Impact tool

Abstract

The present invention provides an impact tool which drives a tip tool linearly along a driving axis, the impact tool having a tool body which defines the driving axis, a motor housed in the tool body, an elongated handle cantileveredly connected to the tool body and extending in a direction intersecting the driving axis, and at least one force applying member interposed between the tool body and the handle. The motor has a motor shaft rotatable about an axis parallel to the driving axis. The handle includes a first end portion rotatably connected to the tool body about a rotational axis relative to the tool body, and a grip portion configured to be positioned between the first end portion and a free end of the handle for a user to grip. The at least one force applying member applies a force to the tool body and the handle to rotate the same away from the tool body toward the grip portion. Accordingly, it is possible to reduce vibrations transmitted to the grip portion in the impact tool.

Description

TECHNICAL FIELD

[0001] The present application relates to an impact tool configured to drive a tip tool in a straight line. BACKGROUND

[0002] In an impact tool that performs a work on a workpiece by driving a tip tool in a straight line along a driving axis, particularly large vibrations occur in the extension direction of the driving axis. In this regard, various anti-vibration housing structures have been proposed. For example, in an impact tool (hammer drill) disclosed in Patent Literature 1, a handle is elastically connected to a main body portion that houses a motor and a driving mechanism in a manner movable in the extension direction of the driving axis. The relative movement of the main body portion and the handle is guided by sliding a first guide member provided to the outer surface of a cylindrical motor housing portion of the main body portion and a second guide member provided to the inner side surface of a cylindrical housing portion of the handle disposed outside the motor housing portion.

[0003] [Patent Literature]

[0004] [Patent Literature]

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2015-100897 SUMMARY

[0006] [Problems to be Solved by the Invention]

[0007] According to the structure disclosed in Patent Literature 1, it is possible to effectively suppress the transmission of vibrations in the extension direction of the driving axis from the main body portion to the handle. On the other hand, there is room for further improvement in terms of alleviating the transmission of vibrations to the grip portion held by the user.

[0008] An object of the present application is to provide a technology that contributes to alleviating vibrations transmitted to a grip portion in an impact tool.

[0009] According to one embodiment of the present application, an impact tool configured to drive a tip tool in a straight line along a driving axis. The impact tool has a tool main body, a motor, a handle, and at least one urging member. The tool main body defines the driving axis. The motor is housed in the tool main body. The motor has a motor shaft rotatable about an axis parallel to the driving axis. The handle is formed in an elongated shape, connected to the tool main body in a cantilevered manner, and extends in a direction intersecting the driving axis. The handle includes a first end portion and a grip portion. The first end portion is connected to the tool main body in a manner rotatable about a rotation axis relative to the tool main body. The grip portion is configured to be positioned between the first end portion and a free end of the handle for being held by a user. The at least one urging member is positioned between the tool main body and the handle, and applies a rotational urging force to the tool main body and the handle in a direction in which the grip portion and the tool main body are distanced from each other.

[0010] According to the above-described structure, the handle is turned relative to the tool body in response to the vibration generated during driving of the tip tool, and the at least one force receiving member absorbs the vibration, whereby the vibration transmitted from the tool body to the handle can be reduced. In addition, by providing the turning axis at the first end portion, the relative movement amount of the grip portion relative to the tool body can be increased as compared with the case where the turning axis is provided at the grip portion, so that the effect of reducing the vibration transmitted to the grip portion is improved. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a left view of the hammer drill according to the first embodiment, showing the handle in the initial position.

[0012] Figure 2 is an exploded view of the tool body and the handle.

[0013] Figure 3 is a partial enlarged view of Figure 1

[0014] Figure 4 is a IV-IV sectional view of Figure 3

[0015] Figure 5 is a V-V sectional view of Figure 3

[0016] Figure 6 is a partial left view of the hammer drill, showing the handle in the forward position.

[0017] Figure 7 is a VII-VII sectional view of Figure 6

[0018] Figure 8 is a left view of the hammer drill according to the second embodiment, showing the handle in the initial position.

[0019] Figure 9 is a partial left view of the hammer drill, showing the handle in the initial position, with the left side member of the handle removed.

[0020] Figure 10 is a partial right view of the hammer drill, showing the handle in the initial position, with the right side member of the handle removed.

[0021] Figure 11 is an XI-XI sectional view of Figure 8

[0022] Figure 12 is a partial left view of the hammer drill, showing the handle in the forward position, with the left side member of the handle removed.

[0023] REFERENCE NUMERALS​​​​​

[0024] 1A, 1B: hammer drill; 2A, 2B: tool body; 21: motor housing portion; 23: drive mechanism housing portion; 25: extension portion; 250: plate portion; 251: circular plate portion; 255: locking portion; 26: first connecting portion; 260: support hole; 261: recess; 28: first spring holding portion; 281: spring receiving portion; 282: abutting surface; 283: end surface; 285: spring guide portion; 3A, 3B: handle; 301: left side member; 302: right side member; 30: upper end portion; 31: cover portion; 315: abutting portion; 32: second connecting portion; 321: connecting shaft; 33: grip portion; 331: trigger; 332: stop portion; 335: switch; 337: power cord; 37: second spring holding portion; 370: opening; 371: spring receiving portion; 373: abutting surface; 374: locking piece; 376: stop portion; 377: stop surface; 378: restriction portion; 41: elastic member; 43: urging spring; 431: first end portion; 432: second end portion; 44: urging spring; 440: coil portion; 441: first end portion; 442: second end portion; 71: motor; 711: motor shaft; 75: drive mechanism; 79: tool holder; 91: tip tool; Al: drive axis; A2: rotation axis; A3: turning axis. DETAILED DESCRIPTION

[0025] In one or more embodiments of the present application, the drive axis can be located between the turning axis and the grip portion in the extension direction of the handle. According to this structure, the handle is more likely to rotate with respect to the tool body in response to vibration in the extension direction of the drive axis (hereinafter referred to as the drive axis direction) of the tool body, thereby further improving the effect of reducing transmission of vibration.

[0026] In one or more embodiments of the present application, at least a portion of the grip portion can also be located on a straight line that intersects the turning axis and extends in a direction orthogonal to the drive axis. According to this structure, the moving direction of the grip portion accompanying relative rotation of the handle appropriately corresponds to the drive axis direction, and transmission of vibration in the drive axis direction to the grip portion can be effectively reduced.

