Impact tool

Abstract

The invention provides an impact tool. The impact tool is provided with a motor, an impact mechanism and a shell, and the motor is provided with a motor shaft which rotates with a motor rotation axis as the center. An impact mechanism having an impact member adjacent to an air chamber defined inside the cylinder, and converting a rotational motion of the motor shaft into a linear motion of the impact member along a predetermined impact axis by means of an air spring of the air chamber; the housing accommodates the motor and the impact mechanism. The motor rotation axis is configured to be parallel to the impact axis and pass through the inside of the cylinder. Therefore, the impact force on the straight line of the top end tool can be sufficiently obtained while the vibration of the impact tool is restrained.

Description

Technical Field

[0001] The present invention relates to an impact tool. Background Art

[0002] For example, an impact tool is disclosed in the specification of U.S. Patent No. 5,002,134. The impact tool includes: a support shaft that rotates by the driving force of a motor; a rotating body that rotates by the rotation of the support shaft; an impact member that is mounted on the rotating body; and a shovel as a tip tool. In this impact tool, a crank mechanism that rotates by the driving force of the motor is used to convert the rotational motion of the motor into a linear motion of the shovel. Summary of the Invention

[0003] However, in the prior art, since the driving force of the motor is mechanically (by mechanical means) converted into the reciprocating movement of the tip tool, the vibration of the power tool may increase, and in addition, the impact force of the tip tool may not be obtained sufficiently.

[0004] According to a first aspect of the present invention, there is provided an impact tool. The impact tool includes a motor, an impact mechanism, and a housing. The motor has a motor shaft that rotates about a motor rotation axis; the impact mechanism has an impact member adjacent to an air chamber defined inside a cylinder, and uses the air spring of the air chamber to convert the rotational motion of the motor shaft into a linear motion of the impact member along a predetermined impact axis; the housing houses the motor and the impact mechanism. The motor rotation axis is configured to be parallel to the impact axis and pass through the inside of the cylinder.

[0005] In the impact tool according to the above aspect, compared with an impact mechanism that mechanically transmits kinetic energy, by using an impact mechanism with an air spring, the vibration of the impact tool can be suppressed, and a larger kinetic energy can be transmitted to the tip tool. In addition, by bringing the motor rotation axis and the impact axis close to each other and arranging the structure from the motor to the tip tool in a substantially straight line, an impact tool that can easily apply a force in a straight line to the tip tool and is suitable for excavation work can be provided. Brief Description of the Drawings

[0006] Figure 1 It is an explanatory view showing the external structure of the impact tool according to the first embodiment. Figure 2 It is an explanatory view showing the structure of the battery mounting portion. Figure 3 It is a sectional view taken along the line III-III showing Figure 2 of. Figure 4 It is an explanatory view showing the structure of the impact mechanism. Figure 5 is an explanatory diagram showing the V-V position of Figure 1 . [Explanation of reference numerals] 20: Motor; 22: Motor main body; 24: Motor shaft; 26: Fan; 30: Battery mounting part; 32: Guide rail; 34: Terminal; 40: Controller; 50: Impact mechanism; 52: Impact part; 56: Crank part; 60: Housing; 61: Front end part; 62: Impact mechanism housing part; 63: Motor housing part; 64: Rear end part; 70: Main handle; 70L: First connecting part; 70R: Second connecting part; 71: First extension part; 72: Second extension part; 76: Gripping part; 77: Switch trigger; 80: Front handle; 80L, 80R: Connecting parts; 86: Gripping part; 90: Tool holder; 92: Insertion hole; 100: Impact tool; 520: Cylinder; 524: Impact piece; 526: Impact bolt; 561: First bevel gear; 562: Second bevel gear; 562W: Inner peripheral surface; 564: Crank shaft; 564B: Main body part; 564T: Crank plate; 564W: Peripheral part; 565: Bearing; 566: Crank pin; 568: Rod; 569: Piston; 602: Inner housing; 604: Outer housing; 606: Elastomer; BAT: Battery; LT: Light emitting part; SP: Air chamber; TT: Tip tool. Detailed implementation mode

[0007] Hereinafter, representative and non-limiting specific examples of the present invention will be described in detail with reference to the drawings. This detailed description merely shows the details of the preferred examples for implementing the present invention to those skilled in the art, and does not represent a limitation on the scope of the present invention. In addition, the additional features and technical solutions disclosed below can be used alone or together with other features or technical solutions to provide a further improved device, its manufacturing method and use method.

