Power tool

Abstract

A power tool is provided. An angle grinder (1) is configured to be mounted by screwing a side handle (60) to a nut member (34) provided on a side surface of a gear housing (4). The nut member (34) is held to the gear housing (4) by an elastic body (35). According to this configuration, the angle grinder (1) side is provided with a vibration-proof function. Accordingly, a vibration-proof effect can be obtained even if the auxiliary handle itself does not have a vibration-proof function.

Description

Technical Field

[0001] This invention relates to a power tool such as a polisher and grinder. Background Technology

[0002] Power tools such as polishing machines and grinding machines are equipped with auxiliary handles (e.g., side handles) for the operator to grip. Because the auxiliary handle is installed in the housing of the tool body, vibrations generated from the tool body are transmitted to the operator's hand through the auxiliary handle, resulting in a poor user experience. As a countermeasure, for example, Patent Document 1 discloses a technical solution for an anti-vibration handle, which provides a cushioning gum between the threaded operating rod and the grip portion, or provides a dynamic vibration absorber inside the grip portion, wherein the threaded operating rod generates a clamping force on the fastening band of the clamping tool body; and the grip portion accommodates the threaded operating rod. [Existing Technical Documents] [Patent Literature]

[0003] Patent Document 1: Japanese Patent Publication No. 4920900 Summary of the Invention [The technical problem that the invention aims to solve]

[0004] The power tools in the prior art have the following problems: on the one hand, power tools equipped with anti-vibration handles (anti-vibration handles) like those in Patent Document 1 can achieve anti-vibration effects, while power tools without anti-vibration handles cannot achieve anti-vibration effects.

[0005] Therefore, the purpose of this invention is to provide a power tool that can achieve a vibration-damping effect even if the auxiliary handle itself does not have a vibration-damping function.

[0006] To achieve the above objectives, the present invention provides a power tool that enables an auxiliary handle to be screwed onto a nut member disposed on the side surface of a housing for installation. The power tool is characterized in that the nut member is held in the housing by an elastomer. [Invention Effects]

[0007] According to the present invention, on the housing side where the auxiliary handle is installed, the nut member is elastically held, thus enabling the power tool side to have a vibration damping function. Therefore, even if the auxiliary handle itself does not have a vibration damping function, a vibration damping effect can be achieved, thereby maintaining a good user experience. Attached Figure Description

[0008] Figure 1 This is a perspective view of the grinding machine in Example 1. Figure 2 This is a side view of the grinding machine in Example 1. Figure 3 This is a central longitudinal sectional view of the grinding machine in Example 1. Figure 4 yes Figure 2 A partial enlarged sectional view of A-A. Figure 5 This is an exploded three-dimensional view of the support mechanism. Figure 6 yes Figure 4 A partially enlarged sectional view of B-B. Figure 7 This is a partial perspective view of the grinder of Embodiment 1, which is equipped with a side handle. Figure 8 The grinding machine of Embodiment 1, which is equipped with a side handle, is in Figure 2 An enlarged sectional view of the front part at position A-A. Figure 9 This is a perspective view of the grinding machine in Example 2. Figure 10 This is a side view of the grinding machine in Example 2. Figure 11 yes Figure 10 A partially enlarged sectional view of C-C. Figure 12 This is a three-dimensional exploded view of the support mechanism as seen from the right side. Figure 13 This is a three-dimensional exploded view of the support mechanism as seen from the left. Figure 14 yes Figure 10 A partially enlarged sectional view of D-D. Figure 15 This is a partial perspective view of the grinder of Embodiment 2, which is equipped with a side handle. Figure 16 The grinder of Embodiment 2, which is equipped with a side handle, is in Figure 10 An enlarged sectional view of the front part at position C-C. [Explanation of reference numerals in the attached figures] 1, 1A: Grinding machine; 2: Motor housing; 4: Gear housing; 5: Handle housing; 8: Motor; 9: Rotating shaft; 13: Main shaft; 15: Top tool; 17: Bearing surface; 30: Mounting hole; 31, 40, 77: Internal threaded part; 32, 70: Support mechanism part; 33: Washer; 34, 71: Nut component; 35: Elastomer; 36: Mounting ring; 37: Cover plate; 41: Outer flange; 42: Inner flange; 53: Threaded part; 57: Screw; 60: Side handle; 61: Grip part; 62: Threaded shaft; 66: Receiving part; 67: Opening; 72: First elastomer; 73: Second elastomer; 74: Connecting pin; 75: Pivot pin; 76: Nut part; 85: Plate part; 86: Ball part. Detailed Implementation

