JP2013043262A - Grinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology related to a high-performance torque limiter.SOLUTION: The torque limiter 210 of a grinder has a second bevel gear 211, a spindle 213, a flange 212 to which the torque of the second bevel gear 211 is transmitted, and a ball 214 which moves between a first region to which the torque is transmitted to the flange 212, and a second region which regulates the torque transmitted to the flange 212. In the case that torque of a specified value acts on the spindle 213, the ball 214 is positioned in the first region, and the second bevel gear 211, the flange 212 and the ball 214 rotate integrally, and they transmit torque to the flange 212. In the case that torque not smaller than a specified value acts on the spindle 213, the ball 214 moves from the first region to the second region, and it regulates the torque transmitted from the second bevel gear 211 to the flange 212, thereby regulating the torque acting on the spindle 213.

Description

  The present invention relates to a grinder provided with a torque limiter.

  Japanese Patent Application Laid-Open No. 60-39064 describes an angle grinder provided with a safety clutch for reducing a driving torque when a tool is locked as a torque limiter. This safety clutch is a so-called cam-type torque limiter, and has an overload prevention clutch, a meshing clutch, and a pin for maintaining the meshing clutch in a disengaged state. When the tool is locked, the tooth surfaces of the overload prevention clutch are slid in the opening direction to release the meshing clutch, and the pin is meshed to maintain the disengaged state of the clutch. Thereby, a tool is cut away from a power drive part. Then, when releasing the engagement clutch release state, the user operates the trigger to release the engagement clutch release state by the pin. Thereby, the meshing clutch is meshed again, and the tool is connected to the power drive unit.

JP 60-39064 A

  Incidentally, the torque limiter described in JP-A-60-39064 operates by sliding the teeth of the overload prevention clutch constituting the cam. However, since the cam slides against the frictional force due to meshing, The durability is poor. Further, since the pin is maintained in the disengaged state of the meshing clutch by the pin, the structure for maintaining the disengagement of the meshing clutch is complicated. Furthermore, in order to release the engagement / disengagement state of the meshing clutch, it is necessary for the user to operate the pin, which causes a problem that the operation of the grinder becomes complicated.

  In view of the above, an object of the present invention is to provide a technique related to a higher performance torque limiter.

  In order to solve the above-described problems, according to a preferred embodiment of the grinder according to the present invention, the driven-side rotating member having the driving-side rotating member, the rotating shaft, and the rotational force of the driving-side rotating member is transmitted, and the rotation A torque limiter having a plurality of rolling members that move between a first region in which force is transmitted to the driven-side rotating member and a second region that regulates the rotational force transmitted to the driven-side rotating member; Yes. When a torque less than a predetermined value acts on the rotating shaft, the rolling member is positioned in the first region, and the driving side rotating member, the driven side rotating member, and the rolling member are integrated. It rotates to transmit the rotational force to the driven side rotating member. Further, when a torque greater than or equal to a predetermined value acts on the rotating shaft, the rolling member moves from the first region to the second region to restrict the rotational force transmitted to the driven side rotating member. The “grinder” is a work tool for processing a workpiece by rotating a grindstone such as a polishing tool or a grinding tool, or a tip tool such as a cutting tool. Further, “to restrict the rotational force transmitted to the driven side rotating member” means that the rotational force transmitted to the driven side rotating member is reduced as compared with the case where the rolling member is located in the first region. Or a concept that suitably includes an aspect of blocking.

  According to the present invention, by providing a torque limiter having a rolling member, it is possible to provide a grinder having improved performance such as durability and operability as compared with a grinder provided with a cam type torque limiter. it can.

  According to the further form of the grinder which concerns on this invention, it is provided with the urging member which urges | biases a drive side rotation member and a to-be-driven side rotation member in the mutually approaching direction, and a some rolling member is a drive side rotation member, When a torque greater than or equal to a predetermined value is applied to the rotating shaft, the relative rotation occurs between the driving side rotating member and the driven side rotating member. A configuration in which the rotational force transmitted to the driven-side rotating member is regulated by moving from the first region to the second region while being moved by the relative rotation and being positioned in the second region. Has been.

  According to this embodiment, since the rolling member moves from the first region to the second region while rolling by the relative rotation of the driving side rotating member and the driven side rotating member, the rolling member moves while sliding. Compared to the case, there is less energy loss and the torque limiter can operate smoothly. Further, the wear of the rolling member can be reduced, and the life of the torque limiter, that is, the grinder can be extended.

  According to the further form of the grinder which concerns on this invention, a drive side rotation member is inclined with respect to the 1st groove | channel contacted with a rolling member, the 2nd groove | channel deeper than a 1st groove | channel, and a rotating surface. The drive side inclined surface is provided. The first groove and the second groove are arranged continuously and continuously in the circumferential direction via the drive-side inclined surface. A predetermined portion of the drive side inclined surface constitutes the first region, and a portion other than the first groove, the second groove, and the predetermined portion of the drive side inclined surface constitutes the second region. ing.

  According to this embodiment, at least a part of the driving-side inclined surface forms the first region, and the driving-side rotating member, the rolling member, and the driven-side rotating member are integrated by the urging force of the urging member. The rotational force can be transmitted to the driven side rotation member. And when a rolling member moves to 2nd area | regions other than a 1st area | region, it can move, rolling a drive side slope. Therefore, the torque limiter can be smoothly operated with a simple configuration in which the first groove, the second groove, and the driving-side inclined surface are formed on the driving-side rotating member and the urging force of the urging member is used. .

  According to the further form of the grinder which concerns on this invention, the rotating shaft is comprised so that a front-end tool may be attached, and the drive side rotation member is opposite to the side in which a front-end tool is attached regarding the major axis direction of a rotating shaft. A first groove, a second groove, and a driving side inclined surface are formed on the side.

  According to this embodiment, the driving side rotating member is formed with the first groove, the second groove, and the driving side inclined surface on the surface opposite to the side on which the tip tool is attached with respect to the major axis direction of the rotating shaft. Therefore, the driven side rotating member and the rolling member can be arranged in the space opposite to the side where the tip tool is attached, and the components of the grinder can be rationally arranged.

  According to the further form of the grinder which concerns on this invention, the drive side rotation member is provided with the gear part to which the rotation output of a rotation drive part is transmitted, The gear tooth which comprises a gear part is the long axis of a rotating shaft. It is formed on the surface opposite to the side on which the tip tool is attached with respect to the direction. The “rotation drive unit” is typically a concept that preferably includes a member that outputs a rotational force such as a motor.

  According to this embodiment, the drive side rotation member can also serve as a gear to which the rotation output of the rotation drive unit is transmitted, so that the number of parts used in the grinder can be reduced. Further, the gear portion can be arranged using the space on the side opposite to the side on which the tip tool is attached, and the components of the grinder can be arranged rationally.

