JP2017042889A - Hammering tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide improved techniques regarding a clutch mechanism of a hammering tool.SOLUTION: A hammer drill 100 comprises an electric motor 110, a motion conversion mechanism 120 driven by the electric motor 110, and a clutch mechanism 180 to transmit rotation of the electric motor 110 to the motion conversion mechanism 120. The clutch mechanism 180 comprises a drive cylinder 181, a lock sleeve 185, a clutch sleeve 190, and a roller 195. Regarding the roller 195, when a hammer bit 119 is pressed against a work piece, the clutch sleeve 190 moves the roller 195 around a rotation axis of the drive cylinder 181, and the roller 195 is sandwiched between the drive cylinder 181 and the lock sleeve 185. Thereby, the wedge effect of the roller 195 integrally rotates the drive cylinder 181 and the lock sleeve 185, and the rotation of the drive cylinder 181 is transmitted to the clutch sleeve 190 to drive the motion conversion mechanism 120.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an impact tool that performs a machining operation on a workpiece.

  Japanese Patent Laid-Open No. 2006-181664 discloses an impact tool. In the impact tool, a power transmission mechanism having a drive motor and a motion conversion mechanism for driving a cylinder are connected by a clutch mechanism. The clutch mechanism is formed so that the clutch teeth of the rotating body provided in the power transmission mechanism and the clutch teeth of the clutch cam provided in the motion conversion mechanism mesh with each other. In a no-load state where the tip tool is not pressed against the machining area, the engagement of the clutch teeth of the rotating body and the clutch teeth of the clutch cam is released, so that the motion conversion is performed while the drive motor is driven. The mechanism is configured not to be driven. On the other hand, in a load state in which the tip tool is pressed against the machining area, the motion conversion mechanism is driven and the tip tool is driven by meshing the clutch teeth of the rotating body and the clutch teeth of the clutch cam.

JP 2006-181664 A

  In the impact tool described above, when shifting from the no-load state to the load state, the clutch teeth of the rotating body that is rotationally driven and the clutch teeth of the clutch cam that is not rotationally driven are meshed. For this reason, there is a possibility that the clutch teeth may wear each other, and further improvement of the clutch is desired. In view of the above, an object of the present invention is to provide an improved technique related to a clutch mechanism in an impact tool.

The above problems are solved by the present invention. According to a preferred embodiment of the impact tool according to the present invention, the tip tool removably attached to the tip region of the tool body is driven in the long axis direction of the tip tool without being driven to rotate around the long axis direction of the tip tool. Thus, a striking tool having a striking drive mode for performing a turning operation on the workpiece is configured. Note that “without rotationally driving the tip tool” means that the rotational drive of the tip tool is regulated by, for example, a predetermined rotational drive restricting member, and that power transmission to the tip tool is performed so that the tip tool is not rotationally driven. The restricted mode is preferably included. This striking tool suitably includes work tools such as a hammer and a hammer drill. This striking tool includes a motor having an output shaft, a striking drive mechanism for driving the tip tool in the long axis direction, and a clutch mechanism capable of transmitting and interrupting driving force to the tip tool. Typically, the clutch mechanism interrupts transmission of torque of the output shaft of the motor and the transmission. Then, the impact driving mechanism to which the torque of the output shaft of the motor is transmitted drives the tip tool in the long axis direction. This striking drive mechanism includes a cylinder, a holding portion that holds the cylinder, and a cylinder drive mechanism that reciprocates the cylinder. Then, the tip tool is driven in the long axis direction by the reciprocating motion of the cylinder. The cylinder drive mechanism is a mechanism that reciprocates the cylinder by the torque of the motor, and is also referred to as a motion conversion mechanism. This cylinder drive mechanism suitably includes a mechanism that performs motion conversion by a swing member that swings in a predetermined direction based on the torque of the motor, and a mechanism that performs motion conversion by a crank member.
The striking drive mechanism typically includes a bottomed cylinder. The cylinder may be connected to a cylinder driving mechanism and configured to be directly driven by the cylinder driving mechanism. In this case, the striking drive mechanism includes a striking element accommodated in the cylinder. The striking element is linearly driven through pressure fluctuations in the air chamber between the cylinder and the striking element generated by the reciprocating motion of the cylinder, and the tip tool is strikingly driven in the long axis direction by the linear driving of the striking element. On the other hand, the cylinder may be configured to be driven by a piston driven by a cylinder drive mechanism. In this case, the impact driving mechanism includes a piston accommodated in the cylinder. The cylinder is linearly driven by pressure fluctuations in the air chamber between the cylinder and the piston caused by the reciprocating motion of the piston, and the tip tool is driven to strike in the long axis direction by the linear driving of the cylinder. That is, the cylinder functions as a striker. An intermediate element may be provided between the striker and the tip tool, and the tip tool may be configured to be driven to strike via the intermediate piece.

  The clutch mechanism includes a drive clutch member that is rotationally driven by the output shaft of the motor, and a driven clutch member that is rotationally driven by transmission of torque of the drive clutch member. The driven clutch member is movable between a torque transmission position where torque is transmitted from the driving clutch member to the driven clutch member and a torque transmission cutoff position where transmission of torque from the driving clutch member to the driven clutch member is blocked. . When the turning work is performed, the tip tool is pressed against the workpiece and the impact driving mechanism is moved, whereby the driven clutch member is moved from the torque transmission blocking position to the torque transmission position. In a state where the driven clutch member is located at the torque transmission position, torque is transmitted from the drive clutch member to the driven clutch member via a frictional force generated between the driven clutch member and the drive clutch member. Thereby, the clutch mechanism transmits the torque of the output shaft to the tip tool, and the tip tool is driven in the long axis direction. The frictional force between the driven clutch member and the driving clutch member is not only configured to be generated when the driven clutch member and the driving clutch member come into contact with each other, but another friction force is generated between the driven clutch member and the driving clutch member. You may be comprised so that it may generate | occur | produce when an intermediate member is clamped. Therefore, at the torque transmission cutoff position, sufficient frictional force for transmitting torque between the driving clutch member and the driven clutch member is not generated. In this case, a configuration in which no frictional force is generated and a configuration in which a slight frictional force is generated are preferably included. Thereby, in the torque transmission cutoff position, transmission of torque from the drive clutch member to the driven clutch member is cut off.

  According to the present invention, the clutch mechanism transmits torque from the drive clutch member to the driven clutch member via a frictional force generated between the drive clutch member and the driven clutch member. That is, the frictional force is used as a torque transmission element. Therefore, wear between the drive clutch member and the driven clutch member when the driven clutch member is switched between the torque transmission position and the torque transmission cutoff position is reduced.

According to the further form of the impact tool which concerns on this invention, the rotational drive mechanism which rotationally drives a front-end tool to the surroundings of the said major axis direction is provided. Furthermore, the tip drive tool is driven to rotate in the long axis direction without being driven linearly in the long axis direction, and a drilling operation is performed on the workpiece, and the tip tool is linearly driven in the long axis direction and long. A drive mode switching unit is provided that switches the drive mode between an impact rotation drive mode in which a hammer drill operation is performed on the workpiece by rotating the shaft around the axis, and an impact drive mode. Note that “without linearly driving the tip tool” means that the linear drive of the tip tool is regulated by, for example, a predetermined linear drive restricting member, and that power transmission to the tip tool is performed so that the tip tool is not linearly driven. The restricted mode is preferably included. This batting drive mode is also referred to as a hammer mode. The striking rotation drive mode is also referred to as a hammer drill mode. On the other hand, the rotational drive mode is also referred to as a drill mode.
In a state where the driving mode switching unit is switched to the striking driving mode or the striking rotation driving mode, the driven clutch member is allowed to move from the torque transmission blocking position to the torque transmitting position, and the tip tool is moved against the workpiece. By being pressed, the driven clutch member is moved from the torque transmission cutoff position to the torque transmission position. On the other hand, in the state switched to the rotational drive mode, the driven clutch member is maintained at the torque transmission cutoff position. In a state where the driven clutch member is located at the torque transmission position, torque is transmitted from the drive clutch member to the driven clutch member via a frictional force generated between the driven clutch member and the drive clutch member. Thereby, the clutch mechanism transmits the torque of the output shaft to the tip tool.

  That is, the clutch mechanism of the present invention is provided for driving the tip tool linearly in the long axis direction of the tip tool, and for rotational drive that transmits torque to the tip tool to rotationally drive the tip tool. It is not provided on the torque transmission path. A further clutch mechanism may be provided on the rotational drive torque transmission path.

  According to this aspect, the permission and restriction of the movement of the driven clutch member are switched according to the drive mode selected by the drive mode switching unit. That is, the movement of the driven clutch member is rationally controlled in conjunction with the drive mode. Further, the driven clutch member is moved from the torque transmission cutoff position to the torque transmission position using the force with which the tip tool is pressed against the workpiece. That is, the driven clutch member is rationally moved according to the work mode, and the clutch mechanism transmits torque.

According to the further form of the impact tool which concerns on this invention, while a drive clutch member is rotationally driven by the motor, it has a rotating shaft line parallel to the major axis direction of a front-end tool. On the other hand, the driven clutch member is arranged coaxially with the rotation axis of the drive clutch member, and is separated from the tip region by the torque transmission cutoff position close to the tip region and the torque transmission cutoff position with respect to the longitudinal direction of the tip tool. It is configured to be movable between torque transmission positions. Further, the clutch mechanism includes a transmission member disposed between the driving clutch member and the driven clutch member. The transmission member has a transmission position for transmitting torque from the drive clutch member to the driven clutch member, and a position different from the transmission position around the rotation axis of the drive clutch member, so that torque can be transmitted from the drive clutch member to the driven clutch member. It is possible to move between impossible transmission positions.
The driven clutch member moves from the torque transmission cut-off position to the torque transmission position by pressing the tip tool against the workpiece and moving the impact driving mechanism. When the driven clutch member is positioned at the torque transmission cutoff position, the transmission member is disposed at the non-transmittable position, and transmission of torque from the drive clutch member to the driven clutch member is blocked. On the other hand, when the driven clutch member is located at the torque transmission position, the transmission member is disposed at the transmission position and driven via the frictional force generated between the transmission member and the driven clutch member and between the transmission member and the drive clutch member. Torque is transmitted from the clutch member to the driven clutch member. The transmission member is configured by a roller, a sphere, or the like.
According to this aspect, the position of the drive clutch member that is rotating is switched while the transmission member moves around the rotation axis of the drive clutch member. Therefore, wear of the transmission member and the drive clutch member is reduced as compared with a clutch having a configuration in which a rotating member and a stopped member are engaged with each other.

