CN112757231A

CN112757231A - Hammer drill

Info

Publication number: CN112757231A
Application number: CN202010648056.3A
Authority: CN
Inventors: 吉兼圣展; 高野优祐
Original assignee: Makita Corp
Current assignee: Makita Corp
Priority date: 2019-10-21
Filing date: 2020-07-07
Publication date: 2021-05-07
Also published as: EP3812097B1; JP2021065958A; EP3812097A1; RU2020134129A; JP7465647B2

Abstract

The invention provides a hammer drill. A hammer drill (101) is provided with a main shaft, a motor, a1 st intermediate shaft (41), an impact mechanism (6), a2 nd intermediate shaft (42), and a rotation transmission mechanism (7). The motor shaft extends in a direction crossing the drive axis. The 1 st intermediate shaft (41) extends parallel to the drive axis. The impact mechanism (6) converts the rotational motion of the 1 st intermediate shaft (41) into a linear motion, and linearly drives the tip tool along the drive axis. The 2 nd intermediate shaft (42) extends parallel to the drive axis. The rotation transmission mechanism (7) transmits the rotation of the 2 nd intermediate shaft (42) to the main shaft, and drives the tip tool to rotate around the drive axis. The motor shaft rotates the 1 st intermediate shaft (41) through a driven bevel gear (414). The 1 st countershaft (41) rotates the 2 nd countershaft (42) via a drive gear (415) and a driven gear (424). Accordingly, the power transmission efficiency of the hammer drill having 2 intermediate shafts can be improved.

Description

Hammer drill

Technical Field

The present invention relates to a hammer drill (hammer drill) capable of performing an operation of linearly driving a tip tool and an operation of rotationally driving the tip tool.

Background

The hammer drill is configured to be capable of a hammer action of driving a tip tool mounted to a tool holder (tooler) linearly along a driving axis and a drill action of driving the tip tool to rotate about a driving shaft. Generally, a motion conversion mechanism that converts a rotational motion of an intermediate shaft into a linear motion is used for hammer operation, and a rotation transmission mechanism that transmits a torque to a tool holder through (via) the intermediate shaft is used for drill operation. For example, in the hammer drill disclosed in patent document 1, separate intermediate shafts are provided for the motion conversion mechanism and the rotation transmission mechanism.

[ Prior art documents ]

[ patent document ]

Patent document 1: european patent No. 2700477 Specification

Disclosure of Invention

[ problem to be solved by the invention ]

In the hammer drill of patent document 1, once the intermediate shaft of the rotation transmission mechanism decelerates and rotates the main shaft as the final output shaft (final output shaft), the main shaft accelerates and rotates the intermediate shaft of the motion conversion mechanism, and therefore, there is a possibility that the efficiency is lowered.

In view of the above, an object of the present invention is to provide a hammer drill having 2 countershafts, which can improve power transmission efficiency.

[ solution for solving problems ]

According to one aspect of the present invention, there is provided a hammer drill having a final output shaft, a motor, a1 st intermediate shaft, a1 st drive mechanism, a2 nd intermediate shaft, and a2 nd drive mechanism.

The final output shaft is configured to removably retain the tip tool. The final output shaft is arranged in a manner that it can rotate about its drive axis. The motor has a motor shaft extending in a direction intersecting the drive axis. The 1 st intermediate shaft extends parallel to the drive axis. The 1 st driving mechanism converts the rotational motion of the 1 st intermediate shaft into a linear motion, and is configured to be capable of performing a hammer action of driving a tip tool linearly along an axial line of the drive shaft. The 2 nd intermediate shaft extends parallel to the drive axis. The 2 nd drive mechanism transmits the rotation of the 2 nd intermediate shaft to the final output shaft, and is configured to be capable of performing a drilling operation. The drilling action is an action of driving the tip tool to rotate about the drive axis.

The motor shaft is configured to rotate one of the 1 st intermediate shaft and the 2 nd intermediate shaft via a pair of bevel gears (level gears). One of the 1 st and 2 nd countershafts is configured to rotate the other of the 1 st and 2 nd countershafts through a pair of gears.

In the hammer drill of this embodiment, the final output shaft, the 1 st intermediate shaft used by the 1 st driving mechanism that performs the hammer action, and the 2 nd intermediate shaft used by the 2 nd driving mechanism that performs the drill action extend in parallel with each other. On the other hand, the motor shaft extends in a direction crossing the final output shaft. The rotation of the motor shaft is first transmitted to one of the 1 st and 2 nd countershafts through a pair of bevel gears, and further transmitted to the other countershaft through a pair of gears. According to this configuration, since the final output shaft is not located on the transmission path between the 1 st intermediate shaft and the 2 nd intermediate shaft, power transmission can be efficiently performed without performing unnecessary speed reduction or speed increase.

In one aspect of the present invention, the motor shaft may be configured to rotate the 1 st intermediate shaft. The 1 st intermediate shaft may be configured to rotate the 2 nd intermediate shaft. This is a preferred embodiment because in this case the torque is transmitted directly from the motor shaft to the 1 st intermediate shaft which is subject to the load generated by the hammer action.

In one aspect of the present invention, the 1 st drive mechanism may include a motion conversion member disposed on the 1 st intermediate shaft and configured to convert rotational motion of the 1 st intermediate shaft into linear motion. One of the pair of bevel gears is provided on the 1 st intermediate shaft adjacent to a bearing that rotatably supports one end portion of the 1 st intermediate shaft. One of the pair of gears may be disposed between one of the pair of bevel gears and the motion conversion member on the 1 st intermediate shaft. In this case, the arrangement region of the bevel gears and the gears can be made compact in the axial direction of the 1 st intermediate shaft. Further, by intensively disposing the gears in the vicinity of the bearing with less deformation, the meshing between the pair of bevel gears and the meshing between the pair of gears can be maintained with high accuracy.

In one aspect of the present invention, the hammer drill may further include a torque limiter (torque limiter) that is disposed on the 2 nd intermediate shaft and configured to interrupt transmission when a torque acting on the 2 nd intermediate shaft exceeds a threshold value. By separately providing the 1 st intermediate shaft used for the 1 st driving mechanism performing the hammer action and the 2 nd intermediate shaft used for the 2 nd driving mechanism performing the drill action, a space is easily generated in the 2 nd intermediate shaft. Therefore, the space can be effectively utilized to achieve reasonable arrangement of the torque limiter.

In an aspect of the present invention, a rotational axis of one of the 1 st intermediate shaft and the 2 nd intermediate shaft and a rotational axis of the motor shaft may be located on the same plane. In this case, since these rotation axes do not become alternate axes, a bevel gear having a simple structure can be used. In this aspect, the drive axes are also preferably located on the same plane. In this case, the extending direction of the drive axis is defined as the forward and backward direction of the hammer drill, the direction orthogonal to the drive axis and corresponding to the extending direction of the motor shaft is defined as the vertical direction, the directions orthogonal to the forward and backward direction and the vertical direction are defined as the horizontal direction, the side where the tip tool is attached is defined as the front side in the forward and backward direction, and the side where the motor is disposed of the drive axis is defined as the lower side in the vertical direction.

In one aspect of the present invention, the hammer drill may further include a1 st clutch mechanism and a2 nd clutch mechanism. The 1 st clutch mechanism is provided on the 1 st intermediate shaft and transmits or cuts off power for operating the hammer. The 2 nd clutch mechanism is provided on the 2 nd intermediate shaft and configured to transmit or cut off power for performing a drill operation. In this case, the power for performing the hammer operation and the power for performing the drill operation can be cut off as needed by using the 1 st clutch mechanism and the 2 nd clutch mechanism.

In the present aspect, the hammer drill may further include an operation member for switching an operation mode of the hammer drill. The operation member may be configured to be manually operated by a user. The 1 st clutch mechanism and the 2 nd clutch mechanism may be configured to be switched between a power transmission state and a power cutoff state in response to an operation of the operating member. In this case, the user can operate the 1 st clutch mechanism and the 2 nd clutch mechanism by operating only a single operation member according to a desired operation to switch the operation mode.

