CN112757231B

CN112757231B - Hammer drill

Info

Publication number: CN112757231B
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: 2024-06-07
Anticipated expiration: 2040-07-07
Also published as: EP3812097B1; EP3812097A1; RU2020134129A; JP7465647B2; CN112757231A; JP2021065958A

Abstract

The invention provides a hammer drill. The hammer drill (101) has 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 intersecting 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 linear motion, and drives the tip tool in a straight line 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 intermediate shaft (41) rotates the 2 nd intermediate shaft (42) through 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 driving a tip tool in a straight line and an operation of driving the tip tool to rotate.

Background

The hammer drill is configured to be capable of performing a hammer operation for driving a tip tool mounted on a tool holder (toolholder) in a straight line along a drive axis and a drill operation for driving the tip tool to rotate about a drive shaft. In general, a motion conversion mechanism that converts rotational motion of an intermediate shaft into linear motion is used for performing hammer motions, and a rotation transmission mechanism that transmits torque to a tool holder through (via) the intermediate shaft is used for performing drill motions. For example, in the hammer drill disclosed in patent document 1, separate intermediate shafts are provided for the motion converting mechanism and the rotation transmitting mechanism.

[ Prior Art literature ]

[ Patent literature ]

Patent document 1: european patent application 2700477

Disclosure of Invention

[ Problem to be solved by the invention ]

In the hammer drill of patent document 1, there is a possibility that the efficiency may be reduced because the spindle rotates the intermediate shaft of the motion conversion mechanism at a higher speed after the intermediate shaft of the rotation transmission mechanism rotates the spindle as the final output shaft (final output shaft) at a lower speed.

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

[ Solution for solving the 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 rotatably arranged 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 drive mechanism converts the rotational motion of the 1 st intermediate shaft into a linear motion, and is configured to be capable of a hammer motion that drives the tip tool in a linear manner along the 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 refers to 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 by a pair of bevel gears (bevel gear). 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.

In the hammer drill of this embodiment, the final output shaft, the 1 st intermediate shaft for the 1 st driving mechanism for performing the hammer operation, and the 2 nd intermediate shaft for the 2 nd driving mechanism for performing the drill operation extend parallel to each other. On the other hand, the motor shaft extends in a direction intersecting with the final output shaft. The rotation of the motor shaft is transmitted to one of the 1 st intermediate shaft and the 2 nd intermediate shaft through the pair of bevel gears, and is further transmitted to the other intermediate shaft through the pair of gears. According to such a 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 performed efficiently without performing unnecessary deceleration or acceleration.

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 preferable because torque is directly transmitted from the motor shaft to the 1 st intermediate shaft receiving the load generated by the hammer operation in this case.

In one aspect of the present invention, the 1 st drive mechanism may include a motion conversion member that is disposed on the 1 st intermediate shaft and is 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 rotatably supporting one end 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 area of the bevel gears and the gears can be made compact in the axial direction of the 1 st intermediate shaft. In addition, by disposing the gears in the vicinity of the bearing having less deformation, the meshing of the pair of bevel gears and the meshing of the pair of gears can be maintained with high accuracy.

In one aspect of the present invention, the hammer drill may further have a torque limiter (torque limiter) that is 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. By providing the 1 st intermediate shaft for the 1 st driving mechanism that performs the hammer operation and the 2 nd intermediate shaft for the 2 nd driving mechanism that performs the drill operation separately, a space is easily created on the 2 nd intermediate shaft. Therefore, the space can be effectively utilized to achieve reasonable arrangement of the torque limiter.

In one aspect of the present invention, the rotation axis of one of the 1 st intermediate shaft and the 2 nd intermediate shaft may be on the same plane as the rotation axis of the motor shaft. In this case, these rotation axes do not become staggered axes, and therefore, a bevel gear having a simple structure can be used. In this embodiment, the drive axes preferably also lie in the same plane. The extending direction of the drive axis is defined as the front-rear direction of the hammer drill, the direction perpendicular to the drive axis and corresponding to the extending direction of the motor shaft is defined as the up-down direction, the direction perpendicular to the front-rear direction and the up-down direction is defined as the left-right direction, the side to which the tip tool is attached is defined as the front side in the front-rear direction, and the side to which the motor is disposed of the drive axis is defined as the lower side in the up-down direction, in which case the rotation axis of the other one of the 1 st intermediate shaft and the 2 nd intermediate shaft may be disposed on the left side of the plane when facing the front.