According to the further form of the impact tool which concerns on this invention, while a drive clutch member is rotationally driven by the motor, it has a rotating shaft line parallel to the major axis direction of a front-end tool. On the other hand, the driven clutch member is arranged coaxially with the rotation axis of the drive clutch member, and is separated from the tip region by the torque transmission cutoff position close to the tip region and the torque transmission cutoff position with respect to the longitudinal direction of the tip tool. It is configured to be movable between torque transmission positions.
The drive clutch member has a circular cross section perpendicular to the rotation axis of the drive clutch member, and includes a drive taper surface region provided so as to be inclined with respect to the rotation axis. The driven clutch member has a circular cross section perpendicular to the rotation axis of the drive clutch member, and is provided so as to be inclined with respect to the rotation axis, and includes a driven taper surface region capable of contacting the drive taper surface region. Typically, the drive taper surface region and the driven taper surface region are respectively constituted by a conical outer peripheral surface and an inner peripheral surface with the rotation axis as the central axis. The conical shape includes a shape in which a circular cross section orthogonal to the rotation axis increases asymptotically toward the tip region of the tool body, and a circular cross section orthogonal to the rotation axis extends to the rear end region opposite to the tip region of the tool body. And a shape that increases asymptotically is preferably included.
Then, the driven clutch member is moved from the torque transmission blocking position to the torque transmission position when the tip driving tool is pressed against the workpiece and the impact driving mechanism is moved. When the driven clutch member is located at the torque transmission cutoff position, the driven taper surface region and the drive taper surface region are arranged apart from each other. Thereby, the transmission of torque from the drive clutch member to the driven clutch member is interrupted. On the other hand, when the driven clutch member is located at the torque transmission position, the driven taper surface region and the drive taper surface region come into contact with each other, and the driven clutch member is driven by the friction force generated between the driven taper surface region and the drive taper surface region. Torque is transmitted to the clutch member.

According to the further form of the impact tool which concerns on this invention, while a drive clutch member is rotationally driven by the motor, it has a rotating shaft line parallel to the major axis direction of a front-end tool. On the other hand, the driven clutch member is arranged coaxially with the rotation axis of the drive clutch member, and is separated from the tip region by the torque transmission cutoff position close to the tip region and the torque transmission cutoff position with respect to the longitudinal direction of the tip tool. It is configured to be movable between torque transmission positions.
Further, the clutch mechanism includes a driving friction plate and a driven friction plate. The drive friction plate is disposed between the drive clutch member and the driven clutch member and engages with the drive clutch member. That is, the drive friction plate rotates integrally with the drive clutch member. On the other hand, the driven friction plate is disposed between the driving clutch member and the driven clutch member and engages with the driven clutch member. That is, the driven friction plate rotates integrally with the driven clutch member. The drive friction plate and the driven friction plate are arranged side by side in the rotation axis direction of the drive clutch member.
Then, the driven clutch member is moved from the torque transmission blocking position to the torque transmission position when the tip driving tool is pressed against the workpiece and the impact driving mechanism is moved. When the driven clutch member is located at the torque transmission cutoff position, the driving friction plate and the driven friction plate are arranged apart from each other. Thereby, the transmission of torque from the drive clutch member to the driven clutch member is interrupted. On the other hand, when the driven clutch member is positioned at the torque transmission position, torque is transmitted from the driving clutch member to the driven clutch member via a friction force generated between the driving friction plate and the driven friction plate by contacting the driving friction plate and the driven friction plate. Is done.

  ADVANTAGE OF THE INVENTION According to this invention, the improvement technique regarding a clutch mechanism is provided in an impact tool.

It is sectional drawing which shows the whole structure of the hammer drill which concerns on 1st Embodiment of this invention. It is an expanded sectional view showing an internal mechanism of a hammer drill. It is a side view which shows the internal mechanism of a hammer drill. FIG. 4 is a partially enlarged view of FIG. 3. It is the VV sectional view taken on the line of FIG. It is sectional drawing which shows the power transmission state of a clutch mechanism when a hammer bit is pressed. FIG. 5 is a partially enlarged view corresponding to FIG. 4 showing a power transmission state of the clutch mechanism when the hammer bit is pressed. It is the VIII-VIII sectional view taken on the line of FIG. In the hammer drill of FIG. 1, it is sectional drawing which shows the state by which the striking mechanism part was moved back at the time of a process operation. FIG. 10 is a cross-sectional view showing a state where the swing shaft is driven and positioned rearward in the hammer drill of FIG. 9. It is sectional drawing which shows the whole structure of the hammer drill which concerns on 2nd Embodiment of this invention. It is an expanded sectional view which shows the area | region A of FIG. It is sectional drawing which shows the power transmission state of a clutch mechanism when a hammer bit is pressed. It is an expanded sectional view which shows the area | region A of FIG. It is sectional drawing which shows the whole structure of the hammer drill which concerns on 3rd Embodiment of this invention. It is an expanded sectional view which shows the area | region B of FIG. It is the XVII-XVII sectional view taken on the line of FIG. It is the XVIII-XVIII sectional view taken on the line of FIG. The hammer bit is pressed to show the power transmission state of the clutch mechanism It is an expanded sectional view which shows the area | region B of FIG.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. This embodiment will be described using a hand-held hammer drill as an example of an impact tool. As shown in FIG. 1, the hammer drill 100 performs a hammering operation and a drilling operation on a workpiece (for example, concrete) by causing the hammer bit 119 to perform a striking operation in the major axis direction and rotating around the major axis direction. It is a hand-held impact tool. This hammer bit 119 is an implementation configuration example corresponding to the “tip tool” in the present invention.

[Overall configuration of hammer drill]
As shown in FIG. 1, the hammer drill 100 is mainly composed of a main body housing 101 that forms an outline of the hammer drill 100. A hammer bit 119 is detachably attached to the distal end region of the main body housing 101 via a cylindrical tool holder 159. The hammer bit 119 is inserted into the bit insertion hole of the tool holder 159, and can be reciprocated in the long axis direction relative to the tool holder 159, and is relative to the circumferential direction around the long axis direction. The rotation is held in a restricted state. Note that the long axis of the tool holder 159 coincides with the long axis of the hammer bit 119.

  The main body housing 101 is mainly composed of a motor housing 103 and a gear housing 105. With respect to the major axis direction of the hammer bit 119, a hand grip 109 gripped by an operator is connected to the opposite side of the main body housing 101 from the hammer bit 119. In the present embodiment, for the sake of convenience, the hammer bit 119 side (left side in FIG. 1) is defined as the front side with respect to the long axis direction of the hammer bit 119 (the long axis direction of the main body housing 101, the left-right direction in FIG. 1). The side (the right side in FIG. 1) is defined as the rear side.

  In the main body housing 101, the gear housing 105 is disposed on the front side with respect to the long axis direction of the hammer bit 119, and the motor housing 103 is disposed on the rear side of the gear housing 105. Further, a hand grip 109 is connected to the rear of the motor housing 103. The motor housing 103 and the gear housing 105 are fixedly connected by fixing means such as screws. The motor housing 103 and the gear housing 105 are fixedly coupled so as not to move relative to each other, whereby a single main body housing 101 is formed. That is, the motor housing 103 and the gear housing 105 are configured as separate housing bodies for assembling the internal mechanism, and are integrated by a fixing means to constitute a single main body housing 101.

  As shown in FIG. 1, the motor housing 103 houses an electric motor 110. The electric motor 110 is arranged such that the output shaft 111 extends in parallel with the long axis direction of the hammer bit 119. The electric motor 110 is fixed to the motor housing 103 by fixing means such as screws. A motor cooling fan 112 is attached to the front end side (front side) of the output shaft 111 and rotates integrally with the output shaft 111. A pinion gear 113 is provided in front of the fan 112 of the output shaft 111. The pinion gear 113 is formed as a helical gear. A front bearing 114 is provided between the pinion gear 113 and the fan 112. A rear bearing 115 is provided at the rear end of the output shaft 111. Thereby, the output shaft 111 is rotatably supported by the bearings 114 and 115. The front bearing 114 is held by a bearing support 107 that is a part of the gear housing 105, and the rear bearing 115 is held by the motor housing 103. Therefore, the electric motor 110 is held so that the pinion gear 113 projects into the gear housing 105. This electric motor 110 is an implementation configuration example corresponding to the “motor” in the present invention.

  The output shaft 111 of the electric motor 110 is rotationally driven in the normal rotation direction and the reverse rotation direction. The rotation direction of the output shaft 111 is switched by a selector switch 110a that can be manually operated by an operator. The hammer bit 119 is rotationally driven in the forward direction by the rotation of the output shaft 111 in the forward direction, and a drilling operation is performed. On the other hand, the hammer bit 119 is rotationally driven in the reverse direction by the rotation of the output shaft 111 in the reverse direction. By rotating the hammer bit 119 in the reverse direction, for example, when the hammer bit 119 bites into the workpiece, the hammer bit 119 is released from the workpiece. Therefore, the electric motor 110 is optimized so that the drive performance is maximized when rotating in the forward direction. Further, the pinion gear 113 and the fan 112 are also configured to correspond to the rotation of the output shaft 111 in the positive direction. Specifically, the fan 112 is configured as a centrifugal fan having a fan blade shape, inclination, and the like optimized for forward rotation. Therefore, the amount of air generated when the fan 112 is rotationally driven in the reverse direction is smaller than the amount of air generated when the fan 112 is rotationally driven in the forward direction. As described above, in the hammer drill 100, as the rotational drive mode of the electric motor 110, the normal rotation drive mode in which the output shaft 111 of the electric motor 110 is rotationally driven in the normal rotation direction, and the output shaft 111 of the electric motor 110 in the reverse rotation direction. The reverse drive mode that is rotationally driven is switched.