[0027] In one or more embodiments of the present application, the position of the turning axis can also be variable. According to this structure, transmission of vibration in each direction can be effectively reduced.

[0028] In one or more embodiments of the present application, the tool body and the handle can also be connected so as to be relatively movable in a direction intersecting the rotation axis, by at least one elastic member interposed between the tool body and the first end portion of the handle around the rotation axis. In other words, the tool body and the first end portion of the handle can also be elastically connected by at least one elastic member. According to this structure, transmission of vibration in the direction intersecting the rotation axis can be effectively reduced. Also, the tool body and the handle can also be connected so as to be relatively movable in an extension direction of the rotation axis, by at least one elastic member. According to this structure, transmission of vibration in the direction intersecting the rotation axis and in the extension direction of the rotation axis can be effectively reduced without increasing the number of components.

[0029] In one or more embodiments of the present application, the handle can be formed of a first member and a second member connected to each other in an extension direction of the rotation axis. Also, the at least one elastic member can include a first elastic member interposed between the tool body and the first member, and a second elastic member interposed between the tool body and the second member. According to this structure, the two elastic members can be easily disposed in balance in the extension direction of the rotation axis.

[0030] In one or more embodiments of the present application, the at least one force applying member can be at least one spring. Also, the at least one spring can be disposed so that a force applying direction thereof coincides with an extension direction of a tangent of a circle centered on the rotation axis. According to this structure, a spring optimal for relative rotation of the tool body and the handle is realized.

[0031] In one or more embodiments of the present application, the at least one force applying member can include two springs disposed in balance with respect to a plane including the rotation axis and extending in the extension direction of the handle. According to this structure, relative rotation of the tool body and the handle can be stabilized compared to a case where one spring is provided.

[0032] In one or more embodiments of the present application, the at least one force applying member can be at least one helical torsion spring disposed around the rotation axis. According to this structure, a holding structure of the at least one helical torsion spring can be made relatively simple and compact.

[0033] Hereinafter, representative and non-limiting embodiments of the present application will be specifically described with reference to the accompanying drawings.

[0034] <First Embodiment>

[0035] Reference Figures 1-7The hammer drill 1A according to the first embodiment will be described. The hammer drill 1A is an example of an electric tool (so-called an impact tool) that can drive the tip tool 91 in a linear manner by impacting it. More specifically, the hammer drill 1A is an electric tool that can perform an action of driving the tip tool 91 in a linear manner along a predetermined drive axis A1 (hereinafter also referred to as an impact action) and an action of driving the tip tool 91 in a rotational manner about the drive axis A1 (hereinafter referred to as a rotational action).

[0036] like Figure 1 As shown, the outer contour of the hammer drill 1A is mainly formed by the tool body 2A and the handle 3A connected to the tool body 2A.

[0037] The tool body 2A is a hollow body that houses the main mechanism of the hammer drill 1A, and is also referred to as the main body shell, outer contour shell, etc. The tool body 2A extends along the drive axis A1 of the top tool 91. A tool holder 79 is disposed in one end of the tool body 2A in the extension direction of the drive axis A1 (hereinafter referred to as the drive axis direction). The top tool 91 can be detachably mounted on the tool holder 79. The tool body 2A mainly houses a motor 71 and a drive mechanism 75, which is configured to drive the top tool 91 held in the tool holder 79 by the power of the motor 71. In this embodiment, the motor 71 is configured such that the rotation axis A2 of the motor shaft 711, which rotates integrally with the rotor, extends parallel to the drive axis A1.

[0038] The handle 3A is an elongated, hollow body that cantileveredly connects to the other end of the tool body 2A in the direction of the drive axis (i.e., the end opposite to the end where the tool holder 79 is located). In other words, only one end of the handle 3A in the direction of its long axis is connected to the tool body 2A, and the other end of the handle 3A is a free end. Furthermore, the hammer drill 1A is a pistol-type handheld tool. The handle 3A protrudes from the other end of the tool body 2A in a direction intersecting the drive axis A1 (more specifically, in a direction substantially orthogonal to the drive axis A1 and the rotation axis A2). The handle 3A has a trigger 331 that is pressed (pulled) by the user. In the hammer drill 1A, in response to the pressing of the trigger 331, the motor 71 is energized, and the drive mechanism 75 is driven, thereby performing an impact action and / or a rotational action.

[0039] The detailed structure of the hammer drill 1A will now be described. For convenience, in the following description, the extension direction of the drive axis A1 (the long axis 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 where the tool holder 79 is located is defined as the front side of the hammer drill 1A, and the opposite side (the side connected to the handle 3A) is defined as the rear side. The direction orthogonal to the drive axis A1 and corresponding approximately to the extension direction of the handle 3A (the direction orthogonal to both the drive axis A1 and the rotation axis A2) is defined as the vertical direction of the hammer drill 1A. In the vertical direction, the side where the handle 3A is connected to the tool body 2A is defined as the upper side of the hammer drill 1A, and the protruding end side of the handle 3A is defined as the lower side of the hammer drill 1A. Furthermore, the direction orthogonal to both the front-rear and vertical directions is defined as the left-right direction of the hammer drill 1A.

[0040] First, the structure of the main body 2A of the tool and its internal structure will be explained.

[0041] like Figures 1-5 As shown, the tool body 2A includes a motor housing 21, a drive mechanism housing 23, an extension 25, and two first spring retaining parts 28.

[0042] The motor housing 21 is the part that houses the motor 71. The motor housing 21 constitutes the rear half of the tool body 2A. The motor housing 21 is formed into a cylindrical shape with a closed rear end.

[0043] The drive mechanism housing 23 houses the drive mechanism 75. The drive mechanism housing 23 forms the front half of the tool body 2A. The front end of the drive mechanism housing 23 is cylindrical, and a tool holder 79 is disposed inside it. The drive mechanism 75 includes a motion conversion mechanism for performing impact actions and an impact mechanism, and a rotation transmission mechanism for performing rotational actions. Since these are well-known structures, detailed illustrations and descriptions are omitted. The motion conversion mechanism typically employs a mechanism that converts rotational motion into linear motion using a swash bearing (e.g., a wobble plate / bearing) or a crankshaft mechanism and piston. The rotation transmission mechanism typically employs a reduction gear mechanism comprising multiple gears.

