JP6351102B2 - Work tools - Google Patents

Description

  The present invention relates to a work tool that rotationally drives a tip tool.

  Japanese Patent Application Laid-Open No. 9-011148 discloses a screw tightening tool that performs screw tightening by driving a bit attached to an output shaft member. In this screw tightening tool, in a state where a screw attached to the tip of a bit is pressed against a work material, a motor rotationally drives an output shaft member to perform a screw tightening operation.

JP-A-9-011148

  In the above screw tightening tool, the unscrewing operation is performed by rotating the motor in the direction opposite to that during the screw tightening operation. In screw tightening work and screw unscrewing work, the tip tool is driven in different directions, but the operator must visually check the direction of rotation of the tip tool, which is a factor that directly affects workability. Become. Therefore, the present invention has been made in view of the above, and it is an object of the present invention to provide a technique that contributes to improving workability by facilitating confirmation of a driving state of a work tool by an operator.

The above problems are solved by the present invention. According to the preferable form of the work tool which concerns on this invention, the work tool which rotates and drives the front-end | tip tool removably mounted | worn at the front-end | tip area | region is comprised. The work tool includes a motor, a tip tool drive shaft that is driven to rotate by the motor to drive the tip tool, and a switching device that switches between a forward rotation direction and a reverse rotation direction of the tip tool driven by the tip tool drive shaft, A rotation direction notifying device for notifying an operator of the rotation direction of the tip tool switched by the switching device ; The operation member preferably includes a trigger and a push button. The switching device typically switches the direction in which the tip tool is driven by switching the rotation direction of the motor. Further, typically, the rotation direction of the tip tool drive shaft matches the rotation direction of the tip tool.

  The notification mode by the rotation direction notification device is as follows: (1) A mode in which the rotation direction of the tip tool is notified to the operator by a predetermined notification method only when the tip tool is driven to rotate in the normal rotation direction. A mode in which the rotation direction of the tip tool is notified to the operator by a predetermined notification method only when the tip tool is rotated in the reverse rotation direction, and (3) the tip tool is driven to rotate in the normal rotation direction and the reverse rotation direction, respectively. In doing so, it preferably includes a mode in which the operator is notified by different notification methods.

  According to the present invention, when the operator operates the operation member to drive the motor, the rotation direction of the tip tool is notified to the operator. Therefore, the operator can confirm whether or not the tip tool is driven as intended, and thereby the operator can recognize whether there is an operation error of the switching device, a malfunction of the work tool, or the like. In particular, in the configuration in which the reverse rotation direction of the tip tool is notified when the motor is driven by the operation of the operation member in a state where the switching device is switched so that the tip tool is driven in the reverse rotation direction, By notifying the drive in the reverse rotation direction of the tool, if the tip tool is rotated in the forward rotation direction during normal work, it is reasonable for the operator that the work tool is in a use state other than during normal work. To be notified.

Furthermore, in the work tool according to the present invention, the rotation direction notifying device uses the sound and / or vibration generated with the driving of the driven member driven by the motor to determine the rotation direction of the tip tool. To inform. Typically, the driven member is constituted by a tip tool driving shaft.
For example, the rotation direction notification device may be configured to generate a sound only when the tip tool is driven to rotate in either the forward rotation direction or the reverse rotation direction. The sound, the scale, and the rhythm of the sound that is generated when the tip tool is rotationally driven in the rotational direction and the sound that is generated when the tip tool is rotationally driven in the reverse rotational direction may be different.
The rotation direction notifying device uses a sound and / or vibration generated by the rotation of the tip tool driving shaft that causes the tip tool driving shaft driven by the motor to drive the tip tool in the reverse rotation direction. It is preferable to notify.
According to the present embodiment, not only the motor drives the tip tool drive shaft but also the rotation direction notifying device by utilizing the sound and / or vibration generated by driving the driven member driven by the motor. To do. Thereby, the number of parts of a work tool is reduced. In particular, when the tip tool drive shaft is set as the driven member, the number of parts of the work tool is further reduced.

According to the further form of the working tool which concerns on this invention, it is comprised as a screw fastening tool which performs a screw fastening operation | work by rotating a tip tool drive shaft around an axis | shaft and rotating a tip tool. Preferably, the tip tool drive shaft is movable between a first position close to the tip region and a second position spaced from the tip region with respect to the axial direction of the tip tool drive shaft. When the tip tool drive shaft is positioned at the first position, the tip tool drive shaft is not rotatable in the direction for driving the tip tool in the forward rotation direction, and in the direction for driving the tip tool in the reverse rotation direction. The tip tool drive shaft is configured to be rotatable in a direction in which the tip tool is driven in the forward rotation direction and the reverse rotation direction when the tip tool drive shaft is located at the second position.
According to the present embodiment, as a work tool, in a screw tightening tool in which a tip tool is rotationally driven in a forward rotation direction to perform screw tightening work, and the tip tool is rotationally driven in a reverse direction to perform screw removal work. The rotation direction is notified. Further, when the tip tool drive shaft is positioned at the first position, the rotation of the tip tool drive shaft in the positive rotation direction that is the screw tightening direction of the tip tool is restricted.

According to the further form of the working tool which concerns on this invention, when the front-end tool drive shaft is located in the housing | casing which accommodates a front-end tool drive shaft and is mounted in a housing, a front-end tool is driven to a reverse rotation direction. And a rotation restricting mechanism that restricts the rotation of the tip tool drive shaft in the direction in which the tip tool is rotated in the forward rotation direction. The rotation restricting mechanism generates a sound and / or vibration along with the rotation of the tip tool driving shaft that drives the tip tool in the reverse rotation direction when the tip tool driving shaft is located at the first position . Typically, the rotation restricting mechanism constituting the rotation direction notifying device is constituted by an engaging portion that rotates integrally with the tip tool drive shaft and an engaged portion on the housing side. Therefore, when the tip tool driving shaft is positioned at the first position, the rotation of the tip tool driving shaft that drives the tip tool in the forward rotation direction is restricted by the engagement between the engaging portion and the engaged portion. Moreover, an engaging part and an engaged part may be comprised with the cam. That is, when the tip tool drive shaft is positioned at the first position, the rotation of the tip tool drive shaft that drives the tip tool in the forward rotation direction is restricted by the engagement of the cam. On the other hand, when the tip tool drive shaft is positioned at the first position, the tip tool drive shaft is rotated so that the tip tool is driven in the reverse rotation direction by a driving force capable of releasing the engagement of the cam. A rotation direction notifying device is constituted by sound and / or vibration caused by engagement and release of the cam. In addition, it is preferable that a periodic sound is generated by the engagement and release of the cam.

  According to the further form of the working tool which concerns on this invention, it has the housing which accommodates a front-end tool drive shaft, and the buffer member arrange | positioned between a front-end tool drive shaft and a housing. The buffer member cushions an impact between the tip tool drive shaft and the housing when the tip tool drive shaft is moved from the second position to the first position and disposed at the first position. Typically, the buffer member is formed of an elastic element such as an elastomer, and the shock is buffered by elastic deformation of the elastic element.

  According to the further form of the working tool which concerns on this invention, it has an elastic member for suppressing the vibration transmission transmitted to a housing via a rotation control mechanism while fixing a rotation control mechanism with respect to a housing. . Thereby, the kinetic energy of vibration is reduced by elastic deformation of the elastic member, and vibration transmission to the housing is suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which contributes to the improvement of workability | operativity is provided in a work tool.

It is a side view showing the whole screw driver composition concerning a 1st embodiment of the present invention. It is a partial bottom view of a screw driver. It is a whole sectional view of a screwdriver. It is sectional drawing in the IV-IV line of FIG. It is sectional drawing in the VV line of FIG. It is a side view of a drive mechanism. It is a perspective view of a drive mechanism. It is a perspective view of a retainer. It is a perspective view of a lock sleeve. It is sectional drawing in the XX line of FIG. It is sectional drawing in the XI-XI line of FIG. It is sectional drawing in the XII-XII line | wire of FIG. It is a perspective view of a stopper. It is a disassembled perspective view of a stopper. It is sectional drawing in the XV-XV line | wire of FIG. FIG. 5 is a cross-sectional view corresponding to FIG. 4 during a screw tightening operation. FIG. 7 is a side view corresponding to FIG. 6 during a screw tightening operation. It is sectional drawing in the XVIII-XVIII line of FIG. It is sectional drawing in the XIX-XIX line | wire of FIG. It is sectional drawing in the XX-XX line of FIG. FIG. 13 is a cross-sectional view corresponding to FIG. 12 during a screw removing operation. FIG. 12 is a cross-sectional view corresponding to FIG. 11 during a screw removing operation. FIG. 16 is a cross-sectional view corresponding to FIG. 15, showing a state where the rotation of the spindle in the screw tightening direction is restricted by the stopper. It is the elements on larger scale which show an oil seal. It is sectional drawing in the XXV-XXV line | wire of FIG. It is a disassembled perspective view of the stopper in 2nd Embodiment of this invention. It is sectional drawing of the stopper at the time of screw removal operation | work. It is a fragmentary sectional side view of the screwdriver which concerns on 3rd Embodiment of this invention. FIG. 29 is a cross-sectional view corresponding to FIG. 28 during a screw tightening operation. It is a perspective view of a drive mechanism. It is an expanded view which shows the cam part of a flange part. It is a perspective view of a stopper. It is an expanded view which shows the engaging part of a stopper. It is a schematic diagram which shows the 1st state of a stopper and a flange part. It is a schematic diagram which shows the 2nd state of a stopper and a flange part. It is a schematic diagram which shows the 3rd state of a stopper and a flange part. It is a schematic diagram which shows the 4th state of a stopper and a flange part.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, as an example of a work tool, a screw driver 100 that performs a predetermined work on a workpiece such as a gypsum board is configured. The screw driver 100 is mainly composed of a main body 101 and a handle 107. A tool bit 119 is detachably attached to the tip region of the main body 101. For convenience of explanation, the tool bit 119 side (right side in FIG. 1) is defined as the front side of the screw driver 100 with respect to the major axis direction (left and right direction in FIG. 1) of the tool bit 119, and the handle 107 side (left side in FIG. 1). ) Is defined as the rear side of the screwdriver 100. 1, the upper side of FIG. 1 is defined as the upper side of the screw driver 100, and the lower side of FIG. 1 is defined as the lower side of the screw driver 100.