[0008] In addition, the combination of features or processes disclosed in the following detailed description is not essential in implementing the present invention in the broadest sense, and is merely described for particularly illustrating the representative specific examples of the present invention. And the various features of the above and following representative specific examples and the various features described in the independent and dependent claims do not have to be combined as in the specific examples described herein or in the order listed when providing additional and useful implementation modes of the present invention.

[0009] Different from the structures of the features described in the embodiments and / or the claims, all the features described in this specification and / or the claims, as limitations on the disclosure of the original application and the specific matters claimed, are intended to be disclosed separately and independently of each other. Also, regarding all numerical ranges and descriptions of groups or clusters, as limitations on the disclosure content of the original application and the specific matters claimed, it represents the disclosure of the intermediate structures.

[0010] In one or more embodiments, there may also be a main handle, which includes a gripping portion, a first connecting portion, and a second connecting portion. Among them, the gripping portion is configured to be gripped by the user; the first connecting portion connects one end of the gripping portion to the housing; the second connecting portion connects the other end of the gripping portion to the housing. The impact axis may be configured to pass between one end of the gripping portion and the other end of the gripping portion when observing the impact tool along a direction orthogonal to the impact axis. For the impact tool according to this mode, it is easy for the user to operate the main handle to push the impact tool along the impact axis. Therefore, an impact tool suitable for excavation work can be provided.

[0011] In one or more embodiments, the impact mechanism may also have a second bevel gear and a crankshaft. Among them, the second bevel gear meshes with a first bevel gear provided on the motor shaft; the crankshaft is integrally provided with the second bevel gear and rotates together with the second bevel gear. For the impact tool according to this mode, the driving force of the motor can be efficiently transmitted.

[0012] In one or more embodiments, the extending direction of the gripping portion may be a direction parallel to a plane orthogonal to the rotation axis of the second bevel gear and intersecting the impact axis. For the impact tool according to this mode, an impact tool with good weight balance in the state of gripping the main handle can be provided.

[0013] In one or more embodiments, there may be a controller for controlling the motor. The main handle may be connected to the rear end of the housing. The controller may be housed in the housing and be disposed between the motor and the main handle. For the impact tool according to this mode, the controller can be efficiently arranged in the housing.

[0014] In one or more embodiments, a battery mounting portion may also be provided on the housing, and the battery mounting portion can detachably mount a battery for supplying electric power to the motor. The impact axis may be configured to pass through at least a part of the battery mounting portion. In the impact tool according to this mode, by arranging the battery on the impact axis, the enlargement of the housing in the direction intersecting the impact axis can be suppressed or prevented.

[0015] In one or more embodiments, the battery mounting portion may be arranged between the first connecting portion and the second connecting portion in the housing. In the impact tool according to this mode, the battery can be surrounded by the main handle, and the periphery of the battery can be protected by the main handle.

[0016] In one or more embodiments, the housing may include an inner housing and an outer housing, wherein the inner housing is used to house the motor and the impact mechanism; the outer housing is connected to the main handle and is used to house the inner housing. An elastomer may be arranged between the inner housing and the outer housing, and the elastomer abuts against the inner housing and the outer housing. In the impact tool according to this mode, the transmission of vibration from the inner housing, which is a vibration source, to the outer housing during driving of the impact tool can be suppressed or prevented.

[0017] In one or more embodiments, a front handle configured to be held by a user may further be provided. It may be that when the extending direction of the impact axis is defined as the front-rear direction, the main handle is connected to a position on the housing rearward of the rotation axis of the second bevel gear. It may be that the front handle is connected to a position on the housing forward of the rotation axis of the second bevel gear. In the impact tool according to this mode, it is easy for the user to transmit the force of pressing the tip tool against the processing object using the main handle and the front handle to the impact tool. Therefore, an impact tool suitable for excavation work can be provided.

[0018] In one or more embodiments, a light-emitting portion that can irradiate light to the work area may further be provided. In the impact tool according to this mode, by having the light-emitting portion, the visual confirmation of the work area of the impact tool can be improved.

[0019] A. First Embodiment: Hereinafter, with reference to the drawings, the impact tool 100 according to the first embodiment will be described. In the present embodiment, an electric shovel will be described as an example of the impact tool 100. An electric shovel is a portable electric tool used for excavation work such as excavation or crushing of sand, gravel, coal, snow, etc. The electric shovel is configured to be able to use the driving force of a motor to cause a shovel, which is a tip tool TT installed at the tip of a housing 60, to perform a linear reciprocating movement along an impact axis TX (hereinafter, also referred to as a "hammering action"). The use of the shovel is, for example, for civil engineering, farming, or households. The shovel is sometimes also referred to as a "spade", a "scoop", etc. In addition, the impact tool 100 can also be appropriately adapted to work other than excavation work by replacing the tip tool TT.