[0044] Furthermore, in this embodiment, the hammer drill 1A has three operating modes: an impact mode (hammering only), a rotation mode (rotation only), and a rotation-impact mode (hammering with rotation). The drive mechanism 75 operates according to the operating mode selected by the user via the mode switching knob. Since these are well-known structures, detailed illustrations and descriptions are omitted.

[0045] The extension 25 is an elongated portion extending above the motor housing 21 along the drive axis direction (i.e., the front-to-back direction). The rear end of the extension 25 (i.e., the upper rear end of the tool body 2A) is elastically connected to the handle 3A (specifically, the second connecting portion 32) via an elastic member 41. Therefore, the rear end of the extension 25 will be referred to below as the first connecting portion 26. The connection structure between the first connecting portion 26 and the second connecting portion 32 will be described in detail later.

[0046] Two first spring retaining portions 28 are respectively provided at the left and right rear ends of the motor housing portion 21. Each first spring retaining portion 28 is configured to receive (bear) the first end 431 of the two ends of the force-applying spring 43 (aggregating to the first end 431). Furthermore, in this embodiment, the force-applying spring 43 is a helical compression spring. The force-applying spring 43, in a compressed state, lies between the first spring retaining portion 28 and the handle 3A (more specifically, the spring receiving portion 371 of the second spring retaining portion 37), applying force to the tool body 2A and the handle 3A in a direction that moves them away from each other. That is, the first spring retaining portion 28 is elastically connected to the handle 3A (more specifically, the second spring retaining portion 37) via the force-applying spring 43. The connection structure between the first spring retaining portion 28 and the second spring retaining portion 37 will be described in detail later.

[0047] Next, the structure and internal structure of the handle 3A will be explained.

[0048] like Figure 4 As shown, in this embodiment, the handle 3A is formed by connecting and fixing the left component (left housing, left handle part) 301 and the right component (right housing, right handle part) 302 together with screws in multiple locations along the left-right direction.

[0049] In addition, such as Figures 1-5 As shown, the handle 3A includes a cover 31, a second connecting part 32, a gripping part 33, and two second spring retaining parts 37.

[0050] The cover 31 forms the upper part of the handle 3A. The cover 31 is configured to cover the rear end of the tool body 2A (more specifically, the rear end of the motor housing 21 and the first connecting part 26). More specifically, the cover 31 includes a left wall, a right wall, a rear wall, and an upper wall respectively disposed on the left, right, rear, and upper sides of the rear end of the tool body 2A.

[0051] The second connecting part 32 is provided at the upper end of the cover part 31 (i.e., the upper end 30 of the handle 3A) and is connected to the first connecting part 26 of the tool body 2A via the elastic member 41. The detailed structure of the second connecting part 32 and the connection method with the first connecting part 26 will be described in detail later.

[0052] The grip portion 33 is a portion to be gripped by the user. The grip portion 33 extends downward from the cover portion 31. That is, the grip portion 33 extends in the vertical direction at a position lower than the lower end of the tool body 2A. The grip portion 33 is an elongated cylindrical portion. A trigger 331 is provided at the upper end portion of the grip portion 33. Inside the grip portion 33, a switch 335 is provided behind the trigger 331. The switch 335 is normally kept in an off state, and is turned on in response to a pressing operation of the trigger 331. In response to the switch 335 being turned on, the motor 71 is energized. In addition, a power supply cord 337 capable of being connected to an external alternating current power supply extends from the lower end of the grip portion 33 (the free end, the protruding end of the handle 3A).

[0053] The two second spring holding portions 37 are provided in correspondence with the left and right first spring holding portions 28 of the tool body 2A, respectively. The second spring holding portions 37 are each configured to receive (bear) the second end portion 432 of the two end portions of the urging spring 43 (abut against the second end portion 432). The connection structure of the first spring holding portion 28 and the second spring holding portion 37 will be described later in detail.

[0054] Next, details of the connection structure of the tool body 2A and the handle 3A will be described.

[0055] First, details of the connection structure of the first connection portion 26 and the second connection portion 32 will be described.

[0056] As described above, Figure 2 and Figure 4 The extension portion 25 of the tool body 2A includes a plate-shaped portion 250 and two circular plate portions 251. The plate-shaped portion 250 is formed in an elongated rectangular plate shape, and extends linearly in the front-rear direction. The two circular plate portions 251 protrude to the left and right, respectively, from the rear end portion of the plate-shaped portion 250. The first connection portion 26 is formed by the two circular plate portions 251 and the portion of the plate-shaped portion 250 located between the two circular plate portions 251 (the rear end portion of the plate-shaped portion 250).

[0057] The first connection portion 26 has a support hole 260. The support hole 260 is an opening having a circular cross section that penetrates the first connection portion 26 in the left-right direction. In addition, the support hole 260 penetrates the central portions of the circular plate portions 251. In addition, annular recesses 261 are formed in the side surfaces of the respective circular plate portions 251 in a manner so as to surround the periphery of the support hole 260. Annular elastic members 41 (elastic rings) are embedded in the respective recesses 261. In the present embodiment, the elastic members 41 are formed of silicone rubber.

[0058] On the other hand, as described above, Figure 4As shown, the second connecting portion 32 of the handle 3A has a connecting shaft 321. Further, as described above, in the present embodiment, the handle 3A is formed of a left side member 301 and a right side member 302. The connecting shaft 321 is formed by a first portion provided to the left side member 301 and a second portion provided to the right side member 302 being fixed to each other by a screw. The connecting shaft 321 extends in the left-right direction between the left wall portion and the right wall portion of the cover portion 31 in the upper end portion 30 of the handle 3A.

[0059] The diameter of the connecting shaft 321 is smaller than the diameter of the support hole 260 of the first connecting portion 26. The connecting shaft 321 is inserted in the support hole 260 and is supported by the two elastic members 41. One of the two elastic members 41 intervenes between the left end portion of the connecting shaft 321 (the first portion of the left side member 301) and the first connecting portion 26 in the radial direction of the connecting shaft 321. The other of the two elastic members 41 intervenes between the right end portion of the connecting shaft 321 (the second portion of the right side member 302) and the first connecting portion 26. The two elastic members 41 hold the connecting shaft 321 and the first connecting portion 26 in a state of being separated from each other in the radial direction of the connecting shaft 321.

