Rotary impact tool

Abstract

To provide a rotary striking tool that can deal with a phenomenon in which a tool main body excessively rotates around a driving shaft.SOLUTION: A rotary striking tool 100 comprises: a first motor 2; a driving mechanism 3 that can operate in operation modes including a first mode in which at least an operation of rotationally driving a tip tool 101 is performed by the power of the first motor and a second mode in which only an operation of driving the tip tool linearly is performed; a tool holder 30 that is rotationally driven by torque transmitted from the first motor; a second motor 4; a clutch member that is arranged at a transmission position to transmit the torque to the tool holder and is arranged at an interruption position to interrupt the transmission of the torque to the tool holder; and transmission mechanisms 7 and 90 which convert the rotary movement of the second motor to a linear movement and transmit the movement to the clutch member. The second motor, when a tool main body excessively rotates around a driving shaft, moves the clutch member from the transmission position through the transmission mechanisms to interrupt the transmission of the torque.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a rotary impact tool.

Background Art

[0002] There is known a rotary impact tool configured to operate according to a selected mode from a plurality of modes including a mode that performs only a striking operation for linearly driving a tip tool in a direction along a predetermined drive shaft, and a mode that performs at least a rotational operation for rotationally driving the tip tool around the drive shaft. Patent Document 1 describes a hammer drill including a clutch member for switching an operation mode and an operation member having an electric actuator for moving the clutch member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a rotary impact tool, a phenomenon may occur in which the tip tool is locked to the workpiece and the tool body rotates excessively around the drive shaft (also referred to as a kickback phenomenon). Therefore, there has been a demand for a rotary impact tool capable of dealing with the phenomenon in which the tool body rotates excessively around the drive shaft.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms.

[0006] According to one aspect of the present disclosure, a rotary impact tool is provided. The rotary impact tool includes a first motor housed in a tool body, a drive mechanism, a tool holder, a second motor, a clutch member, and a transmission mechanism. The drive mechanism is configured to be selectively operable in a plurality of operation modes including a first mode that at least performs an operation of rotationally driving a tip tool around a drive shaft by the power of the first motor, and a second mode that only performs an operation of linearly driving the tip tool along the drive shaft. The tool holder is configured to removably hold the tip tool. Further, the tool holder is configured to be rotationally driven around the drive shaft by torque transmitted from the first motor. The clutch member is configured to be movable between a transmission position where torque is transmitted to the tool holder by the power of the second motor and a blocking position where transmission of the torque to the tool holder is blocked. The transmission mechanism is configured to convert a rotational motion of the second motor into a linear motion and transmit it to the clutch member. The second motor is configured to switch the operation mode of the drive mechanism to the first mode by moving the clutch member to the transmission position via the transmission mechanism, and to switch the operation mode of the drive mechanism to the second mode by moving the clutch member to the blocking position. Further, the second motor is configured to move the clutch member from the transmission position via the transmission mechanism to block the transmission of torque when the state of the tool body is a state of excessive rotation around the drive shaft.

[0007] According to this embodiment, the rotational motion of the second motor is converted into linear motion by a transmission mechanism and transmitted to a clutch member, and the clutch member is moved between a transmission position for transmitting torque to the tool holder and a blocking position for blocking the transmission of torque to the tool holder, thereby providing a rotary impact tool capable of switching the operation mode of the drive mechanism. Further, the second motor is configured to move the clutch member via the transmission mechanism to block the transmission of torque when the tool body is in a state of rotating excessively around the drive shaft. Therefore, when the tool body is in a state of rotating excessively around the drive shaft, the rotation of the tool body can be stopped. Therefore, according to this embodiment, it is possible to realize the switching of the operation mode and the blocking of the transmission of torque using the same second motor, and a rotary impact tool with improved safety can be provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0009] Hereinafter, representative and non-limiting specific examples of the present disclosure will be described in detail with reference to the drawings. This detailed description is simply intended to show those skilled in the art the details for implementing preferred examples of the present disclosure, and is not intended to limit the scope of the present disclosure. In addition, the additional features and disclosures disclosed below can be used separately or together with other features and disclosures in order to provide a further improved rotary striking tool, its control method, and method of use.

[0010] Also, the combinations of features and steps disclosed in the following detailed description are not essential for practicing the present disclosure in the broadest sense, and are described only for explaining representative specific examples of the present disclosure in particular. Further, the various features of the above and below representative specific examples, as well as the various features described in the independent and dependent claims, do not have to be combined as described in the specific examples here or in the order listed in order to provide additional and useful embodiments of the present disclosure.

[0011] All features described in this specification and / or the claims are intended to be disclosed separately and independently of each other, as limitations on the original disclosure and the claimed subject matter, apart from the configuration of the features described in the embodiments and / or claims. Further, all descriptions of numerical ranges and groups or collections are made with the intention of disclosing intermediate configurations as limitations on the original disclosure and the claimed subject matter.

[0012] In one or more embodiments, the clutch member may be provided on the tool holder and configured to be movable along the drive shaft. Further, the transmission position and the cutoff position may be positions in a direction along the drive shaft. Additionally, the transmission mechanism may be configured to convert the rotational motion of the second motor into linear motion along the drive shaft and transmit it to the clutch member.

[0013] According to the above configuration, in a configuration where a clutch member is provided on the tool holder and the transmission mechanism converts the rotational motion of the second motor into linear motion along the drive shaft and transmits it to the clutch member, when the tool body is in a state of rotating excessively around the drive shaft, the rotation of the tool body can be stopped. Also, switching of the operation mode and cutoff of torque transmission can be realized using the same second motor.

[0014] In one or more embodiments, the rotary impact tool may include a rotation detection unit configured to detect the rotational state of the tool body around the drive shaft, and a control unit configured to be able to control the driving of the first motor and the second motor. The control unit may be configured to determine, using the detection result of the rotation detection unit, whether the state of the tool body is a state of rotating excessively around the drive shaft. Further, the control unit may be configured to stop the first motor and drive the second motor to move the clutch member from the transmission position when the state of the tool body is a state of rotating excessively around the drive shaft.

[0015] According to the above configuration, when the state of the tool body is in a state of excessive rotation around the drive shaft, the control unit controls the second motor to cut off the torque transmission and stops the first motor as the power source for driving the tip tool, so that the safety of the rotary impact tool can be further improved.

[0016] In one or more embodiments, the rotary impact tool may include a mode detection unit. The mode detection unit may include a first detection unit configured to detect that the operation mode of the drive mechanism is the first mode, and a second detection unit configured to detect that the operation mode of the drive mechanism is the second mode.

[0017] According to the above configuration, a rotary impact tool capable of detecting the operation mode of the drive mechanism can be provided.

[0018] In one or more embodiments, the control unit may be configured to stop the second motor according to the detection result of the mode detection unit.

[0019] According to the above configuration, since the second motor is stopped according to the detection result of the mode detection unit, the timing of stopping the second motor can be controlled by using the mode detection unit.

[0020] In one or more embodiments, the transmission mechanism may include a first member. The first member may be operably connected to the second motor and the clutch member and may be configured to be moved by the second motor. Further, the tool body may further include a stopper. The stopper may be configured to interfere with the first member to position the clutch member at the transmission position and to interfere with the first member to position the clutch member at the cutoff position.

[0021] According to the above configuration, by the stopper interfering with the first member, the clutch member can be positioned at the transmission position and also at the blocking position. Therefore, compared with a configuration without a stopper, the positioning accuracy of the clutch member can be improved.

[0022] In one or more embodiments, the first member may be configured to be movable in a first direction parallel to the drive shaft and in a second direction opposite to the first direction. The stopper may include a first surface and a second surface that intersect the moving direction of the first member. The first surface may be configured to position the clutch member at the transmission position by interfering with the first member when the first member moves in the first direction. The second surface may be configured to position the clutch member at the blocking position by interfering with the first member when the first member moves in the second direction.

[0023] According to the above configuration, by using the first surface and the second surface of the stopper, the clutch member can be accurately positioned at the transmission position or the blocking position.

[0024] In one or more embodiments, the rotation axis of the second motor may extend in a direction intersecting the drive shaft. Also, the second motor may be arranged on the drive shaft.

[0025] According to the above configuration, compared with a configuration in which the rotation axis of the second motor is arranged parallel to the drive shaft and the second motor is arranged at a position different from that on the drive shaft, the second motor can be arranged near the clutch member, so that the transmission mechanism can be configured compactly. Therefore, the rotary impact tool can be made small.

[0026] In one or more embodiments, the transmission mechanism may include a pinion gear and a rack gear. The pinion gear may be configured to be rotated by the second motor. The rack gear may be configured to engage with the pinion gear and convert the rotation of the pinion gear into the linear motion along the drive shaft direction.

