JP6981803B2 - Strike tool - Google Patents

Description

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

There is known a striking tool that performs machining work on a workpiece by driving the tip tool linearly along a predetermined striking axis. Generally, such striking tools are equipped with various precision instruments for controlling the operation of the striking tools. For example, the striking tool disclosed in Patent Document 1 is equipped with a controller for controlling a drive motor.

Japanese Unexamined Patent Publication No. 2011-131364

In the above-mentioned striking tool, the controller is housed in a rear cover fixed to the motor housing. However, in a striking tool in which relatively large vibration is generated when the tip tool is driven, appropriate protection from vibration is desired for precision equipment such as a controller.

An object of the present invention is to provide a technique that contributes to rational protection from vibration of a mounted precision instrument in a striking tool that drives a tip tool linearly along a predetermined striking axis.

According to one aspect of the present invention, there is provided a striking tool configured to drive the tip tool linearly. This striking tool includes a motor, a drive mechanism, and a vibration sensor.

The drive mechanism is configured to perform a striking operation in which the tip tool is linearly driven along a striking axis extending in the front-rear direction of the striking tool by the power of a motor. The vibration sensor is configured to detect vibration. Further, the vibration sensor is in a state where it is possible to detect the vibration of the first frequency caused by the striking motion among the vibrations generated in the striking tool, and the state in which the transmission of the vibration of the second frequency different from the first frequency is suppressed. It is arranged in.

In general, it is preferable that the precision instrument provided in the striking tool is arranged in a state where the transmission of vibration is suppressed as much as possible in order to reduce the possibility of malfunction. However, with regard to the vibration sensor, if the transmission of vibration is uniformly suppressed, there is a high possibility that an appropriate detection result cannot be obtained. On the other hand, in the striking tool of this embodiment, the vibration sensor detects the vibration of the first frequency caused by the striking motion, which is a characteristic vibration of the striking tool, and the vibration of the second frequency different from this is detected. The vibration sensor can be protected. That is, according to this aspect, it is possible to realize rational protection of the vibration sensor, which is an example of the precision equipment mounted on the striking tool. The "first frequency" and the "second frequency" referred to here may be frequency bands having a certain width.

According to one aspect of the invention, the motor may be configured as a brushless motor having a stator, a rotor, and a motor shaft extending from the rotor. The vibration of the second frequency is vibration caused by the electromagnetic vibration of the motor, and the second frequency may be a frequency defined according to the number of poles formed in the rotor. In a brushless motor, the rotation of a rotor having a magnetic force generates electromagnetic vibration having a frequency corresponding to the number of poles of the rotor, which is transmitted to other parts. The vibration caused by this electromagnetic vibration is a relatively large vibration other than the vibration caused by the striking motion, but according to this embodiment, the vibration sensor can be appropriately protected from this vibration.

According to one aspect of the present invention, the motor may be arranged so that the rotation axis of the motor shaft extends in a direction intersecting the striking axis. Then, at least a part of the vibration sensor may be arranged within the length of the motor shaft with respect to the extending direction of the rotating shaft. According to this aspect, the motor is arranged so that the rotation axis of the motor shaft extends in the direction intersecting the striking axis with respect to the drive mechanism for driving the tip tool along the striking axis extending in the front-rear direction. In the striking tool, it is possible to easily detect the vibration caused by the striking motion and realize a rational arrangement of the vibration sensor.

According to one aspect of the present invention, the vibration sensor may be arranged behind the motor in the front-rear direction. In the case of a striking tool in which the motor is arranged so that the rotation axis of the motor shaft extends in the direction intersecting the striking axis, the drive mechanism that drives the tip tool along the striking axis extending in the front-rear direction is used. Space is likely to be created behind the motor compared to the direction. In this aspect, the vibration sensor can be arranged by effectively utilizing this space.

According to one aspect of the invention, the striking tool may further include a first housing that houses the motor and drive mechanism. The vibration sensor may be held in the first housing via at least one elastic body. According to this aspect, the vibration sensor is held by the elastic body with respect to the first housing accommodating the motor and the drive mechanism as the vibration source, and the vibration of the first frequency caused by the striking motion is caused. Can protect the vibration sensor from vibrations of the second frequency while detecting.

According to one aspect of the present invention, at least one elastic body may include a first elastic body and a second elastic body. The vibration sensor may be held in the first housing in a state of being sandwiched between the first elastic body and the second elastic body in the front-rear direction. According to this aspect, the transmission of the vibration of the second frequency from the first housing to the vibration sensor is effectively suppressed by the first elastic body and the second elastic body arranged in the front-rear direction with the vibration sensor in between. Can be done.

According to one aspect of the present invention, the first elastic body and the second elastic body may be integrally connected via a connecting portion. When the vibration sensor is placed in the first housing with the first elastic body and the second elastic body sandwiched in the front-rear direction, one of the first elastic body and the second elastic body is hidden by the vibration sensor and is assembled. There is a possibility that it cannot be visually confirmed whether or not it is present. On the other hand, according to this aspect, when one of the first elastic body and the second elastic body is forgotten to be assembled, the assembling worker can immediately and visually recognize the forgotten assembly. Further, it is possible to reduce the possibility of losing the first elastic body and the second elastic body, which tend to be small parts.

According to one aspect of the present invention, the striking tool may further include a gripping portion that extends in the vertical direction orthogonal to the striking axis and is configured to be gripped by the user. The at least one elastic body may include a pair of elastic bodies each engaged with the left and right ends of the vibration sensor in the left-right direction orthogonal to the front-back direction and the up-down direction. According to this aspect, the transmission of vibration of the second frequency from the first housing to the vibration sensor can be effectively suppressed by the pair of elastic bodies engaged with the left and right ends of the vibration sensor.

According to one aspect of the present invention, each of the pair of elastic bodies may have a pair of inclined surfaces that incline so as to approach each other in the vertical direction as they move away from the vibration sensor in the left-right direction. Then, each of the pair of elastic bodies may be engaged with the first housing via the pair of inclined surfaces. According to this aspect, it is possible to effectively suppress the transmission of vibration in a direction different from the vibration caused by the striking motion from the first housing to the vibration sensor.

According to one aspect of the present invention, the striking tool may further include a grip portion configured to be gripped by the user. The grip portion may be connected to the first housing via an elastic body so as to be relatively movable. According to this aspect, it is possible to effectively suppress the vibration of the first housing from being transmitted to the grip portion gripped by the user.

According to one aspect of the present invention, the striking tool controls the drive of the motor based on the detection result of the vibration sensor and the second housing connected via the elastic body so as to be relatively movable with respect to the first housing. Further, a controller configured as described above may be provided. Then, the controller may be housed in the second housing. The controller, like the vibration sensor, is a precision instrument. According to this aspect, since the controller is housed in the second housing in which the vibration transmission from the first housing is suppressed, the controller can be appropriately protected from the vibration. The second housing may include a grip portion.

It is a vertical sectional view of the hammer drill which concerns on 1st Embodiment. It is a cross-sectional view of a motor. It is explanatory drawing which shows the internal structure of the hammer drill with a part of the housing removed from the rear view. FIG. 3 is a cross-sectional view taken along the line IV-IV of FIG. It is explanatory drawing which shows the whole structure of the elastic intervening member. It is a vertical sectional view of the hammer drill which concerns on 2nd Embodiment. FIG. 6 is a perspective view of a cross section taken along line VII-VII of FIG. It is an exploded perspective view for demonstrating a holding member, an elastic intervening member, and an elastic ring. It is a perspective view of the holding member in a stacked state. It is a perspective view of the cross section of the lower end part of a motor accommodating part. It is a perspective view of the vertical cross section of the lower end part of a motor accommodating part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, a hammer drill will be illustrated as an example of a striking tool.

[First Embodiment]
Hereinafter, the hammer drill 1 according to the first embodiment will be described with reference to FIGS. 1 to 5. The hammer drill 1 of the present embodiment has an operation of linearly driving the tip tool 91 mounted on the tool holder 34 along a predetermined drive shaft A1 (hereinafter referred to as a striking operation) and a tip tool 91 around the drive shaft A1. It is configured to be able to execute an operation that is driven to rotate (hereinafter referred to as a drill operation).