  According to the further form of the grinder which concerns on this invention, it has a buffer member arrange | positioned between a drive side rotating member and a driven side rotating member, and a buffer member contact | abuts a 1st groove | channel on a buffer member. Sometimes, it contacts only one of the driving side rotating member and the driven side rotating member, and when the rolling member contacts the second groove, it contacts either the driving side rotating member or the driven side rotating member. It is set as the structure which has thickness.

  According to this embodiment, since the buffer member is provided, when the rolling member moves from the first groove to the second groove, the driving side rolling member and the driven side rolling member move, The impact force generated when stopping can be buffered.

  According to the further form of the grinder which concerns on this invention, The 2nd groove | channel has the structure which has the length of the circumferential direction which controls the free movement of the rotation direction of a rolling member, when a rolling member contact | abuts. Has been.

  The rolling member is positioned in the second groove before the operation of the grinder starts or after the operation ends. At this time, if the rolling member is free to move in the second groove, unnecessary and abrupt torque may be applied to the rotating shaft at the start of the operation or at the end of the operation. According to this embodiment, since the second groove has a circumferential length that restricts the free movement of the rolling member in the rotational direction, it is not necessary for the rotating shaft at the start of the operation or at the end of the operation. The torque limiter can be operated smoothly without applying an urgent torque.

  According to the further form of the grinder which concerns on this invention, an urging | biasing member is the structure which always urges | biases a drive side rotating member and a to-be-driven side rotating member in the mutually approaching direction.

  According to this embodiment, even when the rolling member is located in the second region and restricts the rotational force transmitted to the driven side rotating member, the rolling member is moved by the biasing force of the biasing member. It contacts the driving side rotating member and the driven side rotating member. Therefore, even when the rolling member is located in the second region, the rolling member can move while reliably rolling. Thereby, it can reduce that a rolling member wears. Further, it is possible to prevent the driving side rotating member and the driven side rotating member from being inclined and rotated by the urging force of the urging member.

  According to the further form of the grinder which concerns on this invention, the rotation control member which controls rotation of a rotating shaft is provided.

  According to this form, since rotation of a rotating shaft can be controlled, when attaching a tip tool, it can control that a rotating shaft rotates.

  ADVANTAGE OF THE INVENTION According to this invention, the technique regarding a higher performance torque limiter can be provided.

It is sectional drawing which shows the whole grinder structure concerning embodiment of this invention. It is sectional drawing which shows the torque limiter which concerns on 1st Embodiment of this invention. It is a disassembled perspective view of a torque limiter. It is a fragmentary sectional view along the circumferential direction of the 2nd bevel gear of a torque limiter, and a flange. It is a fragmentary sectional view of the VV line of FIG. It is a fragmentary sectional view along the circumferential direction of the torque limiter which shows operation | movement of a torque limiter. It is sectional drawing which shows the torque limiter which concerns on 2nd Embodiment of this invention. It is a disassembled perspective view of a torque limiter. It is a fragmentary sectional view along the circumferential direction of the 2nd bevel gear of a torque limiter, and a flange. FIG. 6 is a partial cross-sectional view corresponding to FIG. 5 in a second embodiment of the present invention. It is a fragmentary sectional view along the circumferential direction of the torque limiter which shows operation | movement of a torque limiter.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, a grinder will be described as an example of the work tool. The grinder is a work tool that rotates a grindstone such as a grinding tool or a polishing tool, or a cutting tool to perform grinding, polishing, cutting, or the like on a workpiece.

  As shown in FIG. 1, the grinder 1 is mainly composed of a main housing 10, a gear housing 20, a wheel cover 30, and a rear cover 40.

  The main housing 10 is a substantially cylindrical housing and houses the motor 100. The rotation shaft 101 of the motor 100 is disposed so as to protrude toward the gear housing 20.

  The gear housing 20 is provided on one side of the main housing 10, and a first bevel gear 200 externally mounted on the rotating shaft 101 of the motor 100, a torque limiter 210 having a spindle 213 to which the grindstone 2 is attached, and replacement of the grindstone 2. A lock member 270 (see FIG. 5) for restricting the rotation of the spindle 213 is accommodated. This grindstone 2 is an implementation structural example corresponding to the "tip tool" of the present invention.

  The wheel cover 30 is a substantially semicircular component that is detachably attached to the outside of the gear housing 20. The wheel cover 30 is configured to cover the outside of the grindstone 2 attached to the spindle 213 half a circumference, and suppresses scattering of fragments of a workpiece processed by the grindstone 2 and also prevents the user from rotating the grindstone 2. Protect.

  The rear cover 40 is provided on the opposite side of the main housing 10 from the gear housing 20 and accommodates the power supply wiring portion 300. The power supply wiring unit 300 is provided with a power supply cord 301 that supplies current from an external power supply and a switch 302 that switches ON / OFF of the drive of the grinder 1. The power supply wiring unit 300 is electrically connected to the motor 100.

  Next, the torque limiter 210 will be described in detail with reference to FIGS. As shown in FIG. 2, the torque limiter 210 is mainly composed of a second bevel gear 211, a flange 212, a spindle 213, a ball 214, a ball retainer 215, and an urging spring 216.

  As shown in FIGS. 2 and 3, the second bevel gear 211 has a substantially disk shape made of metal, and a recess 220 is formed at the center. A through hole 221 through which the spindle 213 passes is formed at the center of the recess 220. Further, gear teeth are formed on the outer peripheral portion of the recess 220, and constitute a gear portion 222 that meshes with the first bevel gear 200. In FIG. 3, the gear teeth of the gear portion 222 are not shown.

  As shown in FIGS. 3 and 4, the first cam groove 223 and the second cam groove 224 are arranged on the bottom surface of the recess 220 so as to be connected in the circumferential direction via the inclined surfaces 225 a and 225 b. A circle around the through hole 221 is formed. Six second cam grooves 224 are arranged in the circumferential direction. The second cam groove 224 is formed deeper than the first cam groove 223 and shorter than the first cam groove 223 in the circumferential direction. The inclined surface 225 is inclined with respect to the bottom surface of the recess 220. That is, the inclined surface 225 is provided so as to be inclined with respect to the rotating surface of the second bevel gear 211. Note that the arrows in FIG. 4 indicate the rotation direction of the second bevel gear 211. The second bevel gear 211 corresponds to the “drive-side rotating member” of the present invention, and the first cam groove 223, the second cam groove 224, and the inclined surface 225 are the “first groove”, “second” of the present invention, respectively. This is an implementation configuration example corresponding to “groove” and “driving-side inclined surface”.