Drawings

FIG. 1 is a cross-sectional view of a hammer drill.

Fig. 2 is a sectional view of II-II of fig. 1.

Fig. 3 is a cross-sectional view of III-III of fig. 2.

Fig. 4 is a cross-sectional view of IV-IV of fig. 2.

Fig. 5 is a partially enlarged view of fig. 1.

Fig. 6 is a view of the internal structure of the drive mechanism housing section as viewed from the direction of the rotation axis of the mode switching dial, and is an explanatory view of the mode switching mechanism when the hammer drill mode is selected.

Fig. 7 is an explanatory diagram of the mode switching mechanism when the hammer mode is selected.

Fig. 8 is an explanatory diagram of the mode switching mechanism when the drill mode is selected.

[ description of reference numerals ]

1, hammer drilling; 2: a motor; 5: a drive mechanism; 6: an impact mechanism; 7: a rotation transmission mechanism; 10: a main body case; 11: a drive mechanism housing section; 12: a motor housing part; 15: a handle; 16: a grip portion; 17: a controller housing section; 20: a main body portion; 25: a motor shaft; 31: a main shaft; 32: a tool holder; 33: a piston cylinder; 41: 1 st intermediate shaft; 42: a2 nd intermediate shaft; 43: a torque limiter (torque limiter); 61: a motion conversion member; 62: 1 st clutch mechanism; 63: clamping the component; 64: a1 st transmission member; 65: a piston; 67: a ram (striker); 68: knocking a bolt; 71: a2 nd clutch mechanism; 72: a2 nd transmission member; 73: a torque limiter; 74: a drive side member; 75: a driven-side member; 76: balls (ball); 77: a force application spring; 78: a drive gear; 79: a driven gear; 80: a mode switching mechanism; 81: a1 st switching member; 82: a2 nd switching member; 83: a1 st spring; 84: a2 nd spring; 88: a support shaft; 91: a tip tool; 101: a hammer drill; 111: a cylindrical (barrel) section; 113: a support wall; 161: a trigger switch (trigger); 162: a switch; 171: a controller; 173: a battery mounting portion; 251: a bearing; 255: a drive bevel gear; 316: a bearing; 411: a bearing; 412: a bearing; 414: a driven bevel gear; 415: a drive gear; 416: a spline (spline) portion; 421: a bearing; 422: a bearing; 423: a gear component; 424: a driven gear; 425: a spline section; 611: a rotating body; 614: a bearing; 616: a swinging member; 617: an arm portion; 631: a spline section; 641: a1 st spline section; 642: a2 nd spline section; 645: a groove; 721: a1 st spline section; 722: a2 nd spline section; 725: a groove; 742: a cam recess; 743: a spline section; 752: a cam protrusion; 800: a mode switching dial; 801: an operation section; 803: a1 st pin; 805: a2 nd pin; 813: the 1 st clamping part; 823: the 2 nd engaging part; 881: a retainer ring; a1: a drive axis; a2: a rotation axis; a3: a rotation axis; a4: a rotation axis; p: a reference plane; r: an axis of rotation.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, the hammer drill 101 is illustrated as an example of an impact tool. The hammer drill 101 is a hand-held electric tool used for machining operations such as a shaving operation and a drilling operation, and is configured to be capable of performing an operation of linearly driving the tip tool 91 along a predetermined drive axis a1 (hereinafter referred to as a hammer operation) and an operation of rotating the tip tool 91 about a drive axis a1 (hereinafter referred to as a drill operation).

First, a schematic configuration of the hammer drill 101 will be briefly described with reference to fig. 1. As shown in fig. 1, the outer contour of the hammer drill 101 is mainly formed by the main body case 10 and the handle 15 connected to the main body case 10.

The main body case 10 is a hollow body also called a tool main body or an outer shell case, and houses the spindle 31, the drive mechanism 5, the motor 2, and the like. The main shaft 31 is an elongated cylindrical member. The main shaft 31 has a tool holder 32 that detachably holds the tip tool 91 at one end portion in the axial direction thereof. The long axis of the spindle 31 defines a drive axis a1 of the tip tool 91.

In the present embodiment, the entire main body case 10 is formed in a substantially L shape in side view. The main body case 10 includes two parts, a drive mechanism housing portion 11 and a motor housing portion 12, the drive mechanism housing portion 11 housing the spindle 31 and the drive mechanism 5, and the motor housing portion 12 housing the motor 2. The drive mechanism housing 11 extends along a drive axis a 1. The tool holder 32 is disposed in one end portion of the drive mechanism housing portion 11 in the extending direction of the drive axis a1 (hereinafter, simply referred to as the drive axis direction). The motor housing portion 12 projects obliquely from the other end portion in the drive axis direction of the drive mechanism housing portion 11 in a direction away from the drive axis a 1. The motor 2 is disposed in the motor housing portion 12 such that the rotation axis a2 of the motor shaft 25 extends in a direction intersecting the drive axis a1 (specifically, in a direction inclined with respect to the drive axis a 1).

In the following description, for convenience, the extending direction of the drive axis a1 is defined as the front-rear direction of the hammer drill 101. In the front-rear direction, one end side on which the tool holder 32 is disposed is defined as a front side of the hammer drill 101, and the opposite side is defined as a rear side. A direction orthogonal to the drive axis a1, that is, a direction corresponding to the direction in which the rotation axis a2 of the motor shaft 25 extends, is defined as the vertical direction of the hammer drill 1. In the vertical direction, the direction in which the motor housing portion 12 protrudes from the drive mechanism housing portion 11 is defined as downward, and the opposite direction is defined as upward. The direction orthogonal to the front-rear direction and the up-down direction is defined as the left-right direction.

The handle 15 is formed in a substantially C-shape as a whole in a side view, and both end portions are connected to the main body case 10. The handle 15 includes an elongated cylindrical grip portion 16 and a rectangular box-shaped controller housing portion 17 connected to a lower side of the grip portion 16. The grip portion 16 is a portion gripped by the user, is disposed apart from the main body case 10 at the rear of the main body case 10, and extends substantially in the vertical direction so as to intersect with the drive axis a 1. A trigger switch 161 that can be pressed (pushed) by a user is provided at the front of the upper end of the grip portion 16. A switch 162 that is turned on in response to a pressing operation of the trigger switch 161 is disposed inside the grip portion 16. The controller storage portion 17 stores a controller 171 for controlling the driving of the motor 2. A battery mounting portion 173 is provided at a lower end portion of the controller housing portion 17, and a rechargeable battery (battery pack) 93 serving as a power source of the motor 2 and the like is attachable to and detachable from the battery mounting portion 173.

In the present embodiment, the handle 15 is elastically coupled to the main body case 10 so as to be movable relative to the main body case 10. Specifically, the lower end portion of the handle 15 is disposed in the lower end portion of the motor housing portion 12, and is supported so as to be rotatable about a rotation axis extending in the left-right direction. The upper end of the handle 15 is connected to the rear end of the drive mechanism housing 11 so as to be movable in the front-rear direction by an urging spring.

In the hammer drill 1, when the trigger switch 161 is operated to be turned on and the switch 162 is turned on, the motor 2 is energized by the controller 171 to perform a hammer operation and/or a drill operation.

Next, the detailed structure of the hammer drill 101 will be described.

First, the structure of the main body case 10 (the motor housing portion 12 and the drive mechanism housing portion 11) and the internal structure thereof will be described.

As shown in fig. 1, the motor housing portion 12 is a portion of the main body case 10 that is connected to the rear end portion of the drive mechanism housing portion 11 and extends downward. The motor housing portion 12 houses the motor 2. In the present embodiment, a dc brushless motor is used as the motor 2. The motor 2 has a main body portion 20 and a motor shaft 25, wherein the main body portion 20 includes a stator and a rotor; the motor shaft 25 is configured to rotate integrally with the rotor. Motor shaft 25 is supported by main body case 10 so as to be rotatable about rotation axis a2 by means of bearing 251 and bearing 252. The rotation axis a2 extends diagonally downward and forward with respect to the drive axis a 1. The upper end of motor shaft 25 protrudes into drive mechanism accommodating portion 11. A drive bevel gear 255 is fixed to the upper end of motor shaft 25.