  As shown in FIG. 1, the hand grip 109 is provided so as to extend in the vertical direction intersecting the major axis direction of the hammer bit 119. The hand grip 109 is formed in a cantilever shape in which a base end portion (upper end portion) is connected to the motor housing 103. A trigger 109 a for switching between the ON state and the OFF state of the electric motor 110 is provided on the front side of the hand grip 109 on the base end side of the hand grip 109. In addition, a power cable 109 b for supplying a current from an external power source to the electric motor 110 is provided at the distal end portion of the hand grip 109. For convenience of explanation, with respect to the direction in which the handgrip 109 extends (the vertical direction in FIG. 1), the proximal end side of the handgrip 109 is defined as the upper side of the hammer drill 100 and the distal end side of the handgrip 109 is below the hammer drill 100. Side.

  As shown in FIG. 1, the gear housing 105 is mainly composed of a housing part 106, a bearing support part 107, and a guide support part 108. The housing part 106 forms an outer shell on the front side of the hammer drill 100 (main body housing 101). A cylindrical barrel portion 106a to which the auxiliary handle is detachably mounted is formed at the distal end portion of the housing portion 106. The bearing support portion 107 and the guide support portion 108 are fixedly attached to the inside of the housing portion 106. The bearing support 107 holds a bearing 114 that supports the output shaft 111 of the electric motor 110 and also holds a bearing 118 b that supports the intermediate shaft 116. The guide support portion 108 is disposed in a substantially intermediate region of the gear housing 105 with respect to the longitudinal direction of the hammer drill 100, and supports the front end portion of the guide shaft 170 (see FIG. 3) for guiding the striking mechanism portion. As shown in FIG. 3, the rear end portion of the guide shaft 170 is supported by the bearing support portion 107.

  As shown in FIG. 1, the gear housing 105 accommodates the motion conversion mechanism 120, the striking element 140, the rotation transmission mechanism 150, the tool holder 159, and the clutch mechanism 180. The rotation output of the electric motor 110 is transmitted to the motion converting mechanism 120 via the clutch mechanism 180, converted into a linear motion by the motion converting mechanism 120, and then transmitted to the striking element 140, whereby the striking element 140 is transmitted to the tool holder. The hammer bit 119 held at 159 is linearly driven in the major axis direction. The hammer bit 119 performs a striking work (also referred to as a hammer work) in which the hammer bit 119 strikes the workpiece by linear driving of the hammer bit 119 in the long axis direction. The rotation output of the electric motor 110 is transmitted to the hammer bit 119 after being decelerated by the rotation transmission mechanism 150, and the hammer bit 119 is rotationally driven in the circumferential direction around the major axis direction. As the hammer bit 119 is driven to rotate, the hammer bit 119 performs a drilling operation (also referred to as a drill operation) on the workpiece.

  An intermediate shaft 116 that is rotationally driven by the electric motor 110 is attached to the gear housing 105. The intermediate shaft 116 is rotatably held with respect to the gear housing 105 via a front bearing 118 a attached to the housing portion 106 and a rear bearing 118 b attached to the bearing support portion 107. The intermediate shaft 116 is held so as not to move in the axial direction of the intermediate shaft 116 (the longitudinal direction of the hammer drill 100) with respect to the gear housing 105. A clutch mechanism 180 driven by the electric motor 110 is provided at the rear end portion of the intermediate shaft 116.

[Configuration of striking mechanism]
As shown in FIG. 2, the striking mechanism unit that drives the hammer bit 119 in order for the hammer bit 119 to perform striking work is configured mainly by the motion conversion mechanism 120, the striking element 140, and the tool holder 159. The striking mechanism portion configured by the motion conversion mechanism 120, the striking element 140, and the tool holder 159 is an implementation configuration example corresponding to the “striking drive mechanism” in the present invention. The motion conversion mechanism 120 includes a rotating body 123 arranged coaxially with the intermediate shaft 116, a swinging shaft 125 attached to the rotating body 123, a piston 127 connected to the tip of the swinging shaft 125, a tool While constituting the rear region of the holder 159, the cylinder 129 that houses the piston 127 and the holding member 130 that holds the rotating body 123 and the cylinder 129 are mainly configured.

  As shown in FIG. 2, the rotating body 123 is provided on the outer periphery of the clutch sleeve 190 of the clutch mechanism 180. The rotating body 123 is spline-coupled with the clutch sleeve 190, rotates together with the clutch sleeve 190, and slides with respect to the clutch sleeve 190 in the axial direction of the clutch sleeve 190 (the longitudinal direction of the hammer drill 100). It is configured. That is, the rotating body 123 is movable between the front position and the rear position with respect to the clutch sleeve 190. A coil spring 124 is provided between the rotating body 123 and the clutch sleeve 190 so as to be coaxial with the clutch sleeve 190. The front end portion of the coil spring 124 abuts on a metal ring spring attached to the inside of the rotating body 123, and the rear end portion of the coil spring 124 abuts on a step portion (shoulder portion) of the clutch sleeve 190. Thus, the coil spring 124 biases the rotating body 123 forward and biases the clutch sleeve 190 rearward. FIG. 2 shows a state where the rotating body 123 is not driven (also referred to as a non-driven state), and the rotating body 123 is located at the front position. The front position of the rotating body 123 is defined by a ring-shaped stopper 190 a attached to the front end portion of the clutch sleeve 190.

  As shown in FIG. 2, the rotating body 123 is supported by a rotating body holding part 131 that constitutes the holding member 130 via a bearing 123 a. The rotating body holding part 131 is formed in a substantially cylindrical shape so as to hold the rotating body 123. The intermediate shaft 116 passes through the rotating body 123 and the clutch sleeve 190 in a non-contact state. Accordingly, the rotating body 123 is held by the rotating body holding portion 131 together with the clutch sleeve 190 so as to be separated from the outer peripheral surface of the intermediate shaft 116 in the radial direction of the intermediate shaft 116. The rotating body 123 is movable relative to the intermediate shaft 116 in the axial direction of the intermediate shaft 116 (the longitudinal direction of the hammer drill 100) together with the rotating body holding portion 131.

  As shown in FIG. 2, the swing shaft 125 is disposed on the outer peripheral portion of the rotating body 123 and extends upward from the rotating body 123. A bottomed cylindrical piston 127 is rotatably connected to a tip end (upper end) of the swing shaft 125. This bottomed cylindrical piston 127 is an implementation configuration example corresponding to the “cylinder” in the present invention. Further, the piston 127 is relatively movable in the axial direction of the swing shaft 125. Therefore, when the rotation of the intermediate shaft 116 is transmitted and the rotating body 123 is driven to rotate, the swing shaft 125 attached to the rotating body 123 is swung in the front-rear direction of the hammer drill 100 (front-rear direction in FIG. 2). As a result, the piston 127 is reciprocated linearly in the longitudinal direction of the hammer drill 100 in the cylinder 129. The rocking shaft 125 is an implementation configuration example corresponding to the “cylinder driving mechanism” in the present invention. Moreover, the cylinder 129 is an implementation structural example corresponding to the "holding part" in this invention.

  As shown in FIG. 2, the rear end portion of the cylinder 129 is held via a bearing 129 a by a cylinder holding portion 132 that constitutes the holding member 130. The cylinder holding part 132 is formed in a substantially cylindrical shape so as to hold the cylinder 129. A holding member 130 is configured as a single member integrally connected to the cylinder holding portion 132 and the rotating body holding portion 131. Specifically, the rotating body holding part 131 and the cylinder holding part 132 are connected and fixed in the vertical direction. The holding member 130 keeps the distance between the rotating body 123 (the swing shaft 125) and the cylinder 129 constant. Accordingly, the rotating body 123, the swing shaft 125 connected to the rotating body 123, and the piston 127 connected to the swing shaft 125 are axial with respect to the intermediate shaft 116 (the longitudinal direction of the hammer drill 100). ), The cylinder 129 similarly moves in the axial direction of the intermediate shaft 116. That is, an assembly body (also referred to as a motion conversion mechanism assembly) in which the constituent elements of the motion conversion mechanism 120 are integrally held (connected) by the holding member 130 is formed.

  As shown in FIG. 2, the striking element 140 is mainly composed of a striker 143 as a striker slidably disposed in the piston 127 and an impact bolt 145 disposed in front of the striker 143 and colliding with the striker 143. It is configured. The space inside the piston 127 behind the striker 143 is defined as an air chamber 127a that functions as an air spring.

  When the piston 127 is moved in the front-rear direction by the swing of the swing shaft 125, the air pressure in the air chamber 127a fluctuates, and the striker 143 slides in the piston 127 in the front-rear direction of the hammer drill 100 by the action of the air spring. Move. When the striker 143 is moved forward, the striker 143 collides with the impact bolt 145, and the impact bolt 145 collides with the hammer bit 119 held by the tool holder 159. As a result, the hammer bit 119 is moved forward to perform the hammering operation on the workpiece.

  As shown in FIG. 2, the tool holder 159 is a substantially cylindrical member and is integrally connected to the cylinder 129 in a coaxial manner. In the rear end region of the tool holder 159 connected to the cylinder 129, a bearing 129b is disposed outside the cylinder 129. The bearing 129b is held by a cylindrical bearing case 129c. The bearing case 129 c is provided to be slidable in the front-rear direction with respect to the barrel portion 106 a of the housing portion 106. Therefore, the tool holder 159 and the cylinder 129 are slidable in the front-rear direction via the bearing 129b and the bearing case 129c with respect to the barrel portion 106a, and are supported so as to be rotatable around the axial direction. The tool holder 159 and the cylinder 129 are held by a cylinder holding part 132 (holding member 130). Therefore, the holding member 130 forms an assembly (also referred to as a striking mechanism assembly) in which the motion conversion mechanism 120, the striking element 140, and the tool holder 159 are integrally connected.