  As shown in FIGS. 1 to 3, the main body 101 is configured mainly with a main housing 103, a front housing 104, and a locator 105. The main housing 103 mainly accommodates the motor 110. The front housing 104 is attached to the front side of the main housing 103 and accommodates the drive mechanism 120.

  As shown in FIG. 3, a partition wall 103 a for partitioning the interior of the front housing 104 and the interior of the main housing 103 is provided at the front end of the main housing 103 so as to extend in the vertical direction. The output shaft 111 of the motor 110 is rotatably supported by a bearing 111 a held by the partition wall 103 a and a bearing 111 b held by the rear portion of the main housing 103. The output shaft 111 is arranged in parallel to the long axis direction of the tool bit 119 (spindle 160). The locator 105 is attached so as to cover the front housing 104 at the front end region of the front housing 104. The tool bit 119 is detachably attached to the drive mechanism 120 so that the tip of the tool bit 119 protrudes forward from the locator 105 in the tip region of the main body 101. The locator 105 is movable relative to the front housing 104 in the long axis direction of the tool bit 119, and is fixed at a predetermined position selected in the long axis direction. Thereby, the protrusion amount from which the tool bit 119 protrudes from the locator 105 is appropriately set. That is, the screw tightening depth is set.

  The handle 107 is connected to the rear of the main body 101 (main housing 103). The handle 107 is provided with a trigger 107a and a changeover switch 107b. When the trigger 107a is operated, a current is supplied from the outside via the power cable 109, and the motor 110 is driven. Further, the rotation direction of the output shaft 111 of the motor 110 is switched by operating the changeover switch 107b. That is, the output shaft 111 is driven by selecting one of the rotation directions of forward rotation and reverse rotation. The motor 110 is an implementation configuration example corresponding to the “motor” in the present invention. The trigger 107a and the changeover switch 107b are implementation configuration examples corresponding to the “operation member” and the “switching device” in the present invention, respectively.

[Drive mechanism]
As shown in FIGS. 3 to 12, the drive mechanism 120 is mainly composed of a drive gear 125, a retainer 130, a roller 140, a lock sleeve 145, a spring receiving member 150, a coil spring 155, a spindle 160 and the like.

[Drive gear]
As shown in FIGS. 4 and 5, the drive gear 125 is disposed coaxially with the spindle 160 that holds the tool bit 119. The drive gear 125 is a substantially cup-shaped member that has a bottom wall 126 and a side wall 127 and is opened forward. A through-hole through which the rear shaft portion 162 of the spindle 160 passes is provided at the center of the bottom wall 126. Inside the side wall 127, an internal space formed in a cylindrical shape is formed. A retainer 130, a roller 140, a lock sleeve 145, a coil spring 155, and the like are accommodated in the internal space of the drive gear 125. Gear teeth 128 that engage with gear teeth 112 formed on the output shaft 111 of the motor 110 are provided on the outer periphery of the side wall 127. The drive gear 125 is supported by a needle bearing 121 provided behind the bottom wall 126 so as to be rotatable with respect to the main body 101 (the partition wall 103a).

[Retainer]
As shown in FIGS. 4 to 8 and FIGS. 9 to 12, the retainer 130 is a substantially cup-shaped member and is disposed coaxially with the drive gear 125. The retainer 130 has a base 131 that faces the bottom wall 126 of the drive gear 125, and a first side wall 132 and a second side wall 133 that face the side wall 127 of the drive gear 125. 6 and 7, the drive gear 125 is not shown.

  As shown in FIGS. 4, 8 and 12, the base 131 is provided with a through hole through which the rear shaft 162 of the spindle 160 passes. As shown in FIG. 12, the through hole of the base 131 is provided with an engagement hole 131 a having a predetermined length in the circumferential direction of the spindle 160. On the other hand, as shown in FIG. 4, a groove portion 162 a extending in the axial direction of the spindle 160 is formed in the rear shaft portion 162 of the spindle 160. As shown in FIG. 12, the cross section of the groove 162 a orthogonal to the axial direction of the spindle 160 is formed in a substantially semicircular shape corresponding to the cylindrical engagement pin 139 that connects the spindle 160 and the retainer 130. . Therefore, since the engagement hole 131a has a predetermined length in the circumferential direction of the spindle 160, the spindle 160 is within the range of the engagement hole 131a with the engagement pin 139 engaged with the spindle 160 and the retainer 130. The retainer 130 is configured to be relatively rotatable.

  As shown in FIGS. 4 to 8 and 11, the first side wall 132 and the second side wall 133 are formed so as to protrude forward from the base 131 in the axial direction (front-rear direction) of the retainer 130. . A pair of first side walls 132 and a pair of second side walls 133 are formed on both sides of the central axis of the retainer 130. In other words, the second side wall 132 is interposed between the first side walls 132 in the circumferential direction of the retainer 130. A side wall 133 is disposed. As shown in FIG. 11, with respect to the circumferential direction of the retainer 130, a roller holding part 134 for holding the roller 140 formed as a predetermined space is provided between the first side wall 132 and the second side wall 133. Yes. Accordingly, the retainer 130 holds the four rollers 140 between the first side wall 132 and the second side wall 133.

  Further, as shown in FIGS. 6 to 8, the front end portion of the second side wall 133 is provided with an inclined portion 133 a composed of an inclined surface inclined with respect to the rotation axis of the spindle 160 (the central axis of the retainer 130). It has been. The inclined portions 133 a formed on the two second side walls 133 are formed symmetrically with respect to the central axis of the retainer 130. In other words, the two inclined portions 133a are configured as lead surfaces formed along the circumferential direction of the retainer 130, and have the same angle with respect to the outline (outer periphery) of the retainer 130 in a cross section orthogonal to the axial direction of the retainer 130. It is formed to be inclined at. That is, the two inclined portions 133a are formed in a double spiral shape.

  As shown in FIGS. 5, 6, and 12, the base 131 is formed with a ball holding portion 131 b in a region corresponding to each of the two second side walls 133. The two ball holding portions 131b are formed point-symmetrically with respect to the central axis of the retainer 130. The ball holding portion 131 b is formed as a groove deeper than the thickness of the second side wall 133 in the radial direction of the retainer 130. As a result, as shown in FIG. 5, the outside and the inside of the retainer 130 communicate with each other through the ball holding portion 131 b in the radial direction of the retainer 130.

  As shown in FIG. 12, the ball holding portion 131b has a groove depth that is the distance from the outer peripheral surface of the retainer 130 to the center side of the retainer 130 in the ball holding portion 131b in the radial direction of the retainer 130. It is formed so as to be asymptotically shallow along the direction. Specifically, the depth of the ball holding portion 131b is set so that the groove of the ball holding portion 131b gradually becomes shallower in the clockwise direction (B direction) indicated by the arrow B in FIG. Balls 153 are arranged on the two ball holding portions 131b, respectively. When the ball 153 is located in a region where the groove depth of the ball holding portion 131b is shallow, the ball 153 includes the bottom wall (center side wall) of the ball holding groove 131b and the inner peripheral surface of the drive gear 125. It arrange | positions so that it may contact | abut. On the other hand, when the ball 153 is located in a region where the groove of the ball holding portion 131b is deep, the ball 153 contacts at least one of the bottom wall of the ball holding groove 131b and the inner peripheral surface of the drive gear 125. do not do.

[Lock sleeve]
As shown in FIGS. 4 to 7, 9, and 10, the lock sleeve 145 is a substantially hexagonal columnar member, and a hollow portion is formed inside. The lock sleeve 145 is disposed in front of the retainer 130 so as to be coaxial with the retainer 130 and the drive gear 125. The front end portion of the lock sleeve 145 is disposed so as to be able to contact the rear end portion of the front shaft portion 161 of the spindle 160. The lock sleeve 145 has four roller engaging portions 146 that can be engaged with the rollers 140 and two retainer engaging portions that can be engaged with the second side wall 133 of the retainer 130 corresponding to the six sides of the hexagon. 147.

  As shown in FIG. 10, the roller engaging portion 146 is configured by four planes parallel to the rotation axis of the spindle 160 (the central axis of the lock sleeve 145). Note that the two opposing surfaces are formed parallel to each other. The roller engaging portion 146 is configured to be engageable (contactable) with the roller 140 on the center side of the first side wall 132 and the second side wall 133 in the radial direction of the retainer 130.

  Also, as shown in FIG. 10, the retainer engaging portion 147 is formed in a region that is substantially the same distance as the radius of the retainer 130 from the central axis of the lock sleeve 145 in the radial direction of the retainer 130. As shown in FIGS. 6, 7, and 9, with respect to the front-rear direction, the rear end portion of the retainer engaging portion 147 has an inclined surface that is inclined with respect to the rotation axis of the spindle 160 (the central axis of the lock sleeve 145). A configured inclined portion 147a is provided. The inclined portion 147a is formed corresponding to the inclined portions 133a of the two second side walls 133, respectively. That is, the inclined portion 147a can be engaged (contactable) with the inclined portion 133a. Therefore, similarly to the inclined portion 133a, the two inclined portions 147a are formed point-symmetrically with respect to the central axis of the lock sleeve 145. In other words, the two inclined portions 147a are configured as lead surfaces formed along the circumferential direction around the axial direction of the lock sleeve 145, and the outer shape of the retainer engaging portion 147 in a cross section orthogonal to the axial direction of the lock sleeve 145. It is formed so as to be inclined at the same angle with respect to the line (outer periphery). That is, the two inclined portions 147a are formed in a double spiral shape.