[0020] In the present specification, for convenience of explanation, the extending direction of the impact axis TX is defined as the "front-rear direction of the impact tool 100". In the front-rear direction, the front end portion 61 side of the housing 60 where the tool holder 90 (refer to Figure 3 ) is arranged is defined as the "front side of the impact tool 100", and the opposite side thereof is defined as the "rear side of the impact tool 100". In addition, the direction parallel to the rotation axis CX of a crankshaft 564 (refer to Figure 3 ) described later is defined as the "up-down direction of the impact tool 100". In the up-down direction, the direction from the crankshaft 564 to the impact axis TX is defined as upward, and the opposite direction thereof is defined as downward. In addition, the direction orthogonal to the front-rear direction and the up-down direction is defined as the left-right direction.

[0021] The impact tool 100 has a housing 60 and a motor 20 (refer to Figure 3 ) and an impact mechanism 50 (refer to Figure 3 ) housed in the housing 60. As Figure 1 shown, the housing 60 has a substantially cylindrical shape and is an elongated hollow box extending along the impact axis TX. The housing 60 includes a front end portion 61 located on the front side of the housing 60, an impact mechanism housing portion 62, a motor housing portion 63, and a rear end portion 64 located on the side opposite to the front end portion 61.

[0022] A main handle 70 is connected to the rear end portion 64 of the housing 60, and a front handle 80 is connected to the impact mechanism housing portion 62. The main handle 70 has a substantially U-shaped configuration. The main handle 70 has a gripping portion 76 configured to be gripped by a user, a first extension portion 71, a second extension portion 72, a first connection portion 70L, and a second connection portion 70R. Both ends of the main handle 70 are fixed to the housing 60 through the first connection portion 70L and the second connection portion 70R. That is, the main handle 70 and the housing 60 are annular in a top view.

[0023] The grip portion 76 is a portion of the main handle 70 configured to be gripped by the user. The grip portion 76 has a substantially cylindrical shape. The extending direction of the grip portion 76 can be defined, for example, by the axial direction of the central axis HX of the grip portion 76. As Figure 3 and Figure 5 shown, the extending direction of the grip portion 76 is, for example, a direction parallel to the plane OS in a plane orthogonal to the rotation axis CX of the second bevel gear 562 and orthogonal to the impact axis TX. In the present embodiment, the extending direction of the grip portion 76 coincides with the left-right direction. By configuring in this way, the grip position of the main handle 70 and the center of gravity positions of the second bevel gear 562 and the crankshaft 564 can be arranged in a positional relationship with good weight balance in the left-right direction of the impact tool 100. In addition, the extending direction of the grip portion 76, for example, on the premise of being parallel to the plane OS, may not be orthogonal to the impact axis TX, or may be a direction intersecting the impact axis TX at a specified angle. The intersection of the central axis HX of the grip portion 76 and the outer surface on the left side in the grip portion 76 is also referred to as "one end 76L of the grip portion 76", and the intersection of the central axis HX and the outer surface on the right side in the grip portion 76 is referred to as "the other end 76R of the grip portion 76". The first extension portion 71 is a portion of the main handle 70 that connects the first connection portion 70L and one end 76L of the grip portion 76. The second extension portion 72 is a portion of the main handle 70 that connects the second connection portion 70R and the other end 76R of the grip portion 76.

[0024] As Figure 3 shown, the grip portion 76 of the main handle 70 is arranged at a position rearward of the rotation axis CX of the second bevel gear 562 and rearward of the housing 60. In addition, when observing the impact tool 100 along the direction orthogonal to the impact axis TX, that is, in the top view along the Figure 5 shown up-down direction, the impact axis TX passes through the range between one end 76L and the other end 76R of the grip portion 76. In the present embodiment, it is configured such that the impact axis TX passes through the grip portion 76. In addition, in Figure 3In the example, the impact axis TX intersects with the central axis HX of the gripping portion 76. By arranging the extending direction of the main handle 70 along the impact axis TX, it is easy for the user to perform the operation of pressing the rear end of the main handle 70 to push out the tip tool TT along the impact axis TX. In addition, by arranging the gripping portion 76 on the impact axis TX, it is even easier for the user to press the rear end of the main handle 70 to push out the tip tool TT along the impact axis TX. Therefore, an impact tool 100 suitable for excavation work can be provided. For example, the impact axis TX may not be orthogonal to the extending direction of the gripping portion 76, or may intersect the extending direction of the gripping portion 76 at a specified angle within the range between one end 76L and the other end 76R of the gripping portion 76. The gripping portion 76 may be offset upward or downward relative to the impact axis TX, or may be offset upward or downward relative to the plane OS.

