JP7368115B2 - impact tool - Google Patents

Description

The present invention relates to an impact tool configured to drive a tip tool at least linearly.

BACKGROUND ART Impact tools are known that perform machining work (for example, chiseling work) on a workpiece by linearly driving a tip tool along a predetermined drive axis. In such impact tools, relatively large vibrations occur in the axial direction of the drive shaft. Therefore, impact tools are also known that are provided with a dynamic vibration absorber to reduce vibrations. For example, Patent Document 1 discloses a striking tool equipped with a dynamic vibration absorber having a spring member, a weight, and a spring receiver as a sealing member.

Japanese Patent Application Publication No. 2012-35335

In the impact tool disclosed in Patent Document 1, the spring member and the weight of the dynamic vibration absorber are integrally formed in the gear housing, and are inserted and housed in a long housing space that is open at one end. The sealing member compresses the spring member and seals the opening while receiving the biasing force of the spring member. However, since a dynamic vibration absorber requires a certain length, depending on the structure of the gear housing, it may not be possible to secure sufficient accommodation space for the spring member and the weight.

In view of this situation, an object of the present invention is to provide a technique for rationalizing the arrangement of dynamic vibration absorbers in impact tools.

According to one aspect of the invention, a percussion tool is provided that includes a motor, a drive mechanism, a housing, and at least one dynamic vibration reducer. The drive mechanism is configured to linearly drive the tip tool along the drive shaft using the power of the motor. The drive shaft defines the front-rear direction of the impact tool. The housing houses the motor and drive mechanism. Each of the at least one dynamic vibration absorber includes a weight, at least one spring, and a housing. The weight is linearly movable in the front-back direction. At least one spring is located on at least one of the front and rear sides of the weight. The housing accommodates the weight and at least one spring. The drive mechanism includes a crankshaft, a cylinder, and a piston. The crankshaft is configured to be rotated by the power of the motor. The cylindrical cylinder extends in the front-rear direction along the drive shaft. The piston is configured to reciprocate within the cylinder along the drive shaft as the crankshaft rotates. The housing includes a motor housing, a crank housing, and a barrel portion. The motor housing houses the motor. The crank housing houses the crankshaft. The barrel portion is arranged on the front side of the crank housing and houses the cylinder. A portion of the barrel portion and a portion of the crankhousing constitute a first portion and a second portion that are part of the housing portion, respectively.

In the impact tool of this aspect, a portion of the housing portion of the dynamic vibration absorber that accommodates the weight and at least one spring is configured by a portion of the crank housing and a portion of the barrel portion disposed on the front side of the crank housing. be done. Therefore, the dynamic vibration absorber can be arranged rationally without being restricted by the longitudinal length of the crankhousing.

In one aspect of the present invention, the accommodating portion may include a cylindrical member that accommodates at least a portion of the weight and extends in the front-rear direction. The first portion and the second portion may be spaced apart from each other in the front-rear direction and may support the cylindrical member. According to this aspect, it is possible to increase the degree of freedom in setting the length of the housing portion in the front-rear direction (stroke length of the weight).

In one aspect of the present invention, the motor may have a motor shaft rotatable around a rotation axis. The rotating shaft is perpendicular to the drive shaft and defines the vertical direction of the impact tool. The motor housing may be disposed below the crank housing, and the crank housing and the motor housing may be connected and fixed to each other by screws between the first portion and the second portion in the front-rear direction. According to this aspect, before assembling the cylindrical member to the first part and the second part, an operator who assembles the impact tool uses the space between the first part and the second part to attach the crank housing to the motor. It can be easily connected and fixed to the housing.

In one aspect of the invention, the cylindrical member may be held in the housing using the biasing force of at least one spring. According to this aspect, since there is no need to fix the cylindrical member to the housing with screws or the like, the operator can easily assemble and disassemble the housing part.

In one aspect of the present invention, either the first portion or the second portion may be configured as a spring receiving portion that receives the biasing force of at least one spring. According to this aspect, the first part, which is part of the barrel part, or the second part, which is part of the crank housing, is used as a spring receiving part, so that the spring can be efficiently arranged without increasing the number of parts. be able to.

In one aspect of the invention, the at least one dynamic vibration absorber may include two dynamic vibration absorbers arranged symmetrically with respect to a virtual plane including the drive shaft. According to this aspect, the two dynamic vibration absorbers can absorb vibrations in a well-balanced manner on both sides of the virtual plane including the drive shaft.

In one aspect of the present invention, the internal space of the accommodating portion may include a first space formed on the front side of the weight and a second space formed on the rear side of the weight. The first part has a first air passage that communicates the internal space of the barrel part with the first space, and the second part has a second air passage that communicates the internal space of the crankhousing with the second space. It may have. According to this aspect, it is possible to actively vibrate the weight by utilizing pressure fluctuations in the internal space of the barrel portion and the internal space of the crank housing. Thereby, vibrations can be absorbed more effectively.

FIG. 3 is a side view of the entire electric hammer seen from the left side. FIG. 2 is an overall perspective view of an electric hammer. FIG. 7 is a sectional view of the electric hammer when the second housing is in the rearmost position. FIG. 3 is a partial cross-sectional view for explaining the internal structure of the electric hammer. FIG. 7 is a sectional view of the electric hammer when the second housing is in the forwardmost position. FIG. 3 is an overall perspective view of the detection unit. It is an explanatory view of a detection unit when a 2nd housing is in a rearmost position. It is an explanatory view of a detection unit when a 2nd housing is in a forwardmost position. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3 (however, the barrel portion is shown). FIG. 2 is a sectional view taken along line XX in FIG. 1. FIG. FIG. 3 is a rear view of the crank housing and the dynamic vibration reducer. 12 is a sectional view taken along line XII-XII in FIG. 11. FIG. It is an explanatory view of the assembly of a dynamic vibration reducer.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, the electric hammer 1 based on embodiment of this invention is demonstrated. An electric hammer (hereinafter simply referred to as a hammer) 1 is an example of a striking tool configured to linearly drive a tip tool 91 along a predetermined drive axis A1, and is used for chiseling work or scraping work. Ru.

First, a schematic configuration of the hammer 1 will be explained. As shown in FIGS. 1 to 3, the outer shell of the hammer 1 is mainly formed by a housing 20. As shown in FIGS. The housing 20 of this embodiment is configured as a so-called vibration-proof housing, and includes a first housing 21 and a second housing 25 elastically connected to the first housing 21 so as to be movable relative to the first housing 21.

As shown in FIG. 3, the first housing 21 is generally L-shaped in side view. The first housing 21 includes a barrel portion 22, a crank housing 23, and a motor housing 24, which are formed separately and are connected to each other.

The barrel portion 22 is formed in a cylindrical shape and extends along a predetermined drive axis A1. A tool holder 221 to which the tip tool 91 can be attached and detached is disposed within one end of the barrel portion 22 in the axial direction. The crank housing 23 is a hollow body having an internal space, and is connected and fixed to the other end of the barrel portion 22 in the axial direction. A drive mechanism 4 is housed in the barrel portion 22 and the crank housing 23. The motor housing 24 is arranged to intersect with the drive shaft A1 and protrude in a direction away from the drive shaft A1, and is connected and fixed to the crank housing 23. A motor 31 is housed in the motor housing 24 . The rotation axis A2 of the motor shaft 315 is orthogonal to the drive axis A1.

In addition, in the following description, for convenience, the extending direction of the drive shaft A1 of the hammer 1 is defined as the front-back direction of the hammer 1. In the front-rear direction, one end side where the tool holder 221 is provided is defined as the front side (also referred to as the tip region side) of the hammer 1, and the opposite side is defined as the rear side. Further, the extending direction of the rotation axis A2 of the motor shaft 315 is defined as the vertical direction of the hammer 1. In the vertical direction, the direction in which the motor housing 24 protrudes from the crank housing 23 is defined as a downward direction, and the opposite direction is defined as an upward direction. Furthermore, a direction perpendicular to the front-back direction and the up-down direction is defined as the left-right direction.

As shown in FIGS. 1 to 3, the second housing 25 is a hollow body formed in a substantially U-shape as a whole, and includes a grip portion 26, an upper housing 27, and a lower housing 28.

The grip portion 26 is a portion that is configured to be grippable by a user and extends generally in the vertical direction. More specifically, the grip portion 26 is spaced apart rearward from the first housing 21 and extends generally in the vertical direction. A trigger 261 that can be pressed (pulled) by a user's finger is provided at the front of the grip 26 . The upper housing 27 is a part connected to the upper end of the grip part 26. In this embodiment, the upper housing 27 is configured to extend forward from the upper end of the grip portion 26 and cover the barrel portion 22 of the first housing 21 and the crank housing 23 (see FIG. 3). The lower housing 28 is a portion connected to the lower end of the grip portion 26. In this embodiment, the lower housing 28 extends forward from the lower end of the grip portion 26 and is mostly disposed below the motor housing 24 . A battery mounting portion 29 is provided approximately at the center of the lower housing 28 in the front-rear direction. The hammer 1 operates using a battery 93 removably attached to the battery attachment part 29 as a power source.

With the above configuration, in the hammer 1, in addition to the second housing 25, the motor housing 24 of the first housing 21 is exposed to the outside while being sandwiched between the upper housing 27 and the lower housing 28 from above and below. . The second housing 25 and the motor housing 24 form the outer surface of the hammer 1.

The detailed configuration of the hammer 1 will be described below.

First, the vibration-proof housing structure of the housing 20 will be explained. As described above, in the housing 20, the second housing 25 including the grip portion 26 is elastically connected to the first housing 21 so as to be relatively movable. Thereby, vibration transmission from the first housing 21 to the second housing 25 is suppressed.

More specifically, as shown in FIG. 3, an elastic member 501 is interposed between the crank housing 23 of the first housing 21 and the upper housing 27 of the second housing 25. More specifically, the elastic member 501 employs a compression coil spring. Further, a spring receiving portion is provided on the rear wall portion 231 that defines the rear end portion of the crank housing 23. A spring receiving portion facing this spring receiving portion is provided inside the upper housing 27 (specifically, a region adjacent to the upper end of the gripping portion 26). Each of these spring receiving parts is configured as a convex part, and is fitted into the front end and rear end of the elastic member 501 to support the elastic member 501. Further, an annular elastic member (so-called O-ring) 504 is interposed between the barrel portion 22 of the first housing 21 and the front end portion of the upper housing 27.