  The flange 212 has a metal disk shape, and a through hole 230 that engages with the spindle 213 is formed at the center. A third cam groove 231 and a fourth cam groove 232 are connected to the surface of the flange 212 facing the second bevel gear 211 (the lower surface in FIG. 4) in the circumferential direction via the inclined surfaces 233a and 233b. Are arranged to form a circle around the through hole 230. Six fourth cam grooves 232 are arranged in the circumferential direction. Further, the fourth cam groove 232 is formed deeper than the third cam groove 231. The circumferential length of the third cam groove 231 matches the circumferential length of the first cam groove 223, and the circumferential length of the fourth cam groove 232 is the circumferential length of the second cam groove 224. Match the length. Accordingly, the diameter of the circle formed by the third cam groove 231, the fourth cam groove 232, and the inclined surface 233 is the same as that of the first cam groove 223, the second cam groove 224, and the inclined surface 225 formed in the second bevel gear 221. Corresponds to the diameter of the circle formed. The inclined surface 233 is inclined with respect to the surface of the flange 212. That is, the inclined surface 233 is provided so as to be inclined with respect to the rotation surface of the flange 212. The angle of the inclined surface 233 with respect to the rotational surface of the flange 212 is the same as the angle of the inclined surface 225 of the second bevel gear 211 with respect to the rotational surface of the second bevel gear 211. In FIG. 4, for convenience of explanation, only the cross sections of the second bevel gear 211 and the flange 212 are shown, and the illustration of the ball 214, the ball retainer 215, and the like is omitted.

  The spindle 213 has a substantially cylindrical shape, and has a mating groove 280 that mates with the mating pin 234 while being inserted into the through hole 230. The engagement pin 234 is engaged with the engagement groove 280, and the spindle 213 is integrated with the flange 212 (see FIG. 5). The spindle 213 corresponds to the “rotating shaft” of the present invention, and the flange 212 integrated with the spindle 213 is an example of an implementation corresponding to the “driven-side rotating member” of the present invention.

  The balls 214 are made of metal, and six balls 214 are arranged corresponding to the second cam grooves 224. The ball retainer 215 has a disk shape made of resin, and a through hole 240 through which the spindle 213 passes is formed at the center. Around the through hole 240, a ball holding hole 241 for holding the ball 214 is circumferential. Are formed at equal intervals in six places. The six ball holding holes 241 are formed at the same intervals as the second cam grooves 224 corresponding to the second cam grooves 224. This ball 214 is an implementation configuration example corresponding to the “rolling member” of the present invention.

  The urging spring 216 has a configuration in which two sets of disc springs 250 arranged in different directions with the plain washer 251 in between are connected to each other. The number of the disc springs 250 can be changed as appropriate according to the required biasing force. This urging spring 216 is an implementation configuration example corresponding to the “urging member” of the present invention.

  As shown in FIG. 2, the second bevel gear 211, the flange 212, the spindle 213, the ball 214, the ball retainer 215, and the urging spring 216 are assembled to constitute a torque limiter 210. The second bevel gear 211 and the ball retainer 215 are assembled to be rotatable relative to the spindle 213, and the flange 212 and the biasing spring 216 rotate integrally with the spindle 213. The ball 214 is movable along the first cam groove 223, the second cam groove 224, and the inclined surface 225 of the second bevel gear 211, and similarly, the third cam groove 231 and the fourth cam groove of the flange 212. 232 and movable along the inclined surface 233. A nut 252 is screwed onto the end of the spindle 213, and the biasing force of the biasing spring 216 can be adjusted by adjusting the position of the nut 252. This urging force urges the flange 212 and the second bevel gear 211 in a direction to approach each other.

  As shown in FIGS. 1 and 2, the torque limiter 210 is held on the gear housing 20 by two ball bearings 260 such that one end of the spindle 213 protrudes from the gear housing 20. Thus, the torque limiter 210 is disposed in the gear housing 20 so that the major axis direction of the spindle 213 and the rotation axis 101 of the motor 100 are orthogonal to each other.

  As shown in FIG. 1, an inner flange 281 and an outer flange 282 are attached to the tip of the spindle 213. The outer flange 282 is screwed with the spindle 213 and sandwiches the grindstone 2 between the inner flange 281 and the outer flange 282.

  As described above, the grinder 1 is provided with the torque limiter 210, so that the first cam groove 223, the second cam groove 224, and the inclined surface 225 are in the second bevel gear 211 with respect to the major axis direction of the spindle 213. 2 is formed on the side opposite to the side to which it is attached. Similarly, the gear part 222 is also formed in the second bevel gear 211 on the side opposite to the side on which the grindstone 2 is attached.

  Next, the lock member 270 will be described with reference to FIG. The lock member 270 is mainly configured by a lock pin 271, a pressing cap 272, and a coil spring 273. The lock pin 271 is disposed through the gear housing 20 in parallel with the long axis direction of the spindle 213. The lock pin 271 is provided with a hook-shaped drop prevention portion 274 to prevent the lock pin 271 from coming out of the gear housing 20. The distal end of the lock pin 271 is configured to engage with an engagement recess 235 provided in the flange 212 of the torque limiter 210.

  The pressing cap 272 is coupled to the other end of the lock pin 271 outside the gear housing 20. The coil spring 273 is externally mounted on the lock pin 271 outside the gear housing 20, and one end engages with the pressing cap 272 and the other end engages with the concave coil spring engaging portion 21 provided outside the gear housing 20. Match.

  The lock member 270 is urged outward from the gear housing 20 by the urging force of the coil spring 273, and the drop prevention portion 274 contacts the gear housing 20 to prevent the lock member 270 from coming off. Yes. At this time, the tip of the lock pin 271 is located away from the engagement recess 235 of the flange 212.

  When the lock member 270 is pushed against the urging force of the coil spring 273, the lock pin 271 moves in a direction approaching the flange 212, and the tip of the lock pin 271 engages with the engagement recess 235. This restricts the circumferential movement of the flange 212 and restricts the spindle 213 from rotating when the grindstone 2 is replaced. This lock member 270 is an implementation configuration example corresponding to the “rotation restricting member” of the present invention.

  The grinder 1 configured as described above is supplied with electric power from the external power supply to the motor 100 via the electric wiring unit 300 when the switch 302 is operated. As a result, the motor 100 is driven to rotate, and the first bevel gear 200 attached to the rotating shaft 101 rotates. When the first bevel gear 200 and the second bevel gear 211 are screwed together and rotated, the rotational output of the motor 100 is converted into a rotational force around the spindle 213, and the grindstone 2 mounted on the spindle 213 is rotated. The workpiece can be processed by pressing the rotating grindstone 2 against the workpiece.

  Next, the operation of the torque limiter 210 will be described with reference to FIG. In FIG. 6, for convenience of explanation, only the second bevel gear 211, the flange 212, the ball 214, and the ball retainer 215 of the torque limiter 210 are illustrated, and the urging spring 216 and the like are not illustrated. . Although only one ball 214 will be described, the movement of the other balls 214 is the same. In addition, an arrow A in FIGS. 6B to 6F indicates the rotation direction of the second bevel gear 211, and an arrow B in FIGS. It shows the rotation when moving.