[0025] In addition, the plane OS in the plane orthogonal to the rotation axis CX of the second bevel gear 562 is configured to pass through the gripping portion 76, the first connecting portion 70L, and the second connecting portion 70R. In other words, the main handle 70 is configured to extend rearward from the housing 60 along the plane OS. In Figure 1 the example, the first extension portion 71 extends rearward from the first connecting portion 70L, and the second extension portion 72 extends rearward from the second connecting portion 70R. According to the impact tool 100 configured in this way, an impact tool 100 suitable for excavation work can be provided, in which it is easy for the user to apply force along the plane direction of the plane OS using the main handle 70. In addition, in the present embodiment, the plane OS is configured to pass through the central axis HX of the gripping portion 76 in the gripping portion 76.

[0026] As Figure 1 shown, the front handle 80 has a substantially U-shaped configuration. The front handle 80 has a gripping portion 86 configured to be gripped by the user and connecting portions 80L, 80R. The gripping portion 86 has a substantially cylindrical shape extending in the left-right direction and is arranged on the upper side of the housing 60. Both ends of the front handle 80 are connected to the housing 60 through the connecting portions 80L, 80R. In the present embodiment, the connecting portions 80L, 80R support the front handle 80 in such a manner that the position of the front handle 80 relative to the housing 60 around the support axis FX can be adjusted. In addition, the front handle 80 is not limited to the position-adjustable manner and may also be fixed to the housing 60. For example, the front handle 80 may be installed in a state where it is reversed in the up-down direction from Figure 1 the state. In this case, the gripping portion 86 is arranged on the lower side of the housing 60. In addition, for example, the front handle 80 may be configured to be detachable from the housing 60. In this case, the front handle 80 may be configured to be arbitrarily switched to any position on the upper side or the lower side of the housing 60 according to the user's expectation.

[0027] The connecting portions 80L and 80R are connected to a position in the housing 60 that is slightly forward of the center in the front-rear direction of the housing 60. Specifically, as Figure 4 shown, the front handle 80 is connected to a position in the housing 60 that is forward of the rotation axis CX of the second bevel gear 562. Accordingly, it is easy for the user to transmit the force of pressing the tip tool TT against the work object using the front handle 80 to the impact tool 100. Therefore, an impact tool 100 suitable for excavation work can be provided.

[0028] In the present embodiment, the support axis FX of the front handle 80 is configured to be orthogonal to the impact axis TX. When the user pushes the housing 60 forward using the front handle 80, the force is transmitted to the housing 60 via the support axis FX by operating the front handle 80. Therefore, with the impact tool 100 according to the present embodiment, it is easy for the user to push the housing 60 forward along the impact axis TX. Therefore, an impact tool 100 suitable for excavation work can be provided.

[0029] As Figure 1 shown, a switch trigger 77 is provided at the gripping portion 76 of the main handle 70. The switch trigger 77 is a so-called momentary switch. For example, when the user presses the switch trigger 77 while gripping the gripping portion 76, the drive motor 20 is driven and the impact tool 100 switches to the on state.

[0030] The switch trigger 77 is provided at a position of the gripping portion 76 facing the rear end portion 64 of the housing 60. When using the impact tool 100, the user uses the impact tool 100 while gripping the gripping portion 76 of the main handle 70 with one hand and the gripping portion 86 of the front handle 80 with the other hand, for example. The user presses the tip tool TT against a work object such as the ground and pushes the impact tool 100 forward using the main handle 70, thereby performing excavation work on the work object. The user can switch the on / off of the switch trigger 77 during the operation of the main handle 70, thereby being able to perform a hammering action at any point in time during the excavation work. In addition, the user can appropriately perform the action of lifting the impact tool 100 by using the front handle 80. Therefore, an impact tool 100 suitable for excavation work can be provided.

[0031] A light emitting portion LT is provided on the housing 60. The light emitting portion LT is, for example, an LED illumination using the battery BAT as a power source. The light emitting portion LT is configured to be able to irradiate light to the tip tool TT and the work area including the work object or its surroundings. By having the light emitting portion LT, the visual confirmation of the work area of the impact tool 100 can be improved. In the present embodiment, the light emitting portion LT is arranged at a position surrounded by the front handle 80. Therefore, the light emitting portion LT can be protected from impacts and the like by the front handle 80.

[0032] At the rear end portion 64 of the housing 60, a battery BAT for supplying electric power to the motor 20 is arranged. In the present invention, the battery BAT uses a rechargeable battery with a well-known structure.