[0009] In one embodiment of the present invention, the elastomer may be arranged throughout the entire circumference of the nut component. According to this structure, vibration damping effect can be obtained uniformly and evenly in the circumferential direction of the nut component. In one embodiment of the present invention, a mounting component may be provided for mounting the nut component and the elastomer to the housing. This structure enables the nut component and the elastomer to remain in the housing under stable conditions. In one embodiment of the present invention, the mounting component may be a component that is installed by screwing onto the housing. According to this structure, the mounting components can be easily disassembled and assembled relative to the housing, and the nut components and elastomers can also be easily replaced. In one embodiment of the present invention, the nut component may be a component that is prevented from rotating by a mounting component. According to this structure, it is possible to easily prevent the rotation of the elastically supported nut component using mounting components. In one embodiment of the present invention, an anti-detachment component for preventing the installation component from falling off may be provided on the housing. This structure effectively prevents the mounting components from falling off.

[0010] In one embodiment of the present invention, the nut member may be engaged in a manner that allows it to rotate around a fulcrum portion provided on the housing, and an elastic body may be provided between the nut member and the housing. Based on this structure, a nut component that rotates around a fulcrum can be easily and elastically held. In one embodiment of the present invention, a clearance may be provided between the nut component and the fulcrum portion. According to this structure, even when the nut component is engaged through the fulcrum, the vibration transmitted from the fulcrum to the nut component can be reduced. In one embodiment of the present invention, a second elastic body may be provided on the opposite side of the elastic body separated from the nut member in the rotational direction of the nut member. According to this structure, a nut component that can be elastically maintained in any direction of rotation, rotating around the fulcrum. In one embodiment of the present invention, the housing may have a gear housing at the front, which can mount the top tool at the lower end of the downwardly protruding spindle, and the nut member is provided on the side surface of the gear housing. This structure enables effective vibration damping for auxiliary handles of grinding machines and other devices that vibrate at the front. [Example 1]

[0011] The embodiments of the present invention will now be described with reference to the accompanying drawings. Figure 1 This is a perspective view of a grinding machine as an example of a power tool. Figure 2 This is a side view of the grinding machine. Figure 3 This is a central longitudinal sectional view of the grinding machine. The grinder 1 has a motor housing 2 extending in the front-to-back direction. A middle housing 3, which appears quadrilateral when viewed from the front, is assembled on the front side of the motor housing 2. A gear housing 4 is assembled on the front side of the middle housing 3. A handle housing 5 extending in the front-to-back direction is assembled on the rear side of the motor housing 2. The motor housing 2 has a cylindrical rear housing portion 6 and a quadrilateral front housing portion 7 when viewed from the front. The motor 8 is housed inside the rear housing portion 6. The front housing portion 7 is connected to the gear housing 4 via an intermediate housing 3 by a screw screwed in from the front of the gear housing 4.

[0012] The rotating shaft 9 of the motor 8 extends in the front-to-back direction. The front part of the rotating shaft 9 passes through the front housing 7 and the intermediate housing 3 and protrudes into the gear housing 4. Inside the intermediate housing 3, a fan 10 is fixed on the rotating shaft 9. Inside the gear housing 4, a first bevel gear 11 is fixed at the front end of the rotating shaft 9. A bearing housing 12 is threadedly fastened from below to the lower part of the gear housing 4. A main shaft 13 is axially supported in the vertical direction inside the gear housing 4 and the bearing housing 12. A second bevel gear 14, which meshes with the first bevel gear 11, is fixed on the main shaft 13. The lower end of the spindle 13 protrudes downward from the bearing housing 12. A disc-shaped tip tool (e.g., a grinding wheel) 15 is orthogonally mounted at the lower end of the spindle 13. A wheel cover 16, which appears semi-circular when viewed from above, is mounted on the lower part of the bearing housing 12, and covers the rear of the tip tool 15 from above and rear.

