CN117283499A - Impact tool - Google Patents

Abstract

The invention provides an impact tool. The impact tool has a tool body, a handle, and a plurality of urging members, the tool body housing a motor and a driving mechanism and extending in the front-rear direction; the handle comprises a holding part which extends in the vertical direction orthogonal to the front-back direction at the rear of the tool body, and the lower end of the holding part is formed as a free end and is arranged below the driving axis; the plurality of force applying members elastically connect the tool body with the handle. The plurality of urging members have at least 1 st urging member disposed above the drive axis in the up-down direction; and at least 1 2 nd urging member arranged below the drive axis in the up-down direction. In the impact tool, the force of at least 1 2 nd force applying member is larger than the force of at least 1 st force applying member. Accordingly, the posture of the impact tool during the machining operation can be stabilized.

Description

Impact tool

Technical Field

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

Background

In an impact tool that performs a machining operation on a workpiece by driving a tip tool in a straight line along a drive axis, particularly large vibrations are generated in the direction in which the drive axis extends. In this regard, various vibration-proof housing structures have been proposed. For example, in an impact tool (hammer drill) disclosed in japanese patent application laid-open No. 6334144, a handle is elastically connected to a tool body housing a motor and a driving mechanism by a biasing member so as to be movable in an extending direction of a driving axis. The user performs a machining operation so as to press the grip (handle) against the workpiece.

Disclosure of Invention

According to the structure disclosed in japanese patent application laid-open No. 6334144, vibration in the extending direction of the drive axis can be effectively suppressed from being transmitted from the tool body to the handle during the machining operation. On the other hand, in an impact tool in which a grip portion is provided below a drive axis and a lower end of the grip portion (handle) is a free end, the lower end of the handle is easily inclined so as to approach a workpiece during a machining operation.

In view of the above, a non-limiting object of the present invention is to provide a technique for stabilizing the posture of an impact tool during a machining operation.

According to one aspect of the present invention, there is provided an impact tool configured to linearly drive a tip tool. The impact tool has a motor, a driving mechanism, a tool body, a handle, and a plurality of urging members. The driving mechanism is configured to drive the tip tool along a driving axis defining a front-rear direction of the impact tool by power of the motor. The tool body accommodates the motor and the driving mechanism, and extends in the front-rear direction. The handle includes a grip. The grip portion extends in a vertical direction orthogonal to the front-rear direction at a rear of the tool body. The lower end of the holding part is formed as a free end. The plurality of urging members are configured to elastically connect the tool body and the handle, and to urge the tool body and the handle apart from each other in the front-rear direction. The plurality of urging members include at least 1 st urging member disposed above the drive axis in the up-down direction and at least 1 st urging member disposed below the drive axis in the up-down direction. The force of the at least 1 2 nd force applying member is greater than the force of the at least 1 st force applying member.

In an impact tool in which a tool body and a handle are elastically connected, a working operation is performed so as to press a grip portion against a workpiece. In an impact tool in which the grip portion is offset downward with respect to the drive axis and the lower end of the grip portion (grip) is a free end, the grip portion is farther from the drive axis. Therefore, in the machining operation, the handle (impact tool) is easily tilted so that the lower end portion of the handle approaches the workpiece. According to the impact tool of the above aspect, since the force of at least 1 of the 2 nd force application members is greater than the force of at least 1 of the 1 st force application members, the force on the side closer to the grip portion is greater than the force on the side farther from the grip portion. Therefore, tilting of the handle during the machining operation can be suppressed. Thus, the posture of the impact tool during the machining operation can be stabilized.

Drawings

Fig. 1 is an external view of a hammer drill.

Fig. 2 is a cross-sectional view of the hammer drill.

Fig. 3 is a cross-sectional view of the hammer drill of fig. 2 at III-III.

Fig. 4 is a cross-sectional view of the hammer drill of IV-IV of fig. 3.

Fig. 5 is a cross-sectional view of the V-V hammer drill of fig. 3.

Fig. 6 is a diagram showing the spring holder and the 2 nd biasing spring.

Fig. 7 is a view showing a state in which the 2 nd biasing spring is held by the spring holder.

Fig. 8 is a view showing a state in which the 2 nd biasing spring is held by the spring holder, and is a view for explaining the 1 st locking portion of the spring holder.

Fig. 9 is a diagram showing a state in which a left side portion is assembled to a motor case.

Fig. 10 is a partial enlarged view of fig. 9.

Fig. 11 is a view showing a state in which a handle is assembled to a tool body.

Fig. 12 is a view showing a state in which the 2 nd biasing spring is disposed between the tool body and the handle.

Fig. 13 is a view of a part of the hammer drill 1B of embodiment 2 cut through the plane P2, and shows the arrangement relationship of the 1 st biasing member and the 2 nd biasing member.

Fig. 14 is a view of a part of the hammer drill 1C of embodiment 3 taken along a plane P2, and is a partial cross-sectional view showing the arrangement relationship of the 1 st biasing member and the 2 nd biasing member.

[ description of reference numerals ]

1A, 1B, 1C: a hammer drill; 2A: a tool body; 21: a gear housing; 22: a rear end portion; 221. 222, 223, 224: a1 st connection part; 23: a motor housing; 24: a front portion; 241. 242, 243, 244: a2 nd connecting part; 24s: an outer surface; 28: a guide section; 29: a guide plate; 26: a rear portion; 261: a corner; 263: an upper wall; 265: a front wall; 266: a rear wall; 27: a1 st spring holding part; 271: an abutment surface; 272: a retaining wall; 3A: a handle; 30L: a left side portion; 30R: a right side portion; 31: a cover section; 311: an opening; 33: a1 st spring holding part; 331: an abutment surface; 332: a retaining wall; 34: a guide receiving portion; 35. 35B, 35C: a2 nd spring holding part; 351: an abutment surface; 352: a retaining wall; 36B: a2 nd spring holding part; 361: an abutment surface; 39: a holding part; 391: an upper end; 392: a lower end; 4L, 4R: a spring holder; 41: a1 st locking part; 42: an outer wall; 42s: an outer surface; 43: a support section; 431: 1 st surface; 44: a rear wall; 441: a front surface; 442: a rear surface; 45: an engagement portion; 46: a protruding portion; 51: a1 st force application spring; 511: a front end; 512: a rear end; 52L, 52R, 52B, 52C: a2 nd force application spring; 521: a front end; 522: a rear end; 61. 62: a hole; 622: an opening; 63L, 63R: a holder receiving section; 621: a2 nd locking part; 631: 1 st surface; 632: 2 nd surface; 71: a motor; 711: a motor shaft; 72: a fan; 75: a driving mechanism; 751: a motion conversion mechanism; 752: an impact mechanism; 753: a rotation transmission mechanism; 79: a tool holder; 91: a corrugated member; 92: a trigger; 93: a switch; 94: a power line; 95: a screw; 952: a rear end; 96: an operation handle; 101: a tip tool; a1: a drive axis; a2: an axis of rotation; l1: a distance; l2: a distance; p1: an imaginary plane; p2: an imaginary plane.

Detailed Description

In a non-limiting embodiment of the present invention, the at least 1 st force application member and the at least 1 st force application member may be the same size. The number of the at least 1 st force application member 2 may be larger than the number of the at least 1 st force application member 1.

According to this embodiment, the force applied to the grip portion side can be made larger than the force applied to the grip portion side by using the same-sized force applying member. Therefore, the cost for suppressing the tilting of the impact tool during the machining operation can be reduced. The same-sized biasing members refer to the same-shaped biasing members formed of the same material.

In addition to or instead of the above embodiment, the number of the at least 1 st force application members may be 1, and the number of the at least 1 2 nd force application members may be 2.

According to this embodiment, the force on the side closer to the grip can be made larger than the force on the side farther from the grip. Therefore, tilting of the impact tool during the machining operation can be suppressed.

In addition to or instead of the above embodiment, the 2 nd urging members may be provided symmetrically with respect to a virtual plane including the drive axis and extending in the up-down direction.

According to this embodiment, the force acting between the tool body and the handle at the lower side of the drive axis can be equalized in the left-right direction. Therefore, the machining operation can be stably performed.

In addition to or instead of the above embodiment, the spring constant of the at least 1 2 nd urging member may be larger than the spring constant of the at least 1 2 nd urging member.

According to this embodiment, the force on the side closer to the grip portion can be made larger than the force on the side farther from the grip portion by utilizing the difference in spring constant.

In addition to or instead of the above embodiment, the at least 1 st force application member may be disposed between the tool body and the handle in a state where an initial load larger than the at least 1 st force application member is applied.

According to this embodiment, the force on the side closer to the grip portion can be made larger than the force on the side farther from the grip portion by utilizing the difference in initial load. The "state in which the initial load is applied" means a state in which the biasing spring is applied with a load in the compression direction in the static state, and the biasing spring is compressed.

In addition to or instead of the above embodiment, the at least 1 st force application member 2 may be provided in front of the at least 1 st force application member 1.

