JP2021065962A - Hammering tool - Google Patents

Abstract

To provide a hammering tool, which is improved in a structure for guiding movements of at least a portion of a driving mechanism with respect to a housing.SOLUTION: A hammer drill 101 comprises a spindle 31, a motor, a driving mechanism 5, a main body housing 10, a movable support body 18, a first guide shaft 191, and a second guide shaft 192. The movable support body 18 can move the spindle 31 and at least a portion of the driving mechanism 5 integrally in an axial direction of a driving axis A1 with respect to the main body housing 10, while being energized by a first energizing spring 194 and a second energizing spring 195. The first guide shaft 191 and the second guide shaft 192 are inserted respectively into support holes 190 of the movable support body 18, and slidably support the movable support body 18. A size of a gap between the first guide shaft 191 and a surface defining the support holes 190 is different from a size of a gap between the second guide shaft 192 and the surface defining the support holes 190.SELECTED DRAWING: Figure 15

Description

The present invention relates to a striking tool configured to drive a tip tool linearly.

A striking tool that drives a tip tool linearly along a drive shaft to perform machining work on a work piece generates relatively large vibration mainly in the direction of the drive shaft. Therefore, a technique for suppressing vibration transmission to a handle or a housing gripped by a user is known. For example, in the hammer drill disclosed in Patent Document 1, the striking mechanism portion housed in the housing is held by a holding member provided separately from the housing, and the housing is in a state where the urging force of the urging member acts. It is configured to move relative to. Then, the relative movement of the striking mechanism portion is guided in the long axis direction of the tip tool by a plurality of guide shafts fixed to the housing.

Japanese Unexamined Patent Publication No. 2016-000447

In the hammer drill of Patent Document 1, each of the plurality of guide shafts is inserted into a guide penetrating portion provided corresponding to the holding member. In such a configuration, it may be difficult to assemble due to an error in the guide shaft and the penetrating portion.

In view of such circumstances, it is an object of the present invention to provide an improvement in the structure for guiding the movement of the drive mechanism with respect to at least a part of the housing in the striking tool.

According to one aspect of the present invention, a striking tool including a final output shaft, a motor, a drive mechanism, a housing, a movable support, a first guide shaft, and a second guide shaft is provided.

The final output shaft is configured to hold the tip tool removable. The final output shaft defines the drive shaft of the tip tool. The motor has a motor shaft. The drive mechanism is configured to be capable of performing at least a hammer operation that linearly drives the tip tool along the drive shaft by the power of the motor. The housing houses the motor and drive mechanism. The movable support integrally moves with respect to the housing in the axial direction of the drive shaft while supporting at least a part of the final output shaft and the drive mechanism in the housing and being urged by at least one elastic member. It is configured to be possible. The first guide shaft is supported by the housing and extends parallel to the drive shaft in the housing. The second guide shaft is supported by the housing and extends parallel to the drive shaft in the housing.

Further, the movable support has a first hole and a second hole. The first hole and the second hole each penetrate the movable support in the axial direction. The first guide shaft and the second guide shaft are inserted into the first hole and the second hole, respectively, and support the movable support so as to be slidable in the axial direction. The size of the gap between the first guide shaft and the surface defining the first hole is different from the size of the gap between the second guide shaft and the surface defining the second hole. In other words, the size of the clearance with respect to the first guide shaft is different from the size of the clearance with respect to the second guide shaft.

In the striking tool of this embodiment, at least a part of the final output shaft and the drive mechanism is supported by the movable support and urged by at least one elastic member, and is integrated with the housing in the axial direction of the drive shaft. It is configured to be movable. As a result, the vibration generated in the drive mechanism is suppressed from being transmitted to the housing.

Further, the striking tool of this embodiment includes a first guide shaft and a second guide shaft for guiding the relative movement of the movable support. Attempts to fit both the first guide shaft and the second guide shaft into the first and second holes, respectively, with as close a gap as possible, will result in assembly due to shaft and / or hole error. It can be difficult. On the other hand, according to the configuration of this aspect, it is possible to facilitate the assembly while maintaining the guide function of the movable support well by forming a smaller gap with high accuracy.

In this embodiment, the first guide shaft and the second guide shaft may be directly supported by the housing, or may be supported by another member (a member that can be regarded as a part of the housing) fixed to the housing. May be good.

In one aspect of the present invention, the first guide shaft and the second guide shaft may be shafts having different diameters from each other. In this case, the size of the gap corresponding to the first guide shaft and the size of the gap corresponding to the second guide shaft can be easily made different.

In one aspect of the present invention, the portion of the movable support that defines the first hole and the second hole, respectively, may be formed of a material different from the other portions. In this case, a material suitable for each of the movable support, the portion that supports at least a part of the final output shaft and the drive mechanism, and the portion that slidably supports the first guide shaft and the second guide shaft. Can be formed with.

In one aspect of the invention, the striking tool may further include a handle that is connected to the housing and extends along an axis that intersects the drive axis. The first guide shaft and the second guide shaft may be arranged on both sides of a plane including the drive shaft and the shaft of the steering wheel. In this case, the first guide shaft and the second guide shaft can guide the relative movement of the movable support in a well-balanced manner on both sides of the drive shaft and the shaft of the handle. Further, the drive shaft and the respective shafts of the first guide shaft and the second guide shaft may be on the same plane intersecting the above planes. In this case, the first guide shaft and the second guide shaft can guide the relative movement of the movable support in a more balanced manner.

In one aspect of the present invention, the drive mechanism may be further configured to be capable of performing a drill operation that rotationally drives the tip tool around a drive shaft by the power of a motor. The striking tool may further include a first intermediate shaft and a second intermediate shaft, each of which is supported axially immovably with respect to the housing and is configured to rotate as the motor shaft rotates. The first intermediate shaft is configured to perform only the transmission for performing the hammering motion among the hammering motion and the drilling motion, and the second intermediate shaft performs the drilling motion among the hammering motion and the drilling motion. May be configured to only communicate for. That is, each striking tool may include a first intermediate shaft and a second intermediate shaft specialized for power transmission for hammer operation and power transmission for drill operation.

In this case, it is possible to shorten each of the first intermediate shaft and the second intermediate shaft as compared with the one intermediate shaft shared for the power transmission for the hammer operation and the power transmission for the drill operation. Become. Therefore, it is possible to reduce the length of the entire striking tool in the drive axis direction. Further, the power transmission from the first intermediate shaft to the first drive mechanism and the power transmission from the second intermediate shaft to the second drive mechanism and eventually to the final output shaft can be optimized respectively.

Further, in this embodiment, the striking tool may further include a handle that is connected to the housing and projects from the housing along an axis that intersects the drive shaft. The first intermediate shaft and the second intermediate shaft may be arranged on the protruding end side of the handle with respect to the first guide shaft and the second guide shaft in the axial direction of the handle. In this case, a well-balanced arrangement of the first guide shaft and the second guide shaft and the first intermediate shaft and the second intermediate shaft is realized.

In one aspect of the invention, the striking tool may further include at least one cushioning member held in one of the housing and the movable support. The at least one elastic member may be at least one spring. On the other hand, at least one cushioning member is an elastic body other than at least one spring, and may be arranged so as to abut against the other of the housing and the movable support when the at least one spring is deformed by a predetermined amount. .. In this case, at least one cushioning member can prevent the housing from colliding with the movable support. In this embodiment, the "at least one cushioning member" may be directly held by the housing, or may be held by another member (a member that can be regarded as a part of the housing) fixed to the housing. ..

In one aspect of the present invention, the drive mechanism may be further configured to be capable of performing a drilling operation that rotationally drives the tip tool around a drive axis. The final output shaft may be rotatably arranged around the drive shaft. The drive mechanism may include a drive gear and a driven gear. The drive gear is arranged on an intermediate shaft supported by a housing and is configured to rotate about a rotation axis parallel to the drive axis by the power of a motor. The driven gear is provided on the final output shaft and meshes with the drive gear. On a plane orthogonal to the drive shaft, the angle formed by the straight line passing through the rotation shaft and the drive shaft of the drive gear and the line segment connecting the shaft of the first guide shaft and the drive shaft is the straight line and the second guide. It may be smaller than the angle formed by the line segment connecting the shaft shaft and the drive shaft. The gap with respect to the first guide shaft may be smaller than the gap with respect to the second guide shaft. In this case, it is possible to suppress the influence on the engagement between the drive gear and the driven gear when the movable support rotates with respect to the housing.

It is sectional drawing of a hammer drill. It is a partially enlarged view of a hammer drill. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. It is sectional drawing of the modification of the bearing support. It is sectional drawing in the VV line of FIG. FIG. 5 is a cross-sectional view taken along the line VI-VI of FIG. FIG. 5 is a cross-sectional view taken along the line VII-VII of FIG. FIG. 5 is a cross-sectional view taken along the line VIII-VIII of FIG. It is a partially enlarged view of FIG. It is a partially enlarged view of FIG. It is a figure corresponding to FIG. 8, and is explanatory drawing of the operation of a torque limiter. It is a partial bottom view of the hammer drill with the front housing removed, and shows the mode switching mechanism when the hammer drill mode is selected. It is a figure which shows the mode switching mechanism when a hammer mode is selected. It is a figure which shows the mode switching mechanism when a drill mode is selected. FIG. 5 is a cross-sectional view taken along the line XVIII-XVIII of FIG. It is sectional drawing in the XIX-XIX line of FIG. FIG. 5 is a cross-sectional view taken along the line XX-XX of FIG. It is explanatory drawing of the determination method of the reference guide shaft. It is explanatory drawing of assembly of a lock plate. It is explanatory drawing of assembly of a lock plate. It is explanatory drawing of assembly of a lock plate. It is a partially enlarged view of FIG. It is a figure corresponding to FIG. 22, and is explanatory drawing of the operation of the blank hit prevention mechanism. It is explanatory drawing of the modification of the shock absorbing ring. It is explanatory drawing of the modification of the shock absorbing ring. It is explanatory drawing of the modification of the shock absorbing ring. It is explanatory drawing of the modification of the shock absorbing ring.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the hammer drill 101 is illustrated as an example of a striking tool. The hammer drill 101 is a hand-held power tool used for machining work such as chipping work and drilling work, and is an operation of linearly driving the tip tool 91 along a predetermined drive shaft A1 (hereinafter referred to as a hammer operation). , And the operation of rotationally driving the tip tool 91 around the drive shaft A1 (hereinafter referred to as a drill operation) can be performed.

First, the schematic configuration of the hammer drill 101 will be briefly described with reference to FIG. As shown in FIG. 1, the outer shell of the hammer drill 101 is mainly formed by a main body housing 10 and a handle 17 connected to the main body housing 10.

The main body housing 10 is a hollow body, which is also called a tool main body or an outer housing, and houses a spindle 31, a motor 2, a drive mechanism 5, and the like. The spindle 31 is a long cylindrical member, and is provided with a tool holder 32 that removably holds the tip tool 91 at one end in the axial direction thereof. The long axis of the spindle 31 defines the drive axis A1 of the tip tool 91. The main body housing 10 extends along the drive shaft A1. The tool holder 32 is arranged in one end of the main body housing 10 in the extending direction of the drive shaft A1 (hereinafter, simply referred to as the drive shaft direction).

The handle 17 is a long hollow body gripped by the user. One end of the handle 17 in the axial direction is connected to the other end of the main body housing 10 in the drive axis direction (the end opposite to the side where the tool holder 32 is arranged). The handle 17 extends in a direction intersecting the drive shaft A1 (specifically, a direction substantially orthogonal to each other) so as to project from the other end of the main body housing 10. In the present embodiment, the main body housing 10 and the handle 17 are integrated by connecting a plurality of constituent members with screws or the like. A power cable 179 that can be connected to an external AC power source extends from the protruding end of the handle 17. The handle 17 has a trigger 171 that is pressed (pulled) by the user, and a switch 172 that is turned on in response to the pressing operation of the trigger 171.

In the hammer drill 101, when the switch 172 is turned on, the motor 2 is energized and the drive mechanism 5 is driven to perform a hammer operation and / or a drill operation.

Hereinafter, the detailed configuration of the hammer drill 101 will be described. In the following description, for convenience, the extending direction of the drive shaft A1 (the long axis direction of the main body housing 10) is defined as the front-rear direction of the hammer drill 101. In the front-rear direction, one end side on which the tool holder 32 is arranged is defined as the front side of the hammer drill 101, and the opposite side (the side to which the handle 17 is connected) is defined as the rear side. Further, the direction orthogonal to the drive shaft A1 and corresponding to the axial direction of the handle 17 is defined as the vertical direction of the hammer drill 101. In the vertical direction, the side where the handle 17 is connected to the main body housing 10 is defined as the upper side, and the protruding end side of the handle 17 is defined as the lower side. Further, the direction orthogonal to the front-rear direction and the up-down direction is defined as the left-right direction.

First, the configuration of the main body housing 10 will be described.

As shown in FIG. 1, the main body housing 10 has a cylindrical front end. This cylindrical portion is referred to as a barrel portion 131. The portion of the main body housing 10 other than the barrel portion 131 is formed in a substantially rectangular box shape. An auxiliary handle (not shown) can be attached to the barrel portion 131. Further, in addition to the handle 17, the user can auxiliary grip the barrel portion 131 to which the auxiliary handle is not mounted.

