Power tools

Abstract

To obtain a vibration damping effect without including a vibration damping function in an auxiliary handle itself.SOLUTION: A grinder 1 is attachable by screwing a side handle 60 to a nut member 34 provided on a lateral face of a gear housing 4. In addition, the nut member 34 is held by the gear housing 4 through an elastic body 35. According to this constitution, a vibration damping function can be imparted to a grinder 1 side.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to power tools such as polishers and grinders.

Background Art

[0002] Power tools such as polishers and grinders are provided with auxiliary handles (for example, side handles) for an operator to grip. Since the auxiliary handle is attached to the housing of the tool body, vibrations generated from the tool body are transmitted to the operator's hand through the auxiliary handle, deteriorating the usability. As a countermeasure against this, for example, Patent Document 1 discloses an invention of an anti-vibration handle in which a cushion rubber is provided between a threaded rod that generates a clamping force in a clamping band that clamps the tool body and a grip portion that houses the threaded rod, or a dynamic vibration absorber is provided inside the grip portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional power tools, those with an anti-vibration handle such as that of Patent Document 1 can obtain an anti-vibration effect, while those without an anti-vibration handle have a problem that they cannot obtain an anti-vibration effect.

[0005] Therefore, an object of the present disclosure is to provide a power tool capable of obtaining an anti-vibration effect even if the auxiliary handle itself does not have an anti-vibration function.

Means for Solving the Problems

[0006] To achieve the above objective, this disclosure provides a motor housing that extends in the front-rear direction and has a grip portion, with a spindle protruding downward at the front of the housing, and a tip tool that can be attached to the lower end of the spindle, A power tool is provided in which a nut member is housed in a mounting hole provided on the side of the housing, and an auxiliary handle can be attached by screwing it onto the nut member, An elastic body is interposed between the inner surface of the mounting hole and the nut member, thereby reducing vibrations transmitted from the housing to the nut member during operation with the tip tool. The nut member and the elastic body are attached to the mounting hole by a mounting member that is screwed into the mounting hole. Another configuration of the present disclosure includes a motor housed in a housing that extends in the front-rear direction and has a grip portion, with a spindle protruding downward at the front of the housing, and a tip tool that can be attached to the lower end of the spindle, A housing portion provided on the side of the housing and opening to the side , having a cylindrical nut portion A power tool that houses a nut member and allows an auxiliary handle to be attached to the nut member by screwing it in, The nut member is The upper and lower tangents of the nut portion. The nut member is housed in such a way that it can swing left and right around a pivot point provided within the housing, and an elastic body is interposed between the nut member and the housing on the left and right outer side of the nut member, so that vibrations transmitted from the housing to the nut member during operation with the tip tool can be reduced by the elastic deformation of the elastic body accompanying the swinging of the nut member. [Effects of the Invention]

[0007] According to this disclosure, since the nut member is elastically held on the housing side to which the auxiliary handle is attached, it becomes possible to provide vibration damping functionality to the power tool side. Therefore, even if the auxiliary handle itself does not have vibration damping functionality, vibration damping effects can be obtained, and a comfortable user experience can be maintained. [Brief explanation of the drawing]

[0008] [Figure 1] It is a perspective view of the grinder of Example 1. [Figure 2] It is a side view of the grinder of Example 1. [Figure 3] It is a central longitudinal sectional view of the grinder of Example 1. [Figure 4] It is a partial enlarged sectional view taken along line A-A of FIG. 2. [Figure 5] It is an exploded perspective view of the support mechanism part. [Figure 6] It is a partial enlarged sectional view taken along line B-B of FIG. 4. [Figure 7] It is a partial perspective view of the grinder of Example 1 with a side handle attached. [Figure 8] It is an enlarged sectional view of the front part at the position of line A-A of FIG. 2 in the grinder of Example 1 with a side handle attached. [Figure 9] It is a perspective view of the grinder of Example 2. [Figure 10] It is a side view of the grinder of Example 2. [Figure 11] It is a partial enlarged sectional view taken along line C-C of FIG. 10. [Figure 12] It is an exploded perspective view of the support mechanism part as viewed from the right side. [Figure 13] It is an exploded perspective view of the support mechanism part as viewed from the left side. [Figure 14] It is a partial enlarged sectional view taken along line D-D of FIG. 10. [Figure 15] It is a partial perspective view of the grinder of Example 2 with a side handle attached. [Figure 16] It is an enlarged sectional view of the front part at the position of line C-C of FIG. 10 in the grinder of Example 2 with a side handle attached.