As shown in fig. 1, the drive mechanism housing portion 11 is a portion of the main body case 10 that extends along the drive axis a1 and houses the spindle 31 and the drive mechanism 5. The drive mechanism housing portion 11 has a cylindrical distal end portion. This cylindrical portion is referred to as a cylindrical portion 111. The drive mechanism housing portion 11 is formed in a substantially rectangular box shape except for the cylindrical portion 111. An assist grip (not shown) can be attached to the cylindrical portion 111. The user can also grip an auxiliary handle attached to the cylindrical portion 111 in an auxiliary manner in addition to the handle 15.

The main shaft 31 is the final output shaft of the hammer drill 101. The main shaft 31 is supported by the main body case 10 so as to be rotatable about a drive axis a1 by a bearing 316 and a bearing 317. The front half of the spindle 31 constitutes a tool holder 32 to which the tip tool 91 can be attached and detached. The tip tool 91 is inserted into the tool holder 32 in such a manner that the long axis thereof coincides with the drive axis a1, and the tip tool 91 is held in a state that allows it to move in the axial direction relative to the tool holder 32 and restricts its rotation about the axis. The rear half of the main shaft 31 constitutes a piston cylinder 33 slidably holding a piston 65 described later. In the present embodiment, the spindle 31 is a single member in which the tool holder 32 and the piston cylinder 33 are integrally formed, but may be formed by connecting a plurality of members.

The drive mechanism 5 includes an impact mechanism 6 and a rotation transmission mechanism 7 (see fig. 3), wherein the impact mechanism 6 is configured to perform a hammer operation; the rotation transmission mechanism 7 is configured to perform a drilling operation. In the present embodiment, the power of the motor 2 is transmitted to the impact mechanism 6 via the 1 st intermediate shaft 41, and is transmitted to the rotation transmission mechanism 7 via the 2 nd intermediate shaft 42. That is, the hammer drill 101 has two separate intermediate shafts for the impact mechanism 6 and the rotation transmission mechanism 7.

Here, the arrangement of 1 st

intermediate shaft

41 and 2 nd intermediate shaft 42 will be described.

As shown in fig. 1 to 4, both the 1 st intermediate shaft 41 and the 2 nd intermediate shaft 42 extend parallel to the drive axis a1 in the drive mechanism accommodating portion 11. As shown in fig. 3, the 1 st intermediate shaft 41 is supported by the main body case 10 so as to be rotatable about the rotation axis a3 by two bearings, i.e., a bearing 411 and a bearing 412. Similarly, the 2 nd intermediate shaft 42 is supported by the main body case 10 so as to be rotatable about the rotation axis a4 by two bearings, i.e., a bearing 421 and a bearing 422.

As shown in fig. 2, in the present embodiment, the rotation axis A3 of the 1 st countershaft 41 extends parallel to the drive axis a1 directly below the drive axis a 1. The rotation axis A3, the drive axis a1, and the rotation axis a2 of the motor shaft 25 are all located on the same plane (hereinafter, referred to as a reference plane P). The reference plane P extends in the vertical direction of the hammer drill 101. On the other hand, the rotation axis a4 of the 2 nd intermediate shaft 42 is located on the left side with respect to the reference plane P.

As shown in fig. 3 and 5, a driven bevel gear 414 is fixed to the rear end portion of the 1 st intermediate shaft 41 so as to be adjacent to the front side of the bearing 412. The driven bevel gear 414 is engaged with the driving bevel gear 255 of the motor shaft 25. Accordingly, the rotation of the motor shaft 25 is transmitted to the 1 st intermediate shaft 41 through the driving bevel gear 255 and the driven bevel gear 414.

In the present embodiment, the rotation axis A3 of the 1 st intermediate shaft 41 and the rotation axis a2 of the motor shaft 25 are both located on the reference plane P and intersect each other. In more detail, the rotation axis a2 and the rotation axis A3 intersect at an acute angle. Therefore, in the present embodiment, a straight bevel gear (straight bevel gear) having a simple structure and a low cost is used as the drive bevel gear 255 and the driven bevel gear 414. However, other types of crossed-axis gears (e.g., Spiral bevel gears) may be used. The drive bevel gear 255 and the driven bevel gear 414 constitute a reduction gear mechanism.

As shown in fig. 3, a drive gear 415 is fixed to the rear end portion of the 1 st intermediate shaft 41 so as to be adjacent to the front side of the driven bevel gear 414. On the other hand, a gear member 423 having a driven gear 424 is disposed at the rear end portion of the 2 nd intermediate shaft 42 so as to be adjacent to the front side of the bearing 422. The driven gear 424 meshes with the drive gear 415. Accordingly, the rotation of the 1 st intermediate shaft 41 is transmitted to the gear member 423 through the drive gear 415 and the driven gear 424. Further, in the present embodiment, the drive gear 415 and the driven gear 424 have the same diameter. Further, spur gears (spur gears) having a simple structure and a low price are used as the drive gear 415 and the driven gear 424. However, other types of parallel axis gears (e.g., helical gears) may be used.

The gear member 423 is formed in a cylindrical shape and is disposed on the outer peripheral side of the 2 nd intermediate shaft 42 (to be more specific, a drive-side member 74 described later). Further, a spline portion 425 is provided on the outer periphery of the cylindrical front end portion of the gear member 423. The spline portion 425 has a plurality of splines (external teeth) extending in the direction of the rotation axis a4 (front-rear direction). The rotation of the gear member 423 is transmitted to the 2 nd intermediate shaft 42 via the 2 nd transmitting member 72 and the torque limiter 73, which will be described later.

Next, the detailed structure of the impact mechanism 6 and the rotation transmission mechanism 7 will be described in order.

The impact mechanism 6 is a mechanism for performing a hammer operation, and is configured to convert the rotational motion of the 1 st intermediate shaft 41 into a linear motion and linearly drive the tip tool 91 along the drive axis a 1. In the present embodiment, as shown in fig. 1 and 5, the impact mechanism 6 includes a motion conversion member 61, a piston 65, a hammer 67, and a striker 68.

The motion conversion member 61 is disposed on the 1 st intermediate shaft 41, and is configured to convert the rotational motion of the 1 st intermediate shaft 41 into linear motion and transmit the linear motion to the piston 65. In more detail, the motion converting part 61 includes a rotating body 611 and a swinging part 616.

The rotating body 611 is supported by the main body case 10 via a bearing 614 so as to be rotatable about the rotation axis a 3. In the present embodiment, a cylindrical clamping member 63 is clamped between the rotating body 611 and the 1 st intermediate shaft 41. The sandwiching member 63 is configured to be immovable in the front-rear direction with respect to the 1 st intermediate shaft 41 and to be rotatable with respect to the 1 st intermediate shaft 41 integrally with the rotating body 611. The front end of the clamping member 63 protrudes forward from the front end of the rotating body 611. The swinging member 616 is rotatably attached to the outer periphery of the rotating body 611, and is configured to swing in the extending direction (front-rear direction) of the rotation axis a3 in accordance with the rotation of the rotating body 611. The swinging member 616 has an arm portion 617 extending upward from the rotating body 611.

The piston 65 is a bottomed cylindrical member, and is disposed in the piston cylinder 33 of the main shaft 31 so as to be slidable along the drive axis a 1. The piston 65 is coupled to the arm portion 617 of the swinging member 616 by a coupling pin, and reciprocates in the front-rear direction in accordance with the swinging of the swinging member 616.

The hammer 67 is an impact member for applying an impact force to the tip tool 91. The hammer 67 is disposed in the piston 65 so as to be slidable along the drive axis a 1. The internal space of the piston 65 on the rear side of the ram 67 is defined as an air chamber functioning as an air spring. The striker 68 is an intermediate member that transmits the kinetic energy of the hammer 67 to the tip tool 91. The striker 68 is disposed on the front side of the hammer 67 in the tool holder 32 so as to be movable along the drive axis a 1.