[0027] According to the above configuration, by converting the rotation of the second motor into the linear motion along the drive shaft via the pinion gear and the rack gear, the clutch member can be moved along the drive shaft. Also, the conversion from the rotational motion to the linear motion can be easily realized.

[0028] In one or more embodiments, the rotary impact tool may include a main operation member, a lock member, and a lock control member. The main operation member may be normally maintained at an off position and configured to move to an on position by being pressed by a user to drive the first motor. The lock member may be configured to be movable between a lockable position where the main operation member can be locked at the on position and a non-lockable position where the main operation member cannot be locked at the on position by a user's operation. The lock control member may be disposed at a position interfering with the lock member in the first mode and configured to maintain the lock member at the non-lockable position. Further, the lock control member may be disposed at a position not interfering with the lock member in the second mode and configured to allow the movement of the lock member to the lockable position.

[0029] According to the above configuration, when the tip tool is in the second mode where it only performs a striking operation, the lock control member is configured to allow the lock member to move to the lockable position. Therefore, in a machining operation where the striking operation is continuously performed for a relatively long time, the user does not have to continuously press the second operating member. As a result, the burden on the user during the machining operation can be reduced. Also, when the tip tool is in the first mode where it performs a rotating operation, the lock control member holds the lock member in the non-lockable position. Thus, for example, even if the tip tool is locked to the workpiece, the user can stop the drive of the motor simply by releasing the pressure on the second operating member. Therefore, a highly safe rotary impact tool can be provided.

[0030] In one or more embodiments, the rotary impact tool may include a handle, a rotation detection unit, and an elastic member. The handle may have a grip portion that extends in a direction intersecting the drive shaft and is gripped by the user. The elastic member may connect the handle to the tool body so as to be relatively movable in a direction along the drive shaft. Further, the rotation detection unit may be housed in the handle.

[0031] According to the above configuration, since the rotation detection unit is housed in the handle that is relatively movably connected to the tool body by the elastic member, the vibration of the tool body transmitted to the rotation detection unit can be reduced. Therefore, the service life of the rotation detection unit can be extended.

[0032] In one or more embodiments, the rotary impact tool may include a mode switching operation unit. The mode switching operation unit may be configured to be manually operated by the user for selecting the operation mode of the drive mechanism. Further, the mode switching operation unit may be configured as an electronic switch disposed without providing a gap between it and the outer surface of the tool body.

[0033] According to the above configuration, a rotary impact tool capable of switching the operation mode of the drive mechanism by driving the second motor with the mode switching operation unit can be provided. Further, since the mode switching operation unit can be configured as an electronic switch for driving the second motor, the structure of the mode switching operation unit can be simplified. As a result, the mode switching operation unit can be arranged without providing a gap between the outer surface of the tool body. Therefore, the design property of the rotary impact tool can be improved. Further, since dust or the like does not enter between the mode switching operation unit and the tool body, the mode switching operation unit can have a long service life.

[0034] In one or more embodiments, the second motor may be configured not to be driven in response to an operation of the mode switching operation unit when the first motor is driven.

[0035] According to the above configuration, wear and damage of clutch members and components constituting the rotary impact tool due to the driving of the second motor when the mode switching operation unit is operated during the driving of the first motor can be suppressed.

[0036] In one or more embodiments, the rotary impact tool may include a notification unit configured to notify the operation mode of the drive mechanism.

[0037] According to the above configuration, a rotary impact tool capable of notifying the user of the selected operation mode can be provided.

[0038] <Embodiment> Hereinafter, with reference to FIGS. 1 to 11, a rotary impact tool according to an embodiment will be described. In the present embodiment, as an example of the rotary impact tool, a hammer drill 100 will be described. The hammer drill 100 is configured to be capable of performing an operation of rotationally driving a tip tool 101 attached to a tool holder 30 around a predetermined drive shaft A1 (hereinafter referred to as a rotation operation), and an operation of linearly driving the tip tool 101 parallel to the drive shaft A1 (hereinafter referred to as a percussion operation).

[0039] First, with reference to FIG. 1, the overall configuration of the hammer drill 100 will be briefly described. As shown in FIG. 1, the hammer drill 100 is composed of a tool body 10 and a handle 17 connected to the tool body 10.

[0040] The tool body 10 includes a gear housing 12 extending along the drive shaft A1, and a motor housing 13 connected to one end of the gear housing 12 in the longitudinal axis direction and extending in a direction intersecting the drive shaft A1. In this embodiment, the motor housing 13 extends in a direction substantially orthogonal to the drive shaft A1. With such a configuration, the tool body 10 is generally formed in an L shape as a whole.

[0041] Inside the other end of the gear housing 12 in the longitudinal axis direction, a tool holder 30 configured to be detachable from the tip tool 101 is disposed. Further, a drive mechanism 3 is housed in the gear housing 12. Although details will be described later, the drive mechanism 3 is configured to be selectively operable in a plurality of operation modes including a mode that performs a rotational operation and a striking operation (hereinafter, the rotational-striking mode) and a mode that performs only the striking operation (hereinafter, the striking mode). A first motor 2 is housed in the motor housing 13. The first motor 2 is disposed such that the rotation axis A2 of the motor shaft 25 intersects (more specifically, is orthogonal to) the drive shaft A1. The gear housing 12 and the motor housing 13 are connected so as not to be relatively movable.

[0042] The handle 17 includes a grip portion 170 extending in a direction intersecting the drive shaft A1 (more specifically, a direction substantially orthogonal thereto), and connecting portions 173 and 174 protruding from both ends of the grip portion 170 in the longitudinal axis direction in a direction intersecting the grip portion 170 (more specifically, a direction substantially orthogonal thereto). The handle 17 is generally formed in a C shape as a whole. The handle 17 is connected to the end of the tool body 10 on the side opposite to the side where the tool holder 30 is disposed in the longitudinal axis direction of the tool body 10. More specifically, the connecting portion 173 is connected to the gear housing 12, and the connecting portion 174 is connected to the motor housing 13.

[0043] The following describes the detailed configuration of the hammer drill 100. In the following description, for convenience, the extending direction of the drive shaft A1 of the hammer drill 100 (the major axis direction of the gear housing 12) is defined as the front-rear direction of the hammer drill 100, and the end portion side where the tool holder 30 is provided is defined as the front side of the hammer drill 100, and the opposite side is defined as the rear side. Further, the extending direction of the grip portion 170 is defined as the vertical direction of the hammer drill 100, the side where the connecting portion 173 and the gear housing 12 are connected is defined as the upper side, and the opposite side is defined as the lower side. Further, the direction orthogonal to the front-rear direction and the vertical direction is defined as the left-right direction.

[0044] First, the handle 17 will be described. As described above, the handle 17 includes a grip portion 170 extending in the vertical direction, a connecting portion 173 protruding forward from the upper end of the grip portion 170, and a connecting portion 174 protruding forward from the lower end of the grip portion 170. As shown in FIG. 1, elastic members 175 and 176 are respectively disposed between the connecting portion 173 and the rear upper end portion of the gear housing 12, and between the connecting portion 174 and the rear lower end portion of the motor housing 13. In the present embodiment, compression coil springs are employed as the elastic members 175 and 176. The handle 17 is connected to the tool body 10 via the elastic members 175 and 176 so as to be relatively movable in the front-rear direction. With such a configuration, vibrations transmitted from the tool body 10 to the handle 17 (particularly, vibrations in the front-rear direction caused by the impact operation) are reduced.

[0045] The gripping portion 170 is provided with a switch lever 171. The switch lever 171 is located on the front side of the gripping portion 170 and is arranged from a substantially middle position in the vertical direction of the gripping portion 170 to the upper side. The switch lever 171 is configured to be operable by a pressing operation of the user. In FIG. 2, the off position of the switch lever 171 is shown by a solid line, and the on position is shown by a two-dot chain line. The switch lever 171 is constantly biased forward by a plunger of a main switch 172 provided behind the switch lever 171, and thus is held in the off position. By the pressing operation of the user, it is drawn into the gripping portion 170 and moves to the rear on position. When the switch lever 171 moves to the on position, the main switch 172 housed in the handle 17 is turned on, and the first motor 2 is driven under the control of a controller 9 described later.

[0046] A lock mechanism 8 is provided near a connecting portion 173 of the handle 17. The lock mechanism 8 is a mechanism configured to be able to lock the switch lever 171 in the on position when the operation mode is the impact mode, and to be unable to lock the switch lever 171 in the on position when the operation mode is the rotary impact mode. The lock mechanism 8 will be described later.