Mode for Carrying Out the Invention

[0009] In one embodiment of the present disclosure, the elastic body may be arranged over the entire circumference of the nut member. According to this configuration, the vibration damping effect can be obtained evenly without unevenness in the circumferential direction of the nut member. In an embodiment of the present disclosure, an attachment member for attaching the nut member and the elastic body to the housing may be provided. According to this configuration, the nut member and the elastic body can be held in a stable state in the housing. In an embodiment of the present disclosure, the attachment member may be screwed onto the housing for attachment. According to this configuration, the attachment member can be easily attached to and detached from the housing, and the nut member and the elastic body can be easily replaced. In an embodiment of the present disclosure, the nut member may be prevented from rotating by the attachment member. According to this configuration, the elastically supported nut member can be easily prevented from rotating by using the attachment member. In an embodiment of the present disclosure, a detachment prevention member for preventing the attachment member from falling off may be provided on the housing. According to this configuration, the detachment of the attachment member can be suitably prevented.

[0010] In an embodiment of the present disclosure, the nut member may be rotatably coupled about a fulcrum provided on the housing, and an elastic body may be interposed between the nut member and the housing. According to this configuration, the nut member rotating about the fulcrum can be easily elastically held. In an embodiment of the present disclosure, a clearance may be set between the nut member and the fulcrum. According to this configuration, even if the nut member is coupled by the fulcrum, the vibration transmitted from the fulcrum to the nut member can be reduced. In an embodiment of the present disclosure, a second elastic body may be provided on the opposite side of the elastic body sandwiching the nut member in the rotational direction of the nut member. According to this configuration, the nut member rotating about the fulcrum can be elastically held in any rotational direction. In one embodiment of the present disclosure, the housing has a gear housing at its front portion on which a tip tool can be attached to the lower end of a spindle that protrudes downward, and the nut member may be provided on the side of the gear housing. This configuration allows for effective vibration isolation of auxiliary handles, such as those on grinders, where vibrations are generated at the front. [Examples]

[0011] The embodiments of this disclosure will be described below with reference to the drawings. Figure 1 is a perspective view showing a grinder, an example of a power tool. Figure 2 is a side view of the grinder, and Figure 3 is a longitudinal cross-sectional view of the grinder. The grinder 1 has a motor housing 2 that extends in the front-to-back direction. An intermediate housing 3, which is rectangular in front view, is assembled to the front of the motor housing 2. A gear housing 4 is assembled to the front of the intermediate housing 3. A grip housing 5 that extends in the front-to-back direction is assembled to the rear of the motor housing 2. The motor housing 2 has a cylindrical rear housing portion 6 and a front housing portion 7 that is rectangular in front view. The motor 8 is housed in the rear housing portion 6. The front housing portion 7 is connected to the gear housing 4 via an intermediate housing 3 by screws that are screwed in from the front of the gear housing 4.

[0012] The rotating shaft 9 of the motor 8 extends in the front-rear direction. The front part of the rotating shaft 9 protrudes into the gear housing 4, passing through the front housing 7 and the intermediate housing 3. A fan 10 is fixed to the rotating shaft 9 within the intermediate housing 3. A first bevel gear 11 is fixed to the front end of the rotating shaft 9 within the gear housing 4. A bearing box 12 is screwed to the lower part of the gear housing 4 from below. Inside the gear housing 4 and the bearing box 12, a spindle 13 is pivotally supported in the vertical direction. A second bevel gear 14, which meshes with the first bevel gear 11, is fixed to the spindle 13. The lower end of the spindle 13 protrudes downward from the bearing box 12. A disc-shaped cutting tool (e.g., a grinding wheel) 15 is mounted perpendicularly to the lower end of the spindle 13. A semicircular wheel cover 16, in plan view, is attached to the lower part of the bearing box 12, covering the rear of the cutting tool 15 from above and behind.

[0013] The grip housing 5 has a front grip section 20, a middle grip section 21, and a rear grip section 22. The front grip section 20 expands forward and is assembled to the outside of the rear housing section 6 of the motor housing 2. The middle grip section 21 has a smaller diameter than the front grip section 20 and houses a switch 23 inside. The rear grip section 22 expands rearward and houses a controller 24 and a terminal block 25 inside. A battery pack 26, which serves as the power source, is attached to the rear grip section 22. A switch lever 27 is provided on the underside of the motor housing 2 and the grip housing 5. The front end of the switch lever 27 is rotatably connected to the underside of the rear housing portion 6 and extends rearward to the underside of the middle grip portion 21. The switch 23 is turned ON by pushing the switch lever 27 upward.