When the piston 65 moves in the front-rear direction in accordance with the swing of the swing member 616, the pressure of the air in the air chamber fluctuates, and the ram 67 slides in the front-rear direction in the piston 65 by the action of the air spring. More specifically, when the piston 65 moves forward, air in the air chamber is compressed to increase the internal pressure. The striker 67 is pushed forward at high speed by the air spring and impacts the striker 68. The striker 68 transmits the kinetic energy of the hammer 67 to the tip tool 91. Accordingly, the tip tool 91 is linearly driven along the drive axis a 1. On the other hand, when the piston 65 moves backward, the air in the air chamber expands to lower the internal pressure, and the hammer 67 is pulled backward. The tip tool 91 moves rearward together with the striker 68 by pressing the workpiece. In this way, the hammer operation is repeated by the impact mechanism 6.

In the present embodiment, the rotation of the 1 st intermediate shaft 41 is transmitted to the motion conversion member 61 (specifically, the rotating body 611) via the 1 st transmission member 64 and the sandwiching member 63.

The 1 st transmission member 64 is disposed on the 1 st intermediate shaft 41, is rotatable integrally with the 1 st intermediate shaft 41, and is movable in the direction of the rotation axis a3 (the front-rear direction) with respect to the 1 st intermediate shaft 41 and the sandwiching member 63. More specifically, a1 st spline portion 641 and a2 nd spline portion 642 are provided on the inner periphery of the 1 st transmission member 64, and the 1 st spline portion 641 can be engaged with the sandwiching member 63; the 2 nd spline portion 642 is always engaged with the 1 st intermediate shaft 41.

The 1 st spline portion 641 is provided on the inner periphery of the rear end portion of the 1 st transmission member 64. The 1 st spline portion 641 has a plurality of splines (internal teeth) extending in the direction of the rotation axis a3 (front-rear direction). On the other hand, a spline portion 631 is provided on the outer periphery of the distal end portion of the sandwiching member 63. Spline portion 631 has a plurality of splines (external teeth) that can engage with 1 st spline portion 641.

The 2 nd spline portion 642 is provided on the inner periphery of the front half of the 1 st transmission member 64. The 2 nd spline portion 642 has a plurality of splines (internal teeth) extending in the direction of the rotation axis a3 (front-rear direction). On the other hand, the front end portion of the 1 st intermediate shaft 41 (the portion adjacent to the rear side of the front bearing 411) is configured as a large diameter portion. A spline portion 416 is provided on the outer periphery of the large diameter portion. The spline portion 416 has a plurality of splines (external teeth) that are always engaged with the 2 nd spline portion 642.

According to such a configuration, as shown by a solid line in fig. 5, when the 1 st spline portion 641 is disposed at a position (hereinafter, referred to as an engagement position) where it engages with the spline portion 631 of the interposed member 63 in the front-rear direction, the 1 st transmission member 64 can rotate integrally with the interposed member 63 and the rotating body 611, that is, can transmit power from the 1 st intermediate shaft 41 to the motion converting member 61. On the other hand, as shown by the broken line in fig. 5, when the 1 st spline portion 641 is disposed at a position (hereinafter referred to as a separation position) where it is separated from (not engaged with) the spline portion 631, the 1 st transmission member 64 cannot transmit power (block power transmission) from the 1 st intermediate shaft 41 to the motion conversion member 61.

As described above, in the present embodiment, the 1 st transmission member 64 and the sandwiching member 63 function as the 1 st clutch mechanism 62 that transmits or blocks the power for operating the hammer. In the present embodiment, the 1 st transmission member 64 is connected to the mode switching mechanism 80 (see fig. 6), and moves between the engagement position and the disengagement position in response to an operation of the mode switching dial 800 (see fig. 2 and 4) by a user. That is, the 1 st clutch mechanism 62 switches between the power transmission state and the cut-off state in response to the operation of the mode switching dial 800. The mode switching mechanism 80 will be described in detail later.

The rotation transmission mechanism 7 is a mechanism for performing a drilling operation, and is configured to transmit the rotation of the 2 nd intermediate shaft 42 to the main shaft 31, thereby driving the tip tool 91 to rotate about the drive axis a 1. As shown in fig. 4, in the present embodiment, the rotation transmission mechanism 7 includes a drive gear 78 and a driven gear 79. The drive gear 78 is fixed to a front end portion (a portion adjacent to the rear side of the front bearing 421) of the 2 nd intermediate shaft 42. The driven gear 79 is fixed to the outer periphery of the piston cylinder 33 of the main shaft 31 and meshes with the drive gear 78. The drive gear 78 and the driven gear 79 constitute a gear reduction mechanism. As the drive gear 78 and the 2 nd intermediate shaft 42 rotate integrally, the main shaft 31 and the driven gear 79 rotate integrally. Accordingly, the drilling operation for driving the tip end tool 91 held by the tool holder 32 to rotate about the driving axis a1 is performed.

As described above, in the present embodiment, the rotation of the driven gear 424 that rotates with the rotation of the motor shaft 25 is transmitted to the 2 nd intermediate shaft 42 via the 2 nd transmission member 72 and the torque limiter 73. Hereinafter, the torque limiter 73 and the 2 nd transmitting member 72 will be described in order.

As shown in fig. 3 and 4, the torque limiter 73 is a safety clutch mechanism that is disposed on the 2 nd countershaft 42 and is configured to cut off transmission when the torque acting on the 2 nd countershaft 42 exceeds a threshold value. In the present embodiment, the torque limiter 73 includes a driving-side member 74, a driven-side member 75, balls 76, and an urging spring 77.

The drive side member 74 is a cylindrical member, and is rotatably supported by the rear half of the 2 nd intermediate shaft 42. The driven gear 424 is rotatably supported by the rear end portion of the driving side member 74. Accordingly, the driving-side member 74 is rotatable about the rotation axis a4 with respect to the 2 nd intermediate shaft 42 and the driven gear 424.

The drive side member 74 includes a cam recess 742 (refer to fig. 4) and a spline portion 743. The cam recess 742 is provided at the front end of the drive-side member 74. Although not shown in detail, the cam recess 742 has a cam surface inclined in the circumferential direction. The spline portion 743 is provided on the outer periphery of the drive-side member 74 on the rear side of the cam recess 742, and has a plurality of splines (external teeth) extending in the direction of the rotation axis a4 (the front-rear direction).

Driven-side member 75 is a cylindrical member, and is disposed around 2 nd intermediate shaft 42 on the front side of driving-side member 74. A plurality of grooves extending in the direction of the rotation axis a4 (front-rear direction) are provided in the circumferential direction on the inner periphery of the driven member 75. Further, a plurality of grooves extending in the direction of the rotation axis line a4 (front-rear direction) are provided in the circumferential direction on the outer periphery of the 2 nd intermediate shaft 42. The balls 76 are rollably housed in the tracks defined by these grooves. Accordingly, the driven-side member 75 is engaged with the 2 nd intermediate shaft 42 via the balls 76 in the radial direction and the circumferential direction, and is rotatable integrally with the 2 nd intermediate shaft 42. Further, the driven-side member 75 is movable in the front-rear direction with respect to the 2 nd intermediate shaft 42 within a range in which the balls 76 can roll in the track.

The driven-side member 75 has a cam protrusion 752 provided at the rear end (see fig. 4). Although not shown in detail, the cam protrusion 752 has a shape substantially matching the cam recess 742 of the drive-side member 74, and has a cam surface inclined in the circumferential direction. The biasing spring 77 is a coil compression spring, and is disposed in a compressed state between the drive gear 78 and the driven-side member 75. Therefore, the biasing spring 77 always biases the driven member 75 in a direction approaching the driving member 74, that is, in a direction (rearward) in which the cam protrusion 752 and the cam recess 742 are engaged with each other. When the cam protrusion 752 and the cam recess 742 are engaged with each other, torque can be transmitted from the driving-side member 74 to the driven-side member 75, and the 2 nd intermediate shaft 42 can be rotated. Further, the driving-side member 74 and the gear member 423 are biased rearward by the driven-side member 75, and are held in the rearmost position with respect to the 2 nd intermediate shaft 42.