[0013] The handle housing 5 has a front handle portion 20, a middle handle portion 21, and a rear handle portion 22. The front handle portion 20 extends forward and is assembled to the outside of the rear housing portion 6 of the motor housing 2. The diameter of the middle handle portion 21 is smaller than that of the front handle portion 20, and a switch 23 is housed inside it. The rear handle portion 22 extends rearward and houses a controller 24 and a terminal block 25 inside it. A battery pack 26 serving as a power source is installed in the rear handle portion 22. A switch operating handle 27 is provided on the lower side of the motor housing 2 and the handle housing 5. The front end of the switch operating handle 27 is rotatably connected to the lower surface of the rear housing 6 and extends rearward to the lower surface of the middle handle 21. The switch 23 is turned on by pressing the switch operating handle 27 upward.

[0014] like Figure 4 and Figure 5 As shown, bottomed mounting holes 30, 30 are symmetrically arranged on the left and right side surfaces of the gear housing 4. The mounting holes 30, 30 open slightly forward and outward in the left and right directions. An internal thread 31 is formed on the inner circumference of each mounting hole 30. A support mechanism 32 is provided in each mounting hole 30, which is used to mount the side handle 60 described later. Since the support mechanisms 32, 32 are symmetrical, the support mechanism 32 on the left side will be described below. The support mechanism 32 includes a washer 33, a nut component 34, an elastomer 35, a mounting ring 36, and a cover plate 37. All components except the elastomer 35 are made of metal. The elastomer 35 is formed of an elastic material such as rubber. Washer 33 is housed at the bottom of mounting hole 30. The nut member 34 is received in the mounting hole 30 on the left side of the washer 33. The nut member 34 is cylindrical with an internal thread 40 on its inner circumference. The nut member 34 has an outer flange 41 and an inner flange 42. A pair of parallel nut-side chamfers 43, 43 are formed on the outer circumferential surface of the nut member 34. The outer flange 41 is formed coaxially with the nut member 34 at its left end. A pair of flange-side chamfers 44, 44, parallel to the nut-side chamfers 43, 43, are also formed on the outer circumferential surface of the outer flange 41. The inner flange 42 has approximately the same outer diameter as the outer flange 41 and is formed coaxially with the nut member 34 at its right end.

[0015] The elastomer 35 is a cylindrical structure with a secondary diameter consisting of a small-diameter portion 45 and a large-diameter portion 46, which is larger than the small-diameter portion 45. The small-diameter portion 45 is mounted on the outside of the nut member 34, positioned to the right of the outer flange 41. The outer diameter of the small-diameter portion 45 is larger than the outer diameter of the outer flange 41 of the nut member 34. A pair of elastomer-side chamfered portions 47, 47 are formed on the small-diameter portion 45 to engage with the nut-side chamfered portions 43, 43 of the nut member 34. The large-diameter portion 46 and the right end of the small-diameter portion 45 are integrally formed. The large-diameter portion 46 is shaped to cover the portion of the inner flange 42 from the left side, excluding the right end face. The elastomer 35 can be integrated with the nut component 34 either by insert molding or by mounting the separately manufactured elastomer 35 on the outside of the nut component 34.