[0047] An acceleration sensor 95 is housed in the handle 17. In the present embodiment, the acceleration sensor 95 is housed in the lower end portion of the gripping portion 170 and is arranged at a position relatively far from the drive shaft A1. The acceleration sensor 95 is configured to be able to output a signal indicating the detected acceleration to a controller 9 described later. In the present embodiment, the acceleration detected by the acceleration sensor 95 is used as an index indicating the rotational state around the drive shaft A1 of the tool body 10.

[0048] Next, the internal structure of the motor housing 13 will be described. The motor housing 13 mainly houses a first motor 2 and a controller 9.

[0049] As shown in FIG. 1, the first motor 2 includes a motor main body 20 including a stator and a rotor, and a motor shaft 25 extending from the rotor. The rotation axis A2 of the first motor 2 (motor shaft 25) extends in the vertical direction. In the present embodiment, as the first motor 2, an AC motor that is driven by receiving power supply from an external power source via a power cord 19 is adopted. The motor shaft 25 is rotatably supported by bearings at its upper and lower ends. The upper end portion of the motor shaft 25 protrudes into the gear housing 12, and a drive gear 29 is formed at this portion.

[0050] The controller 9 is attached to the rear wall 132 of the motor main body 20. In the present embodiment, the controller 9 is composed of a microcomputer including a CPU and a memory, etc., and the CPU is configured to control the operation of the hammer drill 100. The controller 9 is electrically connected to the main switch 172, the acceleration sensor 95, the mode detection unit 90 (both will be described later), the mode switching operation unit 6, and the notification unit 61 via electric wires (not shown). In the present embodiment, when the main switch 172 is turned on, the controller 9 drives the first motor 2 according to the rotation speed set via an adjustment dial (not shown). Further, although details will be described later, the controller 9 is configured to control the drive of the second motor 4 according to the operation of the mode switching operation unit 6 and the detection result of the mode detection unit 90. Furthermore, the controller 9 is configured to control the drives of the first motor 2 and the second motor 4 (to be described later) using the detection results of the acceleration sensor 95 and the mode detection unit 90.

[0051] Next, the gear housing 12 will be described. The gear housing 12 is provided with a mode switching operation unit 6 and a notification unit 61.

[0052] The mode switching operation unit 6 is an electronic switch configured to be manually operated by the user for selecting an operation mode. As shown in FIGS. 1, 2, 5, and 7, in the present embodiment, the mode switching operation unit 6 is provided on the upper surface 122 of the gear housing 12, near the connection portion with the connecting portion 173. As shown in FIG. 3, the mode switching operation unit 6 has three switches 60h, 60n, and 60d for selecting an operation mode. The switch 60h is a switch corresponding to the striking mode. The switch 60n is a switch corresponding to the neutral mode described later. The switch 60d is a switch corresponding to the rotary striking mode. In the present embodiment, each of the switches 60h, 60n, and 60d is configured as an electronic switch that outputs an on signal to the controller 9 when pressed. Note that in the present embodiment, the mode switching operation unit 6 is arranged without providing a gap with the upper surface 122. Therefore, dust generated by the processing operation does not enter between the mode switching operation unit 6 and the upper surface 122.

[0053] The notification unit 61 is configured to be able to notify the user of the selected operation mode. In the present embodiment, as shown in FIG. 3, the notification unit 61 is provided on the front side of the mode switching operation unit 6. The notification unit 61 has three LED (Light Emitting Diode) lamps 61h, 61n, and 61d, which are lit under the control of the controller 9, respectively. Specifically, the LED lamp 61h is lit in response to the on state of the switch 60h (that is, when the striking mode is selected). The LED lamp 61n is lit in response to the on state of the switch 60n (that is, when the neutral mode is selected). The LED lamp 61d is lit in response to the on state of the switch 60d (that is, when the rotary striking mode is selected).

[0054] Next, the internal structure of the gear housing 12 will be described.

[0055] The gear housing 12 mainly houses a tool holder 30, a drive mechanism 3, a transmission mechanism 7, a second motor 4, and a mode detection unit 90. The front part of the gear housing 12 is generally formed in a cylindrical shape along the drive shaft A1, and the tool holder 30 is housed in this cylindrical part (also referred to as the barrel part). Although not shown in the figure, an auxiliary handle for assisting in gripping the hammer drill 100 can be attached to the barrel part.

[0056] The drive mechanism 3 includes a motion conversion mechanism 31, a striking mechanism 33, and a rotational transmission mechanism 35. Most of the motion conversion mechanism 31 and the rotational transmission mechanism 35 are housed in the rear part of the gear housing 12.

[0057] The motion conversion mechanism 31 is configured to convert the rotational motion of the first motor 2 into a linear motion and transmit it to the striking mechanism 33. In this embodiment, a well-known crank mechanism is adopted as the motion conversion mechanism 31. As shown in FIG. 2, the motion conversion mechanism 31 includes a crankshaft 311, a connecting rod 313, and a piston 315. The crankshaft 311 is arranged parallel to the motor shaft 25 at the rear end of the gear housing 12. The crankshaft 311 has a driven gear 312 that meshes with the drive gear 29. One end of the connecting rod 313 is connected to an eccentric pin, and the other end is connected to the piston 315 via a connecting pin. The piston 315 is slidably arranged in a cylindrical cylinder 317. When the first motor 2 is driven, the piston 315 reciprocates (in the front-rear direction) along the drive shaft A1 within the cylinder 317.

[0058] The striking mechanism 33 includes a striker 331 and an impact bolt 333 (see FIG. 1). The striker 331 is disposed on the front side of the piston 315 so as to be slidable back and forth in the cylinder 317. An air chamber 335 is formed between the striker 331 and the piston 315 for linearly moving the striker 331 via the pressure fluctuations of the air generated by the reciprocating movement of the piston 315. The impact bolt 333 is configured as an intermediate member for transmitting the kinetic energy of the striker 331 to the tip tool 101. As shown in FIG. 1, the impact bolt 333 is disposed in the tool holder 30 coaxially with the cylinder 317 so as to be slidable back and forth.

[0059] When the first motor 2 is driven and the piston 315 is moved forward, the air in the air chamber 335 is compressed and the internal pressure rises. The striker 331 is pushed forward at high speed by the action of the air spring and collides with the impact bolt 333, transmitting the kinetic energy to the tip tool 101. Thereby, the tip tool 101 is linearly driven parallel to the drive shaft A1 to strike the workpiece. On the other hand, when the piston 315 is moved backward, the air in the air chamber 335 expands and the internal pressure decreases, and the striker 331 is drawn backward. The hammer drill 100 performs a striking operation by repeating such an operation in the motion conversion mechanism 31 and the striking mechanism 33.

[0060] The rotation transmission mechanism 35 is configured to transmit the torque of the motor shaft 25 to the tool holder 30. As shown in FIG. 2, in the present embodiment, the rotation transmission mechanism 35 includes a drive gear 29 provided on the motor shaft 25, an intermediate shaft 36, and a clutch mechanism 54. The rotation transmission mechanism 35 is configured as a speed reduction gear mechanism, and the rotational speed sequentially decreases in the order of the motor shaft 25, the intermediate shaft 36, and the tool holder 30.

[0061] The intermediate shaft 36 is arranged parallel to the motor shaft 25 at the upper front side of the first motor 2. A driven gear 362 that meshes with the drive gear 29 is provided at the lower part of the intermediate shaft 36. Also, a small bevel gear 361 is provided at the upper part of the intermediate shaft 36.

[0062] The clutch mechanism 54 is mounted on the tool holder 30. The clutch mechanism 54 is configured to transmit torque from the motor shaft 25 to the tool holder 30 or to cut off the transmission of torque. In the present embodiment, the clutch mechanism 54 includes a gear sleeve 56 having a large bevel gear 561 and a driving sleeve 55. The gear sleeve 56 is rotatably supported around the drive shaft A1 at the periphery of the rear end portion of the tool holder 30. The large bevel gear 561 meshes with the small bevel gear 361 at the upper end portion of the intermediate shaft 36.

[0063] The driving sleeve 55 is formed in a cylindrical shape and is spline-coupled to the outer periphery of the tool holder 30 in front of the gear sleeve 56. That is, the driving sleeve 55 is engaged with the tool holder 30 in a state where circumferential movement with respect to the tool holder 30 is restricted and movement in the front-rear direction is possible.