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

In this 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 operable by a user. Further, the 1 st clutch mechanism and the 2 nd clutch mechanism may each be configured to switch between the power transmission state and the off state in response to an operation of the operation member. In this case, the user can operate the 1 st clutch mechanism and the 2 nd clutch mechanism by switching the operation modes by operating only a single operation member according to a desired job.

Drawings

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

Fig. 2 is a cross-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 partial enlarged view of fig. 1.

Fig. 6 is a view of the internal structure of the driving mechanism housing section as seen 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, A hammer drill; 2: a motor; 5: a driving mechanism; 6: an impact mechanism; 7: a rotation transmission mechanism; 10: a main body housing; 11: a drive mechanism housing part; 12: a motor housing part; 15: a handle; 16: a holding part; 17: a controller housing part; 20: a main body portion; 25: a motor shaft; 31: a main shaft; 32: a tool holder; 33: a piston cylinder; 41: a1 st intermediate shaft; 42: a2 nd intermediate shaft; 43: a torque limiter (torque limiter); 61: a motion conversion part; 62: a1 st clutch mechanism; 63: clamping the component; 64: a1 st transmission member; 65: a piston; 67: ram (striker); 68: a striker; 71: a2 nd clutch mechanism; 72: a2 nd transmission member; 73: a torque limiter; 74: a driving side member; 75: a driven side member; 76: ball (ball); 77: a force spring; 78: a drive gear; 79: a driven gear; 80: a mode switching mechanism; 81: a1 st switching part; 82: a2 nd switching part; 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: driving a 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 member; 424: a driven gear; 425: a spline portion; 611: a rotating body; 614: a bearing; 616: a swinging member; 617: an arm section; 631: a spline portion; 641: a1 st spline portion; 642: a2 nd spline portion; 645: a groove; 721: a1 st spline portion; 722: a2 nd spline portion; 725: a groove; 742: a cam recess; 743: a spline portion; 752: a cam protrusion; 800: a mode switching dial; 801: an operation unit; 803: pin 1; 805: a2 nd pin; 813: a1 st engaging portion; 823: a2 nd engaging portion; 881: a retainer ring; a1: a drive axis; a2: an axis of rotation; a3: an axis of rotation; a4: an axis of rotation; p: a reference surface; 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 the impact tool. The hammer drill 101 is a hand-held power tool used for machining operations such as planing operations and punching operations, and is configured to be capable of performing an operation of driving the tip tool 91 linearly along a predetermined drive axis A1 (hereinafter referred to as a hammer operation) and an operation of driving the tip tool 91 to rotate about the drive axis A1 (hereinafter referred to as a drill operation).

First, a schematic structure 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 a main body casing 10 and a handle 15 coupled to the main body casing 10.

The main body casing 10 is a hollow body, which is also called a tool main body or an outer casing, and accommodates the spindle 31, the drive mechanism 5, the motor 2, and the like. The main shaft 31 is an elongated cylindrical member. The spindle 31 has a tool holder 32 at one end in an axial direction thereof for detachably holding the tip tool 91. The long axis of the spindle 31 defines the 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 driving mechanism housing 11 and a motor housing 12, the driving mechanism housing 11 housing the spindle 31 and the driving mechanism 5, and the motor housing 12 housing the motor 2. The drive mechanism housing 11 extends along a drive axis A1. The tool holder 32 is disposed in one end of the driving mechanism housing 11 in the extending direction of the driving axis A1 (hereinafter, simply referred to as the driving axis direction). The motor housing portion 12 protrudes obliquely from the other end portion of the driving mechanism housing portion 11 in the driving axis direction in a direction away from the driving axis A1. The motor 2 is disposed in the motor housing 12 such that a rotation axis A2 of the motor shaft 25 extends in a direction intersecting the drive axis A1 (specifically, a direction inclined with respect to the drive axis A1).

In the following description, the extending direction of the drive axis A1 is defined as the front-rear direction of the hammer drill 101 for convenience. In the front-rear direction, one end side where the tool holder 32 is disposed is defined as the front side of the hammer drill 101, and the opposite side is defined as the rear side. The direction perpendicular to the drive axis A1, that is, the direction corresponding to the extending direction of the rotation axis A2 of the motor shaft 25 is defined as the up-down direction of the hammer drill 1. In the up-down direction, the direction in which the motor housing 12 protrudes from the driving mechanism housing 11 is defined as the lower direction, and the opposite direction is defined as the upper direction. 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 ends thereof are connected to the main body case 10. The handle 15 includes an elongated tubular grip portion 16 and a rectangular box-shaped controller housing portion 17 connected to the lower side of the grip portion 16. The grip portion 16 is a portion gripped by a user, is disposed apart from the main body case 10 at the rear of the main body case 10, and extends in a substantially vertical direction so as to intersect the drive axis A1. A trigger switch 161 that can be pushed (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 housing 17 houses 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 the battery mounting portion 173 is capable of attaching and detaching a rechargeable battery (battery pack) 93 as a power source of the motor 2 or the like.