Further, an elastic member 505 is interposed between the motor housing 24 of the first housing 21 and the lower housing 28 of the second housing 25. More specifically, the elastic member 505 employs a compression coil spring. Further, a portion of the lower end portion of the motor housing 24 is disposed within the lower housing 28 and has a spring receiving portion. A spring receiving portion facing this spring receiving portion is provided inside the lower housing 28. These spring receiving parts are each configured as a recessed part, and support the elastic member 505 by receiving the front end and the rear end of the elastic member 505.

The elastic members 501 and 505 are arranged so that the direction of action of their elastic forces generally coincides with the front-rear direction, and the first housing 21 and the second housing 25 are aligned with each other in the extending direction of the drive shaft A1. The grip portion 26 is urged in the direction away from the first housing 21 (the direction in which the grip portion 26 is moved away from the first housing 21). That is, the first housing 21 and the second housing 25 are urged forward and backward, respectively.

Furthermore, the upper housing 27 and the lower housing 28 are configured to be slidable relative to the upper and lower ends of the motor housing 24, respectively. More specifically, as shown in FIG. 4, the lower end surfaces 511 of the left and right side walls of the upper housing 27 and the upper end surfaces 513 of the left and right side walls of the motor housing 24 are slidable while in contact with each other. It is a moving surface. The lower end surface 511 and the upper end surface 513 constitute the upper sliding part 51. Furthermore, guide rails 521 are provided on the left and right side walls of the lower housing 28, protruding inward (center in the left-right direction) and extending in the front-rear direction. Furthermore, guide grooves 523 extending in the front-rear direction are provided at the lower ends of the left and right side walls of the motor housing 24 . The guide rail 521 is slidably engaged with the guide groove 523 in the front-rear direction. The guide rail 521 and the guide groove 523 constitute the lower sliding part 52. The first housing 21 and the second housing 25 slide in the front-back direction in the upper sliding part 51 and the lower sliding part 52.

Vibration is generated in the first housing 21 by driving the tip tool 91 along the drive shaft A1. Among the vibrations that occur, the largest and predominant one is the vibration in the front-rear direction. In contrast, in the present embodiment, the first housing 21 and the second housing 25 connected via the elastic members 501, 504, and 505 slide on the upper sliding part 51 and the lower sliding part 52. By relatively moving in the front-back direction, it is possible to effectively suppress transmission of the vibration in the front-back direction to the second housing 25 (particularly, the grip portion 26).

Note that the first housing 21 and the second housing 25 are provided with a configuration for defining a relative movable range in the front-rear direction. More specifically, as shown in FIG. 4, a pair of stopper parts 531 that protrude inward are provided on the left and right side walls of the upper end of the lower housing 28. As shown in FIG. Each stopper portion 531 has a recess (not shown). On the other hand, a pair of left and right protrusions 533 that protrude downward are provided at the lower end of the motor housing 24 . The pair of protrusions 533 are arranged within the recesses of the pair of stopper parts 531, respectively. With such a configuration, the first housing 21 and the second housing 25 have two positions: a position where the protrusion 533 contacts the wall surface defining the front end of the recess, and a position where the protrusion 533 contacts the wall surface defining the rear end of the recess. It is possible to move relative to each other in the front and back direction between the two. That is, when the protrusion 533 comes into contact with the wall surface that defines the front end of the recess, the second housing 25 is at the rearmost position with respect to the first housing 21, and when the protrusion 533 comes into contact with the wall surface that defines the rear end of the recess. , it can be said that the second housing 25 is at the forwardmost position with respect to the first housing 21.

As described above, the first housing 21 and the second housing 25 are urged forward and backward by the elastic members 501 and 505, respectively. Therefore, in the initial state, the second housing 25 is held at the rearmost position with respect to the first housing 21. Hereinafter, the rearmost position of the second housing 25 will also be referred to as the initial position. As shown in FIGS. 1 and 3, when the second housing 25 is in the initial position, the position of the upper rear end of the motor housing 24 and the rear end of the crank housing 23 of the upper housing 27 in the front-rear direction The position of the lower rear end of the rear wall portion 271 covering the motor housing 24 generally coincides with the position of the lower front end, and the position of the lower front end of the motor housing 24 generally coincides with the position of the upper front end of the lower housing 28. On the other hand, as shown in FIG. 5, when the second housing 25 is placed at the most forward position with respect to the first housing 21, the motor housing 24 is placed at a position shifted rearward from the upper housing 27 and the lower housing 28. be done.

The detailed configuration and internal structure of the first housing 21 will be described below.

First, the motor housing 24 and its internal structure will be explained. As shown in FIGS. 1 to 3, the motor housing 24 is formed into a bottomed rectangular cylinder with an open upper side. The motor housing 24 accommodates a motor 31, a speed change dial unit 35, and a detection unit 6.

In this embodiment, a brushless DC motor is used as the motor 31. The motor 31 includes a motor main body 310 that includes a stator and a rotor, and a motor shaft 315 that extends from the rotor and rotates integrally with the rotor. The motor shaft 315 extending in the vertical direction is rotatably supported by bearings at its upper and lower ends. A fan 33 is arranged between the motor main body 310 and the upper bearing. The fan 33 is fixed to the motor shaft 315 and rotates integrally with the motor shaft 315. The fan 33 flows into the housing 20 through an intake port 201 (see FIG. 1), flows around the motor 31 to cool the motor 31, and then flows out of the housing 20 through an exhaust port (not shown). is configured to generate an air flow that The upper end of the motor shaft 315 protrudes into the crank housing 23, and a drive gear is formed in this portion. The drive gear meshes with a driven gear of the crankshaft 41.

The speed change dial unit 35 is disposed at the lower end of the motor housing 24 on the rear side of the motor main body 310. The speed change dial unit 35 is a device for receiving a setting input for the rotational speed of the motor 31 according to an external operation by a user. Although detailed illustration is omitted, the speed change dial unit 35 includes a dial as an operating member that can be rotated by the user from outside the motor housing 24. The speed dial unit 35 is connected to the controller 30 by wiring (not shown), and is configured to output to the controller 30 a signal indicating a resistance value (that is, a set rotational speed) according to the rotational position of the dial. ing.

The detection unit 6 is configured to detect the relative position of the second housing 25 in the front-rear direction with respect to the first housing 21 . As shown in FIGS. 4 and 6, in this embodiment, the detection unit 6 includes a lever 61, a Hall sensor 63, and a holder 65. The lever 61 and the Hall sensor 63 are assembled into a holder 65 to constitute the detection unit 6 as a single assembly.

The holder 65 is mainly composed of a base 651 and a lever support part 653. The base 651 is a long plate-shaped portion fixed to the motor housing 24 . The lever support portion 653 is a plate-shaped portion that protrudes rearward from the back surface of the base 651 so as to be orthogonal to the base 651 .

The lever 61 includes a long plate-shaped lever arm 610 and a cylindrical portion 615 protruding from the lever arm 610. A magnet 62 is fixed to one surface of one end of the lever arm 610. The lever 61 is supported by a lever support portion 653 so as to be rotatable around a rotation axis A4 extending in the left-right direction. More specifically, the lever support portion 653 is provided with a support shaft that protrudes rightward from the right side surface. With the cylindrical part 615 of the lever 61 fitted to the support shaft of the lever support part 653, the lever 61 can be rotated to the lever support part 653 by tightening a screw into the female threaded part formed in the support shaft. Supported by Of the two ends of the lever arm 610, the end opposite to the end to which the magnet 62 is fixed is an end that is actuated by the second housing 25 in response to relative movement of the second housing 25. functions as Hereinafter, the end opposite to the end to which the magnet 62 is fixed will be referred to as a first end 611, and the end to which the magnet 62 is fixed will be referred to as a second end 612.

Furthermore, the cylindrical portion 615 is equipped with a torsion coil spring 67 . One end portion of the torsion coil spring 67 is locked to a lever support portion 653. The other end of the torsion coil spring 67 is locked near the first end 611 of the lever arm 610. As a result, the first end 611 of the lever 61 is urged in a direction away from the base 61, and the portion near the second end 612 is held at a position where it abuts against a stopper protrusion 655 provided on the base 651. There is.

The Hall sensor 63 is a well-known sensor including a Hall element, and is mounted on the substrate 631. The substrate 631 is fixed to the lever support part 653 via a screw so that the surface on which the Hall sensor 63 is mounted faces the surface on which the magnet 62 of the lever arm 610 is fixed. The Hall sensor 63 is electrically connected to the controller 30 via wiring (not shown), and outputs a specific signal (on signal) to the controller 30 when the magnet 62 is placed within a predetermined detection range. It is configured as follows.

The detection unit 6 configured as described above is fixed to the first housing 21 by fixing the holder 65 to the motor housing 24 . More specifically, inside the motor housing 24, on the rear side of the motor 31, an internal rear wall portion 243 is provided so as to be orthogonal to the front-rear direction (see FIG. 3). The base 651 is screwed onto the rear surface of the upper end of the internal rear wall 243 with the second end 612 of the two ends of the lever arm 610 being placed on the lower side and the first end 611 being placed on the upper side. (not shown).

As shown in FIG. 7, the first end 611 of the lever arm 610 extends from the opening at the upper end of the motor housing 24 to the inside of the upper housing 27 (the space between the crank housing 23 and the rear wall 271 of the upper housing 27). ) stands out. A contact portion 273 that protrudes forward is provided at the lower end of the rear wall portion 271 . In this embodiment, as shown in FIGS. 3 and 7, when the second housing 25 is at the initial position (rearmost position) with respect to the first housing 21, the lever 61 is moved to the second end as described above. A portion near the portion 612 is held in a position where it abuts against the stopper protrusion 655, and the first end portion 611 of the lever 61 is placed at the rearmost position within its rotatable range. Note that at this time, the first end portion 611 is slightly spaced apart from the contact portion 273 forward. The position of the lever 61 at this time is referred to as the initial position of the lever 61. When the lever 61 is in the initial position, the magnet 62 is on the right side of the Hall sensor 63, facing the Hall sensor 63, and within its detection range. Therefore, the Hall sensor 63 outputs an on signal to the controller 30.