According to this embodiment, the space behind the 2 nd urging member (in front of the upper end of the grip portion) can be effectively utilized as compared with a structure in which at least 1 st urging member is provided on the front side of at least 12 nd urging member. Therefore, the impact tool can be compactly constructed.

In addition to or instead of the above embodiment, the tool body may include a motor housing that is disposed at a rear portion of the tool body and accommodates the motor. The handle may comprise a cover portion at least partially surrounding the motor housing. The upper end of the grip portion may be connected to the cover portion.

According to this embodiment, the motor housing can be covered with the handle, while suppressing tilting of the impact tool during the machining operation.

Representative and non-limiting embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

< embodiment 1 >

A hammer drill 1A according to a representative and non-limiting embodiment of the present invention will be described with reference to fig. 1 to 12. The hammer drill 1A is an example of an electric tool (so-called impact tool) that can linearly drive the tip tool 101 by impacting the tip tool 101. More specifically, the hammer drill 1A is an electric tool capable of performing an operation (hereinafter referred to as a striking operation) of driving the tip tool 101 in a straight line along a predetermined driving axis A1 and an operation (hereinafter referred to as a rotating operation) of rotationally driving the tip tool 101 about the driving axis A1.

As shown in fig. 1, the hammer drill 1A mainly includes a tool body 2A, a handle 3A, and a plurality of biasing members that elastically connect the tool body 2A and the handle 3A. As shown in fig. 2 to 5, the hammer drill 1A of the present embodiment has 3 urging springs (1 st urging spring 51, 2 nd urging springs 52L, 52R) as a plurality of urging members.

The tool body 2A is a hollow body that accommodates a main mechanism of the hammer drill 1A. The tool body 2A is also called a body housing, a profile housing, and a body portion. As shown in fig. 2, the tool body 2A extends along the drive axis A1 of the tip tool 101. A tool holder 79 is disposed in one end portion of the tool body 2A in the extending direction of the drive axis A1 (hereinafter, simply referred to as the drive axis direction). The tip tool 101 can be detachably attached to the tool holder 79. The tool main body 2A mainly accommodates a motor 71 and a driving mechanism 75, and the driving mechanism 75 is configured to drive the distal end tool 101 held by the tool holder 79 by power of the motor 71. In the present embodiment, the motor 71 is arranged such that the rotation axis A2 of the motor shaft 711, which rotates integrally with the rotor, extends parallel to the drive axis A1. In the present embodiment, a brush motor is used as the motor 71.

The handle 3A is formed separately from the tool body 2A. The handle 3A is connected to the tool body 2A so as to be movable in the driving axis direction with respect to the tool body 2A. The handle 3A has a grip 39 that can be gripped by a user. The grip 39 extends so as to protrude from the tool body 2A in a direction intersecting the drive axis A1 (specifically, in a direction substantially orthogonal to the drive axis A1 and the rotation axis A2). The protruding end 392 of the grip 39 is a free end. The grip portion 39 has a trigger 92 that is pressed (pulled) by a user. In the hammer drill 1A, the motor 71 is energized in response to the pressing operation of the trigger 92, and the driving mechanism 75 is driven, whereby the striking action and/or the rotating action is performed.

Next, the detailed structure of the hammer drill 1A will be described. In the following description, for convenience, the extending direction of the drive axis A1 (the longitudinal direction of the tool body 2A) is defined as the front-rear direction of the hammer drill 1A. In the front-rear direction, the side on which the tool holder 79 is disposed is defined as the front side of the hammer drill 1A, and the opposite side is defined as the rear side. A direction (a direction orthogonal to the drive axis A1 and the rotation axis A2) orthogonal to the drive axis A1 and substantially corresponding to the extending direction of the grip portion 39 is defined as the vertical direction of the hammer drill 1A. In the vertical direction, the base end 391 side of the grip 39 is defined as the upper side of the hammer drill 1A, and the protruding end 392 side of the grip 39 is defined as the lower side of the hammer drill 1A. The direction orthogonal to the front-rear direction and the up-down direction is defined as the left-right direction of the hammer drill 1A. In the following, for convenience of explanation, a virtual plane including the drive axis A1 and orthogonal to the vertical direction is also referred to as a plane P1, and a virtual plane including the drive axis A1 and parallel to the vertical direction is referred to as a plane P2 (see fig. 3). In the present embodiment, the handle 3A has 2 split bodies (a left side portion 30L and a right side portion 30R) connected to each other in the left-right direction. The plane P2 divides the handle 3A into a left side portion 30L and a right side portion 30R.

First, the structure of the tool body 2A and its internal structure are explained.

The tool body 2A includes a gear housing 21, a motor housing 23, 2 holder receiving portions 63L, 63R, a plurality of guide portions 28, and a 1 st spring holding portion 27.

As shown in fig. 2, the gear housing 21 is a hollow body accommodating the drive mechanism 75. The gear housing 21 constitutes the front half of the tool body 2A. The front end portion of the gear housing 21 is formed in a cylindrical shape, and a tool holder 79 is disposed therein. The portion of the gear housing 21 other than the front end portion is formed in a substantially rectangular tubular shape. Since the structure is well known, a detailed description is omitted, and the driving mechanism 75 includes a motion conversion mechanism 751 and an impact mechanism 752 for performing an impact operation, and a rotation transmission mechanism 753 for performing a rotation operation. In the present embodiment, the motion conversion mechanism 751 employs a mechanism that converts rotational motion into linear motion by using a wobble member (e.g., a wobble plate/wobble bearing) and a piston. However, a motion conversion mechanism using a crankshaft, for example, may be employed instead of the swinging member. The rotation transmission mechanism 753 may be a reduction mechanism including a plurality of gears.

In the present embodiment, the hammer drill 1A has 3 operation modes, that is, an impact mode (percussion only) in which only an impact operation is performed, a rotation mode (rotation only) in which only a rotation operation is performed, and a rotation impact mode (hammering with rotation) in which both an impact operation and a rotation operation are performed. Since these are also well known structures, detailed illustration and description are omitted, and the driving mechanism 75 operates in response to an operation mode selected by the user via the mode switching knob.

As shown in fig. 2, the motor housing 23 is a hollow body accommodating the motor 71. The motor housing 23 is a single member (seamless member) formed separately from the gear housing 21. The motor housing 23 constitutes the rear half of the tool body 2A. The motor housing 23 is formed of synthetic resin.

The motor housing 23 is formed in a substantially cylindrical shape with an open front end and a closed rear end. As shown in fig. 4, the motor housing 23 has a front portion 24 located in front of and a rear portion 26 located behind the motor housing 23. The front portion 24 has a shape (outer diameter and inner diameter) substantially equal to the rear end 22 of the gear housing 21. The rear portion 26 has a smaller outer diameter than the front portion 24 and the rear end of the rear portion 26 is closed. A fan 72 fixed to the front end of the motor shaft 711 is disposed in the front portion 24. Most of the motor 71 is disposed at the rear portion 26.

The plurality of guide portions 28 are described with reference to fig. 3, 5, and 10. The plurality of guide portions 28 are configured to guide sliding of the handle 3A with respect to the tool body 2A. In the present embodiment, the guide portions 28 are provided at a plurality of positions on the outer surface of the rear portion 26 in the circumferential direction around the rotation axis A2.

As shown in fig. 3, each guide 28 includes a corner 261 and a guide plate 29. The corner 261 is a corner-shaped portion formed on the left upper and lower portions of the plane P2 and the right upper and lower portions of the plane P2 in the rear portion 26. Each corner 261 extends in the front-rear direction.

The guide plate 29 is a member provided so as to cover the corner 261. In fig. 10, guide portions 28 (guide plates 29) provided at the upper right side and the lower right side of the plane P2 are shown. The guide plate 29 is formed of, for example, a metal material. The 2 guide portions 28 on the left side of the plane P2 and the 2 guide portions 28 on the right side of the plane P2 are symmetrically arranged with respect to the plane P2. Thus, 4 guide portions 28 are provided in the motor housing 23.

As shown in fig. 5 and 10, in the rear portion 26, a front wall 265 and a rear wall 266 orthogonal to the front-rear direction are provided in front of and behind each corner 261. When the handle 3A slides in the front-rear direction, the front wall 265 and the rear wall 266 come into contact with a guide receiving portion 34 (described later) provided in the handle 3A, thereby defining a movement range of the handle 3A in the front-rear direction.

In the present embodiment, the gear housing 21 and the motor housing 23 are fixedly connected to each other. Next, the connection portion of the gear housing 21 and the motor housing 23 will be described.

In fig. 5, a portion of the left side of the plane P2 in the gear housing 21 and the motor housing 23 is shown. Further, the structure of the connecting portion of the gear housing 21 and the motor housing 23 is symmetrical with respect to the plane P2.