The internal space of the main body housing 10 is divided into two regions by a bearing support 15 arranged inside the main body housing 10. The bearing support 15 is arranged so as to intersect the drive shaft A1, is fitted into the inner circumference of the main body housing 10, and is held fixedly (immovably with respect to the main body housing 10) by the main body housing 10. ing. The region on the rear side of the bearing support 15 is mainly a region for accommodating the motor 2. The area on the front side of the bearing support 15 is mainly an area for accommodating the spindle 31 and the drive mechanism 5. Hereinafter, the portion of the main body housing 10 corresponding to the accommodation area of the motor 2 is referred to as a rear housing 11, and the portion corresponding to the accommodation area of the spindle 31 and the drive mechanism 5 (including the barrel portion 131) is referred to as a front housing 13. ..

The rear housing 11 and the front housing 13 are both made of resin (plastic). The rear housing 11 is formed by connecting a plurality of members. On the other hand, the front housing 13 is a single tubular member.

In this embodiment, the bearing support 15 is also made of resin (plastic). This is because the vibration-proof structure described later suppresses the vibration generated in the drive mechanism 5 from being transmitted to the main body housing 10 and the bearing support 15 fixedly attached to the main body housing 10. Therefore, the bearing support This is because the strength of 15 is not required to be as strong as that of metal. As a result, the weight of the hammer drill 101 can be reduced as compared with the case where the bearing support 15 is made of metal. Further, as shown in FIG. 2, the bearing support 15 is fitted into the rear end portion of the front housing 13 so that substantially the entire outer peripheral surface thereof is in contact with the inner peripheral surface of the front housing 13. ..

Although details will be described later, the bearing support 15 is a member that supports bearings of various shafts. Therefore, high accuracy is required for the outer peripheral dimensions that are fitted inside the main body housing 10. Therefore, when such a bearing support 15 is formed of a metal (for example, an aluminum alloy), it is preferable that processing is performed based on a single circle for dimensional accuracy. On the other hand, in the present embodiment, the degree of freedom in shape is increased by forming the bearing support 15 with resin. Specifically, as shown in FIG. 3, the cross-sectional shape of the bearing support 15 in the plane orthogonal to the drive shaft A1 is based on three circles instead of a single circle. Therefore, the outer circumference of the bearing support 15 (that is, the contact portion with the main body housing 10) is not on the circumference of a single circle, but on the circumference of each of the three circles. Part of is overlapping.

As shown in FIG. 2, an annular groove is formed on the outer peripheral surface of the bearing support 15 in contact with the inner peripheral surface of the main body housing 10. A rubber O-ring 151 is mounted in this groove. A lubricant is arranged in the front housing 13 in which the drive mechanism 5 is housed. The O-ring 151 functions as a sealing member that closes the gap between the main body housing 10 and the bearing support 15, and the lubricant passes through the gap between the main body housing 10 and the bearing support 15 and enters the rear housing 11. It is possible to prevent leakage to the housing. As a sealing member, instead of the O-ring 151 separate from the bearing support 15, for example, as shown in FIG. 4, an elastic body 152 made of a thermoplastic elastomer is integrated with the outer periphery of the resin bearing support 15. It may be molded. In this case, the bearing support 15 with the elastic body 152 can be easily assembled to the main body housing 10.

Further, as shown in FIGS. 3 and 5, the bearing support 15 has an internal space of the front housing 13 so as to adjust the pressure in the front housing 13 so as to match the pressure in the rear housing 11. An air vent hole 153 that communicates with the internal space of the rear housing 11 is provided. A filter 154 that prevents the lubricating oil from leaking into the rear housing 11 through the air bleeding hole 153 is fitted in the air bleeding hole 153 (see FIG. 17).

Hereinafter, the internal structure of the main body housing 10 will be described.

First, the motor 2 will be described. In the present embodiment, as the motor 2, an AC motor driven by electric power supplied from an external AC power source is adopted. As shown in FIG. 1, the motor 2 is fixed to the rear housing 11 by screws. The motor 2 includes a main body 20 including a stator and a rotor, and a motor shaft 25 configured to rotate integrally with the rotor. In the present embodiment, the rotation shaft A2 of the motor shaft 25 extends below the drive shaft A1 and parallel to the drive shaft A1. A virtual plane VP (hereinafter referred to as a reference plane VP) including the drive shaft A1 and the rotation shaft A2 (see FIGS. 3 and 5) extends in the vertical direction of the hammer drill 101.

The motor shaft 25 is rotatably supported around the rotation shaft A2 with respect to the main body housing 10 via two bearings 251 and 252. The front bearing 251 is held on the rear surface side of the bearing support 15, and the rear bearing 252 is held in the rear housing 11 (specifically, the inner housing that houses the motor 2 in the rear housing 11). ing. A fan 27 for cooling the motor 2 is fixed to a portion of the motor shaft 25 between the main body 20 and the front bearing 251. The front end of the motor shaft 25 penetrates the bearing support 15 and projects into the front housing 13. A pinion gear 255 is fixed to a portion protruding into the front housing 13.

Next, the power transmission path from the motor shaft 25 to the drive mechanism 5 will be described.

As shown in FIGS. 5 and 6, in the present embodiment, the hammer drill 101 includes two intermediate shafts (first intermediate shaft 41 and second intermediate shaft 42). The drive mechanism 5 is configured to perform a hammer operation by the power transmitted from the first intermediate shaft 41 and to perform a drill operation by the power transmitted from the second intermediate shaft 42. That is, the first intermediate shaft 41 is a shaft dedicated to power transmission for hammer operation. The second intermediate shaft 42 is a shaft dedicated to power transmission for drill operation.

Both the first intermediate shaft 41 and the second intermediate shaft 42 extend in the front housing 13 in parallel with the drive shaft A1 and the rotation shaft A2. The first intermediate shaft 41 is rotatably supported around the rotation shaft A3 with respect to the main body housing 10 via two bearings 411 and 412. The front bearing 411 is held in the front housing 13, and the rear bearing 412 is held in the front side of the bearing support 15. Similarly, the second intermediate shaft 42 is rotatably supported around the rotation shaft A4 with respect to the main body housing 10 via two bearings 421 and 422. The front bearing 421 is held in the front housing 13, and the rear bearing 422 is held in the front side of the bearing support 15. As described above, since the bearing 251 of the motor shaft 25 is also supported by the bearing support 15, it is possible to realize a highly accurate arrangement relationship between the motor shaft 25, the first intermediate shaft 41, and the second intermediate shaft 42. Can be done.

The first intermediate shaft 41 is arranged on the right side with respect to the reference plane VP. The second intermediate shaft 42 is arranged on the left side with respect to the reference plane VP. As a result, the weight balance in the left-right direction can be improved as compared with the case where the first intermediate shaft 41 and the second intermediate shaft 42 are arranged unevenly on the left side or the right side.

Further, on a plane orthogonal to the drive shaft A1, a line segment connecting the rotary shaft A2 of the motor shaft 25 and the rotary shaft A3 of the first intermediate shaft 41, and the rotary shaft A2 of the rotary shaft A2 and the rotary shaft A4 of the second intermediate shaft 42. The angle formed by the line segment connecting the two is an blunt angle. With such an arrangement, the first driven gear 414 and the second driven gear 424 mesh with the pinion gear 255 of the motor shaft 25 from substantially opposite directions. As a result, it is possible to prevent the pinion gear 255 from being subjected to a bending load in a specific direction. Further, as compared with the case where the first driven gear 414 and the second driven gear 424 are aligned in a straight line with the pinion gear 255 as the center, the first intermediate shaft is suppressed from being enlarged in the direction of the straight line as a whole. The necessary parts can be reasonably arranged on the 41 and the second intermediate shaft 42.

A first driven gear 414 is fixed to the rear end of the first intermediate shaft 41 adjacent to the front side of the bearing 412. The first driven gear 414 meshes with the pinion gear 255.

At the rear end of the second intermediate shaft 42, a gear member 423 having a second driven gear 424 is arranged adjacent to the front side of the bearing 422. The gear member 423 is formed in a cylindrical shape and is arranged on the outer peripheral side of the second intermediate shaft 42 (specifically, the drive side member 74 described later). A spline portion 425 is provided on the outer periphery of the cylindrical front end portion of the gear member 423. The spline portion 425 has a plurality of splines (external teeth) extending in the rotation axis A4 direction (front-rear direction). Although details will be described later, the rotation of the second driven gear 424 (gear member 423) is transmitted to the second intermediate shaft 42 via the second transmission member 72 and the torque limiter 73.

As described above, in the present embodiment, two power transmission paths branching from the motor shaft 25 are provided, and each of these paths is used as a power transmission path dedicated to hammer operation and a power transmission path dedicated to drill operation. Be done.

The spindle 31 will be described. The spindle 31 is the final output shaft of the hammer drill 101. As shown in FIG. 2, the spindle 31 is arranged in the front housing 13 along the drive shaft A1 and is rotatably supported around the drive shaft A1 with respect to the main body housing 10. The spindle 31 is configured as an elongated stepped cylindrical member.

The first half of the spindle 31 constitutes a tool holder 32 to which the tip tool 91 can be attached and detached. The tip tool 91 is inserted into the bit insertion hole 330 at the front end of the tool holder 32 so that its long axis coincides with the drive shaft A1, and is allowed to move in the axial direction with respect to the tool holder 32 so that the tip tool 91 can rotate around the axis. It is kept in a regulated state. The latter half of the spindle 31 constitutes a cylinder 33 that slidably holds the piston 65, which will be described later. In the present embodiment, the spindle 31 is a single member in which the tool holder 32 and the cylinder 33 are integrally formed, but may be formed by connecting a plurality of members. The spindle 31 is made of iron (or an alloy containing iron as a main component). The spindle 31 is supported by a bearing 316 held in the barrel portion 131 and a bearing 317 held by a movable support 18 described later.

Hereinafter, the drive mechanism 5 will be described. As shown in FIGS. 6 to 8, in the present embodiment, the drive mechanism 5 includes a striking mechanism 6 and a rotation transmission mechanism 7. The striking mechanism 6 is a mechanism for performing a hammering motion, and is configured to convert the rotational motion of the first intermediate shaft 41 into a linear motion and drive the tip tool 91 linearly along the drive shaft A1. Has been done. The rotation transmission mechanism 7 is a mechanism for performing a drill operation, and is configured to transmit the rotational movement of the second intermediate shaft 42 to the spindle 31 and rotationally drive the tip tool 91 around the drive shaft A1. There is. Hereinafter, the detailed configurations of the striking mechanism 6 and the rotation transmission mechanism 7 will be described in order.

In this embodiment, as shown in FIGS. 6 and 7, the striking mechanism 6 includes a motion conversion member 61, a piston 65, a striker 67, and an impact bolt 68.

The motion conversion member 61 is arranged on the first intermediate shaft 41, and is configured to convert the rotational motion of the first intermediate shaft 41 into a linear motion and transmit it to the piston 65. More specifically, the motion conversion member 61 includes a rotating body 611 and a swing member 616. The rotating body 611 is rotatably supported around the rotating shaft A3 with respect to the main body housing 10 by the bearing 614. The swing member 616 is rotatably attached to the outer periphery of the rotating body 611, and is configured to swing in the extending direction (front-back direction) of the rotating shaft A3 as the rotating body 611 rotates. The swing member 616 has an arm portion 617 extending upward from the rotating body 611.

The piston 65 is a bottomed cylindrical member, and is slidably arranged in the cylinder 33 of the spindle 31 along the drive shaft A1. The piston 65 is connected to the arm portion 617 of the swing member 616 via a connecting pin, and is reciprocated in the front-rear direction as the swing member 616 swings.

The striker 67 is a striking element for applying a striking force to the tip tool 91. The striker 67 is slidably arranged in the piston 65 along the drive shaft A1. The internal space of the piston 65 on the rear side of the striker 67 is defined as an air chamber that functions as an air spring. The impact bolt 68 is a meson that transmits the kinetic energy of the striker 67 to the tip tool 91. The impact bolt 68 is movably arranged in the tool holder 32 on the front side of the striker 67 along the drive shaft A1. In the present embodiment, the impact bolt 68 is slidably held in the front-rear direction by the guide sleeve 36 and the regulation ring 35 arranged in the tool holder 32.

When the piston 65 is moved in the front-rear direction along with the swing of the swing member 616, the pressure of the air in the air chamber fluctuates, and the striker 67 slides in the piston 65 in the front-rear direction by the action of the air spring. .. More specifically, when the piston 65 is moved forward, the air in the air chamber is compressed and the internal pressure rises. The striker 67 is pushed forward at high speed by the action of the air spring and hits the impact bolt 68. The impact bolt 68 transmits the kinetic energy of the striker 67 to the tip tool 91. As a result, the tip tool 91 is driven linearly along the drive shaft A1. On the other hand, when the piston 65 is moved rearward, the air in the air chamber expands and the internal pressure drops, and the striker 67 is pulled in rearward. The tip tool 91 moves backward together with the impact bolt 68 by being pressed against the workpiece. In this way, the hammering operation is repeated by the striking mechanism 6.