[Relationship between striking mechanism and gear housing]
The hitting mechanism assembly is held movably in the front-rear direction of the hammer drill 100 (long axis direction of the hammer bit 119) with respect to the gear housing 105. Specifically, as shown in FIGS. 3 and 5, four guide shafts 170 are attached to the bearing support portion 107 and the guide support portion 108. That is, a pair of left and right guide shafts 170 are provided above and below the central axis of the piston 127, respectively. As shown in FIG. 5, the left and right guide shafts 170 are disposed symmetrically with respect to a plane extending in the vertical direction of the hammer drill 100 including the central axis of the piston 127. As shown in FIG. 3, the guide shaft 170 is disposed so as to extend in parallel to the major axis direction of the hammer bit 119. The guide shaft 170 is formed as a long member having a circular cross section, but may be a long member having a polygonal cross section.

  As shown in FIG. 3, through holes corresponding to the four guide shafts 170 are formed in the cylinder holding part 132 of the holding member 130, and the guide shaft 170 passes through and holds the cylinder holding part 132. Therefore, the holding member 130 is slidably held along the guide shaft 170 in the front-rear direction by the guide shaft 170 attached to the bearing support portion 107 and the guide support portion 108.

  As shown in FIGS. 3 and 5, two coil springs 171 are provided behind the cylinder holding portion 132 along the outer peripheral surface of the guide shaft 170 so as to be coaxial with the two lower guide shafts 170. ing. The front end of the coil spring 171 is in contact with the cylinder holding portion 132, and the rear end of the coil spring 171 is in contact with the bearing support portion 107. That is, the coil spring 171 is disposed between the motion conversion mechanism 120 that is a component of the striking mechanism and the gear housing 105. The coil spring 171 normally biases the cylinder holding portion 132 forward. That is, the striking mechanism (the motion conversion mechanism 120, the striking element 140, and the tool holder 159) is disposed at the front position shown in FIG. 1 by the urging force of the coil spring 171.

  As shown in FIG. 2, when the striking mechanism (the motion converting mechanism 120, the striking element 140, and the tool holder 159) is biased by the coil spring 171, the tool holder is interposed via the bearing 129b. A bearing case 129c holding 159 (cylinder 129) abuts on the barrel portion 106a to restrict the forward movement of the tool holder 159 (blow mechanism portion).

[Configuration of clutch mechanism]
The hitting mechanism is driven by the electric motor 110 via the clutch mechanism 180. The clutch mechanism 180 is configured to be switched between a power transmission state and a power non-transmission state. Therefore, when the clutch mechanism 180 is in the power transmission state, the motion conversion mechanism 120 is driven, and the hammering operation is performed by the hammering element 140 hitting the hammer bit 119. That is, the torque of the electric motor 110 is transmitted to the motion conversion mechanism 120 via the clutch chrysanthemum 180. As shown in FIGS. 2 to 5, the clutch mechanism 180 is mainly composed of a drive cylinder 181, a lock sleeve 185, a clutch sleeve 190, and a roller 195. This clutch mechanism 180 is an implementation configuration example corresponding to the “clutch mechanism” in the present invention.

  The drive cylinder 181 is a cylindrical member having a circular cross section on the inside, and a driven gear 182 that engages with the pinion gear 113 is formed on the outer peripheral portion. The drive cylinder 181 is fixed coaxially to the intermediate shaft 116. Accordingly, the drive cylinder 181 and the intermediate shaft 116 are integrally rotated by the output shaft 111 of the electric motor 110. Similarly to the pinion gear 113, the driven gear 182 is formed as a helical gear. Due to the engagement of the helical gear, noise during rotation transmission between the pinion gear 113 and the driven gear 182 is suppressed.

  The lock sleeve 185 is disposed coaxially with the drive cylinder 181 inside the drive cylinder 181. The lock sleeve 185 is supported so as to be rotatable relative to the drive cylinder 181 through a bearing 183 provided inside the drive cylinder 181. The lock sleeve 185 is disposed so as to be separated from the intermediate shaft 116 in the radial direction of the intermediate shaft 116.

  As shown in FIG. 5, the lock sleeve 185 has a substantially polygonal cross section on the outside. In the present embodiment, the lock sleeve 185 is formed in a substantially hexagonal column shape having a substantially hexagonal cross section. Corresponding to each side of the hexagon, four roller engaging portions 186 with which the rollers 195 can be engaged and two retainer engaging portions 187 are provided. The roller engaging portion 186 is configured by four planes each parallel to the central axis of the lock sleeve 185. Note that the two opposing surfaces are formed parallel to each other.

  As shown in FIGS. 4 and 5, the front end portion of each retainer engaging portion 187 is provided with an inclined portion 187 a configured with an inclined surface inclined with respect to the central axis of the lock sleeve 185. The two inclined portions 187 a are formed symmetrically with respect to the central axis of the lock sleeve 185. In other words, the two inclined portions 187 a are configured as lead surfaces formed along the circumferential direction around the axial direction of the lock sleeve 185, and the outer diameter line of the retainer engaging portion in a cross section orthogonal to the central axis of the lock sleeve 185. Tilt at the same angle. That is, the two inclined portions 187a are formed in a double spiral shape.

  As shown in FIGS. 4 and 5, the clutch sleeve 190 is coaxial with the intermediate shaft 116 and is spaced from the outer peripheral surface of the intermediate shaft 116. The clutch sleeve 190 has a retainer portion 191 that holds the roller 195 at the rear end portion in the axial direction. The retainer portion 191 has a substantially cup shape, and is disposed coaxially with the drive cylinder 181 inside the drive cylinder 181. The retainer portion 191 has a first side wall 192 and a second side wall 193 that face the inner wall of the drive cylinder 181.

  As shown in FIG. 4, the first side wall 192 and the second side wall 193 are formed so as to extend (project) rearward in the axial direction (front-rear direction) of the clutch sleeve 190. As shown in FIG. 5, two pairs of first side walls 192 and a pair of second side walls 193 are formed across the central axis of the retainer portion 191. In other words, the second side wall 193 is disposed between the two first side walls 192 with respect to the circumferential direction of the retainer portion 191. With respect to the circumferential direction of the retainer 191, a roller holding part for holding the roller 195 is provided between the first side wall 192 and the second side wall 193 as a predetermined space. Accordingly, the retainer unit 191 holds the four rollers 195 between the first side wall 192 and the second side wall 193.

  Further, as shown in FIGS. 4 and 5, the front end portion of the second side wall 193 has an inclined portion 193 a configured by an inclined surface inclined with respect to the central axis line of the retainer portion 191 (the rotational axis line of the clutch sleeve 190). Is provided. The inclined portions 193 a formed on the two second side walls 193 are formed point-symmetrically with respect to the central axis of the retainer portion 191. In other words, the two inclined portions 193 a are configured as lead surfaces formed along the circumferential direction of the retainer portion 191, and have the same angle with respect to the outline of the retainer portion 191 in a cross section orthogonal to the central axis of the retainer portion 191. It is formed to be inclined at. That is, the two inclined portions 193a are formed in a double spiral shape.

  The inclined portion 193a is inclined similarly to the inclined portion 187a of the lock sleeve 185, and can be engaged (contacted) with the inclined portion 187a. That is, as the lock sleeve 185 moves in the axial direction (front-rear direction), the inclined portion 193a comes into contact with and separates from the inclined portion 187a. As shown in FIG. 4, in the non-driving state, the clutch sleeve 190 is disposed forward, and the inclined portion 193a and the inclined portion 187a are separated from each other. At this time, as shown in FIG. 5, the rollers 195 are arranged corresponding to the center positions of the respective roller engaging portions 186 and are not sandwiched between the lock sleeve 185 and the drive cylinder 181. A position where the roller 195 shown in FIG. 5 is held so as not to be sandwiched is also referred to as a neutral position or a rotation non-transferable position.

[Configuration of rotation transmission mechanism]
As shown in FIG. 2, the rotation transmission mechanism 150 includes a first gear 151 disposed coaxially with the intermediate shaft 116, and a gear reduction gear including a plurality of gears such as a second gear 153 engaged with the first gear 151. The mechanism is the main component. The second gear 153 is attached to the cylinder 129 and transmits the rotation of the first gear 151 to the cylinder 129. As the cylinder 129 is rotated, the tool holder 159 connected integrally with the cylinder 129 is rotated. Thereby, the hammer bit 119 held by the tool holder 159 is rotationally driven. This rotation transmission mechanism 150 is an implementation configuration example corresponding to the “rotation drive mechanism” in the present invention.

  As shown in FIG. 2, the first gear 151 is a substantially cylindrical member, and is arranged in a loose shape with respect to the intermediate shaft 116. The first gear 151 has a spline engaging portion 152 and can be engaged with a spline groove formed in the intermediate shaft 116. Therefore, the first gear 151 is configured to be able to rotate integrally with the intermediate shaft 116 and to be slidable in the front-rear direction with respect to the intermediate shaft 116. That is, in a state where the first gear 151 is disposed in the front (front position), the spline engaging portion 152 of the first gear 151 does not engage with the intermediate shaft 116, and the rotation of the intermediate shaft 116 is not performed with the first gear 151. Is not transmitted, and the first gear 151 is not rotated. On the other hand, in a state where the first gear 151 is disposed rearward (backward position), the spline engaging portion 152 of the first gear 151 is engaged with the intermediate shaft 116, and the rotation of the intermediate shaft 116 is transmitted to the first gear 151. The first gear 151 rotates integrally with the intermediate shaft 116. FIG. 2 shows a state in which the first gear 151 is located at the rear position.

  When the operator operates the switching mechanism 198 (mode switching dial) shown in FIG. 5, the first gear 151 is switched between the front position, the rear position, and an intermediate position between the front position and the rear position. That is, the first gear 151 is held at the front position, the rear position, or the intermediate position by the holding member 155. Further, the switching mechanism 198 has a striking mechanism unit movement restriction unit 156 that contacts the holding member 130 and regulates the movement of the tool holder 159 and the cylinder 129 to the rear side in a state where the first gear 151 is located at the rear position. Have. That is, the striking mechanism portion movement restricting portion 156 is in contact with the tool holder 159 and the cylinder 129 to restrict the movement of the tool holder 159 and the cylinder 129 to the rear, and the tool holder 159 and the cylinder 129. The impact mechanism unit movement allowable state in which the tool holder 159 and the cylinder 129 are allowed to move rearward is switched. When the first gear 151 is located at the front position, torque transmission from the intermediate shaft 116 to the first gear 151 is interrupted. At this time, the rotation of the first gear 151 is restricted by a restriction member (not shown) that engages with the first gear 151 and restricts the rotation of the first gear 151. When the first gear 151 is located at the rear position, torque transmission from the intermediate shaft 116 to the first gear 151 is allowed. At this time, the restricting member does not engage with the first gear 151, thereby allowing the rotation of the first gear 151. When the first gear 151 is located at the intermediate position, torque transmission from the intermediate shaft 116 to the first gear 151 is interrupted. At this time, the restricting member does not engage with the first gear 151, thereby allowing the rotation of the first gear 151.