Although not shown in detail, when a load equal to or greater than a threshold value is applied to the 2 nd intermediate shaft 42 by the tool holder 32 (main shaft 31) due to, for example, the locking of the tip end tool 91 during rotation of the 2 nd intermediate shaft 42, the meshing engagement between the cam protrusion 752 and the cam recess 742 is released. More specifically, the cam protrusion 752 and the cam recess 742 are separated from each other against the biasing force of the biasing spring 77 by the action of the cam surface (inclined surface) of the cam protrusion 752 and the cam recess 742, and moved to the distal end surface of the driving-side member 74. That is, the driven-side member 75 moves in the direction (forward) away from the driving-side member 74. At this time, the driven member 75 is guided by the balls 76 rolling between the driven member and the 2 nd intermediate shaft 42, and can move forward smoothly. As a result, the transmission of torque from drive-side member 74 to driven-side member 75 is interrupted, and the rotation of 2 nd intermediate shaft 42 is interrupted.

As shown in fig. 3 and 4, the 2 nd transmission member 72 is disposed on the 2 nd intermediate shaft 42, is rotatable integrally with the drive-side member 74 of the torque limiter 73, and is movable in the direction of the rotation axis line a4 (front-rear direction) with respect to the drive-side member 74 and the gear member 423.

More specifically, the 2 nd transmission member 72 is a substantially cylindrical member disposed around the drive side member 74, and the 1 st spline portion 721 and the 2 nd spline portion 722 are provided on the inner periphery of the 2 nd transmission member 72. The 1 st spline portion 721 is provided at the front half portion of the 2 nd transmission member 72. The 1 st spline portion 721 has a plurality of splines (internal teeth) that are constantly engaged with the spline portions 743 of the drive side member 74. The 2 nd spline portion 722 is provided at the rear end portion of the 2 nd transmission member 72. The 2 nd spline portion 722 has a plurality of splines (internal teeth) that can engage with the spline portion 425 of the gear member 423.

According to such a configuration, as shown by the solid line in fig. 4, when the 2 nd spline portion 722 is disposed at a position (hereinafter, referred to as an engagement position) where it engages with the spline portion 425 of the gear member 423 in the front-rear direction, the 2 nd transmission member 72 can rotate integrally with the gear member 423. Accordingly, the driving-side member 74 spline-engaged with the 2 nd transmission member 72 can also rotate integrally with the gear member 423. That is, in the engagement position, the 2 nd transmission member 72 can transmit the power from the gear member 423 to the 2 nd intermediate shaft 42 via the torque limiter 73. On the other hand, as shown by the broken line in fig. 4, when the 2 nd spline portion 722 is disposed at a position (hereinafter referred to as a separation position) where it is separated from (not engaged with) the spline portion 425, the 2 nd transmission member 72 cannot perform power transmission (power transmission interruption) from the gear member 423 to the 2 nd intermediate shaft 42.

As described above, in the present embodiment, the 2 nd transmission member 72 and the gear member 423 function as the 2 nd clutch mechanism 71 that transmits or cuts off the power for performing the drill operation. In the present embodiment, the 2 nd transmission member 72 is connected to the mode switching mechanism 80 (see fig. 6) as with the 1 st transmission member 64, and moves between the engagement position and the disengagement position in response to an operation of the mode switching dial 800 (see fig. 2) by the user. That is, like the 1 st clutch mechanism 62, the 2 nd clutch mechanism 71 is also switched between the power transmission state and the cut-off state in response to the operation of the mode switching dial 800.

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

As shown in fig. 6 to 8, the mode switching mechanism 80 is configured to switch the operation mode of the hammer drill 101 in conjunction with the mode switching dial 800. In the present embodiment, the hammer drill 101 has three operation modes, i.e., a hammer drill mode, a hammer mode, and a drill mode. The hammer drill mode is an operation mode in which both the impact mechanism 6 and the rotation transmission mechanism 7 are driven to perform a hammer operation and a drill operation. The hammer mode is an operation mode in which only the hammer operation is performed by cutting off the power transmission for performing the drill operation by the 2 nd clutch mechanism 71 and driving only the impact mechanism 6. The drill mode is an operation mode in which only the drill operation is performed by cutting off the power transmission for performing the hammer operation by the 1 st clutch mechanism 62 and driving only the rotation transmission mechanism 7.

As shown in fig. 2, 4, and 6, the mode switching dial 800 is provided on the left side portion of the main body case 10 (specifically, the drive mechanism housing portion 11) so as to be operable by a user from the outside. The mode switching dial 800 includes a disk-shaped operation portion 801 having a grip portion, and a1 st pin 803 and a2 nd pin 805 protruding from the operation portion 801.

The operation portion 801 is rotatably held by the main body case 10 about a rotation axis R (see fig. 6). A part of the operation portion 801 is partially exposed to the outside through an opening formed in the left side wall of the main body case 10 (the drive mechanism housing portion 11), and can be rotated by a user. Further, the mode switching dial 800 is provided with rotational positions corresponding to the hammer drill mode, the hammer mode, and the drill mode, respectively. The user can set the operation mode by placing the mode switching dial 800 at a rotational position corresponding to a desired operation mode. The 1 st pin 803 and the 2 nd pin 805 protrude from the inner surface of the operation portion 801 in the inner direction of the main body case 10. The 1 st pin 803 and the 2 nd pin 805 move on a circle centered on the rotation axis R of the operation portion 801 along with the rotation of the mode switching dial 800.

The mode switching mechanism 80 includes a1 st switching member 81, a2 nd switching member 82, a1 st spring 83, and a2 nd spring 84.

The 1 st switching member 81 has a pair of support holes (not shown), and is supported by a support shaft 88 inserted through the support holes so as to be movable in the front-rear direction. The support shaft 88 is a shaft that is supported by the main body case 10 (specifically, by a support wall 113 fixed inside the drive mechanism housing portion 11) and extends in the front-rear direction. The support shaft 88 extends parallel to the 1 st intermediate shaft 41 and the 2 nd intermediate shaft 42. A retainer ring 881 is fixed to a central portion of the support shaft 88 in the axial direction. The 1 st switching member 81 is supported on the front side of the retainer 881. The 2 nd switching member 82 has a pair of support holes (not shown), and is supported on the rear side of the retainer 881 so as to be movable in the front-rear direction by the support shaft 88 inserted through the support holes.

The 1 st switching member 81 and the 2 nd switching member 82 engage with the 1 st transmission member 64 and the 2 nd transmission member 72, respectively. More specifically, the 1 st transmission member 64 and the 2 nd transmission member 72 are provided with

annular grooves

645 and 725 on the outer peripheries thereof, respectively. The 1 st switching member 81 is engaged with the 1 st transmission member 64 by a plate-like 1 st engaging portion 813 (see fig. 8) disposed in the groove 645. Similarly, the 2 nd switching member 82 is engaged with the 2 nd transmission member 72 by a plate-like 2 nd engaging portion 823 (see fig. 5) disposed in the groove 725. The 1 st transmission member 64 is rotatable with respect to the 1 st switching member 81 in a state where the 1 st engagement portion 813 is engaged with the groove 645, and the 2 nd transmission member 72 is rotatable with respect to the 2 nd switching member 82 in a state where the 2 nd engagement portion 823 is engaged with the groove 725.

The 1 st spring 83 is a compression coil spring (compression coil spring), is disposed in a compressed state between the drive mechanism housing portion 11 and the 1 st switching member 81, and constantly biases the 1 st switching member 81 rearward. Accordingly, the 1 st transmission member 64 engaged with the 1 st switching member 81 is also always biased to the rearward engagement position. The 2 nd spring 84 is a coil compression spring, is disposed in a compressed state between the retainer 881 fixed to the support shaft 88 and the 2 nd switching member 82, and constantly biases the 2 nd switching member 82 rearward. Accordingly, the 2 nd transmission member 72 engaged with the 2 nd switching member 82 is also always biased to the rearward engagement position. The rearmost position of the 1 st switching member 81 is a position where the 1 st switching member 81 abuts against the stopper 881. The rearmost position of the 2 nd switching member 82 is a position where the 2 nd switching member 82 abuts on the front surface of the support wall 113.