[0016] The mounting ring 36 has an outer ring portion 50 and an inner ring portion 51, and is shorter than the axial length of the elastomer 35. The outer ring portion 50 has an inner diameter larger than the outer diameter of the outer flange 41 and the inner flange 42 of the nut member 34. A pair of ring-side chamfered portions 52, 52 are formed on the inner circumference of the outer ring portion 50, parallel to the flange-side chamfered portions 44, 44 of the outer flange 41. A threaded portion 53 is formed on the outer circumference of the outer ring portion 50, which engages with the internal threaded portion 31 of the mounting hole 30. Grooves 54, 54 are formed on the left end face of the outer ring portion 50 along the diametrical direction. Grooves 54, 54 are used for rotating the mounting ring 36 by means of tools, etc. The inner diameter of the inner ring portion 51 is larger than the inner diameter of the outer ring portion 50. The outer diameter of the inner ring portion 51 is smaller than the outer diameter of the outer ring portion 50. The cover plate 37 has a circular hole 55 in the center. The diameter of the circular hole 55 is smaller than the diameter of the outer ring portion 50 of the mounting ring 36, but larger than the diameter of the outer flange 41 of the nut member 34. A pair of small holes 56, 56 are formed on the upper and lower sides of the circular hole 55. A flat bearing surface 17 for bearing the cover plate 37 is formed on the left side surface of the gear housing 4. A pair of threaded holes 18, 18 corresponding to the small holes 56, 56 are formed on the bearing surface 17.

[0017] The support mechanism 32 is assembled as follows. First, with the washer 33 and nut member 34 housed in the mounting hole 30, the mounting ring 36 is fitted from the outside, wherein an elastomer 35 is integrally mounted on the nut member 34. At this time, the chamfered portions 52, 52 on the annular side of the outer ring portion 50 are adapted to the chamfered portions 44, 44 on the flange side of the outer flange 41. Then, the threaded portion 53 is screwed into the internal threaded portion 31 to screw the mounting ring 36 in. Thus, the mounting ring 36 is screwed into the mounting hole 30 while the nut member 34 and elastomer 35 rotate integrally. The screwing action ends when the inner ring portion 51 abuts against the washer 33. In this state, as... Figure 6 As shown, the chamfered portions 52, 52 on the outer ring portion 50 overlap with the inner flange 42 of the nut member 34 when viewed axially. Therefore, the nut member 34 is pressed against the washer 33 by the elastic body 35 to prevent it from falling off. In this way, the nut member 34 is elastically held within the mounting hole 30 by the elastic body 35 throughout its circumference. Finally, the cover plate 37 is placed against the bearing surface 17 with the nut component 34 positioned within the circular hole 55, and the screws 57, 57 passing through the small holes 56, 56 are screwed into the threaded holes 18, 18. Thus, the mounting ring 36 is covered from the outside by the cover plate 37, preventing accidental rotation (loosening). Even if the mounting ring 36 becomes loose, it will not fall off the gear housing 4.

[0018] like Figure 7 and Figure 8 As shown, the side handle 60, which is mounted on the support mechanism 32, has a resin grip portion 61 and a threaded shaft 62 that is held in the grip portion 61 and protrudes from the grip portion 61. Therefore, when using the side handle 60, the threaded shaft 62 is screwed into the nut member 34 of the support mechanism portion 32 on either the left or right side (in this case, the left side). The side handle 60 then engages with the gear housing 4 via the nut member 34. When the threaded shaft 62 is screwed in, the nut member 34 is restricted from rotation by the flange-side chamfered portions 44, 44 of the outer flange 41 engaging with the ring-side chamfered portions 52, 52 of the mounting ring 36. Therefore, even with the presence of the elastic body 35, the threaded shaft 62 can be screwed into the nut member 34 without obstruction. The same applies to disassembly.

[0019] In the grinding machine 1 configured as described above, the switch 23 is activated by pressing the operating switch handle 27 with the hand holding the middle handle portion 21 of the handle housing 5. The controller 24 then drives the motor 8. Therefore, the rotation of the rotating shaft 9 is transmitted to the spindle 13 via the first bevel gear 11 and the second bevel gear 14. In this way, the workpiece can be ground using the tip tool 15, which rotates integrally with the spindle 13. During this operation, vibrations may sometimes occur due to the top tool 15 and the motor 8. However, since an elastic body 35 is provided between the nut member 34, which engages with the side handle 60, and the gear housing 4, the vibrations transmitted to the side handle 60 are reduced. Therefore, the operator's hand holding the handle 61 is less likely to experience discomfort due to vibration.

