WO2013118840A1

WO2013118840A1 - Impact tool

Info

Publication number: WO2013118840A1
Application number: PCT/JP2013/052940
Authority: WO
Inventors: 陽之介青木; 正夫三輪
Original assignee: 株式会社マキタ
Priority date: 2012-02-09
Filing date: 2013-02-07
Publication date: 2013-08-15
Also published as: JP2013163234A

Abstract

[Problem] To provide an impact tool which is effectively reduced in weight. [Solution] An impact tool has: a motor (110) which is provided with a rotor (112), a stator (111), and an output shaft (113) which rotates together with the rotor (112); a crank mechanism (120) which converts the rotational motion of the motor (110) into rectilinear motion; and a tool drive mechanism (140) which is driven by the crank mechanism (120) and which drives a tool bit (119) in a rectilinear manner. The crank mechanism (120) has: a crankshaft (125) which is formed as a separate body from the output shaft (113) of the motor (110); and motion conversion members (127, 129) which convert the rotational motion of the crankshaft (125) into rectilinear motion and drives the tool drive mechanism (140). The motor (110) is configured as an outer rotor motor. The output shaft (113) and the crankshaft (125) are arranged coaxially with each other and are connected to each other.

Description

Impact tool

The present invention relates to an impact tool that performs a predetermined machining operation on a workpiece by driving a tool bit linearly using a crank mechanism.

Japanese Patent Application Laid-Open No. 2008-279987 discloses a crank-type electric hammer that drives a tool bit linearly using a crank mechanism. The crank mechanism of the electric hammer is configured to be driven by an electric motor.

In the electric hammer, an inner rotor type motor in which a rotor is arranged inside the stator is adopted as an electric motor. The speed of the motor is reduced by a reduction mechanism using gears and transmitted to the crank mechanism, thereby generating a predetermined striking force.

However, the above-described electric hammer is provided with a speed reduction mechanism between the output shaft of the electric motor and the crankshaft, so that the weight increases, and there is still room for improvement in this respect.

The present invention has been made in view of the above, and an object thereof is to provide a striking tool effective in reducing the weight.

In order to solve the above problems, according to a preferred embodiment of the present invention, a striking tool for performing a predetermined processing operation on a workpiece by a striking operation in the major axis direction of a tool bit is configured. The impact tool includes a rotor, a stator, and a motor having an output shaft that rotates integrally with the rotor, a crank mechanism that converts the rotational motion of the motor into a linear motion, and a crank mechanism that is driven to linearize the tool bit. And a tool driving mechanism for driving. The crank mechanism includes a crankshaft formed separately from the output shaft of the motor, and a motion conversion member that converts the rotational motion of the crankshaft into a linear motion and drives the tool drive mechanism. The motor is configured as an outer rotor type motor in which a rotor is disposed outside a stator, and an output shaft and a crankshaft are disposed coaxially and connected to each other.

According to the present invention, by using the outer rotor type motor, it becomes possible to generate a large rotor inertia moment with a large outer diameter of the rotating portion, and generate a large torque compared to an inner rotor type motor having the same external dimensions. be able to. For this reason, by arranging the motor output shaft and the crankshaft coaxially and connecting them, it is possible to omit the speed reduction mechanism required for the inner rotor type motor. As a result, the impact tool is reduced in weight and operability is improved. Further, by using the outer rotor type motor, the number of revolutions for obtaining a predetermined motor output can be lowered, so that the vibration of the impact tool caused by the motor vibration can be reduced. Further, according to the present invention, the motor output shaft and the crankshaft are formed separately, so that the motor side and the crank mechanism can be separated. Thereby, the repair at the time of failure of an impact tool becomes easy.

According to the further form of the impact tool which concerns on this invention, the output shaft and the crankshaft are each supported by the bearing in the axial direction several places.
According to this aspect, the output shaft and the crankshaft can be stably rotated by supporting the output shaft and the crankshaft at a plurality of locations.

According to the further form of the impact tool which concerns on this invention, the several bearing which supports an output shaft is supported by the single bearing support member.
According to this aspect, by supporting a plurality of bearings with a single bearing support member, it is possible to improve the positional accuracy of the output shaft as compared to a configuration in which the plurality of bearing support members are supported. Furthermore, by reducing the number of members, the structure can be simplified and assembly can be facilitated.
Further, the stator of the motor is preferably supported by the bearing support member.