[0060] Further, one of the two elastic members 41 intervenes between the left wall portion of the cover portion 31 (the left side member 301) and the first connecting portion 26 (the circular plate portion 251) in the axial direction (the left-right direction) of the connecting shaft 321. The other of the two elastic members 41 intervenes between the right wall portion of the cover portion 31 (the right side member 302) and the first connecting portion 26 (the circular plate portion 251). The two elastic members 41 hold the left side member 301 and the right side member 302 and the first connecting portion 26 in a state of being separated from each other in the left-right direction, respectively.

[0061] With this connecting structure, the connecting shaft 321 (and the handle 3A) is able to rotate relative to the first connecting portion 26 (and the tool main body 2A) about the rotational axis A3 with the axis of the connecting shaft 321 as the rotational axis A3. Further, the connecting shaft 321 (and the handle 3A) is able to move relative to the first connecting portion 26 (and the tool main body 2A) in a direction intersecting the rotational axis A3 and in the extension direction (the left-right direction) of the rotational axis A3 in response to the elastic deformation of the elastic members 41. That is, in the present embodiment, the position of the rotational axis A3 relative to the tool main body 2A (and the driving axis A1) is able to change in response to the elastic deformation of the elastic members 41. Further, in the description of the present embodiment, it is always described that "the rotational axis A3 extends in the left-right direction", but this description can also include a case where the rotational axis A3 is slightly shifted from the strict left-right direction.

[0062] Next, the connecting structure of the first spring holding portion 28 and the second spring holding portion 37 will be described.

[0063] AsFigure 2 and Figure 5 As shown in FIG. 1, the two first spring holding portions 28 of the tool body 2A are symmetrically arranged with respect to an imaginary plane P extending in the up-down direction (substantial extension direction of the handle 3A) through the center of the left-right direction (extension direction of the rotation axis A3) of the hammer drill 1A (tool body 2A). Further, the plane P can also be said to be an imaginary plane P including the drive axis Al and extending in the up-down direction (plane P including the drive axis Al and the rotation axis A2). The first spring holding portions 28 each include a spring receiving portion (spring seat) 281 and a spring guide portion 285.

[0064] The spring receiving portion 281 is formed in a stepped cylindrical shape including a small diameter portion and a large diameter portion, and is fixed to the outer surface of the motor housing portion 21. The spring receiving portion 281 is arranged below and forward with respect to the first connecting portion 26. The central axis of the spring receiving portion 281 is inclined with respect to the drive axis Al and the rotation axis A2 of the motor shaft 711. More specifically, the central axis of the spring receiving portion 281 is inclined downward as it goes toward the rear. The spring receiving portion 281 is arranged with the small diameter portion located obliquely rearward and downward of the large diameter portion. The first end portion 431 of the biasing spring 43, which is a coil spring, is fitted over the small diameter portion of the spring receiving portion 281, and abuts against an abutting surface 282 of a shoulder portion (step portion at the boundary between the small diameter portion and the large diameter portion) of the spring receiving portion 281.

[0065] The spring guide portion 285 extends obliquely rearward and downward adjacent to the small diameter portion of the spring receiving portion 281. The spring guide portion 285 has a curved surface corresponding to the outer peripheral shape of the biasing spring 43. The spring guide portion 285 guides the expansion and contraction of the biasing spring 43 while suppressing movement of the biasing spring 43 in a direction intersecting the axis.

[0066] As shown in FIG. 1, the two first spring holding portions 28 of the tool body 2A are symmetrically arranged with respect to an imaginary plane P extending in the up-down direction (substantial extension direction of the handle 3A) through the center of the left-right direction (extension direction of the rotation axis A3) of the hammer drill 1A (tool body 2A). Further, the plane P can also be said to be an imaginary plane P including the drive axis Al and extending in the up-down direction (plane P including the drive axis Al and the rotation axis A2). The first spring holding portions 28 each include a spring receiving portion (spring seat) 281 and a spring guide portion 285. Figures 2-5 As shown in FIG. 1, the two first spring holding portions 28 of the tool body 2A are symmetrically arranged with respect to an imaginary plane P extending in the up-down direction (substantial extension direction of the handle 3A) through the center of the left-right direction (extension direction of the rotation axis A3) of the hammer drill 1A (tool body 2A). Further, the plane P can also be said to be an imaginary plane P including the drive axis Al and extending in the up-down direction (plane P including the drive axis Al and the rotation axis A2). The first spring holding portions 28 each include a spring receiving portion (spring seat) 281 and a spring guide portion 285.

[0067] The spring receiving portion 371 is a wall portion that defines the short side of the lower rear of the opening 370 and is disposed at a position lower and rearward than the spring receiving portion 281 of the first spring retaining portion 28. The spring receiving portion 371 has an abutting surface 373 that abuts against the second end portion 432 of the biasing spring 43. The abutting surface 373 substantially faces the abutting surface 282 of the spring receiving portion 281 of the first spring retaining portion 28. In addition, two locking pieces 374 protrude from the spring receiving portion 371. The second end portion 432 of the biasing spring 43 is held in between the two locking pieces 374.

[0068] The stop portion 376 is a wall portion that defines the short side of the upper front of the opening 370 and has a stop surface 377 that can abut against the end surface 283 of the spring receiving portion 281 (large diameter portion). The stop surface 377 of the stop portion 376 extends substantially in parallel with the abutting surface 373 of the spring receiving portion 371.

[0069] The two restriction portions 378 are wall portions that define the two long sides of the opening 370. The restriction portions 378 prevent the intermediate portion of the biasing spring 43 from being excessively bent when the tool body 2A and the handle 3A are relatively rotated.