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 rotatably supported 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 portion 11 by a biasing spring so as to be movable in the front-rear direction.

In the hammer drill 1, when the trigger switch 161 is operated to turn on the switch 162, the controller 171 energizes the motor 2 to perform the hammer operation and/or the drill operation.

Next, a 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 driving mechanism housing portion 11) and the internal structure thereof will be described.

As shown in fig. 1, the motor housing 12 is a portion of the main body case 10 that is connected to the rear end portion of the driving mechanism housing 11 and extends downward. The motor 2 is accommodated in the motor accommodation portion 12. In the present embodiment, the motor 2 is a brushless dc motor. 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. The motor shaft 25 is rotatably supported by the main body casing 10 about the rotation axis A2 through a bearing 251 and a bearing 252. The rotation axis A2 extends obliquely forward and downward with respect to the drive axis A1. The upper end of the motor shaft 25 protrudes into the drive mechanism housing portion 11. A drive bevel gear 255 is fixed to the upper end of the motor shaft 25.

As shown in fig. 1, the driving mechanism housing 11 is a portion of the main body case 10 that extends along the driving axis A1 and houses the main shaft 31 and the driving 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 portion of the driving mechanism housing portion 11 other than the cylindrical portion 111 is formed in a substantially rectangular box shape. An assist handle (not shown) can be attached to the cylindrical portion 111. The user can grip the assist grip attached to the cylindrical portion 111 in addition to the grip 15.

The spindle 31 is the final output shaft of the hammer drill 101. The main shaft 31 is rotatably supported by the main body case 10 about the drive axis A1 via 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 with its long axis coincident with the drive axis A1, and the tip tool 91 is held in a state in which it is allowed to move in the axial direction with respect to the tool holder 32, and its rotation about the axis is restricted. The latter half of the main shaft 31 constitutes a piston cylinder 33 that slidably holds 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 driving 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 through the 1 st intermediate shaft 41, and is transmitted to the rotation transmission mechanism 7 through 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 the 1 st intermediate shaft 41 and the 2 nd intermediate shaft 42 will be described.

As shown in fig. 1 to 4, the 1 st intermediate shaft 41 and the 2 nd intermediate shaft 42 each extend in parallel with the drive axis A1 in the drive mechanism housing portion 11. As shown in fig. 3, the 1 st intermediate shaft 41 is rotatably supported by the main body case 10 about the rotation axis A3 through two bearings, i.e., a bearing 411 and a bearing 412. Similarly, the 2 nd intermediate shaft 42 is rotatably supported by the main body case 10 about the rotation axis A4 via two bearings, namely, a bearing 421 and a bearing 422.

As shown in fig. 2, in the present embodiment, the rotation axis A3 of the 1 st intermediate shaft 41 extends in parallel with the drive axis A1 immediately below the drive axis A1. 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 up-down 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 meshes with the drive 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 low cost is used as the drive bevel gear 255 and the driven bevel gear 414. Other types of crossed-axis gears (e.g., spiral bevel gears (Spiral bevel gear)) may be employed. 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 adjacent to the front side of the bearing 422 at the rear end portion of the 2 nd intermediate shaft 42. 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 driving gear 415 and the driven gear 424. Further, in the present embodiment, the driving gear 415 and the driven gear 424 have the same diameter. Further, a spur gear (spur gear) having a simple structure and low cost is used as the driving gear 415 and the driven gear 424. Other types of parallel axis gears (e.g., helical gears (HELICAL GEAR)) may be employed.

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 (in detail, a driving side member 74 described later). Further, a spline portion 425 is provided on the outer periphery of the cylindrical distal 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 through the 2 nd transmission member 72 and the torque limiter 73, which will be described later.

Next, the detailed configuration 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 to linearly drive the tool bit 91 along the drive axis A1. 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 ram 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 a linear motion and transmit the linear motion to the piston 65. In more detail, the motion converting member 61 includes a rotating body 611 and a swinging member 616.

The rotary body 611 is rotatably supported by the main body case 10 about a rotation axis A3 via a bearing 614. In the present embodiment, a cylindrical clamping member 63 is interposed between the rotary 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 portion of the clip member 63 projects forward from the front end of the rotating body 611. The swing member 616 is rotatably attached to the outer periphery of the rotating body 611, and swings in the extending direction (front-rear direction) of the rotation axis A3 in accordance with the rotation of the rotating body 611. The swing member 616 has an arm portion 617 extending upward from the rotating body 611.