First, a schematic configuration of the hammer drill 1 will be described with reference to FIG. As shown in FIG. 1, the outer shell of the hammer drill 1 is mainly formed by the housing 10. The housing 10 of the present embodiment is configured as a so-called anti-vibration housing, and includes a first housing 11 and a second housing 13 elastically connected to the first housing 11 so as to be elastically connected to the first housing 11.

The first housing 11 includes a motor accommodating portion 111 accommodating the motor 2 and a drive mechanism accommodating portion 117 accommodating the drive mechanism 3, and is formed in a substantially L shape as a whole. The drive mechanism accommodating portion 117 is formed in a long shape extending in the drive shaft A1 direction. A tool holder 34 is provided at one end of the drive mechanism accommodating portion 117 in the drive shaft A1 direction so that the tip tool 91 can be attached and detached. The tool holder 34 is rotatably held in the first housing 11 around the drive shaft A1, and the tip tool 91 is held so as to be non-rotatable and movably linearly movable in the drive shaft A1 direction. It is configured. The motor accommodating portion 111 is connected and fixed so as not to be relatively movable with respect to the drive mechanism accommodating portion 117 at the other end portion of the drive mechanism accommodating portion 117 in the drive shaft A1 direction, intersects the drive shaft A1, and crosses the drive shaft. It is arranged so as to protrude in the direction away from A1. In the motor accommodating portion 111, the motor 2 is arranged so as to extend in a direction in which the rotation shaft A2 of the motor shaft 25 intersects the drive shaft A1 (specifically, in a direction orthogonal to each other).

In the following description, for convenience, the drive shaft A1 direction of the hammer drill 1 is defined as the front-rear direction of the hammer drill 1, and one end side on which the tool holder 34 is provided is the front side (also referred to as the tip region side) of the hammer drill 1. The opposite side is defined as the rear side. Further, the extending direction of the rotating shaft A2 of the motor shaft 25 is defined as the vertical direction of the hammer drill 1, the direction in which the motor accommodating portion 111 protrudes from the drive mechanism accommodating portion 117 is defined as the downward direction, and the opposite direction is defined as the upward direction. Further, the direction orthogonal to the front-rear direction and the left-right direction is defined as the left-right direction.

The second housing 13 includes a grip portion 131, an upper portion 133, and a lower portion 137, and is formed in a substantially U shape as a whole. The grip portion 131 is a portion that is configured to be grippable by an operator and is arranged so as to extend in the rotation axis A2 direction (that is, the vertical direction) of the motor shaft 25. More specifically, the grip portion 131 extends in the vertical direction so as to be separated rearward from the first housing 11. A trigger 14 that allows the user to perform a pressing operation (pulling operation) with a finger is provided on the front portion of the grip portion 131. The upper portion 133 is a portion connected to the upper end portion of the grip portion 131. In the present embodiment, the upper portion 133 extends forward from the upper end portion of the grip portion 131 and is configured to cover most of the drive mechanism accommodating portion 117 of the first housing 11. The lower portion 137 is a portion connected to the lower end portion of the grip portion 131. In the present embodiment, the lower portion 137 extends forward from the lower end portion of the grip portion 131 and is arranged below the motor accommodating portion 111. A battery mounting portion 15 is provided at the lower end portion of the central portion of the lower portion 137 in the front-rear direction. The hammer drill 1 operates by the electric power supplied from the battery 93 mounted on the battery mounting portion 15.

With the above configuration, in the hammer drill 1, in addition to the second housing 13, the motor accommodating portion 111 of the first housing 11 is exposed to the outside in a state of being sandwiched between the upper portion 133 and the lower portion 137 from above and below. It forms the outer surface of the hammer drill 1.

Hereinafter, the detailed configuration of the hammer drill 1 will be described. First, with reference to FIG. 1, the vibration-proof housing structure of the housing 10 will be briefly described. As described above, in the housing 10, the second housing 13 including the grip portion 131 is elastically connected to the first housing 11 accommodating the motor 2 and the drive mechanism 3 so as to be relatively movable. Vibration transmission from 11 to the second housing 13 (particularly, the grip portion 131) is suppressed.

More specifically, as shown in FIG. 1, a pair of left and right first springs 71 are arranged between the drive mechanism accommodating portion 117 of the first housing 11 and the upper portion 133 of the second housing 13. .. Further, a second spring 75 is arranged between the motor accommodating portion 111 of the first housing 11 and the lower portion 137 of the second housing 13. In the present embodiment, the first spring 71 and the second spring 75 are composed of compression coil springs, and the grip portion 131 holds the first housing 11 and the second housing 13 in the drive shaft A1 direction. It is urging away from. In addition to these springs, an O-ring 77 formed of an elastic member is arranged in an intervening manner between the front end portion of the drive mechanism accommodating portion 117 and the cylindrical front side portion of the upper portion 133.

Further, the upper portion 133 and the lower portion 137 are configured to be slidable with respect to the upper end portion and the lower end portion of the motor accommodating portion 111, respectively. More specifically, the lower surface of the upper surface portion 133 and the upper end surface of the motor accommodating portion 111 are formed as sliding surfaces that can slide in the drive shaft A1 direction in a state of being in contact with each other, and the upper sliding portion 81 is formed. Configure. Further, the upper surface of the lower portion 137 and the lower end surface of the motor accommodating portion 111 are formed as sliding surfaces that can slide in the drive shaft A1 direction in a state of being in contact with each other, and constitute the lower sliding portion 82. do. The upper sliding portion 81 and the lower sliding portion 82 function as sliding guides that guide the first housing 11 and the second housing 13 so as to move relative to each other in the drive shaft A1 direction. As a result, it is possible to effectively suppress the transmission of the largest and dominant vibration in the drive shaft A1 direction to the grip portion 131 among the vibrations generated when the striking motion is performed.

Hereinafter, the detailed configuration of the first housing 11 and its internal structure will be described with reference to FIGS. 1 to 3.

First, the motor accommodating portion 111 and its internal structure will be described. As shown in FIG. 1, the motor accommodating portion 111 is formed in the shape of a bottomed rectangular cylinder with an open upper side. In the present embodiment, the motor 2 is accommodated in the motor accommodating portion 111. In this embodiment, a brushless motor including a stator 21, a rotor 22, and a motor shaft 25 extending from the rotor 22 is adopted as the motor 2 because of its small size and high output. The motor shaft 25 extending in the vertical direction is rotatably supported by bearings at the upper and lower ends. The upper end portion of the motor shaft 25 projects into the drive mechanism accommodating portion 117, and the drive gear 29 is formed in this portion. Further, as shown in FIG. 2, in the rotor 22, permanent magnets 221 are embedded in eight accommodating holes provided in the circumferential direction around the rotation axis A2, respectively, and the motor 2 is an embedded magnet type 8 It is configured as a pole brushless motor.

Further, as shown in FIGS. 1 and 3, the vibration sensor unit 4 is held in the motor accommodating portion 111. In the present embodiment, the vibration sensor unit 4 is arranged within the length range of the motor shaft 25 in the vertical direction, and is arranged behind the motor in the front-rear direction. More specifically, inside the motor accommodating portion 111, an internal wall 112 arranged so as to be orthogonal to the front-rear direction (the normal line is in the front-rear direction) is provided. The vibration sensor unit 4 is held on the back surface of the inner wall 112 above the stator 21 and the rotor 22 and behind the stator 21. The configuration of the vibration sensor unit 4 and its holding structure will be described in detail later.