The rear end 22 of the gear housing 21 protrudes in a direction away from the plane P2 as compared with other portions of the gear housing 21 (see fig. 5 and 10). Hereinafter, the protruding portions (angular portions) 221, 222, 223, 224 of the rear end portion 22 at the upper left, lower left, upper right, and lower right are also referred to as 1 st connecting portions 221, 222, 223, 224. For example, in fig. 5, the 1 st connection part 221 on the left and the 1 st connection part 222 on the left are shown, and in fig. 10, the 1 st connection part 223 on the right and the 1 st connection part 224 on the right are shown. As illustrated by the 1 st connection portion 222 in fig. 5, holes 61 penetrating the rear end portion 22 in the front-rear direction are provided in the 1 st connection portions 221, 222, 223, 224.

As shown in fig. 3, 5 and 10, the front portion 24 of the motor housing 23 has upper left, lower left, upper right, and lower right corner portions 241, 242, 243, 244 (hereinafter, the 2 nd connecting portions 241, 242, 243, 244) corresponding to the rear end portion 22 of the gear housing 21. The 2 nd connection portions 241, 242, 243, 244 are located immediately behind the 1 st connection portions 221, 222, 223, 224, respectively. In the arrangement of the connection portions, the 1 st connection portions 221 and 223 of the gear housing 21 and the 2 nd connection portions 241 and 243 of the motor housing 23 are located above the plane P1. The 1 st connection portions 222 and 224 of the gear housing 21 and the 2 nd connection portions 242 and 244 of the motor housing 23 are located below the plane P1.

As shown in fig. 5 and 10, rear end portions of the 2 nd connecting portions 242, 244 located at the lower left and lower right are notched toward the plane P2. The notch portions are formed with retainer receiving portions 63L, 63R. Further, grooves into which distal ends of the corrugated members 91 described later can be fitted are formed at rear end portions of the 2 nd connecting portions 241, 243 on the upper left and upper right.

As illustrated by the 2 nd connecting portion 242 in fig. 5, holes 62 that open at least toward the front side and extend in the front-rear direction are provided in the 2 nd connecting portions 241, 242, 243, 244. The hole 62 is a threaded hole. The respective holes 62 of the 2 nd connection portions 241, 242, 243, 244 communicate with the respective holes 61 of the 1 st connection portions 221, 223, 224 in the front-rear direction. In each hole 61, a screw 95 is inserted from the front side (gear housing 21 side) and screwed into the hole 62. Thereby, the gear housing 21 and the motor housing 23 are fixedly connected in the front-rear direction.

As shown in fig. 5, the holes 62 provided at least in the 2 nd connecting portions 242, 244 penetrate in the front-rear direction. In addition, on the 2 nd connecting portions 242, 244, the rear end 952 of the screw 95 is located on the front side of the rear end (opening 622) of the hole 62. The 1 st locking portion 41 of the spring holders 4L, 4R described later is inserted into a region from the opening 622 to the rear end 952 of the screw 95 in the hole 62 provided in the 2 nd connecting portions 242, 244. This region functions as the 2 nd locking portion 621 for locking the spring holders 4L, 4R.

As shown in fig. 3, the holder receiving portions 63L, 63R are disposed below the plane P1 in the front portion 24. The holder receiving portions 63L and 63R are arranged symmetrically with respect to the plane P2 and are separated in the left-right direction. In the present embodiment, the holder receiving portions 63L, 63R are formed by the notch portions of the 2 nd connecting portions 242, 244 and the 2 nd locking portions 621, respectively. In fig. 10, the right cage receiving portion 63R is shown, and in fig. 11, the left cage receiving portion 63L is shown. The holder receiving portions 63L, 63R include a 1 st surface 631 orthogonal to the front-rear direction and a 2 nd surface 632 provided around the 1 st surface 631 rearward of the 1 st surface 631. The rear opening 622 is provided in the 1 st surface 631. The holder receiving portions 63L and 63R can hold the 2 nd biasing springs 52L and 52R via spring holders 4L and 4R described later.

Next, the structure of the handle 3A and its internal structure will be described.

The handle 3A is formed by connecting and fixing a left portion (left housing, left handle portion) 30L and a right portion (right housing, right handle portion) 30R to each other in the left-right direction by screws at a plurality of locations. As shown in fig. 1 and 2, the handle 3A has a cover portion 31 and a grip portion 39.

The cover 31 constitutes an upper portion of the handle 3A. The cover 31 is disposed so as to partially surround the motor case 23. In the present embodiment, the hood 31 covers a portion other than the front end portion of the rear portion 26, and extends to the rear of the rear portion 26.

As shown in fig. 3, the cover 31 has a plurality of guide receiving portions 34. The guide receiving portion 34 is provided on the inner surface of the cover portion 31, in the upper and lower portions on the left side of the plane P2, and on the upper and lower portions on the right side of the plane P2. The guide receiving portions 34 are disposed opposite to the guide portions 28 provided in the rear portion 26, and are configured to engage with the guide portions 28 (guide plates 29). In the present embodiment, each guide receiving portion 34 is formed to be recessed in an angular shape in a direction away from the plane P2 in the inner surface of the cover portion 31, and to extend in the front-rear direction. The guide portion 28 and the guide receiving portion 34 slide relative to each other in response to vibrations generated at the time of machining work, thereby guiding relative movement in the front-rear direction of the handle 3A and the tool body 2A.

The cover portion 31 further has a 1 st spring holding portion 33 and 2 nd spring holding portions 35, 35. These will be described in detail later.

An opening 311 is provided in an upper portion of the cover 31. A part of the opening 311 is disposed on the plane P2. The opening 311 is formed by cutting away the upper wall of the left side portion 30L and the upper wall of the right side portion 30R in a direction away from the plane P2. An operation lever 96 protrudes upward from the opening 311. The lever 96 is connected to the brush unit of the motor 71, and is configured to switch the rotation direction of the motor 71.

Further, a bellows member 91 is disposed between the front portion 24 of the motor housing 23 and the cover portion 31 of the handle 3A. The bellows 91 is an annular member disposed so as to surround the front end portion of the rear portion 26. The bellows 91 is formed so as to be stretchable in the front-rear direction. This prevents dust from entering into the gap between the motor case 23 and the handle 3A.

The grip 39 is a portion gripped by a user. The grip portion 39 extends downward from the cover portion 31 in the up-down direction. Specifically, the upper end 391 of the grip 39 is connected to the rear end of the cover 31, and the lower end (protruding end 392) of the grip 39 is configured as a free end. That is, the grip 39 is supported by the cover 31 in a cantilever manner. The grip 39 may be disposed so as to be offset downward with respect to the drive axis A1 (plane P1). In the present embodiment, the grip 39 is disposed below the motor 71.

As shown in fig. 2, a trigger 92 is disposed at the upper end of the grip portion 39. A switch 93 is disposed behind the trigger 92 in the grip portion 39. The switch 93 is normally kept off, and is turned on in response to a pressing operation of the trigger 92. In response to the turning on of the switch 93, the motor 71 is energized. Further, a power cord 94 connectable to an external ac power supply extends from a lower end 392 (a free end or a protruding end of the handle 3A) of the grip portion 39. In the arrangement of the grip portion 39 of the hammer drill 1A, the grip portion 39 may be described as being arranged below the drive axis A1 or may be described as being arranged below the plane P1. Further, the grip 39 may be described as being disposed below the rotation axis A2. The grip 39 may be described as being disposed below the motor 71.

Next, the connection structure of the tool body 2A and the grip 3A will be described in detail. The tool body 2A and the handle 3A are biased to be separated from each other in the front-rear direction by a plurality of biasing members (1 st biasing spring 51, 2 nd biasing springs 52L, 52R). The hammer drill 1A of the present embodiment is configured such that the force applied to the lower side of the drive axis A1 (the lower side of the plane P1, the side closer to the grip 39) is greater than the force applied to the upper side of the drive axis A1 (the upper side of the plane P1, the side farther from the grip 39).

As shown in fig. 2 to 4, the 1 st biasing spring 51 elastically connects the tool body 2A to the handle 3A on the upper side of the drive axis A1 (on the upper side of the plane P1). In the present embodiment, the 1 st biasing spring 51 is disposed on the plane P2. As shown in fig. 3 to 5, the 2 nd biasing springs 52L, 52R elastically connect the tool body 2A to the handle 3A at a lower side of the drive axis A1 (a lower side of the plane P1). The 2 nd biasing springs 52L, 52R are disposed on the left and right sides of the plane P2, respectively. The 2 nd biasing spring 52L and the 2 nd biasing spring 52R are symmetrical with respect to the plane P2. In the present embodiment, the 1 st biasing spring 51 and the 2 nd biasing springs 52L and 52R are all of the same specification. The springs of the same specification refer to springs of the same shape formed of the same material. Accordingly, the spring constants of the 1 st urging spring 51, the 2 nd urging spring 52L, and the 2 nd urging spring 52R are equal. In the present embodiment, compression coil springs are used as the 1 st biasing spring 51 and the 2 nd biasing springs 52L and 52R.