The piston 65 is a bottomed cylindrical member, and is disposed slidably along the drive axis A1 in the piston cylinder 33 of the main shaft 31. The piston 65 is coupled to the arm portion 617 of the swing member 616 by a coupling pin, and reciprocates in the front-rear direction in accordance with the swing of the swing member 616.

The ram 67 is an impact member for applying an impact force to the tip tool 91. Ram 67 is slidably disposed in piston 65 along drive axis A1. The inner space of the piston 65 on the rear side of the ram 67 is defined as an air chamber functioning as an air spring. Ram 68 is an intermediate piece that transfers the kinetic energy of ram 67 to tip tool 91. The striker 68 is disposed on the front side of the ram 67 in the tool holder 32 so as to be movable along the drive axis A1.

When the piston 65 moves in the front-rear direction with the swinging of the swinging 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, the air in the air chamber is compressed to raise the internal pressure. The striker 67 is pushed forward at a high speed by the air spring to strike the striker 68. Ram 68 transfers the kinetic energy of ram 67 to tip tool 91. Accordingly, the tip tool 91 is driven linearly along the driving axis A1. On the other hand, when the piston 65 moves rearward, the air in the air chamber expands to lower the inner pressure, and the ram 67 is pulled rearward. 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 striking mechanism 6.

In the present embodiment, the rotation of the 1 st intermediate shaft 41 is transmitted to the motion conversion member 61 (in detail, the rotating body 611) through 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 (in 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 a 2 nd spline portion 642 are provided on the inner periphery of the 1 st transmission member 64, wherein the 1 st spline portion 641 can be engaged with the clip 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 rotational axis A3 (front-rear direction). On the other hand, a spline portion 631 is provided on the outer periphery of the tip end portion of the clip member 63. The spline portion 631 has a plurality of splines (external teeth) that can be engaged with the 1 st spline portion 641.

The 2 nd spline portion 642 is provided on the inner periphery of the first 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 rotational axis A3 (front-rear direction). On the other hand, the front end portion (the portion adjacent to the rear side of the front bearing 411) of the 1 st intermediate shaft 41 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 this configuration, as shown by the 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 clamp member 63 in the front-rear direction, the 1 st transmission member 64 can rotate integrally with the clamp member 63 and the rotating body 611, that is, can transmit power from the 1 st intermediate shaft 41 to the motion conversion 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 separated from (unable to engage with) the spline portion 631 (hereinafter referred to as a separated position), the 1 st transmission member 64 cannot transmit power from the 1 st intermediate shaft 41 to the motion conversion member 61 (power transmission is cut off).

As described above, in the present embodiment, the 1 st transmission member 64 and the clamp member 63 function as the 1 st clutch mechanism 62 that transmits or cuts off the power for performing the hammer operation. 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 engaged position and the disengaged position in response to an operation of the mode switching dial 800 (see fig. 2 and 4) by the user. That is, the 1 st clutch mechanism 62 is switched between the power transmission state and the 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 A1. 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 the front end portion (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 rotates integrally with the 2 nd intermediate shaft 42, the main shaft 31 rotates integrally with the driven gear 79. Accordingly, the drill operation is performed to drive the tip tool 91 held by the tool holder 32 to rotate about the drive axis A1.

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. The torque limiter 73 and the 2 nd transmission 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 intermediate shaft 42 and is configured to cut off transmission when the torque applied to the 2 nd intermediate shaft 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 a biasing spring 77.

The driving-side member 74 is a cylindrical member, and is rotatably supported by the second 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 driving side member 74 includes a cam recess 742 (see 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 (front-rear direction).