[0033] In Figure 2 is shown the impact tool 100 with the battery BAT removed. As Figure 2 shown, at the rear end portion 64 of the housing 60, a battery mounting portion 30 for mounting the battery BAT is provided. In addition, for easy understanding of the technology, in Figure 2 the position of the battery BAT in the state of being mounted on the battery mounting portion 30 is illustrated by a dashed line for easy understanding.

[0034] The battery mounting portion 30 has a guide rail 32 and terminals 34. The battery mounting portion 30 may also have a locking mechanism for restricting the detachment of the battery BAT. The guide rail 32 is formed in a convex shape along the vertical direction. The guide rail 32 engages with a concave track engaging portion (not shown) provided on the battery BAT. The guide rail 32 defines Figure 1 the detachment and attachment direction DB when the battery BAT is detached and attached as shown. The battery BAT mounted on the battery mounting portion 30 is electrically connected via the terminals 34, so that electric power can be supplied to the motor 20 and the like.

[0035] When the central axis of the gripping portion 76 is defined as the "central axis HX", the detachment and attachment direction DB of the battery BAT is set to a direction intersecting the central axis HX on the premise that the battery BAT does not interfere with the main handle 70. In Figure 2 the example of, the detachment and attachment direction DB is orthogonal to the impact axis TX. That is, the detachment and attachment direction DB is a direction that coincides with the vertical direction and is orthogonal to the central axis HX. The user can detach the battery BAT from the battery mounting portion 30 by pulling the battery BAT upward along the detachment and attachment direction DB. In addition, the user can mount the battery BAT on the battery mounting portion 30 by pushing the battery BAT downward along the detachment and attachment direction DB. Since the detachment and attachment can be performed in a direction intersecting the central axis HX of the gripping portion 76, even when the user holds the main handle 70 or the front handle 80 with one hand, the battery BAT can be easily detached and attached with the other hand. It is also possible that the detachment and attachment direction DB of the battery BAT is defined as a direction that obliquely intersects the impact axis TX on the premise that the battery BAT does not interfere with the main handle 70. In addition, the battery BAT can be detached by pulling it downward along the detachment and attachment direction DB, and can be mounted by pushing it upward along the detachment and attachment direction DB.

[0036] As Figure 2 shown, the battery mounting portion 30 is arranged at a position between the two ends of the main handle 70 at the rear end portion 64 of the housing 60. In Figure 2In the example, the battery mounting portion 30 is disposed between the first connection portion 70L and the second connection portion 70R. By configuring the battery BAT to be surrounded by the main handle 70, the periphery of the battery BAT can be protected by the main handle 70. For example, the battery BAT can be protected from the impact when the impact tool 100 falls, etc.

[0037] As Figure 3 shown, the battery mounting portion 30 is configured such that the impact axis TX passes through the battery mounting portion 30. In other words, the battery mounting portion 30 is disposed on the back surface of the housing 60. By disposing the battery BAT on the impact axis TX, an increase in the size of the housing 60 in the radial direction intersecting the impact axis TX can be suppressed or prevented.

[0038] Use Figures 3 to 5 to describe the internal structure of the housing 60. As Figure 3 shown, in the present embodiment, the housing 60 includes an inner housing 602 and an outer housing 604. The outer housing 604 is a part that houses the inner housing 602 and forms the outer contour of the housing 60. The main handle 70 is connected to the outer housing 604. The motor 20, the controller 40, the impact mechanism 50, and the tool holder 90 are housed in the inner housing 602. The front handle 80 is connected to the inner housing 602. The tool holder 90 detachably holds the tip tool TT in the insertion hole 92 provided at the front end portion 61 of the housing 60.

[0039] The motor 20 is driven by the electric power supplied from the battery BAT mounted on the battery mounting portion 30. The motor 20 is a brushless DC motor that is driven under the control of the controller 40. As Figure 3 shown, the motor 20 is housed in the motor housing portion 63 behind the impact mechanism housing portion 62 in the housing 60, and is configured such that the impact axis TX passes through the motor 20. By disposing the motor rotation axis MX of the motor 20 close to the impact axis TX, the radial dimension of the impact tool 100 can be reduced.

[0040] As Figure 4 shown, the motor 20 has a motor body 22, a motor shaft 24, and a fan 26. The motor body 22 includes a stator and a rotor. The motor body 22 is disposed in the inner housing 602 in the motor housing portion 63. The motor shaft 24 rotates together with the rotor about the motor rotation axis MX. The front end of the motor shaft 24 projects into the impact mechanism housing portion 62. A first bevel gear 561 is provided at the front end of the motor shaft 24. The fan 26 rotates together with the motor shaft 24 to generate an air flow for cooling the motor body 22.