When the mode switching dial 800 is disposed at a rotational position corresponding to the hammer drill mode (hereinafter referred to as a hammer drill position) shown in fig. 6, the 1 st pin 803 is disposed at a position adjacent to the rear of the 1 st switching member 81 disposed at the rearmost position, and the 2 nd pin 805 is disposed at a position adjacent to the rear of the 2 nd switching member 82 disposed at the rearmost position. At this time, the 1 st transmission member 64 is disposed at an engagement position (see fig. 5) where the 2 nd spline portion 642 engages with the spline portion 631 of the sandwiching member 63, and the 1 st clutch mechanism 62 is in a power transmission state. The 2 nd transmission member 72 is disposed at an engagement position (see fig. 4) where the 2 nd spline portion 722 engages with the spline portion 425 of the gear member 423, and the 2 nd clutch mechanism 71 is also in a power transmission state.

When the motor 2 is energized, power is transmitted from the motor shaft 25 to the 1 st intermediate shaft 41 through the driving bevel gear 255 and the driven bevel gear 414. Then, the power is transmitted from the 1 st intermediate shaft 41 to the impact mechanism 6 through the 1 st clutch mechanism 62, and the hammer operation is performed. Meanwhile, power is transmitted from the 1 st countershaft 41 to the 2 nd countershaft 42 through the drive gear 415 and the driven gear 424 and further through the 2 nd clutch mechanism 71 and the torque limiter 73. Then, the power is transmitted from the 2 nd intermediate shaft 42 to the main shaft 31 through the rotation transmission mechanism 7, and the drill operation is also performed.

When the mode switching dial 800 is operated to rotate from the hammer drill position shown in fig. 6 to the rotational position corresponding to the hammer mode (hereinafter, referred to as a hammer position) shown in fig. 7, the 2 nd pin 805 moves in the clockwise direction while coming into contact with the 2 nd switching member 82 from behind, and moves the 2 nd switching member 82 forward against the biasing force of the 2 nd spring 84. When the mode switching dial 800 is disposed at the hammer position, the 2 nd switching member 82 is disposed at the foremost position. The 2 nd transmission member 72 moves from the engagement position to the disengagement position (see fig. 4) in accordance with the movement of the 2 nd switching member 82, and the 2 nd clutch mechanism 71 is switched to the disengaged state.

On the other hand, the 1 st pin 803 is moved clockwise in a bottom view and is disposed at a position separated from the 1 st switching member 81 and the 2 nd switching member 82 when it does not interfere with the 1 st switching member 81 and the 2 nd switching member 82. Accordingly, during this time, the 1 st switching member 81 and the 1 st transmitting member 64 do not move, and the 1 st clutch mechanism 62 is maintained in the power transmission maintaining state.

Since power is not transmitted from motor shaft 25 to 2 nd intermediate shaft 42 even if motor 2 is energized, the drilling operation is not performed. On the other hand, since power is transmitted from the motor shaft 25 to the impact mechanism 6 through the 1 st intermediate shaft 41, only the hammer operation is performed.

When the mode switching dial 800 is operated to rotate from the hammer drill position shown in fig. 6 to the rotational position corresponding to the drill mode (hereinafter, referred to as a drill position) shown in fig. 8, the 1 st pin 803 comes into contact with the 1 st switching member 81 from behind, and moves counterclockwise about the rotational axis R of the operation portion 801 in a bottom view, and moves the 1 st switching member 81 forward against the biasing force of the 1 st spring 83. When the mode switching dial 800 is disposed at the drill position, the 1 st switching member 81 is disposed at the foremost position. The 1 st transmission member 64 moves from the engagement position to the disengagement position (see fig. 5) in accordance with the movement of the 1 st switching member 81, and the 1 st clutch mechanism 62 is switched to the disengaged state.

On the other hand, when the 2 nd pin 805 does not interfere with either the 1 st switching member 81 or the 2 nd switching member 82, it moves counterclockwise about the rotation axis R of the operation portion 801 in a bottom view and is disposed adjacent to the 2 nd switching member 82. Accordingly, during this period, the 2 nd switching member 82 and the 2 nd transmitting member 72 do not move, and the 2 nd clutch mechanism 71 is maintained in the power transmission maintaining state.

Since power is not transmitted from the 1 st intermediate shaft 41 to the motion conversion member 61 even if the motor 2 is energized, the hammer operation is not performed. On the other hand, since power is transmitted from motor shaft 25 to rotation transmission mechanism 7 through 2 nd intermediate shaft 42, only the drill operation is performed.

As described above, in the hammer drill 101 of the present embodiment, the main shaft 31, the 1 st intermediate shaft 41 used for the impact mechanism 6 that performs the hammer operation, and the 2 nd intermediate shaft 42 used for the rotation transmission mechanism that performs the drill operation extend parallel to each other. On the other hand, the motor shaft 25 extends in a direction crossing the main shaft 31. The rotation of motor shaft 25 is first transmitted to 1 st countershaft 41 via drive bevel gear 255 and driven bevel gear 414, and is also transmitted to 2 nd countershaft 42 via drive gear 415 and driven gear 424. That is, main shaft 31 is not located on the transmission path between 1

st countershaft

41 and 2 nd countershaft 42. Accordingly, unlike the case where rotation is transmitted from the 2 nd intermediate shaft 42 to the 1 st intermediate shaft 41 through the main shaft 31, no speed reduction or speed increase is required, and therefore, efficient transmission is possible.

Further, the load generated by the hammer action is larger than the load generated by the drill action. Accordingly, in the present embodiment, the 1 st intermediate shaft 41, which receives a larger load, of the 1 st and 2 nd

intermediate shafts

41 and 42, is directly transmitted with torque from the motor shaft 25.

Further, in the 1 st intermediate shaft 41, a driven bevel gear 414 is disposed adjacent to the front side of the bearing 412, and a drive gear 415 is disposed between the driven bevel gear 414 and the motion conversion member 61. That is, the driven bevel gear 414 and the drive gear 415 are disposed adjacent to the bearing 412 that supports the 1 st intermediate shaft 41. Accordingly, the arrangement area of the driven bevel gear 414 and the drive gear 415 in the front-rear direction is minimized. Further, by collectively disposing various gears in the vicinity of the less-deformed bearing 412, the meshing between the drive bevel gear 255 and the driven bevel gear 414 and the meshing between the drive gear 415 and the driven gear 424 can be maintained with high accuracy.

Further, since the motion converting member 61 is mounted on the 1 st intermediate shaft 41, a certain length is required. In contrast, the drive gear 78 mounted on the 2 nd intermediate shaft 42 does not need to have such a length. In particular, in the present embodiment, as described above, since the arrangement of the driven gear 424 on the 2 nd intermediate shaft 42 is determined in correspondence with the drive gear 415 arranged in the vicinity of the bearing 412 on the rear side, a sufficient space is created on the 2 nd intermediate shaft 42 on the front side of the driven gear 424. Therefore, the torque limiter 73 is disposed by effectively utilizing the space. The 2 nd intermediate shaft 42 has a lower transmission torque than the main shaft 31 as the final output shaft. Therefore, the torque limiter 73 can be smaller and lighter than the torque limiter mounted on the main shaft 31.

Further, the torque limiter 73 of the present embodiment is configured to: when the torque limiter 73 is operated, the driven member 75 can be guided in the direction of the rotation axis a4 while rolling the balls 76. This reduces friction between driven

member

75 and 2 nd intermediate shaft 42, thereby stabilizing the operating torque.