[0020] In the grinding machine 1 of the above embodiment 1, the side handle 60 (an example of an auxiliary handle) can be screwed onto the nut member 34 provided on the side surface of the gear housing 4 (an example of a housing) for installation. Furthermore, the nut component 34 is held in the gear housing 4 by the elastic body 35. According to this structure, since the nut member 34 is elastically held on the gear housing 4 where the side handle 60 is installed, the grinding machine 1 side can have a vibration damping function. Therefore, even if the side handle 60 itself does not have a vibration damping function, it can still achieve a vibration damping effect, thereby maintaining a good user experience.

[0021] The elastomer 35 is arranged around the entire circumference of the nut component 34. Therefore, vibration damping effect can be obtained uniformly and evenly in the circumferential direction of the nut component 34. An mounting ring 36 (an example of a mounting component) is provided for mounting the nut member 34 and the elastomer 35 to the gear housing 4. Therefore, the nut component 34 and the elastomer 35 can be held in the gear housing 4 in a stable state. Mounting ring 36 is installed by threading onto gear housing 4. Therefore, the mounting ring 36 can be easily installed and removed from the gear housing 4, and the nut component 34 and the elastomer 35 can also be easily replaced. Nut component 34 is prevented from rotating by mounting ring 36. Therefore, the installation ring 36 can be used to easily prevent the rotation of the elastically supported nut component 34.

[0022] A cover plate 37 (an example of an anti-detachment component) is provided on the gear housing 4 to prevent the mounting ring 36 from falling off. Therefore, it is possible to properly prevent the screw-in mounting ring 36 from loosening or falling off. The housing has a gear housing 4 at the front, which allows the top tool 15 to be mounted at the lower end of the downwardly protruding spindle 13. Furthermore, a nut member 34 is provided on the side surface of the gear housing 4. Therefore, the side handle 60 of the grinding machine 1, which vibrates at the front, can be effectively protected from vibration.

[0023] Furthermore, in the above embodiment 1, the shape of the nut component and the elastomer can be appropriately changed. For example, the nut component can also be a shape without an external flange. In this case, it is sufficient to make the nut-side chamfer on the nut component fit into the ring-side chamfer of the mounting ring. Integration of the nut component and the elastomer in the rotational direction is not limited to using the opposite width based on the chamfer. For example, the cross-sectional shape of the nut component and the elastomer can also be made into a polygon such as a quadrilateral or a hexagon to integrate them in the rotational direction. The elastomer is not limited to a cylindrical shape. An elastomer can also be C-shaped with a portion of its circumferential section interrupted by a slit. Multiple elastomers can also be arranged around the nut component. In this case, the elastomer can be spherical or needle-shaped. The mounting ring can fit into the shape of the nut component, and is not limited to the opposite width in the examples above. Similar to the integration of the nut component and the elastomer, the mounting ring and the nut component can have a polygonal cross-sectional shape such as a quadrilateral or hexagon to achieve a fit. A hole can also be provided instead of a groove on the end face. The mounting ring can also be mounted to the gear housing using a structure other than screwing (e.g., a locking structure achieved by a locking part and a locked part). However, the mounting ring can also be omitted. The anti-detachment component is not limited to the cover plate. Multiple anti-detachment components, screwed to the gear housing, can also be used to press the mounting ring from the outside. However, the anti-detachment component can also be omitted. [Example 2]

[0024] Next, another embodiment of the present invention will be described. However, since the structure of the grinding machine, except for the support mechanism, is the same as that of Embodiment 1, repeated descriptions will be omitted, and the description will focus on the support mechanism. Figure 9 It is a 3D diagram of a grinding machine. Figure 10 It is a side view. Figure 11 yes Figure 10 A partially enlarged sectional view of C-C. In the grinding machine 1A, a cylindrical portion 65 is formed inside the gear housing 4, through which the rotating shaft 9 protrudes. Receiving portions 66, 66 are formed on the left and right sides of the cylindrical portion 65, and these receiving portions 66, 66 have circular openings 67, 67 on their left and right side surfaces. Each receiving portion 66 houses a support mechanism portion 70. Since the support mechanisms 70, 70 are also symmetrical, the support mechanism portion 70 on the left side will be described below.