[Spring receiving member]
As shown in FIGS. 4, 5, and 11, the spring receiving member 150 is a member having a substantially hexagonal cross section and is accommodated inside the retainer 130. The spring receiving member 150 is disposed between the base 131 of the retainer 130 and the lock sleeve 145 in the front-rear direction. The spring receiving member 150 has a through hole through which the spindle 160 passes. Then, the engaging pin 139 disposed in the groove 162a of the rear shaft portion 162 engages with a substantially semicircular engaging hole 150a formed in the spring receiving member 150, whereby the spring receiving member 150 is , Coupled to the spindle 160 so as to rotate integrally with the spindle 160. Four roller engaging portions 151 corresponding to four of the six hexagonal sides are formed on the outer periphery of the spring receiving member 150. The roller engaging portion 151 is formed as a plane parallel to the rotation axis of the spindle 160.

  Further, as shown in FIG. 5, a ball contact portion 152 that contacts the ball 153 is formed on the rear surface of the spring receiving member 150. The ball abutting portion 152 abuts the region of the ball 153 closer to the rotation axis of the retainer 130 (the rotation axis of the spindle 160) than the center of the ball 153 with respect to the radial direction of the retainer 130. Acts to push outward in the direction. Note that the ball contact portion 152 may be formed as an inclined surface that is inclined with respect to the axial direction of the spindle 160. The ball 153 pushed outward in the radial direction of the spindle 160 abuts on the inner peripheral surface of the drive gear 125. Accordingly, the ball 153 moves in the ball holding portion 131b by the rotation of the drive gear 125.

[spindle]
As shown in FIGS. 4 to 7 and FIGS. 10 to 12, the spindle 160 is a long, substantially columnar member made of metal and extends in the major axis direction of the spindle 160 (the major axis direction of the tool bit 119). It is provided to be movable. The spindle 160 is mainly composed of a front shaft portion 161 and a rear shaft portion 162 integrally connected to the front shaft portion 161. A tool bit 119 is detachably attached to the front shaft portion 161. The tool bit 119 is engaged with a ball urged by a leaf spring held on the front shaft portion 161, whereby the tool bit 119 is held on the front shaft portion 161. The front shaft portion 161 is rotatably supported by a front bearing 122 held by the front housing 104. As shown in FIGS. 4 and 5, an oil seal 181 is provided between the front housing 104 and the front shaft portion 161 in front of the front bearing 122 that supports the front shaft portion 161. .

  The rear shaft portion 162 is connected to the front shaft portion 161 coaxially with the front shaft portion 161. The rear end portion of the rear shaft portion 162 is slidable in the front-rear direction with respect to a cylindrical rear end bearing 165 provided on the partition wall 103a of the main housing 103, and is supported rotatably. . The rear end bearing 165 is configured as an oilless bearing. As a result, the spindle 160 is supported by the front bearing 122 and the rear end bearing 165. The rear shaft portion 162 passes through the drive gear 125, the retainer 130 and the lock sleeve 145, and the rear end portion of the rear shaft portion 162 protrudes rearward from the drive gear 125. The rear shaft portion 162 is formed with a groove portion 162a extending in the rotation axis direction of the spindle 160. The rear end portion of the groove portion 162a abuts on the engagement pin 139, so that the axial direction of the spindle 160 is related. Forward movement is restricted. On the other hand, the engagement pin 139 is in contact with the rear end portion of the coil spring 155 and is restricted from moving forward in the axial direction of the spindle 160.

  A hollow portion 163 that opens to the rear end surface of the rear shaft portion 162 and extends in the major axis direction of the spindle 160 is formed in the rear shaft portion 162. That is, the hollow portion 163 communicates with the rear end bearing 165. The rear shaft portion 162 is formed with a communication hole 164 that penetrates the rear shaft portion 162 in the radial direction and communicates the hollow portion 163 with the interior of the front housing 104. Therefore, the inside of the front housing 104 and the inside of the rear end bearing 165 communicate with each other through the hollow portion 163. Thereby, when the spindle 160 moves rearward, the compression of the air inside the rear end bearing 165 is restricted. In other words, since the communication hole 164 is provided, the air inside the rear end bearing 165 is not compressed, and the backward movement of the spindle 160 is not hindered.

  Further, as shown in FIGS. 4 and 5, a large diameter portion 166 that can be engaged with the stopper 170 and a small diameter portion 167 that cannot be engaged with the stopper 170 are formed at the rear end portion of the front shaft portion 161. Yes. As shown in FIG. 15, the large-diameter portion 166 has an arc-shaped portion 166a having a diameter D1 and a two-surface width portion 166b having a width W. On the other hand, as shown in FIG. 20, the small diameter portion 167 is formed in a circular shape having a diameter D2. The length of the diameter D2 is the same length as the width W of the two-surface width portion 166b.

[Coil spring]
As shown in FIGS. 4 and 5, the coil spring 155 is disposed so that the spindle 160 penetrates coaxially with the spindle 160. The front region of the coil spring 155 is accommodated in the hollow portion of the lock sleeve 145, and the front end portion of the coil spring 155 is in contact with the lock sleeve 145. The rear end of the coil spring 155 is in contact with the front surface of the spring receiving member 150. As a result, the coil spring 155 biases the lock sleeve 145 and the spindle 160 forward. The lock sleeve 145 biased forward biases the spindle 160 and abuts against the stopper 170 to restrict forward movement. The coil spring 155 urges the spring receiving member 150, the ball 153, the retainer 130, and the drive gear 125 toward the rear. As shown in FIG. 5, the ball 153 is urged by the coil spring 155 and is pushed out toward the outside in the radial direction of the retainer 130 via the ball contact portion 152 of the spring receiving member 150. Abuts on the inner surface.

[Stopper]
As shown in FIGS. 4 and 5, the stopper 170 constitutes a rotation prevention mechanism that restricts the rotation of the spindle 160 in a predetermined direction when the spindle 160 is located at the front position. The stopper 170 is formed in a ring shape, and is disposed on the outer peripheral portion of the spindle 160 so that the spindle 160 passes therethrough. The stopper 170 is fixed to the front housing 104 by an O-ring 180 disposed between the front housing 104 and the front housing 104. As shown in FIGS. 13 to 15, the stopper 170 is mainly composed of a ball holding ring 171, a push ring 173, a ball 175 and a leaf spring 177.

  As shown in FIGS. 13 and 14, the ball holding ring 171 is a metal ring-like member, and holds a ball 175 that can be engaged with the spindle 160. As shown in FIGS. 14 and 15, the ball holding ring 171 is formed with two holding grooves 172 along the circumferential direction. A ball 175 is held in the holding groove 172 so as to be movable in the circumferential direction of the ball holding ring 171. With respect to the radial direction of the ball holding ring 171, the holding groove 172 has an asymptotic depth along the circumferential direction of the ball holding ring 171 that is the distance from the inner peripheral surface of the ball holding ring 171 to the bottom surface of the holding groove 172. It is formed to be deep. Specifically, the depth (the length in the radial direction) of the holding groove 172 is set so that the holding groove 172 gradually becomes deeper in the B direction (screw removing direction) in FIG. A pocket-shaped region 172a is formed in the front portion of the holding groove 172 in the B direction. The wall with which the ball 175 strikes when moving in the B direction in the holding groove 172 extends in a predetermined radial direction of the ball holding ring 171, thereby forming a pocket-shaped region 172 a in the holding groove 172. Therefore, when the ball 175 is positioned at the position shown in FIG. 15 (pocket-shaped region 172a), the ball 175 is held in the pocket-shaped region 172a, so that the center of the ball holding ring 171 in the radial direction (of the spindle 160). The movement of the ball 175 toward the rotation axis) is restricted.

  A substantially C-shaped leaf spring 177 is disposed on the inner periphery of the ball holding ring 171. As shown in FIG. 14, the leaf spring 177 is formed with two through holes 177a corresponding to the two holding grooves 172, respectively. A part of the ball 175 protrudes toward the center of the ball holding ring 171 through the through hole 177a. That is, the ball 175 has a diameter larger than the depth of the holding groove 172. Therefore, the leaf spring 177 functions as a drop-off preventing member that prevents the ball 175 from dropping from the holding groove 172 to the center of the ball holding ring 171 in the radial direction of the ball holding ring 171. With the above configuration, the protruding amount of the ball 175 protruding from the through hole 177a of the leaf spring 177 varies depending on the position of the ball 175 in the holding groove 172.

  As shown in FIGS. 13 and 14, the leaf spring 177 has an engagement hole 177 b that engages with the ball 176 held by the ball holding ring 171. With the leaf spring 177 disposed on the inner peripheral portion of the ball holding ring 171, the ball 176 is fitted into the holding ring 171 using the elastic deformation of the leaf spring 177 and then the ball 175 is fitted into the holding groove 172. The ball holding ring 171, the ball 175, and the leaf spring 177 are integrated. Note that the holding groove 172 is open toward the rear, and the ball 175 is moved from the rear of the ball holding ring 171 and disposed in the holding groove 172. On the other hand, the ball 176 is moved from the front of the ball holding ring 171 and engages with the engagement hole 177 b of the leaf spring 177. A holding hole for holding the ball 176 is formed in the ball holding ring 171 so that the ball 176 engaged with the leaf spring 177 cannot move rearward of the ball holding ring 171. As a result, the ball 175 that cannot move forward, the ball 176 that cannot move backward, and the leaf spring 177 are associated with each other while being engaged with the ball holding ring 171, and each component of the stopper 170 is assembled. The As a result, the assembly of the stopper 170 to the front housing 104 is simplified.

  As shown in FIGS. 13 and 14, the push ring 173 is a ring-shaped member having a smaller diameter than the ball holding ring 171 and is accommodated in the ball holding ring 171 coaxially with the ball holding ring 171. The front end surface of the push ring 173 is in contact with the ball 175 held by the ball holding ring 171. The push ring 173 can rotate relative to the ball holding ring 171. The rear end surface of the push ring 173 can contact and separate from the shoulder portion of the lock sleeve 145 that is offset rearward from the front end surface of the lock sleeve 145. That is, as shown in FIG. 5, when the lock sleeve 145 is biased by the coil spring 155 and is positioned at the front position, the lock sleeve 145 and the push ring 173 come into contact with each other. On the other hand, as shown in FIG. 16, when the lock sleeve 145 is located at the rear position, the lock sleeve 145 and the push ring 173 are separated from each other.