[0041] As Figure 3As shown, the controller 40 is composed of a computer having a CPU as a processor and a memory such as RAM or ROM. The controller 40 is configured to control various operations of the impact tool 100 such as the drive control of the motor 20. The controller 40 is disposed between the motor 20 and the main handle 70 in the housing 60. The controller 40 has a substantially flat plate shape and is disposed in the housing 60 in such a manner that its plane direction intersects the motor rotation axis MX. By accommodating the controller 40 at the rear side of the housing 60 where a space is easily formed, the controller 40 can be efficiently disposed in the housing 60. Further, in the present embodiment, the controller 40 is disposed at the rear end portion 64 of the housing 60 that is more rearward than the motor accommodating portion 63 and is disposed between the motor 20 and the battery mounting portion 30. Further, it is configured such that the impact axis TX passes through the controller 40. By configuring in this way, the size in the radial direction of the housing 60 can be miniaturized.

[0042] As Figure 4 shown, the impact mechanism 50 has an impact portion 52 and a crank portion 56. The crank portion 56 converts the rotational motion of the motor shaft 24 into a linear motion of the impact member 524 along the impact axis TX and transmits the kinetic energy of the rotational motion of the motor shaft 24 to the impact member 524. The impact portion 52 transmits the kinetic energy of the impact member 524 transmitted from the crank portion 56 to the tip tool TT.

[0043] The crank portion 56 has a first bevel gear 561, a second bevel gear 562, a crankshaft 564, a rod member 568, and a piston 569. The first bevel gear 561 is provided at the front end of the motor shaft 24. The first bevel gear 561 meshes with the second bevel gear 562 in the impact mechanism accommodating portion 62. The crankshaft 564 includes a main body portion 564B, a crank plate 564T, and a peripheral portion 564W. The peripheral portion 564W is a portion of the crankshaft 564 that is continuous with the crank plate 564T around the rotation axis CX.

[0044] The second bevel gear 562 is provided on the outer periphery of the crankshaft 564. The second bevel gear 562 is integrally formed with the crankshaft 564. In the present embodiment, the inner peripheral surface 562W of the second bevel gear 562, which is separate from the crankshaft 564, is engaged with the peripheral edge portion 564W of the crankshaft 564 by press-fitting or the like, whereby a single component having the functions of the crankshaft 564 and the second bevel gear 562 is formed. Through the crankshaft 564 and the second bevel gear 562, the driving force of the motor 20 can be efficiently transmitted. The crankshaft 564 is rotatably supported by a plurality of bearings 565 in the inner housing 602 and rotates about the rotation axis CX together with the second bevel gear 562. Therefore, the rotation axis CX of the crankshaft 564 coincides with the rotation axis of the second bevel gear 562. The rotation axis CX is orthogonal to the motor rotation axis MX and the impact axis TX. A space 564S for arranging the bearings 565 is defined below the crank plate 564T and between the peripheral edge portion 564W and the main body portion 564B. By arranging the bearings 565 in this space 564S, the crankshaft 564, the bearings 565, and the second bevel gear 562 can be arranged side by side in the radial direction of the crankshaft 564. Therefore, the size of the rotation axis CX in the axial direction of the arrangement region of the crankshaft 564, the bearings 565, and the second bevel gear 562 can be miniaturized. In addition, the second bevel gear 562 and the crankshaft 564 may also be integrally formed by molding or the like.

[0045] The rotation of the motor shaft 24 is transmitted to the second bevel gear 562 and the crankshaft 564 through the first bevel gear 561. The crankshaft 564 and the second bevel gear 562 receive the rotation of the first bevel gear 561 and rotate about the rotation axis CX orthogonal to the motor rotation axis MX.

[0046] The crankshaft 564 transmits the kinetic energy transmitted from the motor 20 to the impact portion 52. A crank pin 566 is provided on the crank plate 564T of the crankshaft 564. A rod member 568 is mounted on the crank pin 566, and the rod member 568 connects the crank pin 566 and the piston 569.

[0047] The crank pin 566 is offset from the rotation axis CX. When the crankshaft 564 rotates, the crank pin 566 rotates about the rotation axis CX. As the crankshaft 564 rotates, the rod member 568 swings in the front-rear direction perpendicular to the rotation axis CX. The rotational motion of the crankshaft 564 is transmitted to the piston 569 via the rod member 568.