In the present embodiment, the rotational motion of the first intermediate shaft 41 is transmitted to the motion conversion member 61 (specifically, the rotating body 611) via the first transmission member 64 and the intervening member 63. Hereinafter, the intervening member 63 and the first transmission member 64 will be described in order.

As shown in FIGS. 6 and 9, the intervening member 63 is arranged coaxially with the first intermediate shaft 41 around the first intermediate shaft 41, and the first intermediate shaft 41 and the motion conversion member 61 (specifically, the motion conversion member 61). , A cylindrical member interposed between the rotating body 611). The intervening member 63 is immovable with respect to the first intermediate shaft 41 in the front-rear direction, while is rotatable around the rotation axis A3 with respect to the first intermediate shaft 41.

More specifically, the front end portion of the first intermediate shaft 41 (the portion adjacent to the rear side of the bearing 411 on the front side) is configured as the maximum diameter portion having the maximum outer diameter. A spline portion 416 is provided on the outer circumference of the maximum diameter portion. The spline portion 416 has a plurality of splines (external teeth) extending in the rotation axis A3 direction (front-rear direction). The intervening member 63 is held immovably in the front-rear direction between the spline portion 416 and the first driven gear 414 fixed to the rear end portion of the first intermediate shaft 41. The portion of the first intermediate shaft 41 adjacent to the rear side of the spline portion 416 is configured as a large diameter portion 417 having an outer diameter slightly larger than that of the portion further rearward.

Further, a spline portion 631 over the entire length of the intervening member 63 is provided on the outer periphery of the intervening member 63. The spline portion 631 has a plurality of splines (external teeth) extending in the rotation axis A3 direction (front-rear direction). The diameter of the spline portion 631 of the intervening member 63 is larger than the diameter of the spline portion 416 of the first intermediate shaft 41.

On the other hand, a spline portion 612 is formed on the inner circumference of the rotating body 611. The spline portion 612 has a spline (internal tooth) that engages with the spline portion 631. The intervening member 63 is always spline-engaged with the rotating body 611 and is held by the rotating body 611. With such a configuration, the rotating body 611 can move in the rotation axis A3 direction (front-rear direction) with respect to the intervening member 63 and the first intermediate shaft 41, and can rotate integrally with the intervening member 63. ..

The first transmission member 64 is arranged on the first intermediate shaft 41, can rotate integrally with the first intermediate shaft 41, and has a rotation axis A3 direction (front-rear direction) with respect to the first intermediate shaft 41 and the intervening member 63. ) Is configured to be movable.

More specifically, the first transmission member 64 is a substantially cylindrical member arranged around the first intermediate shaft 41, and a first spline portion 641 and a first spline portion 641 are formed on the inner circumference of the first transmission member 64. A second spline portion 642 is provided.

The first spline portion 641 is provided at the rear end portion of the first transmission member 64. The first spline portion 641 has a plurality of splines (internal teeth) that can be engaged with the spline portion 631 of the intervening member 63. As described above, the spline portion 631 of the intervening member 63 is also engaged with the spline portion 612 of the rotating body 611. That is, the spline portion 631 is effectively used for engaging with the two members of the rotating body 611 and the first transmission member 64. The second spline portion 642 is provided in the first half portion of the first transmission member 64. The second spline portion 642 has a plurality of splines (internal teeth) that are always engaged with the spline portion 416 of the first intermediate shaft 41.

With such a configuration, as shown by a solid line in FIG. 9, the first spline portion 641 is arranged at a position where the first spline portion 641 engages with the spline portion 631 of the intervening member 63 (hereinafter, referred to as an engagement position) in the front-rear direction. In this case, the first transmission member 64 can rotate integrally with the intervening member 63, that is, power can be transmitted from the first intermediate shaft 41 to the intervening member 63. In the present embodiment, the diameter of the first spline portion 641 is larger than the diameter of the second spline portion 642. By increasing the diameter of the first spline portion 641 in this way, efficient torque transmission can be performed.

On the other hand, as shown by the dotted line in FIG. 9, when the first spline portion 641 is arranged at a position (hereinafter referred to as a separation position) separated from the spline portion 631 (hereinafter referred to as a separated position), the first transmission member 64 is , The power transmission from the first intermediate shaft 41 to the intervening member 63 is disabled (blocked).

The diameter of the large diameter portion 417 of the first intermediate shaft 41 is set to be slightly smaller than the inner diameter of the intervening member 63. Therefore, the gap between the inner circumference of the intervening member 63 and the outer circumference of the large diameter portion 417 of the first intermediate shaft 41 is very small. As a result, when the first transmission member 64 moves from the separated position to the engaged position, smooth engagement between the second spline portion 642 and the spline portion 631 can be realized. On the other hand, a larger gap is secured between the inner circumference of the intervening member 63 and the outer circumference of the portion other than the large diameter portion 417. As a result, when the power transmission from the first intermediate shaft 41 to the intervening member 63 is cut off, the co-rotation between the first intermediate shaft 41 and the intervening member 63 can be more reliably suppressed.

As described above, in the present embodiment, the first transmission member 64 and the intervening member 63 function as the first clutch mechanism 62 that transmits or cuts off the power for the hammer operation. In the present embodiment, the first transmission member 64 is connected to the mode switching mechanism 80 (see FIG. 12), and is set to the engaging position according to the operation of the mode switching dial 800 (see FIG. 2) by the user. Moved between separated positions. That is, the first clutch mechanism 62 is switched between the power transmission state and the cutoff state according to the operation of the mode switching dial 800. The mode switching mechanism 80 will be described in detail later.

As shown in FIG. 8, in the present embodiment, the rotation transmission mechanism 7 includes a drive gear 78 and a driven gear 79. The drive gear 78 is fixed to the front end portion of the second intermediate shaft 42 (the portion adjacent to the rear side of the bearing 421 on the front side). The driven gear 79 is fixed to the outer circumference of the cylinder 33 of the spindle 31 and meshes with the drive gear 78. The drive gear 78 and the driven gear 79 form a gear reduction mechanism. As the drive gear 78 rotates integrally with the second intermediate shaft 42, the spindle 31 rotates integrally with the driven gear 79. As a result, the drill operation in which the tip tool 91 held by the tool holder 32 is rotationally driven around the drive shaft A1 is performed.

As described above, in the present embodiment, the rotational movement of the second driven gear 424, which is rotated with the rotation of the motor shaft 25, is the second intermediate shaft 42 via the second transmission member 72 and the torque limiter 73. Is transmitted to. Hereinafter, the torque limiter 73 and the second transmission member 72 will be described in order.

As shown in FIGS. 6 and 10, the torque limiter 73 is arranged on the second intermediate shaft 42 and is configured to block transmission when the torque acting on the second intermediate shaft 42 exceeds a threshold. It is a clutch mechanism. In the present embodiment, the torque limiter 73 includes a drive side member 74, a driven side member 75, a ball 76, and an urging spring 77.

The drive-side member 74 is a cylindrical member and is rotatably supported by the latter half of the second intermediate shaft 42. The second driven gear 424 is rotatably supported by the rear end portion of the drive side member 74. Therefore, the drive side member 74 can rotate around the rotation shaft A4 with respect to the second intermediate shaft 42 and the second driven gear 424.

The drive-side member 74 includes a cam recess 742 (see FIG. 11) and a spline portion 743. The cam recess 742 is provided at the front end of the drive side member 74 and has a cam surface that is inclined in the circumferential direction. The spline portion 743 is provided on the outer periphery of the drive side member 74 on the rear side of the cam recess 742, and has a plurality of splines (external teeth) extending in the rotation axis A4 direction (front-rear direction).

The driven side member 75 is a cylindrical member, which is arranged on the front side of the drive side member 74 and around the second intermediate shaft 42. A plurality of grooves 751 extending in the rotation axis A4 direction (front-rear direction) are provided on the inner circumference of the driven side member 75 in the circumferential direction. Further, a plurality of grooves 426 extending in the rotation axis A4 direction (front-rear direction) are provided on the outer periphery of the second intermediate shaft 42 in the circumferential direction. The ball 76 is tumblably housed in a trajectory defined by the groove 426 and the groove 751. As a result, the driven side member 75 engages with the second intermediate shaft 42 via the ball 76 in the radial direction and the circumferential direction, and is made rotatable integrally with the second intermediate shaft 42. Further, the driven side member 75 can move in the front-rear direction with respect to the second intermediate shaft 42 within a range in which the ball 76 can roll in the orbit.

The driven side member 75 has a cam protrusion 752 (see FIG. 11) provided at the rear end. The cam protrusion 752 has a shape that substantially matches the cam recess 742 of the drive side member 74, and has a cam surface that is inclined in the circumferential direction. The urging spring 77 is a compression coil spring, and is arranged in a compressed state between the drive gear 78 and the driven side member 75. Therefore, the urging spring 77 always urges the driven side member 75 in the direction close to the driving side member 74, that is, in the direction (rear) in which the cam protrusion 752 and the cam recess 742 mesh with each other. When the cam protrusion 752 and the cam recess 742 are engaged with each other, torque can be transmitted from the drive side member 74 to the driven side member 75, and eventually the second intermediate shaft 42 can rotate. The drive side member 74 and the gear member 423 are urged rearward via the driven side member 75 and are held at the rearmost position with respect to the second intermediate shaft 42.

As shown in FIG. 11, when a load equal to or higher than the threshold value is applied to the second intermediate shaft 42 via the tool holder 32 (spindle 31) because the tip tool 91 is locked during the rotation of the second intermediate shaft 42. In addition, the meshing engagement between the cam protrusion 752 and the cam recess 742 is released. More specifically, due to the action of the cam surface (inclined surface) of the cam protrusion 752 and the cam recess 742, the cam protrusion 752 is separated from the cam recess 742 to resist the urging force of the urging spring 77, and the drive side member 74. Ride on the front end face of. That is, the driven side member 75 moves in the direction (forward) away from the driving side member 74. At this time, the driven side member 75 can smoothly move forward by being guided by the ball 76 that rolls with the second intermediate shaft 42. As a result, the torque transmission from the drive side member 74 to the driven side member 75 is cut off, and the rotation of the second intermediate shaft 42 is interrupted.

As shown in FIGS. 6 and 10, the second transmission member 72 is arranged on the second intermediate shaft 42, can rotate integrally with the drive side member 74 of the torque limiter 73, and has the drive side member 74 and the gear. It is configured to be movable in the rotation axis A4 direction (front-back direction) with respect to the member 423.

More specifically, the second transmission member 72 is a substantially cylindrical member arranged around the drive side member 74, and the first spline portion 721 and the first spline portion 721 are formed on the inner circumference of the second transmission member 72. Two spline portions 722 are provided. The first spline portion 721 is provided in the first half portion of the second transmission member 72. The first spline portion 721 has a plurality of splines (internal teeth) that are always engaged with the spline portion 743 of the drive side member 74. The second spline portion 722 is provided at the rear end portion of the second transmission member 72 and has an inner diameter larger than that of the first spline portion 721. The second spline portion 722 has a plurality of splines (internal teeth) that can be engaged with the spline portion 425 of the gear member 423.

With such a configuration, as shown by a solid line in FIG. 10, the second spline portion 722 is arranged at a position where the second spline portion 722 engages with the spline portion 425 of the gear member 423 (hereinafter referred to as an engagement position) in the front-rear direction. In this case, the second transmission member 72 can rotate integrally with the gear member 423. Therefore, the drive side member 74 spline-engaged with the second transmission member 72 can also rotate integrally with the gear member 423. On the other hand, as shown by the dotted line in FIG. 10, when the second spline portion 722 is arranged at a position (hereinafter referred to as a separation position) separated from the spline portion 425 (hereinafter referred to as an disengaged position), the second transmission member 72 , The power transmission from the gear member 423 to the drive side member 74 is disabled (blocked).

As described above, in the present embodiment, the second transmission member 72 and the gear member 423 function as the second clutch mechanism 71 that transmits or cuts off the power for the drill operation. In the present embodiment, the second transmission member 72 is connected to the mode switching mechanism 80 (see FIG. 12) like the first transmission member 64, and the mode switching dial 800 (see FIG. 2) by the user. It is moved between the engaged position and the separated position according to the operation. That is, the second clutch mechanism 71, like the first clutch mechanism 62, can be switched between the power transmission state and the cutoff state according to the operation of the mode switching dial 800.

Hereinafter, the mode switching dial 800 and the mode switching mechanism 80 will be described.

As shown in FIGS. 12 to 14, the mode switching mechanism 80 is a mechanism configured to switch the operation mode of the hammer drill 101 in conjunction with the mode switching dial 800. In this embodiment, the hammer drill 101 has three operation modes: a hammer drill mode, a hammer mode, and a drill mode. The hammer drill mode is an operation mode in which a hammer operation and a drill operation are performed by driving both the striking mechanism 6 and the rotation transmission mechanism 7. The hammer mode is an operation mode in which only the hammer operation is performed by blocking the power transmission for the drill operation by the second clutch mechanism 71 and driving only the striking mechanism 6. The drill mode is an operation mode in which only the drill operation is performed by blocking the power transmission for the hammer operation by the first clutch mechanism 62 and driving only the rotation transmission mechanism 7.