  When the lock sleeve 145 is rotated with the lock sleeve 145 positioned at the front position and in contact with the push ring 173, the push ring 173 contacts the ball 175 and the ball 175 is held. Move in the groove 172. As a result, the amount of protrusion of the ball 175 from the holding groove 172 varies in the radial direction of the ball holding ring 171. That is, as shown in FIG. 20, when the ball 175 moves in the A direction (screw tightening direction), the amount of protrusion of the ball 175 from the leaf spring 177 increases, and as shown in FIG. 15, the B direction (unscrewing). When the ball 175 moves in the direction), the amount of protrusion of the ball 175 from the lease spring 177 decreases. That is, the ball 175 is moved in the circumferential direction of the spindle 160, so that the ball 175 moves away from the center axis of the spindle 160 shown in FIG. 15 (also referred to as a separated position) and close to the center axis of the spindle 160 shown in FIG. Move between positions (also called proximity positions).

  When the ball 175 is positioned at the separated position, the ball 175 does not engage with the large diameter portion 166 and the small diameter portion 167 of the spindle 160. Accordingly, since the ball 175 cannot be engaged with the spindle 160 at the separated position of the ball 175, the separated position is also referred to as an unengageable position. On the other hand, when the ball 175 is located at the close position, the ball 175 can be engaged with the large-diameter portion 166 of the spindle 160. That is, when the ball 175 is located at the close position and the spindle 160 is located at the front position where the large-diameter portion 166 of the spindle 160 faces the ball 175, the ball 175 and the spindle 160 are engaged. On the other hand, when the spindle 160 is positioned at a rear position where the small diameter portion 167 of the spindle 160 and the ball 175 face each other, the ball 175 and the spindle 160 are not engaged. Therefore, since the ball 175 can be engaged with the spindle 160 at the proximity position of the ball 175, the proximity position is also referred to as an engageable position. The movement of the ball 175 in the screw tightening direction switches the ball 175 from the non-engageable position to the engageable position, and the movement of the ball 175 in the unscrewing direction causes the ball 175 to move from the engageable position to the non-engageable position. Can be switched to.

[Operation of screwdriver]
In the screw driver 100 configured as described above, when the trigger 107a is operated, the motor 110 is driven. The drive gear 125 is rotationally driven by the rotation of the output shaft 111 of the motor 110. Then, the rotation of the drive gear 125 is transmitted to the spindle 160, whereby the tool bit 119 held on the spindle 160 is rotated, and a predetermined work (screw tightening work or screw removing work) is performed. This spindle 160 is an implementation configuration example corresponding to the “tip tool drive shaft” in the present invention.

[Screw tightening]
When performing the screw tightening operation, the spindle 160 moves from the front position shown in FIG. 4 to the rear position shown in FIG. 16 by pressing the screw (not shown) at the tip of the tool bit 119 against the workpiece. Is done. The front position and the rear position are implementation configuration examples corresponding to the “first position” and the “second position” in the present invention, respectively. By the movement of the spindle 160, the lock sleeve 145 is rotated with respect to the retainer 130, and the roller 140 is sandwiched between the drive gear 125 and the lock sleeve 145. As a result, the wedge effect of the roller 140 causes the drive gear 125 and the lock sleeve 145 to rotate together, the rotation of the output shaft 111 of the motor 110 is transmitted to the spindle 160 via the drive mechanism 120, and the spindle 160 is rotationally driven. . Thereby, the screw tightening operation is performed by the tool bit 119.

  Specifically, as shown in FIG. 4, when the output shaft 111 of the motor 110 rotates in a predetermined direction (hereinafter referred to as a positive direction) when the spindle 160 is located at the front position, the direction A in FIGS. The driving gear 125 is driven to rotate. At this time, since the roller 140 is not sandwiched between the lock sleeve 145 and the drive gear 125, the rotation of the drive gear 125 is not transmitted to the lock sleeve 145. As shown in FIG. 12, when the driving gear 125 rotates in the A direction, the ball 153 contacts the inner peripheral surface of the driving gear 125 and moves in the A direction in the ball holding portion 131b. Is sufficiently deep (the length in the radial direction), the ball 153 is not sandwiched between the ball holding portion 131b and the drive gear 125. In other words, the ball 153 is held in a loose shape in the ball holding portion 131 b, and the rotation of the drive gear 125 is not transmitted to the retainer 130. This state is also referred to as an idling state.

  When the screw held at the tip of the tool bit 119 is pressed against the workpiece from the idling state, the spindle 160 resists the biasing force of the coil spring 155 and the spindle 160 moves from the front position shown in FIG. 4 to the rear position shown in FIG. Moved to. Accordingly, the lock sleeve 145 is pushed by the rear end portion of the front shaft portion 161 of the spindle 160 and moves rearward, and the retainer engaging portion 147 of the lock sleeve 145 and the second side wall 133 of the retainer 130 come into contact with each other. That is, as shown in FIG. 17, the inclined portion 147 a of the retainer engaging portion 147 and the inclined portion 133 a of the second side wall 133 come into contact with each other. As the inclined portion 147a moves along the inclined portion 133a, the lock sleeve 145 moves rearward and rotates around the axis of the retainer 130. That is, as shown in FIG. 18, the lock sleeve 145 rotates relative to the retainer 130 by a predetermined angle around the rotation axis of the spindle 160 in the B direction. As a result, the distance between the roller engaging portion 146 of the lock sleeve 145 and the inner peripheral surface of the drive gear 125 is shortened, and the roller 140 is sandwiched between the roller engaging portion 146 and the inner peripheral surface of the drive gear 125. Thereby, the roller 140 acts as a wedge, and the drive gear 125 and the lock sleeve 145 are integrated via the roller 140. The position of the roller 140 held between the lock sleeve 145 and the drive gear 125 (the position in FIG. 18) is also referred to as a rotation transmission position. Therefore, the neutral position of the roller 140 that is not sandwiched between the lock sleeve 145 and the drive gear 125 (the position in FIG. 10) is also referred to as a rotation transmission impossible position.

  At this time, as shown in FIG. 17, the inclined portion 147 a of the lock sleeve 145 is in contact with the inclined portion 133 a of the retainer 130. Therefore, as shown in FIG. 18, when the drive gear 125 is rotationally driven in the direction A by the output shaft 111 of the motor 110, the lock sleeve 145 integrated with the drive gear 125 is rotated. The inclined portion 147a presses the retainer 130 in the A direction, and rotates the retainer 130 in the A direction.

  As illustrated in FIG. 19, the retainer 130 rotated in the A direction rotates the spindle 160 in the A direction (screw tightening direction) via the engagement pin 139 that engages with the engagement hole 131 a of the retainer 130. As a result, the screw tightening operation is performed by the tool bit 119 held on the spindle 160. As shown in FIG. 16, when the spindle 160 is located at the rear position, the small diameter portion 167 of the spindle 160 faces the ball 175 of the stopper 170. Since the ball 175 does not engage with the small diameter portion 167, the rotation of the spindle 160 in the screwing direction is not hindered.

  When the screw is screwed into the workpiece, the entire screw driver 100 moves forward with the movement of the screw, and the front surface of the locator 105 contacts the workpiece. After the locator 105 comes into contact with the workpiece, when a screw is further screwed into the workpiece, the spindle 160 holding the tool bit 119 moves toward the front of the screw driver 100 with respect to the locator 105 (front housing 104). Moving. That is, the spindle 160 is allowed to move from the rear position shown in FIG. 16 to the front position shown in FIG. In other words, since the spindle 160 is pressed before the locator 105 contacts the workpiece, the relative movement between the spindle 160 and the locator 105 is restricted with respect to the rotation axis direction of the spindle 160.

  The urging force of the coil spring 155 acts forward on the spindle 160 via the lock sleeve 145. Further, the lock sleeve 145 presses the retainer 130 and moves (rotates) the retainer 130 around the rotation axis of the spindle 160, so that the lock sleeve 145 receives a reaction force from the retainer 130. Specifically, since the lock sleeve 145 and the retainer 130 are in contact with the inclined portion 147a and the inclined portion 133a that are inclined with respect to the rotation axis of the spindle 160, the lock sleeve 145 is a reaction force in the rotation axis direction of the spindle 160. And receives a reaction force around the rotation axis.

  Therefore, during the screw tightening operation, if the spindle 160 is allowed to move from the rear position to the front position after the locator 105 contacts the workpiece, the resultant force of the biasing force of the coil spring 155 and the reaction force from the retainer 130 is obtained. The lock sleeve 145 is moved forward from the position shown in FIG. 16 by (force in the rotation axis direction of the spindle 160). That is, the resultant force exceeds the frictional force between the roller 140 and the lock sleeve 145. In other words, the frictional force between the roller 140 and the lock sleeve 145 is not increased only by the urging force of the coil spring 155, and the resultant force of the urging force of the coil spring 155 and the reaction force from the retainer 130 is between the roller 140 and the lock sleeve 145. Exceeds frictional force. Therefore, the lock sleeve 145 is not moved forward only by the urging force of the coil spring 155, and the lock sleeve 145 is moved forward by the resultant force of the urging force of the coil spring 155 and the reaction force from the retainer 130. As a result, the lock sleeve 145 and the retainer 130 are separated from each other in the rotation axis direction of the spindle 160, and a gap is formed between the retainer 130 and the lock sleeve 145. As a result, the lock sleeve 145 shown in FIG. 18 is rotated relative to the drive gear 125 in the A direction, and the nipping of the roller 140 between the drive gear 125 and the lock sleeve 145 is released. That is, the wedge action of the roller 140 is released. Accordingly, the rotation transmission from the drive gear 125 to the spindle 160 is interrupted, and the screw tightening operation is completed.