In the present embodiment, the drive axis a1, the rotation axis a2 of the motor shaft 25, and the rotation axis A3 of the 1 st intermediate shaft 41 are all located on the reference plane P, while the rotation axis a4 of the 2 nd intermediate shaft 42 is located on the left side of the reference plane P. Accordingly, the center of gravity of the hammer drill 101 is easily shifted to the left of the reference plane P. However, since the right-handed users are more frequently used than the left-handed users, it is conceivable that the user can easily cope with the shift of the center of gravity by attaching the assist grip to the cylindrical portion 111 and holding the same with the left hand. Accordingly, it is reasonable to arrange the rotation axis a4 of the 2 nd intermediate shaft 42 to the left of the reference plane P rather than to the right.

In the present embodiment, the 1 st clutch mechanism 62 and the 2 nd clutch mechanism 71 are provided on the 1 st intermediate shaft 41 and the 2 nd intermediate shaft 42, respectively. Accordingly, the power for performing the hammer operation and the power for performing the drill operation can be cut off as needed. Both the 1 st clutch mechanism 62 and the 2 nd clutch mechanism 71 are switched between the power transmission state and the disengaged state in response to an operation of the same operation member (mode switching dial 800). Accordingly, the user can operate the 1 st clutch mechanism 62 and the 2 nd clutch mechanism 71 by merely operating the mode switching dial 800 to switch the operation mode in accordance with a desired operation. In particular, in the present embodiment, the space generated below the 2 nd intermediate shaft 42 can be used to achieve an appropriate arrangement of the mode switching dial 800 and the mode switching mechanism 80.

The correspondence between the components of the above-described embodiment and the components of the present invention is described below. However, each component of the embodiment is merely an example, and is not intended to limit each component of the present invention. The hammer drill 101 is an example of a "hammer drill". The main shaft 31 is an example of a "final output shaft". The drive axis a1 is an example of a "drive axis". The motor 2 and the motor shaft 25 are examples of a "motor" and a "motor shaft", respectively. The 1 st intermediate shaft 41 is an example of a "1 st intermediate shaft". The impact mechanism 6 is an example of the "1 st drive mechanism". Second countershaft 42 is an example of a "second countershaft". The rotation transmission mechanism 7 is an example of the "2 nd drive mechanism". The drive bevel gear 255 and the driven bevel gear 414 are an example of a "pair of bevel gears". The drive gear 415 and the driven gear 424 are examples of a "pair of gears".

The motion conversion member 61 is an example of a "motion conversion member". The bearing 412 is an example of a "bearing". The driven bevel gear 414 is an example of "one of a pair of bevel gears". The drive gear 415 is an example of "one of a pair of gears". The torque limiter 43 is an example of a "torque limiter". The 1 st clutch mechanism 62 and the 2 nd clutch mechanism 71 are examples of the "1 st clutch mechanism" and the "2 nd clutch mechanism", respectively. The mode switching dial 800 (operation portion 801) is an example of an "operation member".

The above embodiments are merely examples, and the fastening tool according to the present invention is not limited to the illustrated configuration of the hammer drill 101. For example, the following modifications can be added. In addition, only one or a plurality of these modifications can be adopted in combination with the hammer drill 101 shown in the embodiment or the invention described in each of the technical means.

The hammer drill 101 may be configured to operate with electric power supplied from an external ac power source, instead of with electric power supplied from a rechargeable battery. In this case, a power supply line connectable to an external ac power supply is provided instead of the battery mounting portion 173. In addition, the motor 2 may be an ac motor instead of a dc motor, or may be a motor having brushes instead of a brushless motor.

The structures (shapes, constituent members, materials, etc.) of the main body case 10 and the handle 15 may be appropriately changed. For example, the motor housing portion 12 may protrude downward from the rear end portion of the drive mechanism housing portion 11 so as to be orthogonal to the drive axis a 1. In this case, the motor 2 is configured such that the rotation axis a2 of the motor shaft 25 is orthogonal to the rotation axis A3 of the 1 st intermediate shaft 41.

Further, the main body case 10 may have a vibration-proof structure different from the vibration-proof structure exemplified in the above-described embodiment. For example, both end portions of the handle 15 may be elastically coupled to the main body case 10 in a relatively movable manner. Alternatively, the main body case 10 may include an inner case and an outer case, wherein the inner case houses the drive mechanism 5; the outer case includes a grip portion to be gripped by a user, and is elastically coupled to the inner case in a relatively movable manner. Further, the main shaft 31 and the impact mechanism 6 may be supported by a support body inside the main body case 10 and may be integrally movable in the front-rear direction with respect to the main body case 10. Such a vibration-proof structure is disclosed in, for example, japanese patent laid-open publication No. 2016-.

The arrangement of the 1 st countershaft 41 (rotation axis A3) and the 2 nd countershaft 42 (rotation axis a4) with respect to the motor shaft 25 (rotation axis a2) and the arrangement of the 1 st countershaft 41 (rotation axis A3) and the 2 nd countershaft 42 (rotation axis a4) with respect to the main shaft 31 (drive axis a1) are not limited to the arrangements exemplified in the above-described embodiments.

For example, the rotation of motor shaft 25 may be transmitted to 2 nd intermediate shaft 42 first, and further to 1 st intermediate shaft 41, rather than first being transmitted to 1 st intermediate shaft 41. In this case, it is preferable that a driven bevel gear meshed with the drive bevel gear 255 is provided adjacent to the front side of the bearing 422 of the 2 nd intermediate shaft 42, and a drive gear adjacent to the front side thereof is provided. A driven gear may be provided adjacent to the front side of the bearing 412 of the 1 st intermediate shaft 41 and engaged with the drive gear of the 2 nd intermediate shaft 42.

The rotational axis a2 of the motor shaft 25 and the rotational axis A3 of the 1 st countershaft 41 (or the rotational axis a4 of the 2 nd countershaft 42) may not lie on the same plane. In this case, the rotation of motor shaft 25 may be transmitted to 1 st intermediate shaft 41 (or 2 nd intermediate shaft 42) through a hypoid gear, for example. In addition, the drive axis a1 need not lie in the same plane as the rotational axis a2 of the motor shaft 25 and/or the rotational axis A3 of the 1 st countershaft 41.

The configurations and arrangement positions of the 1 st clutch mechanism 62, the 2 nd clutch mechanism 71, the torque limiter 73, and the mode switching mechanism 80 may be changed as appropriate.

For example, the interposing member 63 may be omitted, and the 1 st transmission member 64 of the 1 st clutch mechanism 62 may be movable between a position engaged with the motion converting member 61 (specifically, the rotating body 611) and a position separated from the motion converting member 61. That is, the 1 st transmission member 64 may be configured to directly transmit the rotation of the 1 st intermediate shaft 41 to the motion conversion member 61. In addition, the 2 nd clutch mechanism 71 may be configured to: power is transmitted or disconnected between 2 nd countershaft 42 and drive gear 78 instead of between driven

gear

424 and 2 nd countershaft 42.

The hammer drill 101 may have only the hammer drill mode and the hammer mode among the three action modes of the hammer drill mode, the hammer mode, and the drill mode. In this case, only the 2 nd clutch mechanism 71 may be provided on the 2 nd intermediate shaft 42, and the 1 st clutch mechanism 62 may be omitted. In this case, the 1 st switching member 81 and the 1 st spring 83 of the mode switching mechanism 80 are also omitted.

The driven-side member 75 of the torque limiter 73 and the 2 nd intermediate shaft 42 may be engaged by spline engagement, for example, instead of the balls 76. Instead of the driven-side member 75, the driving-side member 74 may be allowed to move on the 2 nd intermediate shaft 42. In addition, the torque limiter 73 may be omitted or may be provided on the main shaft 31.

In the mode switching mechanism 80, the shape and arrangement of the 1 st switching member 81, the 2 nd switching member 82, the 1 st spring 83, and the 2 nd spring 84, and the interlocking manner with the mode switching dial 800 can be appropriately changed. For example, the 1 st switching member 81 for switching the 1 st clutch mechanism 62 and the 2 nd switching member 82 for switching the 2 nd clutch mechanism 71 may be configured to be moved by separate operating members. The operation member that operates in conjunction with the mode switching mechanism 80 is not limited to a rotary dial, and may be a slide-type operation lever, for example. The 1 st spring 83 and the 2 nd spring 84 may be other types of springs (for example, a tension coil spring or a torsion spring), and the 1 st switching member 81 and the 2 nd switching member 82 may not be biased.

