Work equipment

Abstract

Suppresses a decline in work efficiency. [Solution] In the hammer 1, the housing 10 has a resin housing body 12 and a metal support cylinder 20. An exposed hole 18A is formed in the support base portion 18 of the housing body 12, and the inner metal exposed portion 20A of the metal support cylinder 20 is positioned inside the exposed hole 18A, so that the metal support cylinder 20 is exposed from both sides FB in the front and back direction of the housing 10. Therefore, by attaching the sub-handle 70 to the outer circumference of the metal support cylinder 20, the wear resistance of the housing 10 can be ensured, and by supporting the inner case 41 with the inner circumference of the metal support cylinder 20, the wear resistance of the housing 10 can be ensured. Thus, the wear resistance of the housing 10 can be ensured, and the decrease in the workability of the hammer 1 can be suppressed.

Description

Technical Field

[0001] The present invention relates to a working machine.

Background Art

[0002] In the hammer (working machine) described in Patent Document 1 below, a sub-handle is detachably attached to the outer peripheral surface of a housing. In a breaking process or the like using the hammer, an operator holds the handle with one hand and the sub-handle with the other hand to apply a striking force from a tip tool to a work object. Thereby, the operator can perform a breaking process while supporting the hammer with both hands.

[0003] Also, in the hammer, a mechanism for applying a striking force to a tip tool is housed inside the housing. Here, in some hammers, the mechanism is configured to be relatively movable in the front-rear direction with respect to the housing in order to reduce the transmission of vibration generated during striking to the handle. In this hammer, the mechanism is supported movably by the inner peripheral surface of the housing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in the form of a hammer having a sub-handle, the direction of the sub-handle can be changed by rotating the sub-handle with respect to the housing. However, when changing the direction of the sub-handle, the attachment portion of the sub-handle slides on the outer peripheral portion of the housing, so the outer peripheral portion of the housing may wear. In this case, the support state of the sub-handle cannot be maintained well, and the workability of the hammer may decrease.

[0006] Furthermore, in hammer configurations where the housing supports the mechanism in a manner that allows for relative movement, the mechanism slides against the inner circumference of the housing during relative movement, potentially causing wear on the inner circumference of the housing. In this case, it may become impossible to maintain good support for the mechanism, potentially reducing the hammer's workability. For these reasons, it is desirable for hammers to have a structure that ensures wear resistance of the housing and suppresses a decrease in the hammer's workability, regardless of the various configurations in which the housing acts as a support member.

[0007] The present invention aims to provide a work machine that can suppress a decrease in work efficiency, taking the above facts into consideration. [Means for solving the problem]

[0008] One or more embodiments of the present invention include a drive mechanism comprising a drive source and operating by the driving force of the drive source, and a housing covering at least a part of the drive mechanism and having a resin housing made of resin and a metal housing made of metal, wherein the resin housing has an exposed hole formed therethrough in the front-back direction of the resin housing, and a part of the metal housing is arranged in the exposed hole and exposed from both sides of the housing in the front-back direction.

[0009] One or more embodiments of the present invention are a work machine in which the drive mechanism comprises a cylinder extending in a predetermined direction, a piston provided inside the cylinder and reciprocating along the predetermined direction, and a cylinder case housing the cylinder, the resin housing having a cylindrical housing portion extending in the predetermined direction, and the metal housing being formed in a cylindrical shape extending in the predetermined direction and provided in the housing portion, with the cylinder case housed inside the housing portion and the metal housing.

[0010] One or more embodiments of the present invention are work machines in which one of the front and back surfaces of the metal housing is continuously exposed over the entire circumference of the metal housing, and the other of the front and back surfaces of the metal housing is intermittently exposed in the circumference of the metal housing.

[0011] One or more embodiments of the present invention are a work machine in which the cylinder, the cylinder case, the housing cylindrical portion, and the metal housing are formed in a cylindrical shape with the predetermined direction as the axial direction and are arranged coaxially.

[0012] One or more embodiments of the present invention are a work machine in which the housing cylindrical portion has a base portion, the base portion has the exposed hole formed therein, the metal housing is arranged adjacent to the radially outer side of the base portion, the outer circumferential surface of the metal housing is continuously exposed over the entire circumference of the metal housing, the metal housing is provided with an inner metal exposed portion, the inner metal exposed portion is arranged inside the exposed hole and is exposed radially inward of the base portion.

[0013] One or more embodiments of the present invention are work machines in which a handle is provided on the resin housing, a sub-handle is detachably attached to the metal housing, and the surface of the metal housing is the mounting surface for the sub-handle.

[0014] One or more embodiments of the present invention are work machines in which the cylinder case is configured to be movable relative to the housing in the predetermined direction.