As shown in fig. 3 and 4, the 1 st biasing spring 51 is disposed between the 1 st spring holding portion 27 provided in the tool body 2A and the 1 st spring holding portion 33 provided in the handle 3A.

In the present embodiment, the 1 st spring holding portion 27 is fixed to an outer surface (upper wall 263, see fig. 3) of the rear portion 26 in the motor housing 23. The 1 st spring holding portion 27 has an abutment surface 271 orthogonal to the front-rear direction and a holding wall 272 provided around the abutment surface 271. The holding wall 272 opens to the right. The 1 st spring holding portion 27 (abutment surface 271) is disposed on the plane P2. The contact surface 271 receives the tip 511 (contacts the tip 511) of the 1 st biasing spring 51.

The 1 st spring holding portion 33 is fixed to the inner surface of the left portion 30L in the cover portion 31. The 1 st spring holding portion 33 has an abutment surface 331 orthogonal to the front-rear direction, and a holding wall 332 opened to the right side and provided around the abutment surface 331. A part of the 1 st spring holding portion 33 (the contact surface 331) is disposed on the plane P2, and is provided rearward (immediately rearward) of the contact surface 271 of the 1 st spring holding portion 27 of the motor case 23. The abutment surface 331 receives the rear end 512 of the 1 st urging spring 51 (abuts against the rear end 512).

The 2 nd biasing springs 52L, 52R are disposed between the spring holders 4L, 4R mounted on the holder receiving portions 63L, 63R of the tool body 2A and the 2 nd spring holding portions 35, 35 provided on the handle 3A, respectively. The spring holders 4L and 4R (left spring holder and right spring holder) are configured to hold the tips 521 and 521 of the 2 nd biasing springs 52L and 52R (left spring and right spring). The 2 nd spring holding portions 35 and 35 are configured to hold the rear ends 522 and 522 of the 2 nd biasing springs 52L and 52R.

The 2 nd biasing spring 52L and the components (the retainer receiving portion 63L, the spring retainer 4L, and the 2 nd spring retaining portion 35) for retaining the 2 nd biasing spring 52L, and the 2 nd biasing spring 52R and the components (the retainer receiving portion 63R, the spring retainer 4R, and the 2 nd spring retaining portion 35) for retaining the 2 nd biasing spring 52R are symmetrically disposed with respect to the plane P2.

The 2 nd spring holding portions 35, 35 are fixed to the front end portion of the cover portion 31, and to the inner walls of the left side portion 30L and the right side portion 30R, respectively. The 2 nd spring holding portions 35, 35 are provided corresponding to the holder receiving portions 63L, 63R of the motor case 23, respectively. As described above, the 2 nd biasing spring 52L and the left-side component that holds the 2 nd biasing spring 52L have the same configuration as the 2 nd biasing spring 52R and the right-side component that holds the 2 nd biasing spring 52R, and therefore, in the following description, the 2 nd biasing spring 52L, the holder receiving portion 63L, the spring holder 4L, and the 2 nd spring holding portion 35 on the left side will be mainly exemplified.

Fig. 4 shows the 2 nd spring holder 35 provided in the left portion 30L. The 2 nd spring holding portion 35 has an abutment surface 351 orthogonal to the front-rear direction and a holding wall 352 provided around the abutment surface 351. The contact surface 351 of the 2 nd spring holding portion 35 receives the rear end 522 (contacts the rear end 522) of the 2 nd urging spring 52L. As shown in fig. 4, the contact surface 351 on which the rear end 522 of the 2 nd urging spring 52L is received is disposed on the front side of the contact surface 331 on which the rear end 512 of the 1 st urging spring 51 is received, and the 2 nd urging springs 52L and 52R are disposed on the front side of the 1 st urging spring 51.

The spring holders 4L, 4R are configured to be connectable to the tool body 2A via holder receiving portions 63L, 63R of the tool body 2A. As shown in fig. 3, the spring holders 4L, 4R are configured to be locked (fitted) to the rear end portions (notched portions of the 2 nd connecting portions 242, 244) of the front portion 24. In fig. 7 and 8, the spring holder 4L and the 2 nd urging spring 52L are illustrated. The spring holder 4L includes an outer wall 42, a support portion 43 fixed to the inner side of the outer wall 42, a rear wall 44, a 1 st locking portion 41, a protruding portion 46, and an engaging portion 45.

The outer wall 42 is formed in a substantially L-shape (angular shape) in cross section. The outer wall 42 has an outer surface 42s, and the outer surface 42s is exposed outside the hammer drill 1A in a state where the spring holder 4L is attached to the holder receiving portion 63L (hereinafter, attached state). As shown in fig. 1, in the mounted state, the outer surface 42s of the spring holder 4L is continuous with the outer surface 24s of the motor housing 23 (front portion 24).

As shown in fig. 8, the support portion 43 is a block portion fixed to a corner portion of the inner surface of the outer wall 42. The support portion 43 has a 1 st surface 431, and the 1 st surface 431 defines a front end of the support portion 43 in a mounted state so as to be orthogonal to the front-rear direction. The 1 st surface 431 is configured to abut against the 1 st surface 631 (see fig. 11) of the holder receiving portion 63L. The rear wall 44 is connected to the rear end of the support portion 43 and is formed orthogonal to the front-rear direction. The rear wall 44 has a front surface 441 located on the front side in the mounted state and a rear surface 442 located on the rear side. As shown in fig. 4, the front surface 441 is configured to abut against the 2 nd surface 632 of the holder receiving portion 63L in the mounted state.

The 1 st locking portion 41 is a convex (cylindrical) portion protruding forward from the 1 st surface 431. As shown in fig. 5, the 1 st locking portion 41 can be inserted into the hole 62 (the 2 nd locking portion 621) from the opening 622 of the holder receiving portion 63L. In the mounted state, the 1 st locking portion 41 is inserted into the 2 nd locking portion 621, and the 1 st surface 431 and the front surface 441 of the spring retainer 4L are respectively abutted against the 1 st surface 631 and the 2 nd surface 632 of the retainer receiving portion 63L.

The protruding portion 46 is a portion protruding rearward from the rear surface 442. As shown by the outline arrows in fig. 6, the tip end portion of the 2 nd biasing spring 52L can be inserted (more specifically, lightly pressed) into the protruding portion 46. When the 2 nd biasing spring 52L is inserted into the protruding portion 46, the spring holder 4L is attached to the holder receiving portion 63L, the front end 521 of the 2 nd biasing spring 52L abuts against the rear surface 442, and the rear end 522 of the 2 nd biasing spring 52L abuts against the abutment surface 351 (see fig. 4 and 5).

The engagement portion 45 is configured to engage with a detaching tool for detaching the spring holder 4L from the tool body 2A. In the present embodiment, the engaging portion 45 is a portion recessed in the outer surface 42s of the spring holder 4L, and is exposed to the outside of the spring holder 4L in the mounted state. The engagement portion 45 is formed in a substantially L-shape so as to follow the shape of the outer wall 42. The detaching tool may be, for example, a tool such as a flat-tip screwdriver, with which the engaging portion 45 can engage. The user can detach the spring holder 4L from the holder receiving portion 63L by engaging the detaching tool with the engaging portion 45 and moving the spring holder 4L rearward so that the spring holder 4L (the 1 st engaging portion 41) is separated from the holder receiving portion 63L (the 2 nd engaging portion 621). Therefore, in the hammer drill 1A of the present embodiment, maintenance such as replacement of the 2 nd biasing springs 52L, 52R can be easily performed.

According to the above-described connection structure, as shown in fig. 4, the 1 st urging spring 51 is interposed in a compressed state between the abutment surface 271 of the 1 st spring holding portion 27 of the motor case 23 and the abutment surface 331 of the 1 st spring holding portion 33 of the cover portion 31. Accordingly, the 1 st urging spring 51 urges the tool body 2A and the handle 3A to be separated from each other in the front-rear direction on the upper side of the drive axis A1 (on the upper side of the plane P1, i.e., on the side away from the grip portion 39).

As shown in fig. 5, the 2 nd biasing spring 52L is interposed in a compressed state between the rear surface 442 of the spring holder 4L mounted on the holder receiving portion 63L of the motor case 23 and the abutment surface 351 of the 2 nd spring holding portion 35 of the cover portion 31 (left side portion 30L). Thus, the 2 nd biasing spring 52L biases the tool body 2A and the handle 3A away from each other in the front-rear direction on the lower side of the drive axis A1 (lower side of the plane P1, i.e., on the side close to the grip 39) and on the left side of the plane P2. Similarly, the 2 nd biasing spring 52R is interposed in a compressed state between the rear surface 442 of the spring holder 4R to which the holder receiving portion 63R of the motor housing 23 is attached and the abutment surface 351 of the 2 nd spring holding portion 35 of the cover portion 31 (right side portion 30R). Thus, the 2 nd biasing spring 52R biases the tool body 2A and the handle 3A away from each other in the front-rear direction on the lower side of the drive axis A1 (lower side of the plane P1, i.e., on the side close to the grip 39) and on the right side of the plane P2. In this way, in the hammer drill 1A, the tips 521 and 521 of the 2 nd urging springs 52L and 52R are held by the tool body 2A via the spring holders 4L and 4R, while the rear ends 522 and 522 of the 2 nd urging springs 52L and 52R are directly held by the left and right side portions 30L and 30R of the handle 3A.