As shown in FIGS. 2 and 12 to 14, the mode switching dial 800 is provided at the lower end of the main body housing 10 (specifically, the front housing 13) so that the user can operate it externally. The mode switching dial 800 includes a disk-shaped operation unit 801 having a knob, and first pin 803 and second pin 805 protruding from the operation unit 801.

The operation unit 801 is rotatably held around a rotation axis extending in the vertical direction by the main body housing 10. A part of the operation unit 801 is partially exposed to the outside through an opening formed in the lower wall of the main body housing 10 (front housing 13) so that the user can rotate the operation unit 801. The mode switching dial 800 is defined with rotation positions corresponding to the hammer drill mode, the hammer mode, and the drill mode, respectively. The user can set the operation mode by arranging the mode switching dial 800 at the rotation position corresponding to the desired operation mode. The first pin 803 and the second pin 805 project upward from the upper surface of the operation unit 801. The first pin 803 and the second pin 805 move on the circumference around the rotation axis of the operation unit 801 with the rotation of the mode switching dial 800.

The mode switching mechanism 80 includes a first switching member 81, a second switching member 82, a first spring 83, and a second spring 84.

The first switching member 81 has a pair of support holes (not shown), and is supported so as to be movable in the front-rear direction by a support shaft 88 inserted through the support holes. The support shaft 88 is a shaft that is fixed to the bearing support 15 and projects forward from the bearing support 15. The support shaft 88 extends parallel to the first intermediate shaft 41 and the second intermediate shaft 42. A retaining ring 881 is fixed to the central portion of the support shaft 88 in the axial direction. The first switching member 81 is supported on the front side of the retaining ring 881. The second switching member 82 has a pair of support holes (not shown), and is supported by a support shaft 88 inserted through the support holes so as to be movable in the front-rear direction on the rear side of the retaining ring 881.

The first switching member 81 and the second switching member 82 are engaged with the first transmission member 64 and the second transmission member 72, respectively. More specifically, annular grooves 645 and 725 are provided on the outer circumferences of the first transmission member 64 and the second transmission member 72, respectively. The first switching member 81 is engaged with the first transmission member 64 via a plate-shaped first engaging portion 813 (see FIG. 14) arranged in the groove 645. Similarly, the second switching member 82 is engaged with the second transmission member 72 via a plate-shaped second engaging portion 823 (see FIG. 10) arranged in the groove 725. In the first transmission member 64 and the second transmission member 72, the first switching member 81 and the second switching member 81 and the second transmission member 72 are in a state where the first engaging portion 813 and the second engaging portion 823 are engaged with the grooves 645 and 725, respectively. It is rotatable with respect to the switching member 82.

The first spring 83 is a compression coil spring, which is arranged in a compressed state between the front housing 13 and the first switching member 81, and always urges the first switching member 81 rearward. As a result, the first transmission member 64 engaged with the first switching member 81 is also always urged toward the rear engaging position. The second spring 84 is a compression coil spring, which is arranged in a compressed state between the retaining ring 881 fixed to the support shaft 88 and the second switching member 82, and the second switching member 82 is always attached to the rear. It is gaining momentum. As a result, the second transmission member 72 engaged with the second switching member 82 is also always urged toward the rear engaging position. The rearmost position of the first switching member 81 is a position where the first switching member 81 comes into contact with the retaining ring 881. The rearmost position of the second switching member 82 is a position where the second switching member 82 abuts on the front surface of the bearing support 15.

When the mode switching dial 800 is arranged at the rotation position corresponding to the hammer drill mode shown in FIG. 12 (hereinafter referred to as the hammer drill position), the first pin 803 is the first switching member 81 arranged at the rearmost position. The second pin 805 is arranged at a position adjacent to the rear of the second switching member 82, and is arranged at a position adjacent to the rear of the second switching member 82 arranged at the rearmost position. At this time, the first transmission member 64 is arranged at an engaging position where the second spline portion 642 engages with the spline portion 631 of the intervening member 63 (see FIG. 9), and the first clutch mechanism 62 is in the power transmission state. Be placed. Further, the second transmission member 72 is arranged at an engaging position where the second spline portion 722 engages with the spline portion 425 of the gear member 423 (see FIG. 10), and the second clutch mechanism 71 is also placed in the power transmission state. Be taken.

When the motor 2 is energized, power is transmitted from the motor shaft 25 to the striking mechanism 6 via the first intermediate shaft 41, and a hammer operation is performed. At the same time, power is transmitted from the motor shaft 25 to the rotation transmission mechanism 7 via the second intermediate shaft 42, and the drill operation is also executed.

When the mode switching dial 800 is rotated from the hammer drill position shown in FIG. 12 to the rotation position corresponding to the hammer mode shown in FIG. 13 (hereinafter referred to as the hammer position), the second pin 805 is switched to the second pin 805. The second switching member 82 is moved forward against the urging force of the second spring 84 while moving clockwise in a state of being in contact with the member 82 from the rear. When the mode switching dial 800 is arranged at the hammer position, the second switching member 82 is arranged at the frontmost position. With the movement of the second switching member 82, the second transmission member 72 is moved from the engaged position to the separated position (see FIG. 10), and the second clutch mechanism 71 is switched to the cutoff state.

On the other hand, the first pin 803 moves clockwise in the bottom view without interfering with the first switching member 81 or the second switching member 82, and is separated from the first switching member 81 and the second switching member 82. It is placed in the desired position. Therefore, during this period, the first switching member 81 and the first transmission member 64 do not move, and the first clutch mechanism 62 is maintained in the power transmission state.

Even if the motor 2 is energized, the power is not transmitted from the motor shaft 25 to the second intermediate shaft 42, so that the drill operation is not performed. On the other hand, since power is transmitted from the motor shaft 25 to the striking mechanism 6 via the first intermediate shaft 41, only the hammer operation is performed.

When the mode switching dial 800 is rotated from the hammer drill position shown in FIG. 12 to the rotation position corresponding to the drill mode shown in FIG. 14 (hereinafter referred to as the drill position), the first pin 803 is first switched. The first switching member 81 is moved forward against the urging force of the first spring 83 while abutting the member 81 from the rear and moving counterclockwise around the rotation axis of the operation unit 801 when viewed from the bottom. Let me. When the mode switching dial 800 is arranged at the drill position, the first switching member 81 is arranged at the frontmost position. With the movement of the first switching member 81, the first transmission member 64 is moved from the engaged position to the separated position (see FIG. 9), and the first clutch mechanism 62 is switched to the disengaged state.

On the other hand, the second pin 805 moves in the counterclockwise direction around the rotation axis of the operation unit 801 in the bottom view without interfering with the first switching member 81 or the second switching member 82, and the second pin 805 is second. It is arranged at a position adjacent to the switching member 82. Therefore, during this period, the second switching member 82 and the second transmission member 72 do not move, and the second clutch mechanism 71 is maintained in the power transmission state.

Even if the motor 2 is energized, the hammer operation is not performed because the power is not transmitted from the first intermediate shaft 41 to the motion conversion member 61. On the other hand, since power is transmitted from the motor shaft 25 to the rotation transmission mechanism 7 via the second intermediate shaft 42, only the drill operation is performed.

As described above, the hammer drill 101 of the present embodiment has two separate intermediate shafts (first intermediate shafts) extending parallel to the drive shaft A1 and transmitting power for hammer operation and drill operation, respectively. 41 and a second intermediate shaft 42) are provided. Therefore, the first intermediate shaft 41 and the second intermediate shaft 42 can be shortened as compared with the case where one common intermediate shaft is adopted for the power transmission for the hammer operation and the drill operation. As a result, the length of the entire hammer drill 101 in the drive axis direction can be shortened. Further, by shortening the first intermediate shaft 41 and the second intermediate shaft 42, the center of gravity of the hammer drill 101 can be brought closer to the handle 17 connected to the rear end portion of the main body housing 10, and the operability can be improved. ..

Further, the first intermediate shaft 41 and the second intermediate shaft 42 are specialized in power transmission for hammer operation and power transmission for drill operation, respectively. That is, the power transmission path dedicated to the hammer operation and the power transmission path dedicated to the drill operation are provided in parallel, not in series. Therefore, the power transmission from the first intermediate shaft 41 to the first drive mechanism and the power transmission from the second intermediate shaft 42 to the second drive mechanism and eventually to the spindle 31 as the final output shaft should be optimized respectively. Can be done.

Further, since the motion conversion member 61 is mounted on the first intermediate shaft 41 dedicated to the hammer operation, a certain length is required. On the other hand, the drive gear 78 mounted on the second intermediate shaft 42 dedicated to the drill operation does not need to have such a length. Therefore, in the present embodiment, the torque limiter 73 is arranged by effectively utilizing the space generated on the second intermediate shaft 42. The second intermediate shaft 42 has a lower transmission torque than the spindle 31 as the final output shaft. Therefore, the torque limiter 73, which is smaller and lighter than the torque limiter mounted on the spindle 31, can be adopted. Further, the torque limiter 73 of the present embodiment can guide the driven side member 75 in the rotation axis A4 direction while the ball 76 rolls when the torque limiter 73 operates. As a result, the friction between the driven side member 75 and the second intermediate shaft 42 can be reduced, and the operating torque can be stabilized.

Further, in the present embodiment, the first intermediate shaft 41 and the second intermediate shaft 42 are provided with the first clutch mechanism 62 and the second clutch mechanism 71, respectively. Therefore, the power for the hammer operation and the power for the drill operation can be cut off as needed. Further, both the first clutch mechanism 62 and the second clutch mechanism 71 are switched between the power transmission state and the cutoff state according to the operation of the same operation member (mode switching dial 800). Therefore, the user can operate the first clutch mechanism 62 and the second clutch mechanism 71 simply by operating the mode switching dial 800 according to the desired work and switching the operation mode.

By the way, as shown in FIGS. 6 and 12 to 14, the hammer drill 101 is provided with a lock plate 45 configured to regulate the rotation of the second intermediate shaft 42 in the hammer mode. This is to prevent the tip tool 91 held by the tool holder 32 from freely rotating during the hammer operation.

The lock plate 45 is configured to engage with the second transmission member 72 arranged at a separated position to regulate the rotation of the second transmission member 72. The lock plate 45 is a long metal member. The lock plate 45 is urged rearward by the urging spring 46, and is moved in the front-rear direction by ribs 137 (only partially shown in FIGS. 5 and 15 to 17) provided in the front housing 13. It is held slidable. The urging spring 46 is a compression coil spring, and its front end portion is arranged in a recess 138 (see FIGS. 15 to 17) provided in the front housing 13.

The lock plate 45 includes a spring receiving portion 451, an abutting portion 453, and a locking portion 455. The spring receiving portion 451 is a protrusion provided at the front end portion of the lock plate 45, and is inserted into the rear end portion of the urging spring 46. The contact portion 453 is a portion extending rearward along the inner peripheral surface of the front housing 13 on the radial outer side of the torque limiter 73 and the second transmission member 72. The lock plate 45 is urged rearward by the urging spring 46, and the rear end surface of the contact portion 453 abuts on the front end surface of the protrusion 157 protruding forward from the front surface of the bearing support 15 (initial position). It is held. The locking portion 455 is a substantially rectangular portion arranged on the front side of the second transmission member 72. On the other hand, a plurality of recesses 727 are provided at the front end of the second transmission member 72. The recesses 727 are substantially rectangular recesses that are recessed rearward from the front end of the second transmission member 72, and are provided at equal intervals in the circumferential direction.

As described above, in the hammer drill mode and the drill mode, the second transmission member 72 is arranged at the engaging position. At this time, as shown in FIGS. 12 and 14, the locking portion 455 of the lock plate 45 is located at a position separated forward from the second transmission member 72. Therefore, the second transmission member 72 can rotate together with the first driven gear 414 without being interfered by the lock plate 45.

On the other hand, as shown in FIG. 13, in the hammer mode, the second transmission member 72 is arranged at a separated position in front of the engaging position, and the locking portion 455 of the lock plate 45 is the second transmission member 72. Engage in one of a plurality of recesses 727. As a result, the rotation of the second transmission member 72 is regulated, so that the rotation of the drive side member 74, the driven side member 75, and the second intermediate shaft 42 is also regulated. Then, the rotation of the spindle 31 is also regulated via the drive gear 78 and the driven gear 79.

In the process of moving the second transmission member 72 from the engaging position to the separating position, if the locking portion 455 does not face the recess 727, the front end surface of the second transmission member 72 becomes the locking portion 455. It abuts and moves the lock plate 45 forward against the urging force of the urging spring 46. After that, the tip tool 91 is rotated, and when the second transmission member 72 is rotated to a position where the locking portion 455 and the recess 727 face each other via the spindle 31 and the second intermediate shaft 42, the urging spring 46 is used. The lock plate 45 is urged to move rearward, and the locking portion 455 engages with the recess 727.

By the way, in the present embodiment, the hammer drill 101 suppresses the vibration generated by driving the drive mechanism 5 (particularly, the vibration in the drive axis direction (front-rear direction)) being transmitted to the main body housing 10 and the handle 17. It is configured in. Hereinafter, the anti-vibration structure of the hammer drill 101 will be described.