According to the further form of the impact tool which concerns on this invention, the output shaft and the crankshaft are connected via the interposition member. The torque is transmitted from the output shaft in the order of the interposed member and the crankshaft.
According to this embodiment, the interposed member can function as a torque transmission member.

According to the further form of the impact tool which concerns on this invention, one axis | shaft of an output shaft and a crankshaft is inserted inside the other axis | shaft. And the interposition member is arrange | positioned between the outer side of one axis | shaft, and the inner side of the other axis | shaft.
According to this aspect, the interposition member has a function of dealing with a shaft position deviation that allows a deviation of the shaft position between the output shaft and the crankshaft.

According to the further form of the impact tool which concerns on this invention, it has a biasing member which biases an interposition member to an axial direction. A first recess along the axial direction is formed on the outer surface of one shaft, and a second recess along the axial direction is formed on the inner surface of the other shaft. And the interposition member is comprised so that transmission of torque is possible by engaging with a 1st recessed part and a 2nd recessed part. Note that the “biasing member” in this embodiment typically corresponds to a compression coil spring.
According to this aspect, with respect to the assembly of the output shaft and the crankshaft, when one shaft is inserted inside the other shaft, the interposition member engages with any one of the first recess and the second recess. Even if not, by rotating the output shaft and the crankshaft relative to each other while one shaft is inserted inside the other shaft, the interposition member is engaged with one of the recesses by the biasing force of the biasing member. Match. For this reason, the output shaft and the crankshaft can be easily assembled.

According to the present invention, a striking tool effective in reducing the weight is provided.

It is a sectional view showing the whole electric hammer composition concerning a 1st embodiment. It is sectional drawing which expands and shows the connection structure of a motor shaft and a crankshaft. FIG. 2 is a sectional view taken along line AA in FIG. 1. It is sectional drawing which shows the whole structure of the hammer drill which concerns on 2nd Embodiment. It is sectional drawing which expands and shows the structure of the drive mechanism part of a hammer drill. FIG. 5 is a sectional view taken along line BB in FIG. 4.

(First embodiment)
Hereinafter, the first embodiment will be described in detail with reference to FIGS. In the first embodiment, description will be made using an electric hammer as an example of a striking tool. As shown in FIG. 1, the electric hammer 100 is mainly configured by a main body portion 101 as a tool main body that forms an outline of the electric hammer 100. A hammer bit 119 is detachably attached to the distal end region of the main body 101 via a cylindrical tool holder 159. The hammer bit 119 is attached to the tool holder 159 so as to be relatively movable in the major axis direction, and is attached so as to rotate integrally with the tool holder 159 in the circumferential direction. A hand grip 107 gripped by the operator is connected to the end of the main body 101 opposite to the tip region. The hand grip 107 extends in the vertical direction in FIG. 1 intersecting the major axis direction of the hammer bit 119, and each end in the extending direction is connected to the main body 101. The hand grip 107 is provided as a substantially D-type main handle in a side view.

The hammer bit 119 is an implementation configuration example corresponding to the “tool bit” in the present invention. In the present embodiment, for convenience, the hammer bit 119 side of the electric hammer 100 in the longitudinal direction of the hammer bit 119 is defined as “front side” or “front side”, and the hand grip 107 side of the electric hammer 100 is defined as It is defined as “rear side” or “rear side”. 1 is defined as “upper side” or “upper side”, and the lower side is defined as “lower side” or “lower side”.

The main body 101 is composed mainly of an outer housing 103 that houses the electric motor 110, the motion conversion mechanism 120, and the striking element 140. The electric motor 110 is an implementation configuration example corresponding to the “motor” in the present invention. The rotation output of the electric motor 110 is appropriately converted into a linear motion by the motion conversion mechanism 120 and then transmitted to the striking element 140, and the major axis direction of the hammer bit 119 (the left-right direction in FIG. 1) via the striking element 140. An impact force is generated. The electric motor 110 is driven by a pulling operation of a trigger 107 a disposed on the hand grip 107.