In the present embodiment, the 1 st biasing spring 51 and the 2 nd biasing springs 52L and 52R are disposed between the tool body 2A and the handle 3A in a state where equal initial loads are applied thereto.

The hammer drill 1A described above can be manufactured as follows, for example.

(i) The tool body 2A is prepared.

(ii) One of the left side portion 30L and the right side portion 30R is assembled to the tool body 2A. Specifically, one of the left side portion 30L and the right side portion 30R is disposed so that a portion of the handle 3A corresponding to the cover 31 covers a portion of the motor housing 23.

In the present embodiment, as shown in fig. 9 and 10, the left portion 30L is disposed such that a portion of the left portion 30L corresponding to the cover 31 covers the left outer side of the rear portion 26. In the present embodiment, the left portion 30L is also disposed such that the lever 96 is positioned at a portion of the left portion 30L corresponding to the opening 311. At this time, the tool body 2A and the left portion 30L are placed on a desk or the like such that the outer surface of the left portion 30L is in contact with the desk or the like (i.e., the inner surface of the left portion 30L is directed vertically upward), and components of the handle 3A (for example, the switch 93, the trigger 92, the wiring, and the like) are assembled to the left portion 30L. The 1 st biasing spring 51 is disposed between the 1 st spring holding portion 33 of the left portion 30L and the 1 st spring holding portion 27 of the motor housing 23. More specifically, the front end 511 and the rear end 512 of the 1 st biasing spring 51 are brought into contact with the contact surface 331 of the 1 st spring holding portion 33 and the contact surface 271 of the 1 st spring holding portion 27, respectively.

(iii) Next, the other of the left side portion 30L and the right side portion 30R is assembled to the semi-finished product manufactured by (ii).

In the present embodiment, the inner surface of the right portion 30R is directed downward in the vertical direction, and the right portion 30R and the left portion 30L are abutted in the left-right direction and connected to each other in the left-right direction by screws. When (i) to (iii) are finished, as shown in fig. 11, the portion other than the front end portion in the rear portion 26 of the motor housing 23 is sandwiched by the left side portion 30L and the right side portion 30R.

(iv) The 2 nd biasing spring 52L is disposed between the tool body 2A and the left side portion 30L.

For example, as shown in fig. 7 and 8, the tip end portion of the 2 nd biasing spring 52L is inserted into the protruding portion 46 of the spring holder 4L. More specifically, the tip 521 of the 2 nd biasing spring 52L is lightly pressed into the protruding portion 46 so that the tip 521 of the 2 nd biasing spring 52L abuts against the rear surface 442 of the spring holder 4L. Thereby, the 2 nd biasing spring 52L is held by the spring holder 4L. Then, the rear end 522 of the 2 nd biasing spring 52L held by the spring holder 4L is brought into contact with the contact surface 351 of the 2 nd spring holding portion 35 of the left side portion 30L. At this time, the 2 nd biasing spring 52L is pressed against the contact surface 351 to be compressed, and the spring holder 4L is disposed in the holder receiving portion 63L. More specifically, the 2 nd biasing spring 52L is compressed, and the 1 st locking portion 41 of the spring holder 4L is disposed immediately behind the 2 nd locking portion 621 of the holder receiving portion 63L. In this state, when the compression is released, the 1 st locking portion 41 is locked to the 2 nd locking portion 621, and the spring retainer 4L is arranged in the retainer receiving portion 63L (see fig. 5 and 12).

(v) The 2 nd biasing spring 52R is disposed between the tool body 2A and the right side portion 30R.

The tip end portion of the 2 nd biasing spring 52R is inserted into the protruding portion 46 of the spring holder 4R in the same manner as in (iv) above. Then, the rear end 522 of the 2 nd biasing spring 52R held by the spring holder 4R is brought into contact with the contact surface 351 of the 2 nd spring holding portion 35 of the right side portion 30R. At this time, the 2 nd biasing spring 52R is pressed against the contact surface 351 to be compressed, and the spring holder 4R is disposed in the holder receiving portion 63R. More specifically, the 2 nd biasing spring 52R is compressed, and the 1 st locking portion 41 of the spring holder 4R is disposed immediately behind the 2 nd locking portion 621 of the holder receiving portion 63R. In this state, when the compression is released, the 1 st locking portion 41 is locked to the 2 nd locking portion 621, and the spring retainer 4R is disposed in the retainer receiving portion 63R. Further, the order of the above (iv) and the above (v) may be changed.

As described above, the hammer drill 1A can be manufactured by elastically connecting the tool body 2A and the handle 3A with the 1 st urging spring 51 on the upper side of the drive axis A1 (upper side of the plane P1), and elastically connecting the tool body 2A and the left and right side portions 30L, 30R with the 2 nd urging springs 52L, 52R on the lower side of the drive axis A1 (lower side of the plane P1), respectively.

In the above (i), the bellows member 91 may be attached to the tool body 2A so as to surround the front end portion of the rear portion 26. In the present embodiment, the bellows 91 is made of rubber and is configured to be expandable and contractible in the radial direction. Therefore, by extending the corrugated member 91 in the radial direction, the clearance for performing the above (iv) and (v) can be ensured.

In the hammer drill 1A in which the handle 3A is configured to be separable into the left side portion 30L and the right side portion 30R, the urging springs are disposed (interposed) between the tool body 2A and the left side portion 30L and between the tool body 2A and the right side portion 30R, respectively, a long time may be required in a process of disposing the urging springs by a manufacturer. The reason for this is that when the left side portion 30L and the right side portion 30R are connected in the left-right direction, the inner surface of one of the left side portion 30L and the right side portion 30R faces vertically downward. In this embodiment, since the inner surface of the right side portion 30R is directed downward vertically, the 2 nd biasing spring 52R temporarily held by the right side portion 30R (the 2 nd spring holding portion 35) may fall or be offset from the 2 nd spring holding portion 35 according to the skill of the manufacturer. As described above, the inner surface of the right portion 30R is directed downward in the vertical direction, and the components (the switch 93, the trigger 92) of the handle 3A and the like are disposed on the left portion 30L disposed behind the tool body 2A, so that the inner surface of the left portion 30L is directed upward in the vertical direction, and the green product of the hammer drill 1A is placed on a table or the like.

In addition, from the viewpoint of durability and the like, it is preferable that the urging members (the 1 st urging spring 51, the 2 nd urging springs 52L, 52R) used in the hammer drill 1A are not exposed to the outer surface of the hammer drill 1A. Therefore, the spring holding portion is usually disposed inside the hammer drill (inside the tool body 2A, inside the handle 3A). Therefore, it may take a long time to connect and fix the left side portion 30L and the right side portion 30R in the left-right direction so as to cover the rear of the tool body 2A, and then, to dispose the urging spring between the tool body 2A and the handle 3A.

In contrast, in the present embodiment, as described in (i) to (v) above, the 2 nd biasing springs 52L, 52R can be easily arranged between the tool body 2A and the left side portion 30L of the handle 3A and between the tool body 2A and the right side portion 30R of the handle 3A, respectively, using the spring holders 4L, 4R. Accordingly, the hammer drill 1A can be easily manufactured.

In addition, since the outer surfaces 42s, 42s of the spring holders 4L, 4R are continuous with the outer surface 24s of the tool body 2A in the mounted state, the appearance of the hammer drill 1A can be improved. In addition, the spring holders 4L, 4R are easily aligned with the holder receiving portions 63L, 63R.

The spring holders 4L, 4R (the 1 st locking portion 41) can be locked to the motor housing 23 by the rear portion (the 2 nd locking portion 621) of the hole 62 through which the screw 95 for connecting the gear housing 21 and the motor housing 23 is inserted. Therefore, the structure for locking the spring holders 4L, 4R to the tool body 2A can be simplified.

Further, the hammer drill 1A of the present embodiment has the following advantages.

In the hammer drill 1A in which the tool body 2A and the handle 3A are elastically connected, a machining operation is performed so as to press the grip portion 39 against the workpiece. In the hammer drill 1A in which the grip 39 is displaced downward relative to the drive axis A1 and the lower end 392 of the grip 39 (the handle 3A) is a free end, the user presses the grip 39 into the workpiece during the machining operation, so that the handle 3A (the hammer drill 1A) is easily tilted so that the lower end 392 of the handle 3A approaches the workpiece. In the hammer drill 1A of the present embodiment, 2 urging members (the 2 nd urging springs 52L, 52R) are disposed on the side close to the grip portion 39, and 1 st urging member (the 1 st urging spring 51) is disposed on the side away from the grip portion 39. Therefore, the force on the side closer to the grip 39 is made larger than the force on the side farther from the grip 39. Therefore, the hammer drill 1A can be prevented from tilting so that the lower end 392 of the handle 3A approaches the workpiece during the machining operation. Therefore, the posture of the hammer drill 1A during the machining operation can be stabilized. In other words, the user can perform the machining operation stably.