[0070] The biasing spring (helical compression spring) 43 is held in a compressed state between the spring receiving portion 281 (abutting surface 282) of the tool body 2A (first spring retaining portion 28) and the spring receiving portion 371 (abutting surface 373) of the handle 3A (second spring retaining portion 37) and exerts a force on the tool body 2A and the handle 3A to rotate them. More specifically, the biasing spring 43 exerts a force on the handle 3A relative to the tool body 2A to rotate the handle 3A in a direction in which the gripping portion 33 is moved away from the tool body 2A (counterclockwise direction in FIG. 6). Hereinafter, this direction is referred to as the first direction. The first direction can also be referred to as a direction in which the free end of the handle 3A is moved rearward relative to the tool body 2A or a direction in which the angle (angle formed by the driving axis Al and the long axis of the handle 3A) between the tool body 2A and the gripping portion 33 is increased. Figure 3

[0071] In the initial state, the handle 3A is held at a position where the stop surface 377 of the stop portion 376 abuts against the end surface 283 of the spring receiving portion 281 by the force of the biasing spring 43. Figure 3 Figure 5 ​​(As shown in the image). The initial state refers to the state in which there is no external force acting to resist the force of the force-applying spring 43, causing the handle 3A to rotate relative to the tool body 2A in the opposite direction (i.e., the direction in which the gripping part 33 moves closer to the tool body 2A; hereinafter referred to as the second direction). The second direction can also be referred to as the direction in which the free end of the handle 3A moves forward relative to the tool body 2A, or the direction in which the angle between the tool body 2A and the gripping part 33 decreases. Hereinafter, the position of the handle 3A relative to the tool body 2A in the initial state will be referred to as the initial position of the handle 3A.

[0072] like Figure 3 As shown, in this embodiment, the force-applying spring 43 is configured such that when the handle 3A is in the initial position, the axis of the force-applying spring 43 (i.e., the direction of force application and extension of the force-applying spring 43) is approximately aligned with the extension direction of the tangent T of the circle centered on the rotation axis A3 of the handle 3A (i.e., the direction of rotation of the handle 3A relative to the tool body 2A). Furthermore, when the hammer drill 1A is viewed from the left or right, the upper end of the grip 33 (the part where the trigger 331 is located) lies on an imaginary straight line L (more specifically, an imaginary straight line substantially orthogonal to the drive axis A1, the rotation axis A2, and the rotation axis A3) that intersects the rotation axis A3 and extends in the vertical direction.

[0073] On the other hand, in response to applying an external force to the handle 3A, such as Figure 6 and Figure 7 As shown, the handle 3A can rotate in a second direction relative to the tool body 2A while compressing the force spring 43 (overcoming the force of the force spring 43). In this embodiment, a limiting part 332 is provided at the upper end of the trigger 331. The limiting part 332 is a protrusion that protrudes upward from the trigger 331. When the handle 3A is in the initial position ( Figure 3 When the handle 3A is in the position shown, the limiting part 332 is positioned downwards from the lower end of the tool body 2A (specifically, the motor housing 21). The handle 3A can rotate relative to the tool body 2A in the second direction from its initial position to a position where the limiting part 332 abuts against the lower end of the tool body 2A. Figure 6 The position shown is referred to below as the forward position. Additionally, the upper end of the grip 33 is also located on the straight line L when the handle 3A is in the forward position.

[0074] The functions of the tool body 2A and handle 3A during the impact action are explained below.

[0075] When the driving mechanism 75 performs the impact action, the tool main body 2A generates the greatest vibration in the driving axis direction (front-rear direction) by driving the tip tool 91 along the driving axis Al. In response to this vibration, the handle 3A is rotated relative to the tool main body 2A in the range between the initial position and the front position while receiving the force of the first direction of the urging spring 43, and the grip portion 33 is relatively moved in the front-rear direction. In addition, the urging spring 43 absorbs the vibration by extending and contracting in response to the relative rotation of the tool main body 2A and the handle 3A. Accordingly, the transmission of the vibration from the tool main body 2A to the handle 3A in the driving axis direction is effectively reduced. In particular, the axis of the urging spring 43 is disposed in the direction of the relative rotation of the tool main body 2A and the handle 3A, and the disposition of the urging spring 43 is optimized. In addition, the two urging springs 43 are disposed symmetrically with respect to the plane P in the extension direction of the rotation axis A3 (left-right direction), and thus the tool main body 2A and the handle 3A can be stably rotated relative to each other.

[0076] In the hammer drill 1A, the rotation axis A3 of the handle 3A is provided at the upper end portion 30 of the handle 3A which is apart upward from the grip portion 33. According to this structure, compared with the case where the rotation axis A3 is provided at the grip portion 33, the amount of movement of the grip portion 33 relative to the tool main body 2A in the front-rear direction can be increased, and the effect of reducing the transmission of the vibration in the front-rear direction to the grip portion 33 can be improved. In addition, in the known impact tool, there is an impact tool in which the cylindrical rear end portion of the tool main body and the cylindrical upper end portion of the handle which covers the periphery of the rear end portion of the tool main body are elastically connected in a manner that they can slide in the driving axis direction (front-rear direction). In such an impact tool, the vibration-proof effect of the grip portion which is located below the cylindrical portion of the handle is sometimes slightly reduced compared with the cylindrical portion of the handle. According to the structure of the present embodiment, the vibration-proof effect of the grip portion 33 can be more reliably improved compared with the cover portion 31 (upper end portion 30) of the handle 3A.

[0077] Further, in the extension direction of the handle 3A, the driving axis Al is located between the rotation axis A3 of the handle 3A and the grip portion 33. According to this structure, compared with the case where the driving axis Al is located at a position higher than the rotation axis A3, the handle 3A is easily rotated relative to the tool main body 2A in response to the vibration in the front-rear direction of the tool main body 2A. Thus, the transmission effect of the vibration in the front-rear direction is improved.

[0078] In addition, the upper end portion of the grip portion 33 (the portion corresponding to the trigger 331) is located on a straight line L which intersects the rotation axis A3 and extends in the up-down direction. According to this structure, the moving direction of the grip portion 33 at the time of the relative rotation of the handle 3A is appropriately in the front-rear direction. Thus, the transmission effect of the vibration in the front-rear direction is improved.

[0079] Further, in the hammer drill 1A, the elastic member 41 disposed around the rotation axis A3 (the connecting shaft 321) allows the tool body 2A and the handle 3A to relatively move in all directions intersecting the rotation axis A3 by elastic deformation. Further, the elastic member 41 also allows the tool body 2A and the handle 3A to relatively move in the direction of extension of the rotation axis A3 (i.e., the left-right direction) by elastic deformation. That is, in the present embodiment, the tool body 2A and the handle 3A are allowed to not only rotate around the rotation axis A3 but also relatively move in the front-rear direction by the elastic member 41. Therefore, the transmission of the maximum vibration in the front-rear direction is further effectively reduced. In addition, the tool body 2A also generates vibrations in other directions (e.g., the up-down direction, the left-right direction) that are not as large as the vibrations in the front-rear direction. The connecting structure using the elastic member 41 of the present embodiment is also able to appropriately cope with vibrations in all directions other than the front-rear direction in response to the elastic deformation of the elastic member 41.