  FIG. 6A shows the state of the torque limiter 210 when the grinder 1 is not driven. At this time, the ball 214 is in contact with the second cam groove 224 a, and the ball retainer 215 is in contact with both the second bevel gear 211 and the flange 212. In other words, the ball retainer 215 is configured to have a thickness that abuts both the second bevel gear 211 and the flange 212 when the ball 214 abuts on the second cam groove 224 when not driven. Thus, when the ball 214 is in contact with the second cam groove 224, the upper portion of the ball 214 is not in contact with the fourth cam groove 232a. The second cam groove 224 has a length that restricts the free movement of the ball 214 in the rotation direction of the second cam groove 224 when the grinder 1 is not driven.

  FIG. 6B shows a state in which the rotation output of the motor 100 is transmitted to the spindle 213. The rotation output of the motor 100 is transmitted to the second bevel gear 211, and the second bevel gear 211 rotates in the direction of arrow A. The rotation of the second bevel gear 211 moves the ball 214 to a position where it comes into contact with the inclined surface 225a of the second bevel gear 211 and the inclined surface 233a of the flange 212, which are arranged in parallel. At this time, the urging force of the urging spring 216 causes the second bevel gear 211, the ball 214, and the flange 212 to rotate together, whereby the rotational force of the second bevel gear 211 is transmitted to the spindle 213. Then, the grindstone 2 attached to the spindle 213 is rotated to process the workpiece. At this time, each portion of the inclined surface 225a with which the ball 214 abuts corresponds to the “first region” of the present invention.

  FIG. 6C shows a state in which the rotational force transmitted from the second bevel gear 211 to the flange 212 is restricted when a torque greater than a predetermined value is applied to the spindle 213 while the grinder 1 is being driven. ing. For example, in FIG. 6B, when the grindstone 2 bites into the workpiece while machining the workpiece, the rotation of the grindstone 2 is hindered. Accordingly, the spindle 213 to which the grindstone 2 is attached and the flange 212 engaged with the spindle 213 also stop rotating. On the other hand, since the motor 100 continues to be driven, the rotation output of the motor 100 is transmitted to the second bevel gear 211. When the rotational force of the second bevel gear 211 is transmitted to the flange 212, a torque greater than or equal to a predetermined value may act on the spindle 213 between the grindstone 2 and the flange 212 that is prevented from rotating.

  Therefore, in the present embodiment, the flange 212 stops rotating, but the second bevel gear 211 continues to rotate, thereby causing relative rotation between the second bevel gear 211 and the flange 212. Due to this relative rotation, a force to roll is generated on the ball 214 sandwiched between the second bevel gear 211 and the flange 212 from above and below. When the sum of the force components in the direction parallel to the spindle 213 of the force to roll in the six balls 214 exceeds the biasing force of the biasing spring 216, the ball 214 in contact with the inclined surfaces 225a and 233a It rolls while pushing up 212 and moves to a position where it abuts against the first cam groove 223 and the third cam groove 231. As described above, the ball 214 is positioned in the first cam groove 223 parallel to the rotation surface, thereby restricting the rotational force transmitted from the second bevel gear 211 to the flange 212, thereby acting on the spindle 213. The torque to be controlled is regulated. The ball 214 moves to a position where it comes into contact with the first cam groove 223 and the third cam groove 231, so that a gap t is generated between the flange 212 and the ball retainer 215.

  FIG. 6D and FIG. 6E show the behavior after the ball 214 moves to a position where it comes into contact with the first cam groove 223 and the third cam groove 231 in FIG. 6C. By the relative rotation of the second bevel gear 211 and the flange 212, the ball 214 moves while rolling from the second cam groove 224a toward the second cam groove 224b adjacent to the second cam groove 224a in the circumferential direction. At this time, on the flange 212, the ball 214 moves from the fourth cam groove 232a toward the fourth cam groove 232b adjacent to the fourth cam groove 232a in the circumferential direction. 6C to 6E, the biasing force of the biasing spring 216 is transmitted from the flange 212 to the second bevel gear 211 via the ball 214. That is, the urging spring 216 constantly urges the second bevel gear 211 and the flange 212 in a direction approaching each other.

  FIG. 6F shows that when the ball 214 moves from the first cam groove 223 to the second cam groove 224b and from the third cam groove 231 to the fourth cam groove 232b, the ball 214 comes into contact with the inclined surfaces 225b and 233b. It shows the state. During the movement of the ball 214 to the second cam groove 224b and the fourth cam groove 232b, the flange 212 receiving the urging force from the urging spring 216 approaches the second bevel gear 211 so that the gap t becomes smaller, Again contact the ball retainer 215. Thereafter, the ball 214 contacts the inclined surfaces 225a and 233a via the second cam groove 224b and returns to the state shown in FIG. 6B, and repeats the same movement.

  In each of FIGS. 6C to 6F, the rotational force of the second bevel gear 211 is not transmitted to the flange 212. In this state, the first cam groove 223, the second cam groove 224, and the inclined surface 225b of the second bevel gear 221 with which the ball 214 abuts correspond to the “second region” of the present invention.

  According to the first embodiment described above, the ball 214 moves while rolling by the relative rotation of the second bevel gear 211 and the flange 212, so that the ball 214 can move smoothly. Thereby, the torque limiter 210 can be operated smoothly. In addition, the wear and heat generation of the ball 214 due to friction can be reduced compared to the case where the ball 214 moves while sliding against the frictional force.

  Further, according to the first embodiment, the second bevel gear 211, the flange 212, and the ball 214 rotate integrally by the ball 214 coming into contact with the inclined surfaces 225 a and 233 a and receiving a biasing force from the biasing spring 216. can do. Therefore, the torque limiter 210 can be smoothly operated with a simple configuration in which grooves are formed in the second bevel gear 211 and the flange 212.

  Further, according to the first embodiment, the urging spring 216 constantly urges the second bevel gear 211 and the flange 212 in directions close to each other. Therefore, even when the rotation of the second bevel gear 211 is not transmitted to the flange 212, the second bevel gear 211 can be prevented from rotating with an inclination with respect to the spindle 213.

  Further, according to the first embodiment, since the ball retainer 215 has the ball holding hole 241 for holding the ball 214, the ball 214 is spaced at the same interval as the interval between the second cam groove 224 and the fourth cam groove 232. Can be held in. In other words, the ball retainer 215 has a function of holding the gap between the balls 214.

  If the ball retainer 215 is not provided, the second bevel gear is moved when the ball 214 moves from the first cam groove 223 and the third cam groove 231 to the second cam groove 224 and the fourth cam groove 232. When 211 and the flange 212 move in the direction in which they approach, both the second bevel gear 211 and the flange 212 collide with the ball 214. Due to the collision between these metal members, abnormal noise or metal fatigue occurs during operation of the torque limiter 1. However, in the present embodiment, when the ball 214 is positioned in the second cam groove 224, the ball retainer 215 having a thickness that contacts both the second bevel gear 211 and the flange 212 is disposed. Prevents second bevel gear 211 and flange 212 from colliding with ball 214 when 214 moves from first cam groove 223 and third cam groove 231 to second cam groove 224 and fourth cam groove 232 it can. Further, the second bevel gear 211 and the flange 212 are prevented from directly colliding with each other at the outer edge portion of the flange 212. Further, since the ball retainer 215 is made of resin, the impact force of the metal second bevel gear 211 and the flange 212 colliding with the ball retainer 215 can be buffered. That is, the ball retainer 215 also has a function as a buffer member.