As shown in FIG. 2, the electric motor 110 is configured as an outer rotor type motor in which a stator 111 is disposed on the inner side and a rotor 112 that rotates integrally with the motor shaft 113 is disposed on the outer side. The electric motor 110 is arranged so that the major axis direction of the motor shaft 113 is orthogonal to the major axis direction of the hammer bit 119. The stator 111 is mainly composed of a coil holding member 111b for holding the drive coil 111a and a cylindrical mounting member 111c for supporting the coil holding member 111b. The cylindrical mounting member 111 c is fixedly supported by an inner housing 104 fixed to the outer housing 103. The inner housing 104 includes an upper housing portion 104a and a lower housing portion 104b. The lower housing portion 104b is formed in a substantially cylindrical shape extending in the vertical direction. A cylindrical mounting member 111c of the stator 111 is fitted and fixed to the outside of the cylindrical portion of the lower housing portion 104b.

The rotor 112 is formed as a substantially cup-shaped member that is supported on the motor shaft 113 so as to be integrally rotatable. A magnet 115 facing the outer periphery of the stator 111 is attached to the inner peripheral surface (side wall inner surface) of the rotor 112. Further, one end portion (lower end portion) of the motor shaft 113 in the axial direction is press-fitted into the central portion of the rotor 112, and the rotor 112 and the motor shaft 113 are coupled. The motor shaft 113 is an implementation configuration example corresponding to the “output shaft” in the present invention. The motor shaft 113 extends upward through the inner space of the lower housing portion 104b in a loose fit. The motor shaft 113 has an upper side supported by a ball bearing 116 inside a lower housing portion 104b and a lower side supported by a needle bearing 117 so as to be rotatable. That is, the motor shaft 113 is supported by the

bearings

116 and 117 at a plurality of locations in the axial direction. The

bearings

116 and 117 are implementation configuration examples corresponding to the “bearings” in the present invention. Moreover, the lower housing part 104b which supports the

bearings

116 and 117 is the implementation structural example corresponding to the "bearing support member" in this invention.

As shown in FIG. 2, the motion conversion mechanism 120 connects the crankshaft 125, the eccentric shaft 127 provided at a position shifted from the rotation center of the crankshaft 125, the piston 131, and the piston 131 and the eccentric shaft 127. The crank mechanism is composed of a connecting rod 129 and the like. The crankshaft 125 is formed separately from the motor shaft 113 of the electric motor 110. The crankshaft 125 is disposed coaxially with the motor shaft 113 and is coupled to rotate integrally with the motor shaft 113. The crankshaft 125 is disposed above the motor shaft 113, and is supported rotatably by ball bearings 126 at two upper and lower positions in the axial direction. The ball bearing 126 is supported by the upper housing 104 a of the inner housing 104. The rotational motion of the crankshaft 125 is converted into a linear motion via the eccentric shaft 127 and the connecting rod 129 and transmitted to the piston 131. The piston 131 is configured to slide linearly in the long axis direction of the hammer bit 119 in the cylinder 141 and drive the striking element 140. The eccentric shaft 127 and the connecting rod 129 are an implementation configuration example corresponding to the “motion converting member” in the present invention.

As shown in FIG. 2, the crankshaft 125 has a through hole 125a having a circular cross section passing through the center. The upper end portion of the motor shaft 113 is inserted into the through hole 125a from below so as to be loosely fitted. Two concave grooves 125b are formed on the inner surface of the through hole 125a so as to extend in the axial direction with a predetermined length downward from the upper end surface of the crankshaft 125. As shown in FIG. 3, the groove 125 b is a groove having a substantially semicircular cross section provided symmetrically with respect to the central axis of the crankshaft 125. In each of the concave grooves 125b, a substantially cylindrical engaging member 133 is disposed so that approximately half of the radial direction protrudes toward the through hole 125a. The engaging member 133 is allowed to move in the axial direction of the crankshaft 125 in the concave groove 125b. In order to prevent the engaging member 133 from falling off the concave groove 125b toward the through hole 125a, the cross section of the concave groove 125b is formed to have an arc larger than a semicircle. This concave groove 125b is an implementation configuration example corresponding to the “first concave portion” in the present invention.

Further, as shown in FIG. 2, the engaging member 133 is always urged downward by the compression coil spring 135 disposed on the upper side of the through hole 125a. Therefore, in the state before the assembly in which the motor shaft 113 is inserted into the crankshaft 125, the engaging member 133 is in contact with the lower end portion of the concave groove 125b. The upper end of the compression coil spring 135 is supported by the crankshaft 125 via a retaining ring 137. The compression coil spring 135 is an implementation configuration example corresponding to the “biasing member” in the present invention.