On the other hand, as shown in FIG. 5 and FIG. The lever 61 is pushed forward against the urging force of the lever 67, and the lever 61 rotates counterclockwise (in the direction of the arrow CCW in FIG. 8) from the initial position when viewed from the left side. That is, the lever 61 rotates in conjunction with the relative movement of the second housing 25 forward. When the second housing 25 moves relatively forward from the initial position to a predetermined position, the lever 61 also rotates within a predetermined angular range from the initial position and is placed at the corresponding predetermined position. Accordingly, the magnet 62 leaves the detection range of the Hall sensor 63 and stops outputting the ON signal.

In this embodiment, the distance between the rotation axis A4 of the lever 61 and the second end 612 (specifically, the distance between the magnet 62) is the same as the distance between the rotation axis A4 and the first end 611. The distance is set to be slightly shorter than the distance (specifically, the distance between the first end 611 and the contact position of the contact portion 273). Therefore, the movement (amount of movement) of the second end 612 when the lever 61 rotates from the initial position to the predetermined position in conjunction with the relative forward movement of the second housing 25 is the same as that of the first end 611. is slightly larger than the movement (amount of movement). Thereby, the magnet 62 is reliably removed from the detection range of the Hall sensor 63 in conjunction with the relative movement of the relatively small second housing 25 forward.

Note that the predetermined position (hereinafter referred to as the off position) of the second housing 25 is set slightly rearward than the forwardmost position (the position shown in FIG. 8) in the movable range of the second housing 25. Similarly, the predetermined position of the lever 61 (hereinafter referred to as the OFF position) is set slightly rearward from the position where the first end 611 is located at the forwardmost position of the rotatable range (the position shown in FIG. 8). ing. When the second housing 25 and the lever 61 are between the off position and the forwardmost position, the Hall sensor 63 does not output an on signal.

Although details will be described later, the detection result of the Hall sensor 63 is used for drive control of the motor 31 by the controller 30.

Hereinafter, the crank housing 23, the barrel portion 22, and their internal structures will be described.

As shown in FIGS. 3 and 4, the crank housing 23 is formed as a generally rectangular hollow body. On the other hand, as shown in FIGS. 3 and 9, the barrel portion 22 is formed as an elongated cylindrical body. The crank housing 23 and the barrel portion 22 are connected and fixed to each other in the front-rear direction by screws (not shown), and constitute a drive mechanism accommodating portion that accommodates the drive mechanism 4. Further, as shown in FIGS. 3 and 4, the lower end of the crank housing 23 is disposed within the upper end of the motor housing 24 and is connected and fixed to the motor housing 24 by screws 246. As a result, the first housing 21 is formed as a single housing.

The drive mechanism 4 will be explained. In this embodiment, the drive mechanism 4 is configured to linearly drive the tip tool 91 along the drive shaft A1 (hereinafter referred to as a hammer operation) using the power of the motor 31, as shown in FIG. As shown, it includes a motion conversion mechanism 40 and a striking element 46.

The motion conversion mechanism 40 is a mechanism configured to convert rotational motion of the motor shaft 315 into linear motion of the piston 43. In this embodiment, a well-known crank mechanism including a crankshaft 41, a connecting rod 42, a piston 43, and a cylinder 45 is employed as the motion conversion mechanism 40.

The crankshaft 41 is arranged on the rear side of the motor shaft 315 and extends in the vertical direction. The crankshaft 41 is rotatably supported by two bearings held in the crank housing 23 about a rotation axis A3 parallel to the rotation axis A2 of the motor shaft 315 and orthogonal to the drive axis A1. The crankshaft 41 has a driven gear that meshes with the drive gear of the motor shaft 315, and rotates around the rotation axis A3 as the motor shaft 315 rotates. Further, the crankshaft 41 has an eccentric pin provided at a position eccentric from the rotation axis A3. One end of the connecting rod 42 is connected to an eccentric pin, and the other end is connected to a piston 43 via a connecting pin. The cylinder 45 is an elongated cylindrical body, and is housed in the barrel portion 22 and extends in the front-rear direction along the drive shaft A1. Piston 43 is slidably disposed within cylinder 45 . The piston 43 reciprocates back and forth within the cylinder 45 as the crankshaft 41 rotates.

The striking element 46 is configured to move linearly in the front-rear direction as the piston 43 reciprocates, and applies a striking force to the tip tool 91. In this embodiment, the striking element 46 includes a striker 461 and an impact bolt 463. The striker 461 is disposed within the cylinder 45 so as to be slidable in the front-back direction. An air chamber 465 is formed between the striker 461 and the piston 43 for linearly moving the striker 461 through air pressure fluctuations caused by the reciprocation of the piston 43. The impact bolt 463 is arranged to be slidable in the front-rear direction within the tool holder 221 held within the front end of the barrel portion 22.

When the motor 31 is driven and the piston 43 is moved forward, the air in the air chamber 465 is compressed and the internal pressure increases. Therefore, the striker 461 is pushed forward at high speed by the action of the air spring, collides with the impact bolt 463, and transmits kinetic energy to the tip tool 91 via the impact bolt 463. The tip tool 91 receives the transmitted kinetic energy and is driven linearly along the drive axis A1 to strike the workpiece. On the other hand, when the piston 43 is moved rearward, the air in the air chamber 465 expands, the internal pressure decreases, and the striker 461 is drawn rearward. The tip tool 91 moves backward by being pressed against the workpiece. In this way, the motion conversion mechanism 40 and the striking element 46 repeat the hammering operation, thereby performing chiseling work and cleaning work.

By the way, as described above, when the hammer 1 performs the hammer operation, a relatively large vibration is generated in the first housing 21 in the front-rear direction. Therefore, as shown in FIGS. 4 and 10, in this embodiment, the hammer 1 is provided with a pair of left and right dynamic vibration absorbers 7 for absorbing vibrations generated in the first housing 21. The pair of dynamic vibration absorbers 7 have the same configuration and are oriented toward a virtual plane P (a virtual plane including the drive shaft A1, the rotation axis A2, and the rotation axis A2) that includes the drive shaft A1 and extends in the vertical direction. They are arranged symmetrically. Further, as shown in FIG. 1, the pair of dynamic vibration absorbers 7 are slightly below the drive shaft A1 and extend in the front-rear direction parallel to the drive shaft A1.

The detailed configuration of the dynamic vibration reducer 7 will be described below. As shown in FIG. 10, in this embodiment, each dynamic vibration absorber 7 includes a weight 71, two springs 72 arranged on both sides of the weight 71, and a housing section 73 that houses the weight 71 and the springs 72. It is constituted as a subject.

The weight 71 is formed as a long cylindrical member extending in the front-rear direction. More specifically, the weight 71 has a large diameter portion 711 having a uniform diameter and a small diameter portion 713 having a smaller diameter than the large diameter portion 711 and protruding from the front and rear ends of the large diameter portion 711. The two springs 72 are each fitted into the small diameter portion 713, and one end of each spring 72 is in contact with the end of the large diameter portion 711. In addition, in the following, when the two springs 72 are referred to collectively or when referring to either one without distinction, it is simply referred to as the spring 72, and when referring to the spring 72 arranged on the front side of the weight 71 among the two springs 72, it is referred to as the spring 72. , the front spring 721, and when referring to the spring 72 disposed on the rear side of the weight 71, the spring 72 is referred to as the rear spring 723.

The accommodating portion 73 is formed as a whole into a cylindrical shape with both ends closed, and is formed by connecting a plurality of members. In this embodiment, the accommodating portion 73 is configured using a portion of the barrel portion 22 and a portion of the crank housing 23. More specifically, the housing portion 73 includes a first support portion 74 that is a part of the barrel portion 22, a second support portion 75 that is a part of the crankhousing 23, a sleeve 76, and a cap 77.

As shown in FIGS. 9 and 10, the pair of first support portions 74 of the pair of dynamic vibration absorbers 7 are provided at the lower rear end portions of the barrel portion 22, respectively, so as to protrude left and right. The first support portion 74 is formed into a bottomed cylindrical shape, with the front-rear direction being the axial direction, the front end being closed and the rear end being open. In other words, the first support portion 74 has a recess that opens rearward. The recess is configured as a stepped recess in which the inner diameter of the front portion is smaller than that of the rear portion.

As shown in FIGS. 4 and 10, the pair of second support portions 75 are provided at the lower central portion of the crank housing 23, respectively, so as to protrude left and right. Note that the pair of second support parts 75 are coaxially arranged at positions spaced apart rearward from the pair of first support parts 74. The second support portion 75 is formed into a cylindrical shape whose axial direction is the front-rear direction.

The sleeve 76 is formed as a cylindrical body separate from the first support part 74 and the second support part 75. The sleeve 76 is a member for ensuring stable sliding movement of the weight 71 (specifically, the large diameter portion 711), and has an inner diameter that is approximately the same as the diameter of the large diameter portion 711.

The cap 77 is formed into a bottomed cylindrical shape with a closed rear end and an open front end. The cap 77 is coaxially fitted and connected to the rear end of the sleeve 76 and closes the opening at the rear end of the sleeve 76 . As shown in FIGS. 11 and 12, a protrusion 771 that protrudes radially outward is provided at the rear end of the cap 77. As shown in FIGS.

As shown in FIG. 10, the sleeve 76 and the cap 77 are coaxially supported by the first support part 74 and the second support part 75. More specifically, the front end of the sleeve 76 is inserted into the large diameter portion of the recess of the first support portion 74 . Further, the rear end portion of the sleeve 76 and the front portion of the cap 77 are inserted into the second support portion 75. A rear portion of the cap 77 projects rearward from the second support portion 75. With such a configuration, the housing portion 73 having a cylindrical internal space (accommodation space) is formed. Note that an O-ring 761 is attached to the front end of the sleeve 76 for sealing a gap between the inner peripheral surface of the first support part 74 and the outer peripheral surface of the sleeve 76. Further, at the rear end of the sleeve 76 and the center of the cap 77, an O-ring 762 and 773 is installed.