In the present embodiment, as shown in FIG. 2, the spindle 31 and the striking mechanism 6 (specifically, the motion conversion member 61, the piston 65, the striker 67, and the impact bolt 68) are attached to the main body housing 10 inside the main body housing 10. On the other hand, it is arranged so as to be movable in the drive axis direction (front-back direction). More specifically, inside the main body housing 10, a movable support 18 that can move in the front-rear direction with respect to the main body housing 10 is arranged in a state of being urged forward with respect to the main body housing 10. The spindle 31 and the striking mechanism 6 are supported by the movable support 18, so that the spindle 31 and the striking mechanism 6 can move integrally with the movable support 18 with respect to the main body housing 10.

As shown in FIGS. 5, 7, 15 and 16, the movable support 18 includes a spindle support portion 185, a rotating body support portion 187, a first shaft insertion portion 181 and a second shaft insertion portion 182. In the present embodiment, the movable support 18 is configured as a single metal member.

The spindle support portion 185 is formed in a substantially cylindrical shape, and is configured as a portion that supports the spindle 31. A bearing 317 is held inside the spindle support portion 185. The spindle support portion 185 rotatably supports the rear portion of the cylinder 33 around the drive shaft A1 via the bearing 317. As described above, the spindle 31 is rotatably supported around the drive shaft A1 with respect to the main body housing 10 by the bearings 316 and 317. The other bearing 316 is held in the barrel portion 131, and supports the rear portion of the tool holder 32 so as to be rotatable around the drive shaft A1 and movable in the front-rear direction.

The rotating body support portion 187 is a portion formed in a substantially cylindrical shape, and is connected below the right end portion of the spindle support portion 185. A bearing 614 is fixed to the rotating body support portion 187 by a screw. The rotating body support portion 187 rotatably supports the rotating body 611 around the rotating shaft A3 via the bearing 614.

As described above, since the spindle 31 and the rotating body 611 are supported by the movable support 18, the swinging member 616 attached to the rotating body 611, and the piston 65 and the striker 67 arranged in the spindle 31. And the impact bolt 68 is also supported by the movable support 18. Therefore, the movable support 18, the spindle 31, and the striking mechanism 6 form a movable unit 180 as an assembly that can be integrally moved in the front-rear direction with respect to the main body housing 10.

The first shaft insertion portion 181 and the second shaft insertion portion 182 are arranged on the right side and the left side of the spindle support portion 185, respectively, symmetrically with respect to the reference plane VP. The first shaft insertion portion 181 has a pair of cylindrical portions 183. The pair of cylindrical portions 183 are provided coaxially apart from each other in the front-rear direction. A bearing 184 is fitted in each cylindrical portion 183. In the present embodiment, a cylindrical oil-free bearing is adopted as the bearing 184. The second shaft insertion portion 182 has the same configuration as the first shaft insertion portion 181. That is, the second shaft insertion portion 182 has a pair of cylindrical portions 183 in which the bearing 184 is fixed.

As shown in FIGS. 5 and 15, the movable support 18 (movable unit 180) is movably supported by the first guide shaft 191 and the second guide shaft 192 with respect to the main body housing 10 in the front-rear direction. The first guide shaft 191 and the second guide shaft 192 are arranged symmetrically with respect to the reference plane VP, and extend in parallel (in the front-rear direction) with the drive shaft A1 in the upper part of the front housing 13. The front ends of the first guide shaft 191 and the second guide shaft 192 are fixedly held by the front housing 13, and the rear ends are fixedly held by the bearing support 15. Therefore, the first guide shaft 191 and the second guide shaft 192 are immovable with respect to the main body housing 10.

In the present embodiment, the first guide shaft 191 and the second guide shaft 192 are both made of iron (or an alloy containing iron as a main component). The first guide shaft 191 and the second guide shaft 192 are slidably inserted into a pair of front and rear bearings 184 of the first shaft insertion portion 181 and the second shaft insertion portion 182, respectively. That is, the inner peripheral surface of the bearing 184 defines the support holes 190 of the first guide shaft 191 and the second guide shaft 192. With such a configuration, the movable support 18 (movable unit 180) can move in the front-rear direction with respect to the main body housing 10 while being guided by the first guide shaft 191 and the second guide shaft 192.

Further, as described above, the first intermediate shaft 41 for hammer operation and the second intermediate shaft 42 for drill operation are held by the bearings 411 and 421 held in the front housing 13 and the bearing support 15, respectively. The bearings 412 and 422 are immovably supported in the front-rear direction with respect to the main body housing 10. Therefore, the movable support 18 (movable unit 180) can also move in the front-rear direction with respect to the first intermediate shaft 41 and the second intermediate shaft 42.

In the present embodiment, the movable support 18 supports the spindle 31 and the striking mechanism 6 and receives a load during the hammer operation. Therefore, in order to secure both strength and reduce the weight, an aluminum alloy or a magnesium alloy is used. It is formed. On the other hand, the bearing 184 that slides on the first guide shaft 191 and the second guide shaft 192 is formed of a material having better lubricity than the movable support 18. In the movable support 18, the portion defining the support hole 190 of the first guide shaft 191 and the second guide shaft 192 (that is, the portion sliding with the first guide shaft 191 and the second guide shaft 192) is The bearing does not have to be 184. For example, only the cylindrical portion defining the support hole 190 is made of a material different from the other portion of the movable support 18 (for example, iron or an alloy containing iron as a main component) and is integrally formed with the other portion. It may have been done.

A first urging spring 194 and a second urging spring 195 are arranged on the rear side of each of the first shaft insertion portion 181 and the second shaft insertion portion 182. The first urging spring 194 and the second urging spring 195 are both compression coil springs, and are respectively mounted on the first guide shaft 191 and the second guide shaft 192, and the movable support 18 and the bearing support 15 are attached to each other. It is arranged in a compressed state between them. More specifically, the front end of the first urging spring 194 is in contact with the rear end of the cylindrical portion 183 on the rear side of the first shaft insertion portion 181 via a washer. The rear end of the first urging spring 194 is fitted into a spring receiving portion provided on the front surface of the bearing support 15. Similarly, the front end of the second urging spring 195 is in contact with the rear end of the cylindrical portion 183 on the rear side of the second shaft insertion portion 182 via a washer. The rear end of the second urging spring 195 is fitted into a spring receiving portion provided on the front surface of the bearing support 15.

With such a configuration, the first urging spring 194 and the second urging spring 195 always urge the movable support 18 (movable unit 180) forward. Therefore, in the movable support 18, when an external force toward the rear is not applied to the movable support 18 (movable unit 180), the first shaft insertion portion 181 and the cylindrical portion 183 on the front side of the second shaft insertion portion 182 are formed. , It is held at the foremost position (initial position) where it abuts on the shoulder portion 133 provided in the front housing 13. That is, the shoulder portion 133 functions as a stopper that prevents the movable support 18 (movable unit 180) from further moving forward.

On the other hand, as shown in FIGS. 5 and 17, a pair of left and right cushioning members 197 are provided on the front surface side of the bearing support 15 as stoppers for restricting further rearward movement of the movable support 18 (movable unit 180). Is provided. More specifically, a pair of left and right cylindrical protrusions 155 are provided on the front surface of the bearing support 15 symmetrically with respect to the reference surface VP. The protrusion 155 projects forward so as to face the upper end portion of the movable support 18 (specifically, the portion adjacent to the first shaft insertion portion 181 and the second shaft insertion portion 182 on the reference surface VP side). Each cushioning member 197 is made of columnar rubber and is fitted to each protrusion 155.

The cushioning member 197 protrudes forward from the front end of the protrusion 155 when no external force is applied. When the movable support 18 (movable unit 180) is in the foremost position (position in FIG. 17), the cushioning member 197 is in a position separated rearward from the movable support 18. In the cushioning member 197, the movable support 18 (movable unit 180) moves rearward with respect to the main body housing 10, and the first urging spring 194 and the second urging spring 195 (see FIG. 15) are compressed by a predetermined amount. And, it is configured to come into contact with the movable support 18 from the rear.

By the way, in the present embodiment, the first guide shaft 191 and the second guide shaft 192 shown in FIGS. 5 and 15 both have a circular cross section, but have different diameters. More specifically, the diameter of the second guide shaft 192 on the left side is slightly smaller than the diameter of the first guide shaft 191 on the right side with respect to the reference plane VP. On the other hand, the total of four cylindrical portions 183 and the bearing 184 of the first shaft insertion portion 181 and the second shaft insertion portion 182 all have the same configuration. That is, the diameter of the support hole 190 of the first guide shaft 191 and the diameter of the support hole 190 of the second guide shaft 192 are the same.

Therefore, the gap formed between the outer peripheral surface of the second guide shaft 192 on the left side with respect to the reference surface VP and the inner peripheral surface of the pair of bearings 184 of the second shaft insertion portion 182 is on the right side. It is slightly larger than the gap formed between the outer peripheral surface of the first guide shaft 191 and the inner peripheral surface of the pair of bearings 184 of the first shaft insertion portion 181. That is, the clearance with respect to the second guide shaft 192 is slightly larger than the clearance with respect to the first guide shaft 191. The bearings 184 of the first guide shaft 191 and the first shaft insertion portion 181 are set to have higher dimensional accuracy, and the bearings 184 of the first guide shaft 191 and the first shaft insertion portion 181 are substantially spaced apart from each other. It is configured to fit tightly.

If both the first guide shaft 191 and the second guide shaft 192 are to be fitted into the respective support holes 190 as closely as possible, the first guide shaft 191 and the second guide shaft 192 and / or the respective support holes 190 are to be fitted. Assembling may be difficult due to the error of. On the other hand, according to the configuration of the present embodiment as described above, the guide function of the movable support 18 is well maintained by forming the gap between the first guide shaft 191 and the bearing 184 with high accuracy. However, it can be easily assembled.

Of the first guide shaft 191 and the second guide shaft 192, the guide shaft having a smaller clearance (higher dimensional accuracy) (hereinafter referred to as the reference guide shaft) is a drive gear when the movable unit 180 rotates. It is preferable that the determination is made in consideration of the influence on the meshing of 78 and the driven gear 79 (see FIG. 8). More specifically, assuming that the movable unit 180 rotates by the same angle around each axis of the first guide shaft 191 and the second guide shaft 192, the drive shaft A1 of the spindle 31 and the second intermediate It is preferable to select a guide shaft in which the change in the center distance of the shaft 42 from the rotating shaft A4 (the shortest distance between the driving shaft A1 and the rotating shaft A4) is smaller. This is because it is possible to make it difficult to affect the engagement between the drive gear 78 and the driven gear 79 when the movable unit 180 rotates.

Hereinafter, a method for determining the reference guide shaft will be specifically described with reference to FIG. FIG. 18 shows the pitches of the drive gear 78 and the driven gear 79 (see FIG. 8) on a plane orthogonal to the drive shaft A1 and the rotation shaft A4 when the drive gear 78 and the driven gear 79 are in an appropriate meshing state. The circles C1 and C2 and the common tangent T of the pitch circles C1 and C2 are shown. The point P is one point on the driven gear 79 that coincides with the pitch points of the drive gear 78 and the driven gear 79 at this time.

As described above, the drive gear 78 is provided on the second intermediate shaft 42 which cannot move in the axial direction and the radial direction with respect to the main body housing 10. On the other hand, the driven gear 79 provided on the spindle 31 is a part of the movable unit 180. Therefore, the driven gear 79 moves with respect to the drive gear 78 around the axis of the reference guide shaft as the movable unit 180 rotates. At this time, when the point P on the driven gear 79 moves in the extending direction of the common tangent line T with respect to the drive gear 78, the change in the center distance is relatively small and the meshing is relatively affected. It's hard to get out. On the contrary, when the point P moves in a direction substantially orthogonal to the common tangent line T, the larger the amount of movement, the larger the center distance changes, and the meshing is released or the meshing becomes deeper. It can be too much.

From the above, as shown by reference numeral S in FIG. 18, the reference guide shaft is driven on a straight line L passing through the rotating shaft A4 of the driving gear 78 and the driving shaft A1 which is the rotating shaft of the driven gear 79. It can be said that it is optimally arranged on the side opposite to the gear 78. When neither the first guide shaft 191 nor the second guide shaft 192 is on the straight line L, one of the first guide shaft 191 and the second guide shaft 192 that is closer to the straight line L is the reference guide shaft. It is preferable to be done. Specifically, on a plane orthogonal to the drive shaft A1 and the rotation shaft A4, the angle α formed by the line segment connecting the shaft of the first guide shaft 191 and the drive shaft A1 and the straight line L, and the second guide shaft 192. The line segment connecting the axis of No. 1 and the drive axis A1 and the angle β formed by the straight line L are compared. The guide shaft corresponding to one of the smaller angles α and β may be used as the reference shaft.

In the present embodiment, the drive shaft A1 and the first guide shaft 191 and the second guide shaft 192 are arranged in a straight line on a plane orthogonal to the drive shaft A1 and the rotation shaft A4. Therefore, the angle α1 and the angle β1 are the same. Therefore, regardless of which of the first guide shaft 191 and the second guide shaft 192 is determined as the reference guide shaft, the change in the center distance when the movable unit 180 rotates is the same. Therefore, the second guide shaft 192 may be used as the reference shaft instead of the first guide shaft 191. On the other hand, for example, when the positions of the first guide shaft 191 and the second guide shaft 192 are changed to the positions shown by the dotted lines in FIG. 18, the angle α2 becomes smaller than the angle β2. Therefore, in this case, it is preferable that the first guide shaft 191 is used as the reference guide shaft.