The drive mechanism accommodating portion 117 and its internal structure will be described. As shown in FIG. 1, the drive mechanism accommodating portion 117 is connected and fixed so as not to be relatively movable with respect to the motor accommodating portion 111 in a state where the lower end portion of the rear side portion is arranged in the upper end portion of the motor accommodating portion 111. ing. The drive mechanism accommodating portion 117 accommodates a drive mechanism 3 configured to drive the tip tool 91 by the power of the motor 2. In the present embodiment, the drive mechanism 3 includes a motion conversion mechanism 30, a striking element 36, and a rotation transmission mechanism 37. The motion conversion mechanism 30 and the striking element 36 are mechanisms for performing a striking motion that linearly drives the tip tool 91 along the drive shaft A1, and the rotation transmission mechanism 37 rotationally drives the tip tool 91 around the drive shaft A1. It is a mechanism that performs a drilling operation.

The motion conversion mechanism 30 is configured to convert the rotational motion of the motor 2 into a linear motion and transmit it to the striking element 36. In this embodiment, a crank mechanism is adopted as the motion conversion mechanism 30. More specifically, the motion conversion mechanism 30 as a crank mechanism includes a crankshaft 31, an articulated rod 32, a piston 33, and a cylinder 35. The crankshaft 31 is arranged at the rear end of the drive mechanism accommodating portion 117 in parallel with the motor shaft 25. The crankshaft 31 has a driven gear that meshes with the drive gear 29 and an eccentric pin. One end of the connecting rod 32 is connected to the eccentric pin, and the other end is connected to the piston 33 via the connecting pin. The piston 33 is slidably arranged in the cylindrical cylinder 35. The cylinder 35 is coaxially connected and fixed to the rear portion of the tool holder 34 arranged in the tip region of the drive mechanism accommodating portion 117 in a coaxial manner with the tool holder 34. When the motor 2 is driven, the piston 33 is reciprocated in the cylinder 35 in the drive shaft A1 direction.

The striking element 36 is configured to operate linearly to strike the tip tool 91 so as to drive the tip tool 91 linearly along the drive shaft A1. In this embodiment, the striking element 36 includes a striker 361 and an impact bolt 363. The striker 361 is slidably arranged in the cylinder 35 in the drive shaft A1 direction. An air chamber 365 for linearly moving the striker 361 as a striking element is formed between the striker 361 and the piston 33 via the pressure fluctuation of the air caused by the reciprocating movement of the piston 33. The impact bolt 363 is configured as a meson that transmits the kinetic energy of the striker 361 to the tip tool 91, and is slidably arranged in the tool holder 34 in the drive shaft A1 direction.

When the motor 2 is driven and the piston 33 is moved forward, the air in the air chamber 365 is compressed and the internal pressure rises. Therefore, the striker 361 is pushed forward at high speed and collides with the impact bolt 363, and kinetic energy is transmitted to the tip tool 91. As a result, the tip tool 91 is driven linearly along the drive shaft A1 and hits the workpiece. On the other hand, when the piston 33 is moved backward, the air in the air chamber 365 expands and the internal pressure drops, and the striker 361 is pulled backward. The motion conversion mechanism 30 and the striking element 36 perform a striking motion by repeating such an motion.

The rotation transmission mechanism 37 is configured to transmit the rotational power of the motor shaft 25 to the tool holder 34. In the present embodiment, the rotation transmission mechanism 37 is configured as a gear reduction mechanism including a plurality of gears, and the rotation power of the motor 2 is appropriately decelerated and then transmitted to the tool holder 34. A meshing type clutch 38 is arranged on the power transmission path of the rotation transmission mechanism 37. When the clutch 38 is placed in the engaged state, the rotation transmission mechanism 37 transmits the rotational power of the motor shaft 25 to the tool holder 34, so that the tip tool 91 mounted on the tool holder 34 is driven by the drive shaft A1. Performs a drill operation that is driven to rotate around. On the other hand, when the clutch 38 is disengaged (FIG. 1 shows the disengaged state), the power transmission to the tool holder 34 by the rotation transmission mechanism 37 is cut off, and the tip tool 91 rotates. Not driven.

The hammer drill 1 of the present embodiment is configured to be able to select one of two operation modes, a hammer drill mode and a hammer mode, by operating a mode switching dial 39 rotatably arranged at the upper end portion of the drive mechanism accommodating portion 117. Has been done. The hammer drill mode is an operation mode in which the striking operation and the drill operation are performed by engaging the clutch 38 and driving the motion conversion mechanism 30 and the rotation transmission mechanism 37. The hammer mode is an operation mode in which only the striking operation is performed by disengaging the clutch 38 and driving only the motion conversion mechanism 30. Inside the first housing 11 (specifically, inside the drive mechanism accommodating portion 117), the mode switching dial 39 is connected, and when the hammer drill position or the hammer position is selected by the mode switching dial 39, the selected switching position is set. A clutch switching mechanism configured to switch the clutch 38 between the engaged state and the disengaged state is provided accordingly. Since the configuration of the clutch switching mechanism is a well-known technique, detailed description and illustration thereof are omitted here.

Hereinafter, the detailed configuration of the second housing 13 and its internal structure will be described with reference to FIG. 1.

First, the upper portion 133 and its internal structure will be described. As shown in FIG. 1, the rear portion of the upper portion 133 is formed in a substantially rectangular box shape with the lower side open, and the rear portion of the drive mechanism accommodating portion 117 (more specifically, the motion conversion mechanism 30 and the motion conversion mechanism 30 and the rear portion). The portion in which the rotation transmission mechanism 37 is housed) is covered from above. Further, the front side portion of the upper side portion 133 is formed in a cylindrical shape and covers the outer periphery of the front side portion of the drive mechanism accommodating portion 117 (more specifically, the portion accommodating the tool holder 34). An opening is formed on the upper surface of the rear portion of the upper portion 133, and the mode switching dial 39 provided at the upper end portion of the drive mechanism accommodating portion 117 is exposed to the outside from this opening.

The grip portion 131 and its internal structure will be described. As shown in FIG. 1, a trigger 14 that can be pressed by an operator is provided on the front portion of the grip portion 131. Inside the grip portion 131 formed in a cylindrical shape, a switch 145 that is switched between an on state and an off state according to the operation of the trigger 14 is provided.

The lower portion 137 and its internal structure will be described. As shown in FIG. 1, the lower portion 137 is formed in a rectangular box shape with a partially open upper side, and is arranged below the motor accommodating portion 111. A controller 6 is arranged inside the lower portion 137. In the present embodiment, as the controller 6, a control circuit composed of a microcomputer including a CPU, ROM, RAM, and the like is adopted. The controller 6 is electrically connected to the motor 2, the switch 145, the battery mounting portion 15, the vibration sensor unit 4, and the like by wiring (not shown).

When the trigger 14 is pressed and the switch 145 is turned on, the controller 6 starts energizing the motor 2 (that is, driving the tip tool 91), the pressing operation of the trigger 14 is released, and the switch 145 is pressed. When it is in the off state, the energization of the motor 2 is stopped. Further, in the present embodiment, the controller 6 drives the motor 2 at a low rotation speed from the start of driving the motor 2 to the no-load state, and drives the motor 2 at a high rotation speed when the motor 2 is in the load state. It is configured to provide control. In the present embodiment, when the vibration caused by the striking operation of the drive mechanism 3 exceeds a predetermined range, it is determined that the motor 2 is in the load state. Therefore, in the present embodiment, the vibration sensor unit 4, which will be described later, detects the vibration caused by the striking motion.

Further, as described above, at the lower end of the central portion of the lower portion 137 in the front-rear direction, two battery mounting portions 15 are provided so that the rechargeable battery 93 can be attached and detached. In this embodiment, the two battery mounting portions 15 are arranged side by side in the front-rear direction. The battery 93 is slidably engaged from the left side to the right side with respect to the battery mounting portion 15, and is electrically connected to the battery mounting portion 15. When the two batteries 93 are mounted on the battery mounting portion 15, the lower surfaces of the two batteries 93 are flush with each other. Further, the front lower end portion 138 and the rear lower end portion 139 of the lower portion 137 are arranged on the front side and the rear side of the battery 93, respectively, when the battery 93 is mounted on the battery mounting portion 15, and the lower surface thereof is a battery. It is configured to be substantially flush with the lower surface of the 93, and functions as a battery protection unit that protects the battery 93 from external forces.

