reaction force receiving member 6 and the arm portion 65 are configuration examples corresponding to the “reaction force receiving member” and the “arm portion” of the present invention, respectively.

  The main body housing 11 is a configuration example corresponding to the “housing” of the present invention. The handle 15 is a configuration example corresponding to the “handle” of the present invention. The battery mounting portion 17 is a configuration example corresponding to the “battery mounting portion” of the present invention. The battery 8 is a configuration example corresponding to the “battery” of the present invention. The trigger 151 is a configuration example corresponding to the “operation member” of the present invention. The controller 7 is a configuration example corresponding to the “brake part” of the present invention. The lighting unit 115 is a configuration example corresponding to the “lighting device” of the present invention. The torque setting dial 113 is a configuration example corresponding to the “torque setting member” of the present invention.

  The above embodiment is merely an example, and the tightening tool according to the present invention is not limited to the configuration of the illustrated tightening tool 1. In view of the gist of the present invention and the above embodiment, the following aspects are further constructed. Each of the following aspects can be employed in combination with other aspects, the fastening tool 1 shown in the embodiment, or the invention described in each claim.

[Aspect 1]
The rotational speed of the reaction force receiving member may be set within a range from 70 rpm to 90 rpm.
[Aspect 2]
The rotational speed of the reaction force receiving member may be set to approximately 80 rpm.
[Aspect 3]
The tightening tool may be configured as a tightening tool having a total weight of 2.5 kg or less when the battery is mounted.

1: Tightening tool 11: Body housing 111: Changeover switch 113: Torque setting dial 115: Lighting unit 15: Handle 151: Trigger 152: Switch 157: Hook 17: Battery mounting part 2: Motor 21: Output shaft 3: Planetary gear Unit 31: First planetary gear mechanism 311: Sun gear 312: Carrier 313: Shaft portion 315: Planetary gear 317: Internal gear 318: Projection 32: Second planetary gear mechanism 321: Sun gear 322: Carrier 323: Shaft portion 325 : Planetary gear 327: Internal gear 33: Third planetary gear mechanism 331: Sun gear 332: Carrier 333: Shaft portion 335: Planetary gear 337: Internal gear 338: Flange 34: Fourth planetary gear mechanism 341: Sun gear 342: Carrier 343: Shaft portion (first Power shaft)
345: Planetary gear 346: Socket mounting portion 347: Through hole 35: Internal gear unit (second output shaft)
351: holding sleeve 352: groove 353: fitting recess 354: locking recess 355: annular groove 36: gear housing 361: rear housing 362: through hole 363: front housing 364: fixing portion 365: through hole 367: retaining Sleeve 368: Flange 369: O-ring 37: Screw 38: Connecting member 381: Gear fitting portion 383: Locking convex portion 385: Reaction force receiving mounting portion 389: Retaining ring 5: Socket 51: Shaft mounting portion 55: Nut engagement Joint part 6: Reaction force receiving member 61: Base part 611: Mounting hole 65: Arm part 651: First part 653: Second part 7: Controller 8: Battery 90: Work material 91: Bolt 92: Nut A: Axis G : Center of gravity

Claims (7)

A bolt or nut tightening tool,
A motor,
A planetary speed reducer driven by the motor, wherein the planetary speed reducer includes a first output shaft and a second output shaft that are coaxially arranged with respect to a predetermined axis and are rotatable in opposite directions. When,
A socket configured to be engageable with the bolt or the nut, coupled to the first output shaft, and configured to rotate integrally with the first output shaft;
A reaction force receiving member coupled to the second output shaft and configured to rotate in a direction opposite to the socket integrally with the second output shaft by a reaction force during rotation of the socket;
The reaction force receiving member includes an arm portion capable of contacting an external contact object,
The tightening tool is driven at least when the motor is driven to rotate the socket in the forward rotation direction for tightening the bolt or the nut, and the tightening torque reaches a predetermined target torque. It is configured to be able to operate in a tightening mode in which driving is stopped,
The rotational speed of the reaction force receiving member is interposed between the time from the start of driving the motor until the tightening torque reaches the target torque in the tightening mode, and the arm portion and the contact object. A tightening tool characterized by being determined according to a time required for a user to perform an operation for avoiding interference between the arm portion and the inclusion when an object is present. The tightening tool according to claim 1,
The tightening tool, wherein the rotation speed is set in a range from 60 rpm to 100 rpm. The tightening tool according to claim 1 or 2,
A housing that houses the motor and at least a portion of the planetary reducer;
A handle protruding from the housing in a direction intersecting the axis, and configured to be gripped by the user;
A battery removably mounted on a battery mounting portion provided at an end of the handle on the protruding side;
The tightening tool, wherein a center of gravity of the tightening tool when the battery is mounted is located in the handle. The tightening tool according to any one of claims 1 to 3,
An operation member configured to be capable of being pressed by the user;
The tightening tool further comprising: a brake portion configured to stop the rotation of the reaction force receiving member when the pressing operation of the operation member is released. The tightening tool according to any one of claims 1 to 4,
A tightening tool, further comprising an illumination device configured to irradiate light toward a predetermined region including the arm portion. The tightening tool according to any one of claims 1 to 5,
The tightening tool further comprising a torque setting member configured to be able to set the target torque by an external operation of the user. The tightening tool according to any one of claims 1 to 6,
The tightening tool is configured to be operable in a plurality of operation modes including the tightening mode and a loosening mode in which the motor is driven to rotate the socket in a reverse rotation direction to loosen the bolt or the nut. And
The tightening tool, wherein the torque of the first output shaft in the loosening mode is set to be greater than the maximum value of the torque of the first output shaft in the tightening mode.

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