The driven-side member 75 is a cylindrical member, and is disposed around the 2 nd intermediate shaft 42 on the front side of the 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-side member 75. Further, a plurality of grooves extending in the direction of the rotation axis 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 received in tracks defined by the grooves. Accordingly, the driven side member 75 is engaged with the 2 nd intermediate shaft 42 by the balls 76 in the radial and circumferential directions, and is rotatable integrally with the 2 nd intermediate shaft 42. 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 projection 752 (see fig. 4) provided at the rear end. Although not shown in detail, the cam projection 752 has a shape substantially matching the cam recess 742 of the driving side member 74, and has a cam surface inclined in the circumferential direction. The urging 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 urging spring 77 always urges the driven-side member 75 in a direction approaching the driving-side member 74, that is, in a direction (rearward) in which the cam projection 752 and the cam recess 742 engage. When the cam projection 752 and the cam recess 742 are engaged with each other, torque can be transmitted from the driving member 74 to the driven member 75, and the 2 nd intermediate shaft 42 can be rotated. The driving side member 74 and the gear member 423 are biased rearward by the driven side member 75, and are held at 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 (the main shaft 31) due to, for example, the locking of the tip tool 91 during rotation of the 2 nd intermediate shaft 42, the engagement between the cam projection 752 and the cam recess 742 is released. More specifically, the cam projection 752 and the cam recess 742 are separated from each other by the cam surface (inclined surface) of the cam projection 752 and the cam recess 742 against the urging force of the urging spring 77, and the cam projection 752 and the cam recess 742 are moved to the front end surface of the drive-side member 74. That is, the driven-side member 75 moves in a direction (forward) away from the driving-side member 74. At this time, the driven side member 75 is guided by the balls 76 rolling between the driven side member and the 2 nd intermediate shaft 42, and can smoothly move forward. As a result, the torque transmission from the driving side member 74 to the driven side member 75 is cut off, and the rotation of the 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 driving side member 74 of the torque limiter 73, and is movable in the direction of the rotation axis A4 (front-rear direction) with respect to the driving 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 in the front half of the 2 nd transmission member 72. The 1 st spline portion 721 has a plurality of splines (internal teeth) that are always engaged with the spline portion 743 of the drive side member 74. The 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 be engaged 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 engaged position, the 2 nd transmission member 72 can transmit power from the gear member 423 to the 2 nd intermediate shaft 42 through 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 separated from (unable to engage with) the spline portion 425 (hereinafter referred to as a separated position), the 2 nd transmission member 72 cannot transmit power from the gear member 423 to the 2 nd intermediate shaft 42 (power transmission is cut).

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 drilling operation. In the present embodiment, the 2 nd transmission member 72 is connected to the mode switching mechanism 80 (see fig. 6) similarly to the 1 st transmission member 64, and moves between the engaged position and the disengaged 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 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 are explained.

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 association 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 hammer operation and the drill operation are performed by driving the impact mechanism 6 and the rotation transmission mechanism 7. 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 rotation transmission mechanism 7 is driven by cutting off the power transmission for the hammer operation by the 1 st clutch mechanism 62, thereby performing only the drill operation.

As shown in fig. 2, 4, and 6, the mode switching dial 800 is provided on the left side of the main body case 10 (in detail, the driving 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 1 st and 2 nd pins 803 and 805 protruding from the operation portion 801.

The operation unit 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 from an opening portion formed in the left side wall of the main body case 10 (driving mechanism housing portion 11), and can be rotated by a user. 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 disposing 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 toward the inside of the main body case 10. The 1 st pin 803 and the 2 nd pin 805 move on a circumference centering on the rotation axis R of the operation portion 801 in accordance with the rotation of the mode switching dial 800.

The mode switching mechanism 80 includes a1 st switching member 81, a 2 nd switching member 82, a1 st spring 83, and a 2 nd spring 84.

The 1 st switching member 81 has a pair of support holes (not shown), and is supported so as to be movable in the front-rear direction by a support shaft 88 inserted through the support holes. The support shaft 88 is supported by the main body case 10 (specifically, by a support wall 113 fixed to the inside of 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 in the axial direction of the support shaft 88. The 1 st switching member 81 is supported on the front side of the retainer ring 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 ring 881 so as to be movable in the front-rear direction by a support shaft 88 inserted through the support holes.

The 1 st switching member 81 and the 2 nd switching member 82 are engaged with the 1 st transmission member 64 and the 2 nd transmission member 72, respectively. More specifically, annular grooves 645 and 725 are provided on the outer peripheries of the 1 st transmission member 64 and the 2 nd transmission member 72, respectively. The 1 st switching member 81 is engaged with the 1 st transmission member 64 by a plate-like 1 st engagement 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 coil compression spring (compression coil spring), is arranged in a compressed state between the drive mechanism housing portion 11 and the 1 st switching member 81, and always biases the 1 st switching member 81 rearward. Accordingly, the 1 st transmission member 64 engaged with the 1 st switching member 81 is always biased to the rearward engagement position. The 2 nd spring 84 is a coil compression spring, and is disposed in a compressed state between the retainer ring 881 fixed to the support shaft 88 and the 2 nd switching member 82, and always biases the 2 nd switching member 82 rearward. Accordingly, the 2 nd transmission member 72 engaged with the 2 nd switching member 82 is 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 retainer ring 881. The rearmost position of the 2 nd switching member 82 is a position where the 2 nd switching member 82 abuts against the front surface of the support wall 113.