[0015] One or more embodiments of the present invention are work machines in which a contact portion is provided on the outer circumferential surface of the cylinder case, protruding toward the inner metal exposed portion, and the cylinder is movably supported in the metal housing by the contact portion abutting toward the inner metal exposed portion.

[0016] One or more embodiments of the present invention are a working machine in which the inner metal exposed portion and the base portion are alternately arranged in the circumferential direction of the base portion, and a plurality of the contact portions are provided on the cylinder.

[0017] One or more embodiments of the present invention are a working machine in which the inner metal exposed portion protrudes radially inward of the metal housing more than the base portion.

[0018] One or more embodiments of the present invention are a working machine in which the metal housing is integrally formed with the base portion, and the total length of the plurality of inner metal exposed portions in the circumferential direction of the metal housing is less than 1 / 2 of the circumferential length of the base portion.

Advantages of the Invention

[0019] According to one or more embodiments of the present invention, it is possible to improve workability that can suppress a decrease in workability.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view seen from the front left obliquely showing the hammer according to this embodiment. [Figure 2] It is a cross-sectional view seen from the left showing the inside of the hammer shown in FIG. 1. [Figure 3] It is a cross-sectional view seen from the rear showing the inside of the rear part of the hammer shown in FIG. 2 (a cross-sectional view taken along line 3-3 of FIG. 2). [Figure 4] It is a cross-sectional view seen from the front showing the inside of the rear part of the hammer shown in FIG. 2 (a cross-sectional view taken along line 4-4 of FIG. 2). [Figure 5] It is a cross-sectional view seen from the front showing the periphery of the metal support cylinder of the hammer shown in FIG. 2 (a cross-sectional view taken along line 5-5 of FIG. 2). [Figure 6] It is a perspective view showing the front housing part and the metal support cylinder of the hammer shown in FIG. 1 disassembled.

Modes for Carrying Out the Invention

[0021] Hereinafter, the hammer 1 as a working machine according to the present embodiment will be described with reference to the drawings. The hammer 1 is a power tool for performing a breaking process or the like on a workpiece. The arrows UP, FR, and LH appropriately shown in the drawings indicate the upper side, the front side, and the left side of the hammer 1. In the following description, when the up-down, front-back, and left-right directions are used for explanation, unless otherwise specified, they indicate the up-down direction, the front-back direction, and the left-right direction of the hammer 1. And the front-back direction corresponds to the predetermined direction of the present invention. Further, in the drawings, for the sake of convenience, hatching is appropriately omitted.

[0022] As shown in FIGS. 1 and 2, the hammer 1 includes a housing 10 and a striking force applying mechanism 40 as a driving mechanism for applying a striking force to the tip tool T.

[0023] (Regarding the housing 10) The housing 10 is formed in a hollow shape and constitutes the outer shell of the hammer 1. The housing 10 includes a housing body 12 as a resin housing and a metal support cylinder 20 as a metal housing. Hereinafter, the housing body 12 will be described, and the metal support cylinder 20 will be described later.

[0024] The housing body 12 is made of resin and is formed in a hollow shape to constitute the outer shell of the hammer 1. The housing body 12 has a rear housing portion 14 constituting the rear portion of the housing body 12 and a front housing portion 16 as a housing cylinder portion constituting the front portion of the housing body 12.

[0025] The rear housing portion 14 is formed in a substantially hollow, flattened box shape with the left-right direction as the thickness direction. The rear housing portion 14 is composed of two housing members, one on the left and one on the right, and the rear housing portion 14 is formed by assembling these housing members together. A handle 14A extending in the vertical direction is provided at the rear end of the rear housing portion 14. Both vertical ends of the handle 14A are bent forward and connected to the rear housing portion 14. Battery mounting portions 14B are provided on both sides below the handle 14A of the rear housing portion 14 (only the left battery mounting portion 14B is shown in Figure 1), and a battery 30 is mounted in the battery mounting portion 14B from the rear.

[0026] A trigger 32 is provided on the upper part of the handle 14A, and the trigger 32 protrudes forward from the handle 14A so that it can be pulled backward. A switch (not shown) is provided inside the handle 14A, and the switch is turned on when the operator pulls the trigger 32. The switch is electrically connected to a controller (not shown) provided inside the rear housing 14, and outputs an output signal to the controller according to the operating state of the trigger 32.