In view of the gist of the present invention and the above-described embodiments, the following embodiments are constructed. The following embodiments can be adopted in combination with the hammer drill 101 and the above-described modification examples described in the embodiments, or the inventions described in the respective embodiments.

[ means 1]

The rotational axis of the motor shaft and the rotational axis of the 1 st intermediate shaft are located on the same plane.

[ means 2]

The rotational axis of the 2 nd intermediate shaft is arranged on the left side with respect to the drive axis.

[ means 3]

The 1 st driving mechanism comprises a swinging part, a piston and an impact piece, wherein,

the oscillating member is disposed on the 1 st intermediate shaft and configured to oscillate in accordance with rotation of the 1 st intermediate shaft;

the piston is configured to reciprocate along the drive axis in accordance with the oscillation of the oscillating member;

the impact member is configured to: the tip tool is linearly moved by an air spring generated by the reciprocating motion of the piston, and is linearly driven.

The motion conversion member 61 (the swinging member 616), the piston 65, and the hammer 67 are examples of the "swinging member", "piston", and "impact tool" in the present embodiment, respectively.

[ means 4]

The 2 nd drive mechanism is constituted as a reduction gear mechanism including a1 st rotation transmission gear and a2 nd rotation transmission gear, wherein,

the 1 st rotation transmission gear is disposed on the 2 nd intermediate shaft and configured to rotate together with the 2 nd intermediate shaft;

the 2 nd rotation transmission gear is provided on an outer periphery of the main shaft, and is engaged with the 1 st rotation transmission gear.

The drive gear 78 and the driven gear 79 are examples of the "1 st rotation transmission gear" and the "2 nd rotation transmission gear" in the present embodiment, respectively.

[ means 5]

A hammer drill is characterized in that the hammer drill is provided with a hammer drill body,

the torque limiter includes a driving-side cam, a driven-side cam, and balls, wherein,

the driven side cam can be engaged with the driving cam;

the balls are configured to be capable of rolling in a track extending in an axial direction of the 2 nd intermediate shaft between an inner periphery of one of the drive-side cam and the driven-side cam and an outer periphery of the 2 nd intermediate shaft,

the one of the driving-side cam and the driven-side cam is configured to be moved in a direction away from the other of the driving-side cam and the driven-side cam in the axial direction while being guided by the balls when a torque acting on the 2 nd intermediate shaft exceeds a threshold value, thereby releasing engagement with the other of the driving-side cam and the driven-side cam.

The driving-side member 74, the driven-side member 75, and the balls 76 are examples of the "driving-side cam", "driven-side cam", and "balls" in the present embodiment, respectively.

[ means 6]

The torque limiter includes a biasing member that biases the one of the driving-side cam and the driven-side cam toward the other.

The biasing spring 77 is an example of a "biasing member" in the present embodiment.

[ means 7]

Further comprising a switching mechanism configured to switch the operation mode in conjunction with the operation member,

the switching mechanism includes a1 st switching member and a2 nd switching member, wherein,

the 1 st switching member is configured to: switching the 1 st clutch mechanism between the power transmission state and the cut-off state in response to movement of the operating member by the manual operation;

the 2 nd switching member is configured to: the 2 nd clutch mechanism is moved in response to the manual operation to switch between the power transmission state and the cut-off state.

The mode switching mechanism 80, the 1 st switching member 81, and the 2 nd switching member 82 are examples of the "switching mechanism", "the 1 st switching member", and "the 2 nd switching member" in the present embodiment, respectively.

[ means 8]

The operating member has a1 st abutting portion and a2 nd abutting portion, wherein,

the 1 st contact portion is configured to contact the 1 st switching member to move the 1 st switching member;

the 2 nd contact portion is configured to contact the 2 nd switching member to move the 2 nd switching member.

The 1 st pin 803 and the 2 nd pin 805 are examples of the "1 st contact portion" and the "2 nd contact portion" in the present embodiment, respectively.

[ means 9]

The 1 st switching member and the 2 nd switching member are movably supported by a single support member.

The support shaft 88 is an example of the "support member" in the present embodiment.

Claims

1. A hammer drill is characterized in that the hammer drill is provided with a hammer drill body,

having a final output shaft, a motor, a1 st intermediate shaft, a1 st drive mechanism, a2 nd intermediate shaft, and a2 nd drive mechanism, wherein,

the final output shaft is configured to detachably hold a tip tool, and the final output shaft is configured to be rotatable about a drive axis thereof;

the motor has a motor shaft extending in a direction intersecting the drive axis;

the 1 st intermediate shaft extends parallel to the drive axis;

the 1 st driving mechanism converts the rotational motion of the 1 st intermediate shaft into a linear motion, and is configured to be capable of performing a hammer action that is an action of linearly driving the tip tool along the driving axis;

the 2 nd intermediate shaft extends parallel to the drive axis;

the 2 nd drive mechanism is configured to transmit rotation of the 2 nd intermediate shaft to the final output shaft and is configured to be capable of performing a drilling operation of driving the tip end tool to rotate about the drive shaft,

the motor shaft is configured to rotate one of the 1 st intermediate shaft and the 2 nd intermediate shaft via a pair of bevel gears,

the one of the 1 st intermediate shaft and the 2 nd intermediate shaft is configured to rotate the other of the 1 st intermediate shaft and the 2 nd intermediate shaft through a pair of gears.

2. The hammer drill according to claim 1,

the motor shaft is configured to rotate the 1 st intermediate shaft,

the 1 st intermediate shaft is configured to rotate the 2 nd intermediate shaft.

3. The hammer drill according to claim 2,

the 1 st drive mechanism includes a motion conversion member disposed on the 1 st intermediate shaft and configured to convert a rotational motion of the 1 st intermediate shaft into a linear motion,

one of the pair of bevel gears is provided on the 1 st intermediate shaft adjacent to a bearing that rotatably supports one end portion of the 1 st intermediate shaft,

one of the pair of gears is disposed between the one of the pair of bevel gears and the motion conversion member on the 1 st intermediate shaft.

4. Hammer drill according to any one of claims 1 to 3,

there is also a torque limiter disposed on the 2 nd intermediate shaft and configured to cut off transmission when the torque acting on the 2 nd intermediate shaft exceeds a threshold value.

5. Hammer drill according to any one of claims 1 to 4,

the rotational axis of the one of the 1 st intermediate shaft and the 2 nd intermediate shaft is located on the same plane as the rotational axis of the motor shaft.

6. The hammer drill according to claim 5,

the drive axes are also located on the same plane.

7. The hammer drill according to claim 6,

defining an extending direction of the drive axis as a front-rear direction of the hammer drill, defining a direction orthogonal to the drive axis and corresponding to an extending direction of the motor shaft as a vertical direction, and defining a direction orthogonal to the front-rear direction and the vertical direction as a horizontal direction,

and a side on which the tip tool is attached is defined as a front side in the front-rear direction, and a side of the drive axis on which the motor is disposed is defined as a lower side in the up-down direction,

in the case where the above-mentioned definition is made,

the rotational axis of the other of the 1 st intermediate shaft and the 2 nd intermediate shaft is disposed on the left side of the plane when facing forward.

8. Hammer drill according to any one of claims 1 to 7,

there is also a1 st clutch mechanism and a2 nd clutch mechanism, wherein,

the 1 st clutch mechanism is provided on the 1 st intermediate shaft and configured to transmit or cut off power for operating the hammer;

the 2 nd clutch mechanism is provided on the 2 nd intermediate shaft, and is configured to transmit or cut off power for performing the drill operation.

9. The hammer drill according to claim 8,

further comprising an operation member configured to be manually operated by a user for switching an operation mode of the hammer drill,

the 1 st clutch mechanism and the 2 nd clutch mechanism are each configured to be switched between a power transmission state and a cut-off state in response to an operation of the operating member.