When the mode switching dial 800 is disposed at a rotational position (hereinafter, referred to as a hammer drill position) corresponding to the hammer drill mode 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 is engaged with the spline portion 631 of the clip 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 drive bevel gear 255 and the driven bevel gear 414. 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. At the same time, power is transmitted from the 1 st intermediate shaft 41 to the 2 nd intermediate shaft 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. The power is transmitted from the 2 nd intermediate shaft 42 to the main shaft 31 through the rotation transmission mechanism 7, and the drilling operation is also performed.

When the mode switching dial 800 is operated to rotate from the hammer drill position shown in fig. 6 to a rotation position (hereinafter, referred to as a hammer position) corresponding to the hammer mode shown in fig. 7, the 2 nd pin 805 moves clockwise while abutting against the 2 nd switching member 82 from the rear, and simultaneously moves the 2 nd switching member 82 forward against the urging force of the 2 nd spring 84. When the mode switching dial 800 is arranged at the hammer position, the 2 nd switching member 82 is arranged at the foremost position. The 2 nd transmission member 72 moves from the engagement position to the release position (see fig. 4) with the movement of the 2 nd switching member 82, and the 2 nd clutch mechanism 71 is switched to the off state.

On the other hand, when the 1 st pin 803 does not interfere with the 1 st switching member 81 or the 2 nd switching member 82, it moves 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. Accordingly, during this period, 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 the motor shaft 25 to the 2 nd intermediate shaft 42 even if the motor 2 is energized, no drilling operation is 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 a rotation position (hereinafter referred to as drill position) corresponding to the drill mode shown in fig. 8, the 1 st pin 803 contacts the 1 st switching member 81 from behind, moves counterclockwise around the rotation axis R of the operation portion 801 as seen from the bottom, and moves the 1 st switching member 81 forward against the urging force of the 1 st spring 83. When the mode switching dial 800 is arranged at the drill position, the 1 st switching member 81 is arranged at the foremost position. The 1 st transmission member 64 moves from the engaged position to the disengaged position (see fig. 5) in association 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 the 1 st switching member 81 or the 2 nd switching member 82, it moves counterclockwise around the rotation axis R of the operation unit 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 transmitting 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 action is not performed. On the other hand, since power is transmitted from the motor shaft 25 to the rotation transmission mechanism 7 through the 2 nd intermediate shaft 42, only the drilling 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 for performing the hammer operation, and the 2 nd intermediate shaft 42 used for the rotation transmission mechanism for performing the drill operation extend parallel to each other. On the other hand, the motor shaft 25 extends in a direction intersecting the main shaft 31. The rotation of the motor shaft 25 is transmitted to the 1 st intermediate shaft 41 through the drive bevel gear 255 and the driven bevel gear 414, and transmitted to the 2 nd intermediate shaft 42 through the drive gear 415 and the driven gear 424. That is, the main shaft 31 is not located on the transmission path between the 1 st intermediate shaft 41 and the 2 nd intermediate shaft 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 reduction or acceleration is required, and therefore efficient transmission is possible.

In addition, 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 having a larger load to be applied is configured to directly transmit torque from the motor shaft 25 to the 1 st intermediate shaft 41 and the 2 nd intermediate shaft 42.

In addition, on 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 driving gear 415 in the front-rear direction is minimized. Further, by disposing various gears in the vicinity of the bearing 412 having less deformation, the meshing of the drive bevel gear 255 and the driven bevel gear 414 and the meshing of the drive gear 415 and the driven gear 424 can be maintained with high accuracy.

Further, since the motion conversion 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 also determined in correspondence with the drive gear 415 arranged in the vicinity of the bearing 412 on the rear side, a sufficient space is generated on the front side of the driven gear 424 on the 2 nd intermediate shaft 42. Therefore, the torque limiter 73 is disposed by effectively utilizing the space. The transmission torque of the 2 nd intermediate shaft 42 is lower than that of 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.

The torque limiter 73 of the present embodiment is configured to: when the torque limiter 73 operates, the driven member 75 can be guided in the direction of the rotation axis A4 while rolling the balls 76. Accordingly, friction between the driven side member 75 and the 2 nd intermediate shaft 42 can be reduced, and the operating torque can be stabilized.

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 there are more users with right hand than users with left hand, 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 it with the left hand. Accordingly, it is reasonable to dispose the rotation axis A4 of the 2 nd intermediate shaft 42 on the left side of the reference plane P instead of the right side.