[0064] In FIGS. 2, 5, and 7, the rearmost position (hereinafter, position Pd) and the foremost position (hereinafter, position Ph) within the movement range of the driving sleeve 55 are shown. When the driving sleeve 55 is moved to the position Pd, it engages with the front end portion of the gear sleeve 56 (see FIG. 5). Thereby, the torque of the first motor 2 can be transmitted to the tool holder 30 via the rotational transmission mechanism 35. As described above, since the motion conversion mechanism 31 is also driven when the first motor 2 is driven, when the first motor 2 is driven with the driving sleeve 55 disposed at the position Pd, in the hammer drill 100, the rotational operation and the striking operation are performed simultaneously. That is, when the driving sleeve 55 is moved to the position Pd, the operation mode of the hammer drill 100 is switched to the rotary percussion mode.

[0065] Further, when the driving sleeve 55 is moved forward from the position Pd, the engagement between the driving sleeve 55 and the gear sleeve 56 is released (see FIG. 7). As a result, the torque of the first motor 2 cannot be transmitted to the tool holder 30 via the rotary transmission mechanism 35. Then, as shown in FIG. 2, when the driving sleeve 55 is moved to the position Ph, it engages with the lock ring 301 fixed to the gear housing 12, and the tool holder 30 cannot rotate around the drive shaft A1. When the first motor 2 is driven in this state, the motion conversion mechanism 31 is driven, and only the striking operation is performed in the hammer drill 100. That is, when the driving sleeve 55 is moved to the position Ph, the operation mode of the hammer drill 100 switches to the striking mode. Thus, in the hammer drill 100, the operation mode is switched by moving the driving sleeve 55 parallel to the drive shaft A1 (in the front-rear direction).

[0066] As shown in FIG. 7, when the driving sleeve 55 is moved between the position Ph and the position Pd, the torque of the first motor 2 cannot be transmitted to the tool holder 30 as described above. Also, since the driving sleeve 55 is not engaged with the lock ring 301, the tool holder 30 is not fixed to the gear housing 12. Therefore, in this state, the user can rotate the tip tool 101 and the tool holder 30 around the drive shaft A1 by gripping the tip tool 101 with a finger and rotating it around the drive shaft A1. That is, the operation mode of the drive mechanism 3 switches to a mode in which the alignment of the tip tool 101 can be performed. This operation mode is also called the "neutral mode".

[0067] Returning to the description of the internal structure of the gear housing 12. In the present embodiment, as shown in FIG. 2, the second motor 4 is disposed on the drive shaft A1 at the rear of the gear housing 12. The second motor 4 includes a motor body 40 having a stator and a rotor, and a motor shaft 41. The motor body 40 is housed in a motor case 123 supported by the gear housing 12. Further, the rotation axis A3 of the motor shaft 41 extends in the vertical direction. The second motor 4 is rotatable, under the control of the controller 9, in a first rotation direction around the rotation axis A3 and a second rotation direction opposite to the first rotation direction. A planetary gear mechanism as a speed reducer is provided above the second motor 4. The rotational movement of the motor shaft 41 is decelerated by the planetary gear mechanism and output from the pinion gear 42. The pinion gear 42 is fixed to the output shaft (second-stage carrier) of the planetary gear mechanism. In the present embodiment, two stages (two sets) of planetary gear mechanisms are provided, but the number is not limited to two.

[0068] The transmission mechanism 7 is configured to convert the rotational movement of the second motor 4 into a linear movement parallel to the drive shaft A1 and transmit it to the driving sleeve 55. As shown in FIGS. 2 and 4, the transmission mechanism 7 includes a pinion gear 42 and a connection member 70. The pinion gear 42 is an output gear rotated by the second motor 4 as described above. The connection member 70 includes a first member 71 formed with a rack gear 712, a second member 72, a third member 73, and an engagement arm 74 that engages with the driving sleeve 55, and is connected in this order from the rear to the front. The connection member 70 is disposed in the gear housing 12 so as to be integrally movable in the front-rear direction. The connection member 70 moves in the front-rear direction via the rack gear 712 due to the rotation of the pinion gear 42. The connection member 70 is configured to move the driving sleeve 55 to the position Ph by moving to the foremost position within the movement range and move the driving sleeve 55 to the position Pd by moving to the rearmost position. In the present embodiment, the connection member 70 moves rearward when the second motor 4 rotates in the first rotation direction and moves forward when the second motor 4 rotates in the second rotation direction.

[0069] Details of the connecting member 70 will be described. The first member 71 is a member extending in the front-rear direction. A rack gear 712 meshing with the pinion gear 42 is provided on the first member 71. When the pinion gear 42 rotates around the rotation axis A3, the rack gear 712 moves parallel to the drive shaft A1 (that is, in the front-rear direction), so that the first member 71 moves in the front-rear direction. In this way, the rotational motion of the second motor 4 is converted into a linear motion parallel to the drive shaft A1 by the pinion gear 42 and the rack gear 712.

[0070] As shown in FIGS. 2 and 4, the first member 71 has a plate-like portion 711 that extends in the front-rear direction and is orthogonal to the vertical direction, and a first convex portion 717 and a second convex portion 718 that project upward from the plate-like portion 711. The first convex portion 717 is provided at the front end of the first member 71, and the second convex portion 718 is provided behind the first convex portion 717 and spaced apart from the first convex portion 717. The rack gear 712 is formed on the lower side (lower surface) of the second convex portion 718. The first member 71 further has a right convex portion 713 that projects to the right from the front end portion of the plate-like portion 711, and a left convex portion 714 that projects to the left from the front end portion of the plate-like portion 711. The right convex portion 713 and the left convex portion 714 are configured to contact a mode detection unit 90 described later.

[0071] As shown in Fig. 4, in the front-rear direction, a stopper 65 that is fixed to the gear housing 12 and extends in the left-right direction is provided between the first convex portion 717 and the second convex portion 718. The stopper 65 includes a front end face 66 and a rear end face 67 that intersect the moving direction of the first member 71 (i.e., the front-rear direction). The stopper 65 is configured to interfere with the first member 71 to position the driving sleeve 55 at the position Ph and to position the driving sleeve 55 at the position Pd. Specifically, as shown in Fig. 4, when the first member 71 moves forward, the rear end face 67 of the stopper 65 abuts against the front end of the second convex portion 718, thereby positioning the connection member 70 at the foremost position within the moving range and positioning the driving sleeve 55 at the position Ph. Further, as shown in Fig. 6, when the first member 71 moves rearward, the front end face 66 of the stopper 65 abuts against the rear end of the first convex portion 717, thereby positioning the connection member 70 at the rearmost position within the moving range and positioning the driving sleeve 55 at the position Pd.

[0072] Return to the description of the connecting member 70. The second member 72 is a rod-shaped member extending in the front-rear direction. The rear end portion of the second member 72 is inserted into the first convex portion 717 of the first member 71 and is connected to the first member 71. In FIG. 4, by showing inside the first convex portion 717, the connection location between the first member 71 and the second member 72 is represented. The third member 73 is a member formed in a rectangular shape, and the front end portion of the second member 72 is connected to the rear end portion of the third member 73. The engaging arm 74 is an elongated plate-shaped member extending in the front-rear direction. As shown in FIG. 2, the rear end portion of the engaging arm 74 is connected to the front end portion of the third member 73. The bifurcated front end portion of the engaging arm 74 is bent downward in a hook shape and engages with an annular groove 551 formed on the outer peripheral portion of the driving sleeve 55. In the present embodiment, a through hole is provided in the rear end portion of the engaging arm 74, and a connecting pin 76 is inserted through the through hole. Further, a torsion spring 77 is held at the left end portion of the front end portion of the third member 73, and the lower end portion of the connecting pin 76 is sandwiched between the two arms of the torsion spring 77 by the biasing force of the torsion spring 77. Note that the arm disposed on the rear side of the connecting pin 76 among the two arms is locked to the third member 73.

[0073] Next, the mode detection unit 90 will be described. The mode detection unit 90 is configured to detect the operation mode of the hammer drill 100 (the current actual operation mode, specifically, the position of the driving sleeve 55). In the present embodiment, the mode detection unit 90 includes a first switch 91 and a second switch 92 disposed on the upper portion of the gear housing 12. In the present embodiment, the first switch 91 and the second switch 92 are push-type microswitches. The first switch 91 and the second switch 92 are configured to output a signal (on signal) to the controller 9 when pressed.

[0074] The first switch 91 is disposed opposite to the right convex portion 713 behind the right convex portion 713 of the first member 71 and is fixed to the gear housing 12. When the connection member 70 moves to the rearmost position (that is, when the driving sleeve 55 moves to the position Pd), the rear end face of the right convex portion 713 abuts against the first switch 91 and pushes the first switch 91 backward, and their positional relationship is adjusted accordingly. Further, the second switch 92 is disposed opposite to the left convex portion 714 in front of the left convex portion 714 of the first member 71 and is fixed to the gear housing 12. When the connection member 70 moves to the foremost position (that is, when the driving sleeve 55 moves to the position Ph), the front end face of the left convex portion 714 abuts against the second switch 92 and pushes the second switch 92 forward, and their positional relationship is adjusted accordingly.