On the other hand, on the upper outer surface of the motor shaft 113, as shown in FIGS. 2 and 3, two engaging recesses 113a corresponding to the recess grooves 125b of the crankshaft 125 are formed. The engaging recess 113 a is arranged symmetrically with respect to the central axis of the motor shaft 113. The engaging recess 113a has a substantially semicircular cross section. The engaging member 133 is disposed inside the recessed groove 125 b and the engaging recessed portion 113 a, whereby the motor shaft 113 and the crankshaft 125 are connected via the engaging member 133. As a result, torque is transmitted in the order of the motor shaft 113, the engaging member 133, and the crankshaft 125. This engaging member 133 is an implementation structural example corresponding to the "interposition member" in this invention. The engaging recess 113a is an implementation configuration example corresponding to the “second recess” in the present invention.

As shown in FIG. 1, the upper housing portion 104 a of the inner housing 104 extends in the front-rear direction for accommodating the cylinder 141 and the tool holder 159 and in the vertical direction for accommodating the crankshaft 125. A substantially cylindrical rear portion. As shown in FIG. 2, the lower housing portion 104b is disposed below the rear portion of the upper housing portion 104a, and the upper housing portion 104a and the lower housing portion 104b are joined by a joining means (not shown) such as a screw. Be joined. The electric motor 110 is preferably prepared as a motor assembly in which constituent members such as a stator 111, a rotor 112, and a motor shaft 113 are previously assembled to the lower housing portion 104b. The motor assembly is assembled by joining the lower housing portion 104b to the upper housing portion 104a so that the upper end portion of the motor shaft 113 is inserted into the through hole 125a of the crankshaft 125.

When the motor shaft 113 is inserted into the crankshaft 125 in the assembly of the motor assembly, if the positions of the concave groove 125b and the engaging concave portion 113a are shifted in the circumferential direction, the engaging member 133 is attached to the motor shaft 113. It is pushed by the upper end surface and moves upward in the concave groove 125b to be held. When the motor shaft 113 is rotated in the circumferential direction relative to the crankshaft 125 in this state, the circumferential positions of the concave groove 125b and the engaging concave portion 113a coincide with each other, and the engaging member 133 is attached to the compression coil spring 135. The force is inserted into the engagement recess 113a and engaged with the engagement recess 113a. For this reason, the motor shaft 113 can be easily assembled to the crankshaft 125.

As shown in FIG. 1, the striking element 140 is mainly composed of a striker 143, an impact bolt 145, and the like. The striker 143 is configured as a striker that is slidably disposed with respect to the bore inner wall of the cylinder 141. The impact bolt 145 is slidably disposed in the tool holder 159 and is configured as an intermediate element that transmits the kinetic energy (striking force) of the striker 143 to the hammer bit 119. The striker 143 is driven by an air spring in the air chamber 141a of the cylinder 141 accompanying the sliding movement of the piston 131, hits an impact bolt 145 disposed in the tool holder 159, and the hammer bit 119 is passed through the impact bolt 145. Generate a striking force. This striking element 140 is an implementation configuration example corresponding to the “tool driving mechanism” in the present invention.

In the electric hammer 100 configured as described above, when the electric motor 110 is driven by the pulling operation of the trigger 107a, the hammer bit 119 is driven by the movement through the striking element 140 from the motion conversion mechanism 120 configured by a crank mechanism. A striking force in the direction of the major axis is generated. As a result, the hammer bit 119 performs a hammering operation in the major axis direction, and performs a drilling operation on a workpiece such as concrete.

According to the first embodiment, by adopting the outer rotor type motor as the electric motor 110, the outer diameter of the rotor 112 can be increased, and a large rotor inertia moment can be generated. For this reason, compared with an inner rotor type motor, a big torque can be generated. In the case of an inner rotor type motor, it is necessary to obtain a necessary torque by providing a speed reduction mechanism between the motor shaft and the intermediate shaft in order to generate a predetermined striking force. This may increase the weight or increase the size of the aircraft. However, according to the first embodiment, the use of the outer rotor type motor eliminates the need for a speed reduction mechanism. Thereby, the electric hammer 100 can be reduced in weight and size. As a result, the operability of the electric hammer 100 when performing a machining operation can be improved. Moreover, since the rotation speed of the electric motor 110 for obtaining a predetermined output can be reduced, the vibration of the electric hammer 100 due to the vibration of the electric motor 110 can be reduced. Further, the countermeasure for resonance due to vibration is not required, and the durability of the

bearings

116 and 117 is improved.