In the present embodiment, the 1 st clutch mechanism 62 and the 2 nd clutch mechanism 71 are provided to 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, respectively, as needed. The 1 st clutch mechanism 62 and the 2 nd clutch mechanism 71 are each switched between the power transmission state and the off state in response to an operation of the same operation member (the mode switching dial 800). Accordingly, the user can operate the 1 st clutch mechanism 62 and the 2 nd clutch mechanism 71 by switching the operation mode by operating the mode switching dial 800 only in accordance with a desired operation. In particular, in the present embodiment, the space generated below the 2 nd intermediate shaft 42 can be utilized to realize reasonable arrangement of the mode switching dial 800 and the mode switching mechanism 80.

The correspondence between each component of the above embodiment and each component of the present invention is shown below. However, the constituent elements of the embodiment are merely examples, and the constituent elements of the present invention are not limited thereto. 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 "motor" and "motor shaft", respectively. The 1 st intermediate shaft 41 is an example of the "1 st intermediate shaft". The impact mechanism 6 is an example of the "1 st drive mechanism". The 2 nd intermediate shaft 42 is an example of the "2 nd intermediate shaft". 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 examples of "a pair of bevel gears". The driving gear 415 and the driven gear 424 are examples of "a pair of gears".

The motion conversion member 61 is an example of "motion conversion member". 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 section 801) is an example of "operation member".

The above-described 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 exemplified modifications can be added. In addition, only one or more of these modifications can be adopted in combination with the hammer drill 101 shown in the embodiment or the inventions described in the respective embodiments.

The hammer drill 101 may be configured to operate by electric power supplied from an external ac power supply, instead of by electric power supplied from a rechargeable battery. In this case, a power line connectable to an external ac power supply is provided in place 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 (shape, constituent members, materials, etc.) of the main body case 10 and the handle 15 may be changed as appropriate. For example, the motor housing 12 may protrude downward from the rear end of the driving mechanism housing 11 so as to be orthogonal to the driving axis A1. 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.

The main body case 10 may have a vibration isolation structure different from that exemplified in the above 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. Or the main body housing 10 may include an inner housing that houses the driving mechanism 5 and an outer housing; the outer housing includes a grip portion for a user to grip, and is elastically coupled to the inner housing in a relatively movable manner. Further, the main shaft 31 and the impact mechanism 6 may be supported by a support body in the main body case 10 so as to be integrally movable in the front-rear direction with respect to the main body case 10. Such a vibration isolation structure is disclosed in, for example, japanese patent laying-open No. 2016-000447.

The arrangement of the 1 st intermediate shaft 41 (rotation axis A3) and the 2 nd intermediate shaft 42 (rotation axis A4) with respect to the motor shaft 25 (rotation axis A2) and the arrangement of the 1 st intermediate shaft 41 (rotation axis A3) and the 2 nd intermediate shaft 42 (rotation axis A4) with respect to the main shaft 31 (drive axis A1) are not limited to those exemplified in the above embodiment.

For example, it is possible that the rotation of the motor shaft 25 is first transmitted to the 2 nd intermediate shaft 42, further to the 1 st intermediate shaft 41, instead of being first transmitted to the 1 st intermediate shaft 41. In this case, it is preferable to provide a driven bevel gear adjacent to the front side of the bearing 422 of the 2 nd intermediate shaft 42 and engaged with the drive bevel gear 255, and to provide a drive gear adjacent to the front side thereof. Further, 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 driving gear of the 2 nd intermediate shaft 42.

The rotation axis A2 of the motor shaft 25 and the rotation axis A3 of the 1 st intermediate shaft 41 (or the rotation axis A4 of the 2 nd intermediate shaft 42) may not be on the same plane. In this case, the rotation of the motor shaft 25 may be transmitted to the 1 st intermediate shaft 41 (or the 2 nd intermediate shaft 42) through a hypoid gear (hypoid gear), for example. In addition, the drive axis A1 does not need to be on the same plane as the rotation axis A2 of the motor shaft 25 and/or the rotation axis A3 of the 1 st intermediate shaft 41.

The configuration 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 sandwiching 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 where it engages with the motion conversion member 61 (specifically, the rotating body 611) and a position where it is separated from the motion conversion 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. The 2 nd clutch mechanism 71 may be configured as follows: the transmission or cutoff of power is performed between the 2 nd intermediate shaft 42 and the drive gear 78, not between the driven gear 424 and the 2 nd intermediate shaft 42.

The hammer drill 101 may have only the hammer drill mode and the hammer mode among three operation 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, for example, spline-engaged, instead of being engaged by 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, arrangement, and linkage with the mode switching dial 800 of the 1 st switching member 81, the 2 nd switching member 82, the 1 st spring 83, and the 2 nd spring 84 may 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 operation members. The operation member that is linked to 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 (e.g., tension coil springs and torsion springs), 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 modes can be adopted in combination with the hammer drill 101 shown in the embodiment and the modification described above, or the inventions described in the respective embodiments.