[0080] Further, in the present embodiment, two elastic members 41 are respectively disposed between the tool body 2A and the left side member 301 of the handle 3A and between the tool body 2A and the right side member 302 of the handle 3A. According to this structure, when the tool body 2A and the handle 3A (the left side member 301 and the right side member 302) are assembled, the two elastic members 41 can be easily disposed in balance in the left-right direction. In addition, the relative movement of the tool body 2A and the handle 3A can be stabilized.

[0081] <2nd Embodiment>

[0082] Hereinafter, the hammer drill 1B according to the 2nd embodiment will be described with reference to the drawings. Figures 8-12 The hammer drill 1B according to the 2nd embodiment will be described. Further, the hammer drill 1B according to the 2nd embodiment includes structures common to the hammer drill 1A according to the 1st embodiment (refer to Figure 1 ). Therefore, hereinafter, structures substantially the same as those of the hammer drill 1A (including cases where the shapes are slightly different) in the hammer drill 1B will be denoted by the same reference numerals, and the description will be omitted or simplified, and mainly the different structures will be described.

[0083] As shown in Figure 8 , the hammer drill 1B according to the 2nd embodiment, like the hammer drill 1A according to the 1st embodiment, has a tool body 2B and a handle 3B elastically connected to the tool body 2B. However, the connecting structure of the tool body 2B and the handle 3B is different from that of the 1st embodiment, and the details will be described later.

[0084] The tool body 2B includes a motor housing portion 21 housing the motor 71, a drive mechanism housing portion 23 housing the drive mechanism 75, and an elongated extension portion 25 extending in the front-rear direction above the motor housing portion 21. The rear end portion of the extension portion 25 is configured as a 1st connecting portion 26 (refer to Figure 11 ).

[0085] Figures 9-11 As shown, the handle 3B is formed by the left member (left housing) 301 and the right member (right housing) 302 being connected and fixed to each other in the left-right direction by screws (omitted from the drawing) as in the first embodiment. In addition, the handle 3B includes a cover portion 31 that covers the rear end portion of the tool body 2B, a second connecting portion 32 that is elastically connected to the first connecting portion 26, and a grip portion 33 that has a trigger 331.

[0086] Next, the connecting structure of the tool body 2B and the handle 3B will be described in detail.

[0087] As shown, in the present embodiment, as in the first embodiment, the first connecting portion 26 of the tool body 2B and the second connecting portion 32 of the handle 3B are connected by two elastic members 41. That is, the elastic members 41 are respectively located between the connecting shaft 321 and the first connecting portion 26 in the radial direction of the connecting shaft 321. In addition, the elastic members 41 are respectively located between the left member 301 and the first connecting portion 26 and between the right member 302 and the first connecting portion 26 in the axial direction (left-right direction) of the connecting shaft 321. Figure 11 According to this connecting structure, the connecting shaft 321 (and the handle 3A) is able to rotate relative to the first connecting portion 26 (and the tool body 2A) about the rotational axis A3 with the axis of the connecting shaft 321 as the rotational axis A3. In addition, the tool body 2B and the handle 3B are also able to move relative to the first connecting portion 26 (and the tool body 2A) in a direction intersecting the rotational axis A3 and in the extension direction (left-right direction) of the rotational axis A3 in response to elastic deformation of the elastic members 41.

[0088] As shown, in the present embodiment, the tool body 2B and the handle 3B are rotationally urged in a direction in which the grip portion 33 and the tool body 2B are distanced from each other by the urging spring 44. In the present embodiment, the urging spring 44 is not a helical compression spring but a helical torsion spring.

[0089] Figures 9-11 The coil portion 440 of the urging spring 44 is disposed around the circular plate portion 251 on the right side of the first connecting portion 26 (the rear end portion of the extension portion 25). A locking portion 255 that protrudes upward is provided at the upper rear end portion of the extension portion 25 (in front of the circular plate portion 251). The first end portion 441 of the urging spring 44 is locked in a locking groove formed in the locking portion 255. In addition, an abutting portion 315 is provided at the rear wall portion of the cover portion 31 of the handle 3B (in detail, the right member 302). The second end portion 442 of the urging spring 44 abuts against the front surface of the abutting portion 315.

[0090] The coil portion 440 of the urging spring 44 is disposed around the circular plate portion 251 on the right side of the first connecting portion 26 (the rear end portion of the extension portion 25). A locking portion 255 that protrudes upward is provided at the upper rear end portion of the extension portion 25 (in front of the circular plate portion 251). The first end portion 441 of the urging spring 44 is locked in a locking groove formed in the locking portion 255. In addition, an abutting portion 315 is provided at the rear wall portion of the cover portion 31 of the handle 3B (in detail, the right member 302). The second end portion 442 of the urging spring 44 abuts against the front surface of the abutting portion 315. ​

[0091] The force applying spring (helical torsion spring) 44 applies a force to the handle 3B to rotate it in the first direction (counterclockwise direction in the drawing) with respect to the tool body 2B in a state where the first end 441 is caught in the catching portion 255 and the second end 442 abuts against the abutting portion 315. Figure 9 In the initial state, the handle 3B is held in an initial position (position shown by the dotted line in the drawing) where the limiting portions (not shown in the drawing) provided in the tool body 2B and the handle 3B abut against each other by the force of the force applying spring 44. On the other hand, the handle 3B rotates in the second direction (clockwise direction in the drawing) opposite to the first direction with respect to the tool body 2B in response to an external force being applied, like Figure 9 the handle 3B rotates in the second direction (clockwise direction in the drawing) opposite to the first direction with respect to the tool body 2B in response to an external force being applied, like Figure 12 the handle 3B rotates in the second direction (clockwise direction in the drawing) opposite to the first direction with respect to the tool body 2B in response to an external force being applied, like

[0092] The operation of the tool body 2B and the handle 3B at the time of the impact in the present embodiment is substantially the same as that of the tool body 2A and the handle 3A in the first embodiment. Therefore, in the present embodiment, too, the transmission of the vibration from the tool body 2B to the handle 3B is effectively reduced as described above.