Further, since the 1 st biasing spring 51 and the 2 nd biasing springs 52L and 52R are of the same specification, the cost due to the stabilization of the machining operation can be suppressed. In addition, as compared with a configuration in which springs of different specifications are used as the 1 st urging spring 51 and the 2 nd urging springs 52L and 52R, confusion at the time of assembly can be prevented.

The 2 nd biasing springs 52L and 52R are disposed on the front side of the 1 st biasing spring 51. Therefore, in comparison with the structure in which the 2 nd biasing springs 52L, 52R are disposed on the rear side of the 1 st biasing spring 51, the grip portion 39 and the 2 nd biasing springs 52L, 52R are separated in the front-rear direction, and therefore the trigger 92 can be disposed at a position in the grip portion 39 (near the upper end 391 of the grip portion 39) close to the drive axis A1. Therefore, the stability of the machining operation and the compactness of the hammer drill 1A can be achieved.

In the hammer drill 1A, the 1 st biasing spring 51 is provided at the substantially center in the left-right direction (on the plane P2), and the 2 nd biasing springs 52L, 52R are provided symmetrically with respect to the plane P2. Therefore, the force acting between the tool body 2A and the handle 3A can be equalized in the left-right direction. Therefore, the machining operation can be stably performed.

Further, since the rear portion 26 of the motor housing 23 is covered with the cover portion 31, tilting of the handle 3A (hammer drill 1A) during the machining operation can be further suppressed. In addition, during the machining operation, vibration mainly occurs in the hammer drill 1A in the driving axis direction (front-rear direction) due to the reaction force from the workpiece by the force of the driving mechanism 75 driving the tip tool 101 and the impact force of the tip tool 101. In the present embodiment, the guide receiving portion 34 of the handle 3A and the guide portion 28 of the motor housing 23 enable the handle 3A to smoothly slide in the front-rear direction with respect to the tool body 2A.

Hereinafter, another mode of making the force on the side closer to the grip 39 larger than the force on the side farther from the grip 39 will be described. In the following, the same reference numerals are used for the same structures as those of the above embodiments, and the description thereof will be omitted.

< embodiment 2 >

In fig. 13, a hammer drill 1B of embodiment 2 is shown. In the hammer drill 1B, 1 st urging spring 51 is disposed above the drive axis A1, and 1 nd urging spring 52B is disposed below the drive axis A1. In the present embodiment, the 1 st biasing spring 51 and the 2 nd biasing spring 52B are springs of different specifications. The spring constant of the 2 nd urging spring 52B is larger than the spring constant of the 1 st urging spring 51.

The hammer drill 1B of the present embodiment has, on the plane P2, a 2 nd spring holding portion 36B that holds the front end 521 of the 2 nd urging spring 52B and a 2 nd spring holding portion 35B that holds the rear end 522 of the 2 nd urging spring 52B. The 2 nd spring holding portion 36B is provided at a lower portion of the motor housing 23. The 2 nd spring holding portion 35B is provided behind the 2 nd spring holding portion 36B and on the inner surface of the cover portion 31. In addition, as in embodiment 1, the initial load of the 1 st urging spring 51 and the 2 nd urging spring 52B is equal.

According to embodiment 2, since the spring constant of the 2 nd urging spring 52B is larger than that of the 1 st urging spring 51, the same number of springs can be disposed on the upper side of the drive axis A1 and the lower side of the drive axis A1, respectively, and the urging force on the side closer to the grip portion 39 can be made larger than the urging force on the side farther from the grip portion 39. Therefore, the hammer drill 1B can be suppressed from tilting during the machining operation. In embodiment 2, since the number of the 2 nd biasing springs 52B is 1, there is an advantage that a space for disposing the plurality of 2 nd biasing springs on the side close to the grip portion 39 is not required.

< embodiment 3 >

In fig. 14, a hammer drill 1C of embodiment 3 is shown. In the hammer drill 1C, 1 st urging spring 51 is disposed above the drive axis A1, and 1 nd urging spring 52C is disposed below the drive axis A1. The 1 st biasing spring 51 and the 2 nd biasing spring 52C are the same size springs as in embodiment 1.

The distance L1 shown in fig. 14 is a distance between the 1 st spring holding portion 27 (abutment surface 271) receiving the front end 511 of the 1 st urging spring 51 and the 1 st spring holding portion 33 (abutment surface 331) receiving the rear end 512 of the 1 st urging spring 51. The distance L2 is a distance between the 2 nd spring holding portion 36B (abutment surface 361) receiving the front end 521 of the 2 nd urging spring 52C and the 2 nd spring holding portion 35C (abutment surface 351) receiving the rear end 522 of the 2 nd urging spring 52C. In the present embodiment, the 2 nd spring holding portion 35C is located in front of the 2 nd spring holding portions 35, 35B of the above embodiment. Therefore, the distance L2 is smaller than the distance L1. That is, the 2 nd biasing spring 52C is assembled to the hammer drill 1C in a state where an initial load larger than that of the 1 st biasing spring 51 is applied.

According to embodiment 3, since the initial load of the 2 nd biasing spring 52C is larger than the initial load of the 1 st biasing spring 51, the same number of springs of the same specification can be disposed on the upper side and the lower side of the drive axis A1, respectively, and the biasing force on the side closer to the grip portion 39 can be made larger than the biasing force on the side farther from the grip portion 39. Therefore, the hammer drill 1C can be suppressed from tilting during the machining operation. In embodiment 3, there is an advantage that a space for disposing the plurality of 2 nd biasing springs on the side close to the grip portion 39 is not required as in embodiment 2. In addition, since the same-sized springs are used as in embodiment 1, the cost due to the stabilization of the machining operation can be suppressed. In addition, as compared with a configuration in which springs of different specifications are used as the 1 st urging spring 51 and the 2 nd urging spring 52C, confusion at the time of assembly can be prevented.

The correspondence between the structure (feature) of the above embodiment and the structure (feature) of the present invention is shown below. However, the configuration (feature) of the embodiment is merely an example, and the configuration (feature) of the present invention or the present embodiment is not limited thereto.

The hammer drills 1A, 1B, 1C are examples of "impact tools". The 1 st biasing spring 51 is an example of a "1 st biasing member". The 2 nd biasing springs 52L, 52R, 52B, 52C are examples of "the 2 nd biasing member".

< other embodiments >

The impact tool according to the present invention is not limited to the hammer drills 1A, 1B, and 1C of the above embodiments. For example, the following illustrative non-limiting modifications can be applied. At least 1 of these modifications may be adopted in combination with at least 1 of the hammer drills 1A, 1B, 1C and the configurations (features) described in the claims.

The number of the urging springs is not limited to the above-described embodiment. For example, the number of 1 st urging springs on the upper side of the drive axis A1 may be 2 or more, and the number of 2 nd urging springs on the lower side of the drive axis A1 may be 3 or more. For example, the 2 1 st biasing springs 51, 51 may be disposed on the left side of the plane P2 and the right side of the plane P2, respectively, similarly to the 2 nd biasing springs 52L, 52R of the above embodiment. In this case, the front ends 511, 511 of the 1 st biasing springs 51, 51 may be connected to the tool body 2A via the spring holders 4L, 4R, and the rear ends 522, 522 may be directly connected to the left and right side portions 30L, 30R. According to this aspect, the hammer drill can be easily manufactured in the same manner as in the above embodiment.

The spring holders 4L, 4R may be connected to the handle 3A instead of the tool body 2A. For example, the 2 nd urging spring 52L may be connected to the left side portion 30L via the spring holder 4L, and directly connected (held) to the tool body 2A. Also, the 2 nd urging spring 52R may be connected to the right side portion 30R via the spring holder 4R, and directly connected (held) to the tool body 2A. Alternatively, the 2 nd urging spring 52L may be connected to the left side portion 30L via the spring holder 4L and directly connected to the tool body 2A, and on the other hand, the 2 nd urging spring 52R may be connected to the tool body 2A via the spring holder 4R and directly connected to the right side portion 30R. According to this aspect, the hammer drill can be easily manufactured in the same manner as in the above embodiment.

Further, from the viewpoint of suppressing the hammer drills 1A, 1B, and 1C from tilting so that the handle 3A approaches the workpiece during the machining operation, it is preferable to adjust the (1) number, (2) initial load, and (3) spring constant of at least 1 st and at least 1 st 2 nd apply springs so that the force of the 1 st apply spring on the upper side of the drive axis A1 is smaller than the force of the 2 nd apply spring on the lower side of the drive axis A1. In the case where the urging force of the 1 st urging spring on the upper side of the drive axis A1 and the urging force of the 2 nd urging spring on the lower side of the drive axis A1 do not reach the targeted set values by adjusting any one of (1) to (3), 2 or all 3 of (1) to (3) can be combined.