Hereinafter, the configuration of the vibration sensor unit 4 and its holding structure will be described with reference to FIGS. 1 and 3 to 5.

As shown in FIGS. 3 and 4, in the present embodiment, the vibration sensor unit 4 includes a sensor main body 40 and a holding member 41 for holding the sensor main body 40. Although detailed illustration is omitted, the sensor main body 40 is equipped with a vibration sensor for detecting vibration and a microcomputer including a CPU, ROM, RAM and the like. In this embodiment, a well-known acceleration sensor is adopted as the vibration sensor, but other sensors (speed sensor, displacement sensor, etc.) capable of detecting vibration may be adopted. The microcomputer determines whether or not the vibration detected by the vibration sensor exceeds a predetermined threshold value, and outputs a signal (off signal or on signal) according to the determination result to the controller 6 (see FIG. 1). It is configured. The sensor main body 40 is not provided with a microcomputer, and a signal indicating the detection result of the vibration sensor may be output to the controller 6 as it is, and the controller 6 may make a judgment. The holding member 41 is formed in a plate shape as a whole, and has a holding portion 411 having a rectangular shape in a rear view and a pair of arm portions 413 protruding from the holding portion 411 in the left-right direction. The sensor body 40 is held in a recess formed in the holding portion 411. Through holes 415 are formed in each of the arm portions 413.

The internal wall 112 of the motor accommodating portion 111 has a pair of cylindrical portions 113 that are arranged apart from each other on the left and right and project to the rear in a region slightly above the stator 21 and the rotor 22. The separation distance of the pair of cylindrical portions 113 is substantially equal to the separation distance of the pair of through holes 415 provided in the holding member 41, and the outer diameter of the cylindrical portion 113 is provided in the arm portion 413 of the holding member 41. Slightly smaller than the through hole 415. The protruding length (length in the front-rear direction) of the cylindrical portion 113 is larger than the thickness of the arm portion 413 of the holding member 41. A screw hole 114 is formed on the inner peripheral surface of the cylindrical portion 113.

The vibration sensor unit 4 is held by the inner wall 112 via two elastic intervening members 45. As shown in FIG. 5, in the present embodiment, each elastic intervening member 45 is composed of an annular first elastic body 451 and a second elastic body 453 integrally connected by a string-shaped connecting portion 455. .. In the present embodiment, each elastic intervening member 45 is configured as one component integrally molded by rubber. The hardness of the rubber is about 50 degrees. Further, as shown in FIG. 4, the first elastic body 451 and the second elastic body 453 have a substantially circular cross section. That is, the elastic intervening member 45 of the present embodiment can be rephrased as two O-rings connected by a string.

When the vibration sensor unit 4 is connected to the inner wall 112, first, the first elastic body 451 of the elastic intervening member 45 is fitted into the outer peripheral portion of the cylindrical portion 113, respectively. At this time, as shown by the alternate long and short dash line in FIG. 4, since the second elastic body 453 is connected to the first elastic body 451 by the connecting portion 455, it is in a state of hanging in the vicinity of the cylindrical portion 113. After that, the cylindrical portions 113 are inserted into the through holes 415 of the holding member 41 of the vibration sensor unit 4, respectively. Further, the second elastic body 453 of the elastic intervening member 45 is fitted into the outer peripheral portion of the cylindrical portion 113, respectively. That is, the vibration sensor unit 4 (holding member 41) is sandwiched between the first elastic body 451 and the second elastic body 453 in the front-rear direction. In this state, the vibration sensor unit 4 is held by the inner wall 112 by screwing the screw 48 into the screw hole 114 of the cylindrical portion 113 via the washer 47. When the screw 48 is screwed, the first elastic body 451 and the second elastic body 453 are held in a slightly compressed state. Further, the connecting portion 455 connecting the first elastic body 451 and the second elastic body 453 is arranged on the side of the arm portion 413.

With such a structure, the vibration sensor unit 4 is held so as to be relatively movable in the front-rear direction (that is, in the drive shaft A1 direction) with respect to the internal wall 112. A recess 115 is formed on the back surface of the inner wall 112.

By the way, in the present embodiment, the sensor body (vibration sensor) 40 reliably determines the vibration caused by the striking operation, which is used as a criterion for determining whether or not the motor 2 is in the load state, among the vibrations generated in the first housing 11. Need to be detected. Therefore, the vibration sensor unit 4 including the sensor main body 40 is held in the first housing 11 that houses the drive mechanism 3 that is the vibration source. On the other hand, regarding other vibrations, it is preferable that the vibrations are not transmitted to the sensor body 40 as much as possible in order to reduce the possibility of malfunction of the sensor body 40 which is a precision instrument.

Generally, the vibration caused by the striking motion is a vibration having a relatively low frequency. In the hammer drill 1 of the present embodiment, the frequency of vibration caused by the striking motion (hereinafter, also referred to as striking frequency) is about 50 Hz. On the other hand, when the motor 2 (see FIG. 2) is driven, the rotor 22 having a magnetic force rotates, and electromagnetic vibration having a frequency specified according to the number of poles of the rotor 22 (8 in this embodiment) is generated. Then, it is transmitted to the first housing 11. The vibration caused by this electromagnetic vibration is a relatively large vibration other than the vibration caused by the striking motion, and is a vibration having a higher frequency. In the present embodiment, the frequency of vibration caused by the electromagnetic vibration of the motor 2 (hereinafter, also referred to as electromagnetic vibration frequency) is about 2,400 Hz.

Therefore, the vibration sensor unit 4 has a vibration of the first frequency caused by the striking operation of the drive mechanism 3 among the vibrations generated in the first housing 11 via the elastic intervening member 45 configured as described above (in detail). Can detect vibration in a frequency band having a certain width centered on the striking frequency and its order component, and vibration of the second frequency caused by the electromagnetic vibration of the motor 2 (specifically, the electromagnetic vibration frequency). The transmission of (vibration of a frequency band having a certain width centered on the order component) is suppressed and is held by the inner wall 112. That is, the vibration of the first frequency caused by the striking operation is surely transmitted to the sensor main body 40, while the sensor main body 40 is protected from the vibration of the second frequency caused by the electromagnetic vibration of the motor 2. ..

Hereinafter, the operation of the hammer drill 1 will be described.

When the user selects the hammer drill mode or the hammer mode with the mode switching dial 39 and presses the trigger 14, the controller 6 starts driving the motor 2 at a low rotation speed. As described above, when the hammer drill mode is selected, the drive mechanism 3 performs a striking operation and a drill operation, and when the hammer mode is selected, the drive mechanism 3 performs only a striking operation. .. As a result, vibration caused by the striking motion and vibration caused by the electromagnetic vibration are generated in the first housing 11, but the second housing caused by the electromagnetic vibration detected by the sensor main body 40 due to the effect of the elastic intervening member 45 described above. The frequency vibration is negligibly smaller than the first frequency vibration caused by the striking motion, and the vibration sensor of the sensor body 40 reliably detects the first frequency vibration caused by the striking motion. be able to. When the vibration sensor detects vibration exceeding a predetermined threshold value, the microcomputer of the sensor main body 40 outputs a specific signal when the vibration exceeds the threshold value to the controller 6. The controller 6 switches the rotation speed of the motor 2 to a high rotation speed in response to this signal. When the user releases the pressing operation of the trigger 14, the controller 6 stops driving the motor 2.

As described above, according to the hammer drill 1 of the present embodiment, the vibration sensor unit 4 (sensor body 40) causes the first frequency caused by the striking operation of the drive mechanism 3, which is a characteristic vibration in the hammer drill 1. Vibration (specifically, vibration in a frequency band having a certain width centered on the striking frequency and its order component) can be detected. On the other hand, from the vibration of the second frequency caused by the electromagnetic vibration of the motor 2 (specifically, the vibration of the frequency band having a certain width centered on the electromagnetic vibration frequency and its order component), the sensor body (vibration sensor). ) 40 can be protected. As described above, in this embodiment, rational protection of the sensor body (vibration sensor) 40, which is an example of precision equipment, is realized.