  In a state where the first gear 151 is located at the rear position and is switched to the percussion mechanism portion movement permissible state, the rotation transmission mechanism 150 and the percussion mechanism portion are driven, thereby performing a hammer drill operation. In other words, the drive mode is switched to the hammer drill mode by the switching mechanism 198. This hammer drill mode is an implementation configuration example corresponding to the “striking rotation drive mode” in the present invention. In addition, when the first gear 151 is located at the rear position and is switched to the striking mechanism unit movement restricted state, the rotation transmission mechanism 150 is driven, but the striking mechanism unit is not driven (the striking mechanism unit is powered). Is not transmitted), thereby drilling. In other words, the drive mode is switched to the drill mode by the switching mechanism 198. This drill mode is an implementation configuration example corresponding to the “rotation drive mode” in the present invention. On the other hand, when the first gear 151 is located at the front position, the striking mechanism unit movement restricting unit 156 does not contact the tool holder 159 and the cylinder 129 and allows the tool holder 159 and the cylinder 129 to move rearward. To do. That is, when the first gear 151 is located at the front position, the rotation transmission mechanism 150 is not driven (power is not transmitted to the rotation transmission mechanism), and the striking mechanism is driven, thereby performing a hammering operation. In other words, the drive mode is switched to the hammer mode by the switching mechanism 198. This hammer mode is an implementation configuration example corresponding to the “hitting drive mode” in the present invention. When the first gear 151 is located at the intermediate position, torque transmission from the intermediate shaft 116 to the first gear 151 is interrupted, but the rotation of the first gear 151 is allowed. Therefore, rotation of the tool holder 159 connected to the first gear 151 is also allowed. Therefore, the operator can manually rotate the cold chisel or scaling chisel as the tip tool held by the tool holder 159 to determine the angular position. In addition, about the detail of the structure of the switching mechanism 198, description is abbreviate | omitted for convenience. This switching mechanism 198 is an implementation configuration example corresponding to the “drive mode switching unit” in the present invention.

  The second gear 153 moves in the axial direction of the first gear 151 with respect to the first gear 151 by the movement of the cylinder 129 (tool holder 159) in the front-rear direction, and the second gear 153 is connected to the first gear 151. It is configured to be always engaged.

  When the first gear 151 is rotationally driven, the second gear 153 engaged with the first gear 151 is rotated. Thereby, the tool holder 159 connected to the cylinder 129 is rotationally driven, and the hammer bit 119 held by the tool holder 159 is rotationally driven around the axis. As the hammer bit 119 rotates, the hammer bit 119 drills the workpiece.

[Movement of clutch mechanism when hammer drill is driven]
When the trigger 109a is operated, the hammer drill 100 described above is driven by the electric motor 110 based on the rotation direction selected by the changeover switch 110a, and also converted by the movement based on the drive mode selected by the switching mechanism 198. The mechanism 120, the striking element 140, and the rotation transmission mechanism 150 are driven. Thereby, the hammer bit 119 held by the tool holder 159 is driven, and a predetermined processing operation (hammer operation, hammer drill operation, drill operation) is performed.

[Hammer work, hammer drill work]
When the switching mechanism 198 switches the drive mode to the hammer mode or the hammer drill mode, the rearward movement of the striking mechanism is allowed. When the hammer work or the hammer drill work is performed, the tool holder 159 and the cylinder 129 that hold the hammer bit 119 move backward as shown in FIG. 6 when the hammer bit 119 is pressed against the workpiece. To do. That is, the motion conversion mechanism 120 and the striking element 140 held by the holding member 130 are moved rearward against the urging force of the coil springs 124 and 171 and arranged at the rear position shown in FIG. The position shown in FIG. 6 is also referred to as a first rear position.

  When the motion conversion mechanism 120 is moved backward, the rotating body 123 moves the clutch sleeve 190 backward via the coil spring 124. 7, the inclined portion 193a of the clutch sleeve 190 is engaged with the inclined portion 187a of the lock sleeve 185, and the lock sleeve 185 and the clutch sleeve 190 are brought into contact with the clutch sleeve 190 ( They are rotated in opposite directions around the axis of the locking sleeve 185). As a result, the roller 195 is moved from the neutral position shown in FIG. 5 in the direction (A direction) indicated by the arrow A in the circumferential direction of the lock sleeve 185, and is arranged at the rotation transmission position shown in FIG.

  In the rotation transmission position, the roller 195 is sandwiched between the drive cylinder 181 and the lock sleeve 185. In a state where the rotation direction of the output shaft 111 of the electric motor 110 is switched to the normal rotation direction, the drive cylinder 181 and the lock sleeve 185 rotate integrally in the A direction by the wedge effect of the roller 195. That is, a frictional force is generated between the roller 195 and the drive cylinder 181, and the drive cylinder 181 and the lock sleeve 185 are rotated together using the frictional force. As the lock sleeve 185 rotates, the inclined portion 187a of the lock sleeve 185 contacts the inclined portion 193a of the clutch sleeve 190 to rotate the clutch sleeve 190. As a result, the clutch sleeve 190 is rotated around the axis. That is, the rotation of the output shaft 111 of the electric motor 110 is transmitted to the clutch sleeve 190. This state is the power transmission state of the clutch mechanism 180. As a result, the rotating body 123 is rotationally driven, and the swing shaft 125 is swung in the front-rear direction of the hammer drill 100. That is, the motion conversion mechanism 120 is driven, and thereby the hammer bit 119 is driven linearly by the striking element 140. This roller 195 is an implementation configuration example corresponding to the “transmission member” in the present invention. Moreover, the drive sleeve 181 and the clutch sleeve 190 are implementation structural examples corresponding to the “drive clutch member” and the “driven clutch member” in the present invention, respectively.

  On the other hand, in a state where the rotation direction of the output shaft 111 of the electric motor 110 is switched to the reverse rotation direction, the movement of the motion conversion mechanism 120 causes the roller 195 to move from the neutral position to the rotation transmission position. By the rotation of the cylinder 181 in the B direction, the wedge effect of the roller 195 is canceled. That is, the clutch mechanism 180 is in a power non-transmission state. Therefore, when the output shaft 111 of the electric motor 110 is in the reverse rotation direction, the rotation of the output shaft 111 is not transmitted to the clutch sleeve 190 in the clutch mechanism 180, and the motion conversion mechanism 120 is not driven. As a result, it is possible to avoid performing a hammer operation or a hammer drill operation by driving the output shaft 111 of the electric motor 110 in the reverse direction.

  As described above, when the rotation direction of the output shaft 111 of the electric motor 110 is switched to the normal rotation direction by the changeover switch 110a and the drive mode is changed to the hammer drill mode by the switching mechanism 198, the first gear 151 is engaged with the intermediate shaft 116 to drive the rotation transmission mechanism 150, and the hammer bit 119 is linearly driven in the long axis direction and is rotated about the long axis. Thereby, the hammer drill 100 performs a hammer drill operation. On the other hand, when the rotation direction of the output shaft 111 of the electric motor 110 is switched to the normal rotation direction by the switch 110a and the drive mode is switched to the hammer mode by the switching mechanism 198, the first gear 151 is The rotation of the rotation transmission mechanism 150 is not engaged with the intermediate shaft 116, and the hammer bit 119 is only linearly driven in the long axis direction. Thereby, the hammer drill 100 performs a hammer operation. Note that the clutch mechanism 180 is switched to the power transmission state at the position shown in FIG. 6 when the hammer bit 119 is pressed, but at the time of hammering or hammer drilling, the rotating body 123 has the retainer 191 as shown in FIG. The hammer bit 119 can be further pressed until it contacts. That is, the motion conversion mechanism 120 and the striking element 140 can move further rearward from the first rear position. The position shown in FIG. 9 is also referred to as a rear second position.

  When the hammer bit 119 is released from being pressed against the workpiece, it is moved forward by the biasing force of the coil springs 124 and 171 and the clutch sleeve 190 is allowed to move forward. The clutch sleeve 190 is rotated by the inclined portion 193a being pushed in the circumferential direction by the inclined portion 187a of the lock sleeve 185, and the clutch sleeve 190 is pushed forward by the contact of the inclined surface. Is allowed to move forward, the clutch sleeve 190 is moved forward by the lock sleeve 185. As a result, the roller 195 held by the retainer 191 is moved in the B direction and disposed at the neutral position shown in FIG. 5, and the nipping of the roller 195 by the drive cylinder 181 and the lock sleeve 185 is released. Thereby, the rotation transmission from the drive cylinder 181 to the lock sleeve 185 is interrupted, and the clutch mechanism 180 is in a power non-transmission state, and the hammer operation or the hammer drill operation is completed. As described above, the clutch sleeve 190 holds the roller 195, and when the pressing force is applied (during the striking operation), the function of switching the rotation transmission position of the roller 195 from the neutral position and when the pressing force is released. It has a function of moving the roller 195 to the neutral position by the inclined portion 193a (at the end of the striking work).

[Drilling]
When the drive mode is switched to the drill mode by the switching mechanism 198, the rearward movement of the striking mechanism portion is restricted by the striking mechanism movement restricting portion 156. Therefore, the clutch sleeve 190 is not moved rearward, and the clutch mechanism 180 maintains a power non-transmission state. At this time, the hammer bit 119 is rotationally driven by the rotation transmission mechanism 150, whereby a drilling operation is performed.