[0027] As shown in Figure 6, the front housing portion 16 is formed in a substantially cylindrical shape with the front-rear direction as its axial direction. The rear end of the front housing portion 16 is a support base portion 18. A flange portion 16A is formed on the outer circumference of the front housing portion 16 in front of the support base portion 18. The flange portion 16A extends along the circumferential direction of the front housing portion 16 and is formed around the entire circumference of the front housing portion 16. The rear surface of the flange portion 16A is formed along a plane perpendicular to the front-rear direction. At the rear end of the front housing portion 16, a protruding portion 16B is formed on the rear side of the support base portion 18, extending radially outward. The protruding portion 16B is formed in a substantially bottomed rectangular cylindrical shape that is open to the rear, and the rear end of the protruding portion 16B is assembled to the front end of the rear housing portion 14 so as not to move relative to it.

[0028] As shown in Figure 5, the support base portion 18 has multiple (six in this embodiment) exposed holes 18A formed through it. The exposed holes 18A penetrate the support base portion 18 (housing 10) in the front-to-back direction FB (in other words, in the thickness direction of the housing 10, or the radial direction of the front housing portion 16). The exposed holes 18A are formed in a substantially rectangular shape with the front-to-back direction as the longitudinal direction when viewed from the radial direction of the support base portion 18, and are arranged in a line with predetermined intervals around the circumferential direction of the support base portion 18. Specifically, one exposed hole 18A is formed at the right end of the support base portion 18, and multiple exposed holes 18A are arranged at 60-degree intervals around the circumferential direction of the support base portion 18. The exposed holes 18A extend over the entire front-to-back direction of the support base portion 18. The length L1 (see Figure 5) of the exposed holes 18A in the circumferential direction of the support base portion 18 is set to be smaller than the circumferential length L2 (see Figure 5) of adjacent support base portions 18 in the circumferential direction. In other words, the sum of the lengths L1 of the multiple exposed holes 18A in the circumferential direction of the support base portion 18 is set to be less than half of the total circumferential length of the support base portion 18.

[0029] (Regarding the impact force application mechanism 40) As shown in Figure 2, the impact force application mechanism 40 is composed of an inner case 41, a motor 50 as a drive source, and a power transmission mechanism 52 as a transmission mechanism.

[0030] (Regarding Inner Case 41) The inner case 41 is housed within the housing body 12 and is supported so as to be movable in the front-rear direction by the metal support cylinder 20 of the housing 10, which will be described later. In other words, the inner case 41 is configured to be relatively movable in the front-rear direction relative to the housing 10. The inner case 41 is composed of a motor case 42 which constitutes the rear part of the inner case 41 and a cylinder case 43 which constitutes the front part of the inner case 41.

[0031] The motor case 42 is formed in a roughly hollow box shape that opens to the front and is housed within the rear housing portion 14. As shown in Figures 2 to 4, a first vibration damping spring 45 is provided on the rear side of the upper end of the motor case 42. The first vibration damping spring 45 is a compression coil spring that extends in the front-rear direction. The front end of the first vibration damping spring 45 is supported in the middle of the left-right direction at the upper end of the motor case 42, and the rear end of the first vibration damping spring 45 is supported on the rear wall of the rear housing portion 14, so that the first vibration damping spring 45 biases the inner case 41 forward. The front end of the motor case 42 abuts against the rear housing portion 14, restricting the forward movement of the inner case 41, thereby holding the inner case 41 in its initial position (the position shown in Figure 2).

[0032] Furthermore, a spring holder 46 is provided inside the rear housing portion 14 at the rear side of the lower end of the motor case 42. The spring holder 46 is formed in a substantially elongated shape extending in the left-right direction and is fixed to the rear housing portion 14. Between the motor case 42 and the spring holder 46, a pair of left and right second vibration-damping springs 47 (see Figure 4) are provided. The second vibration-damping springs 47 are compression coil springs extending in the front-rear direction. The front end of the second vibration-damping spring 47 is supported by the left-right outer end of the lower end of the motor case 42, and the rear end of the second vibration-damping spring 47 is supported by the left-right outer end of the spring holder 46, so that the second vibration-damping springs 47 bias the inner case 41 forward.

[0033] Furthermore, a third vibration-damping spring 48 is provided on the rear side of the motor case 42. The third vibration-damping spring 48 is a leaf spring with its thickness in the front-to-back direction and is formed in a roughly H-shape when viewed from the front-to-back direction. The upper end of the third vibration-damping spring 48 is fixed to the upper end of the motor case 42, and the lower end of the third vibration-damping spring 48 is fixed to the spring holder 46. When impact force is applied to the tip tool T by the impact force application mechanism 40, the first vibration-damping spring 45, the second vibration-damping spring 47, and the third vibration-damping spring 48 elastically deform, absorbing the vibrations generated during impact and suppressing the transmission of such vibrations to the handle 14A.