In the present embodiment, the vibration sensor unit 4 accommodates the motor 2 and the drive mechanism 3 via two elastic intervening members 45, each of which includes two elastic bodies (first elastic body 451 and second elastic body 453). It is held in the first housing 11 (inner wall 112). That is, due to the simple holding structure in which the elastic intervening member 45 is arranged in an intervening manner between the vibration sensor unit 4 and the first housing 11, the vibration of the first frequency caused by the striking operation is detected and the vibration is electromagnetic. The sensor body (vibration sensor) 40 can be protected from the resulting vibration of the second frequency.

Further, the vibration sensor unit 4 is held in the first housing 11 in a state of being sandwiched between the first elastic body 451 and the second elastic body 453 in the front-rear direction. Therefore, according to this aspect, the vibration of the second frequency from the first housing 11 to the vibration sensor unit 4 by the first elastic body 451 and the second elastic body 453 arranged in the front-rear direction with the vibration sensor unit 4 interposed therebetween. Can be effectively suppressed. In particular, as in the present embodiment, the first elastic body 451 and the second elastic body 453 having a substantially circular cross-sectional shape are more easily elastically deformed than the elastic body having a rectangular cross section, so that vibration transmission can be suppressed. Is suitable. The cross-sectional shape of the first elastic body 451 and the second elastic body 453 may be not only a perfect circle but also a slightly distorted circle or an ellipse.

Further, the first elastic body 451 and the second elastic body 453 are integrally connected via the connecting portion 455. When the first elastic body 451 and the second elastic body 453 are not connected and are treated as separate parts, the first elastic body 451 that is first fitted into the cylindrical portion 113 during the assembling work as described above. Is hidden by the vibration sensor unit 4, and there is a possibility that it cannot be visually confirmed whether or not it has been assembled. On the other hand, according to the elastic intervening member 45, when one of the first elastic body 451 and the second elastic body 453 is forgotten to be assembled, the assembling worker can immediately and visually recognize the forgotten assembly. can. Further, it is possible to reduce the possibility of loss of the first elastic body 451 and the second elastic body 453, which tend to be small parts.

In the present embodiment, the motor 2 is arranged so as to extend in a direction in which the rotation axis A2 intersects (specifically, orthogonal to) the drive axis A1. The vibration sensor unit 4 is arranged behind the motor 2 within the range of the length of the motor shaft 25 with respect to the extending direction (vertical direction) of the rotating shaft A2. In particular, in the hammer drill 1 having a drive mechanism 3 that employs a crank mechanism for the motion conversion mechanism 30 and a motor 2 that is arranged in a direction in which the rotation shaft A2 intersects the drive shaft A1, as in the present embodiment, the crank. Empty space is likely to occur below the mechanism and behind the motor 2. The vibration sensor unit 4 of the present embodiment is arranged by effectively utilizing this empty space. As a result, a rational arrangement of the vibration sensor unit 4 is realized, which makes it easy to detect the vibration caused by the striking operation.

In the present embodiment, the housing 10 of the hammer drill 1 includes a first housing 11 and a second housing 13 elastically connected to the first housing 11 so as to be elastically connected to the first housing 11. With such a so-called anti-vibration housing structure, it is possible to effectively suppress the vibration of the first housing 11 from being transmitted to the second housing 13 including the grip portion 131 gripped by the user. Further, in the present embodiment, since the controller 6 is housed in the second housing 13 (specifically, the lower portion 137), the controller 6 which is a precision instrument is moved from all the vibrations generated in the first housing 11. Can be properly protected.

The correspondence between each component of the present embodiment and each component of the present invention is shown below. The hammer drill 1 is a configuration example corresponding to the "striking tool" of the present invention. The drive shaft A1 is a configuration example corresponding to the "striking shaft" of the present invention. The motor 2, the stator 21, the rotor 22, the motor shaft 25, and the rotary shaft A2 correspond to the "motor", "stator", "rotor", "motor shaft", and "rotary shaft of the motor shaft" of the present invention, respectively. This is a configuration example. The drive mechanism 3 (motion conversion mechanism 30 and striking element 36) is a configuration example corresponding to the “drive mechanism” of the present invention. The vibration sensor unit 4 (sensor body 40) is a configuration example corresponding to the "vibration sensor" of the present invention. The first housing 11 is a configuration example corresponding to the "first housing" of the present invention. The first elastic body 451 and the second elastic body 453 are configuration examples corresponding to the "at least one elastic body" of the present invention. Further, the first elastic body 451 and the second elastic body 453 and the connecting portion 455 are configuration examples corresponding to the "first elastic body", the "second elastic body", and the "connecting portion" of the present invention, respectively. The second housing 13 and the grip portion 131 are configuration examples corresponding to the "second housing" and the "grip portion" of the present invention. The first spring 71, the second spring 75, and the O-ring 77 are configuration examples corresponding to the "elastic body" of the present invention, respectively. The controller 6 is a configuration example corresponding to the "controller" of the present invention.

[Second Embodiment]
Hereinafter, the hammer drill 100 according to the second embodiment will be described with reference to FIGS. 6 to 11. The hammer drill 100 exemplified in the present embodiment is configured to be capable of performing a striking operation and a drilling operation like the hammer drill 1 of the first embodiment, and includes a configuration common to the hammer drill 1. Therefore, in the following, the same reference numerals will be given to the configurations common to the hammer drill 1, and the description thereof will be omitted or simplified, and the different configurations will be mainly described with reference to the drawings.

First, a schematic configuration of the hammer drill 100 will be described with reference to FIG. As shown in FIG. 6, in the present embodiment, the outer shell of the hammer drill 100 is mainly formed by the main body housing 16 and the handle 17.

The main body housing 16 and its internal structure will be described. In the present embodiment, the main body housing 16 mainly includes three parts of a drive mechanism accommodating portion 161, a motor accommodating portion 163, and a controller accommodating portion 169, and is formed in a substantially Z-shape in side view as a whole. There is.

The drive mechanism accommodating portion 161 is a portion of the main body housing 16 extending in the front-rear direction along the drive shaft A1. The basic internal structure of the drive mechanism accommodating portion 161 is the same as the internal structure of the drive mechanism accommodating portion 117 of the first embodiment (see FIG. 1). That is, the drive mechanism accommodating portion 161 includes a tool holder 34 at the front end portion, and accommodates the drive mechanism 3 including the motion conversion mechanism 300, the striking element 36, and the rotation transmission mechanism 37. In the first embodiment, the motion conversion mechanism 30 configured as the crank mechanism is adopted, whereas in the present embodiment, the motion conversion mechanism 300 using the swing member is adopted. Since the configuration of the motion conversion mechanism 300 is well known, the description thereof is omitted here.

The motor accommodating portion 163 is a portion of the main body housing 16 that is connected to the rear end portion of the drive mechanism accommodating portion 161 and extends substantially in the vertical direction. The motor 2 is accommodated in the central portion of the motor accommodating portion 163 in the vertical direction. Unlike the first embodiment, the motor 2 is arranged so that the rotation shaft of the motor shaft 25 intersects the drive shaft A1 at an angle. More specifically, the rotation shaft of the motor shaft 25 extends diagonally downward and forward with respect to the drive shaft A1. Therefore, the power is transmitted from the motor shaft 25 to the motion conversion mechanism 300 and the rotation transmission mechanism 37 via the bevel gear instead of the spur gear.

The controller accommodating portion 169 is a portion of the main body housing 16 extending rearward from a substantially central portion (area in which the motor 2 is accommodated) in the vertical direction of the motor accommodating portion 163. The controller 6 is housed in the controller housing unit 169. Further, two battery mounting portions 15 are provided below the controller accommodating portion 169. Similar to the first embodiment, the two battery mounting portions 15 are arranged side by side in the front-rear direction.