[0075] With such a configuration, the controller 9 can determine the operation mode of the hammer drill 100 from the detection results of the first switch 91 and the second switch 92 (that is, the position of the driving sleeve 55). Specifically, when an on signal is output from the first switch 91 to the controller 9, the operation mode of the hammer drill 100 is the rotary impact mode, and when an on signal is output from the second switch 92 to the controller 9, the operation mode is the impact mode. Further, when no on signal is output from the first switch 91 and the second switch 92, the operation mode is the neutral mode.

[0076] In this embodiment, the controller 9 is configured to control the drive of the second motor 4 using the detection results of the mode switching operation unit 6 and the mode detection unit 90. Specifically, when the controller 9 does not acquire the on-signal of the second switch 92 (that is, the second switch 92 is off) and acquires the on-signal of the switch 60h corresponding to the impact mode, the controller 9 rotates the second motor 4 in the second rotation direction so as to move the connection member 70 to the most forward position. As the pinion gear 42 rotates, the connection member 70 moves forward as the rack gear 712 moves forward, and moves the driving sleeve 55 to the position Ph (see FIGS. 1, 2, and 4). As a result, the operation mode of the hammer drill 100 switches to the impact mode. At this time, as the connection member 70 moves to the most forward position, the second switch 92 is pushed in, and an on-signal is output from the second switch 92 to the controller 9. When the controller 9 acquires the on-signal of the second switch 92, the controller 9 stops the second motor 4.

[0077] Also, when the first switch 91 is off and the controller 9 acquires the on-signal of the switch 60d corresponding to the rotary impact mode, the controller 9 rotates the second motor 4 in the first rotation direction so as to move the connection member 70 to the rearmost position. As the pinion gear 42 rotates, the connection member 70 moves rearward as the rack gear 712 moves rearward, and moves the driving sleeve 55 to the position Pd (see FIGS. 5 and 6). As a result, the operation mode of the hammer drill 100 switches to the rotary impact mode. At this time, as the connection member 70 moves to the rearmost position, the first switch 91 is pushed in, and an on-signal is output from the first switch 91 to the controller 9. When the controller 9 acquires the on-signal of the first switch 91, the controller 9 stops the second motor 4.

[0078] Further, when the first switch 91 or the second switch 92 is on and the controller 9 obtains an on signal of the switch 60n corresponding to the neutral mode, the controller 9 rotates the second motor 4 so as to move the driving sleeve 55 between the position Ph and the position Pd according to the detection result of the current mode detection unit 90. For example, when the controller 9 obtains an on signal from the first switch 91 (that is, when the connecting member 70 is in the rearmost position), the controller 9 rotates the second motor 4 in the second rotation direction so as to move the connecting member 70 forward. Then, when the first switch 91 is turned off, the controller 9 stops the second motor 4. Or, when the controller 9 obtains an on signal from the second switch 92 (that is, when the connecting member 70 is in the foremost position), the controller 9 rotates the second motor 4 in the first rotation direction so as to move the connecting member 70 backward. Then, when the second switch 92 is turned off, the controller 9 stops the second motor 4. By doing so, the driving sleeve 55 is arranged at an intermediate position between the position Ph and the position Pd, and the operation mode of the hammer drill 100 is switched to the neutral mode.

[0079] In addition, in this embodiment, the controller 9 is configured not to drive the second motor 4 even if the mode switching operation unit 6 is operated when the first motor 2 is driven. In this embodiment, the controller 9 is configured to perform drive control of the second motor 4 using the detection results of the above-described mode switching operation unit 6 and the mode detection unit 90 when the first motor 2 stops.

[0080] As described above, when the connection member 70 (the first member 71) moves forward, the connection member 70 is positioned at the foremost position by the second convex portion 718 contacting the rear end surface 67 of the stopper 65 (see FIG. 4). Further, when the connection member 70 (the first member 71) moves backward, the connection member 70 is positioned at the rearmost position by the first convex portion 717 contacting the front end surface 66 of the stopper 65 (see FIG. 6). Therefore, even if the second motor 4 rotates due to inertia after the controller 9 stops the second motor 4 based on the detection result of the mode detection unit 90, the connection member 70 does not move further forward or backward.

[0081] Next, the operation control of the hammer drill 100 by the controller 9 using the detection results of the acceleration sensor 95 and the mode detection unit 90 will be described. In the rotary percussion mode involving a rotary operation, when the tip tool 101 is locked to the workpiece and the tool holder 30 enters a non-rotatable state (also referred to as a locked state or a blocking state), an excessive reaction torque acts on the tool body 10, and a phenomenon (also referred to as a kickback phenomenon) may occur where the tool body 10 rotates excessively around the drive shaft A1.

[0082] In the present embodiment, when the first motor 2 is driven, the controller 9 acquires the detection result of the acceleration sensor 95 and sequentially determines whether the detection result is equal to or greater than a predetermined threshold value. The threshold value is the acceleration threshold value when the tool body 10 is in a state of rotating excessively around the drive shaft A1, and is stored in advance in the memory provided in the controller 9. The threshold value can be obtained through experiments or simulations.

[0083] Further, the controller 9 determines whether the operation mode is the rotary percussion mode using the detection result of the mode detection unit 90. When the controller 9 acquires the on signal of the first switch 91, it determines that the operation mode is the rotary percussion mode.

[0084] When the acceleration is equal to or greater than the threshold value and the operation mode is the rotary impact mode, the controller 9 rotates the second motor 4 in the second rotation direction. By doing so, the driving sleeve 55 is moved forward via the connecting member 70, and the engagement between the driving sleeve 55 and the gear sleeve 56 is released. Therefore, the transmission of torque to the tool holder 30 is blocked, and the rotation of the tool body 10 stops. Note that after rotating the second motor 4 in the second rotation direction, when the controller 9 obtains an on signal from the second switch 92 (that is, when the operation mode switches to the impact mode), the controller 9 stops driving the second motor 4.

[0085] In the present embodiment, when the acceleration is equal to or greater than the threshold value and the operation mode is the rotary impact mode, the controller 9 further stops driving the first motor 2. By doing so, the operation of the hammer drill 100 is completely stopped.

[0086] Note that in the present embodiment, when the detection result of the acceleration sensor 95 is equal to or greater than the threshold value but the controller 9 has not obtained an on signal from the first switch 91 (that is, when the operation mode is not the rotary impact mode), the controller 9 does not drive the second motor 4 and continues to drive the first motor 2. By doing so, for example, even when the detection result of the acceleration sensor 95 temporarily becomes equal to or greater than the threshold value due to the impact of the hammer drill 100 contacting a wall or the like near the workpiece during machining in the impact mode, the user can continue the machining operation in the impact mode.

[0087] Next, the lock mechanism 8 will be described with reference to FIGS. 9 to 11. In the present embodiment, the lock mechanism 8 includes a lock lever 180 and a first member 71.

[0088] The lock lever 180 is located at the upper end of the handle 17 (near the connecting portion 173), above the switch lever 171, and is supported so as to be movable in the left - right direction with respect to the handle 17. In the present embodiment, the lock lever 180 includes a rod - shaped main body portion 181 extending in the left - right direction and two locking pieces 182 protruding downward from the lower end portion of the main body portion 181. As shown in FIG. 9, both end portions of the main body portion 181 in the left - right direction are exposed from openings 177 provided in the left wall and the right wall of the connecting portion 173. The user can operate the lock lever 180 by pushing the main body portion 181 leftward or rightward with respect to the handle 17.

[0089] Two locking projections 178 protruding upward are provided on the switch lever 171 of the present embodiment. As shown by the solid line in FIG. 9, the two locking pieces 182 of the lock lever 180 are arranged at a distance from each other in the left - right direction so that the locking projections 178 of the switch lever 171 can be disposed between the two locking pieces 182. Note that, as shown by the dashed - double - dotted line in FIG. 9, the interval between the two locking pieces 182 of the lock lever 180 is equal to the interval between the two locking projections 178 of the switch lever 171.