[Motion of hammering mechanism when driving hammer drill]
When the hammer bit 119 is pressed against the workpiece and the machining operation is performed, the striking mechanism unit reciprocates the swing shaft 125 in the front-rear direction of the hammer drill 100 as shown in FIGS. 9 and 10. As a result, the hammer drill 100 mainly vibrates in the longitudinal direction of the hammer bit 119 by the driving force that drives the hammer bit 119 and the reaction force that is applied when the hammer bit 119 strikes the workpiece by the driving force. Will occur. Due to the vibration of the hammer drill 100, the striking mechanism moves along the guide shaft 170 in the front-rear direction of the hammer drill 100, and the coil spring 171 is expanded and contracted. At this time, the rotating body 123 moves in the front-rear direction of the hammer drill 100 along the clutch sleeve 190, and the coil spring 124 is expanded and contracted. That is, during the machining operation, the striking mechanism moves between a front position of the striking mechanism shown in FIG. 2 and a second rear position of the striking mechanism shown in FIG. Typically, the hammer mechanism 119 moves between the first rear position shown in FIG. 6 and the second rear position shown in FIG. 9 in consideration of the pressing of the hammer bit 119 against the workpiece during the processing operation. Set to do. The kinetic energy of vibration in the long axis direction of the hammer bit 119 is consumed by the expansion and contraction (elastic deformation) of the coil springs 124 and 171 accompanying the movement of the striking mechanism. Thereby, the vibration of the hammer bit 119 in the major axis direction is reduced. As a result, vibration transmission from the striking mechanism portion to the main body housing 101 is suppressed.

  According to the first embodiment described above, when the hammering operation is performed, the hammer bit 119 is pressed against the workpiece, so that the roller 195 is attached to the rotating drive cylinder 181 with respect to the rotating drive cylinder 181. While moving around the rotation axis, the position of the roller 195 is switched from the neutral position to the rotation transmission position. Therefore, for example, compared to a configuration in which a rotating cam and a stopped cam mesh with each other, wear of each member of the clutch mechanism 180 is reduced by the movement of the roller 195, and the roller 195 is rationally rotated. It is moved to the transmission position.

  At the end of the striking operation, the hammer bit 119 is released and the rollers 195 are reliably moved to the neutral position (non-rotatable position) by the action of the inclined portions 187a and 193a of the clutch mechanism 180.

  In addition, the hammer drill 100 can be driven in the hammer drill mode, the hammer mode, and the drill mode in a state where the rotation direction of the electric motor 110 is switched so that the hammer bit 119 is rotated in the forward direction. On the other hand, when the rotation direction of the electric motor 110 is switched so that the hammer bit 119 is rotated in the reverse direction, the hammer drill 100 is not driven in the hammer drill mode and the hammer mode. The electric motor 110 is set so that the performance is maximized when the hammer bit 119 is driven to rotate in the forward direction. Therefore, when the electric motor 110 is rotated in the direction opposite to the direction in which the hammer bit 119 is rotationally driven in the forward direction, the performance of the electric motor 110 may not be maximized. Driving the hammer bit 119 for a long time in a state where the electric motor 110 is driven in a rotation direction that is not appropriate as described above is assumed to have a large load on the electric motor 110. Therefore, according to the first embodiment, when the electric motor 110 is driven in the reverse rotation direction, the rotation of the electric motor 110 is not transmitted to the motion conversion mechanism 120 and the hammer bit 119 cannot perform a striking work. Is set to On the other hand, for example, the hammer bit 119 may bite into the workpiece during the machining operation, and the hammer bit 119 may be driven to rotate in the reverse direction in order to separate the hammer bit 119 from the workpiece. Therefore, in the first embodiment, the hammer bit 119 is allowed to rotate in the reverse direction, and thus the hammer bit 119 bitten into the workpiece can be separated from the workpiece. That is, the drive in the reverse direction of the electric motor 110 is used not to perform the machining operation by the hammer bit 119 but to return the hammer drill 110 (hammer bit 119) from the abnormal state.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. The hammer drill 200 of the second embodiment is different in clutch mechanism from the hammer drill 100 of the first embodiment. Therefore, components other than the clutch mechanism are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  As shown in FIGS. 11 and 12, the hammer drill 200 has a friction clutch mechanism 280. The clutch mechanism 280 is mainly composed of a drive cylinder 281 and a clutch sleeve 290. This clutch mechanism 280 is an implementation configuration example corresponding to the “clutch mechanism” in the present invention. The drive cylinder 281 and the clutch sleeve 290 are implementation examples corresponding to the “drive clutch member” and the “driven clutch member” in the present invention, respectively.

  As shown in FIG. 12, the drive cylinder 281 is a cylindrical member having an inner circular cross section. Specifically, the inside of the drive cylinder 281 is formed in a truncated cone shape. That is, the drive cylinder 281 includes a drive-side engagement surface 281 a that is inclined with respect to the axis of the intermediate shaft 116. A driven gear (not shown) that engages with the pinion gear 113 is formed on the outer peripheral portion of the drive cylinder 281. The drive cylinder 281 is fixed coaxially to the intermediate shaft 116. Therefore, the drive cylinder 281 and the intermediate shaft 116 are integrally rotated by the output shaft 111 of the electric motor 110.

  As shown in FIG. 12, the clutch sleeve 290 is coaxial with the intermediate shaft 116 and is provided away from the outer peripheral surface of the intermediate shaft 116. The clutch sleeve 290 has a clutch portion 291 at the rear end portion in the axial direction. The clutch portion 291 is formed as a frustoconical clutch shoe. The clutch portion 291 includes a driven side engaging surface 291 a that is inclined with respect to the axis of the intermediate shaft 116. The clutch portion 291 is disposed inside the drive cylinder 281 so that the driven-side engagement surface 291a faces the drive-side engagement surface 281.

  As shown in FIG. 11, the striking mechanism (the motion conversion mechanism 120, the striking element 140, and the tool holder 159) is biased by the coil spring 171 and is positioned at the front position. At this time, a gap is formed between the drive cylinder 281 and the clutch portion 291 as shown in FIG. That is, the non-engaged state of the driving side engaging surface 281a and the driven side engaging surface 291a is maintained. Therefore, the clutch mechanism 280 is maintained in a power non-transmission state in which the transmission of torque from the drive cylinder 281 to the clutch sleeve 290 is interrupted.

  When the hammer mode or the hammer drill mode is selected, the rearward movement of the striking mechanism is allowed as in the first embodiment. That is, when performing a hammer operation or a hammer drill operation, the hammer bit 119 is pressed against the workpiece, and the striking mechanism portion resists the urging force of the coil springs 124 and 171 as shown in FIG. Moved backwards. At this time, as shown in FIG. 14, the clutch sleeve 290 is moved rearward, and the driven side engaging surface 291a abuts on the driving side engaging surface 281a. Accordingly, the clutch sleeve 290 is engaged with the drive cylinder 281, and the torque of the drive cylinder 281 can be transmitted to the clutch sleeve 290 by the frictional force generated between the drive side engagement surface 281 a and the driven side engagement surface 291 a. . That is, the clutch mechanism 280 is configured to transmit torque using a frictional force related to the circumferential direction around the rotation axis. Thus, the clutch mechanism 280 is switched to a power transmission state in which torque transmission from the drive cylinder 281 to the clutch sleeve 290 is permitted.

  Therefore, the rotation of the output shaft 111 of the electric motor 110 is transmitted to the clutch sleeve 290, and thereby the motion conversion mechanism 120 is driven. As a result, the hammer bit 119 is driven linearly by the striking element 140, and a hammer operation or a hammer drill operation is performed according to the selected drive mode.

  When the drill mode is selected, the rearward movement of the striking mechanism is restricted as in the first embodiment. Therefore, the clutch sleeve 290 is not moved rearward, and the clutch mechanism 280 maintains the power non-transmission state. At this time, the hammer bit 119 is rotationally driven by the rotation transmission mechanism 150, whereby a drilling operation is performed.

  According to the second embodiment described above, the clutch sleeve 290 is switched from the front position to the rear position with respect to the drive cylinder 281 by pressing the hammer bit 119 against the workpiece when performing the striking work. It is done. Therefore, the clutch mechanism 280 can be switched from the power non-transmission state to the power transmission state using the force with which the hammer bit 119 is pressed against the workpiece during the hammer operation or the hammer drill operation.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. The hammer drill 300 of the third embodiment is different in clutch mechanism from the hammer drill 100 of the first embodiment. Therefore, components other than the clutch mechanism are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  As shown in FIGS. 15 to 18, the hammer drill 300 has a friction clutch mechanism 380. The clutch mechanism 380 is exercised mainly by a drive cylinder 381, a driven sleeve 390, and a plurality of friction plates 385 and 395. This clutch mechanism 380 is an implementation configuration example corresponding to the “clutch mechanism” in the present invention.

  As shown in FIG. 16, the drive cylinder 381 is a cylindrical member having a substantially circular cross section on the inside. The drive cylinder 381 includes a drive plate holding portion 382 in which a plurality of friction plates 385 and 395 are disposed. The drive plate holding portion 382 is formed in a cylindrical shape coaxial with the axis of the intermediate shaft 116. Further, a shoulder portion 383 that protrudes from the drive plate holding portion 382 toward the radially inner side of the drive cylinder 381 is formed behind the drive plate holding portion 382.

  As shown in FIG. 17, concave portions 382 a that engage with the convex portions 385 a of the drive friction plate 385 are formed at regular intervals in the circumferential direction on the inner peripheral surface of the drive plate holding portion 382. In addition, the recessed part 382a of the drive plate holding | maintenance part 382 is comprised so that the driven friction plate 395 may not be engaged, as shown in FIG.

  As shown in FIG. 16, the driven sleeve 390 is coaxial with the intermediate shaft 116 and is provided away from the outer peripheral surface of the intermediate shaft 116. The driven sleeve 390 has a driven plate holding portion 391 at the rear end portion in the axial direction. A plurality of friction plates 385 and 395 are arranged outside the driven plate holding portion 391. That is, the friction plates 385 and 395 are disposed between the driven plate holding portion 391 and the drive plate holding portion 382. In addition, a shoulder portion 392 that protrudes from the driven plate holding portion 391 toward the radially outer side of the driven sleeve 390 is formed in front of the driven plate holding portion 391.