[0034] As shown in Figure 2, the cylinder case 43 is formed in a substantially cylindrical shape with the front-to-back direction as its axial direction. The rear end of the cylinder case 43 is connected to the front end of the motor case 42, so that the inside of the cylinder case 43 and the inside of the motor case 42 are in communication. The cylinder case 43 is arranged coaxially with the front housing portion 16 and is housed within the front housing portion 16. A retainer sleeve 44 is provided on the front side of the cylinder case 43. The retainer sleeve 44 is formed in a substantially cylindrical shape with the front-to-back direction as its axial direction and is arranged coaxially with the cylinder case 43. The rear end of the retainer sleeve 44 is fitted into the front end of the cylinder case 43, and the retainer sleeve 44 is connected so that it can move integrally with the cylinder case 43. The retainer sleeve 44 protrudes forward from the front housing portion 16. The tip tool T is attached to the front of the retainer sleeve 44 and protrudes forward from the retainer sleeve 44.

[0035] As shown in Figure 5, six contact ribs 43A are provided on the outer circumference of the cylinder case 43 at positions corresponding to the exposed holes 18A of the support base portion 18 in the front housing portion 16. The contact ribs 43A are formed in a rib shape that extends in the front-rear direction and protrude radially outward from the cylinder case 43. Specifically, the left and right pairs of contact ribs 43A provided at both ends of the cylinder case 43 in the left-right direction protrude outward from the cylinder case 43 in the left-right direction, with the vertical direction being the thickness direction. The left and right pairs of contact ribs 43A provided at the top of the cylinder case 43 protrude upward from the cylinder case 43 with the left-right direction being the thickness direction. The left and right pairs of contact ribs 43A provided at the bottom of the cylinder case 43 protrude downward from the cylinder case 43 with the left-right direction being the thickness direction.

[0036] (Regarding motor 50) As shown in Figure 2, the motor 50 is housed in the rear of the motor case 42. The motor 50 has a rotating shaft 50A whose axial direction is vertical. The rotating shaft 50A is rotatably connected to the motor case 42. A pinion gear 50B is formed at the upper end of the rotating shaft 50A. The motor 50 is electrically connected to a controller and is driven by the controller.

[0037] (Regarding the power transmission mechanism 52) The power transmission mechanism 52 is housed within the inner case 41. The power transmission mechanism 52 comprises a transmission gear 53, a crank mechanism 54, and a striking mechanism 60. The transmission gear 53 is positioned in front of the pinion gear 50B of the motor 50 and is rotatably connected to the motor case 42 with its vertical direction as the axial direction. A gear portion is formed on the outer circumference of the transmission gear 53, and this gear portion meshes with the pinion gear 50B of the motor 50.

[0038] The crank mechanism 54 comprises a crankshaft 55 and a crank gear 56. The crankshaft 55 is positioned in front of the transmission gear 53, with its vertical direction as the axial direction, and is rotatably connected to the motor case 42. The crank gear 56 is formed in a substantially disc shape with its vertical direction as the thickness direction. The central part of the crank gear 56 is integrally rotatably connected to the upper end of the crankshaft 55. A gear portion is formed on the outer circumference of the crank gear 56, and this gear portion meshes with the gear portion of the transmission gear 53.

[0039] A plate portion 55A is provided at the lower end of the crankshaft 55, and the plate portion 55A is formed in a substantially disc shape with the vertical direction being the thickness direction. An eccentric shaft 55B is provided on the plate portion 55A. The eccentric shaft 55B is formed in a substantially cylindrical shape with the vertical direction being the axial direction, and protrudes downward from the plate portion 55A. The eccentric shaft 55B is positioned eccentrically with respect to the central axis of the crankshaft 55.

[0040] The striking mechanism 60 comprises a piston 61, a striking element 63, an intermediate element 64, and a cylinder 65. The cylinder 65 is formed in a cylindrical shape with its axial direction in the front-rear direction. The cylinder 65 is housed in a cylinder case 43 and is positioned coaxially with the cylinder case 43. The cylinder 65 is fixed to an inner case 41. The piston 61 is formed in a substantially cylindrical shape with its axial direction in the front-rear direction and is inserted into the rear of the cylinder 65 so as to be relatively movable in the front-rear direction. The piston 61 is provided with a piston rod 62. The piston rod 62 extends in the front-rear direction, and its front end is rotatably connected to the piston 61 with its axial direction in the up-down direction, while its rear end is rotatably connected to an eccentric shaft 55B. As a result, when the motor 50 rotates, the piston 61 reciprocates in the front-rear direction by the crank mechanism 54.