[0090] The lock lever 180 is movable between a lockable position where it can lock the switch lever 171 in the on state and a non-lockable position where it cannot lock the switch lever 171 in the on state. The lockable position is the position of the lock lever 180 where the locking piece 182 of the lock lever 180 is on the movement path of the locking projection 178 of the switch lever 171, as shown by the two-dot chain line in FIG. 9. In the lockable position, the rear end of the locking piece 182 of the switch lever 171 abuts against the front end of the locking projection 178 of the switch lever 171 that has moved to the on position, so that the switch lever 171 can be held in the on position. The non-lockable position is the position of the lock lever 180 where the locking piece 182 of the lock lever 180 is out of the movement path of the locking projection 178 of the switch lever 171, as shown by the solid line in FIG. 9. In the non-lockable position, the locking projection 178 does not interfere with the movement of the locking piece 182 in the front-rear direction. Therefore, the switch lever 171 can move between the on position and the off position. Note that the lock lever 180 is always arranged in the non-lockable position shown by the solid line in FIG. 9 by the user in order to enable the operation of the switch lever 171, and is moved to the lockable position by the user only when locking the switch lever 171 in the on state. Although not shown in the figure, in this embodiment, the lock lever 180 is held in the non-lockable position or the lockable position by the biasing force of the biasing member.

[0091] Returning to the description of the lock lever 180. A lock hole 184 penetrating the main body 181 in the front-rear direction is formed at a substantially central portion of the main body 181 in the left-right direction. The height in the up-down direction and the width in the left-right direction of the lock hole 184 are formed to be the height and width into which the plate-like portion 711 of the first member 71 can be inserted. The first member 71 constitutes a part of the connecting member 70 as described above, and moves in the front-rear direction along the drive shaft A1 in response to the operation of the mode switching operation unit 6.

[0092] Figures 4, 6, and 8 show the positional relationship between the connecting member 70 and the locking hole 184. When the plate-like portion 711 of the first member 71 is moved to the rearmost position within the movement range (that is, when the rotary impact mode is selected), it engages with the locking hole 184, and when it is moved forward from the rearmost position (that is, when the neutral mode or the impact mode is selected), the engagement with the locking hole 184 is released, and it extends in the front-rear direction.

[0093] With the above configuration, when the switch 60d of the mode switching operation unit 6 is turned on (that is, when the rotary impact mode is selected), the connecting member 70 moves to the rearmost position within the movement range, and the plate-like portion 711 engages with the locking hole 184 (see FIGS. 6 and 11). Then, since the left-right movement of the lock lever 180 is restricted by the first member 71, the lock lever 180 remains in the non-lockable position. On the other hand, when the switch 60h of the mode switching operation unit 6 is turned on (that is, when the impact mode is selected), the connecting member 70 moves to the foremost position within the movement range, and the engagement between the plate-like portion 711 and the locking hole 184 is released (see FIGS. 4 and 9). Therefore, the lock lever 180 can move in the left-right direction. In this state, when the lock lever 180 is moved to the lockable position by the user's operation, the on state of the switch lever 171 is maintained. That is, in the impact mode, the user can continue the on state of the switch lever 171 without continuously pressing the switch lever 171 by pushing the lock lever 180 into the lockable position.

[0094] According to the hammer drill 100 of the present embodiment described above, the following effects can be obtained.

[0095] According to the hammer drill 100 of the present embodiment, the rotational motion of the second motor 4 is converted into linear motion by the transmission mechanism 7 and transmitted to the driving sleeve 55, and the driving sleeve 55 is moved parallel to the drive shaft A1, thereby enabling the switching of the operation mode. Further, when the tool body 10 is in a state of rotating excessively around the drive shaft A1, the hammer drill 100 is configured to drive the second motor 4 to move the driving sleeve 55 via the transmission mechanism 7, thereby blocking the transmission of torque to the tool holder 30. Therefore, when the tool body 10 is in a state of rotating excessively around the drive shaft A1, the rotation of the tool body 10 can be stopped. Thus, according to the present embodiment, it is possible to provide a highly safe hammer drill 100 capable of realizing the switching of the operation mode and the blocking of the torque transmission using the same second motor 4.

[0096] Further, the hammer drill 100 of the present embodiment includes a controller 9 and an acceleration sensor 95. The controller 9 is configured to drive the second motor 4 to block the torque transmission when the tool body 10 is in a state of rotating excessively around the drive shaft A1, using the detection result of the acceleration sensor 95, and in addition, to stop the drive of the first motor 2 which is the drive source of the tip tool 101. Therefore, the safety of the hammer drill 100 can be further improved.

[0097] Further, the second motor 4 is disposed on the drive shaft A1, and the rotation shaft A3 of the second motor 4 extends in a direction intersecting the drive shaft A1. Therefore, compared with a configuration in which the rotation shaft A3 of the second motor 4 is arranged parallel to the drive shaft A1 and the second motor 4 is arranged at a position deviated from the drive shaft A1, the second motor 4 can be arranged closer to the driving sleeve 55. Therefore, the transmission mechanism 7 can be configured compactly, and the hammer drill 100 can be configured to be small.

[0098] Further, the transmission mechanism 7 includes a pinion gear 42 as an output gear of the second motor 4, and a first member 71 formed with a rack gear 712 that engages with the pinion gear 42. Therefore, by converting the rotational motion of the second motor 4 into a linear motion parallel to the drive shaft A1 by the pinion gear 42 and the rack gear 712, the driving sleeve 55 can be moved back and forth. Also, the conversion from rotational motion to linear motion can be easily realized by the pinion gear 42 and the rack gear 712.

[0099] Also, the hammer drill 100 includes a mode detection unit 90 capable of detecting an operation mode. The mode detection unit 90 includes a first switch 91 and a second switch 92. The first switch 91 is configured to contact the first member 71 when the driving sleeve 55 moves to the position Pd, and the second switch 92 is configured to contact the first member 71 when the driving sleeve 55 moves to the position Ph. Therefore, according to the hammer drill 100 of the present embodiment, it is possible to determine from the detection result of the first switch 91 that the operation mode is the rotary impact mode. Also, it is possible to determine from the detection result of the second switch 92 that the operation mode is the impact mode.

[0100] In the present embodiment, even when the tool body 10 rotates excessively around the drive shaft A1, the controller 9 does not drive the second motor 4 or stop the first motor 2 when the operation mode is not the rotary impact mode. Therefore, for example, even when the detection result of the acceleration sensor 95 temporarily exceeds the threshold value due to an impact caused by the hammer drill 100 contacting a wall or the like near the workpiece during machining in the impact mode, the user can continue the machining operation in the impact mode. Therefore, it is possible to suppress the operation mode from being switched or the first motor 2 from stopping unintentionally by the user during the impact mode. Therefore, according to the present embodiment, it is possible to provide a hammer drill 100 with improved safety and operability.

[0101] In this embodiment, the controller 9 switches the operation mode by driving the second motor 4 to move the connection member 70, and is configured to stop the second motor 4 when an on signal is obtained from the first switch 91 or the second switch 92. Therefore, the timing of stopping the second motor 4 can be controlled using the mode detection unit 90.

[0102] Further, the hammer drill 100 includes a stopper 65 fixed to the gear housing 12. The stopper 65 is configured such that the front end face 66 interferes with the first member 71 to position the driving sleeve 55 at the position Pd, and the rear end face 67 interferes with the first member 71 to position the driving sleeve 55 at the position Ph. Therefore, the positioning accuracy of the driving sleeve 55 can be improved. Also, after the controller 9 stops the second motor 4 using the detection result of the mode detection unit 90, even if the second motor 4 rotates due to inertia, the movement of the first member 71 (connection member 70) can be restricted by the stopper 65. Therefore, compared with a configuration in which the hammer drill 100 does not include the stopper 65, it is possible to suppress an excessive load from being applied to the first switch 91 and the second switch 92 by the connection member 70. Accordingly, the first switch 91 and the second switch 92 can be made to have a longer service life.

[0103] The hammer drill 100 of the present embodiment is provided with a locking mechanism 8. When the tip tool 101 is in the percussion mode where it only performs a percussion operation, the first member 71 is configured not to engage with the lock lever 180 and to allow the lock lever 180 to move to a lockable position. Therefore, in a machining operation where the percussion operation alone is continuously performed for a relatively long time, the user does not have to continuously press the switch lever 171. Accordingly, the burden on the user in the machining operation can be reduced. Further, when the tip tool 101 is in the rotary percussion mode where it performs a rotary operation, the first member 71 is configured to engage with the lock lever 180 and hold the lock lever 180 in a non-lockable position. Therefore, for example, even if the tip tool 101 is locked to the workpiece, the user can stop the drive of the first motor 2 only by releasing the pressure on the switch lever 171. Accordingly, a highly safe hammer drill 100 can be provided.

[0104] Also, in the hammer drill 100, the acceleration sensor 95 is housed in the handle 17, and the tool body 10 and the handle 17 are connected via elastic members 175 and 176. Therefore, the vibration of the tool body 10 transmitted to the acceleration sensor 95 can be reduced, so that the acceleration sensor 95 can have a longer service life.