  As shown in FIG. 18, convex portions 391a that engage with the concave portions 395a of the driven friction plate 395 are formed on the outer peripheral surface of the driven plate holding portion 391 at regular intervals in the circumferential direction. In addition, the convex part 391a of the driven plate holding | maintenance part 391 is comprised so that it may not engage with the drive friction plate 385, as shown in FIG.

  As shown in FIG. 16, three drive friction plates 385 and three driven friction plates 395 are arranged in the axial direction of the drive cylinder 381. With respect to the axial direction of the drive cylinder 381, two drive friction plates 385 are disposed between the three driven friction plates 395, and one drive friction plate 385 is provided between the driven friction plate 395 and the shoulder portion 392 of the driven sleeve 390. Arranged between. Further, with respect to the axial direction of the drive cylinder 381, two driven friction plates 395 are disposed between the three drive friction plates 385, and one driven friction plate 395 is a shoulder portion of the drive friction plate 385 and the drive cylinder 381. 383. Note that the numbers of the drive friction plates 385 and the driven friction plates 395 are set according to the frictional force required for the clutch mechanism 380 to transmit torque.

  As shown in FIG. 17, the drive friction plate 385 is a metal disk-shaped plate. A convex portion 385 a is formed on the outer peripheral portion of the drive friction plate 385. The convex portion 385a engages with the concave portion 382a of the drive cylinder 381 (drive plate holding portion 382), and the drive friction plate 385 is held by the drive cylinder 381. Thus, the drive friction plate 385 is configured to be rotatable integrally with the drive cylinder 381. This drive cylinder 381 is an implementation structural example corresponding to the "drive clutch member" in this invention.

  As shown in FIG. 18, the driven friction plate 395 is a metal disk-like plate. A recessed portion 395 a is formed in the inner peripheral portion of the driven friction plate 395. The recessed portion 395 a engages with the convex portion 391 a of the driven sleeve 390 (driven plate holding portion 391), and the driven friction plate 395 is held by the driven sleeve 390. Accordingly, the driven friction plate 395 is configured to be rotatable integrally with the driven sleeve 390. This driven sleeve 390 is an implementation configuration example corresponding to the “driven clutch member” in the present invention.

  As shown in FIG. 15, the striking mechanism (the motion conversion mechanism 120, the striking element 140, and the tool holder 159) is biased by the coil spring 171 and is positioned at the front position. At this time, as shown in FIG. 16, the friction plates 385 and 395 are held with a gap in the axial direction of the drive cylinder 381 between the shoulder portion 383 of the drive cylinder 381 and the shoulder portion 392 of the driven sleeve 390. The Therefore, no frictional force is generated between the friction plates 385 and 395. Therefore, the clutch mechanism 380 is maintained in a power non-transmission state in which the transmission of torque from the drive cylinder 381 to the driven sleeve 390 is interrupted.

  When the hammer mode or the hammer drill mode is selected, the rearward movement of the striking mechanism is allowed as in the first embodiment. That is, when performing a hammer operation or a hammer drill operation, the hammer bit 119 is pressed against the workpiece, and the striking mechanism portion resists the urging force of the coil springs 124 and 171 as shown in FIG. Moved backwards. At this time, as shown in FIG. 20, the driven sleeve 390 is moved backward, the drive friction plate 385 and the driven friction plate 395 come into contact with each other, and the shoulder portion 383 of the drive cylinder 380 and the shoulder portion 392 of the driven sleeve 390 are Sandwiched between. As a result, a frictional force is generated between the driving friction plate 385 and the driven friction plate 395, and the driven friction plate 395 can rotate integrally with the driving friction plate 385. That is, the clutch mechanism 380 is configured to transmit torque using a frictional force related to the rotation axis direction. As a result, the clutch mechanism 380 is switched to a power transmission state in which torque transmission from the drive cylinder 381 to the driven sleeve 390 is permitted. The driving friction plate 385 and the driven friction plate 395 are an exemplary configuration corresponding to the “transmission member” in the present invention.

  Therefore, the rotation of the output shaft 111 of the electric motor 110 is transmitted to the driven sleeve 390, thereby driving the motion conversion mechanism 120. As a result, the hammer bit 119 is driven linearly by the striking element 140, and a hammer operation or a hammer drill operation is performed according to the selected drive mode.

  When the drill mode is selected, the rearward movement of the striking mechanism is restricted as in the first embodiment. Therefore, the driven sleeve 390 is not moved rearward, and the clutch mechanism 380 maintains the power non-transmission state. At this time, the hammer bit 119 is rotationally driven by the rotation transmission mechanism 150, whereby a drilling operation is performed.

  According to the third embodiment described above, the driven sleeve 390 is switched from the front position to the rear position with respect to the drive cylinder 381 by pressing the hammer bit 119 against the workpiece when performing the striking work. It is done. Therefore, the clutch mechanism 380 can be switched from the power non-transmission state to the power transmission state by using the force with which the hammer bit 119 is pressed against the workpiece during the hammering operation or the hammer drilling operation.

  Further, according to the first to third embodiments described above, at the time of the striking work, the motion conversion mechanism 120, the striking element 140, and the tool holder 159 as the striking mechanism are integrated to form the gear housing 105 (main body housing). 101). At this time, the striking force of the hammer bit 119 during striking work is caused by the elastic deformation of the coil spring 171 disposed between the striking mechanism and the gear housing 105 and the coil spring 124 disposed between the striking mechanism and the clutch sleeve 190. Further, the vibration in the major axis direction of the hammer bit 119 generated in the striking mechanism portion by the reaction force from the workpiece is reduced. Thereby, vibration transmission from the striking mechanism portion to the main body housing 101 (gear housing 105) is suppressed. Therefore, the operability of the hammer drill 100 is improved.

  Further, according to the first to third embodiments, the tool holder 159 and the cylinder 129 are integrally fixed, and the cylinder 129 is held by the holding member 130. Even if the hammer bit 119 moves in the major axis direction, the distance between the motion conversion mechanism 120 and the striking element 140 is maintained constant. Therefore, the striking force by the hammer bit 119 does not fluctuate.

  Further, according to the first to third embodiments, the clutch mechanisms 180, 280, 380 transmit the torque using the frictional force acting in the circumferential direction around the rotation axis of the drive sleeves 181, 281, 381. By using the frictional force, wear of components constituting the clutch mechanism is suppressed compared to a so-called cam clutch that transmits torque by mechanical engagement of clutch teeth.

  In the above first to third embodiments, the hand grip 109 is formed in a cantilever shape extending downward from the motor housing 103, but is not limited thereto. For example, the hand grip 109 may be formed in a loop shape so that the distal end portion of the hand grip 109 is further connected to the motor housing 103.

  Moreover, in the above 1st-3rd embodiment, although the output shaft 111 of the electric motor 110 was arrange | positioned in parallel with the major axis of the hammer bit 119, it is not restricted to this. For example, the output shaft 111 of the electric motor 110 may be disposed so as to intersect the long axis of the hammer bit 119. In this case, the output shaft 111 and the intermediate shaft 116 are preferably engaged via a bevel gear. The output shaft 111 is preferably arranged so as to be orthogonal to the long axis of the hammer bit 119.

  Moreover, in the above 1st-3rd embodiment, although the pinion gear 113 and the driven gear 117 were formed as a helical gear, it is not restricted to this. That is, for example, a spur gear or a bevel gear may be used as the gear.

  In the first to third embodiments described above, the clutch mechanism 180 is a mechanical clutch mechanism that moves the roller 105 when the hammering mechanism 119 moves in the front-rear direction of the hammer drill 100 by pressing the hammer bit 119. Although applied, it is not limited to this. For example, an electromagnetic clutch may be applied as the clutch mechanism. In this case, a controller is provided, and the controller may control the electromagnetic clutch based on the rotational drive mode of the electric motor 110 and the drive mode of the hammer bit 119.

In view of the gist of the above invention, the impact tool according to the present invention can be configured in the following manner. 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 clutch mechanism transmits torque only by the frictional force between the driving clutch member and the driven clutch member.
(Aspect 2)
The clutch mechanism is a friction around the rotation axis of the drive clutch member that is generated between the drive clutch member and the driven clutch member due to a force in the long axis direction of the tip tool for pressing the tip tool against the workpiece. Torque is transmitted by force.
(Aspect 3)
The cylinder drive mechanism is
A rocking member disposed on a predetermined intermediate shaft and rocked in the major axis direction of the tip tool by rotation of the intermediate shaft;
The clutch mechanism is coaxial with the intermediate shaft and is disposed between the intermediate shaft and the output shaft of the motor.
(Aspect 4)
A second intermediate shaft that is rotationally driven by the motor;
A rotation drive mechanism that transmits the rotation of the second intermediate shaft to the tip tool and drives the tip tool to rotate;
The second intermediate shaft is coaxial with the intermediate shaft, is disposed so as to penetrate the intermediate shaft, and is coupled to the drive clutch member so as to rotate integrally with the drive clutch member. Yes.
(Aspect 5)
A housing for accommodating the impact driving mechanism;
A first elastic element disposed in an intervening manner between the striking drive mechanism and the housing;
A second elastic element disposed in an intervening manner between the impact driving mechanism and the intermediate shaft,
The intermediate shaft is arranged so as to extend in parallel with the major axis direction of the tip tool,
In a state where the urging force of the first elastic element is applied, the striking drive mechanism is movable in the major axis direction with respect to the housing, and in a state where the urging force of the second elastic element is applied, The striking drive mechanism is configured to be slidable in the long axis direction of the tip tool with respect to the intermediate shaft.
(Aspect 6)
When the tip tool is pressed against the workpiece during the striking work, the urging force of the first elastic element and the second elastic element acts on the striking drive mechanism,
In a state where the urging force is applied, the impact drive mechanism is configured to reciprocate in the long axis direction of the tip tool so that vibration generated during impact work is prevented from being transmitted to the housing. .