The lower end portion 164 of the motor accommodating portion 163 is arranged on the front side of the battery 93 when the battery 93 is mounted on the battery mounting portion 15, and the lower surface thereof is configured to be substantially flush with the lower surface of the battery 93. Has been done. The lower end portion 164 also functions as a battery protection portion that protects the battery 93 from an external force. That is, the lower end portion 164 is a portion extended to the lower side of the motor 2 in consideration of ensuring stability when the hammer drill 100 is placed on a flat surface and protecting the battery 93 from an external force. The internal space of the lower end portion 164 having such a configuration tends to be a dead space. Therefore, in the present embodiment, the vibration sensor unit 5 is arranged by effectively utilizing this dead space. The configuration of the vibration sensor unit 5 and its holding structure will be described in detail later.

The handle 17 will be described. The handle 17 includes a grip portion 171, an upper connecting portion 173, and a lower connecting portion 175, and is formed in a substantially C shape as a whole. The grip portion 171 is a portion that extends substantially in the vertical direction apart from the rear of the main body housing 16. The grip portion 171 is provided with a trigger 14 and a switch 145. The upper connecting portion 173 is a portion extending forward from the upper end portion of the grip portion 171 and being connected to the upper rear end portion of the main body housing 16. The lower connecting portion 175 is a portion extending forward from the lower end portion of the grip portion 171 and being connected to the central rear end portion of the main body housing 16. Further, the lower connecting portion 175 is arranged on the upper side of the controller accommodating portion 169.

In this embodiment, the handle 17 is elastically connected to the main body housing 16 so as to be relatively movable. More specifically, an urging spring 174 is interposed between the front end portion of the upper connecting portion 173 and the rear end portion of the drive mechanism accommodating portion 161. On the other hand, the lower connecting portion 175 is rotatably supported with respect to the motor accommodating portion 163 via a support shaft 177 extending in the left-right direction. With such a configuration, vibration transmission from the main body housing 16 to the handle 17 (grip portion 171) is suppressed.

Hereinafter, the configuration of the vibration sensor unit 5 and its holding structure will be described.

As shown in FIG. 7, the vibration sensor unit 5 includes a sensor main body 40 similar to the vibration sensor unit 4 of the first embodiment, and a holding member 51 for holding the sensor main body 40. Further, the vibration sensor unit 5 is held by the lower end portion 164 of the motor accommodating portion 163 via two elastic intervening members 55 engaged with the left and right end portions of the holding member 51.

As shown in FIG. 8, in the present embodiment, the holding member 51 is formed in the shape of a rectangular parallelepiped box having an open front surface and long in the left-right direction as a whole. More specifically, the holding member 51 has a rear wall (bottom wall) 511 and a peripheral wall that projects forward from the outer edge of the rear wall 511 and surrounds the outer edge. The peripheral wall includes a pair of left and right double wall portions 513 and a pair of upper and lower side walls 518. The sensor body 40 is held in a recess defined by the rear wall 511 and the peripheral wall (see FIG. 10).

The double wall portions 513 constituting the left and right ends of the holding member 51 are configured so that the elastic intervening member 55, which will be described later, can be engaged with each other. More specifically, each double wall portion 513 has an inner wall 514 and an outer wall 515, and a space portion 521 formed between them. The outer wall 515 is shorter than the inner wall 514 in the vertical direction, and the upper and lower ends of the outer wall 515 are connected to the inner wall 514. On the other hand, the front and rear ends of the inner wall 514 and the outer wall 515 are open. That is, the space portion 521 between the inner wall 514 and the outer wall 515 is formed as a through hole penetrating the double wall portion 513 in the front-rear direction. Further, between the inner wall 514 and the outer wall 515, a partition wall 523 for partitioning the space portion 521 into two vertical space portions is provided. Further, the outer wall 515 is formed with two openings 524 on the upper side and the lower side of the partition wall 523 to communicate the space portion 521 and the outside of the holding member 51. The engagement protrusion 555 of the elastic intervening member 55 described later is fitted into the opening 524.

Further, recesses 526 are formed at the four corners of the holding member 51. More specifically, the left and right ends of each of the pair of upper and lower side walls 518 are formed so as to project to the left and right (toward the outer wall 515) from the pair of left and right inner walls 514, respectively. The recess 526 is a recess defined by the left and right ends of the side wall 518 and the upper and lower ends of the double wall portion 513, and is recessed inward in the left-right direction. An elastic ring 57 mounted on the outer periphery of the holding member 51 is held in the recess 526.

By the way, the sensor main body 40 (see FIG. 10) held by the holding member 51 needs to be attached to the main body housing 16 (motor accommodating portion 163) in the correct direction in order to accurately detect the vibration caused by the striking motion. be. Therefore, the holding member 51 is provided with a protrusion 531 as a mark for aligning the orientation of the holding member 51 with respect to the main body housing 16 (motor accommodating portion 163). More specifically, the protrusion 531 projects forward from the right front end of the upper side wall 518. Further, in the upper side wall 518, an engaging recess 532 having a shape corresponding to the protrusion 531 is provided on the rear side of the protrusion 531. Therefore, before the sensor main body 40 is assembled to the holding member 51, as shown in FIG. 9, a plurality of protrusions 531 of the holding member 51 are engaged with the engaging recesses 532 of another holding member 51. Holding members 51 can be stacked. As a result, it is possible to eliminate wasted space during transportation and storage of the plurality of holding members 51, and it is possible to reduce the possibility of damage to the protrusion 531.

As shown in FIG. 8, in the present embodiment, each elastic intervening member 55 is formed in a prismatic shape having a substantially isosceles trapezoidal bottom surface as a whole. The side surface having the largest area among the side surfaces of the prism (the side surface corresponding to the lower bottom of the trapezoid) is the double wall portion 513 (specifically, the outer wall 515) when the elastic intervening member 55 is engaged with the holding member 51. It is a surface (hereinafter referred to as an abutting surface 551) arranged so as to abut on the outer surface. The two sides corresponding to the trapezoidal legs constitute a pair of inclined surfaces 552 that incline toward each other as they move away from the abutting surface 551. A step portion including a surface 551 parallel to the contact surface 551 is provided between the contact surface 551 and the inclined surface 552. Another side surface parallel to the contact surface 551 corresponding to the upper bottom of the trapezoid constitutes a protruding end surface 554 when the elastic intervening member 55 is engaged with the holding member 51. The length of the elastic intervening member 55 in the vertical direction is substantially the same as that of the outer wall 515, and the width of the elastic intervening member 55 in the front-rear direction is set to be larger than that of the holding member 51.

From the contact surface 551, two engaging protrusions 555 that can be fitted to the two openings 524 formed in the outer wall 515 project from each other. Further, on the front surface and the rear surface of the engaging projection 555, locking pieces 556 projecting forward and rear respectively are provided. As shown in FIG. 10, the front and rear locking pieces 556 are arranged symmetrically with respect to the center line in the front-rear direction of each engagement protrusion 555. Each locking piece 556 is formed in a triangular cross section, and connects an inclined surface that inclines outward from the protruding end side of the engaging projection 555 toward the root side, and the inclined surface and the engaging projection 555. It has a locking surface that is substantially parallel to the contact surface 551.

The entire elastic intervening member 55 configured as described above, including the engaging projection 555 and the locking piece 556, is integrally molded as one part by rubber. The two elastic intervening members 55 are engaged with the left and right double wall portions 513 by fitting the two engagement protrusions 555 into the two openings 524 of the left and right outer walls 515, respectively. When the engaging projection 555 is fitted into the opening 524, the locking piece 556 passes through the opening 524 while being elastically deformed and is arranged in the space 521. When the locking piece 556 is restored in the space 521, the locking surface of the locking piece 556 abuts on the inner surface of the outer wall 515 to prevent the engaging projection 555 from coming out of the opening 524. The two elastic intervening members 55 engaged with the left and right double wall portions 513 project to the left and to the right, respectively. The inclined surface 552 of the elastic intervening member 55 is diagonally arranged so as to approach each other in the vertical direction as it moves away from the vibration sensor unit 5 in the left-right direction. Further, the surface 553 of the stepped portion parallel to the contact surface 551 and the protruding end surface 554 are arranged so as to be orthogonal to each other in the left-right direction.