The weight 71 and the spring 72 are inserted into the internal space of the accommodating portion 73 in a state in which the two springs 72 are compressed and the large diameter portion 711 of the weight 71 is able to slide within the sleeve 76 while receiving the biasing force of the spring 72. It is accommodated. Further, the sleeve 76 and the cap 77 are fixedly held on the crank housing 23 by using the biasing force of the spring 72.

More specifically, a spring receiving member 725 is fitted into the front end of the front spring 721. The spring receiving member 725 is fitted into the small diameter portion of the recess of the first support portion 74 and is in contact with the bottom surface of the recess. The rear end of the rear spring 723 is in contact with the cap 77. In this embodiment, the sleeve 76 and the cap 77 are biased rearward as the two springs 72 are compressed, but the rearward movement is restricted by a stopper pin 772 fixed to the crank housing 23, and the sleeve 76 and the cap 77 are kept at a predetermined position. Retained. Specifically, as shown in FIGS. 11 and 12, the protrusion 771 of the cap 77 is arranged so as to protrude upward, and is abutted and locked by the stopper pin 772 from the front, so that the sleeve 76 and The cap 77 is positioned and held in the front-rear direction. The stopper pins 772 are provided as a pair on the rear side and above the pair of second support parts 75, and protrude leftward and rightward from the left and right side walls of the crank housing 23, respectively. With this configuration, the first support portion 74 receives a forward biasing force from the spring 72 via the spring receiving member 725, and the stopper pin 772 receives a backward biasing force from the spring 72 via the cap 77. There is.

Further, the center portion of the stopper pin 772 is curved and recessed, and the rear end surface of the protrusion 771 has a shape that matches this recess. By engaging the protrusion 771 with the recess of the stopper pin 772, the cap 77 is positioned and held with respect to the crank housing 23 not only in the front-rear direction but also in the circumferential direction around the axis of the accommodating portion 73.

In this embodiment, the dynamic vibration absorber 7 is assembled as follows.

As shown in FIG. 13, the operator first fits and connects the cap 77 fitted with the O-ring 773 into the sleeve 76 fitted with the O-rings 761 and 762. Next, the operator sequentially inserts the rear spring 723, the weight 71, and the front spring 721 into which the spring receiving member 725 is fitted into the connection body of the sleeve 76 and the cap 77. At this time, the front end portion of the front spring 721 including the spring receiving member 725 is in a state of protruding forward from the opening at the front end of the sleeve 76. The operator inserts the connected body of the sleeve 76 and the cap 77 in which the weight 71 and the spring 72 are housed into the second support part 75 from the rear, and then inserts the front end of the front spring 721 and the sleeve 76 into the first support part. 74 from the rear. Note that at this time, the operator adjusts the position of the connecting body in the circumferential direction so that the protrusion 771 does not interfere with the stopper pin 772.

Next, the operator pushes the cap 77 forward while compressing the spring 72 until the protrusion 771 is disposed in front of the stopper pin 772, and then moves to a position where the protrusion 771 engages with the recess of the stopper pin 772. Rotate the cap 77 in the circumferential direction until. When the operator releases the push-in of the cap 77, the protrusion 771 is locked to the stopper pin 772 by the biasing force of the spring 72, and the assembly is completed. Note that a groove 775 is formed in the rear end surface of the cap 77, into which the tip of a flathead screwdriver can be engaged. Therefore, the operator can easily perform a series of operations of pushing in and rotating the cap 77 using a flathead screwdriver.

Note that before the connected body of the sleeve 76 and the cap 77 is inserted into the first support part 74 and the second support part 75, there is a space between the first support part 74 and the second support part 75 in the front-rear direction. Space exists. Therefore, in this embodiment, this space is utilized to connect and fix the crank housing 23 to the motor housing 24 disposed below with screws 246.

More specifically, as shown in FIGS. 4 and 13, a pair of base portions 233 are provided at the lower end of the crank housing 23. The pair of base parts 233 are located between the first support part 74 and the second support part 75 in the front-rear direction and below the first support part 74 and the second support part 75 in the vertical direction, and are located on the left side and protrudes to the right. On the other hand, the motor housing 24 is provided with a pair of left and right base portions 245 that protrude upward. The base portion 233 and the base portion 245 are fixed from above the base portion 233 with screws 246. In this way, by using the space between the first support part 74 and the second support part 75, the operator can easily attach the crank housing 23 and the motor housing 24 with the screws 246 before assembling the dynamic vibration absorber 7. It can be connected and fixed to.

Note that, as shown in FIG. 13, on the rear side of the second support portion 75 (the position where the cap 77 is disposed), the crank housing 23 and the motor housing 24 are connected in the same manner before the dynamic vibration absorber 7 is assembled. , are connected and fixed with screws.

By the way, the dynamic vibration absorber 7 of this embodiment is configured as a dynamic vibration absorber of a type (so-called air vibration type) in which the weight 71 is actively vibrated using pressure fluctuations within the barrel portion 22 and the crank housing 23. has been done. More specifically, as shown in FIG. 10, the internal space of the housing portion 73 includes a front space 731 formed in front of the weight 71 by the weight 71 (specifically, the large diameter portion 711), and a front space 731 formed by the weight 71 (in detail, the large diameter portion 711). It is divided into a rear space 733 formed on the rear side.

As shown in FIG. 9, the front space 731 communicates with the internal space of the barrel portion 22 that accommodates the cylinder 45 (not shown in FIG. 9) via a passage 741. Note that the end of the passage 741 on the front space 731 side communicates with the inside of the small diameter portion of the first support portion 74 (see FIG. 10). As mentioned above, the sleeve 76 is not located at this position. Therefore, the passage 741 is formed as a single through hole extending obliquely upward from the first support part 74 to the barrel part 22.

Further, as shown in FIG. 4, the rear space 733 communicates with the internal space of the crank housing 23 that accommodates the crankshaft 41 via a passage 743. The end of the passage 743 on the rear space 733 side communicates with the inside of the cap 77 . Therefore, the passage 743 is formed by a through hole 744 provided in the cap 77 and a through hole 745 extending upward from the second support portion 75 to the crank housing 23 so as to be continuous with the through hole 744. . Note that the through hole 744 provided in the cap 77 communicates with the through hole 745 by positioning the cap 77 in the circumferential direction by the protrusion 771 and the stopper pin 772 as described above.

When the hammer 1 is driven, the pressure in the internal space of the barrel portion 22 and the internal space of the crank housing 23 fluctuates as the motion conversion mechanism 40 and the striking element 46 are driven, and the pressure fluctuations are approximately 180 degrees. Has a phase difference. That is, when the pressure in the internal space of the barrel portion 22 increases, the pressure in the internal space of the crankhousing 23 decreases, and when the pressure in the internal space of the barrel portion 22 decreases, the pressure in the internal space of the crankhousing 23 increases. There is a relationship of doing so. Therefore, by communicating the front space 731 and the rear space 733 of the dynamic vibration absorber 7 with the internal space of the barrel portion 22 and the internal space of the crank housing 23, respectively, the dynamic vibration absorber By actively driving the weight 71 of No. 7, vibrations can be effectively absorbed. Note that since this air excitation method itself is well known, detailed explanation thereof will be omitted here.

The detailed configuration and internal structure of the second housing 25 will be described below.

First, the upper housing 27 will be explained. As shown in FIGS. 1 to 3, the rear portion of the upper housing 27 is formed in a substantially rectangular box shape with an open bottom, and covers the crank housing 23 from above. Further, the front portion of the upper housing 27 is formed in a cylindrical shape and covers the outer periphery of the barrel portion 22 . An auxiliary handle 97 (see FIGS. 1 and 2) can be attached to and detached from the outer peripheral surface of this cylindrical portion. Note that, since the configuration of the auxiliary handle 97 is well known, detailed description thereof will be omitted here.

The grip portion 26 and its internal structure will be explained. As shown in FIG. 3, the grip portion 26 is configured as a cylindrical portion extending in the vertical direction. A trigger 261 that can be pressed (pulled) by an operator is provided at the front of the grip 26 . A switch 263 is provided inside the grip portion 26 and can be switched between an on state and an off state according to the operation of the trigger 261. The switch 263 is electrically connected to the controller 30 via wiring, and is configured to output a signal indicating an on state or an off state to the controller 30.

The lower housing 28 and its internal structure will be explained. As shown in FIGS. 1 to 4, the lower housing 28 is formed into a rectangular box shape with a partially open upper side. The lower housing 28 extends forward from the lower end of the grip portion 26 and is mostly disposed below the motor housing 24 . Lower housing 28 includes a battery mounting section 29, a battery protection section 280, and a connection section 285.

As described above, the battery mounting portion 29 is provided at the lower end of the substantially central portion of the lower housing 28 in the front-rear direction. In this embodiment, the battery mounting section 29 is configured to be able to attach and detach only one rechargeable battery 93. Note that the battery 93 that is removably attached to the hammer 1 of this embodiment is a battery with a maximum voltage of 40 volts.

Here, the configuration of the battery 93 will be briefly described. For convenience of explanation, the vertical direction of the battery 93 is defined when it is attached to the hammer 1. As shown in FIGS. 3 and 4, the battery 93 is formed into a substantially rectangular parallelepiped shape. The center of gravity G of the battery 93 is approximately at the center position in any of the longitudinal (length) direction, lateral (width) direction, and height direction. The battery 93 has a hook 931, a button 933, a terminal (not shown), and a pair of guide grooves 935.

The hook 931 and the terminal are provided on the top surface of the battery 93. The hook 931 is provided at one end of the battery 93 in the longitudinal direction (direction perpendicular to the paper plane of FIG. 3, left-right direction in FIG. 4), and is normally biased by a spring (not shown) and protrudes upward from the top surface. There is. The button 933 is provided at the upper end of the side surface of the battery 93 that defines the lateral direction. The hook 931 is configured to retract downward from the top surface in response to a downward pressing operation of the button 933. The terminal is provided on the top surface of the battery 93 adjacent to the hook 931. The pair of guide grooves 935 are formed as grooves extending linearly in the longitudinal direction at the upper ends of a pair of side surfaces arranged along the longitudinal direction of the battery 93 .