[Unscrewing work]
During the unscrewing operation for removing the screw screwed into the workpiece, the screw driver 100 (tool bit 119) rotates the screw in the reverse direction, thereby removing the screw from the workpiece. In this unscrewing operation, it is not reasonable to press the tool bit 119 against the screw. Therefore, in the screw driver 100, the tool bit 119 is driven by the motor 110 without pressing the tool bit 119 in the screw removing operation. That is, the spindle 160 (tool bit 119) is rotated in the reverse direction when the spindle 160 is in the forward position.

  Specifically, as shown in FIG. 1, at the time of unscrewing work, the changeover switch 107b is switched so that the output shaft 111 of the motor 110 rotates in a direction opposite to the forward direction (hereinafter referred to as the reverse direction). An LED 107c is provided in the vicinity of the changeover switch 107b, and the LED 107c emits light when the trigger 107a is operated in a state where the rotation direction of the output shaft 111 is switched to the reverse direction. That is, the operator is informed that the unscrewing operation is performed by the LED 107c. When the output shaft 111 of the motor 110 rotates in the reverse direction, the drive gear 125 rotates in the B direction in FIGS. At this time, since the roller 140 is not sandwiched between the lock sleeve 145 and the drive gear 125, the rotation of the drive gear 125 is not transmitted to the lock sleeve 145.

  On the other hand, the rotation of the drive gear 125 in the B direction causes the ball 153 shown in FIG. 12 to contact the inner peripheral surface of the drive gear 125 and move in the B direction in the ball holding portion 131b, and is arranged at the position shown in FIG. The Since the depth (the length in the radial direction) of the ball holding portion 131b becomes shallower (shorter) in the B direction, the ball 153 moves in the B direction in the ball holding portion 131b, so that the ball holding portion 131b It is clamped by the drive gear 125. Thereby, the ball 153 acts as a wedge, and the drive gear 125 and the retainer 130 are integrated via the ball 153.

  As shown in FIG. 21, the engagement hole 131a formed in the retainer 130 has a predetermined length in the circumferential direction of the spindle 160, and relative rotation between the spindle 160 and the retainer 130 is allowed. On the other hand, as shown in FIG. 22, relative rotation of the spring receiving member 150 with respect to the spindle 160 is restricted via the engagement pin 139. Therefore, when the retainer 130 is rotated in the B direction integrally with the drive gear 125, the retainer 130 rotates in the B direction with respect to the spindle 160 and the spring receiving member 150, and the roller 140 held by the retainer 130 is moved in the B direction. Moved to. As a result, the roller 140 is sandwiched between the spring receiving member 150 and the drive gear 125. Accordingly, the roller 140 acts as a wedge, and the drive gear 125, the spring receiving member 150, and the spindle 160 are integrated via the roller 140. Therefore, when the drive gear 125 is rotated in the B direction, the spindle 160 is rotated in the B direction (unscrewing direction). As a result, the unscrewing operation is performed by the tool bit 119 held on the spindle 160.

  In the screw driver 100 described above, the screw tightening operation is performed when the spindle 160 is located at the rear position. Since the screw tightening operation is performed by attaching screws one by one to the tip of the tool bit 119, it is preferable that the spindle 160 is surely stopped when the spindle 160 is located at a front position where it is not rotationally driven. . That is, in the idling state, it is preferable that the spindle 160 is stopped about the rotation axis of the spindle 160. Therefore, in the present embodiment, the stopper 170 is provided to prevent the spindle 160 from unintentionally rotating in the screw tightening direction when the spindle 160 is located at the front position. Note that the stopper 170 is prevented from rotating by the ball holding ring 171 of the stopper 170 being fixed to the front housing 104 by the O-ring 180. This O-ring 180 is an implementation configuration example corresponding to the “elastic member” in the present invention.

  Specifically, as shown in FIG. 4, when the spindle 160 is located at the front position, the large-diameter portion 166 of the spindle 160 faces the ball 175 of the stopper 170. At this time, even if the drive gear 125 is rotationally driven in the A direction, the lock sleeve 145 and the spindle 160 are not normally rotated. However, if the lock sleeve 145 is rotated for some reason, the coil spring 155 is biased. Since the lock sleeve 145 is in contact with the push ring 173, the ball 175 is moved through the push ring 173 in the holding groove 172 by the rotation of the drive gear 125 in the A direction (screw tightening direction) as shown in FIG. Moved in the direction. The depth (the length in the radial direction) of the holding groove 172 is configured to become shallower (shorter) in the A direction. When the ball 175 is disposed at the position shown in FIG. The protruding amount of the protruding ball 175 is maximized. As a result, the large-diameter portion 166 of the spindle 160 contacts the ball 175, and the rotation of the spindle 160 in the A direction is restricted. In particular, as shown in FIG. 23, the ball 175 engages with the two-surface width portion 166b of the large diameter portion 166 to restrict the rotation of the spindle 160 in the A direction. This stopper 170 is an implementation structural example corresponding to the “rotation restricting mechanism” in the present invention.

  On the other hand, the screw removing operation is performed without pressing the tool bit 119 held by the spindle 160 against the workpiece. That is, the unscrewing operation is performed with the spindle 160 positioned at the front position. As shown in FIG. 4, when the spindle 160 is located at the front position, the large-diameter portion 166 of the spindle 160 faces the ball 175 of the stopper 170. At this time, when the drive gear 125 is rotationally driven in the B direction, the lock sleeve 145 urged by the coil spring 155 is in contact with the push ring 173, so that the drive gear 125 rotates in the B direction (unscrewing direction). Thus, the ball 175 is moved in the B direction through the push ring 173 in the holding groove 172 as shown in FIG. The depth (the length in the radial direction) of the holding groove 172 is configured to be deeper (longer) in the B direction. When the ball 175 is disposed at the position shown in FIG. The diameter portion 166 does not contact the ball 175. The stopper 170 allows the spindle 160 to rotate in the unscrewing direction when the spindle 160 is positioned at the front position. Therefore, the unscrewing operation is performed without the ball 175 preventing the rotation of the spindle 160 in the B direction (unscrewing direction).

  Further, in the screw driver 100 described above, as shown in FIG. 4, a lubricant (not shown) such as grease is disposed in the front housing 104 in order to drive the drive mechanism 120 smoothly. Further, in order to prevent the lubricant from flowing out from the front side of the front housing 104, an oil seal 181 is interposed between the outer peripheral portion of the front shaft portion 161 of the spindle 160 and the front housing 104 on the front side of the front housing 104. Are arranged to be. That is, the front housing 104 is formed in a sealed shape.

  As shown in FIG. 24, the oil seal 181 is formed in a ring shape, and has a base portion 181 a attached to the front housing 104 and a lip portion 181 b that contacts the spindle 160. In particular, the base portion 181a that contacts the inner peripheral surface of the front housing 104 is formed of an elastomer. A large diameter portion 104 c having a diameter slightly larger than the outer diameter of the oil seal 181 is formed at the front end portion of the front housing 104. Further, the outer diameter of the oil seal 181 is slightly larger than the inner diameter of the front housing 104. Further, an upper recess 104 a and a lower recess 104 b are formed on the inner peripheral surface of the front housing 104. That is, the plurality of recesses 104a and 104b are formed on the same circumference. In addition, the recessed part may be comprised as a single recessed part formed continuously in the circumferential direction. Further, a convex portion may be provided instead of the concave portion.

  The above oil seal 181 is engaged with the front housing 104 by elastic deformation of the outer peripheral portion of the oil seal 181 by being moved from the front of the front housing 104. At this time, the oil seal 181 is moved along the large diameter portion 104 c of the front housing 104. That is, the large diameter portion 104c functions as a guide when the oil seal 181 is assembled. Further, due to the elastic deformation of the base portion 181 a of the oil seal 181, the recesses 104 a and 104 b and the base portion 181 a of the oil seal 181 are engaged, and the oil seal 181 is firmly fixed so as not to drop off from the front housing 104. That is, the recesses 104 a and 104 b function as a retaining stopper for the oil seal 181. The oil seal 181 is press-fitted into the front housing 104 by elastic deformation, whereby the circumferential rotation of the oil seal 181 is restricted. However, the oil seal 181 is formed in the front housing 104 with respect to the circumferential direction of the oil seal 181. The rotation of the oil seal 181 in the circumferential direction is more effectively suppressed by the plurality of recesses 104a and 104b. Then, the drive mechanism 120 is assembled to the front housing 104 to which the oil seal 181 is assembled. That is, the drive mechanism 120 is disposed in the front housing 104 so that the spindle 160 penetrates the oil seal 181, so that the oil seal 181 is disposed so as to seal the gap between the spindle 160 and the front housing 104. . Note that the lip portion 181 b provided on the inner peripheral portion of the oil seal 181 always abuts on the spindle 160. This prevents the lubricant from flowing out from the front side of the front housing 104.

  On the other hand, on the rear side of the front housing 104, as shown in FIG. 25, the bearing 111a prevents the lubricant from flowing out between the output shaft 111 of the motor 110 and the partition wall 103a. Further, the partition wall 103 a is provided with a ventilation passage 190 that communicates the inside and the outside of the front housing 104. When the screw driver 100 is driven, heat is generated by driving the drive mechanism 120 in the front housing 104, and the pressure of air in the front housing 104 increases. In particular, in the small screw driver 100, since the volume of the front housing 104 is small, the pressure fluctuation of the air in the front housing 104 is large. Therefore, the partition wall 103a is formed with a ventilation passage 190 for suppressing the pressure increase of the air in the front housing 104 by releasing the pressure of the front housing 104 to the outside. That is, the front housing 104 and the main housing 103 communicate with each other through the ventilation passage 190. The ventilation passage 190 is provided behind the drive gear 125 and above the output shaft 111 (not shown in FIG. 25) of the motor 110. As shown in FIGS. 1 and 3, the main housing 103 is provided with an external communication portion 106 configured by a communication hole that communicates the inside of the main housing 103 and the outside of the screw driver 100.