As shown in FIG. 8, the elastic ring 57 is an annular member formed of an elastic material (eg, rubber). In this embodiment, two elastic rings 57 are attached to the outer peripheral portion of the holding member 51. One of the elastic rings 57 is engaged with two recesses 526 provided at the upper left end portion and the upper right end portion of the holding member 51, and is mounted so as to surround the outer peripheral portion of the upper end portion of the holding member 51. The other end of the elastic ring 57 is engaged with two recesses 526 provided in the left lower end portion and the right lower end portion of the holding member 51, and is mounted so as to surround the outer periphery of the lower end portion of the holding member 51. In the state of being attached to the holding member 51, a part of the two elastic rings 57 is arranged on the front side and the rear side of the holding member 51, respectively.

As shown in FIGS. 6, 10 and 11, a sensor holding portion 165 for arranging the vibration sensor unit 5 is formed at the rear end portion of the lower end portion 164 of the motor accommodating portion 163. The sensor holding portion 165 is formed as a recess that opens forward, and the left and right ends of the sensor holding portion 165 are elastic intervening members 55 attached to the left and right ends (double wall portion 513) of the holding member 51. Is configured as a fitting portion 166 that can be fitted. More specifically, the fitting portion 166 corresponds to the inclined surface 552 of the elastic intervening member 55, and has an inclined surface that inclines so as to approach each other in the vertical direction toward the outside in the left-right direction, and a protruding end surface of the elastic intervening member 55. Corresponding to 554, it is defined as a plane orthogonal to the left-right direction.

The elastic intervening member 55 is fitted to the fitting portion 166 in a state of being compressed in the vertical direction and the horizontal direction. As a result, the elastic intervening member 55 engages with the main body housing 16 (motor accommodating portion 163) via the pair of inclined surfaces 552 in the vertical direction and the horizontal direction. That is, the vibration sensor unit 5 is connected to the main body housing 16 in the vertical direction and the horizontal direction via the elastic intervening member 55. With such a configuration, the vibration sensor unit 5 from the motor accommodating portion 163 vibrates in the vertical and horizontal directions (typically, vibration in a direction different from the vibration in the drive shaft A direction (front-back direction) caused by the striking motion. ) Can be effectively suppressed from being transmitted. Further, when the elastic intervening member 55 is fitted to the fitting portion 166, the surface 553 of the stepped portion provided at the upper and lower ends of the elastic intervening member 55 adjacent to the inclined surface 552 becomes the fitting portion 166. The upper side and the lower side abut on the left and right wall surfaces that define the sensor holding portion 165. With such a configuration, it is possible to suppress the vibration sensor unit 5 from rotating around an axis extending in the front-rear direction with respect to the motor accommodating portion 163.

Further, the elastic intervening member 55 is restricted from moving in the front-rear direction by the rear wall 167 of the sensor holding portion 165 and a pair of ribs 168 extending in the left-right direction along the upper front end portion and the lower front end portion of the sensor holding portion 165. Has been done. As described above, the width of the elastic intervening member 55 in the front-rear direction is set to be larger than that of the holding member 51, so that the vibration sensor unit 5 is separated from the rear wall 167 and the rib 168 (see FIG. 10). ). Further, a part of the elastic ring 57 mounted on the holding member 51 is interposed between the rear wall 167 and the vibration sensor unit 5 (holding member 51) and between the rib 168 and the vibration sensor unit 5 (holding member 51). ing. With such a configuration, the vibration sensor unit 5 can move relative to the motor accommodating portion 163 in the front-rear direction. The elastic ring 57 allows the vibration sensor unit 5 to move relative to the motor accommodating portion 163 in the front-rear direction due to the striking operation of the drive mechanism 3, and prevents the relative movement exceeding a predetermined amount.

In the present embodiment, the motor accommodating portion 163 joins the left and right halves (hereinafter referred to as the left shell 16A and the right shell 16B) divided into two along the drive shaft A1 (see FIG. 1) to each other. Is formed of. Therefore, the left shell 16A and the right shell have the two elastic intervening members 55 engaged to the left and right ends of the vibration sensor unit 5 fitted to the fitting portions 166 of the left shell 16A and the right shell 16B, respectively. By joining the 16B, the vibration sensor unit 5 can be easily arranged in the sensor holding portion 165. At this time, the elastic intervening member 55 and the sensor holding portion 165 are connected via a pair of inclined surfaces that are inclined so as to approach each other in the vertical direction toward the outside in the left-right direction, whereby the elastic intervening member 55 is connected in the vertical direction. It can be easily fitted to the fitting portion 166 while being compressed in the left-right direction, and can be easily aligned in the up-down direction and the left-right direction.

Similar to the vibration sensor unit 4 of the first embodiment, the vibration sensor unit 5 is caused by the striking operation of the drive mechanism 3 among the vibrations generated in the main body housing 16 via the elastic intervening member 55 configured as described above. The vibration of the first frequency (specifically, the vibration of the frequency band having a certain width centered on the striking frequency and its order component) can be detected, and the vibration of the second frequency caused by the electromagnetic vibration of the motor 2 can be detected. (Specifically, vibration in a frequency band having a constant width centered on the electromagnetic vibration frequency and its order component) is held in the lower end portion 164 of the motor accommodating portion 163 in a suppressed state. That is, the vibration of the first frequency caused by the striking operation is surely transmitted to the sensor main body 40, while the sensor main body 40 is protected from the vibration of the second frequency caused by the electromagnetic vibration of the motor 2. .. As described above, also in this embodiment, rational protection of the sensor body (vibration sensor) 40 is realized.

The correspondence between each component of the present embodiment and each component of the present invention is shown below. The hammer drill 100 is a configuration example corresponding to the "striking tool" of the present invention. The vibration sensor unit 5 (sensor body 40) is a configuration example corresponding to the "vibration sensor" of the present invention. The main body housing 16 is a configuration example corresponding to the "first housing" of the present invention. The two elastic intervening members 55 are configuration examples corresponding to the "at least one elastic body" and the "pair of elastic bodies" of the present invention. The grip portion 171 is a configuration example corresponding to the "grip portion" of the present invention. The pair of inclined surfaces 552 is a configuration example corresponding to the "pair of inclined surfaces" of the present invention.

The above embodiment is merely an example, and the striking tool according to the present invention is not limited to the configuration of the exemplified hammer drill 1. For example, the changes exemplified below can be made. It should be noted that these modifications may be adopted in combination with the hammer drill 1 shown in the embodiment or the invention described in each claim in combination with only one or a plurality of them.

For example, in the above embodiment, as an example of the striking tool, the hammer drills 1 and 100 capable of drilling in addition to the striking motion are mentioned, but the striking tool can only perform the striking motion (that is, the drive mechanism 3). May not be equipped with a rotation transmission mechanism 37). Further, although the crank mechanism type motion conversion mechanism 30 is adopted as the drive mechanism 3 of the hammer drill 1, a swing member type motion conversion mechanism may be adopted. On the contrary, the crank mechanism type motion conversion mechanism 300 may be adopted for the hammer drill 100.

Further, the motor 2 of the above embodiment is configured as an embedded magnet type 8-pole brushless motor, but the type and number of poles of the motor 2 are not limited to this example. For example, the motor 2 may be configured as a surface magnet type brushless motor. When the embedded magnet type is adopted, the arrangement and embedding method of the permanent magnet 221 can be changed as appropriate.