  According to the first embodiment, the circumferential length of the second cam groove 224 is such that the ball 214 restricts free movement in the rotational direction of the second cam groove 224 when the grinder 1 is not driven. It has become. If the free movement of the ball 214 in the rotational direction of the second cam groove 224 is not restricted, the second bevel gear 211 and the flange 212 are moved by the movement of the ball 214 when the grinder 1 is driven or stopped. A rotation difference will occur. Due to this difference in rotation, there is a possibility that an unnecessary and abrupt torque is applied to the spindle 213 when the grinder 1 is started or stopped, or that the torque limiter 1 malfunctions. In this embodiment, when the grinder 1 is not driven, the ball 214 has a length that restricts the free movement of the second cam groove 224 in the rotation direction. There is no fear that the torque limiter 1 will malfunction.

  Further, according to the first embodiment, in the second bevel gear 211, the first cam groove 223, the second cam groove 224, and the inclined surface 225 are provided on the side opposite to the side on which the grindstone 2 is attached in the major axis direction of the spindle 213. Is formed. Therefore, the second bevel gear can be obtained by disposing the components such as the flange 212, the ball 214, and the ball retainer 215 disposed on the same side as the first cam groove 223, the second cam groove 224, and the inclined surface 225 in the recess 220. 211 can be disposed on the opposite side of the grindstone 2. Thereby, the length of the part which protrudes in the direction in which the grindstone 2 is attached from the 2nd bevel gear 211 of the spindle 213 can be shortened, and the grinder 1 can be reduced in size. Furthermore, a gear tooth is formed at the peripheral edge of the second bevel gear 211, so that a recess 220 is formed at the center of the second bevel gear 211. By arranging components such as the flange 212, the ball 214, and the ball retainer 215 in the recess 220, the torque limiter 210 can be downsized by rationally arranging the components. Thereby, the grinder 1 can be reduced in size.

  Further, according to the first embodiment, in the second bevel gear 211, the gear portion 222 is formed on the side opposite to the side on which the grindstone 2 is attached in the major axis direction of the spindle 213. Therefore, the length of the portion protruding from the second bevel gear 211 of the spindle 213 can be shortened, and the grinder 1 can be reduced in size. Further, the torque limiter 210 is configured by forming the gear portion 222, the first cam groove 223, the second cam groove 224, and the inclined surface 225 on the opposite side of the second bevel gear 211 to the side on which the grindstone 2 is attached. Can be reasonably arranged. Thereby, the grinder 1 can be further reduced in size.

  In the first embodiment, the ball retainer 215 is formed with the ball retaining hole 241 for retaining the interval between the balls 214, and the ball retainer 215 serves as both the interval retaining member and the buffer material. A cushioning material may be provided separately from the ball retainer 215 that functions as a spacing member.

(Second Embodiment)
Next, a second embodiment will be described. However, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  FIG. 7 shows a torque limiter 1210 according to the second embodiment. The configuration of the grinder 1 other than the torque limiter 1210 is the same as that of the first embodiment. The torque limiter 1210 mainly includes a second bevel gear 1211, a rotation transmission member 1212a, a pressing force transmission member 1212b, a spindle 1213, a ball 1214, a shock absorber 1215, a biasing spring 1216, a support ball 1217, and a thrust bearing 1218. ing.

  As shown in FIGS. 7 and 8, the second bevel gear 1211 is similar to the second bevel gear 211 of the first embodiment in that the bottom surface of the recess 1220 has a through hole 1221, a first cam groove 1223, and a second cam groove. 1224 and the inclined surface 1225 are formed in a circumferential shape, and a support groove 1226 in which the support ball 1217 moves is further formed outside the circumference. A gear portion 1222 in which gear teeth are formed is formed outside the recess 1220. In FIG. 8, the gear teeth are not shown.

  As shown in FIG. 9, the first cam groove 1223 and the second cam groove 1224 are arranged so as to be connected in the circumferential direction via an inclined surface 1225. Note that the arrows in FIG. 9 indicate the rotation direction of the second bevel gear 1211. Further, in FIG. 9, for convenience of explanation, only the cross sections of the second bevel gear 1211 and the pressing force transmission member 1212b are illustrated, and the rotation transmission member 1212a, the ball 1214, and the like are not illustrated. The second bevel gear 1211 corresponds to the “drive-side rotating member” of the present invention, and the first cam groove 1223, the second cam groove 1224, and the inclined surface 1225 are the “first groove”, “second” of the present invention, respectively. This is an implementation configuration example corresponding to “groove” and “driving-side inclined surface”.

  As shown in FIGS. 7 and 8, the rotation transmitting member 1212a and the pressing force transmitting member 1212b are in the shape of a metal disk, and through holes 1230a and 1230b through which the spindle 1213 passes are formed in the center. The buffer body 1215 has a disk shape made of resin, and a through hole 1240 through which the spindle 1213 passes is formed at the center.

  In the rotation transmitting member 1212a, a buffer material holding portion 1236 is formed around the through hole 1230a. In addition, three engagement recesses 1235 that engage with the lock pins 271 (see FIG. 10) are formed in the outer peripheral portion. The buffer material holding portion 1236 is formed with six ball holding holes 1241 having a size corresponding to the ball 1214. In the pressing force transmission member 1212b, a third cam groove 1231 is formed in a circumferential direction on a surface facing the second bevel gear 1211 (a lower surface in FIG. 9). In the second embodiment, only the third cam groove 1231 is provided, and no inclined surface is provided.

  The spindle 1213 has a substantially cylindrical shape, and is formed with a mating groove 1280 that mates with the mating convex portion 1237 of the through hole 1230a while being inserted into the through holes 1230a, 1240, and 1230b. The spindle 1213 corresponds to the “rotating shaft” of the present invention, and the rotation transmitting member 1212a and the pressing force transmitting member 1212b integrated with the spindle 1213 correspond to the “driven-side rotating member” of the present invention. It is an example.

  The balls 1214 are made of metal, and six balls 1214 are arranged corresponding to the second cam grooves 1224. The support balls 1217 are made of metal, and four support balls 1217 are arranged in the support grooves 1226. This ball 1214 is an implementation configuration example corresponding to the “rolling member” of the present invention.