[0093] Further, in the present embodiment, the force applying spring 44 is a helical torsion spring and is disposed around the rotation axis A3 (the circular plate portion 251). According to this structure, the tool body 2A and the handle 3A can be appropriately forced to rotate by providing the catching portion 255 and the abutting portion 315 in the tool body 2A and the handle 3A, respectively. Thus, in the present embodiment, a comparatively simple and compact structure for holding the force applying spring 44 is realized. In addition, according to the structure of the present embodiment, the force applying spring 44 is also easy to assemble.

[0094] The correspondence between the structures (features) of the above-described embodiments and the structures (features) of the present application will be shown below. However, the structures (features) of the embodiments are only examples and do not limit the present application or the structures (features) of the present application.

[0095] The hammer drills 1A and 1B are examples of "percussion tools". The drive axis Al is an example of "drive axis". The tool bodies 2A and 2B are examples of "tool body". The motor 71 is an example of "motor". The motor shaft 711 is an example of "motor shaft". The rotation axis A2 is an example of "axis of motor shaft". The handles 3A and 3B are examples of "handle". The upper end portions 30 of the handles 3A and 3B are examples of "first end portion". The rotation axis A3 is an example of "rotation axis". The gripping portions 33 are examples of "gripping portion". The urging springs 43 are examples of "urging member", and are examples of "spring". Further, the urging springs 44 are another examples of "urging member", and are examples of "spring" and "helical torsion spring". The elastic members 41 are examples of "elastic member". The left side portions 301 of the handles 3A and 3B are examples of "first member", and the right side portions 302 are examples of "second member".

[0096] Further, the above-described embodiments are merely examples, and the percussion tools according to the present application are not limited to the hammer drills 1A and 1B. For example, the following non-limiting modifications can be added. Further, at least one of these modifications can be used in combination with at least one of the hammer drills 1A and 1B and the structures (features) described in the technical solutions.

[0097] In the above-described embodiments, the hammer drills 1A and 1B are examples of the percussion tools, but the features of the present application can also be applied to other electric power tools capable of performing a percussion action (for example, an electric hammer capable of performing only a percussion action without a rotation action). Further, the hammer drills 1A and 1B can have only two action modes of a percussion mode and a rotation mode. The structures and arrangements of the motor 71 and the drive mechanism 75 can be appropriately changed in accordance with the percussion tools to which the features of the present application are applied.

[0098] The connection structures of the tool bodies 2A and 2B to the handles 3A and 3B can be appropriately changed. For example, instead of the above-described first connection portions 26 and second connection portions 32, shafts protruding to the left and right, respectively, can be provided at the rear end portions of the tool bodies 2A and 2B, and recesses can be formed in the left and right wall portions of the upper end portions 30 of the handles 3A and 3B, respectively. Further, annular elastic members 41 can be inserted into the recesses, and the shafts of the tool bodies 2A and 2B can be supported by the elastic members 41. Instead of the annular elastic members 41, a plurality of elastic members can be arranged around the connection shaft 321. Further, the rear end portions of the tool bodies 2A and 2B and the upper end portions 30 of the handles 3A and 3B can be connected by a single elastic member in a manner that the tool bodies 2A and 2B and the handles 3A and 3B are relatively rotatable about the rotation axis A3 and relatively movable in at least one of the front-rear direction, the up-down direction, and the left-right direction. Further, the elastic members 41 and the modified elastic members are not limited to silicone rubber, and for example, other kinds of rubber, various synthetic resins capable of elastically deforming, and various springs can be appropriately used.

[0099] Also, the rear end portion of the tool body 2A, 2B and the upper end portion 30 of the handle 3A, 3B are not necessarily connected by the elastic members, but can be directly connected in a relatively rotatable manner. For example, the connecting shaft 321 can also be supported in a rotatable manner in a state where the outer peripheral surface thereof is in contact with the surface defining the support hole 260. That is, the position of the rotation axis A3 can also be substantially unchangeable.

[0100] In the above-described embodiments, the handle 3A, 3B is formed by two split bodies (left side member 301 and right side member 302) connected to each other in the left-right direction. However, the handle 3A, 3B can also be formed by split bodies divided in the front-rear direction, for example, connected to each other. Alternatively, the handle 3A, 3B can also be formed by a plurality of members divided in other directions connected to each other. Also, the constituent members of the tool body 2A, 2B and the manner of connection thereof can be appropriately changed.

[0101] In addition, the elastic members that apply a rotational force to the tool body 2A, 2B and the handle 3A, 3B in a direction in which the gripping portion 33 and the tool body 2A, 2B are distanced from each other are not limited to the biasing springs 43, 44. For example, instead of the biasing springs 43, 44, a leaf spring, a coil spring, a belleville spring, or the like can be employed. Alternatively, an elastic member other than a spring, such as rubber or synthetic resin, can also be employed. In addition, the number and position of the biasing springs 43, 44 are not limited to those exemplified in the above-described embodiments. For example, the biasing spring 43 of the first embodiment can be provided only one on the plane P. Alternatively, the biasing spring 43 can be provided three or more. The biasing spring 44 of the second embodiment can also be provided two around the left and right circular plate portions 251. In addition, the structure of the spring receiving portion that receives the end portions of the biasing springs 43, 44 can be appropriately changed in accordance with the kind, position, and the like of the spring employed.

[0102] The hammer drill 1A, 1B can also be configured to operate by power supplied from a battery (also referred to as a battery pack) of a charging type, rather than power supplied from an external alternating-current power source. In this case, for example, a battery mounting portion in which the battery can be detachably mounted is provided at the lower end portion (free end portion) of the handle 3A, 3B.

[0103] Also, the following modes are constituted in view of the gist of the present application. At least one of the following modes can be used in combination with at least one of the features described in the above-described embodiments, examples, modified examples, and technical solutions.

[0104] [Mode 1] The extending direction of the drive axis defines the front-rear direction of the impact tool,

[0105] a direction orthogonal to the driving axis and the axis of the motor shaft defines a top-bottom direction of the impact tool,

[0106] The first end portion is an upper end portion of the handle, and is connected to a rear end portion of the tool body in a manner rotatable about the rotation axis.

[0107] [Mode 2] The gripping portion is located lower than the tool body in the top-bottom direction.