Further, according to the first embodiment, when the motor shaft 113 is assembled to the crankshaft 125, the motor shaft 113 is inserted into the through hole 125a, and the motor shaft 113 and the crankshaft 125 are relatively rotated after the insertion. Thus, the engagement member 133 can be automatically engaged with the engagement recess 113a by the urging force of the compression coil spring 135. For this reason, the motor shaft 113 and the crankshaft 125 can be easily assembled. Moreover, since the motor shaft 113 and the crankshaft 125 are formed separately, the electric motor 110 side and the crank mechanism side can be separated. Therefore, repair at the time of failure of the electric hammer 100 is facilitated.

Further, according to the first embodiment, the engaging shaft 133 fixed in the circumferential direction of the crankshaft 125 is engaged with the engaging recess 113a of the motor shaft 113, whereby the motor shaft 113 and the crankshaft 125 are connected. In order to make the connection, a predetermined gap can be set in the radial direction between the engaging member 133 and the engaging recess 113a. That is, even if there is a deviation between the center positions of the motor shaft 113 and the crankshaft 125, the deviation can be allowed by the gap. In other words, the engagement member 133 has a function as a torque transmission member and a position shift corresponding member function that allows a shift in the center position between the motor shaft 113 and the crankshaft 125.

According to the first embodiment, since the motor shaft 113 and the crankshaft 125 are supported by the

bearings

116, 117, and 126 at a plurality of locations in the axial direction, the motor shaft 113 and the crankshaft 125 are stable. It is rotated. The

bearings

116 and 117 for supporting the motor shaft 113 are supported by the lower housing portion 104b that is a single member. For this reason, compared with the case where the

bearings

116 and 117 are supported by separate bearing support members, the number of members can be reduced. As a result, the structure can be simplified and assembly can be easily performed.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. The second embodiment is an example in which the hammer is changed from an electric hammer as a hammering tool. FIG. 4 shows the overall configuration of the hammer drill 200. The hammer drill 200 is configured to rotate around the long axis direction in addition to the hammer bit 119 striking operation in the long axis direction. That is, in addition to the motion conversion mechanism 120 and the striking element 140, a power transmission mechanism 150 for transmitting the rotational output of the electric motor 110 to the hammer bit 119 is further provided. The components other than the power transmission mechanism 150 are configured similarly to the electric hammer 100 of the first embodiment. Therefore, components other than the power transmission mechanism 150 are denoted by the same reference numerals as those used in the first embodiment, and description thereof is omitted.

As shown in FIG. 5, the power transmission mechanism 150 according to the second embodiment includes a first intermediate shaft 151 and a second intermediate shaft 152 that are arranged in parallel to the motor shaft 113. A first intermediate gear 154 and a second intermediate gear 155 having a smaller diameter than the first intermediate gear 154 are fixedly attached to the first intermediate shaft 151. A third intermediate gear 156 that is always meshed with and engaged with the second intermediate gear 155 is fixedly attached to the second intermediate shaft 152. The first intermediate gear 154 always meshes and engages with a drive gear 153 driven by the electric motor 110. Accordingly, the torque of the electric motor 110 is transmitted from the drive gear 153 through the first to third

intermediate gears

154, 155 and 156 at a predetermined reduction ratio and transmitted to the second intermediate shaft 152.

The torque transmitted to the second intermediate shaft 152 is transmitted from the small bevel gear 157 formed integrally with the second intermediate shaft 152 to the large bevel gear 158 engaged with and engaged with the small bevel gear 157. The large bevel gear 158 is coupled to the tool holder 159 and configured to transmit torque to the hammer bit 119.

In the second embodiment, as shown in FIG. 5, the lower housing portion 104 b of the inner housing 104 supports the motor support region that supports the electric motor 110, the first intermediate shaft 151, and the second intermediate shaft 152. An intermediate shaft support region is provided which is supported via 151a and 152a.

As shown in FIGS. 5 and 6, in the hammer drill 200, the motor shaft 113 is disposed coaxially with the crankshaft 125 of the motion conversion mechanism 120, and the motor shaft 113 and the crankshaft 125 are interposed via the engaging member 133. Are connected. The connection structure between the motor shaft 113 and the crankshaft 125 is the same as in the first embodiment. Further, in the second embodiment, a drive gear 153 is provided on the motor shaft 113, and the torque of the motor shaft 113 is transmitted to the hammer bit 119.