[0025] like Figure 12 and Figure 13 As shown, the support mechanism 70 includes a nut member 71, a first elastic body 72, a second elastic body 73, a connecting pin 74, and a fulcrum pin 75. The nut member 71 is a plate-shaped part extending in the front-rear direction, and has a nut portion 76 orthogonally positioned at the rear. The nut portion 76 is a cylindrical part protruding to the left surface of the nut member 71, and has an internal thread portion 77 formed on its inner circumference. A protrusion 78 is formed on the right surface of the front part of the nut member 71. A support hole 79 is formed through the center of the protrusion 78 in the vertical direction. A through hole 80, smaller in diameter than the internal thread portion 77, is formed orthogonally on the nut member 71 on the rear side of the nut portion 76. On the right surface of the nut member 71, a pair of support ribs 81, 81 protruding to the right are provided on the upper and lower sides of the through hole 80.

[0026] The first elastic body 72 is disposed on the left side of the nut member 71. The first elastic body 72 is a short cylindrical shape installed outside the nut portion 76 and is formed of an elastic material such as rubber. Axially, the protruding length of the first elastic body 72 is longer than the protruding length of the nut portion 76. The outer diameter of the first elastic body 72 is smaller than the diameter of the opening 67 of the receiving portion 66. A flange 82 is provided around the right end of the first elastic body 72. When externally mounted on the nut portion 76, the flange 82 abuts against the left surface of the nut member 71. The outer diameter of the flange 82 is larger than the opening 67. The second elastic body 73 is disposed on the right side of the nut member 71. The second elastic body 73 has a plate portion 85 and a spherical portion 86 protruding to the right from the plate portion 85, and is formed of an elastic material such as rubber. The plate portion 85 has a quadrilateral shape that fits between the support ribs 81, 81 of the nut member 71. A bottom hole 87 is formed on the left surface of the plate portion 85.

[0027] The left end of the connecting pin 74 is inserted into the through hole 80 of the nut member 71. In this state, the plate portion 85 of the second elastic body 73 is fitted between the support ribs 81, 81, and the right end of the connecting pin 74 is inserted into the bottom hole 87. Thus, the second elastic body 73 is connected to the nut member 71 by the connecting pin 74 that extends through the through hole 80 and the bottom hole 87. In this state, the ball portion 86 protrudes to the right from the nut member 71. In gear housing 4, such as Figure 14 As shown, insertion holes 68, 68 are formed at the upper and lower positions of the front part of the receiving part 66. The fulcrum pin 75 is inserted into the insertion holes 68, 68 from above, thereby penetrating the receiving part 66. The upper portion 75a of the fulcrum pin 75 is pressed into the upper insertion hole 68. The diameter of the lower portion 75b of the fulcrum pin 75 that passes through the receiving part 66 is smaller than the diameter of the upper portion 75a and smaller than the diameter of the support hole 79 of the nut member 71.

[0028] The support mechanism 70 is assembled as follows. The first elastic body 72 is installed on the left surface of the nut member 71, and the second elastic body 73 is installed on the right surface of the nut member 71 via the connecting pin 74. Next, the nut member 71 is received in the receiving portion 66 with the protrusion 78 facing forward. Then, the positions of the support hole 79 and the upper and lower insertion holes 68, 68 are aligned, and the fulcrum pin 75 is inserted through all holes 79, 68 from the upper side of the gear housing 4. Thus, as... Figure 14 As shown, the nut component 71 is supported within the housing 66 in a manner that allows it to swing left and right around the pivot pin 75. Since the lower end of the pivot pin 75 abuts against the upper surface of the bearing housing 12, it is possible to prevent the pivot pin 75 from falling downwards. In this state, the first elastic body 72 is located at the center of the opening 67 of the receiving portion 66, and the flange 82 abuts against the inner surface of the gear housing 4. At the same time, the second elastic body 73 causes the spherical portion 86 to abut against the outer surface of the cylindrical portion 65 inside the gear housing 4. Therefore, the nut member 71 is elastically supported in the receiving portion 66 by the first elastic body 72 and the second elastic body 73.