[0041] The striking element 63 is formed in a substantially cylindrical shape with its axial direction in the front-rear direction. The striking element 63 is inserted into the cylinder 65 so as to be movable relative to the piston 61, and is positioned spaced apart in front of the piston 61. The space between the piston 61 and the striking element 63 within the cylinder 65 is the air chamber 65A. The intermediate element 64 is formed in a substantially cylindrical shape with its axial direction in the front-rear direction and is inserted into the retainer sleeve 44 so as to be movable relative to the piston 63 in the front-rear direction. The intermediate element 64 is positioned adjacent to the front of the striking element 63. As a result, when the piston 61 moves forward, the pressure in the air chamber 65A increases, causing the striking element 63 and the intermediate element 64 to move forward, and an impact force along the front-rear direction is applied to the tip tool T.

[0042] (Regarding the metal support cylinder 20) As shown in Figures 2, 5, and 6, the metal support cylinder 20 is made of metal. The metal support cylinder 20 is formed in a substantially cylindrical shape with the front-rear direction as its axial direction. The metal support cylinder 20 is positioned coaxially with the support base portion 18 in the front housing portion 16 and adjacent to the radially outer side of the support base portion 18, and is integrally formed with the front housing portion 16 by insert molding. As a result, the exposed hole 18A of the support base portion 18 is closed by the metal support cylinder 20. The metal support cylinder 20 is positioned adjacent to the rear side of the flange portion 16A of the front housing portion 16, and also adjacent to the front side of the protruding portion 16B of the front housing portion 16. The outer circumferential surface (surface) of the metal support cylinder 20 is configured as a mounting surface for attaching the sub-handle 70, which will be described later.

[0043] The metal support cylinder 20 is provided with multiple (six in this embodiment) inner metal exposed portions 20A at positions corresponding to the exposed holes 18A of the support base portion 18. The inner metal exposed portions 20A are raised radially inward and positioned inside the exposed holes 18A, and are curved along the circumferential direction of the metal support cylinder 20 when viewed from the front-to-back direction. That is, in the metal support cylinder 20, the thickness of the portion where the inner metal exposed portions 20A are provided is thicker than the thickness of the other portions. Furthermore, the outer shape of the inner metal exposed portions 20A is set so that, when viewed from the radially inward side of the metal support cylinder 20, the inner metal exposed portions 20A fill the entire exposed hole 18A. The inner metal exposed portions 20A are exposed radially inward from the exposed holes 18A of the support base portion 18. Thus, the inner metal exposed portions 20A and the support base portion 18 are alternately arranged in the circumferential direction of the support base portion 18.

[0044] As described above, the sum of the lengths L1 of the multiple exposed holes 18A in the circumferential direction of the support base portion 18 is set to less than half of the total circumferential length of the support base portion 18. Therefore, the sum of the lengths L1 of the multiple inner metal exposed portions 20A in the circumferential direction of the support base portion 18 is set to less than half of the total circumferential length of the support base portion 18. The contact rib 43A of the cylinder case 43, as described above, contacts the inner circumferential surface (back surface) of the inner metal exposed portion 20A, and the cylinder case 43 is supported by the metal support cylinder 20 so as to be movable in the front-rear direction. The tip of the contact rib 43A is formed along the circumferential direction of the support base portion 18 when viewed from the front-rear direction, and the contact rib 43A and the inner metal exposed portion 20A are in surface contact. In addition, the inner circumferential surface of the inner metal exposed portion 20A protrudes slightly radially inward from the inner circumferential surface (back surface) of the support base portion 18. Therefore, the contact rib 43A is set so as not to come into contact with the inner circumferential surface of the front housing portion 16.

[0045] A first flange portion 20B is formed at the front end of the outer circumferential surface of the metal support cylinder 20. The first flange portion 20B extends along the circumferential direction of the metal support cylinder 20 and is formed around the entire circumference of the metal support cylinder 20. The diameter of the first flange portion 20B is set so that it does not protrude radially outward from the flange portion 16A of the front housing portion 16. A second flange portion 20C is formed at the rear end of the outer circumferential surface of the metal support cylinder 20. The second flange portion 20C extends along the circumferential direction of the metal support cylinder 20 and is formed around the entire circumference of the metal support cylinder 20. The diameter of the second flange portion 20C is set so that it does not protrude radially outward from the overhang portion 16B of the front housing portion 16.

[0046] (Regarding sub-handle 70) As shown in Figures 1, 2, and 5, the sub-handle 70 comprises a first clamping member 71, a second clamping member 72, a handle portion 73, a connecting shaft 74, and an operating knob 75. The first clamping member 71 is formed in a substantially C-shaped block form that opens downward when viewed from the front-rear direction, and is positioned radially outward from the upper part of the metal support cylinder 20. The second clamping member 72 is formed in a substantially C-shaped block form that opens upward when viewed from the front-rear direction, and is positioned radially outward from the lower part of the metal support cylinder 20. The right ends of the first clamping member 71 and the second clamping member 72 are rotatably connected with the front-rear direction as the axial direction. The left ends of the first clamping member 71 and the second clamping member 72 protrude to the left of the metal support cylinder 20.