  As shown in FIG. 25, the ventilation passage 190 protrudes forward from the partition wall 103a extending in the vertical direction in order to allow the air inside and outside the front housing 104 to flow and to suppress the outflow of the lubricant. It is comprised by the hollow part of the cylindrical (chimney-like) channel | path formation part 191. FIG. That is, the vent 191a at the front end portion (tip portion) of the passage forming portion 191 is provided at a predetermined distance forward from the front surface 103f (surface on the front housing 104 side) of the partition wall 103a. Thereby, it is suppressed that a lubricant moves to the vent 191a along the partition wall 103a. The vent 191 a is disposed in the vicinity of the drive gear 125. Further, the vent 191 a is provided on the rotational axis side of the drive gear 125 with respect to the radial direction of the drive gear 125 with respect to the outer peripheral portion of the drive gear 125. Centrifugal force is generated by the rotation of the drive gear 125, and the lubricant adhering to the drive gear 125 is moved outward in the radial direction of the drive gear 125. Therefore, the lubricant can be prevented from entering the vent passage 190 from the vent 191a. The ventilation passage 190 prevents the lubricant from flowing out from the front housing 104, and suppresses an increase in air pressure in the front housing 104.

  Further, an oil filter 195 is disposed on the partition wall 103a in preparation for the case where the lubricant flows out from the ventilation passage 190 having the above configuration. The oil filter 195 is made of a material that absorbs liquid, such as felt or sponge. The oil filter 195 is disposed behind the partition wall 103a and behind the ventilation passage 190. That is, the oil filter 195 is held by the partition wall 103a. Therefore, the air in the front housing 104 passes through the ventilation passage 190 and the oil filter 195 and reaches the main housing 103.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment differs from the first embodiment in the shape of the holding groove formed in the ball holding ring of the stopper 170. Therefore, components other than the holding groove are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  As shown in FIG. 15, in the first embodiment, the pocket-shaped region 172a is formed in the holding groove 172. However, in the second embodiment, instead of the pocket-shaped region 172a, as shown in FIG. A radial movement allowable region 272 a is formed in the holding groove 272. The wall with which the ball 175 abuts when moving in the B direction in the holding groove 272 extends along a predetermined tangent line of the inner peripheral portion of the ball holding ring 271, thereby allowing radial movement to the holding groove 272. Region 272a is formed. Therefore, when the ball 175 is positioned at the position shown in FIG. 27 (radial movement allowable region 272a), the ball 175 is allowed to move toward the radial center of the ball holding ring 271 (the rotation axis of the spindle 160). Is done.

  During the unscrewing operation, the rotation of the push ring 173 in the B direction causes the ball 175 to contact the push ring 173 and move in the holding groove 272 in the B direction, and is disposed in the radial movement allowable region 272a. The ball 175 disposed in the radial movement allowable region 272a is further moved toward the radial center (radial inner side) of the ball holding ring 271 by the rotation of the push ring 173 in the B direction. As a result, the ball 175 collides with the large-diameter portion 166 of the spindle 160 rotating in the unscrewing direction (B direction), and the ball 175 is moved radially outward in the radial movement allowable region 272a. Thereafter, the ball 175 is moved again toward the radial center (radially inward) of the ball holding ring 271 by the rotation of the push ring 173 in the B direction. That is, during the unscrewing operation, the ball 175 periodically moves between the radially outer side and the radially inner side in the radial movement allowable region 272a.

  As a result, the ball 175 periodically collides with the large-diameter portion 166 of the spindle 160, and a collision sound is generated. This collision sound constitutes a rotation direction notifying device for notifying the operator that the spindle 160 is being rotated in the unscrewing direction. That is, when the spindle 160 is located at the front position, the stopper 170 restricts rotation of the spindle 160 in the screw tightening direction, allows rotation in the screw unscrewing direction, and the spindle 160 is rotated in the screw unscrewing direction. It also has a function to notify this. Therefore, prior to the unscrewing operation, the operator can easily confirm the rotation direction (unscrewing direction) of the spindle 160. Therefore, in the second embodiment, the LED 107c may not be provided.

  According to the first and second embodiments described above, when the screw tightening operation is performed, the spindle 160 is pressed and moved to the rear position, whereby the inclined portion 147a of the lock sleeve 145 and the inclined portion 133a of the retainer 130 are moved. The roller 140 is moved in the circumferential direction of the retainer 130 with respect to the lock sleeve 145 by the engagement. That is, with respect to the circumferential direction of the retainer 130, the roller 140 is moved from the rotation transmission impossible position to the rotation transmission position. Therefore, by converting the movement of the spindle 160 in the axial direction of the spindle 160 into the movement of the roller 140 in the circumferential direction of the retainer 130 (spindle 160), the position of the roller 140 can be rationally switched based on the screw tightening operation. .

  Further, according to the first and second embodiments, by using the roller 140, the rotation of the output shaft 111 of the motor 110 is caused to rotate by the wedge effect of the roller 140 sandwiched between the drive gear 125 and the lock sleeve 145. 160 is reliably transmitted.

  Further, according to the first and second embodiments, the clamping of the roller 140 by the drive gear 125 and the lock sleeve 145 is released along with the movement of the screw (spindle 160) during the screw tightening operation. Specifically, the roller is obtained by the resultant force of the urging force of the coil spring 155 in the axial direction of the spindle 160 and the axial reaction force of the spindle 160 that the lock sleeve 145 receives from the retainer 130 when the lock sleeve 145 rotates the retainer 130. The holding of 140 is released. That is, in order to release the clamping of the roller 140 only by the urging force of the coil spring 155, a large urging force of the coil spring 155 is required. However, by utilizing the reaction force that the lock sleeve 145 receives from the retainer 130, The clamping is reliably released, and the rotation transmission by the drive mechanism 120 is interrupted. In addition, a spring having a small spring constant can be applied to the coil spring 155 by utilizing the reaction force that the lock sleeve 145 receives from the retainer 130.

  Further, according to the first and second embodiments, the stopper 170 restricts the rotation of the spindle 160 in the screw tightening direction in the idling state. This reliably prevents the spindle 160 from unintentionally rotating due to, for example, a lubricant solidified in the front housing 104. Therefore, when performing the screw tightening operation, the spindle 160 is driven to rotate only when the spindle 160 is pressed. On the other hand, since the stopper 170 allows the rotation of the spindle 160 in the unscrewing direction, the spindle 160 is rotationally driven without pressing the spindle 160 when performing the screw removing operation. Thereby, the spindle 160 is rationally driven according to the work mode.

  Further, according to the first and second embodiments, since the oil seal 181 is provided on the front side of the front housing 104, the lubricant is prevented from flowing out from the front side of the front housing 104. This prevents contamination of the screw and workpiece. The oil seal 181 is prevented from coming off in the axial direction of the spindle 160 by elastic deformation of the base portion 181 a of the oil seal 181, and circumferential rotation associated with the rotation of the spindle 160 is restricted. In other words, the oil seal 181 is firmly fixed in the axial direction and the circumferential direction of the spindle 160. Further, since the recesses 104a and 104b are formed in the front housing 104, the movement of the oil seal 181 in the axial direction and the circumferential direction of the spindle 160 is more effectively restricted. The fixing of the oil seal 181 is particularly useful for the spindle 160 that rotates in the axial direction and is moved in the axial direction.

  Further, according to the first and second embodiments, the ventilation passage 190 suppresses the increase in the pressure of the air in the front housing 104. Further, the lubricant that has flowed out of the ventilation passage 190 is reliably captured by the oil filter 195, and the lubricant is prevented from flowing out of the screw driver 100. In the configuration in which the output shaft 111 of the motor 110 is disposed in parallel to the axial direction of the spindle 160 (tool bit 119), the motor 110 is disposed behind the drive mechanism 120 in consideration of the position of the center of gravity of the screw driver 100. . Therefore, an empty space is generated behind the drive mechanism 120 and above the motor 110. Since the ventilation passage 190 and the oil filter 195 are arranged in such an empty space, the components of the screw driver 100 are rationally arranged.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. The third embodiment is different from the above-described embodiment in informing means for informing the screw removal work. Specifically, in the third embodiment, the spindle 360 and the stopper 370 are different from the above-described embodiment. Therefore, components other than the spindle 360 and the stopper 370 are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  As shown in FIGS. 28 to 30, the drive mechanism 120 is mainly composed of a drive gear 125, a retainer 130, a roller 140, a lock sleeve 145, a spring receiving member 150, a coil spring 155, a spindle 360, and the like.

  As shown in FIG. 28, the spindle 360 is mainly configured with a front shaft portion 361 and a rear shaft portion 362 integrally connected to the front shaft portion 361. A tool bit 119 is detachably attached to the front shaft portion 361. The front shaft portion 361 is rotatably supported by a front bearing 122 held by the front housing 104. Further, an oil seal 181 is provided between the front housing 104 and the front shaft portion 161 in front of the front bearing 122 that supports the front shaft portion 361.

  The rear shaft portion 362 is connected to the front shaft portion 361 coaxially with the front shaft portion 361. The rear end portion of the rear shaft portion 362 is slidable in the front-rear direction with respect to a cylindrical rear end bearing 165 provided on the partition wall 103a of the main housing 103, and is supported rotatably. . The rear end bearing 165 is configured as an oilless bearing. Thus, the spindle 360 is supported by the front bearing 122 and the rear end bearing 165. The rear shaft portion 362 passes through the drive gear 125, the retainer 130 and the lock sleeve 145, and the rear end portion of the rear shaft portion 362 protrudes rearward from the drive gear 125. Similar to the first embodiment, the rear shaft portion 362 is formed with a groove portion 162a extending in the direction of the rotation axis of the spindle 360, and the rear end portion of the groove portion 162a abuts on the engagement pin 139. Thus, the forward movement of the spindle 360 in the axial direction is restricted. On the other hand, the engagement pin 139 is in contact with the rear end portion of the coil spring 155 and is restricted from moving forward in the axial direction of the spindle 160. 28 and 29, the spindle 360 is shown rotated 90 degrees around the rotation axis with respect to the spindle 160 shown in FIGS. 4 and 16, and the groove 162a and the engagement pin 139 are shown. Is not shown.