The urging members that urge the tool body 2A and the handle 3A in the direction to separate from each other in the front-rear direction are not limited to the 1 st urging spring 51 and the 2 nd urging springs 52L, 52R, 52B, 52C. For example, a spring (e.g., an extension coil spring, a leaf spring, a torsion spring, etc.) different from the kind of the compression coil spring may be employed. Alternatively, an elastic member other than a spring such as rubber or synthetic resin may be used as the urging member. The structures of the spring holders 4L, 4R, the holder receiving portions 63L, 63R, the 1 st spring holding portions 27, 33, and the 2 nd spring holding portions 35, 35B, 35C, 36B may be changed as appropriate according to the type, position, and the like of the biasing member to be used.

In the above-described embodiments, the hammer drills 1A, 1B, 1C are illustrated as the impact tools, and the features of the present invention can also be applied to other electric tools capable of performing an impact operation (for example, electric hammers capable of performing only an impact operation without performing a rotation operation). In addition, the hammer drill 1A may have only 2 operation modes of the impact mode and the rotation mode. The structure and arrangement of the motor 71 and the driving mechanism 75 can be appropriately changed according to the impact tool to which the features of the present invention are applied. For example, the motor 71 may employ a direct current motor (e.g., a brushless DC motor). In this case, for example, a battery mounting portion for a rechargeable battery (also referred to as a battery pack) may be provided in the tool body 2A or the handle 3A.

In view of the above-described embodiments, the present invention is constructed as follows. At least 1 of the following modes can be adopted in combination with at least 1 of the configurations (features) described in the above-described embodiments and modifications thereof, and the respective aspects.

Modes 1 to 1

The axis of rotation of the motor extends parallel to the drive axis on the underside of the drive axis,

the grip portion is disposed below the rotation axis.

Modes 1 to 2

The axis of rotation of the motor extends parallel to the drive axis on the underside of the drive axis,

the grip portion is disposed below the motor.

Modes 1 to 3

The cover portion at least partially encloses the motor housing in a circumferential direction about the rotational axis.

Modes 1 to 4

The motor housing has a plurality of guide portions configured to guide the handle in such a manner that the handle moves relative to the tool body along the drive axis,

the cover portion has a plurality of guide receiving portions arranged at positions corresponding to the guide portions.

Modes 1 to 5

The plurality of guide portions have a left guide portion located on the left side of the imaginary plane and a right guide portion located on the right side of the imaginary plane,

The plurality of guide receiving portions have a left guide receiving portion located on the left side of the virtual plane and a right guide receiving portion located on the right side of the virtual plane.

Modes 1 to 6

The handle has a left side portion and a right side portion connected to each other in a left-right direction orthogonal to the front-rear direction and the up-down direction,

the at least 1 2 nd urging member includes a left side spring and a right side spring,

the left side spring is arranged between the left side portion and the tool body,

the right side spring is disposed between the right side portion and the tool body.

Modes 1 to 7

The impact tool further includes a left spring holder connected to one of the tool body and the left portion, and a right spring holder connected to one of the tool body and the right portion,

the left spring is disposed between the tool body and the left spring holder,

the right spring is disposed between the tool body and the right spring holder.

Further, as a non-limiting 1 object of providing a technique for facilitating improvement of arrangement of a plurality of urging members in an impact tool having a tool main body, a handle which can be divided into left and right side portions, and a plurality of urging members, the following modes 2-1 to 2-11 can be provided. The following modes 2-1 to 2-11 may employ only any 1 or a combination of more than 2. Alternatively, at least 1 of the following modes 2-1 to 2-11 may be employed in combination with at least 1 of the hammer drills 1A, 1B, and 1C of the embodiments, the modification examples described above, modes 1-1 to 1-7, and the features described in the respective modes.

Mode 2-1

An impact tool configured to drive a tip tool in a straight line, wherein,

comprises a motor, a driving mechanism, a tool body, a handle, a 1 st spring, a 2 nd spring and a 1 st spring retainer,

the driving mechanism is configured to drive the tip tool along a driving axis defining a front-rear direction of the impact tool by power of the motor;

the tool main body accommodates the motor and the driving mechanism and extends in the front-rear direction;

the handle includes a grip portion extending in a vertical direction orthogonal to the front-rear direction behind the tool body, and is formed of a 1 st portion and a 2 nd portion connected to each other in a left-right direction orthogonal to the front-rear direction and the vertical direction;

the 1 st spring is disposed between the tool body and the 1 st portion, and is configured to apply force to the tool body and the handle so as to be separated from each other in the front-rear direction;

the 2 nd spring is disposed between the tool body and the 2 nd portion, and is configured to apply a force to the tool body and the handle so as to be separated from each other in the front-rear direction;

The 1 st spring holder is configured to hold the 1 st spring and is configured to be connectable to one of the tool body and the 1 st portion,

the 1 st spring and the 2 nd spring have a 1 st end and a 2 nd end respectively,

the 1 st end of the 1 st spring is connected to one of the tool body and the 1 st part via the 1 st spring holder, and the 2 nd end of the 1 st spring is directly connected to the other of the tool body and the 1 st part.

According to the impact tool of embodiment 2-1, in the impact tool in which the handle is formed of the 2 split bodies including the 1 st and 2 nd portions, the 1 st and 2 nd springs are elastically connected to the tool body and the 2 nd and 2 nd portions, respectively, so that the handle can be biased with good balance between the left and right. Therefore, the vibration transmitted from the tool body to the handle during the machining operation can be reduced with good balance between the left and right. Therefore, the operability of the impact tool can be improved. Further, since the 1 st spring is connected to one of the tool body and the 1 st portion via the 1 st spring holder and is directly connected to the other, transmission of vibration can be reduced without providing one of the tool body and the 1 st portion with a structure for locking the spring.

Mode 2-2

In the impact tool of mode 2-1,

the 1 st end of the 1 st spring is connected to the tool body via the 1 st spring holder,

the 2 nd end of the 1 st spring is directly connected to the 1 st portion.

According to embodiment 2-2, the 1 st spring can be connected to the tool body via the 1 st spring holder.

Modes 2 to 3

In the impact tool of mode 2-2,

the 1 st spring retainer has a 1 st locking part,

the tool body has a 2 nd locking portion configured to be locked with the 1 st locking portion of the 1 st spring holder.

According to the embodiment 2-3, the 1 st spring holder can be connected to the tool body by locking the 1 st locking portion to the 2 nd locking portion.

Modes 2 to 4

In the impact tool described in mode 2-3,

the tool body has a gear housing accommodating the driving mechanism and a motor housing accommodating the motor at the rear of the gear housing,

the gear shell is connected with the motor shell by a screw,

a part of the hole provided in the motor housing for inserting the screw functions as the 2 nd locking portion,

the 1 st locking portion of the 1 st spring retainer has a convex portion configured to engage with a part of the hole.

According to aspects 2 to 4, the 1 st spring retainer can be locked to the tool body by using the hole of the motor housing for connection with the gear housing.

Modes 2 to 5

In the impact tool according to any one of modes 2-1 to 2-4,

the outer surface of the 1 st spring holder is continuous with the outer surface of one of the tool body and the handle.

According to aspects 2 to 5, the appearance of the impact tool can be improved.

Modes 2 to 6

The impact tool according to any one of aspects 2-1 to 2-5, further comprising a 2 nd spring holder,

the 2 nd spring holder is configured to hold the 2 nd spring and is configured to be connectable to one of the tool body and the 2 nd portion,

the 1 st end of the 2 nd spring is connected to one of the tool body and the 2 nd portion via the 2 nd spring holder,

said 2 nd end of said 2 nd spring being directly connected to the other of said tool body and said 2 nd portion,

the 1 st spring holder and the 1 st spring, and the 2 nd spring holder and the 2 nd spring are disposed below the drive axis.

According to aspects 2 to 6, the force on the side closer to the grip portion can be increased as compared with a structure in which the 1 st spring and the 2 nd spring are arranged above the drive axis. Therefore, the handle can be prevented from tilting so that the lower end of the grip portion approaches the workpiece during the machining operation.

Further, the 2 nd spring holder may have the same structure as the 1 st spring holder. In addition, in the manner in which the 2 nd spring holder is connected to the tool body, the portion of the tool body to which the 2 nd spring holder is connected may have the same structure as the portion of the tool body to which the 1 st spring holder is connected.

Modes 2 to 7

In the impact tool according to any one of modes 2-1 to 2-6,

the tool body includes a motor housing that houses the motor disposed at a rear portion of the tool body,

the handle comprises a cover portion at least partially surrounding the motor housing,

the upper end of the holding part is connected to the cover part.

According to modes 2 to 7, the motor housing can be covered with the handle, and the handle can be biased with good left-right balance.

Modes 2 to 8

In the impact tool according to any one of modes 2-1 to 2-7,

the 1 st spring holder has an engaging portion exposed outside the 1 st spring holder and configured to engage with a detaching tool for detaching the 1 st spring holder from one of the tool body and the handle.