[0047] The handle portion 73 is formed in a substantially U-shape that is open to the front. An upper support portion 73A and a lower support portion 73B are provided at the front end of the handle portion 73. The upper support portion 73A and the lower support portion 73B are formed in a substantially cylindrical shape with the vertical direction as the axial direction, and the axial length of the lower support portion 73B is longer than the axial length of the upper support portion 73A. The upper support portion 73A is positioned above the left end of the first clamp member 71, and the lower support portion 73B is positioned below the left end of the second clamp member 72.

[0048] The connecting shaft 74 extends in the vertical direction. The upper end of the connecting shaft 74 is fixed to the upper support portion 73A of the handle portion 73, and the connecting shaft 74 extends downward from the upper support portion 73A and passes through the left end of the first clamp member 71, the left end of the second clamp member 72, and the lower support portion 73B. A threaded portion 74A is formed on the outer circumference of the connecting shaft 74.

[0049] The operating knob 75 is formed in a substantially cylindrical shape with its axial direction being vertical. A nut 76 is provided inside the operating knob 75, and the nut 76 is positioned coaxially with the operating knob 75. The operating knob 75 is positioned adjacent to the lower side of the lower support portion 73B of the handle portion 73, and the threaded portion 74A of the connecting shaft 74 is screwed into the nut 76. As a result, when the operating knob 75 is rotated, the operating knob 75 is displaced upward, and the upper support portion 73A and the lower support portion 73B clamp the left ends of the first clamp member 71 and the second clamp member 72 in the vertical direction, thereby clamping the metal support cylinder 20 with the first clamp member 71 and the second clamp member 72. In other words, the sub-handle 70 is attached to the metal support cylinder 20 of the housing 10 and is supported by the metal support cylinder 20. Furthermore, by rotating the sub-handle 70 in the circumferential direction of the metal support cylinder 20 and sliding the first clamp member 71 and the second clamp member 72 on the outer circumferential surface of the metal support cylinder 20, the position of the handle portion 73 in the circumferential direction of the metal support cylinder 20 can be changed.

[0050] (Effects and Benefits) Next, the operation and effects of this embodiment will be described.

[0051] In the hammer 1 configured as described above, the sub-handle 70 is attached to the metal support cylinder 20 of the housing 10. When performing fracture treatment or other processes on a workpiece using the hammer 1, the operator grasps the handle 14A with one hand and the handle portion 73 of the sub-handle 70 with the other hand. The operator then presses the tip tool T against the workpiece located at the front. As a result, the inner case 41 is displaced to the rear against the biasing forces of the first vibration damping spring 45, the second vibration damping spring 47, and the third vibration damping spring 48. That is, the contact rib 43A of the inner case 41 slides on the inner metal exposed portion 20A of the metal support cylinder 20, causing the inner case 41 to move relative to the housing 10 to the rear. In other words, the inner case 41 is biased forward by the first vibration-damping spring 45, the second vibration-damping spring 47, and the third vibration-damping spring 48, and is in a floating state relative to the housing 10. In this state, when the trigger 32 is pulled, the power transmission mechanism 52 is activated by the driving force of the motor 50, and an impact force in the front-rear direction is applied to the tip tool T. Furthermore, when an impact force is applied to the tip tool T while the inner case 41 is floating, the inner case 41 is displaced relative to the housing 10, and the first vibration-damping spring 45, the second vibration-damping spring 47, and the third vibration-damping spring 48 undergo elastic deformation. As a result, the vibrations generated during impact are absorbed by the elastic deformation of the first vibration-damping spring 45, the second vibration-damping spring 47, and the third vibration-damping spring 48, and the transmission of these vibrations to the handle 14A is suppressed.

[0052] In the hammer 1, the orientation of the sub-handle 70 can be changed by rotating the sub-handle 70 relative to the housing 10. When the orientation of the sub-handle 70 is changed, the first clamping member 71 and the second clamping member 72 of the sub-handle 70 slide on the outer circumferential surface of the housing 10, which may cause wear on the outer circumferential surface of the housing 10. In addition, in the hammer 1, the inner case 41 is supported so as to be movable relative to the housing 10. Therefore, when the inner case 41 moves relative to the housing 10, the inner case 41 slides on the inner circumferential surface of the housing 10, which may cause wear on the inner circumferential surface of the housing 10. If the housing 10 wears down, the support performance for the sub-handle 70 and inner case 41 will decrease, which may reduce the workability of the hammer 1.