[0108] [Mode 3] The rotation axis extends substantially along a left-right direction orthogonal to the front-rear direction and the top-bottom direction.

[0109] [Mode 4] An upper end portion of the gripping portion has an operation member configured to be pressed by the user.

[0110] The trigger 331 of the above embodiment is an example of the "operation member" of the present mode.

[0111] [Mode 5] The upper end portion of the gripping portion is located on a straight line intersecting the rotation axis and extending in the top-bottom direction.

[0112] [Mode 6] The at least one elastic member is configured to allow relative movement of the tool body and the handle in the extension direction of the driving axis.

[0113] [Mode 7] The elastic member is formed in a ring shape (elastic ring).

[0114] [Mode 8] One of the tool body and the first end portion of the handle has a shaft,

[0115] The at least one elastic member is disposed around the shaft, between the shaft and the other of the tool body and the first end portion.

[0116] The connecting shaft 321 of the above embodiment is the "shaft" of the present mode.

[0117] [Mode 9] The spring is a helical compression spring extending along an axis, and is disposed such that the axis is substantially aligned with the extension direction of the tangent line.

Claims

1. An impact tool configured to drive a tip tool linearly along a driving axis, characterized by comprising: a tool body, a motor, a handle, and at least one force applying member, wherein the tool body defines the driving axis; the motor is housed in the tool body and has a motor shaft rotatable about an axis parallel to the driving axis; the handle is an elongated handle cantileveredly connected to the tool body and extending in a direction intersecting the driving axis, and includes a first end portion rotatably connected to the tool body about a rotation axis, and a grip portion positioned between the first end portion and a free end of the handle for a user to grip; and the force applying member is interposed between the tool body and the handle and applies a rotational force to the tool body and the handle in a direction to separate the grip portion and the tool body from each other, wherein the rotation axis is variable in position relative to the tool body or the driving axis, and the tool body and the handle are connected in a manner relatively movable in a direction intersecting the rotation axis by at least one elastic member interposed between the tool body and the first end portion of the handle around the rotation axis, and the at least one elastic member is arranged in a manner to be clamped by the tool body and the handle in an extension direction of the rotation axis, and the tool body and the handle are connected in a manner relatively movable also in the extension direction of the rotation axis by the at least one elastic member.

2. An impact tool configured to drive a tip tool linearly along a driving axis, characterized by comprising: a tool body, a motor, a handle, and at least one force applying member, wherein the tool body defines the driving axis; the motor is housed in the tool body and has a motor shaft rotatable about an axis parallel to the driving axis; the handle is an elongated handle cantileveredly connected to the tool body and extending in a direction intersecting the driving axis, and includes a first end portion rotatably connected to the tool body about a rotation axis, and a grip portion positioned between the first end portion and a free end of the handle for a user to grip; and the force applying member is interposed between the tool body and the handle and applies a rotational force to the tool body and the handle in a direction to separate the grip portion and the tool body from each other, wherein the at least one force applying member is at least one spring arranged so that a force applying direction of the at least one spring is substantially coincident with an extension direction of a tangent to a circle centered on the rotation axis and inclined relative to the driving axis.

3. An impact tool configured to drive a tip tool linearly along a driving axis, characterized by comprising: a tool body, a motor, a handle, and a helical torsion spring, wherein the tool body defines the driving axis; the motor is housed in the tool body and has a motor shaft rotatable about an axis parallel to the driving axis; the handle is an elongated handle cantileveredly connected to the tool body and extending in a direction intersecting the driving axis, and includes a first end portion rotatably connected to the tool body about a rotation axis, and a grip portion positioned between the first end portion and a free end of the handle for a user to grip; and the helical torsion spring is interposed between the tool body and the handle and applies a rotational force to the tool body and the handle in a direction to separate the grip portion and the tool body from each other. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The motor is housed in the tool body, and has a motor shaft that is rotatable about an axis parallel to the drive axis; The handle is an elongated handle that is cantileveredly connected to the tool body and extends in a direction intersecting the drive axis, and includes a first end portion and a grip portion, wherein the first end portion is connected to the tool body so as to be rotatable about a rotation axis relative to the tool body, and the grip portion is configured to be positioned between the first end portion and a free end of the handle, for a user to grip; The helical torsion spring is interposed between the tool body and the handle, and applies a rotational biasing force to the tool body and the handle in a direction in which the grip portion and the tool body are distanced from each other, The helical torsion spring has a coil portion that is disposed around the rotation axis, a first end portion that applies a biasing force to the tool body, and a second end portion that applies a biasing force to the handle, One of the tool body and the first end portion of the handle has a shaft, The other of the tool body and the first end portion of the handle has a cylindrical portion that is disposed around the shaft, The tool body and the handle are connected so as to be relatively movable in a direction intersecting the rotation axis and in an extension direction of the rotation axis, by at least one elastic ring that is interposed between the shaft and the cylindrical portion around the rotation axis and in a radial direction of the shaft, The coil portion is disposed around the cylindrical portion.

4. The impact tool according to any one of claims 1 to 3, wherein The drive axis is located between the rotation axis and the grip portion in an extension direction of the handle.

5. The impact tool according to claim 4, wherein At least a portion of the grip portion is located on a straight line that intersects the rotation axis and extends in a direction orthogonal to the drive axis.

6. The impact tool according to claim 2 or 3, wherein The tool body and the handle are connected so as to be relatively movable also in an extension direction of the rotation axis, by the at least one elastic member.

7. The impact tool according to any one of claims 1 to 3, wherein The handle is formed of a first member and a second member that are connected to each other in an extension direction of the rotation axis, The at least one elastic member includes a first elastic member that is interposed between the tool body and the first member, and a second elastic member that is interposed between the tool body and the second member.

8. The impact tool according to claim 1, wherein The at least one biasing member is at least one spring that is disposed so that a biasing direction of the at least one spring is substantially coincident with an extension direction of a tangent line of a circle that has the rotation axis as a center.

9. The impact tool according to claim 8, wherein The at least one biasing member includes two springs that are symmetrically disposed with respect to a plane that includes the drive axis and extends in an extension direction of the handle.

10. The impact tool according to claim 1, wherein The at least one force applying member is at least one helical torsion spring configured around the rotational axis. The at least one force applying member is at least one helical torsion spring configured around the rotational axis.

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