In the present embodiment, the first guide shaft 191 and the second guide shaft 192 have different diameters, but the first guide shaft 191 and the second guide shaft 192 may have the same diameter. In this case, the inner diameters of the pair of bearings 184 of the first shaft insertion portion 181 and the inner diameters of the pair of bearings 184 of the second shaft insertion portion 182 are made different so that the first guide shaft 191 and the second guide shaft 192 can be formed. The corresponding clearances can be different. Alternatively, the first guide shaft 191 and the second guide shaft 192 have different diameters, and the pair of bearings 184 of the first shaft insertion portion 181 and the pair of bearings 184 of the second shaft insertion portion 182 are formed. They may have different inner diameters from each other.

By the way, in the present embodiment, when assembling the internal structure to the front housing 13, a device is made to facilitate the assembling of the lock plate 45. Hereinafter, a method of assembling the lock plate 45 will be described with reference to FIGS. 19 to 21. In the present embodiment, the front housing 13 including the barrel portion 131 is configured as a single tubular member. Further, the lock plate 45 is positioned at the initial position by fitting the bearing support 15 into the rear end portion of the front housing 13. Therefore, after fitting the urging spring 46 into the recess 138, the operator simply engages the lock plate 45 with the rib 137 while inserting the spring receiving portion 451 into the urging spring 46, so that the operator can perform the bearing support 15 If the opening at the rear end of the front housing 13 is directed downward before fitting, the lock plate 45 and the urging spring 46 may fall off.

Therefore, in the present embodiment, as shown in FIG. 19, first, the spring receiving portion 451 is fixed in the rear end portion of the urging spring 46 by press fitting. Then, the lock plate 45 is fitted forward along the rib 137, and the front end portion of the urging spring 46 is fixed by press fitting into the recess 138 of the front housing 13. As a result, the lock plate 45 is temporarily fixed to the front housing 13 via the urging spring 46. Therefore, even if the operator turns the rear end of the front housing 13 downward, the lock plate 45 and the urging spring 46 do not fall off.

Further, as shown in FIG. 20, the operator inserts the first guide shaft 191 and the second guide shaft 192 into the first shaft insertion portion 181 and the second shaft insertion portion 182, respectively, to support the movable unit 180. .. The operator fits the front ends of the first guide shaft 191 and the second guide shaft 192 into the recesses (see FIG. 15) provided in the front housing 13, and inserts an O-ring into the rear end of the front housing 13. The bearing support 15 is fitted while compressing the ring 151.

In this process, the contact portion 453 of the lock plate 45 comes into contact with the protrusion 157 of the bearing support 15. At this point, the urging spring 46 is in an uncompressed state. After that, the bearing support 15 presses the lock plate 45 through the protrusion 157 and moves the urging spring 46 forward along the rib 137 while compressing the urging spring 46. When the bearing support 15 reaches the predetermined position shown in FIG. 21, the assembly of the lock plate 45 is completed. The operator can easily assemble the lock plate 45 to the front housing 13 and the bearing support 15 by such a method.

The method of temporarily fixing the lock plate 45 is not limited to the above method. Although detailed illustration is omitted, for example, the lock plate 45 may be configured to hold the urging spring 46 in a compressed state. Then, the lock plate 45 may be temporarily fixed to the front housing 13 by fixing the front end portion of the urging spring 46 to the locking piece provided on the front housing 13 by press fitting.

Further, for example, the lock plate 45 may be temporarily fixed by using a rubber pin. In this case, a rubber pin holding recess is provided inside the rear end portion of the front housing 13. The holding recess is provided behind the initial position so that the rubber pin comes into contact with the rear end of the lock plate 45. The operator fits the front end portion of the urging spring 46 into the recess 138, and further fits the spring receiving portion 451 of the lock plate 45 into the front end portion of the urging spring 46. After that, the lock plate 45 is temporarily fixed by fitting the rubber pin into the holding recess. Further, when the bearing support 15 is fitted to the predetermined position of the front housing 13, the lock plate 45 is pressed forward from the position where it abuts on the rubber pin and is arranged at the initial position.

Hereinafter, the operation of the hammer drill 101 in this embodiment will be described.

When the trigger 171 is pressed by the user and the switch 172 is turned on, the motor 2 is energized and the drive mechanism 5 is driven. More specifically, as described above, the striking mechanism 6 and / or the rotation transmission mechanism 7 is driven according to the operation mode set via the mode switching dial 800, and the hammer operation and / or the drill operation is performed. Will be done.

In the hammer drill mode and the hammer mode in which the hammer operation is performed, the tip tool 91 is pressed against the work piece, and when the machining work is performed, the striking mechanism 6 drives the tip tool 91 and the striking force of the tip tool 91. Due to the reaction force from the work piece, the striking mechanism 6 mainly generates vibration in the drive axis direction (front-rear direction). Due to this vibration, the movable unit 180 moves in the front-rear direction with respect to the main body housing 10 along the first guide shaft 191 and the second guide shaft 192, and the first urging spring 194 and the second urging spring 195 expand and contract. (Elastic deformation). As a result, the vibration of the movable unit 180 is absorbed, and the vibration transmitted to the main body housing 10 and the handle 17 is reduced.

When the movable unit 180 moves rearward due to vibration and the first urging spring 194 and the second urging spring 195 are compressed by a predetermined amount, the cushioning member 197 held by the bearing support 15 collides with the movable support 18. However, further movement of the movable unit 180 to the rear is restricted. As a result, the collision between the bearing support 15 and the movable support 18 is prevented. Since the cushioning member 197 is made of rubber, the impact due to the collision between the movable support 18 and the cushioning member 197 is reduced due to the elastic deformation of the rubber.

During the machining operation, the user keeps pressing the handle 17 and the main body housing 10 forward toward the workpiece in order to maintain the state in which the tip tool 91 is pressed against the workpiece. Therefore, the movable unit 180 tends to be maintained in a state of being arranged behind the frontmost position shown in FIG. Therefore, in the present embodiment, the cushioning member is not arranged in the shoulder portion 133 for restricting the forward movement of the movable support 18. However, a cushioning member similar to the cushioning member 197 may be arranged in the shoulder portion 133 as well.

Further, as shown in FIG. 9, in the hammer drill mode and the hammer mode, the first transmission member 64 is arranged at the engaging position (position shown by the solid line) and spline-engages with the intervening member 63, and the first intermediate shaft 41 The rotation is transmitted to the intervening member 63. The rotating body 611, which is a part of the movable unit 180, can move with respect to the main body housing 10 within a range between the frontmost position shown by the solid line and the rearmost position shown by the dotted line due to vibration. As described above, the rotating body 611 is spline-engaged with the intervening member 63 held immovably in the front-rear direction. Therefore, the rotating body 611 moves in the front-rear direction with respect to the intervening member 63 along the spline while rotating integrally with the intervening member 63. On the other hand, since the intervening member 63 and the first transmission member 64 do not move relatively in the front-rear direction, the relative movement of the movable unit 180 in the front-rear direction causes the intervening member 63 and the first transmission member 64 to engage with each other. Does not affect. Therefore, the power transmission state from the first intermediate shaft 41 to the motion conversion member 61 (specifically, the rotating body 611) can be stably maintained.

In the hammer drill mode in which the drill operation is performed in addition to the hammer operation, the spindle 31, which is a part of the movable unit 180, also moves in the front-rear direction with respect to the main body housing 10 with vibration. Therefore, as shown in FIG. 10, the driven gear 79 provided on the outer circumference of the cylinder 33 has a position shown by a solid line and a position shown by a dotted line with respect to the drive gear 78 that cannot move in the front-rear direction with respect to the main body housing 10. Can move back and forth between and. On the other hand, in the present embodiment, the length of the drive gear 78 in the front-rear direction is set so as to cover the moving range of the driven gear 79. Therefore, even while the spindle 31 is moving, the driven gear 79 is always meshed with the drive gear 78 and rotated.

Even in the drill mode in which only the drill operation is performed, when the movable unit 180 moves in the front-rear direction with respect to the main body housing 10, the first urging spring 194 and the second urging spring 195 expand and contract as described above. The vibration transmitted to the main body housing 10 and the handle 17 is reduced. Further, as in the hammer drill mode, rotation is transmitted from the second intermediate shaft 42 to the spindle 31 via the drive gear 78 and the driven gear 79 without being affected by the relative movement of the movable unit 180 in the front-rear direction.

In the hammer drill mode and the drill mode in which the drill operation is performed, when a load equal to or higher than the threshold value is applied to the second intermediate shaft 42 during the drill operation, the torque limiter 73 operates as described above to transmit power exclusively for the drill operation. Torque transmission in the path is cut off and the drill operation is stopped.

By the way, in the hammer drill mode and the hammer mode in which the hammer operation is performed, when the tip tool 91 is not attached to the tool holder 32 or when the tip tool 91 is not pressed against the workpiece, that is, no load is applied. In the state (hereinafter referred to as no load state), it is preferable that the striker 67 does not hit the impact bolt 68. Therefore, the hammer drill 101 of the present embodiment is provided with a blank hit prevention mechanism 30 in order to promptly stop the impact bolt 68 from being hit by the striker 67 when the load is not applied. Hereinafter, the blank shot prevention mechanism 30 will be described.

The blank shot prevention mechanism 30 of the present embodiment is a mechanism configured to shift the displacement timing of the impact bolt 68 and capture the striker 67 when the reciprocating movement of the piston 65 is continued in a no-load state. First, the detailed configuration of the striker 67 and the impact bolt 68 will be described.

As shown in FIG. 7, the striker 67 includes a columnar main body portion 671 and a small diameter portion 672 having a diameter smaller than that of the main body portion 671 and projecting forward from the main body portion 671. The main body 671 has a diameter substantially equal to the inner diameter of the piston 65. An O-ring for airtightly sealing between the striker 67 and the piston 65 is mounted on the outer peripheral portion of the main body portion 671. A flange portion 673 is provided at the front end of the small diameter portion 672. The impact bolt 68 is configured as a cylindrical member having a large diameter portion 681 provided at a substantially central portion in the axial direction and small diameter portions 683 and 684 provided on the front side and the rear side of the large diameter portion 681, respectively. ..

On the other hand, as shown in FIG. 22, the blank hit prevention mechanism 30 includes a catcher 34 arranged inside the cylinder 33, a tool holder 32, a regulation ring 35 arranged inside the tool holder 32, and a guide sleeve 36. And a buffer ring 37.

The catcher 34 is configured to capture and hold the striker 67 under no load. The catcher 34 includes a catch ring 341 and a ring holding portion 343. The ring holding portion 343 is a metal tubular member, which is fitted in the front end portion of the cylinder 33 and is held so as to be slidable in the front-rear direction. However, the rearmost position of the catcher 34 is defined by a retaining ring 345 fixed inside the cylinder 33. The capture ring 341 is an O-ring and is mounted in the rear end portion of the ring holding portion 343. The capture ring 341 of this embodiment is made of rubber.

In this embodiment, the tool holder 32 is formed in a stepped cylindrical shape. The inner diameter of the tool holder 32 is the smallest at the front portion having the bit insertion hole 330, and gradually increases toward the rear. In the following, the portion of the tool holder 32 that is connected to the rear side of the front portion and has an inner diameter larger than the diameter of the bit insertion hole 330 is referred to as a small diameter portion 321. A portion connected to the rear side of the small diameter portion 321 and having an inner diameter larger than the inner diameter of the small diameter portion 321 is referred to as a large diameter portion 325. A portion connected to the rear side of the large diameter portion 325 and having an inner diameter larger than the inner diameter of the large diameter portion 325 is referred to as a maximum diameter portion 329. The maximum diameter portion 329 is the rear end portion of the tool holder 32. That is, the cylinder 33 is connected to the rear side of the maximum diameter portion 329.

Inside the tool holder 32, a first shoulder portion 322 is provided at a boundary portion between the small diameter portion 321 and the large diameter portion 325. The rear surface 323 of the first shoulder portion 322 is configured as a conical surface (tapered surface) whose diameter is slightly increased toward the rear. A second shoulder portion 326 is provided at the boundary between the large diameter portion 325 and the maximum diameter portion 329. The rear surface of the second shoulder portion 326 is configured as a plane orthogonal to the drive shaft A1.

The regulation ring 35 is a metal annular member, which is fitted in the maximum diameter portion 329 of the tool holder 32 and is held so as to be slidable in the front-rear direction. The regulation ring 35 comes into contact with the large diameter portion 681 of the impact bolt 68 from the rear, and functions as a regulation portion that restricts further movement of the impact bolt 68 to the rear. Further, the regulation ring 35 is arranged around the small diameter portion 684 of the impact bolt 68, and also functions as a guide portion for guiding the sliding of the small diameter portion 684. Therefore, the regulation ring 35 has an inner diameter substantially equal to that of the small diameter portion 684, and has an inner peripheral surface having a shape consistent with the rear portion of the large diameter portion 681.