[0053] Here, the housing 10 has a resin housing body 12 and a metal support cylinder 20. An exposed hole 18A is formed in the support base portion 18 of the housing body 12, and the inner metal exposed portion 20A of the metal support cylinder 20 is positioned within the exposed hole 18A, so that the metal support cylinder 20 is exposed from both sides FB in the front-back direction of the housing 10. That is, the outer circumference of the metal support cylinder 20 is exposed to the front side of the housing 10, and the inner metal exposed portion 20A of the metal support cylinder 20 is exposed to the back side of the housing 10. For this reason, in the hammer 1, the wear resistance of the housing 10 can be ensured by attaching the sub-handle 70 to the outer circumference of the metal support cylinder 20. Even if the sub-handle 70 is not attached, damage to the housing 10 in the event that the housing 10 comes into contact with a mating material can be suppressed. Furthermore, in the hammer 1, the wear resistance of the housing 10 can be ensured by supporting the inner case 41 with the inner circumference of the metal support cylinder 20. In other words, in the configuration of the hammer 1 in which the outer and inner circumferences of the housing 10 function as support parts, by having a metal support cylinder 20 function as the support part, the wear resistance of the housing 10 can be ensured and the decrease in the workability of the hammer 1 can be suppressed.

[0054] Furthermore, by positioning the inner metal exposed portion 20A of the metal support cylinder 20 within the exposed hole 18A, and configuring the contact rib 43A of the inner case 41 (cylinder case 43) to contact the inner metal exposed portion 20A, the weight of the front housing portion 16, including the metal support cylinder 20, can be reduced. That is, for example, by omitting the exposed hole 18A in the support base portion 18 and integrally providing a metal cylindrical member on the radially inner side of the support base portion 18, the contact rib 43A of the cylinder case 43 can be supported by the metal cylindrical member. In this case, a metal cylindrical member is required in addition to the metal support cylinder 20, which leads to an increase in the number of parts and an increase in the weight of the housing 10. In contrast, in this embodiment, by forming the exposed hole 18A in the support base portion 18, the inner circumference of the metal support cylinder 20 can be exposed radially inward of the support base portion 18. Therefore, compared to the above configuration, it is possible to reduce the number of parts and to lighten the front housing portion 16, including the metal support cylinder 20.

[0055] Furthermore, the metal support cylinder 20 is formed in a cylindrical shape with its axial direction in the front-rear direction, and is positioned adjacent to the radially outer side of the support base portion 18 of the front housing portion 16. The outer circumferential surface of the metal support cylinder 20 is continuously exposed over its entire circumference. Therefore, the entire outer circumferential portion of the metal support cylinder 20 can be configured as the mounting surface for the sub-handle 70. This ensures good support performance of the metal support cylinder 20 for the first clamp member 71 and the second clamp member 72 of the sub-handle 70.

[0056] Furthermore, the metal support cylinder 20 has a plurality of inner metal exposed portions 20A, and these multiple inner metal exposed portions 20A are intermittently exposed in the circumferential direction of the support base portion 18. That is, the support base portion 18 and the inner metal exposed portions 20A are arranged alternately in the circumferential direction of the support base portion 18. This allows the inner metal exposed portions 20A for supporting the inner case 41 (cylinder case 43) to be arranged in a balanced manner in the circumferential direction of the support base portion 18. Therefore, the support performance for the inner case 41 can be improved.

[0057] Furthermore, the metal support cylinder 20 is integrally formed with the support base portion 18 of the front housing portion 16 by insert molding. This reduces the assembly man-hours and the number of parts in the housing 10. Therefore, it can contribute to reducing the cost of the housing 10, and consequently, to reducing the cost of the hammer 1. In addition, by insert molding the metal support cylinder 20 into the front housing portion 16, the housing 10 can be made lighter compared to when the entire front housing portion 16, including the metal support cylinder 20, is made of metal, and consequently, the hammer 1 can be made lighter. From this point of view, the workability of the hammer 1 can be improved.

[0058] Furthermore, the sum of the lengths L1 of the multiple inner metal exposed portions 20A in the circumferential direction of the support base portion 18 is set to less than half of the total circumferential length of the support base portion 18. Therefore, in the metal support cylinder 20, the length of the portion formed integrally with the support base portion 18 can be secured while exposing the inner metal exposed portions 20A through the exposed holes 18A of the support base portion 18. In other words, in the resin support base portion 18, the area of ​​the portion where the exposed holes 18A are not formed can be secured, allowing the support base portion 18 and the metal support cylinder 20 to be formed integrally. This ensures the moldability of the front housing portion 16 which is formed integrally with the metal support cylinder 20.