[0029] Because the diameter of the lower portion 75b of the fulcrum pin 75 is smaller than the diameter of the support hole 79 of the nut member 71, a gap C is generated between the lower portion 75b and the support hole 79. Therefore, the nut member 71 can be easily assembled via the fulcrum pin 75. In addition, vibrations of the gear housing 4 are less likely to be transmitted to the nut member 71 via the fulcrum pin 75. Furthermore, even if the gap C exists, the wobbling of the nut member 71 can be limited by the first elastic body 72 and the second elastic body 73. When using the side handle 60, the threaded shaft 62 is screwed into the nut 76 of the support mechanism 70 on either the left or right side (in this case, the left side). Thus, as... Figure 15 and Figure 16 As shown, the side handle 60 is engaged with the gear housing 4 via a nut member 71.

[0030] In the grinding machine 1A configured as described above, the switch is activated by pressing the operating switch lever 27 with the hand holding the middle handle portion 21 of the handle housing 5. The controller 24 then drives the motor 8. Consequently, the rotation of the rotating shaft 9 is transmitted to the main shaft 13 via the first bevel gear 11 and the second bevel gear 14, causing the tip tool 15 to rotate. In this way, the workpiece can be ground or otherwise processed by the rotating tip tool 15. During this operation, vibrations may sometimes occur due to the top tool 15 and the motor 8. However, because a first elastic body 72 and a second elastic body 73 are provided between the nut member 71 with the side handle 60 and the gear housing 4, the vibrations transmitted to the side handle 60 are reduced. Therefore, the operator's hand holding the handle 61 is less likely to experience discomfort due to vibration.

[0031] The grinding machine 1A of the above embodiment 2 can be installed by screwing the side handle 60 onto the nut member 71 provided on the side surface of the gear housing 4. Furthermore, the nut component 71 is held in the gear housing 4 by the first elastic body 72 (an example of an elastic body). According to this structure, since the nut member 71 is elastically held on the gear housing 4 where the side handle 60 is installed, the grinding machine 1A side can have a vibration damping function. Therefore, even if the side handle 60 itself does not have a vibration damping function, it can still achieve a vibration damping effect, thereby maintaining a good user experience.

[0032] The first elastic body 72 is arranged around the entire circumference of the nut portion 76 of the nut member 71. Therefore, a vibration damping effect can be obtained uniformly and evenly in the circumferential direction of the nut portion 76. The nut member 71 is engaged in a manner that allows it to rotate around a pivot pin 75 (an example of a pivot portion) provided on the gear housing 4, and a first elastic body 72 is provided between the nut member 71 and the gear housing 4. Therefore, the nut component 71 can be easily and elastically held in place to rotate around the pivot pin 75. A gap C is provided between the nut component 71 and the fulcrum pin 75. Therefore, even when the nut component 71 is engaged by the pivot pin 75, the vibration transmitted from the pivot pin 75 to the nut component 71 can be reduced.

[0033] A second elastic body 73 (an example of the second elastic body) is provided on the opposite side of the first elastic body 72, which is separated from the nut member 71, in the direction of rotation of the nut member 71. Therefore, the nut component 71 can be elastically maintained in any direction of rotation, rotating around the pivot pin 75. The housing has a gear housing 4 at the front, which allows the top tool 15 to be mounted at the lower end of the downwardly protruding spindle 13. Furthermore, a nut member 71 is provided on the side surface of the gear housing 4. Therefore, the side handle 60 of the grinding machine 1A, which vibrates at the front, can be effectively protected from vibration.