As shown in FIGS. 1 to 4, in response to the battery 93 having such a configuration, the battery mounting part 29 is configured such that the upper end of the battery 93 is mounted with a part of the battery 93 exposed on the lower side. is configured to be In this embodiment, the battery mounting part 29 is configured to be able to slide and engage the battery 93 in the left-right direction, with the longitudinal direction of the battery 93 being in the same direction as the left-right direction. Specifically, the battery mounting portion 29 includes a pair of guide rails 293, a hook engaging portion 291, and a battery connection terminal (not shown). The pair of guide rails 293 extend linearly in the left-right direction and are configured to be slidably engaged with the pair of guide grooves 935 of the battery 93. The hook engaging portion 291 is a concave portion recessed upward, and is configured to be able to engage the hook 931 of the battery 93. The battery connection terminal is configured to be electrically connected to the terminal of the battery 93 when the guide groove 935 is slidably engaged with the guide rail 293 and the hook 931 is engaged with the hook engaging portion 291. .

In this embodiment, the battery 93 is mounted on the battery mounting portion 29 by being slid from the left side of the hammer 1 toward the right side with the hook 931 disposed on the left side. Therefore, the hook engaging portion 291 is arranged at the left end of the battery mounting portion 29, and the battery connecting terminal is configured to be connected to the terminal of the battery 93 from the right side. A button 933 for releasing the engagement of the hook 931 is provided at the upper end of the left side. For this reason, a recess 287 is provided in a portion of the lower housing 28 adjacent to the upper side of the button 933. The recess 287 is configured such that the user can insert his or her finger therein, thereby facilitating the user's operation of the button 933.

Furthermore, when the battery 93 is attached to the battery mounting portion 29, the center of gravity G of the battery 93 is aligned with the rotation axis A2 of the motor shaft 315 and the rotation axis of the crankshaft 41 in the front-rear direction (as seen from the left or right side). A3 (see FIG. 3). Further, the battery mounting portion 29 is configured such that when the battery 93 is mounted, the center of gravity G of the battery 93 is approximately on the center line of the housing 20 (the above-mentioned virtual plane P) in the left-right direction (as seen from the front side or the rear side). (See FIG. 4).

The battery protection unit 280 and its internal configuration will be described below.

The battery protection unit 280 is configured to protect the exposed portion of the battery 93 from external force when the battery 93 is attached to the battery attachment unit 29. In this embodiment, the battery protection section 280 includes a front protection section 281 and a rear protection section 282 provided on both sides of the battery mounting section 29 in the front-rear direction. In this embodiment, the front protection part 281 and the rear protection part 282 are each formed as a part of the housing 20 (lower housing 28). More specifically, the front protection part 281 and the rear protection part 282 are each formed as a hollow part of the lower housing 28 that protrudes below the battery mounting part 29 with the battery mounting part 29 therebetween. .

As shown in FIGS. 3 and 4, in the vertical direction, the lower surfaces of the front protection section 281 and the rear protection section 282 respectively protrude below the lower surface of the battery 93 attached to the battery attachment section 29. is configured to do so. Furthermore, in the left-right direction, the front protection section 281 and the rear protection section 282 are slightly shorter than the battery 93. Therefore, when the battery 93 is attached to the battery attachment portion 29, the left and right end portions of the battery 93 slightly protrude from the lower housing 28 in the left-right direction.

In this embodiment, the upper end of the battery 93 is attached to the battery attachment part 29, and most of the battery 93 is exposed below the battery attachment part 29. Therefore, the front protection section 281 and the rear protection section 282 are provided to protect the exposed portion of the battery 93 from the battery mounting section 29. Specifically, the front protection section 281 is configured to protect the front side portion of the battery 93 from external force. On the other hand, the rear protection section 282 is configured to protect the rear side portion of the battery 93 from external force. More specifically, the front side protection part 281 protects the front side part by mainly interfering with external force directed toward the front side part from the front side (including diagonally) from the front side protection part 281. The rear side protection part 282 protects the rear side part by mainly interfering with external force directed toward the rear side part from behind (including diagonally) than the rear side protection part 282.

Furthermore, since the battery 93 is formed in a substantially rectangular parallelepiped shape, there are four corner regions 930 at the lower end (two on the left and right sides of the front side and two on the left and right sides of the rear side). These four corner areas 930 are particularly susceptible to external forces when the hammer 1 falls. Therefore, the front protection part 281 and the rear protection part 282 are configured to effectively protect the corner area 930 from impact particularly when dropped. Specifically, a virtual straight line connects the center of gravity of the hammer 1 (including the auxiliary handle 97) when the battery 93 is attached to the battery attachment part 29 and any corner area 930 of the lower front end of the battery 93. and further defines a virtual plane that is perpendicular to the virtual straight line and passes through the corner region 930, the front protection part 281 is formed to protrude further away from the center of gravity than this virtual plane. has been done. Further, the rear protection portion 282 is arranged from a virtual plane that is perpendicular to a virtual straight line connecting the center of gravity of the hammer 1 and any corner region 930 of the lower front end of the battery 93 and that passes through the corner region 930. It stands out.

Generally, the battery 93 is attached and the center of gravity of the hammer 1 is placed on the corner area 930 (in other words, the center of gravity is located directly above the corner area 930 or If the hammer 1 falls and the corner area 930 hits the ground or floor under the full weight of the hammer 1), the impact on the corner area 930 will be greater and the possibility of damage to the battery 93 will increase. . On the other hand, by forming the front side protection part 281 and the rear side protection part 282 so as to protrude beyond the above-mentioned virtual plane, the hammer 1 Even if the corner area 930 falls, the front protection part 281 or the rear protection part 282 contacts the ground or floor first, so the corner area 930 can be effectively protected.

In this embodiment, the controller 30 is housed inside the rear protection section 282. Although detailed illustrations are omitted, the controller 30 includes a control circuit 300 that controls driving of the motor 31, a board on which the control circuit 300 is mounted, and a case that accommodates these. The controller 30 is generally formed into a substantially rectangular parallelepiped shape having length, width, and thickness. Note that among the length, width, and thickness, the length is the maximum and the thickness is the minimum. The controller 30 is disposed within the rear protection portion 282 so that its length, width, and thickness directions coincide with the left-right direction, up-down direction, and front-back direction, respectively. Note that in this embodiment, the control circuit 300 is configured as a microcomputer including a CPU, ROM, RAM, timer, and the like. The controller 30 is electrically connected to the motor 31, the switch 263, the detection unit 6, the terminals of the battery mounting section 29, etc. through wiring 301 (only a portion is shown). The drive control of the motor 31 by the controller 30 will be described in detail later.

The connecting portion 285 and its internal structure will be described below.

As shown in FIGS. 1 to 3, the connecting part 285 is a hollow part that connects the lower end of the grip part 26 and the rear protection part 282, and connects the lower end of the grip part 26 to the rear protection part 282. It extends towards the front. A continuous internal space is formed inside the grip portion 26 and the lower housing 28 . The internal space of the grip part 26 and the internal space of the rear protection part 282 are connected through the internal space of the connecting part 285. Therefore, in the present embodiment, the internal space of the connecting portion 285 is effectively utilized to electrically connect the switch 263 disposed within the grip portion 26 and the controller 30 disposed within the rear protection portion 282. Wiring (not shown), wiring connectors (not shown), and the like are arranged.

Furthermore, a wireless communication unit 286 is housed inside the connection section 285. The wireless communication unit 286 is an electronic device configured to be capable of wireless communication with external devices. In this embodiment, the wireless communication unit 286 sends a predetermined interlocking signal using radio waves in a predetermined frequency band to a stationary dust collector (not shown) that is separate from the hammer 1 according to a control signal from the controller 30. Configured to transmit wirelessly. Since such a system itself is publicly known, to briefly explain, the controller 30 causes the wireless communication unit 286 to transmit an interlocking signal while the trigger 261 is pressed and the switch 263 is in the on state. . The dust collector controller is configured to drive the dust collector motor while receiving the interlock signal transmitted from the wireless communication unit 286. In other words, the user of the hammer 1 can operate the dust collector in conjunction with the hammer 1 simply by pressing the trigger 261.

In this way, in this embodiment, the convenience of the hammer 1 is improved by effectively utilizing the internal space of the connecting portion 285, which tends to be a vacant space, and arranging the wireless communication unit 286. Note that the wireless communication unit 286 is not limited to one that transmits interlocking signals to the dust collector, and may be configured to perform wireless communication with other external devices (for example, a mobile terminal), or may be omitted. Good too.

Furthermore, air intake ports 201 are formed in the left and right side walls of the connecting portion 285 to communicate the inside and outside of the connecting portion 285 . As the motor 31 is driven, the airflow generated by the fan 33 flows into the connection part 285 from the intake port 201, passes through the lower housing 28, and flows into the motor housing 24. In this embodiment, the controller 30 is disposed near the intake port 201 and on the airflow path. Therefore, not only the motor 31 but also the controller 30 are effectively cooled by the airflow generated by the fan 33.

The drive control of the motor 31 by the controller 30 will be described below.

In this embodiment, the controller 30 (more specifically, the control circuit 300) is configured to perform so-called soft no-load control. Soft no-load control means that when the switch 263 is in the on state, the rotational speed of the motor 31 is set to a predetermined relatively low rotational speed (hereinafter referred to as an initial This is a drive control method that limits the rotational speed of the motor 31 to a value below (referred to as the rotational speed), but allows the rotational speed of the motor 31 to exceed the initial rotational speed in a loaded state. According to the soft no-load control, unnecessary power consumption of the motor 31 in a no-load state can be reduced. In this embodiment, the rotational speed set by the speed change dial unit 35 is used as the rotational speed corresponding to the maximum operation amount of the trigger 261 (that is, the maximum rotational speed). The rotational speed of the motor 31 is set based on the maximum rotational speed and the actual operation amount (operation ratio) of the trigger 261.