(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 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 hammer drill 100 is an example of a configuration corresponding to the “striking tool” of the present invention.
The electric motor 110 is an example of a configuration corresponding to the “motor” of the present invention.
The output shaft 111 is an example of a configuration corresponding to the “output shaft” of the present invention.
The hammer bit 119 is an example of a configuration corresponding to the “tip tool” of the present invention.
The motion conversion mechanism 120 is an example of a configuration corresponding to the “blow drive mechanism” of the present invention.
The striking element 140 is an example of a configuration corresponding to the “striking drive mechanism” of the present invention.
The rotation transmission mechanism 150 is an example of a configuration corresponding to the “rotation drive mechanism” of the present invention.
The clutch mechanism 180 is an example of a configuration corresponding to the “clutch mechanism” of the present invention.
The drive cylinder 181 is an example of a configuration corresponding to the “drive clutch member” of the present invention.
The clutch sleeve 190 is an example of a configuration corresponding to the “driven clutch member” of the present invention.
The roller 195 is an example of a configuration corresponding to the “transmission member” of the present invention.
The switching mechanism 198 is an example of a configuration corresponding to the “drive mode switching unit” of the present invention.

DESCRIPTION OF SYMBOLS 100 Hammer drill 101 Main body housing 103 Motor housing 105 Gear housing 106 Housing part 106a Barrel part 107 Bearing support part 108 Guide support part 109 Hand grip 109a Trigger 109b Power cable 110 Electric motor 110a Changeover switch 111 Output shaft 112 Motor cooling fan 113 Pinion gear 114 Bearing 115 Bearing 116 Intermediate shaft 117 Driven gear 118a Bearing 118b Bearing 119 Hammer bit 120 Motion conversion mechanism 123 Rotating body 123a Bearing 124 Coil spring 125 Oscillating shaft 127 Piston 127a Air chamber 129 Cylinder 129a Bearing 129b Bearing 129c Bearing case 130 Holding member 131 Rotating body holding member 132 Cylinder holding Holding portion 140 Strike element 143 Strike 145 Impact bolt 150 Rotation transmission mechanism 151 First gear 152 Spline engagement portion 153 Second gear 155 Holding member 156 Stroke mechanism portion movement restriction portion 159 Tool holder 170 Guide shaft 171 Coil spring 180 Clutch mechanism 181 Drive cylinder 182 Driven gear 183 Bearing 185 Lock sleeve 186 Roller engaging portion 187 Retainer engaging portion 187a Inclined portion 190 Clutch sleeve 190a Stopper 191 Retainer portion 192 First side wall 193 Second side wall 193a Inclined portion 195 Roller 198 Switching mechanism 200 Hammer drill 280 Clutch mechanism 281 Drive cylinder 281a Drive side engagement surface 290 Clutch sleeve 291 Clutch portion 291a Driven side engagement surface 300 Hammer drill 380 Latch mechanism 381 Drive cylinder 382 Drive plate holding portion 382a Recessed portion 383 Shoulder portion 385 Drive friction plate 385a Protruding portion 390 Driven sleeve 391 Driven plate holding portion 391a Convex portion 392 Shoulder portion 395 Driven friction plate 395a Recessed portion

Claims (6)

The tip tool removably mounted on the tip region of the tool body is driven in the long axis direction of the tip tool without being driven to rotate around the long axis direction of the tip tool, and the workpiece is turned. A striking tool with a striking drive mode to perform,
A motor having an output shaft;
An impact driving mechanism for driving the tip tool in the longitudinal direction;
A clutch mechanism capable of transmitting and interrupting a driving force to the tip tool,
The impact driving mechanism includes a cylinder, a holding portion that holds the cylinder, and a cylinder driving mechanism that reciprocates the cylinder,
The tip tool is configured to be driven in the long axis direction by reciprocation of the cylinder,
The clutch mechanism includes a drive clutch member that is rotationally driven by the output shaft, and a driven clutch member that is rotationally driven by transmission of torque of the drive clutch member.
The driven clutch member is between a torque transmission position where torque is transmitted from the driving clutch member to the driven clutch member and a torque transmission cutoff position where transmission of torque from the driving clutch member to the driven clutch member is blocked. Is configured to be movable,
When the turning operation is performed, the tip tool is pressed against the workpiece and the impact driving mechanism is moved, so that the driven clutch member is moved from the torque transmission cutoff position to the torque transmission position. Configured to
In a state where the driven clutch member is located at the torque transmission position, torque is transmitted from the driving clutch member to the driven clutch member via a frictional force generated between the driven clutch member and the driving clutch member. The impact tool, wherein the clutch mechanism is configured such that the torque of the output shaft is transmitted to the tip tool and the tip tool is driven in the long axis direction. The impact tool according to claim 1,
The striking drive mechanism includes a striking element accommodated in the cylinder,
The striker is linearly driven through pressure fluctuations in the air chamber between the cylinder and the striker generated by the reciprocating movement of the cylinder, and the tip tool is driven to strike in the major axis direction by the linear drive of the striker. A striking tool characterized in that it is configured to be made. The impact tool according to claim 1 or 2,
A rotational drive mechanism for rotationally driving the tip tool around the major axis direction;
Rotation drive mode in which the tip tool is rotated in the major axis direction without being linearly driven to perform drilling work on the workpiece, and the tip tool is linearly driven in the major axis direction. And a driving mode switching unit that switches the driving mode between the hammering driving mode and the hammering driving mode in which the hammer drill operation is performed on the workpiece by rotating around the long axis, and the hammering driving mode.
The driven clutch member is allowed to move from the torque transmission blocking position to the torque transmission position in a state where the driving mode switching unit is switched to the hammering driving mode or the hammering rotation driving mode. The driven tool is configured to be moved from the torque transmission cutoff position to the torque transmission position by pressing the tip tool and moving the impact driving mechanism.
In the state switched to the rotational drive mode, the driven clutch member is configured to be maintained at the torque transmission cutoff position,
In a state where the driven clutch member is located at the torque transmission position, torque is transmitted from the driving clutch member to the driven clutch member via a frictional force generated between the driven clutch member and the driving clutch member. The impact tool according to claim 1, wherein the clutch mechanism is configured to transmit torque of the output shaft to the tip tool. It is an impact tool given in any 1 paragraph of Claims 1-3,
The drive clutch member is rotationally driven by the motor and has a rotation axis parallel to the major axis direction of the tip tool.
The driven clutch member is disposed coaxially with the rotation axis of the drive clutch member, and the torque transmission cutoff position is closer to the tip region than the torque transmission cutoff position with respect to the longitudinal direction of the tip tool. It is configured to be movable between the torque transmission position separated from the tip region,
The clutch mechanism is disposed between the drive clutch member and the driven clutch member, and a transmission position for transmitting torque from the drive clutch member to the driven clutch member, and the transmission position with respect to the rotation axis of the drive clutch member. And a transmission member that is movable between a non-transmission position where torque transmission from the drive clutch member to the driven clutch member is impossible,
The driven clutch member is configured to move from the torque transmission cutoff position to the torque transmission position by pressing the tip tool against the workpiece and moving the impact driving mechanism.
When the driven clutch member is positioned at the torque transmission cutoff position, the transmission member is disposed at the non-transmittable position, and transmission of torque from the drive clutch member to the driven clutch member is blocked.
When the driven clutch member is located at the torque transmission position, the transmission member is disposed at the transmission position, and is generated between the transmission member and the driven clutch member and between the transmission member and the drive clutch member. A striking tool configured to transmit torque from the driving clutch member to the driven clutch member via a frictional force. The impact tool according to any one of claims 1 to 3,
The drive clutch member is rotationally driven by the motor and has a rotation axis parallel to the major axis direction of the tip tool.
The driven clutch member is disposed coaxially with the rotation axis of the drive clutch member, and the torque transmission cutoff position is closer to the tip region than the torque transmission cutoff position with respect to the longitudinal direction of the tip tool. It is configured to be movable between the torque transmission position separated from the tip region,
The drive clutch member has a circular cross section perpendicular to the rotation axis, and includes a drive taper surface region provided so as to be inclined with respect to the rotation axis.
The driven clutch member has a circular cross section perpendicular to the rotation axis, and is provided so as to be inclined with respect to the rotation axis, and includes a driven taper surface region capable of contacting the drive taper surface region,
The driven clutch member is configured to move from the torque transmission cutoff position to the torque transmission position by pressing the tip tool against the workpiece and moving the impact driving mechanism.
When the driven clutch member is located at the torque transmission cut-off position, the driven taper surface region and the drive taper surface region are spaced apart from each other, and transmission of torque from the drive clutch member to the driven clutch member is cut off. ,
When the driven clutch member is located at the torque transmission position, the driven taper surface region and the drive taper surface region come into contact with each other via the frictional force generated between the driven taper surface region and the drive taper surface region. A striking tool configured to transmit torque from a driving clutch member to the driven clutch member. It is an impact tool given in any 1 paragraph of Claims 1-3,
The drive clutch member is rotationally driven by the motor and has a rotation axis parallel to the major axis direction of the tip tool.
The driven clutch member is disposed coaxially with the rotation axis of the drive clutch member, and the torque transmission cutoff position is closer to the tip region than the torque transmission cutoff position with respect to the longitudinal direction of the tip tool. It is configured to be movable between the torque transmission position separated from the tip region,
The clutch mechanism is disposed between the drive clutch member and the driven clutch member, and is disposed between the drive friction plate engaged with the drive clutch member, the drive clutch member and the driven clutch member, and the driven A driven friction plate that engages with the clutch member;
The drive friction plate and the driven friction plate are arranged side by side in the rotational axis direction of the drive clutch member,
The driven clutch member is configured to move from the torque transmission cutoff position to the torque transmission position by pressing the tip tool against the workpiece and moving the impact driving mechanism.
When the driven clutch member is located at the torque transmission cutoff position, the driving friction plate and the driven friction plate are spaced apart from each other, and transmission of torque from the driving clutch member to the driven clutch member is interrupted,
When the driven clutch member is located at the torque transmission position, the driven friction plate and the driven friction plate come into contact with each other, and the driven clutch member is driven from the driven clutch member by a friction force generated between the driving friction plate and the driven friction plate. A striking tool configured to transmit torque to a clutch member.

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