  The urging spring 1216 has a configuration in which a pair of disc springs 1250 are arranged with their plain washer 1251 sandwiched between them. In the first embodiment, two sets of disc springs 250 are provided, but in the second embodiment, one disc spring 1250 is provided, and the number of disc springs is appropriately determined according to the required biasing force. It is possible to change. This urging spring 1216 is an implementation configuration example corresponding to the “urging member” of the present invention.

  As shown in FIG. 7, the second bevel gear 1211, the rotation transmission member 1212a, the pressing force transmission member 1212b, the spindle 1213, the ball 1214, the shock absorber 1215, the urging spring 1216, the support ball 1217, and the thrust bearing 1218 The torque limiter 1210 is configured by being assembled. The second bevel gear 1211, the pressing force transmission member 1212 b, the buffer body 1215, the urging spring 1216, and the thrust bearing 1218 are assembled so as to be rotatable relative to the spindle 1213, and the rotation transmission member 1212 a is integrated with the spindle 1213. Rotate to. In addition, the ball 1214 is movable along the first cam groove 1223, the second cam groove 1224, and the inclined surface 1225 of the second bevel gear 1211. In addition, the support ball 1217 is movable along the support groove 1226 of the second bevel gear 1211.

  A nut 1252 is attached to the end of the spindle 1213, and the biasing force by the biasing spring 1216 can be adjusted by adjusting the position of the nut 1252. This urging force is transmitted to the pressing force transmission member 1212b via the thrust bearing 1218, and urges the pressing force transmission member 1212b and the second bevel gear 1211 in a direction to approach each other.

  At this time, the support ball 1217 supports the outer periphery of the rotation transmission member 1212 a, thereby maintaining a predetermined gap between the rotation transmission member 1212 a and the second bevel gear 1211, and the rotation transmission member 1212 a with respect to the spindle 1213. Suppresses tilting. In the present embodiment, four support balls 1217 are arranged, but three or more constituting a plane may be arranged.

  Next, the lock member 270 will be described. As shown in FIG. 10, the distal end of the lock pin 271 is disposed away from the engagement recess 1235 of the rotation transmitting member 1212a. When the lock member 270 is pushed against the urging force of the coil spring 273, the lock pin 271 moves in a direction approaching the rotation transmitting member 1212a, and the tip engages with the engagement recess 1235. Thereby, the movement of the rotation transmitting member 1212a in the circumferential direction is restricted, and the spindle 1213 is restricted from rotating when the grindstone 2 is replaced. This lock member 270 is an implementation configuration example corresponding to the “rotation regulating member” of the present invention.

  Next, the operation of the torque limiter 1210 will be described with reference to FIG. In FIG. 11, for convenience of explanation, only the second bevel gear 1211, the rotation transmission member 1212a, the pressing force transmission member 1212b, and the ball 1214 of the torque limiter 1210 are illustrated, and the biasing spring 1216 and the like are illustrated. Omitted. Although only one ball 1214 will be described, the movement of the other balls 1214 is the same. Moreover, the arrow in FIG.11 (b)-FIG.11 (f) has shown the rotation direction of the 2nd bevel gear 1211, and the arrow 12B in FIG.11 (c)-FIG.11 (f) moves the ball | bowl 1214. FIG. It shows the rotation when you do.

  FIG. 11A shows a state of the torque limiter 1210 when the grinder 1 is not driven. At this time, the ball 1214 is positioned in the second cam groove 1224a, and the upper portion of the ball 1214 is not in contact with the third cam groove 1231 of the pressing force transmission member 1212b. At this time, as shown in FIG. 7, the urging spring 1216 presses the pressing member 1212 b via the thrust bearing 1218, the pressing force transmitting member 1212 b and the upper surface of the buffer 1215 come into contact with each other, and the buffer 1215 The lower surface and the rotation transmitting member 1212a are in contact with each other. The rotation transmitting member 1212a is supported by the support ball 1217 and is not in contact with the second bevel gear 1211. The second cam groove 1224 has a length that restricts the free movement of the ball 1214 in the rotation direction of the second cam groove 1224 when the grinder 1 is not driven.

  FIG. 11B shows a state where the rotation output of the motor 100 is transmitted to the spindle 1213. The rotation output of the motor 100 is transmitted to the second bevel gear 1211, and the second bevel gear 1211 rotates in the direction of the arrow. Due to the rotation of the second bevel gear 1211, the ball 1214 moves to the inclined surface 1225a of the second bevel gear 1211 and abuts against the third cam groove 1231 of the pressing force transmission member 1212b, and the ball holding hole of the rotation transmission member 1212a. It abuts against the wall surface 1241a of 1241. At this time, the urging force of the urging spring 1216 is transmitted to the ball 1214 via the pressing force transmitting member 1212b, so that the ball 1214 is sandwiched between the inclined surface 1225a and the wall surface 1241a, and the second bevel gear 1211 The rotational force is transmitted to the rotation transmission member 1212a. That is, the second bevel gear 1211, the ball 1214, and the rotation transmission member 1212a rotate as a unit. As a result, the rotational force of the second bevel gear 1211 is transmitted to the spindle 1213. Then, the grindstone 2 attached to the spindle 1213 is rotated to process the workpiece. At this time, the portion of the inclined surface 1225a with which the ball 1214 comes into contact corresponds to the “first region” of the present invention.

  FIG. 11C shows a state in which the rotational force transmitted from the second bevel gear 1211 to the spindle 1213 is restricted when a torque greater than a predetermined value is applied to the spindle 1213 while the grinder 1 is being driven. ing. In the present embodiment, when a torque of a predetermined value or more acts on the spindle 1213, the second bevel gear 1211 continues to rotate, but the rotation transmitting member 1212a stops rotating. As a result, a force pressing the ball 1214 from the rotation transmitting member 1212a acts on the ball 1214. When this pressing force is applied, the ball 1214 receives a reaction force from the inclined surface 1225a. When the sum of the force components of the six balls 1214 in the direction parallel to the spindle 1213 exceeds the urging force of the urging spring 1216, the ball 1214 in contact with the inclined surface 1225a causes the pressing force transmitting member 1212 to move. It moves to the 1st cam groove 1223, pushing up. At this time, the pressing force transmission member 1212b is urged via the thrust bearing 1218 and is not fixed in the rotation direction and can freely rotate. Therefore, the ball 1212 moves to the first cam groove 1223 while rolling. be able to. That is, the relative rotation between the second bevel gear 1211 and the pressing force transmission member 1212b causes the ball 1214 to move from the inclined surface 1225a to the first cam groove 1223 while rolling. As described above, the ball 1214 is positioned in the first cam groove 1223 parallel to the rotation surface, thereby restricting the rotational force transmitted from the second bevel gear 1211 to the rotation transmission member 1212a. The torque which acts on is controlled. The pressing force transmission member 1212b is pushed up by the ball 1214, so that a gap is generated between the pressing force transmitting member 1212b and the upper surface of the buffer body 1215.