In this embodiment, the detection result of the detection unit 6 is used to distinguish between a no-load state and a load state in soft no-load control. As described above, the Hall sensor 63 of the detection unit 6 detects, via the magnet 62, the position of the lever 61 that is linked to the relative movement of the second housing 25 with respect to the first housing 21, thereby detecting the position of the lever 61 relative to the first housing 21. The relative position of the second housing 25 is detected.

In the no-load state, the second housing 25 is placed at the rearmost position (initial position) due to the urging force of the elastic members 501 and 505, and the lever 61 is also placed at the initial position (see FIGS. 3 and 7). . Therefore, the Hall sensor 63 detects the magnet 62, and the detection unit 6 outputs an on signal. The controller 30 determines that the motor 31 is in a no-load state when the output from the detection unit 6 is on. The controller 30 starts driving the motor 31 when the switch 263 is turned on from the off state. At this time, if the rotation speed calculated based on the maximum rotation speed and the operation amount of the trigger 261 is equal to or lower than the initial rotation speed, the calculated rotation speed is directly set as the rotation speed of the motor 31. On the other hand, if the calculated rotational speed exceeds the initial rotational speed, the initial rotational speed is set as the rotational speed of the motor 31. As the motor 31 is driven, the drive mechanism 4 is driven and a hammer operation is performed.

When the user presses the tip tool 91 against the workpiece while gripping the gripping part 26, the second housing 25 is moved against the second housing 25 at the upper sliding part 51 and the lower sliding part 52. It slides and moves forward from the initial position while compressing the elastic members 501 and 505. In conjunction with the relative forward movement of the second housing 25, the lever 61 also rotates from its initial position. When the second housing 25 and the lever 61 reach the off position, the Hall sensor 63 stops outputting the on signal. The controller 30 recognizes the change in the output from the Hall sensor 63 from on to off as a transition from a no-load state to a loaded state.

When the controller 30 recognizes the transition to the load state, it drives the motor 31 at a rotation speed calculated based on the maximum rotation speed and the amount of operation of the trigger 261. At this time, when the controller 30 increases the rotational speed of the motor 31 to the calculated rotational speed, the controller 30 may immediately increase the rotational speed to the calculated rotational speed or may gradually increase the rotational speed. The controller 30 stops driving the motor 31 when the trigger 261 is released and the switch 263 is turned off. Note that when the switch 263 is turned on while the output from the Hall sensor 63 is off (that is, under load), the controller 30 calculates the rotation speed based on the maximum rotation speed and the operation amount of the trigger 261. Driving of the motor 31 is started at the rotation speed.

The controller 30 stops driving the motor 31 when the trigger 261 is released and the switch 263 is turned off.

Note that, when the switch 263 is in the on state, the controller 30 changes the output from the Hall sensor 63 from off to on (that is, the relative movement of the second housing 25 and lever 61 from the off position to the initial position, from the loaded state). If a shift to a no-load state is recognized, the rotational speed of the motor 31 may be limited to an initial rotational speed or less. In this case, for example, the controller 30 uses a timer to monitor the duration of the ON state of the Hall sensor 63 after the change. Then, the rotational speed of the motor 31 may be limited to the initial rotational speed or less only when the on state continues for a predetermined period of time. This is to reliably distinguish between a temporary change to the on state when the first housing 21 is vibrating due to machining work and a change from a loaded state to an unloaded state.

Specifically, the second housing 25 reciprocates in the front-rear direction with respect to the first housing 21 due to the vibration of the first housing 21 in the front-rear direction. In conjunction with this, the lever 61 having the magnet 62 also rotates. In this case, the output from the Hall sensor 63 may switch between on and off in short cycles. On the other hand, when the pressing of the tip tool 91 is released and the state shifts to a no-load state, after the output from the Hall sensor 63 is switched from off to on, the on state continues for a predetermined period of time. Therefore, by adopting the above-described control, the controller 30 can more reliably recognize the transition from the loaded state to the no-load state based on the detection result of the Hall sensor 63.

As described above, the hammer 1 of the present embodiment includes the first housing 21 that houses the motor 31 and the drive mechanism 4, and the grip part 26, and is movable relative to the first housing 21 at least in the front-back direction. A second housing 25 is elastically connected to the second housing 25. The hammer 1 also includes a detection unit 6 configured to detect the pressing of the tip tool 91 against the workpiece, and a configuration configured to control the drive of the motor 31 based on the detection result by the detection unit 6. A controller 30 (specifically, a control circuit 300) is provided. The detection unit 6 is provided with a lever 61 that is provided on the first housing 21 and is configured to be interlocked with the relative movement of the second housing 25 in the front-rear direction, and a lever 61 that is provided on the first housing 21 and configured to interlock with the relative movement of the second housing 25 in the front-rear direction. A Hall sensor 63 configured to detect pressing of the tip tool 91 through the hole sensor 63 is included.

When the tip tool 91 is pressed against the workpiece, the second housing 25 elastically connected to the first housing 21 moves forward relative to the first housing 21. In other words, the transition from the no-load state to the loaded state corresponds to a relative movement of the second housing 25 forward. The relative movement of the second housing 25 in the front-rear direction corresponds to the movement of the lever 61. Therefore, the Hall sensor 63 detects whether or not the tip tool 91 is pressed against the workpiece through the movement of the lever 61 (specifically, whether or not the magnet 62 attached to the second end 612 of the lever 61 is detected). (transition from load state to load state) can be appropriately detected. Based on the detection result by the detection unit 6, the controller 30 can control the drive of the motor 31 depending on whether the tip tool 91 is in a no-load state or a loaded state.

In this embodiment, both the lever 61 of the detection unit 6 and the Hall sensor 63 are provided in the same first housing 21. When the lever 61 is provided on one of the first housing 21 and the second housing 25 and the Hall sensor 63 is provided on the other, the lever 61 may be The positional relationship between the motor and the Hall sensor 63 may be different from the original setting, and the Hall sensor 63 may not be able to accurately detect the transition from the no-load state to the load state. On the other hand, by arranging both the lever 61 and the Hall sensor 63 in the same first housing 21 as in the present embodiment, the positional relationship between the lever 61 and the Hall sensor 63 can be more stabilized, and false detection can be avoided. The possibility can be reduced.

In this embodiment, the detection unit 6 is configured as one assembly including a lever 61 and a Hall sensor 63. Therefore, in the process of assembling the hammer 1, the operator can assemble the previously assembled detection unit 6, which is a single assembly, into the first housing 21, which improves assembly efficiency.

Further, the Hall sensor 63 can detect the movement of the lever 61 without contact by detecting the magnet 62 attached to the lever 61. Therefore, the Hall sensor 63 does not wear out due to contact with the object to be detected, and a decrease in detection accuracy due to wear can be prevented.

Further, in this embodiment, the interlocking member that is interlocked with the relative movement of the second housing 25 in the front-rear direction has a first end 611 and a second end 612, and the first end 611 is lower than the second end 612. A lever 61 that is rotatably supported around a rotation axis A4 located near the portion 611 is employed. In this case, by appropriately setting the shape and size of the rotary lever 61, the position of the rotation axis A4, etc., the arrangement position of the Hall sensor 63 can be changed compared to the case where an interlocking member that moves linearly is adopted. You can increase your degree of freedom. Further, by setting the rotation axis A4 closer to the first end 611 operated by the second housing 25 than the second end 612 used for detecting the movement of the lever 61, the second end The movement of 612 can be increased over the movement of first end 611. Therefore, the relatively small relative movement of the second housing 25 allows the magnet 62 to be reliably removed from the detection range of the Hall sensor 63.

Furthermore, in this embodiment, the first housing 21 and the second housing 25 are elastically connected to be slidable in the front-rear direction. Thereby, the relative movement of the first housing 21 and the second housing 25 in the front-rear direction and the accompanying movement of the lever 61 are more stabilized, and the pressing of the tip tool 91 can be detected with higher accuracy. In particular, in the present embodiment, the first housing 21 and the second housing 25 include two sliding parts (an upper sliding part 51 and a lower sliding part 52) that are spaced apart from each other in the vertical direction. There is. That is, the first housing 21 and the second housing 25 are slidable at two positions, upper and lower. Of the upper sliding section 51 and the lower sliding section 52, the detection unit 6 is provided near the upper sliding section 51, which is closer to the drive shaft A1. In the hammer 1, since the tip tool 91 is arranged along the drive axis A1, the relative forward movement of the second housing 25 due to the pressing of the tip tool 91 against the workpiece is directed toward a position closer to the drive axis A1. is easy to detect accurately. In this embodiment, the sliding movement of the first housing 21 and the second housing 25 in the front-rear direction is further stabilized by the two sliding parts, and the tip tool 91 can be detected with higher accuracy.

Further, in the present embodiment, the controller 30 (control circuit 300) sets the predetermined rotational speed (initial rotational speed ) is configured to drive the motor 31 at a rotational speed not exceeding ). The controller 30 (control circuit 300) further controls the motor at a rotation speed exceeding the initial rotation speed when the Hall sensor 63 detects pressing of the tip tool 91 (when the output of the Hall sensor 63 changes from on to off). 31 can be driven. This makes it possible to save power in a no-load state where the tip tool 91 is not pressed against the workpiece.

Further, the hammer 1 of this embodiment includes a first housing 21 that accommodates a motor 31 and a drive mechanism 4, and two dynamic vibration absorbers 7. The drive mechanism 4 is configured as a crank mechanism including a crankshaft 41, a piston 43, and a cylinder 45. The first housing 21 includes a motor housing 24 that accommodates the motor 31, a crank housing 23 that accommodates the crankshaft 41, and a cylindrical barrel portion 22 that is disposed on the front side of the crank housing 23 and accommodates the cylinder 45. . Each dynamic vibration absorber 7 includes a weight 71 , two springs 72 arranged on the front side and the rear side of the weight 71 , and a housing section 73 that houses the weight 71 and the spring 72 . The first support part 74 and the second support part 75, which are part of the housing part 73, are respectively constituted by a part of the barrel part 22 and a part of the crank housing 23.