  A hollow portion 363 that opens to the rear end surface of the rear shaft portion 362 and extends in the major axis direction inside the spindle 360 is formed inside the rear shaft portion 362. That is, the hollow portion 363 communicates with the rear end bearing 165. The rear shaft portion 362 is formed with a communication hole 364 that penetrates the rear shaft portion 362 in the radial direction and communicates the hollow portion 363 with the interior of the front housing 104. Therefore, the interior of the front housing 104 and the interior of the rear end bearing 165 communicate with each other through the hollow portion 363. Thus, as shown in FIG. 29, when the spindle 360 moves rearward, the compression of the air inside the rear end bearing 165 is restricted. In other words, the communication hole 364 is provided, so that the air inside the rear end bearing 165 is not compressed and the backward movement of the spindle 360 is not hindered.

  Further, a flange portion 366 that can be engaged with the stopper 370 is formed at the rear end portion of the front shaft portion 361. The flange portion 366 is formed to protrude in the radial direction at the front shaft portion 361. As shown in FIG. 30, the flange portion 366 has cam portions 367 formed at four locations in the circumferential direction. That is, the cam portion 367 is provided every 90 degrees with respect to the circumferential direction of the flange portion 366. The cam portion 367 constitutes a cam that can come into contact with the stopper 370.

  Specifically, as shown in FIG. 31, the flange portion 366 has four protrusions protruding from the base portion 368 toward the front (upward in FIG. 31) with respect to the rotation axis direction of the spindle 360 (up and down direction in FIG. 31). A cam portion 367 is formed. The cam portion 367 includes an inclined portion 367a, a flat portion 367b, and an inclined portion 367c. The inclined portion 367a and the inclined portion 367c are formed symmetrically with respect to the center of the cam portion 367. Adjacent cam portions 367 are connected by a base portion 368. Therefore, the base 368, the inclined portion 367a, the flat portion 367b, and the inclined portion 367c are continuous with respect to the circumferential direction of the spindle 360. Further, as shown in FIGS. 28 to 30, a rubber cushioning material 369 is provided in front of the cam portion 367. The cushioning material 369 is an annular member and is engaged with the outside of the front shaft portion 361 of the spindle 360. The front surface of the cushioning material 369 can abut on the front bearing 122.

  As shown in FIGS. 28 and 29, the stopper 370 is a metal ring-shaped member, and is arranged on the outer peripheral portion of the spindle 360 so that the spindle 360 penetrates. The stopper 370 is fixed to the front housing 104 by an O-ring 180 that is interposed between the stopper 370 and the front housing 104.

  As shown in FIGS. 32 and 33, the stopper 370 is formed with an engaging portion 371 that protrudes inward in the radial direction. The engaging portion 371 is provided every 90 degrees with respect to the circumferential direction of the stopper 370. The engaging portion 371 can come into contact with the cam portion 367 of the flange portion 366.

  In the screw driver 300 having the above-described configuration, the spindle 360 can move between the front position shown in FIG. 28 and the rear position shown in FIG. 29. As in the first embodiment, the screw driver 300 is screwed according to the position of the spindle 360. Tightening and unscrewing operations are performed.

  At the time of the screw tightening operation, as shown in FIG. 29, the spindle 360 is pressed against the workpiece via the tool bit 119 holding a screw (not shown), and the spindle 360 is positioned at the rear position. Therefore, the flange portion 366 and the stopper 370 are not engaged during the screw tightening operation. In this screw tightening operation, when the spindle 360 is located at a front position where it is not rotationally driven (idling state), it is preferable that the spindle 360 is stopped around the rotation axis of the spindle 360. Therefore, in the third embodiment, the stopper 370 is provided to prevent the spindle 360 from unintentionally rotating in the screw tightening direction when the spindle 360 is located at the front position.

  Specifically, in the first state of the stopper 370 and the flange portion 366 shown in FIG. 34, the spindle 360 is not normally rotated even when the drive gear 125 is rotationally driven in the A direction (screw tightening direction). However, it is assumed that the spindle 360 is rotated in the A direction for some reason. For example, a minute driving force is transmitted to the spindle 360 in an idling state by a frictional force or the like caused by the solidified lubricant. In this case, a small part of the torque of the output shaft 111 is transmitted to the spindle 360. When the spindle 360 (flange portion 366) is rotated in the A direction, as shown in FIG. 37, the inclined portion 377a of the cam portion 377 contacts the engaging portion 371 of the stopper 370 (fourth state). At this time, the spindle 360 (flange portion 366) is biased forward by the coil spring 155. Therefore, rotation of the spindle 360 in the A direction by a minute driving force is restricted by the biasing force of the coil spring 155 and the contact between the inclined portion 377a of the cam portion 377 and the engaging portion 371 of the stopper 370. This stopper 370 is an implementation configuration example corresponding to the “rotation restricting mechanism” in the present invention.

  On the other hand, at the time of unscrewing work, as shown in FIG. 28, the spindle 360 is positioned at the front position. Therefore, the flange portion 366 and the stopper 370 engage with each other during the screw removal operation. When the spindle 360 is located at the front position, the flange portion 366 contacts the cushioning material 369. Therefore, as shown in FIG. 34, when the cam portion 377 of the flange portion 366 and the engaging portion 371 of the stopper 370 are not engaged, that is, when the flange portion 366 and the stopper 370 are not in contact, the flange portion A gap C is formed between the base 368 of 366 and the stopper 370. That is, the front position of the spindle 360 is defined by the cushioning material 369 that contacts the front bearing 122, and at this time, the base 368 does not contact the stopper 370.

  When the flange portion 366 is rotated in the direction B (unscrewing direction) by the torque of the output shaft 111 from the first state shown in FIG. 34, the inclined portion 367c of the cam portion 367 is shown in FIG. The flange portion 366 rotates in the B direction while coming into contact with the engaging portion 371 of the stopper 370 (second state). Accordingly, the flange portion 366 (spindle 360) is moved rearward (downward in FIG. 35) in the rotation axis direction of the spindle 360 against the urging force of the coil spring 155. When the engaging portion 371 rides on the inclined portion 367c, as shown in FIG. 36, the flange portion 366 rotates in the B direction so that the flat portion 367b of the cam portion 367 follows the engaging portion 371 (third state). . That is, the engagement of the cam portion 367 as the cam mechanism and the engaging portion 371 is released. At this time, the base portion 368 of the flange portion 366 and the stopper 370 are farthest apart from each other in the rotation axis direction of the spindle 360, and a gap C1 is formed between the base portion 368 of the flange portion 366 and the stopper 370. That is, the spindle 360 is moved in the direction of the rotation axis of the spindle 360 (the front-rear direction of the screw driver 300) during the unscrewing operation, but the difference between the clearance C and the clearance C1 is the tool bit 119. And a small distance that does not affect the engagement of the screw head.

  Thereafter, as shown in FIG. 37, the flange portion 366 rotates in the B direction while the inclined portion 367a of the cam portion 367 contacts the engaging portion 371 of the stopper 370 (fourth state). Thereby, the flange portion 366 (spindle 360) is moved forward (upward in FIG. 37) in the rotation axis direction of the spindle 360. Thereby, as shown in FIG. 28, the cushioning material 369 collides with the front bearing 122. Thereafter, as shown in FIG. 34, the cam portion 367 and the engaging portion 371 are brought into a first state where they are not engaged.

  By the rotation of the flange portion 366 in the B direction, the first to fourth states of the stopper 370 and the flange portion 366 shown in FIGS. 34 to 37 are repeated. As a result, the cushioning material 369 periodically collides with the front bearing 122, and periodic vibration and / or sound is generated. That is, since the flange portion 366 and the stopper 370 are provided, the spindle 360 is moved by a minute distance in the front-rear direction, so that the cushioning material 369 periodically collides with the front bearing 122. Accordingly, periodic vibrations and / or sounds are generated according to the operation of the trigger 107a for starting the screw removal work, and the operator is notified of the rotation of the spindle 360 in the screw removal direction. At this time, the buffer material 369 prevents the base 368 of the flange portion 366 and the metal of the stopper 370 from colliding with each other. This cushioning material 369 is an implementation configuration example corresponding to the “buffering member” in the present invention. Note that the cushioning material 369 is not provided, and the rotation direction notifying device may be configured using sound generated by the collision between the base 368 and the metal of the stopper 370.

  As described above, the cam portion 367 of the flange portion 366 and the engaging portion 371 of the stopper 370 restrict the rotation of the spindle 360 in the idling state before the screw tightening operation, and the spindle 360 moves in the screw unscrewing direction during the screw removing operation. It constitutes a part of a rotation direction notifying device that notifies that it is rotating, and thus has a plurality of functions. Therefore, in the third embodiment, the LED 107c may not be provided.

  According to the third embodiment described above, the same effects as those in the first and second embodiments can be obtained with respect to the rational drive of the spindle 360, the prevention of lubricant outflow by the oil seal 181 and the ventilation passage 190. .

  In the above embodiment, the LED 107c is lit to notify that the unscrewing operation is performed. However, the present invention is not limited to this. For example, you may alert | report that the unscrewing operation | work is performed by blinking LED107c or changing the color of the light which LED107c emits. An actuator that generates vibration and sound may be provided as the rotation direction notification device. The rotation direction notifying device not only notifies the rotation of the spindle 160, 360 (tool bit 119) in the unscrewing direction at the time of screw removal work, but also the screw of the spindle 160, 360 (tool bit 119) at the time of screw tightening work. You may alert | report rotation of a tightening direction.