  FIG. 11D and FIG. 11E show the behavior after the ball 1214 has moved to a position where it abuts against the first cam groove 1223 and the third cam groove 1231 in FIG. 11C. By the rotation of the second bevel gear 1211, the ball 1214 moves while rolling from the second cam groove 1224a toward the second cam groove 1224b adjacent to the second cam groove 1224a in the circumferential direction. 11C to 11E, the urging force of the urging spring 1216 is transmitted from the pressing member 1212b to the second bevel gear 1211 via the ball 1214. That is, the urging spring 1216 constantly urges the second bevel gear 1211 and the pressing member 1212b in a direction approaching each other.

  FIG. 11F shows a state in which the ball 1214 is in contact with the inclined surface 1225b when moving from the first cam groove 1223 to the second cam groove 1224b. In the middle of the movement of the ball 1214 to the second cam groove 1224b, the pressing force transmission member 1212b receiving the urging force from the urging spring 1216 abuts against the buffer 1215 again. Thereafter, the ball 1214 comes into contact with the inclined surface 1225a through the second cam groove 1224b and returns to the state shown in FIG. 11B, and repeats the same movement.

  11C to 11F, the rotational force of the second bevel gear 1211 is not transmitted to the rotation transmitting member 1212a. In this state, the first cam groove 1223, the second cam groove 1224, and the inclined surface 1225b of the second bevel gear 1211 with which the ball 1214 abuts correspond to the “second region” of the present invention.

  According to the second embodiment described above, by providing the thrust bearing 1218, the pressing force transmission member 1212b that receives the biasing force from the biasing spring 1216 can be freely rotated, and the second bevel gear 1211 and the pressing force transmission member 1212b can be rotated. Relative rotation can occur.

  Further, according to the second embodiment, the ball 1214 can move smoothly because the ball 1214 moves while rolling by the relative rotation of the second bevel gear 1211 and the pressing force transmission member 1212b. Thereby, the torque limiter 1210 can be operated smoothly. Further, compared to the case where the ball 1214 moves while sliding against the frictional force, wear of the ball 1214 and heat generation due to friction can be reduced.

  Further, according to the second embodiment, the urging spring 1216 constantly urges the second bevel gear 1211 and the pressing force transmission member 1212b toward each other. Therefore, even when the rotation of the second bevel gear 1211 is not transmitted to the rotation transmitting member 1212a, the second bevel gear 1211 can be prevented from rotating at an angle with respect to the spindle 1213.

  According to the second embodiment, the circumferential length of the second cam groove 1224 is such that the ball 1214 restricts free movement of the second cam groove 1224 in the rotational direction when the grinder 1 is not driven. It has become. Assuming that the free movement of the ball 1214 in the rotation direction of the second cam groove 1224 is not restricted, the second bevel gear 1211 and the flange 1212 are moved by the movement of the ball 1214 when the grinder 1 is driven or stopped. A rotation difference will occur. Due to this rotational difference, there is a possibility that an unnecessary and abrupt torque is applied to the spindle 1213 when the grinder 1 is started or stopped, or that the torque limiter 1 malfunctions. In the present embodiment, when the grinder 1 is not driven, the ball 1214 has a length that restricts the free movement of the second cam groove 1224 in the rotation direction. There is no fear that the torque limiter 1 will malfunction.

  Further, according to the second embodiment, since the rotation transmission member 1212a is provided with the ball holding hole 1241 for holding the ball 1214, the rotation transmission member 1212a transmits the rotational force of the second bevel gear 1211 to the spindle 1213. And a function of maintaining the distance between the balls 1214. Thereby, it is not necessary to provide a special spacing member for holding the ball 1214, and the number of parts of the torque limiter 1210 can be reduced.

  Further, according to the second embodiment, since the buffer 1215 is made of resin, it is possible to buffer the impact force that the rotation transmission member 1212a and the pressing force transmission member 1212b collide with the buffer 1215. Further, when the ball 1214 is positioned in the second cam groove 1224b, the ball 1214 is not in contact with the pressing force transmission member 1212b provided with the third cam groove 1231. Therefore, the ball 1214 passes through the ball 1214 from the pressing force transmission member 1212b. Thus, transmission of impact force to the second bevel gear 1211 can be suppressed.

  Further, according to the second embodiment, in the second bevel gear 1211, the first cam groove 1223, the second cam groove 1224, and the inclined surface 1225 are provided on the side opposite to the side on which the grindstone 2 is attached in the major axis direction of the spindle 1213. Is formed. Therefore, components such as the first cam groove 1223, the second cam groove 1224, and the rotation transmission member 1212a, the pressing force transmission member 1212b, the ball 1214, and the shock absorber 1215 disposed on the same side as the inclined surface 1225 are replaced with the second bevel gear 1211. However, it can be arranged on the opposite side of the grindstone 2. Thereby, the length of the part which protrudes in the direction in which the grindstone 2 is attached from the 2nd bevel gear 1211 of the spindle 1213 can be shortened, and the grinder 1 can be reduced in size. Further, a gear tooth is formed on the peripheral edge of the second bevel gear 1211, whereby a recess 1220 is formed in the central portion of the second bevel gear 1211. By disposing components such as the rotation transmission member 1212a, the pressing force transmission member 1212b, the ball 1214, and the shock absorber 1215 in the recess 1220, the torque limiter 1210 can be downsized by rationally arranging the components. Thereby, the grinder 1 can be reduced in size.

  Further, according to the second embodiment, in the second bevel gear 1211, the gear portion 1222 is formed on the side opposite to the side on which the grindstone 2 is attached in the major axis direction of the spindle 1213. Therefore, the length of the portion protruding from the second bevel gear 1211 of the spindle 1213 can be shortened, and the grinder 1 can be reduced in size. Further, the torque limiter 1210 is configured by forming the gear portion 1222, the first cam groove 1223, the second cam groove 1224, and the inclined surface 1225 on the opposite side of the second bevel gear 1211 to the side on which the grindstone 2 is attached. Can be reasonably arranged. Thereby, the grinder 1 can be further reduced in size.

  In the second embodiment described above, the inclined surface 1225 that is inclined with respect to the rotational surface of the second bevel gear 1211 is formed on the second bevel gear 1211. However, the present invention is not limited to this. For example, when the difference in depth between the first cam groove 1223 and the second cam groove 1224 is shorter than the radius than the ball 1214, the inclined surface 1225 may be an intersecting surface orthogonal to the rotation surface. .

  In the above embodiment, the urging springs 216 and 1216 always urge the flange 212 or the pressing force transmission member 1212b, but at least the second bevel gears 211 and 1211 are applied to the flange 212 or the pressing force transmission member 1212b. When transmitting the rotational force, it is only necessary to apply an urging force.

  In the above embodiment, the second bevel gears 211 and 1211 are engaged with the first bevel gear 200 and the rotational force of the motor 100 is transmitted. A rotation member other than the above may be provided, and the rotation force of the second bevel gear may be transmitted to the rotation member.