Therefore, for example, even if the length of the crank housing 23 in the front-rear direction is less than the length required for the dynamic vibration reducer 7, the dynamic vibration absorber 7 can be placed while using the barrel portion 22 and a part of the crank housing 23. can do. In other words, the dynamic vibration reducer 7 can be arranged rationally without being constrained by the length of the crank housing 23 in the front-rear direction.

Furthermore, in this embodiment, the housing portion 73 of the dynamic vibration absorber 7 includes a cylindrical sleeve 76 that houses at least a portion of the weight 71 and extends in the front-rear direction. The first support portion 74 and the second support portion 75 are spaced apart from each other in the front-rear direction and support the sleeve 76. With such a configuration, for example, by appropriately changing the distance between the first support part 74 and the second support part 75 and the length of the sleeve 76, the length of the housing part 73 in the front-rear direction (the stroke of the weight 71) can be adjusted. long) can be set. Therefore, the degree of freedom in setting the length of the accommodating portion 73 can be increased.

Further, in this embodiment, the sleeve 76 is held by the first housing 21 (specifically, the crank housing 23) using the biasing force of the spring 72. Therefore, since it is not necessary to fix the sleeve 76 to the first housing 21 with screws or the like, the operator can easily assemble and disassemble the housing section 73.

Furthermore, in this embodiment, the first support section 74 is configured as a spring receiving section that receives the forward biasing force of the spring 72. More specifically, the first support part 74 is formed into a bottomed cylindrical shape with a closed front end, and receives the front end of the spring 72 (front spring 721) while holding the spring 72 (front spring 721) inserted therein. With such a configuration, the springs 72 can be efficiently arranged without increasing the number of parts.

Furthermore, in this embodiment, the two dynamic vibration absorbers 7 are arranged symmetrically with respect to a virtual plane P that includes the drive axis A1. Therefore, the two dynamic vibration absorbers 7 can absorb vibrations in a well-balanced manner on both sides of the virtual plane P.

Further, in the present embodiment, the internal space of the housing portion 73 includes a front space 731 formed on the front side of the weight 71 and a rear space 733 formed on the rear side of the weight. The first support part 74 has a passage 741 that communicates the internal space of the barrel part 22 with the front space 731, and the second support part 75 communicates the internal space of the crank housing 23 with the rear space 733. It has a passage 743 that allows According to such a configuration, the weight can be actively vibrated by utilizing pressure fluctuations in the internal space of the barrel portion 22 and the internal space of the crank housing 23. Thereby, vibrations can be absorbed more effectively.

Further, the hammer 1 of the present embodiment includes a housing 20 that accommodates the motor 31 and the drive mechanism 4, and a battery mounting portion 29 that is provided in the housing 20 and is capable of attaching and detaching one battery 93 having a substantially rectangular parallelepiped shape. There is. The drive mechanism 4 is configured as a crank mechanism including a crankshaft 41. The crankshaft 41 is disposed on the rear side of the motor shaft 315 and is rotatable around a rotation axis A3 parallel to the rotation axis A2 of the motor shaft 315. The battery mounting section 29 is arranged below the motor 31. Further, the battery mounting portion 29 allows the battery 93 to be mounted in the left-right direction, and when the battery 93 is mounted, the center of gravity G of the battery 93 is aligned with the rotation axis in the front-rear direction (that is, when viewed from the right or left side). It is configured to be located between A2 and the rotation axis A3.

According to such a battery mounting portion 29, the housing 20 can be made more compact in the front-rear direction compared to a case where a plurality of batteries are mounted in line in the front-rear direction. In addition, in this embodiment, the battery mounting part 29 is further configured so that the battery 93 can be mounted in such a direction that the longitudinal direction of the battery 93 coincides with the left-right direction. Therefore, the housing 20 can be made more compact in the front-rear direction than when one battery is installed with its longitudinal direction aligned with the front-rear direction. Further, the battery mounting section 29 is configured such that the center of gravity of the battery 93 when mounted in the battery mounting section 29 is located near the respective centers of gravity of the motor 31 and the crankshaft 41, which are relatively heavy. . By concentrating the center of gravity in this manner, it is possible to prevent the center of gravity of the battery 93 from moving away from the center of gravity of the hammer 1, and the hammer 1 with excellent workability is realized.

Further, in this embodiment, the hammer 1 includes a front protection part 281 and a rear protection part 282, which are provided on the front side and the rear side of the battery mounting part 29, respectively, in the front-rear direction. The front protection section 281 and the rear protection section 282 are configured to protect the front side portion and the rear side portion of the battery 93 from external forces, respectively. The exposed portion of the battery 93 mounted on the battery mounting portion 29 is a location that is easily damaged when external force is applied. On the other hand, by providing the front protection section 281 and the rear protection section 282, the possibility that the battery 93 is damaged can be reduced. Furthermore, in this embodiment, the front protection part 281 and the rear protection part 282 are configured to protect the corner regions 930 of the lower front end and the lower rear end, respectively, from external forces. Therefore, it is also possible to effectively reduce the possibility of damage to the corner region 930, especially due to impact when dropped. In addition, since the front side protection part 281 and the back side protection part 282 are formed by a part of the housing 20, the protection function of the battery 93 can be added to the hammer 1 without increasing the number of parts.

Further, in this embodiment, a controller 30 including a control circuit 300 configured to control driving of the motor 31 is disposed inside the rear protection section 282. Further, the controller 30 has a substantially rectangular parallelepiped shape having length, width, and thickness. Note that among the length, width, and thickness, the length is the maximum and the thickness is the minimum. The controller 30 is arranged such that the thickness direction matches the front-back direction and the length direction matches the left-right direction. In this way, the controller 30 effectively utilizes the internal space of the rear protection part 282, which tends to be a vacant space, and suppresses the elongation of the rear protection part 282 in the front-rear direction and the vertical direction. 282.

Further, the hammer 1 has a cylindrical grip section 26 that can be gripped by the user and extends in the vertical direction, and connects the lower end of the grip section 26 and the rear end of the rear protection section 282. It further includes a hollow connecting portion 285. Therefore, the internal space of the connection part, which tends to be a vacant space, can be effectively utilized as a space for arranging various parts, wiring, connectors, etc., for example.

The correspondence between each component of the above embodiment and each component of the present invention is shown below. The electric hammer 1 is an example of a "impact tool." The motor 31 is an example of a "motor". The drive mechanism 4 is an example of a "drive mechanism." The tip tool 91 is an example of a "tip tool." The drive shaft A1 is an example of a "drive shaft." The first housing 21 is an example of a "housing". The dynamic vibration absorber 7, the weight 71, the spring 72, and the housing part 73 are examples of a "dynamic vibration absorber", a "weight", a "spring", and a "housing part", respectively. The crankshaft 41, cylinder 45, and piston 43 are examples of a "crankshaft," a "cylinder," and a "piston," respectively. The motor housing 24, the crank housing 23, and the barrel part 22 are examples of a "motor housing", a "crank housing", and a "barrel part", respectively. The first support portion 74 and the second support portion 75 are examples of a “first portion” and a “second portion”, respectively. The connected body of the sleeve 76 and the cap 77 is an example of a "cylindrical member." The motor shaft 315 and the rotating shaft A2 are examples of a "motor shaft" and a "rotating shaft", respectively. The screw 246 is an example of a "screw." The front space 731 and the rear space 733 are examples of a "first space" and a "second space", respectively. Passages 741 and 743 are examples of a "first air passage" and a "second air passage", respectively.

In addition, the said embodiment is a mere illustration, and the impact tool based on this invention is not limited to the structure of the illustrated hammer 1. For example, changes exemplified below can be made. Note that any one or a plurality of these modifications may be employed in combination with the hammer 1 shown in the embodiment or the invention described in each claim.

In the embodiment described above, as an example of the impact tool, the hammer 1 configured to perform only the hammer operation of linearly driving the tip tool 91 is illustrated. However, the present invention may be embodied in other impact tools capable of performing operations other than hammering operations. For example, the impact tool may be a hammer drill that is capable of performing not only a hammer operation but also a drilling operation that rotates the tip tool 91 around the drive shaft A1.

Further, the configuration and arrangement relationship of the motor 31, the drive mechanism 4, the first housing 21 and the second housing 25 that house the motor 31 and the drive mechanism 4 may be changed as appropriate depending on the impact tool. Examples of changes that can be adopted for these are listed below.

The motor 31 may be a motor with brushes instead of a brushless motor. Furthermore, the motor 31 may be an AC motor. In this case, the housing 20 is provided with a power cable connectable to an external commercial power source instead of the battery mounting section 29, and the battery protection section 280 is omitted.

The shapes of the first housing 21 and the second housing 25 may be changed as appropriate. For example, in the above embodiment, the second housing 25 that is elastically connected to the first housing 21 has a structure that partially covers the first housing 21, but the second housing 25 covers the part of the first housing 21 and its parts. The scope is not limited to the illustrative embodiments. The arrangement position, type, and number of the elastic members 501 and 505 interposed between the first housing 21 and the second housing 25 can also be arbitrarily selected. Note that as the elastic members 501 and 505, in addition to compression coil springs, various springs, rubber, and synthetic resins having elasticity can be used.

Further, a handle including the grip portion 26 may be elastically connected to the first housing 21 . In this case, each of the upper and lower ends of the handle may be connected to the first housing 21 via one or more elastic members, or only the upper end of the handle may be cantilevered to the first housing 21. It may also be elastically connected. Further, the upper end of the handle is elastically connected to the main body housing so as to be relatively movable in the front-back direction, while the lower end of the handle is rotatable around a rotation axis extending in the left-right direction. may be supported. The elastic members interposed between the first housing 21 and the handle are similar to the elastic members 501 and 505. Note that the second housing 25 or the handle does not necessarily need to be elastically connected to the first housing 21.

The portion (sliding portion) where the first housing 21 and the second housing 25 slide in the front-rear direction is not limited to the upper sliding portion 51 and the lower sliding portion 52. For example, the sliding portion may be provided at only one location in the vertical direction. Furthermore, the plurality of sliding parts may be provided at different positions from those exemplified in the above embodiments. Alternatively, the sliding portion may be omitted.