[0059] Furthermore, the inner metal exposed portion 20A of the metal support cylinder 20 protrudes radially inward from the inner circumferential surface of the support base portion 18. This prevents the contact rib 43A of the cylinder case 43 from contacting the inner circumferential surface of the front housing portion 16. Therefore, for example, good sliding performance of the cylinder case 43 against the metal support cylinder 20 can be maintained.

[0060] In this embodiment, the outer circumferential surface of the metal support cylinder 20 is exposed along its entire circumference, and the inner circumferential surface (inner metal exposed portion 20A) of the metal support cylinder 20 is intermittently exposed along its circumference. Alternatively, the outer circumferential surface of the metal support cylinder 20 may be intermittently exposed along its circumference, and the inner circumferential surface of the metal support cylinder 20 may be continuously exposed along its circumference. In this case, for example, the metal support cylinder 20 is positioned radially inward of the support base portion 18, and the metal support cylinder 20 and the front housing portion 16 are formed integrally. Furthermore, an outer metal exposed portion is formed on the metal support cylinder 20 to be positioned in the exposure hole 18A, and the outer metal exposed portion is exposed radially outward from the exposure hole 18A. In addition, the outer circumferential surface of the outer metal exposed portion is positioned radially outward from the outer circumferential surface of the support base portion 18.

[0061] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. [Explanation of Symbols]

[0062] 10 Housing 12 Housing body (resin housing) 14A Handle 16 Front housing section (housing cylinder section) 18. Support base section (base section) 18A exposure hole 20 Metal support cylinder (metal housing) 20A Inner metal exposed part 40 Impact force application mechanism (drive mechanism section) 43 Cylinder Case 43A Contact rib (contact portion) 43B Cylinder contact area (contact area) 50 Motor (Drive Source) 52 Power transmission mechanism (transmission mechanism) 61 Pistons 65 cylinders 70 Sub-handle T Tip tool

Claims

1. A drive mechanism comprising a drive source and operating by the driving force of the drive source, A housing that covers at least a part of the drive mechanism and has a resin housing made of resin and a metal housing made of metal, Equipped with, The resin housing has an exposed hole that penetrates through the front and back sides of the resin housing. A work machine in which a portion of the metal housing is positioned within the exposed hole and exposed from both the front and back sides of the housing.

2. The aforementioned drive mechanism is A cylinder extending in a predetermined direction, A piston provided inside the cylinder and reciprocating along the predetermined direction, A cylinder case housing the aforementioned cylinder, It consists of, The resin housing has a cylindrical housing portion that extends in the predetermined direction, The metal housing is formed in a cylindrical shape extending in the predetermined direction, and is provided in the cylindrical portion of the housing. The work machine according to claim 1, wherein the cylinder case is housed inside the housing cylindrical portion and the metal housing.

3. The work machine according to claim 2, wherein one of the front and back surfaces of the metal housing is continuously exposed over the entire circumference of the metal housing, and the other of the front and back surfaces of the metal housing is intermittently exposed in the circumference of the metal housing.

4. The work machine according to claim 2, wherein the cylinder, the cylinder case, the housing cylindrical portion, and the metal housing are formed in a cylindrical shape with the predetermined direction as the axial direction and are arranged coaxially.

5. The housing cylindrical portion has a base portion, and the base portion has the exposed hole formed therein. The metal housing is positioned adjacent to the radially outer side of the base portion, and the outer circumferential surface of the metal housing is continuously exposed over the entire circumference of the metal housing. The work machine according to claim 4, wherein the metal housing is provided with an inner metal exposed portion, the inner metal exposed portion is positioned inside the exposure hole and exposed radially inward to the base portion.

6. The resin housing is provided with a handle. The work machine according to claim 5, wherein a sub-handle is detachably attached to the metal housing, and the surface of the metal housing is the mounting surface for the sub-handle.

7. The work machine according to claim 5 or 6, wherein the cylinder case is configured to be movable relative to the housing in the predetermined direction.

8. The outer circumferential surface of the cylinder case is provided with a contact portion that protrudes toward the inner metal exposed portion. The work machine according to claim 7, wherein the contact portion contacts the inner metal exposed portion and the cylinder is movably supported in the metal housing.

9. The inner metal exposed portion and the base portion are arranged alternately in the circumferential direction of the base portion. The work machine according to claim 8, wherein the cylinder is provided with a plurality of contact portions.

10. The work machine according to claim 8, wherein the inner metal exposed portion protrudes radially inward from the base portion of the metal housing.

11. The metal housing is integrally formed with the base portion, The work machine according to claim 9, wherein the sum of the lengths of the plurality of inner metal exposed portions in the circumferential direction of the metal housing is less than half the circumferential length of the base portion.

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