In the front-rear direction, a buffer ring 38, which is an annular elastic body, is interposed between the regulation ring 35 and the ring holding portion 343 of the catcher 34. The cushioning ring 38 of the present embodiment is made of rubber and is arranged coaxially with the tool holder 32 between the regulation ring 35 and the ring holding portion 343 in a compressed state. As a result, the regulation ring 35 and the ring holding portion 343 are urged in a direction away from each other, and at all times, each abuts on the frontmost position where the second shoulder portion 326 abuts on the rear surface and the retaining ring 345. It is held in the rearmost position.

The guide sleeve 36 is a metal cylindrical member, and is configured to slidably hold the impact bolt 68 along the drive shaft A1. More specifically, the front half portion of the guide sleeve 36 is arranged around the small diameter portion 683 on the front side of the impact bolt 68, and constitutes the guide portion 360 that guides the sliding of the small diameter portion 683. The guide portion 360 also functions as a regulating portion that comes into contact with the large diameter portion 681 of the impact bolt 68 from the front and restricts further movement of the impact bolt 68 to the front. Therefore, the guide portion 360 has an inner diameter substantially equal to that of the small diameter portion 683, and the inner peripheral surface of the rear end portion of the guide portion 360 has a shape that matches the front portion of the large diameter portion 681. The latter half of the guide sleeve 36 has an inner diameter larger than that of the large diameter portion 681.

Further, the guide sleeve 36 is arranged in the large diameter portion 325 of the tool holder 32 and is held so as to be slidable in the front-rear direction. The outer diameter of the guide sleeve 36 is smaller only at the front end portion than at other portions, and is uniform at other portions. Hereinafter, the front end portion of the guide sleeve 36 is referred to as a small diameter portion 361, and a portion having a substantially uniform outer diameter on the rear side of the small diameter portion 361 is referred to as a large diameter portion 363. The front surface 364 of the large diameter portion 363 is configured as a conical surface (tapered surface) whose diameter is slightly increased toward the rear.

The cushioning ring 37 is an annular elastic body, and defines the front end surface of the guide sleeve 36, that is, the front end surface of the small diameter portion 361, and the tool holder 32 (specifically, the front end of the small diameter portion 321) in the front-rear direction. The surface) is arranged coaxially with the tool holder 32. The outer diameter of the buffer ring 37 is substantially equal to the inner diameter of the small diameter portion 321 of the tool holder 32. The inner diameter of the buffer ring 37 is larger than the outer diameter of the small diameter portion 683 of the impact bolt 68. Therefore, the cushioning ring 37 is held in the small diameter portion 321 in a state of being separated radially outward from the impact bolt 68.

In the present embodiment, an oil seal 39 is arranged in the front end portion of the small diameter portion 321 of the tool holder 32 to prevent the lubricant from leaking from the inside of the spindle 31 and foreign matter from entering the inside of the spindle 31. ing. The front end of the buffer ring 37 is in contact with a washer arranged on the rear side of the oil seal 39. The rear end of the buffer ring 37 is in contact with the guide sleeve 36. However, the front end of the buffer ring 37 may come into direct contact with the inner peripheral surface of the tool holder 32. A washer is arranged on the front side of the guide sleeve 36, and the rear end of the cushioning ring 37 may abut on the washer.

The cushioning ring 37 of the present embodiment is made of rubber and is arranged between the front end surface of the guide sleeve 36 and the washer in a slightly compressed state. As a result, the guide sleeve 36 is urged rearward with respect to the tool holder 32, and the rear end surface of the guide sleeve 36 is always in contact with the front end surface of the regulation ring 35 arranged at the foremost position (hereinafter,). , Called the initial position). At this time, the front surface 364 (conical surface) of the large diameter portion 363 of the guide sleeve 36 is separated rearward from the rear surface 323 (conical surface) of the first shoulder portion 322 of the tool holder 32. That is, there is a gap between the front surface 364 of the large diameter portion 363 and the rear surface 323 of the first shoulder portion 322.

The cross-sectional shape of the buffer ring 37 on the plane including the drive shaft A1 is a substantially octagonal shape that is long in the drive shaft direction (front-rear direction). That is, the buffer ring 37 has a larger dimension (maximum length) in the front-rear direction than a dimension in the wall thickness direction (maximum thickness). Further, the cross-sectional shape of the buffer ring 37 on the plane orthogonal to the drive shaft A1 is not uniform in the front-rear direction. Therefore, as the cushioning ring 37 expands and contracts (elastically deforms) in the front-rear direction, the contact area between the cushioning ring 37 and the guide sleeve 36 changes. More specifically, the buffer ring 37 has a relatively small contact area with the guide sleeve 36 when it begins to be compressed, and the contact area increases as the compression progresses. The buffer ring 37 having such a shape is easily deformed at the stage when it starts to be compressed, and is less likely to be deformed as the compression progresses. Further, as compared with the one having a uniform cross section in the front-rear direction, it is easily deformed in the front-rear direction, and a relatively large amount of deformation in the front-rear direction, that is, a movement amount of the guide sleeve 36 can be secured.

Hereinafter, the operation of the blank shot prevention mechanism 30 will be described.

In a state where the tip tool 91 is pressed against the workpiece and a load is applied (hereinafter referred to as a load state), as shown in FIG. 22, the impact bolt 68 has a large diameter portion 681 regulated by the tip tool 91. It is pushed to a position where it comes into contact with 35 from the front. The rear end of the impact bolt 68 is arranged in the rear end of the ring holding portion 343. When the motor 2 is driven in this state, the striker 67 hits the impact bolt 68 as described above. The impact bolt 68 transmits the kinetic energy of the striker 67 to the tip tool 91 without the large diameter portion 681 colliding with the guide sleeve 36 (guide portion 360), and drives the tip tool 91 linearly. At this time, the buffer ring 38 can alleviate the impact when the impact bolt 68 bounces backward.

When the user releases the pressing against the work piece, the tip tool 91 moves forward from the rearmost position shown in FIG. 22. When the driving of the piston 65 is continued in this state, as shown in FIG. 23, the impact bolt 68 hit by the striker 67 moves forward with respect to the guide sleeve 36, and the large diameter portion 681 moves from the rear. It collides with the guide unit 360. As a result, the guide sleeve 36 moves forward with respect to the tool holder 32 while compressing the buffer ring 37, and the front surface 364 of the large diameter portion 363 collides with the rear surface 323 of the first shoulder portion 322.

The impact bolt 68 can be rebounded by the reaction force from the guide sleeve 36 and hit again by the striker 67 pushed out by the reciprocating motion of the piston 65. However, the impact absorption by the buffer ring 37 and the movement of the guide sleeve 36 with respect to the tool holder 32 disturb the displacement timing (rebound cycle) of the impact bolt 68, so that the striker 67 reciprocates between the two cycles. Displacement occurs. As a result, as shown by the dotted line in FIG. 23, when the small diameter portion 672 of the striker 67 enters the catcher 34, the flange portion 673 is captured by the capture ring 341, and the reciprocating movement of the striker 67 is stopped.

In the blank hit prevention mechanism 30 of the present embodiment, the cushioning ring 37 is arranged between the tool holder 32 and the front end surface of the guide sleeve 36 in the front-rear direction (drive axis direction). As a result, it is possible to suppress an increase in the diameter of the tool holder 32 as compared with a configuration in which an elastic body is arranged between the tool holder 32 and the guide sleeve 36 in the radial direction, and it is possible to prevent a compact blank shot in the radial direction. The mechanism 30 is realized. By adopting such a blank hit prevention mechanism 30, the distance from the drive shaft A1 to the outer surface of the main body housing 10 (specifically, the barrel portion 131), particularly the upper surface (so-called center height) is suppressed, and a narrow space is created. The usable range of the hammer drill 101 at (for example, a corner surrounded by a wall) can be expanded. Further, as described above, the barrel portion 131 is a portion that can be gripped by the user during the processing work. Therefore, by reducing the diameter of the barrel portion 131, it becomes easy for the user to grip the barrel portion 131.

Further, the guide sleeve 36 is urged rearward by the buffer ring 37 and is in contact with the regulation ring 35 arranged on the rear side of the guide sleeve 36. Therefore, the guide sleeve 36 can be stably held between the buffer ring 37 and the regulation ring 35, and the buffer ring 37 elastically deforms at the same time as the guide sleeve 36 moves forward to absorb the impact. it can.

In the blank hit prevention mechanism 30, the configuration of the buffer ring 37 can be changed as appropriate. For example, instead of the buffer ring 37, the buffer ring 371 shown in FIG. 24 or the buffer ring 372 shown in FIGS. 25 and 26 may be adopted. The cushioning ring 371 of FIG. 24 is a cylindrical elastic body, and like the cushioning ring 37, the dimension in the axial direction is larger than the dimension in the wall thickness direction. The outer edges of the front and rear ends of the buffer ring 371 are chamfered. As a result, it is possible to prevent the outer edge from being pinched (bitten) between the washer and the tool holder 32 and between the guide sleeve 36 and the tool holder 32 and damaged. The buffer ring 372 of FIGS. 25 and 26 is a corrugated annular member as a whole, and has irregularities in the front-rear direction. Like the buffer ring 37, the cushioning ring 372 is an elastic body having a larger dimension in the front-rear direction than a dimension in the wall thickness direction and having a non-uniform cross-sectional shape in a plane orthogonal to the drive shaft A1. Therefore, it is easily deformed in the front-back direction.

Further, instead of the single buffer ring 37, for example, as shown in FIG. 27, a plurality of O-rings 373 may be arranged side by side in the front-rear direction. Although two O-rings 373 are illustrated in FIG. 27, three or more O-rings 373 may be arranged depending on the space in the small diameter portion 321. The O-ring 373 is an elastic body having a relatively small amount of deformation in the front-rear direction by itself. On the other hand, by adopting a plurality of O-rings 373, it is possible to increase the amount of deformation of the plurality of O-rings 373 as a whole in the front-rear direction as compared with the case of a single unit. The plurality of O-rings 373 may all have the same configuration, or may have different cross-sectional diameters.

The correspondence between each component of the above embodiment and each component of the present invention is shown below. However, each component of the embodiment is merely an example, and does not limit each component of the present invention. The hammer drill 101 is an example of a “striking tool”. The spindle 31 is an example of a “final output shaft”. The drive shaft A1 is an example of a “drive shaft”. The motor 2 and the motor shaft 25 are examples of a “motor” and a “motor shaft”, respectively. The drive mechanism 5 is an example of a “drive mechanism”. The main body housing 10 is an example of a “housing”. The movable support 18 is an example of a “movable support”. The first urging spring 194 and the second urging spring 195 are examples of "at least one elastic member". The first guide shaft 191 and the second guide shaft 192 are examples of the "first guide shaft" and the "second guide shaft", respectively. The support hole 190 of the bearing 184 of the first shaft insertion portion 181 is an example of the “first hole”. The support hole 190 of the bearing 184 of the second shaft insertion portion 182 is an example of the “second hole”.

The handle 17 is an example of a “handle”. The first intermediate shaft 41 and the second intermediate shaft 42 are examples of the "first intermediate shaft" and the "second intermediate shaft", respectively. The cushioning member 197 is an example of "at least one cushioning member". The first intermediate shaft is an example of an "intermediate shaft". The drive gear 78 and the driven gear 79 are examples of the “drive gear” and the “driven gear”, respectively.

It should be noted that the above embodiment is merely an example, and the striking tool according to the present invention is not limited to the configuration of the exemplified hammer drill 101. For example, the changes illustrated below can be made. It should be noted that only one or a plurality of these modifications can be adopted in combination with the hammer drill 101 shown in the embodiment or the invention described in each claim.

In the above embodiment, as an example of a striking tool, a hammer drill 101 capable of performing a hammer operation and a drill operation is exemplified. However, the striking tool may be an electric hammer capable of performing only a hammer operation.

The hammer drill 101 may be configured to operate on power supplied by a rechargeable battery rather than an external AC power source. In this case, instead of the power cable 179, for example, a battery mounting portion to which the battery can be attached and detached is provided at the lower end portion of the handle 17. Further, the motor 2 may be a DC motor instead of an AC motor, or may be a brushless motor instead of a motor having a brush.

The configurations (shape, constituent members, materials, etc.) of the main body housing 10 and the handle 17 can be changed as appropriate. For example, the main body housing 10 may be formed by connecting half-split bodies divided in the left-right direction instead of the front-rear direction.

Further, the anti-vibration structure provided in the main body housing 10 is not limited to that exemplified in the above embodiment. For example, the number of guide shafts that support the movable unit 180 is not limited to two, and may be three or more. When three or more guide shafts are provided, at least the size of the gap corresponding to the two guide shafts may be different. The position and support structure of the guide shaft, and the configurations (shape, material, etc.) of the movable support 18 and the bearing support 15 can be changed as appropriate. For example, in the above embodiment, the first guide shaft 191 is inserted through a pair of front and rear bearings 184 of the first shaft insertion portion 181 to support the movable support 18 at two points. Similarly, the second guide shaft 192 is inserted into a pair of front and rear bearings 184 of the second shaft insertion portion 182 to support the movable support 18 at two points. However, each of the first guide shaft 191 and the second guide shaft 192 may support the movable support 18 in one place.