  In the above embodiment, the mechanical contact between the inclined portions 133a and 147a cooperates with the urging force of the coil spring 155 to release the holding of the roller 140 by the drive gear 125 and the lock sleeve 145. The lock sleeve 145 is moved forward, but is not limited thereto. That is, the lock sleeve 145 may be moved forward only by contacting the inclined portions 133a and 147a by appropriately setting the angles of the inclined surfaces of the inclined portions 133a and 147a. Further, for example, separately from the inclined portions 133a and 147a, it is detected that the locator 105 is in contact with the workpiece during the screw tightening operation, and the lock sleeve 145 is moved forward, so that the drive gear 125 and the lock sleeve are moved. A releasing means for releasing the holding of the roller 140 by 145 may be provided. Further, only one of the inclined portions 133a and the inclined portion 147a may be provided.

  Moreover, in the above embodiment, the inside of the drive gear 125 that is a drive member has a cylindrical shape, and the outside of the lock sleeve 145 that is a driven member is formed in a prismatic shape, but this is not a limitation. That is, the inside of the driving member may be a prismatic shape, and the outside of the driven member may be formed in a columnar shape.

In view of the gist of the present invention, the following modes can be configured for the work tool according to the present invention. Each aspect is used not only alone or in combination with each other, but also in combination with the invention described in the claims.
(Aspect 1)
The tip tool drive shaft is configured to reciprocate a predetermined distance with respect to the axial direction of the tip tool drive shaft by being rotationally driven in the reverse rotation direction at the first position.
Sound and / or vibration is generated by the reciprocating movement of the tip tool drive shaft in the axial direction.
(Aspect 2)
The tip tool drive shaft is configured to move between the first position and the third position between the first position and the second position by being driven to rotate in the reverse rotation direction at the first position. Has been
Sound and / or vibration is generated by the movement of the first position and the third position of the tip tool drive shaft.
(Aspect 3)
A housing that houses the tip tool drive shaft;
The rotation direction notifying device includes an engaging portion formed so as to rotate integrally with the tip tool drive shaft, and an engaged portion provided on the housing side.
(Aspect 4)
The engaged portion is movable with respect to the housing between an engaging position where the engaged portion engages with the engaging portion and an unengageable position where the engaging portion cannot engage with the engaging portion.
(Aspect 5)
A housing that houses the tip tool drive shaft;
The rotation direction notifying device has a first cam portion formed so as to rotate integrally with the tip tool drive shaft, and a second cam portion fixed to the housing and engageable with the first cam portion. ,
When the tip tool drive shaft is located at the first position, the rotation of the tip tool drive shaft in the positive rotation direction is restricted by the engagement of the first cam portion and the second cam portion, and the first cam portion is the second cam portion. By riding on the cam portion, the tip tool drive shaft is rotationally driven in the reverse rotation direction by the motor so that the engagement between the first cam portion and the second cam portion is released.
(Aspect 6)
At least one of the first cam portion and the second cam portion has a cam surface that intersects the rotational direction of the tip tool drive shaft,
The first cam portion and the second cam portion engage with each other as the tip tool drive shaft rotates.
(Aspect 7)
When the tip tool drive shaft is located at the first position, the tip tool drive shaft is rotationally driven in the reverse rotation direction, and engagement and disengagement of the first cam portion and the second cam portion occur periodically. Thereby, a sound and / or vibration is generated as the rotation direction notification device.
(Aspect 8)
At least one of the first cam portion and the second cam portion includes a first inclined portion and a second inclined portion formed symmetrically.
(Aspect 9)
When the tip tool drive shaft is located at the first position, the tip tool drive shaft is configured not to be rotated in the forward rotation direction by the motor but to be driven in the reverse rotation direction by the motor,
When the tip tool drive shaft is located at the second position, the tip tool drive shaft is configured to be driven by the motor in each of the normal rotation direction and the reverse rotation direction.
(Aspect 10)
The buffer member is constituted by an O-ring attached to the tip tool drive shaft.
(Aspect 11)
The elastic member is configured by an O-ring.

(Correspondence between each component of this embodiment and each component of the present invention)
The correspondence between each component of the present embodiment and each component of the present invention is shown as follows. In addition, this embodiment shows an example of the form for implementing this invention, and this invention is not limited to the structure of this embodiment.
The screw driver 100 is an example of a configuration corresponding to the “screw tightening tool” of the present invention.
The motor 110 is an example of a configuration corresponding to the “motor” of the present invention.
The spindle 160 is an example of a configuration corresponding to the “tip tool drive shaft” of the present invention.
The trigger 107a is an example of a configuration corresponding to the “operation member” of the present invention.
The changeover switch 107b is an example of a configuration corresponding to the “switching device” of the present invention.
The stoppers 170 and 370 are an example of a configuration corresponding to the “rotation restricting mechanism” of the present invention.
The O-ring 180 is an example of a configuration corresponding to the “elastic member” of the present invention.
The buffer material 369 is an example of a configuration corresponding to the “buffer member” of the present invention.

DESCRIPTION OF SYMBOLS 100 Screwdriver 101 Main part 103 Main housing 103a Partition wall 103f Front surface 104 Front housing 104a Recess 104b Recess 104c Large diameter part 105 Locator 107 Handle 107a Trigger 107b Changeover switch 107c LED
109 Power cable 110 Motor 111 Output shaft 112 Gear tooth 119 Tool bit 120 Drive mechanism 121 Needle bearing 122 Front bearing 123 Rear bearing 125 Drive gear 126 Bottom wall 127 Side wall 128 Gear tooth 130 Retainer 131 Base 131a Engagement hole 131b Ball holding part 132 1st side wall 133 2nd side wall 133a Inclination part 134 Roller holding part 139 Engagement pin 140 Roller 145 Lock sleeve 146 Roller engagement part 147 Retainer engagement part 147a Inclination part 150 Spring receiving member 150a Engagement hole 151 Roller engagement part 152 Ball contact portion 153 Ball 155 Coil spring 160 Spindle 161 Front shaft portion 162 Back shaft portion 162a Groove portion 163 Hollow portion 164 Communication hole 165 Rear end bearing 166 Large diameter portion 166b Width across flats 167 Small diameter portion 170 Stopper 171 Ball holding ring 172 Holding groove 172a Pocket-shaped region 173 Push ring 175 Ball 176 Ball 177 Leaf spring 177a Through hole 177b Engagement hole 180 O-ring 181 Oil seal 181a Base portion 181b Lip portion 190 Ventilation passage 191 Passage formation portion 191a Ventilation hole 195 Oil filter 271 Ball holding ring 272 Holding groove 272a Radial movement region 360 Spindle 361 Front shaft portion 362 Rear shaft portion 363 Hollow portion 364 Communication hole 366 Flange portion 367 Cam portion 367a Inclining portion 367b Flat portion 367c Inclining portion 368 Base 369 Buffer material 370 Stopper 371 Engagement portion

Claims (8)

A work tool that performs a predetermined work by driving a tip tool that is detachably attached to the tip region,
A motor,
A tip tool drive shaft that is driven by the motor and rotationally drives the tip tool;
An operation member operated by an operator in order to switch between driving and stopping of the motor;
A switching device that switches between a forward rotation direction and a reverse rotation direction of the tip tool driven by the tip tool drive shaft;
A rotation direction notification device for notifying an operator of the rotation direction of the tip tool switched by the switching device ;
The rotation direction notification device is:
A work tool configured to notify an operator of the rotation direction of the tip tool by using sound and / or vibration generated by driving a driven member driven by the motor. . The work tool according to claim 1,
The rotation direction notification device is:
Based on the operation of the operation member for driving the motor in a state where the switching device is switched so that the tip tool is driven in the reverse rotation direction, the rotation direction of the tip tool is the reverse rotation. It is comprised so that it may alert | report that it is a direction, The work tool characterized by the above-mentioned. The work tool according to claim 1 or 2 ,
The driven member is constituted by the tip tool drive shaft,
The rotation direction notifying device uses sound and / or vibration generated by rotation of the tip tool driving shaft driven by the motor to drive the tip tool in the reverse rotation direction. tool. The work tool according to any one of claims 1 to 3 ,
The work tool is configured as a screw tightening tool for performing screw tightening work by rotating the tip tool driving shaft to rotate the tip tool. The work tool according to claim 4 ,
The tip tool drive shaft is configured to be movable between a first position close to the tip region and a second position separated from the tip region with respect to the axial direction of the tip tool drive shaft.
When the tip tool drive shaft is located at the first position, the tip tool drive shaft is not rotatable in a direction for driving the tip tool in the forward rotation direction, and the tip tool is rotated in the reverse rotation direction. Can be rotated in the direction of driving,
When the tip tool drive shaft is located at the second position, the tip tool drive shaft is rotatable in a direction to drive the tip tool in the forward rotation direction and the reverse rotation direction. Work tools. The work tool according to claim 5 ,
A housing that houses the tip tool drive shaft;
When the tip tool drive shaft is mounted on the housing and the tip tool drive shaft is located at the first position, the tip tool drive shaft is allowed to rotate in a direction to drive the tip tool in the reverse rotation direction. A rotation restricting mechanism for restricting the rotation of the tip tool drive shaft in the direction of driving in the positive rotation direction,
The rotation restricting mechanism generates sound and / or vibration along with the rotation of the tip tool driving shaft that drives the tip tool in the reverse rotation direction when the tip tool driving shaft is located at the first position. By doing so, the said rotation direction alerting | reporting apparatus is comprised, The work tool characterized by the above-mentioned . The work tool according to claim 6 ,
A cushioning member disposed between the tip tool drive shaft and the housing;
The buffer member buffers an impact between the tip tool drive shaft and the housing when the tip tool drive shaft is moved from the second position to the first position and disposed at the first position. It is comprised so that the working tool characterized by the above-mentioned. The work tool according to claim 6 or 7 ,
A work tool having an elastic member for fixing the rotation restricting mechanism to the housing and suppressing vibration transmission transmitted to the housing via the rotation restricting mechanism.

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