As described above, since the electromagnetic vibration frequency of the motor 2 is defined according to the number of poles formed in the rotor 22, the elastic intervening members 45 and 55 for holding the vibration sensor units 4 and 5 are adopted. The number, material, shape, elastic coefficient, etc. may be changed based on the electromagnetic vibration frequency according to the number of poles. For example, only one elastic intervening member 45 may be provided, or may be formed of an elastic body (spring or the like) other than rubber. Further, the first elastic body 451 and the second elastic body 453 do not necessarily have to be integrally connected by the connecting portion 455, and may be arranged in front of and behind the vibration sensor unit 4 as two separate parts. For example, a hydraulic damper or the like may be adopted instead of the elastic intervening member 45. In either case, the vibration sensor unit 4 may be arranged in a state where the vibration caused by the striking operation can be detected and the transmission of the vibration caused by the electromagnetic vibration is suppressed. Further, the transmission suppression target of the elastic intervening member 45 or other mechanism may be vibration caused by a factor other than electromagnetic vibration (vibration having a frequency different from the electromagnetic vibration frequency). Similarly, the elastic intervening member 55 can be appropriately changed.

Similar to the change of the elastic intervening members 45 and 55, the configuration and the arrangement position of the vibration sensor units 4 and 5 are not limited to the example of the above embodiment, and can be changed as appropriate. For example, in the first embodiment, the vibration sensor unit 4 is arranged so as to be entirely within the length range of the motor shaft 25 in the vertical direction, but a part of the vibration sensor unit 4 is a motor shaft. It may be arranged so as to protrude above the upper end of 25 or below the lower end. Further, for example, the vibration sensor unit 4 may be held on the rear wall of the drive mechanism accommodating portion 117 instead of the internal wall 112 of the motor accommodating portion 111. In this case, the vibration sensor unit 4 may be entirely outside the range of the length of the motor shaft 25 in the vertical direction. Further, the vibration sensor unit 5 of the second embodiment may be arranged at another position in the motor accommodating portion 163, or may be arranged in the controller accommodating portion 169.

In the first embodiment, the housing 10 is configured as a vibration-proof housing including the first housing 11 and the second housing 13, but the housing 10 does not necessarily have to be a vibration-proof housing. Further, the elastic connection structure of the first housing 11 and the second housing 13 may be appropriately changed. Further, in the above embodiment, the grip portion 131 is a part of the second housing 13, but for example, only the grip portion (handle) configured to be grippable by the user accommodates the motor 2 and the drive mechanism 3. It may be connected to the housing portion via an elastic element. From the viewpoint of protection from vibration, it is preferable that the controller 6, which is a precision instrument, is housed in the second housing 13, but it is not excluded that the controller 6 is housed in the first housing 11.

1, 100: Hammer drill 10: Housing 11: First housing 111: Motor accommodating portion 112: Internal wall 113: Cylindrical portion 114: Screw hole 115: Recessed portion 117: Drive mechanism accommodating portion 13: Second housing 131: Grip portion 133: Upper part 137: Lower part 138: Front lower end 139: Rear lower end 14: Trigger 145: Switch 15: Battery mounting part 16: Main body housing 161: Drive mechanism housing part 163: Motor housing part 164: Lower end part 165: Sensor holding part 166: Fitting part 167: Rear wall 168: Rib 169: Controller accommodating part 17: Handle 171: Grip part 173: Upper connecting part 174: Biasing spring 175: Lower connecting part 177: Support shaft 2: Motor 21: Stator 22: Rotor 221: Permanent magnet 25: Motor shaft 29: Drive gear 3: Drive mechanism 30, 300: Motion conversion mechanism 31: Crank shaft 32: Articulated rod 33: Piston 34: Tool holder 35: Cylinder 36: Strike Element 361: Striker 363: Impact bolt 365: Air chamber 37: Rotation transmission mechanism 38: Clutch 39: Mode switching dial 4: Vibration sensor unit 40: Sensor body 41: Holding member 411: Holding part 413: Arm part 415: Through hole 45: Elastic intervening member 451: First elastic body 453: Second elastic body 455: Connecting part 47: Washer 48: Screw 5: Vibration sensor unit 51: Holding member 511: Rear wall 513: Double wall part 514: Inner wall 515 : Outer wall 518: Side wall 521: Space 523: Partition wall 524: Opening 526: Recessed portion 531: Protrusion 532: Engaging recess 55: Elastic intervening member 551: Contact surface 552: Inclined surface 555: Surface 554: Protruding end surface 555: Engagement protrusion 556: Locking piece 57: Elastic ring 6: Controller 71: First spring 75: Second spring 77: O ring 81: Upper sliding part 82: Lower sliding part 91: Tip tool 93: Battery A1 : Drive shaft A2: Rotating shaft

Claims (9)

A striking tool configured to drive a tip tool in a straight line.
With the motor
A drive mechanism configured to drive the tip tool linearly along a striking axis extending in the front-rear direction of the striking tool by the power of the motor.
A first housing that houses the motor and the drive mechanism,
Equipped with a vibration sensor configured to detect vibration,
Among the vibrations generated in the striking tool, the vibration sensor is a state in which the vibration of the first frequency caused by the striking motion can be detected and is a vibration caused by a factor other than the striking motion , and is the first vibration. It is held in the first housing via at least one elastic body in a state where the transmission of the vibration of the second frequency different from the frequency is suppressed.
The at least one elastic body includes a first elastic body and a second elastic body separate from the first elastic body.
The striking tool is characterized in that the vibration sensor is held in the first housing in a state of being sandwiched between the first elastic body and the second elastic body in the front-rear direction. The striking tool according to claim 1.
A striking tool characterized in that the first elastic body and the second elastic body are integrally connected via a connecting portion. A striking tool configured to drive the tip tool in a straight line.
With the motor
A drive mechanism configured to drive the tip tool linearly along a striking axis extending in the front-rear direction of the striking tool by the power of the motor.
A first housing that houses the motor and the drive mechanism,
Equipped with a vibration sensor configured to detect vibration,
Among the vibrations generated in the striking tool, the vibration sensor is in a state where the vibration of the first frequency caused by the striking motion can be detected, and is the vibration caused by a factor other than the striking motion, and is the first vibration. It is held in the first housing via at least one elastic body in a state where the transmission of vibration of a second frequency different from the frequency is suppressed.
The at least one elastic body includes an elastic ring and a pair of elastic bodies.
The elastic ring is attached to the vibration sensor so as to surround the outer peripheral portion of the vibration sensor, and is interposed between the vibration sensor and the first housing on the front side and the rear side of the vibration sensor.
A striking tool characterized in that the pair of elastic bodies are arranged on the left side and the right side of the vibration sensor, respectively, and are interposed between the vibration sensor and the first housing. The striking tool according to claim 3.
Each of the pair of elastic bodies has a pair of inclined surfaces that incline toward each other in the vertical direction as they move away from the vibration sensor in the left-right direction, and the first housing is provided with the pair of inclined surfaces. A striking tool characterized by being engaged. The striking tool according to any one of claims 1 to 4.
The motor is configured as a brushless motor having a stator, a rotor, and a motor shaft extending from the rotor.
The vibration of the second frequency is vibration caused by the electromagnetic vibration of the motor, and is the vibration caused by the electromagnetic vibration of the motor.
The second frequency is a striking tool having a frequency defined according to the number of poles formed in the rotor. The striking tool according to any one of claims 1 to 5.
The motor is arranged so that the rotation axis of the motor shaft extends in a direction intersecting the striking axis.
A striking tool characterized in that at least a part of the vibration sensor is arranged within the length range of the motor shaft with respect to the extending direction of the rotating shaft. The striking tool according to claim 6.
The vibration sensor is a striking tool characterized in that it is arranged behind the motor in the front-rear direction. The striking tool according to any one of claims 1 to 7.
Further equipped with a grip portion configured to be gripped by the user,
A striking tool characterized in that the grip portion is connected to the first housing via an elastic body so as to be relatively movable. The striking tool according to any one of claims 1 to 7.
A second housing connected to the first housing via an elastic body so as to be movable relative to the first housing.
Further equipped with a controller configured to control the drive of the motor based on the detection result of the vibration sensor.
The controller is a striking tool, characterized in that it is housed in the second housing.

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