[0034] In Embodiment 2 described above, the shape of the nut component is not limited to the examples above. For example, the nut component may also have a structure in which the cylindrical nut portion is joined tangentially to a cylindrical portion for passing through the pivot pin, rather than being a plate-like structure. The fulcrum is not limited to a structure implemented by a fulcrum pin. For example, the fulcrum pin may be integrally formed on the nut member and engage with a recess provided inside the gear housing. Conversely, a pin may be provided inside the gear housing and engage with a recess provided on the nut member. The fulcrum is not limited to being positioned on the front side of the nut member as in the example above. The fulcrum can be positioned on the rear side of the nut member, or on the upper or lower side of the nut member. The first elastic body may not be cylindrical. The first elastic body may also be held on the inner surface of the gear housing instead of the nut member. The second elastic body may similarly be held within the gear housing. The shape of the second elastic body may also be appropriately modified. Other shapes may be used instead of the spherical portion. However, the second elastic body may be omitted.

[0035] The following explains the common variations in all examples. Power tools can also be AC ​​tools that use commercial power sources, rather than DC tools powered by battery packs. Power tools are not limited to grinders. This invention can also be applied to other grinding / sharpening tools such as polishers and grinders, as well as cutting tools such as circular saws and cutting machines, as long as they use auxiliary handles. Therefore, power tools are not limited to electric tools. This invention can also be used with pneumatic tools, engine-driven tools, etc. Therefore, the mounting location of the auxiliary handle is not limited to the gear housing. It can be the motor housing or other housings. The orientation of the auxiliary handle is also not limited to the left-right direction. As long as the shape of the auxiliary handle itself allows it to be screwed into the nut assembly, it is not limited to the aforementioned side handle. For example, the grip portion can also be ring-shaped.

Claims

1. A power tool comprising a downwardly projecting spindle at the front of a housing having a handle portion and housing a motor, extending in a front-rear direction; a tipping tool being mounted at the lower end of the spindle; and a nut member being accommodated in a mounting hole provided on a side surface of the housing, and an auxiliary handle being screwed onto the nut member for installation, characterized in that... An elastomer is provided between the inner surface of the mounting hole and the nut member. The elastomer can reduce the vibration transmitted from the housing to the nut member when the top tool is working. The nut member and the elastomer are mounted in the mounting hole by a mounting component that is screwed into the mounting hole.

2. The power tool according to claim 1, characterized in that, The elastomer is arranged around the entire circumference of the nut component.

3. The power tool according to claim 1 or 2, characterized in that, The nut component is prevented from rotating by the mounting component.

4. The power tool according to claim 3, characterized in that, The elastomer is a cylindrical shape installed on the outside of the nut component, and the elastomer and the nut component, as well as the nut component and the mounting component, are mutually prevented from rotating by the engagement between their respective chamfered portions.

5. The power tool according to any one of claims 1, 2, and 4, characterized in that, An anti-detachment component is provided on the housing to prevent the mounting component from falling off.

6. A power tool having a downwardly projecting spindle at the front of a housing that houses a motor and extends in a front-rear direction, and a tipping tool mounted at the lower end of the spindle; on the other hand, A nut member with a cylindrical nut portion is housed in a receiving portion provided on the side surface of the housing and having an opening on the side surface, and an auxiliary handle can be screwed onto the nut member for installation. Its features are, The nut component is housed in such a way that it can swing left and right around a pivot point located in the receiving portion in the vertical direction along the tangent of the nut portion. Furthermore, an elastic body is provided on the outer side of the nut component in the left and right directions and between the nut component and the housing. The elastic deformation of the elastic body accompanying the swing of the nut component can reduce the vibration transmitted from the housing to the nut component when the top tool is operating.

7. The power tool according to claim 6, characterized in that, A gap is provided between the nut component and the fulcrum portion, which facilitates the installation of the nut component onto the fulcrum portion and prevents the transmission of vibrations from the fulcrum portion to the nut component.

8. The power tool according to claim 6 or 7, characterized in that, A second elastic body is provided on the opposite side of the elastic body separated from the nut member in the swing direction of the nut member. The second elastic body elastically holds the nut member between the nut member and the inner surface of the receiving portion, on either side of the inner surface of the nut member and the elastic body.

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