[0105] Furthermore, in the present embodiment, the acceleration sensor 95 is housed in the lower part of the handle 17. Therefore, the detection accuracy of the rotation around the drive shaft A1 of the tool body 10 can be improved as compared with the case where the acceleration sensor 95 is housed at a position close to the drive shaft A1, such as the upper part of the handle 17.

[0106] Further, the hammer drill 100 is configured to switch the operation mode via the transmission mechanism 7 by driving the second motor 4. Therefore, an operation unit (mode switching operation unit 6) for switching the operation mode can be configured by an electronic switch for outputting an on signal. Further, the mode switching operation unit 6 can be arranged without providing a gap between the mode switching operation unit 6 and the outer surface of the tool body 10. Therefore, the design property of the hammer drill 100 can be improved. Further, since dust or the like does not enter between the mode switching operation unit 6 and the tool body 10, the mode switching operation unit 6 can have a long service life.

[0107] In the present embodiment, the second motor 4 is configured not to be driven even if the mode switching operation unit 6 is operated during the driving of the first motor 2. Therefore, for example, even when an object or the like around the hammer drill 100 hits the mode switching operation unit 6 and the mode switching operation unit 6 is operated during the machining operation (when the first motor 2 is driven), the second motor 4 is not driven. Therefore, wear and breakage of the clutch mechanism 54 and the components constituting the hammer drill 100 due to the driving of the second motor 4 during the driving of the first motor 2 can be suppressed.

[0108] Furthermore, the hammer drill 100 includes a notification unit 61 that lights up corresponding to the selected operation mode. Therefore, even when the operation state of the switch cannot be determined only by visually recognizing the mode switching operation unit 6, the user can know the selected operation mode.

[0109] <Corresponding relationship> The corresponding relationship between each component of the above embodiment and each component of the technology of the present disclosure is shown below. However, each component of the embodiment is merely an example and does not limit each component of the technology of the present disclosure.

[0110] The hammer drill 100 is an example of a "rotary percussion tool". The tool body 10 is an example of a "tool body". The first motor 2 is an example of a "first motor". The tip tool 101 is an example of a "tip tool". The drive shaft A1 is an example of a "drive shaft". The drive mechanism 3 is an example of a "drive mechanism". The rotary impact mode is an example of a "first mode". The impact mode is an example of a "second mode". The tool holder 30 is an example of a "tool holder". The second motor 4 is an example of a "second motor". The transmission mechanism 7, the pinion gear 42, and the connecting member 70 are an example of a "transmission mechanism". The driving sleeve 55 is an example of a "clutch member". The positions Pd and Ph are examples of a "transmission position" and a "cut-off position", respectively. The acceleration sensor 95 is an example of a "rotation detection unit". The controller 9 and the CPU are an example of a "control unit". The mode detection unit 90 is an example of a "mode detection unit". The first switch 91 and the second switch 92 are examples of a "first detection unit" and a "second detection unit", respectively. The first member 71 is an example of a "first member". The stopper 65 is an example of a "stopper". The rear direction and the front direction are examples of a "first direction" and a "second direction", respectively. The front end face 66 and the rear end face 67 are examples of a "first face" and a "second face", respectively. The rotating shaft A3 is an example of a "rotating shaft of the second motor". The motor shaft 41 is an example of a "motor shaft". The pinion gear 42 and the rack gear 712 are examples of a "pinion gear" and a "rack gear", respectively. The switch lever 171 is an example of a "main operation member". The lock lever 180 is an example of a "lock member". The first member 71 is an example of a "lock control member". The gripping part 170 and the handle 17 are examples of a "gripping part" and a "handle", respectively. The elastic members 175 and 176 are an example of "elastic members". The mode switching operation unit 6 is an example of "mode switching operation unit". The notification unit 61 is an example of "notification unit".

[0111] <Other Embodiments> In the above embodiment, when the detection result of the acceleration sensor 95 is equal to or greater than the threshold value and the operation mode is the rotational impact mode, the controller 9 rotates the second motor 4 in the second rotational direction to cut off the torque transmission and stops the driving of the first motor 2. On the contrary, when the acceleration is equal to or greater than the threshold value and the operation mode is the rotational impact mode, the controller 9 may rotate the second motor 4 in the second rotational direction and continue to drive the first motor 2. That is, only the impact operation may be continued. Also in this form, since the torque transmission to the tool holder 30 is cut off, an excessive rotational state of the tool body 10 can be eliminated.

[0112] In the above embodiment, when the detection result of the acceleration sensor 95 is equal to or greater than the threshold value and the operation mode is the rotational impact mode, the controller 9 rotates the second motor 4 in the second rotational direction to cut off the torque transmission, and when an on signal of the second switch 92 is acquired (that is, when the operation mode is switched to the impact mode), the driving of the second motor 4 is stopped. On the contrary, the controller 9 may stop the driving of the second motor 4 even when the first switch 91 is turned off without acquiring the on signal of the second switch 92. That is, the controller 9 may stop the driving of the second motor 4 when the operation mode is switched to the neutral mode. Also in this form, since the torque transmission to the tool holder 30 is cut off, an excessive rotational state of the tool body 10 can be eliminated.

[0113] The mode switching operation unit 6 does not necessarily have to be a push-type electronic switch. For example, the mode switching operation unit 6 may be configured by a touch panel. Further, the mode switching operation unit 6 may be configured as a switch that allows a user to select an operation mode by moving a member, such as a lever-type switch or the like.

[0114] Instead of the LED lamps 61h, 61n, and 61d, the hammer drill 100 may be provided with a display device such as a liquid crystal panel or a speaker, and may be configured to notify the operation mode by displaying characters on the display device or outputting sound from the speaker.

[0115] In the above embodiment, the hammer drill 100 may be configured to operate with power supplied from a rechargeable battery instead of an external AC power supply. In this case, instead of the power cord 19, for example, a battery mounting portion where the battery can be detachably mounted may be provided at the lower end of the handle 17.

[0116] The mode detection unit 90 is not limited to a push-type micro switch, and may be configured by another detector that detects the position (movement) of the driving sleeve 55 (for example, a contact-type detector including other types of switches, a non-contact-type detector including a magnetic sensor and an optical sensor).

[0117] Instead of the acceleration sensor 95, the hammer drill 100 may be provided with another detection device capable of detecting the rotational state around the drive shaft A1 of the tool body 10. As another detection device, a speed sensor, an angular velocity sensor, or an angular acceleration sensor may be provided.

[0118] In the above-described embodiment, the hammer drill 100 was operable in a plurality of operation modes including a rotary impact mode and an impact mode. In contrast, the above embodiment may be applied to a rotary impact tool configured to perform, for example, a rotary impact mode, an impact mode, and a rotation mode. In this case, the drive control of the first motor 2 and the second motor 4 in the rotation mode is the same as that in the rotary impact mode.

[0119] The configuration of the transmission mechanism 7 only needs to be configured to move the driving sleeve 55 along the drive shaft A1 in response to the rotation of the second motor 4, and is not limited to the configuration of the above embodiment. Further, when the transmission mechanism 7 includes the connection member 70, the connection member 70 only needs to be configured to move parallel to the drive shaft A1 as the rack gear 712 moves, and the number and configuration of the components constituting the connection member 70 and the connection mode of each component are not limited to the above embodiment.

[0120] In the above embodiment, an example in which the drive control of the first motor 2 and the second motor 4 is executed by the CPU is given. However, instead of the CPU, other types of control circuits, for example, programmable logic devices such as ASIC (Application Specific Integrated Circuits) and FPGA (Field Programmable Gate Array) may be adopted. Further, the drive control process of the first motor 2 and the second motor 4 may be distributedly processed by a plurality of control circuits.

[0121] In the above embodiment, the driving sleeve 55 (clutch mechanism 54) is provided on the tool holder 30 and moves along the drive shaft A1, so as to move between the position Pd which is the torque transmission position to the tool holder 30 and the position Ph which cuts off the torque transmission. On the contrary, the clutch mechanism for performing the torque transmission to the tool holder 30 and the interruption of the torque transmission does not necessarily need to be provided on the tool holder 30. Further, the transmission mechanism 7 only needs to be configured to convert the rotational motion of the second motor 4 into a linear motion and transmit it to the clutch member, and may be movable in a direction different from the direction along the drive shaft A1.

[0122] The present disclosure is not limited to the above-described embodiments, and can be implemented in various configurations without departing from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the summary of the invention can be appropriately replaced or combined in order to solve some or all of the above-described problems or to achieve some or all of the above-described effects. Further, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

[0123] For example, in view of the technology of the present disclosure and the gist of the above-described embodiments, the following aspects are constructed. At least one of the following aspects can be adopted in combination with the above-described embodiments and their modifications and one or more of the technologies described in each claim. [Aspect 1] The rotary impact tool may include a control unit configured to be able to control the drive of the second motor. The control unit may be configured to drive the second motor to move the clutch member from the transmission position when the tool body is in a state of rotating excessively around the drive shaft. [Aspect 2] The rotary impact tool may include a mode switching operation unit configured to be manually operated by a user for selecting the operation mode of the drive mechanism, and a control unit configured to be able to control the drive of the second motor in response to an operation of the mode switching operation unit.