[0048] The piston 569 is a substantially cylindrical member. The piston 569 is arranged inside the cylinder 520 formed in the inner housing 602 so as to be slidable along the impact axis TX. The piston 569 reciprocates in the front-rear direction via the rod member 568 that swings due to the rotation of the crank pin 566.

[0049] The impact section 52 has an impact member 524 and a striker 526. The impact member 524 applies an impact force to the tip tool TT. The impact member 524 is disposed inside the cylinder 520 so as to be slidable along the impact axis TX. Inside the cylinder 520, an air chamber SP that functions as an air spring is defined between the piston 569 and the impact member 524. The striker 526 is an intermediate member that transfers the kinetic energy of the impact member 524 to the tip tool TT. The striker 526 is disposed on the front side of the impact member 524 so as to be movable along the impact axis TX.

[0050] When the piston 569 reciprocates in the front-rear direction as the rod member 568 swings, the internal pressure of the air chamber SP changes, and under the action of the air spring, the impact member 524 slides in the front-rear direction inside the cylinder 520. More specifically, when the piston 569 moves forward, the distance between the piston 569 and the impact member 524 shortens. As a result, the air in the air chamber SP is compressed, and the internal pressure inside the cylinder 520 rises. The impact member 524 is pushed forward at high speed by the action of the air spring, thereby impacting the striker 526.

[0051] The impacted striker 526 transfers the kinetic energy of the impact member 524 to the tip tool TT. The tip tool TT to which the kinetic energy has been transferred is linearly driven along the impact axis TX. Compared with the case of mechanically transferring kinetic energy to the tip tool TT, the impact tool 100 of the present embodiment can suppress the vibration of the impact tool 100 and transfer a larger amount of kinetic energy to the tip tool TT by utilizing the action of the air spring.

[0052] When the piston 569 moves backward, the distance between the piston 569 and the impact member 524 increases, and the air in the air chamber SP expands. As a result, the internal pressure of the cylinder 520 decreases, and the impact member 524 is pulled backward. The impacted tip tool TT comes into contact with the workpiece, and together with the striker 526, moves backward by the reaction force from the workpiece. Thereafter, the hammering action performed by the impact mechanism 50 is repeated in the same manner.

[0053] As Figure 4 shown, in the impact tool 100 of the present embodiment, the motor rotation axis MX and the impact axis TX are configured to be close to each other. From the viewpoint of bringing the motor rotation axis MX and the impact axis TX close to each other, the motor rotation axis MX is configured to pass through the inside of the cylinder 520. In Figure 4In the example, the motor rotation axis MX of the motor shaft 24 is configured at a position slightly lower than the impact axis TX and is configured to be parallel to the impact axis TX. By bringing the motor rotation axis MX and the impact axis TX closer to each other, the structure from the motor 20, which is the driving source of kinetic energy, to the tip tool TT is arranged on a substantially straight line, and the center of gravity of the entire impact tool 100 can be brought closer to the impact axis TX. Therefore, the operability of the impact tool 100 can be improved. In addition, it can also be configured such that the motor rotation axis MX and the impact axis TX coincide with each other. Further, while bringing the motor rotation axis MX and the impact axis TX closer to each other, the motor rotation axis MX can be arranged above, to the left, or to the right of the impact axis TX. Even in such a configuration, by bringing the center of gravity of the entire impact tool 100 closer to the impact axis TX, the operability of the impact tool 100 can be improved.

[0054] As Figure 5 shown, in the present embodiment, an elastomer 606 is provided between the inner housing 602 and the outer housing 604. The elastomer 606 is, for example, a resin material such as polyurethane or silicone. The elastomer 606 has, for example, a substantially cubic shape. The elastomer 606 is held in a state of abutting against the inner housing 602 and the outer housing 604. In Figure 5 the example, the housing 60 has four elastomers 606. Specifically, in the front-rear direction of the housing 60, two portions are arranged front and rear across the rotation axis CX, and in the two front and rear portions, two portions are arranged left and right across the impact axis TX respectively.

[0055] By providing the elastomer 606 between the inner housing 602 and the outer housing 604, the transmission of vibration from the inner housing 602, which is the vibration source, to the outer housing 604 during the hammering operation can be suppressed or prevented. In addition, the generation of wobbling between the inner housing 602 and the outer housing 604 due to dimensional errors in the manufacture of the inner housing 602 or the outer housing 604 can be suppressed or prevented. Further, the number of the elastomers 606 can be arbitrarily set. The elastomer 606 can be a single number or any number of two or more. The elastomer 606 is not limited to a resin material, and a metal material such as a metal spring can also be used. The shape of the elastomer 606 is not limited to a cube, and can be any shape such as a cuboid, a sphere, or a columnar body. The elastomer 606 can also be an annular member such as an O-ring continuously arranged around the inner housing 602.