Mode 1

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

Mode 2

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

Mode 3

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

The swinging member is arranged on the 1 st intermediate shaft and configured to swing along with the rotation of the 1 st intermediate shaft;

the piston is configured to reciprocate along the drive axis with the swinging of the swinging member;

The impact piece is configured as follows: 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 (swing member 616), the piston 65, and the ram 67 are examples of "swing member", "piston", and "striker" in the present embodiment, respectively.

Mode 4

The 2 nd driving mechanism is 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 the 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.

Mode 5

A hammer drill is characterized in that,

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

The driven side cam is engageable with the drive 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 driving side cam and the driven side cam and an outer periphery of the 2 nd intermediate shaft,

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

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

Mode 6

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

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

Mode 7

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

The switching mechanism comprises a1 st switching component and a 2nd switching component, wherein,

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

The 2 nd switching means is configured to: the 2 nd clutch mechanism is switched between the power transmission state and the cut-off state in response to movement of the manual operation.

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

Mode 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.

Mode 9

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

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

Claims

1. A hammer drill is characterized in that,

Has a final output shaft, a motor, a 1 st intermediate shaft, a 1 st driving mechanism, a2 nd intermediate shaft and a2 nd driving mechanism, wherein,

The final output shaft is configured to removably retain a tip tool, and the final output shaft is rotatably configured 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 a hammer motion that linearly drives the tip tool along the driving axis;

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 perform a drilling operation of driving the tip tool to rotate about the drive axis,

The motor shaft is configured to rotate the 1 st intermediate shaft by a drive bevel gear provided to the motor shaft and a driven bevel gear provided to the 1 st intermediate shaft and engaged with the drive bevel gear,

The 1 st intermediate shaft is configured to rotate the 2 nd intermediate shaft by a drive gear provided to the 1 st intermediate shaft and a driven gear provided to the 2 nd intermediate shaft and meshed with the drive gear,

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

The extending direction of the driving axis is defined as a front-rear direction of the hammer drill, and a side to which the tip tool is attached in the front-rear direction is defined as a front side,

In the case where the above-mentioned regulation is performed,

The driven bevel gear of the 1 st intermediate shaft is disposed adjacent to a front side of a1 st bearing, wherein the 1 st bearing refers to a bearing rotatably supporting a rear end portion of the 1 st intermediate shaft,

The drive gear of the 1 st intermediate shaft is disposed between the driven bevel gear and the motion conversion member in the front-rear direction,

In the front-rear direction, the driven bevel gear of the 1 st intermediate shaft is located on the front side of the drive bevel gear of the motor shaft,

The drive gear of the 1 st intermediate shaft is disposed adjacent to a front side of the driven bevel gear.

2. The hammer drill according to claim 1, wherein,

The 1 st intermediate shaft is rotatably supported by two bearings,

The front end portion of the 1 st intermediate shaft is adjacent to the rear side of the 3 rd bearing located on the front side, which is supported so as to be capable of rotating the 1 st intermediate shaft, of the two bearings.

3. Hammer drill according to claim 1 or 2, characterized in that,

The 1 st bearing rotatably supporting the rear end portion of the 1 st intermediate shaft and the 2 nd bearing rotatably supporting the rear end portion of the 2 nd intermediate shaft are supported on a common support wall.

4. Hammer drill according to claim 1 or 2, characterized in that,

The engine further includes a torque limiter that is disposed on the 2 nd intermediate shaft and configured to cut off transmission when a torque acting on the 2 nd intermediate shaft exceeds a threshold value.

5. Hammer drill according to claim 1 or 2, characterized in that,

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

6. The hammer drill according to claim 5, wherein,

The drive axes also lie on the same plane.

7. The hammer drill according to claim 6, wherein,

A direction perpendicular to the drive axis and corresponding to an extending direction of the motor shaft is defined as an up-down direction, a direction perpendicular to the front-back direction and the up-down direction is defined as a left-right direction,

And the side of the driving axis on which the motor is arranged is defined as a lower side in the up-down direction,

In the case where the above-mentioned regulation is performed,

When facing forward, the rotation axis of the 2 nd intermediate shaft is arranged on the left side of the plane.

8. Hammer drill according to claim 1 or 2, characterized in that,

Also has a1 st clutch mechanism and a 2 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 performing the hammer action;

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

9. The hammer drill according to claim 8, wherein,

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

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