According to aspects 2 to 8, the 1 st spring holder can be detached from one of the tool body and the handle, and the 1 st spring can be easily replaced. Therefore, the impact tool can be easily repaired.

Modes 2 to 9

In the impact tool according to any one of modes 2-1 to 2-8,

the impact tool has an operation handle configured to be capable of switching a rotation direction of the motor, and is manually operable by a user,

the cover portion has an opening, at least a part of which is arranged on an imaginary plane including the drive axis and extending in the up-down direction, and is formed by connecting the 1 st portion and the 2 nd portion in the left-right direction,

the operating handle is connected to the motor in an operable manner and protrudes from the opening to the outside.

Modes 2 to 10

A method of manufacturing an impact tool having a tool body, a handle, a 1 st spring, and a 2 nd spring, wherein,

the tool body extends in the front-rear direction, houses a motor and a driving mechanism configured to drive the tip tool along a driving axis defining the front-rear direction of the impact tool;

the handle includes a grip portion extending in a vertical direction orthogonal to the front-rear direction behind the tool body, and is formed of a 1 st portion and a 2 nd portion connected to each other in a left-right direction orthogonal to the front-rear direction and the vertical direction;

The 1 st spring and the 2 nd spring are configured to apply force to the tool main body and the handle so as to be separated from each other in the front-rear direction,

the method has a 1 st procedure and a 2 nd procedure, wherein,

in the step 1, the rear part of the tool body is held by the 1 st part and the 2 nd part, and the 1 st part and the 2 nd part are connected;

in the 2 nd step, after the 1 st step, the 1 st spring is compressed and assembled between the tool body and the 1 st part, and the 2 nd spring is compressed and assembled between the tool body and the 2 nd part, and the tool body and the handle are elastically connected.

According to modes 2 to 10, the following impact tool can be manufactured: the handle is configured to be divided into a 1 st part and a 2 nd part, and the 1 st spring and the 2 nd spring are disposed (interposed) between the tool body and the 1 st part and between the tool body and the 2 nd part, respectively.

Modes 2 to 11

In the method described in modes 2 to 10,

the impact tool further has a 1 st spring holder and a 2 nd spring holder, wherein the 1 st spring holder is connected to one of the tool body and the 1 st portion; the 2 nd spring holder is connected to one of the tool body and the 2 nd portion,

In the 2 nd step of the method, the method comprises the following steps:

the 1 st spring is connected to the other of the tool body and the 1 st part and is connected to the one of the tool body and the 1 st part via the 1 st spring holder,

the 2 nd spring is connected to one of the tool body and the 2 nd portion via the 2 nd spring holder, and to the other of the tool body and the 2 nd portion.

According to modes 2 to 11, the 1 st spring holder and the 2 nd spring holder can be used, and the 1 st spring and the 2 nd spring can be disposed between the tool body and the 1 st portion and between the tool body and the 2 nd portion, respectively. Therefore, the impact tool can be easily manufactured.

The correspondence between each component (feature) of modes 2-1 to 2-11 and each component (feature) of the present invention or the embodiment is shown below. However, the constituent elements of the embodiment are merely examples, and are not limited to the constituent elements of embodiments 2-1 to 2-11.

The hammer drills 1A, 1B, 1C are examples of "impact tools". The right side portion 30R and the left side portion 30L are examples of "1 st portion" and "2 nd portion". The spring holders 4R and 4L are examples of "1 st spring holder" and "2 nd spring holder". The 2 nd biasing spring 52R and the 2 nd biasing spring 52L are examples of "1 st spring" and "2 nd spring". The front end 521 and the rear end 522 are examples of "1 st end" and "2 nd end". (i) (ii) (iii) is an example of "step 1". (iv) and (v) are examples of "step 2".

In the hammer drill 1A, one of the left side portion 30L and the right side portion 30R can be elastically connected to the tool body 2A by the 2 nd urging spring via the spring holder, and the other of the left side portion 30L and the right side portion 30R can be elastically connected to the tool body 2A by the 2 nd urging spring without via the spring holder. For example, in the above embodiment, in the step (iii) of connecting the left side portion 30L and the right side portion 30R in the left-right direction, the inner surface of the left side portion 30L faces vertically upward, and the inner surface of the right side portion 30R faces vertically downward. Therefore, after the step (iii), if the 2 nd biasing spring 52R is disposed by using the spring holder 4R at least between the right portion 30R and the tool body 2A, the 2 nd biasing spring 52R can be prevented from falling down or being offset from the 2 nd spring holding portion 35, and the hammer drill 1A can be easily manufactured. In this case, a spring holder for receiving the tip 511 of the 2 nd biasing spring 52L is provided in place of the holder receiving portion 63R in the tool body 2A, and the tool body 2A and the left portion 30L are placed on a table or the like to assemble the components of the handle 3A to the left portion 30L (ii), and at this time, the 2 nd biasing spring 52L may be compressed and assembled between the spring holder and the 2 nd spring holder 35 of the left portion 30L.

Claims (14)

1. An impact tool configured to drive a tip tool in a straight line, characterized in that,

comprising a motor, a driving mechanism, a tool body, a handle and a plurality of force application components, wherein,

the driving mechanism is configured to drive the tip tool along a driving axis defining a front-rear direction of the impact tool by power of the motor;

the tool main body accommodates the motor and the driving mechanism and extends in the front-rear direction;

the handle includes a grip portion extending in an up-down direction orthogonal to the front-rear direction in the rear of the tool body, the grip portion having a lower end formed as a free end and being disposed below the drive axis;

the plurality of urging members are configured to elastically connect the tool body and the handle, urge the tool body and the handle to be separated from each other in the front-rear direction,

the plurality of force application members have:

at least 1 st force application member arranged above the drive axis in the up-down direction; and

at least 1 2 nd force applying members arranged below the drive axis in the up-down direction,

the force of the at least 1 2 nd force applying member is greater than the force of the at least 1 st force applying member.

2. The impact tool of claim 1, wherein the impact tool comprises a plurality of blades,

the at least 1 st force application component and the at least 1 2 nd force application component are all of the same specification,

the number of the at least 1 st force application member 2 is greater than the number of the at least 1 st force application member 1.

3. An impact tool as claimed in claim 1 or 2, characterized in that,

the number of the at least 1 st force applying members is 1,

the number of the at least 1 2 nd urging members is 2.

4. An impact tool as claimed in claim 3, wherein,

the 2 nd urging members are symmetrically disposed with respect to an imaginary plane including the drive axis and extending in the up-down direction.

5. An impact tool as claimed in claim 1, claim 3 as directly dependent on claim 1, or claim 4 as directly dependent on claim 3 as dependent on claim 1,

the spring constant of the at least 1 2 nd urging member is larger than the spring constant of the at least 1 st urging member.

6. The impact tool as claimed in any one of claims 1 to 5, wherein,

the at least 1 2 nd force applying member is disposed between the tool body and the handle in a state where an initial load larger than that of the at least 1 st force applying member is applied.

7. The impact tool as claimed in any one of claims 1 to 6, wherein,

the at least 1 2 nd urging member is provided in front of the at least 1 st urging member.

8. The impact tool as claimed in any one of claims 1 to 7, wherein,

the tool body includes a motor housing disposed at a rear portion of the tool body for accommodating the motor,

the handle comprises a cover portion at least partially surrounding the motor housing,

the upper end of the holding part is connected to the cover part.

9. The impact tool of claim 8, wherein the impact tool comprises a plurality of blades,

the cover portion at least partially encloses the motor housing in a circumferential direction about the rotational axis.

10. The impact tool of claim 9, wherein the impact tool comprises a plurality of blades,

the motor housing has a plurality of guide portions configured to guide the handle in such a manner that the handle moves relative to the tool body along the drive axis,

the cover portion has a plurality of guide receiving portions arranged at positions corresponding to the plurality of guide portions.

11. The impact tool of claim 10, wherein the impact tool comprises a plurality of blades,

The plurality of guide portions have a left guide portion located on the left side of an imaginary plane including the drive axis and extending in the up-down direction and a right guide portion located on the right side of the imaginary plane,

the plurality of guide receiving portions have a left guide receiving portion located on the left side of the virtual plane and a right guide receiving portion located on the right side of the virtual plane.

12. The impact tool as claimed in any one of claims 1 to 11, wherein,

the axis of rotation of the motor extends parallel to the drive axis on the underside of the drive axis,

the grip portion is disposed below the rotation axis.

13. The impact tool of claim 12, wherein the impact tool comprises a plurality of blades,

the grip portion is disposed below the motor.

14. The impact tool as claimed in any one of claims 1 to 13, wherein,

the handle has a left side portion and a right side portion connected to each other in a left-right direction orthogonal to the front-rear direction and the up-down direction,

the at least 12 nd urging member includes a left side spring and a right side spring,

the left side spring is arranged between the left side portion and the tool body,

The right side spring is disposed between the right side portion and the tool body.