According to the second embodiment, the hammer drill 200 can be reduced in weight and size. Thus, the same operational effects as those of the electric hammer 100 of the first embodiment can be obtained, for example, the operability of the electric hammer 100 when performing a machining operation can be improved.

In the second embodiment, the drive gear 153 is attached to the motor shaft 113, but the drive gear 153 may be attached to the crankshaft 125.

In the first and second embodiments, the engaging member 133 is a columnar member, but can be changed to a steel ball. In the first and second embodiments, the engaging member 133 is disposed as an interposed member between the outer side of the motor shaft 113 and the inner side of the crankshaft 125, but is not limited thereto. For example, the motor shaft 113 and the crankshaft 125 may be connected using a coupling as an interposed member. A key may be used as the interposition member.

In addition, with regard to the connection structure between the motor shaft 113 and the crankshaft 125, a spline hole is set on one shaft and a spline shaft is set on the other shaft without using an intervening member. You may connect. Moreover, it is also possible to change to a connection structure by press-fitting or a connection structure using a two-sided width.

In view of the gist of the above invention, the impact tool according to the present invention can be configured in the following manner.
(Aspect)
The impact tool according to claim 4,
The bearing support member is provided as a cylindrical member,
The output shaft is supported by the bearing inside the bearing support member,
The impact tool according to claim 1, wherein the stator is supported outside the bearing support member.

100 Electric hammer (blow tool)
101 Body 103 Outer housing 104 Inner housing 104a Upper housing part 104b Lower housing part (bearing support member)
107 hand grip 107a trigger 110 electric motor (motor)
111 Stator 111a Drive coil 111b Coil holding member 111c Cylindrical mounting member 112 Rotor 113 Motor shaft (output shaft)
113a Engaging recess (second recess)
115 Magnet 116 Ball Bearing 117 Needle Bearing 119 Hammer Bit (Tool Bit)
120 Motion conversion mechanism (crank mechanism)
125 Crankshaft 125a Through hole (hole)
125b Groove (first recess)
126 Ball bearing 127 Eccentric shaft (motion conversion member)
129 Connecting rod (motion conversion member)
131 piston 133 engaging member (intervening member)
135 Compression coil spring (biasing member)
137 Retaining Ring 140 Impact Element (Tool Drive Mechanism)
141 cylinder 141a air chamber 143 striker 145 impact bolt 150 power transmission mechanism 151 first intermediate shaft 151a bearing 152 second intermediate shaft 152a bearing 153 drive gear 154 first intermediate gear 155 second intermediate gear 156 third intermediate gear 157 small bevel gear 158 Large bevel gear 159 Tool holder

Claims

A striking tool that performs a predetermined processing operation on a workpiece by a striking motion in the long axis direction of a tool bit,
A rotor, a stator, and a motor having an output shaft that rotates integrally with the rotor;
A crank mechanism for converting the rotational motion of the motor into linear motion;
A tool drive mechanism that is driven by the crank mechanism and drives the tool bit linearly;
The crank mechanism has a crankshaft formed separately from the output shaft of the motor, and a motion conversion member that converts the rotational motion of the crankshaft into a linear motion to drive the tool drive mechanism,
The motor is configured as an outer rotor type motor in which the rotor is disposed outside the stator,
The impact tool, wherein the output shaft and the crankshaft are coaxially arranged and connected to each other.
The impact tool according to claim 1,
Each of the output shaft and the crankshaft is supported by a bearing at a plurality of locations in the axial direction.
The impact tool according to claim 2,
A plurality of bearings that support the output shaft are supported by a single bearing support member.
The impact tool according to claim 3,
The hitting tool, wherein the stator is supported by the bearing support member.
The striking tool according to any one of claims 1 to 4,
The output shaft and the crankshaft are connected via an interposed member,
A striking tool configured to transmit torque in the order of the intermediate member and the crankshaft from the output shaft.
The impact tool according to claim 5,
One of the output shaft and the crankshaft is inserted inside the other shaft,
The impact tool, wherein the interposition member is arranged between the outer side of the one shaft and the inner side of the other shaft.
The impact tool according to claim 6,
A biasing member for biasing the interposition member in the axial direction;
A first recess along the axial direction is formed on the outer surface of the one shaft,
A second recess along the axial direction is formed on the inner surface of the other shaft,
The impact tool is characterized in that the torque can be transmitted by engaging the interposition member with the first recess and the second recess.