  In the above embodiment, the circumferential length of the second cam grooves 224 and 1224 is such that the balls 214 and 1214 are free in the rotational direction of the second cam grooves 224 and 1224 when the grinder 1 is not driven. Although the length is restricted to restrict movement, the length is not limited to restricting free movement of the balls 214 and 1214.

  In the above embodiment, the inclined surfaces 225, 1225, and 233 are inclined surfaces that are inclined with respect to the rotation surfaces of the second bevel gears 211 and 1211, and the flange 212. It is not restricted to the inclined surface formed with respect to a fixed angle with respect to it, The circular arc surface formed in circular arc shape may be sufficient. Moreover, the some inclined surface which has mutually different angle with respect to a rotating surface may be comprised, and it may be comprised.

  In the above embodiment, torque limiters 210 and 1210 each having six balls 214 and 1214 have been described. However, the number of balls is not limited to six, and three or more that can form a plane. If it is. The rolling member is not limited to a ball, and may be a member such as a roller having a columnar shape, a conical shape, a truncated cone shape, or the like.

  In the above embodiment, for the sake of convenience of explanation, the second bevel gears 211 and 1211 are positioned below the gravitational direction with the major axis direction of the spindles 213 and 1213 aligned with the gravitational direction. The positions of the balls 214 and 1214 may be different depending on the mode of using the. For example, in a mode in which the grinder 1 is used by reversing the vertical direction of the spindles 213 and 1213, the balls 214 and 1214 do not contact the second bevel gears 211 and 1211 when the grinder 1 is not driven. That is, the contact relationship between the balls 214 and 1214 and other members, and the contact relationship between the ball retainer 215 and the buffer body 1215 and other members, according to the gravity direction and the usage mode of the grinder 1, are as described above. It may change from the description. .

  In the above embodiment, the grinder in which the major axis direction of the spindle 213 and the rotation shaft 101 of the motor 100 are orthogonal to each other has been described. However, the present invention is not limited to an aspect in which these axes are orthogonally arranged.

  In the above embodiment, the grinder having the torque limiter has been described. However, the torque limiter of the present invention can also be applied to a work tool that performs rotational driving other than the grinder, such as a hammer drill or a circular saw.

1 Grinder 2 Grinding wheel (tip tool)
DESCRIPTION OF SYMBOLS 10 Main housing 20 Gear housing 21 Coil spring engaging part 30 Wheel cover 40 Rear cover 100 Motor 101 Rotating shaft 200 First bevel gear 210 Torque limiter 211 Second bevel gear (drive side rotating member)
212 Flange (driven side rotating member)
213 Spindle (driven side rotating member, rotating shaft)
214 Ball (rolling member)
215 Ball retainer (buffer member)
216 Biasing spring (biasing member)
220 Concave portion 221 Through hole 222 Gear portion 223 First cam groove (first groove)
224 Second cam groove (second groove)
225 Inclined surface (Drive-side inclined surface)
230 Through hole 231 Third cam groove 232 Fourth cam groove 233 Inclined surface 234 Engagement pin 235 Engaging recess 240 Through hole 241 Ball holding hole 250 Belle spring 251 Plain washer 252 Nut 260 Ball bearing 270 Lock member (rotation restricting member)
280 Joint groove 281 Inner flange 282 Outer flange 300 Electric wiring part 1210 Torque limiter 1211 Second bevel gear (drive-side rotating member)
1212a Rotation transmission member (driven side rotation member)
1212b Pressing force transmission member (driven side rotating member)
1213 Spindle (driven side rotating member, rotating shaft)
1214 ball (rolling member)
1215 shock absorber 1216 biasing spring (biasing member)
1217 Support ball 1218 Thrust bearing 1223 First cam groove (first groove)
1224 Second cam groove (second groove)
1225 Inclined surface (Drive-side inclined surface)
1226 Support groove 1231 Third cam groove

Claims (9)

A driving side rotating member;
A driven-side rotating member having a rotating shaft and to which the rotational force of the driving-side rotating member is transmitted;
Torque having a plurality of rolling members that move between a first region where the rotational force is transmitted to the driven-side rotating member and a second region that regulates the rotational force transmitted to the driven-side rotating member A grinder with a limiter,
When a torque less than a predetermined value acts on the rotating shaft, the rolling member is located in the first region, and the driving side rotating member, the driven side rotating member, and the rolling member are Rotate together to transmit the rotational force to the driven side rotating member,
When the torque greater than the predetermined value is applied to the rotation shaft, the rolling member moves from the first region to the second region and is transmitted to the driven side rotation member. A grinder characterized in that it is configured to regulate. A grinder according to claim 1,
An urging member that urges the driving side rotating member and the driven side rotating member in a direction approaching each other;
The plurality of rolling members are disposed between the driving side rotating member and the driven side rotating member,
When a torque greater than the predetermined value acts on the rotating shaft, relative rotation occurs between the driving side rotating member and the driven side rotating member, and the rolling member rolls due to the relative rotation. However, the rotational force transmitted to the driven side rotation member is regulated by moving from the first region to the second region and being positioned in the second region. And grinder. A grinder according to claim 2,
The driving-side rotating member has a first groove that contacts the rolling member, a second groove deeper than the first groove, and a driving-side inclined surface that is inclined with respect to the rotating surface. The first groove and the second groove are arranged continuously and continuously in the circumferential direction via the drive-side inclined surface,
A predetermined portion of the drive-side inclined surface constitutes the first region, and a portion other than the predetermined portion of the first groove, the second groove, and the drive-side inclined surface is the second region. A grinder characterized by comprising a region of A grinder according to claim 3,
The rotating shaft is configured such that a tip tool can be attached thereto,
The drive-side rotation member is formed with the first groove, the second groove, and the drive-side inclined surface on the side opposite to the side on which the tip tool is attached in the major axis direction of the rotation shaft. A grinder characterized by that. A grinder according to claim 4,
The drive-side rotation member includes a gear portion to which the rotation output of the rotation drive portion is transmitted, and the gear teeth constituting the gear portion are on the opposite side of the major axis direction to the side on which the tip tool is attached A grinder characterized by being formed. The grinder according to any one of claims 3 to 5,
A buffer member disposed between the driving side rotating member and the driven side rotating member;
The buffer member is
When the rolling member contacts the first groove, it contacts only one of the driving side rotating member and the driven side rotating member,
A grinder having a thickness that abuts both the driving side rotating member and the driven side rotating member when the rolling member abuts on the second groove. The grinder according to any one of claims 3 to 6,
The grinder characterized in that the second groove has a circumferential length that restricts the free movement of the rolling member in the rotational direction when the rolling member abuts. A grinder according to claims 2-7,
The grinder characterized in that the urging member constantly urges the driving-side rotating member and the driven-side rotating member in a direction approaching each other. A grinder according to claim 1,
A grinder comprising a rotation restricting member for restricting rotation of the rotating shaft.

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