The battery mounting part 29 may be modified so that a plurality of batteries 93 can be attached and detached. In this case, the position of the battery mounting section 29 and the configuration of the battery protection section 280 are changed as appropriate. Furthermore, the battery protection unit 280 may be omitted.

In the embodiment described above, for soft no-load control of the motor 31, the detection unit 6 is provided to detect the pressing of the tip tool 91 against the workpiece through the movement of the lever 61. However, instead of the detection unit 6, a detection mechanism (for example, an acceleration sensor) that detects the pressing of the tip tool 91 using another method may be employed. Furthermore, control may be performed such that the motor 31 is not driven while the pressing of the tip tool 91 is not detected, and the driving of the motor 31 is started in response to the detection of the pressing of the tip tool 91. Alternatively, the detection unit 6 and other detection mechanisms may not be provided. That is, there is no need to control the drive of the motor 31 depending on whether or not the tip tool 91 is pressed.

Furthermore, the configuration, arrangement position, and number of dynamic vibration absorbers 7 may be changed as appropriate. Examples of changes that can be made to the dynamic vibration reducer 7 will be given below.

Only one dynamic vibration absorber 7 may be provided. In this case, for example, the dynamic vibration absorber 7 can be provided above the barrel portion 22 and the crank housing 23.

In the above embodiment, the two springs 72 are arranged on both sides of the weight 71, but one end of one spring 72 may be fixed to the accommodating part 73 and the other end may be fixed to the weight 71. Note that the type of spring 72 is not limited to a compression coil spring, and for example, a tension coil spring may be employed.

The sleeve 76 and cap 77 of the housing portion 73 may be configured as a single member or may be omitted. If these are omitted, the first support part 74 and the second support part 75 contact or engage with each other as the barrel part 22 and the crank housing 23 are connected in the front-rear direction. It is sufficient if the configuration is as follows. Further, instead of the first support part 74, the second support part 75 may be configured as a cylindrical spring receiving part with a bottom. Alternatively, both the first support portion 74 and the second support portion 75 may be configured in a cylindrical shape with a bottom.

Further, in the embodiment described above, the coupling body of the sleeve 76 and the cap 77 is retained by the stopper pin 772 using the biasing force of the spring 72 and held by the first housing 21 . However, the cap 77 may be fixed to the first housing 21 with a screw or the like.

Furthermore, in the embodiment described above, the dynamic vibration reducer 7 is configured as an air vibration type dynamic vibration absorber, and the weight 71 actively applies vibration by utilizing pressure fluctuations within the barrel portion 22 and the crank housing 23. be done. However, the dynamic vibration absorber 7 may be a normal dynamic vibration absorber that does not actively vibrate the weight 71.

Furthermore, in view of the spirit of the present invention and the above embodiments, the following aspects are constructed. The following aspects may be employed in combination with the hammer 1 shown in the embodiment and the above-described modifications, or the invention described in each claim.
[Aspect 1]
The crank housing and the barrel portion are constructed separately from each other and are connected and fixed.
[Aspect 2]
The at least one spring includes a first spring located on the front side of the weight and a second spring located on the rear side of the weight.
The front spring 721 and the rear spring 723 are examples of the "first spring" and "second spring" of this embodiment, respectively.
[Aspect 3]
The first portion and the second portion are each configured as a cylindrical portion having an axis extending in the front-rear direction.
[Aspect 4]
In aspect 3, one of the first portion and the second portion configured as the spring receiving portion has a cylindrical shape with a bottom.
[Aspect 5]
In aspect 4, the other of the first portion and the second portion is formed in a cylindrical shape,
The cylindrical member is inserted into and supported by the other of the first portion and the second portion.
[Aspect 6]
A front end or a rear end of the cylindrical member is biased by the at least one spring and is held in contact with a stopper provided on the housing.
The stopper pin 722 is an example of the "stopper part" of this aspect.
[Aspect 7]
The cylindrical member includes a cylindrical sleeve with open front and rear ends, and a cap that closes the opening at the front or rear end of the sleeve.
Sleeve 76 and cap 77 are examples of a "sleeve" and a "cap" in this embodiment.
[Aspect 8]
The impact tool is a hammer configured to perform only an operation of linearly driving the tip tool along the drive shaft.

1: Electric hammer, 20: Housing, 201: Intake port, 21: First housing, 22: Barrel part, 221: Tool holder, 23: Crank housing, 231: Rear wall part, 233: Base part, 24: Motor housing , 243: Internal rear wall, 245: Base, 246: Screw, 25: Second housing, 26: Grip, 261: Trigger, 263: Switch, 27: Upper housing, 271: Rear wall, 273: Contact part, 28: Lower housing, 280: Battery protection part, 281: Front protection part, 282: Rear protection part, 285: Connection part, 286: Wireless communication unit, 287: Recessed part, 29: Battery mounting part, 291 : Hook engaging part, 293: Guide rail, 30: Controller, 300: Control circuit, 301: Wiring, 31: Motor, 310: Motor main body, 315: Motor shaft, 33: Fan, 35: Speed dial unit, 4 : Drive mechanism, 40: Motion conversion mechanism, 41: Crankshaft, 42: Connecting rod, 43: Piston, 45: Cylinder, 46: Impact element, 461: Striker, 463: Impact bolt, 465: Air chamber, 5: Upper side Sliding part, 501: Elastic member, 504: Elastic member, 505: Elastic member, 51: Upper sliding part, 511: Lower end surface, 513: Upper end surface, 52: Lower sliding part, 521: Guide rail, 523 : guide groove, 531: stopper part, 533: protrusion, 6: detection unit, 61: lever, 610: lever arm, 611: first end part, 612: second end part, 615: cylindrical part, 62: magnet, 63: Hall sensor, 631: Substrate, 65: Holder, 651: Base, 653: Lever support part, 655: Stopper protrusion, 67: Coil spring, 7: Dynamic vibration absorber, 71: Weight, 711: Large diameter part, 713: Small diameter part, 72: Spring, 721: Front spring, 723: Rear spring, 725: Spring receiving member, 73: Accommodating part, 731: Front space, 733: Rear space, 74: First support part, 741: Passage , 743: Passage, 744: Through hole, 745: Through hole, 75: Second support part, 76: Sleeve, 761: O ring, 762: O ring, 77: Cap, 771: Projection, 772: Stopper pin, 773 : O-ring, 775: Groove, 81: Tip tool, 91: Tip tool, 93: Battery, 930: Corner area, 931: Hook, 933: Button, 935: Guide groove, 97: Auxiliary handle, A1: Drive shaft , A2: Rotation axis, A3: Rotation axis, A4: Rotation axis

Claims (8)

A striking tool,
motor and
a drive mechanism configured to linearly drive the tip tool along a drive shaft that defines a front-rear direction of the impact tool using the power of the motor;
a housing that accommodates the motor and the drive mechanism;
At least a weight that is linearly movable in the front-rear direction, at least one spring disposed on at least one of the front side and the rear side of the weight, and a housing section that houses the weight and the at least one spring. Equipped with one dynamic vibration absorber,
The drive mechanism is
a crankshaft configured to be rotated by the power of the motor;
a cylindrical cylinder extending in the front-rear direction along the drive shaft;
a piston configured to reciprocate within the cylinder along the drive shaft as the crankshaft rotates;
The housing includes:
a motor housing that houses the motor;
a crank housing that accommodates the crankshaft;
an elongated cylindrical barrel portion disposed on the front side of the crank housing and accommodating the cylinder;
The accommodating portion includes a cylindrical member that accommodates at least a portion of the weight and extends in the front-rear direction, and a first portion that is spaced apart from each other in the front-rear direction and supports the cylindrical member. a second part;
The first part is a cylindrical part formed by a part of the barrel part and having an axis extending in the front-rear direction, and supports the cylindrical member coaxially,
The second part is a cylindrical part formed by a part of the crank housing and has an axis extending in the front-rear direction, and supports the cylindrical member coaxially. tool. The impact tool according to claim 1,
The cylindrical member has a bottomed cylindrical shape with an open front end and a closed rear end,
The first portion has a bottomed cylindrical shape with the front end closed and the rear end open,
The second portion has a cylindrical shape with open front and rear ends,
A front end portion of the cylindrical member is supported while being inserted into the first portion from the rear,
The impact tool is characterized in that a portion of the cylindrical member rearward of the front end portion is supported while being inserted into the second portion. The impact tool according to claim 1 or 2 ,
The motor has a motor shaft that is perpendicular to the drive shaft and rotatable around a rotation axis that defines a vertical direction of the impact tool,
The motor housing is disposed below the crank housing with a lower end of the crank housing disposed within an upper end of the motor housing ,
A base portion provided at the lower end portion of the crank housing and a base portion provided within the upper end portion of the motor housing are connected by a screw between the first portion and the second portion in the front-rear direction. A striking tool characterized by being connected and fixed to each other. The impact tool according to any one of claims 1 to 3 ,
The impact tool is characterized in that the cylindrical member is held by the housing using the biasing force of the at least one spring. The impact tool according to any one of claims 1 to 4,
The impact tool, wherein either one of the first portion and the second portion is configured as a spring receiving portion that receives the biasing force of the at least one spring. A striking tool according to claim 4 depending on claim 2,
The at least one spring includes a front spring disposed on the front side of the weight and a rear spring disposed on the rear side of the weight,
the first portion receives the front end of the front spring;
The impact tool is characterized in that the cylindrical member receives a rear end of the rear spring. The impact tool according to any one of claims 1 to 6 ,
A striking tool, wherein the at least one dynamic vibration absorber includes two dynamic vibration absorbers arranged symmetrically with respect to a virtual plane including the drive shaft. The impact tool according to any one of claims 1 to 7 ,
The internal space of the storage portion includes a first space formed on the front side of the weight, and a second space formed on the rear side of the weight,
The first portion has a first air passage that communicates the internal space of the barrel portion and the first space,
The impact tool is characterized in that the second portion has a second air passage that communicates the internal space of the crank housing with the second space.

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