[0056] B. Another Embodiment: (B1)In the above-described embodiment, an example in which a spatula is used as the tip tool TT has been described. In contrast, a tool other than a spatula may be used as the tip tool TT. For example, the tip tool TT may also be a so-called spatula, a scraper, or the like, which is a tool for performing a peeling operation on a processing object. Similar to the excavation operation, the peeling operation can perform an action of pressing the impact tool 100 against the processing object. Therefore, the impact tool 100 shown in the above-described embodiment is also suitable for the peeling operation. In addition, the tip tool TT may also be a needle gun scaler, a needle scaler, or a needle gun, etc., which reciprocates back and forth through a plurality of needle-shaped components and presses against the processing object to peel off rust and coatings on the surface of the processing object. In addition, the spatula may be a spatula standardized according to Japanese Industrial Standards (JIS), or may be a spatula other than this. The spatula may have a part to be stepped on, or may not have a part to be stepped on.

[0057] (B2)And, in view of the gist of the present invention and the above-described embodiments, the following modes are constructed. The following modes can be used in combination with the impact tool 100 shown in each embodiment and the inventions described in the above-described modified examples or each technical solution. [Mode 1] The impact axis is configured to pass through the motor. [Mode 2] The front handle is supported in a position-adjustable manner with respect to the housing, and the support axis of the front handle is orthogonal to the impact axis. [Mode 3] The impact axis is configured to pass through the controller. [Mode 4] The controller is disposed at a position behind the motor in the housing. [Mode 5] The controller is disposed between the motor and the battery mounting portion.

Claims

1. An impact tool, characterized in that, it has a motor, an impact mechanism and a housing, wherein, the motor has a motor shaft that rotates about a motor rotation axis; the impact mechanism has an impact member adjacent to an air chamber defined inside a cylinder, and converts the rotational movement of the motor shaft into a linear movement of the impact member along a predetermined impact axis by means of an air spring of the air chamber; the housing houses the motor and the impact mechanism, the motor rotation axis is configured to be parallel to the impact axis and pass through the inside of the cylinder.

2. The impact tool according to claim 1, characterized in that, it further has a main handle, which includes a gripping portion, a first connecting portion and a second connecting portion, wherein, the gripping portion is configured to be gripped by a user; the first connecting portion connects one end of the gripping portion to the housing; the second connecting portion connects the other end of the gripping portion to the housing, the impact axis is configured to pass between one end of the gripping portion and the other end of the gripping portion when observing the impact tool in a direction orthogonal to the impact axis.

3. The impact tool according to claim 2, characterized in that, the impact mechanism further has a second bevel gear and a crankshaft, wherein, the second bevel gear meshes with a first bevel gear provided on the motor shaft; the crankshaft is integrally provided with the second bevel gear and rotates together with the second bevel gear.

4. The impact tool according to claim 3, characterized in that, the extending direction of the gripping portion is a direction parallel to a plane orthogonal to the rotation axis of the second bevel gear and intersecting the impact axis.

5. The impact tool according to any one of claims 2 to 4, characterized in that, it has a controller for controlling the motor, the main handle is connected to the rear end portion of the housing, the controller is housed in the housing and is arranged between the motor and the gripping portion.

6. The impact tool according to any one of claims 1 to 5, characterized in that, the housing further has a battery mounting portion, which can be disassembled and assembled with a battery for supplying electric power to the motor, the impact axis is configured to pass through the battery mounting portion.

7. The impact tool according to claim 6, which directly or indirectly depends on claim 2, characterized in that, the battery mounting portion is arranged between the first connecting portion and the second connecting portion in the housing.

8. The impact tool according to claim 2, or according to any one of claims 3 to 7 which directly or indirectly depend on claim 2, characterized in that, the housing includes an inner housing and an outer housing, wherein, the inner housing is for housing the motor and the impact mechanism; the outer housing is connected to the main handle and houses the inner housing, an elastic body is arranged between the inner housing and the outer housing, and the elastic body abuts against the inner housing and the outer housing.

9. The impact tool according to claim 3, or according to any one of claims 4 to 8 which directly or indirectly depend on claim 3, characterized in that, It also has a front handle configured to be held by the user. When the extending direction of the impact axis is defined as the front-rear direction, the main handle is connected to the housing at a position rearward of the rotation axis of the second bevel gear, and the front handle is connected to the housing at a position forward of the rotation axis of the second bevel gear.

10. The impact tool according to any one of claims 1 to 9, characterized in that it also has a light-emitting part that can irradiate light to the work area.

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