Explanation of Reference Numerals

[0124] 2... First motor 3... Drive mechanism 4... Second motor 6... Mode switching operation unit 7... Transmission mechanism 8... Lock mechanism 9... Controller 10... Tool body 12... Gear housing 13... Motor housing 17... Handle 19... Power cord 20... Motor main body 25... Motor shaft 29... Driving gear 30... Tool holder 31... Motion conversion mechanism 33... Impact mechanism 35... Rotation transmission mechanism 36... Intermediate shaft 40... Motor body 41... Motor shaft 42... Pinion gear 54... Clutch mechanism 55... Driving sleeve 56... Gear sleeve 60d, 60n, 60h... Switch 61... Notification part 61d, 61n, 61h... LED lamp 65... Stopper 66... Front end face 67... Rear end face 70... Connection member 71... First member 72... Second member 73... Third member 74... Engagement arm 76... Connecting pin 77... Torsion spring 90... Mode detection part 91... First switch 92... Second switch 95... Acceleration sensor 100... Hammer drill 101... Tip tool 122... Upper surface 123... Motor case 132... Rear wall 170... Gripping part 171... Switch lever 172... Main switch 173, 174... Connecting part 175, 176... Elastic members 177... Opening 178... Locking protrusion 180... Lock lever 181... Main body part 182... Locking piece 184... Lock hole 301... Lock ring 311... Crankshaft 312... Driven gear 313... Connecting rod 315... Piston 317... Cylinder 331... Striker 333... Impact bolt 335... Air chamber 361... Small bevel gear 362... Driven gear 551... Annular groove 561... Large bevel gear 711... Plate-like part 712... Rack gear 713... Right convex part 714... Left convex part 717... First convex part 718... Second convex part A1... Driving shaft A2... Rotation shaft A3... Rotation shaft Pd... Position Ph... Position

Claims

1. A rotary impact tool, comprising: a first motor and a second motor housed in a tool body; a drive mechanism selectively operable in a plurality of operation modes including a first mode in which an operation of rotationally driving a tip tool around a drive shaft is at least performed by the power of the first motor, and a second mode in which only an operation of linearly driving the tip tool along the drive shaft is performed; a tool holder configured to removably hold the tip tool; a clutch member provided on the tool holder and configured to be movable between a transmission position where torque is transmitted to the tool holder by the power of the second motor and is movable along the drive shaft, and a blocking position where transmission of torque to the tool holder is blocked; a transmission mechanism configured to convert a rotational motion of the second motor into a linear motion along the drive shaft and transmit the linear motion to the clutch member; an acceleration sensor configured to detect an acceleration around the drive shaft of the tool body; and comprising: the drive mechanism includes a motion conversion mechanism, an impact mechanism, and a rotation transmission mechanism; the motion conversion mechanism is configured to convert the rotation of the first motor into a linear motion and transmit the linear motion to the impact mechanism, and the impact mechanism is configured to impact the tip tool; the rotation transmission mechanism is configured to transmit the rotation of the first motor to the tool holder via the clutch member and rotate the tool holder around the drive shaft; the second motor: switches the operation mode of the drive mechanism to the first mode by moving the clutch member to the transmission position via the transmission mechanism, and switches the operation mode of the drive mechanism to the second mode by moving the clutch member to the blocking position; is configured to move the clutch member from the transmission position to the blocking position via the transmission mechanism when a detection result of the acceleration sensor is equal to or greater than a predetermined threshold at which a kickback phenomenon occurs in the tool body; a rotation axis of the second motor extends in a direction intersecting the drive shaft; the second motor is disposed on the drive shaft; a rotary impact tool.

2. The rotary impact tool according to claim 1, wherein: the transmission mechanism includes a pinion gear rotated by the second motor, and a rack gear engaged with the pinion gear and configured to convert the rotation of the pinion gear into the linear motion along the drive shaft.

3. A rotary impact tool, comprising: A first motor and a second motor housed in a tool body, A drive mechanism selectively operable in a plurality of operation modes including a first mode in which the tip tool is at least rotated around a drive shaft by the power of the first motor, and a second mode in which only an operation of linearly driving the tip tool along the drive shaft is performed; A tool holder configured to removably hold the tip tool; A clutch member provided on the tool holder and movable between a transmission position movable along the drive shaft by the power of the second motor and transmitting torque to the tool holder, and a blocking position for blocking transmission of torque to the tool holder; A transmission mechanism that converts the rotational motion of the second motor into a linear motion along the drive shaft and transmits it to the clutch member; An acceleration sensor for detecting an acceleration around the drive shaft of the tool body, The drive mechanism includes a motion conversion mechanism, a striking mechanism, and a rotation transmission mechanism, The motion conversion mechanism is configured to convert the rotation of the first motor into a linear motion and transmit it to the striking mechanism, and the striking mechanism is configured to strike the tip tool, The rotation transmission mechanism is configured to transmit the rotation of the first motor to the tool holder via the clutch member to rotate the tool holder around the drive shaft, The second motor, By moving the clutch member to the transmission position via the transmission mechanism, the operation mode of the drive mechanism is switched to the first mode, and by moving the clutch member to the blocking position, the operation mode of the drive mechanism is switched to the second mode, When the detection result of the acceleration sensor is equal to or greater than a predetermined threshold at which a kickback phenomenon occurs in the tool body, the clutch member is configured to be moved from the transmission position to the blocking position via the transmission mechanism, The transmission mechanism is operably connected to the second motor and the clutch member, and includes a first member moved along the drive shaft by the second motor, The tool body further includes a stopper configured to interfere with the first member to position the clutch member at the transmission position and to interfere with the first member to position the clutch member at the blocking position, A rotary impact tool.

4. The rotary impact tool according to claim 3, The first member is movable in a first direction parallel to the drive shaft and in a second direction opposite to the first direction. The stopper includes a first surface and a second surface that intersect the moving direction of the first member. The first surface positions the clutch member at the transmission position by interfering with the first member when the first member moves in the first direction, and the second surface positions the clutch member at the cutoff position by interfering with the first member when the first member moves in the second direction. A rotary impact tool.

5. A rotary impact tool according to any one of claims 1 to 4, comprising a control unit configured to be able to control the driving of the first motor and the second motor, wherein the control unit is configured to stop the first motor when the detection result of the acceleration sensor is equal to or greater than the threshold value, and to drive the second motor to move the clutch member from the transmission position to the cutoff position. A rotary impact tool.

6. A rotary impact tool according to any one of claims 1 to 5, comprising a first detection unit configured to detect that the operation mode of the drive mechanism is the first mode, and a second detection unit configured to detect that the operation mode of the drive mechanism is the second mode. A rotary impact tool comprising a mode detection unit.

7. A rotary impact tool according to claim 6, which depends on claim 5, wherein the control unit is configured to stop the second motor according to the detection result of the mode detection unit. A rotary impact tool.

8. A rotary impact tool according to any one of claims 1 to 7, a main operation member that is normally maintained at an off position and moves to an on position when pressed by a user to enable driving of the first motor; a lock member configured to be movable by a user's operation between a lockable position where the main operation member can be locked at the on position and a non-lockable position where the main operation member cannot be locked at the on position; a lock control member disposed at a position that interferes with the lock member in the first mode to maintain the lock member at the non-lockable position, and disposed at a position that does not interfere with the lock member in the second mode to allow the lock member to move to the lockable position. A rotary impact tool.

9. A rotary impact tool according to any one of claims 1 to 8, a handle having a gripping portion that extends in a direction intersecting the drive shaft and is gripped by a user; an elastic member that connects the handle to the tool body so as to be relatively movable in a direction along the drive shaft; and the acceleration sensor is housed in the handle, the rotary impact tool.

10. A rotary impact tool according to any one of claims 1 to 9, comprising a mode switching operation unit configured to be manually operated by a user for selecting the operation mode of the drive mechanism; the mode switching operation unit is configured as an electronic switch disposed without providing a gap between the outer surface of the tool body, the rotary impact tool.

11. A rotary impact tool according to claim 10, the second motor is configured not to be driven in response to an operation of the mode switching operation unit when the first motor is driven, the rotary impact tool.

12. A rotary impact tool according to any one of claims 1 to 11, comprising a notification unit configured to notify the operation mode of the drive mechanism, the rotary impact tool.

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