Further, the first urging spring 194 and the second urging spring 195 are other types of springs (for example, tension coil springs, torsion springs), or elastic members other than springs (for example, rubber, synthetic resin having elasticity (for example, for example). , Urethane foam). Further, the cushioning member 197 interposed between the movable support 18 (movable unit 180) and the main body housing 10 or the bearing support 15 may be replaced with, for example, rubber. It may be formed of an elastic synthetic resin (for example, a urethane foam) or may be omitted. The number of urging members and cushioning members of the movable support 18 may be 1, or 3 or more. You may.

Arrangement of the first intermediate shaft 41 (rotating shaft A3) and the second intermediate shaft 42 (rotating shaft A4) with respect to the motor shaft 25 (rotating shaft A2), and the first intermediate shaft 41 (rotation) with respect to the spindle 31 (driving shaft A1). The arrangement of the shaft A3) and the second intermediate shaft 42 (rotary shaft A4) is not limited to the arrangement exemplified in the above embodiment. For example, in a plane orthogonal to the drive axis A1, the rotation axis A3 and the rotation axis A4 may be arranged in a straight line with the rotation axis A2 in between. Further, contrary to the above embodiment, the first intermediate shaft 41 and the second intermediate shaft 42 may be arranged on the left side and the right side with respect to the drive shaft A1 (or the reference plane VP), respectively.

Further, the power for the hammer operation and the drill operation may be transmitted from one intermediate shaft to the motion conversion member 61 and the driven gear 79 of the spindle 31. That is, a single intermediate shaft may be shared for power transmission for hammering and drilling operations. In this case, on a single intermediate shaft, a first clutch mechanism 62 for transmitting or disengaging power for hammer operation and a second clutch mechanism for drilling or disengaging power for hammer operation are provided. It may be provided. In this case, as the configuration of the intermediate shaft and the second clutch mechanism 71, for example, the configuration disclosed in Japanese Patent Application Laid-Open No. 2016-000447 can be adopted.

Further, for example, the intervening member 63 is omitted, and the first transmission member 64 of the first clutch mechanism 62 is separated from the position where it engages with the motion conversion member 61 (specifically, the rotating body 611) and the motion conversion member 61. It may be movable to and from the position where it is to be. That is, the first transmission member 64 may be configured to directly transmit the rotation of the first intermediate shaft 41 to the motion conversion member 61. Further, the second clutch mechanism 71 is configured to transmit or cut off power not between the second driven gear 424 and the second intermediate shaft 42 but between the second intermediate shaft 42 and the drive gear 78. May be good.

The hammer drill 101 may have only a hammer drill mode and a hammer mode among the three operation modes of the hammer drill mode, the hammer mode, and the drill mode. In this case, only the second clutch mechanism 71 may be provided on the second intermediate shaft 42, and the first clutch mechanism 62 may be omitted. In this case, the first switching member 81 and the first spring 83 of the mode switching mechanism 80 are also omitted.

The driven side member 75 of the torque limiter 73 and the second intermediate shaft 42 may be spline-engaged, for example, not via the ball 76. The drive-side member 74 may be movable on the second intermediate shaft 42 instead of the driven-side member 75. Further, the torque limiter 73 may be omitted or may be provided on the spindle 31.

In the mode switching mechanism 80, the shape and arrangement of the first switching member 81, the second switching member 82, the first spring 83, and the second spring 84, and the mode of interlocking with the mode switching dial 800 can be appropriately changed. For example, the first switching member 81 for switching the first clutch mechanism 62 and the second switching member 82 for switching the second clutch mechanism 71 are configured to be moved by separate operating members. May be done. Further, the operating member linked to the mode switching mechanism 80 is not limited to the rotary dial, and may be, for example, a slide lever. The first spring 83 and the second spring 84 may be other types of springs (for example, a tension coil spring or a torsion spring), and the first switching member 81 and the second switching member 82 are not necessarily urged. It does not have to be. Further, on the left side where the second intermediate shaft 42 and the rotation transmission mechanism 7 are arranged with respect to the reference surface VP, there is a large empty space as compared with the right side where the first intermediate shaft 41 and the striking mechanism 6 are arranged. Therefore, the mode switching mechanism 80 may be provided on the left side portion of the main body housing 10 by utilizing this space.

The blank shot prevention mechanism 30 may be omitted, or another type of blank shot prevention mechanism may be provided.

Further, in view of the gist of the present invention and the above-described embodiment, the following aspects are constructed. The following aspects may be adopted in combination with the hammer drill 101 shown in the embodiment and the above-mentioned modifications, or the invention described in each claim.
[Aspect 1]
The first guide shaft and the second guide shaft are arranged symmetrically with respect to a plane including the drive shaft and the shaft of the handle.
[Aspect 2]
The drive shaft and the respective shafts of the first guide shaft and the second guide shaft are on the same plane orthogonal to the plane.
[Aspect 3]
The first guide shaft and the second guide shaft are arranged on both sides of a plane including the drive shaft and the shaft of the handle.
The first intermediate shaft and the second intermediate shaft are arranged on both sides of the plane.
[Aspect 4]
The movable support has a third hole arranged coaxially with the first hole and a fourth hole arranged coaxially with the second hole.
The first guide shaft is inserted into the first hole and the third hole.
The second guide shaft is inserted into the second hole and the fourth hole.
[Aspect 5]
Further provided with a partitioning member fixedly attached to the housing and configured to partition the interior of the housing into two regions in the axial direction of the drive shaft.
The final output shaft, the drive mechanism, and the movable support are housed in one of the two regions.
The motor is housed in the other of the two regions.
The partition member supports the first guide shaft and the second guide shaft.
The bearing support 15 is an example of the “partition member” in this embodiment.
[Aspect 6]
The partition member includes a first bearing that rotatably supports the motor shaft, a second bearing that rotatably supports the first intermediate shaft, and a third bearing that rotatably supports the second intermediate shaft. It is configured as a bearing support to support.
The bearing 251 and the bearing 412 and the bearing 422 are examples of the "first bearing", the "second bearing", and the "third bearing" in this embodiment, respectively.

101: Hammer drill, 10: Body housing, 11: Rear housing, 13: Front housing, 131: Barrel part, 133: Shoulder part, 137: Rib, 138: Recess, 15: Bearing support, 151: O ring, 152 : Elastic body, 153: Air bleeding hole, 154: Filter, 155: Projection, 157: Projection, 17: Handle, 171: Trigger, 172: Switch, 179: Power cable, 18: Movable support, 180: Movable unit, 181: 1st shaft insertion part, 182: 2nd shaft insertion part, 183: Cylindrical part, 184: Bearing, 185: Spindle support part, 187: Rotating body support part, 190: Support hole, 191: 1st guide shaft, 192: 2nd guide shaft, 194: 1st urging spring, 195: 2nd urging spring, 197: cushioning member, 2: motor, 20: main body, 25: motor shaft, 251: bearing, 252: bearing, 255: Pinion gear, 27: Fan, 30: Blanking prevention mechanism, 31: Spindle, 316: Bearing, 317: Bearing, 32: Tool holder, 321: Small diameter part, 322: First shoulder part, 323: Rear surface, 325: Large diameter part 326: 2nd shoulder part 329: Maximum diameter part, 33: Cylinder, 330: Bit insertion hole, 34: Catcher, 341: Capture ring, 343: Ring holding part, 345: Stop ring, 35: Regulation Ring, 36: Guide sleeve, 360: Guide part, 361: Small diameter part, 363: Large diameter part, 364: Front, 37, 371, 372: Buffer ring, 373: O ring, 38: Buffer ring, 39: Oil seal , 41: 1st intermediate shaft, 411: bearing, 412: bearing, 414: 1st driven gear, 416: spline part, 417: large diameter part, 42: 2nd intermediate shaft, 421: bearing, 422: bearing, 423 : Gear member, 424: Second driven gear, 425: Spline part, 426: Groove, 45: Lock plate, 451: Spring receiving part, 453: Contact part, 455: Locking part, 46: Bias spring, 5 : Drive mechanism, 6: Strike mechanism, 61: Motion conversion member, 611: Rotating body, 612: Spline part, 614: Bearing, 616: Swing member, 617: Arm part, 62: First clutch mechanism, 63: Interposition Member, 631: Spline part, 64: First transmission member, 641: First spline part, 642: Second spline part, 645: Groove, 65: Piston, 67: Striker, 671: Main body part, 672: Small diameter part, 673: Flange part, 68: Impact bearing, 681: Large diameter part, 683: Small diameter part, 684: Small diameter part, 7: Rotation transmission mechanism, 71: Second clutch mechanism, 72: Second transmission member, 721: First spline part, 722: Second spline part, 725: Groove, 727: Recess, 73: Torque limiter, 74: Drive side member, 742: Cam recess, 743: Spline part, 75: Driven side member, 751: Groove, 752: Cam protrusion, 76: Ball, 77: Bias Spring, 78: Drive gear, 79: Driven gear, 80: Mode switching mechanism, 800: Mode switching dial, 801: Operation unit, 803: 1st pin, 805: 2nd pin, 81: 1st switching member, 813: 1st engaging part, 82: 2nd switching member, 823: 2nd engaging part, 83: 1st spring, 84: 2nd spring, 88: support shaft, 881: stop ring, 91: tip tool, A1: Drive shaft, A2: Rotating shaft, A3: Rotating shaft, A4: Rotating shaft

Claims (9)

It ’s a striking tool,
A final output shaft that is configured to hold the tip tool removable and defines the drive shaft of the tip tool.
A motor with a motor shaft and
A drive mechanism configured to be able to perform at least a hammer operation for linearly driving the tip tool along the drive shaft by the power of the motor.
A housing that houses the motor and the drive mechanism,
In the housing, the final output shaft and at least a part of the drive mechanism are supported, and while being urged by at least one elastic member, the drive shaft moves integrally with the housing in the axial direction. Movable support configured to be possible and
A first guide shaft supported by the housing and extending in the housing in parallel with the drive shaft,
A second guide shaft supported by the housing and extending in parallel with the drive shaft in the housing is provided.
The movable support has a first hole and a second hole that penetrate the movable support in the axial direction.
The first guide shaft and the second guide shaft are inserted into the first hole and the second hole, respectively, and support the movable support so as to be slidable in the axial direction.
The size of the gap between the first guide shaft and the surface defining the first hole is different from the size of the gap between the second guide shaft and the surface defining the second hole. A striking tool featuring. The striking tool according to claim 1.
A striking tool characterized in that the first guide shaft and the second guide shaft are shafts having different diameters from each other. The striking tool according to claim 1 or 2.
A striking tool, wherein a portion of the movable support that defines the first hole and the second hole is made of a material different from the other portions. The striking tool according to any one of claims 1 to 3.
Further provided with a handle that is connected to the housing and extends along an axis that intersects the drive shaft.
A striking tool characterized in that the first guide shaft and the second guide shaft are arranged on both sides of a plane including the drive shaft and the shaft of the handle. The striking tool according to claim 4.
A striking tool characterized in that the drive shaft and the respective shafts of the first guide shaft and the second guide shaft are on the same plane intersecting the plane. The striking tool according to any one of claims 1 to 5.
The drive mechanism is further configured to be capable of performing a drill operation that rotationally drives the tip tool around the drive shaft by the power of the motor.
The striking tool further comprises a first intermediate shaft and a second intermediate shaft, each of which is supported axially immovably with respect to the housing and is configured to rotate as the motor shaft rotates.
The first intermediate shaft is configured to transmit only the hammer operation and the drill operation for performing the hammer operation.
The striking tool is characterized in that the second intermediate shaft is configured to perform only the transmission for performing the drill operation among the hammer operation and the drill operation. The striking tool according to claim 6.
Further provided with a handle that is connected to the housing and projects from the housing along an axis that intersects the drive shaft.
The first intermediate shaft and the second intermediate shaft are arranged on the protruding end side of the handle with respect to the first guide shaft and the second guide shaft in the axial direction of the handle. Striking tool to do. The striking tool according to any one of claims 1 to 7.
Further comprising at least one cushioning member held by one of the housing and the movable support.
The at least one elastic member is at least one spring.
The at least one cushioning member is an elastic body other than the at least one spring, and is arranged so as to abut the other of the housing and the movable support when the at least one spring is deformed by a predetermined amount. A striking tool characterized by that. The striking tool according to any one of claims 1 to 8.
The drive mechanism is further configured to be capable of performing a drill operation that rotationally drives the tip tool around the drive shaft.
The final output shaft is rotatably arranged around the drive shaft.
The drive mechanism is arranged on an intermediate shaft supported by the housing, and is provided on a drive gear configured to rotate around a rotation shaft parallel to the drive shaft by the power of the motor, and a final output shaft. Including a driven gear that is provided and meshes with the drive gear.
On a plane orthogonal to the drive shaft, the angle formed by the straight line passing through the rotation shaft and the drive shaft and the line segment connecting the shaft of the first guide shaft and the drive shaft is the straight line and the straight line. It is smaller than the angle formed by the line segment connecting the shaft of the second guide shaft and the drive shaft.
A striking tool characterized in that the gap with respect to the first guide shaft is smaller than the gap with respect to the second guide shaft.

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