[0014] As shown in Figures 4 and 5, bottomed mounting holes 30, 30 are provided symmetrically on the left and right sides of the gear housing 4. The mounting holes 30, 30 open slightly forward and outward on the left and right sides. A female threaded portion 31 is formed on the inner circumference of each mounting hole 30. A support mechanism portion 32 to which a side handle 60, which will be described later, is attached is provided in each mounting hole 30. Since the support mechanisms 32, 32 are symmetrical, the left support mechanism portion 32 will be described below. The support mechanism 32 comprises a washer 33, a nut member 34, an elastic body 35, a mounting ring 36, and a cover plate 37. All components except the elastic body 35 are made of metal. The elastic body 35 is made of an elastic material such as rubber. The washer 33 is housed at the bottom of the mounting hole 30. The nut member 34 is housed in the mounting hole 30 on the left side of the washer 33. The nut member 34 is cylindrical and has a female threaded portion 40 on its inner circumference. The nut member 34 comprises 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 at the left end of the nut member 34. 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 at the right end of the nut member 34.

[0015] The elastic body 35 is a cylindrical shape with two diameters, having a small diameter section 45 and a large diameter section 46 coaxially arranged. The small diameter section 45 is externally mounted on the nut member 34 to the right of the outer flange 41. The outer diameter of the small diameter section 45 is larger than the outer diameter of the outer flange 41 of the nut member 34. The small diameter section 45 has a pair of elastic side chamfers 47, 47 that fit onto the nut side chamfers 43, 43 of the nut member 34. The large-diameter portion 46 is integrally formed with the right end of the small-diameter portion 45. The large-diameter portion 46 is shaped to cover the inner flange 42 from the left side, except for the right end face. The elastic body 35 may be integrated with the nut member 34 by insert molding or the like, or it may be integrated by attaching a separately manufactured elastic body 35 to the nut member 34 as an exterior.

[0016] The mounting ring 36 comprises an outer ring portion 50 and an inner ring portion 51, and has a shorter axial length than the elastic body 35. The outer ring portion 50 has an inner diameter larger than the outer diameters of the outer flange 41 and inner flange 42 of the nut member 34. A pair of ring side chamfers 52, 52 are formed on the inner circumference of the outer ring portion 50, parallel to the flange side chamfers 44, 44 of the outer flange 41. A threaded portion 53 is formed on the outer circumference of the outer ring portion 50, which screws into the female threaded portion 31 of the mounting hole 30. Grooves 54, 54 are formed on the left end face of the outer ring portion 50 in the diametrical direction. The grooves 54, 54 are for rotating the mounting ring 36 with a tool or the like. 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 circular hole 55 has a smaller diameter than the outer ring portion 50 of the mounting ring 36 and a larger diameter than the outer flange 41 of the nut member 34. A pair of small holes 56, 56 are formed above and below the circular hole 55. A flat receiving surface 17 is formed on the left side of the gear housing 4 to receive the cover plate 37. A pair of screw holes 18, 18 corresponding to the small holes 56, 56 are formed on the receiving surface 17.

[0017] The support mechanism 32 is assembled as follows. First, with the washer 33 and the nut member 34, which has the elastic body 35 integrated into the outer casing, housed in the mounting hole 30, the mounting ring 36 is fitted from the outside. At this time, the ring side grooves 52, 52 of the outer ring portion 50 are aligned with the flange side grooves 44, 44 of the outer flange 41. Then, the threaded portion 53 is screwed into the female threaded portion 31 to screw in the mounting ring 36. As a result, the mounting ring 36 is screwed into the depths of the mounting hole 30 while rotating the nut member 34 and the elastic body 35 together. Screwing is completed when the inner ring portion 51 contacts the washer 33. In this state, as shown in Figure 6, the ring side grooves 52, 52 of the outer ring portion 50 overlap the inner flange 42 of the nut member 34 when viewed in the axial direction. Therefore, the nut member 34 is pressed against the washer 33 via the elastic body 35 and prevented from coming off. In this way, the nut member 34 is elastically held around its entire circumference by the elastic body 35 within the mounting hole 30. Finally, the cover plate 37 is placed against the receiving surface 17 with the nut member 34 positioned within the circular hole 55, and the screws 57, 57 that pass through the small holes 56, 56 are screwed into the screw holes 18, 18. As a result, 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] As shown in Figures 7 and 8, the side handle 60 attached to the support mechanism 32 comprises a resin grip portion 61 and a screw shaft 62 that is held by the grip portion 61 and protrudes from the grip portion 61. Therefore, when using the side handle 60, the screw shaft 62 is screwed into the nut member 34 of the support mechanism 32 on either the left or right side (in this case, the left side). The side handle 60 is then connected to the gear housing 4 via the nut member 34. When screwing in the screw shaft 62, the rotation of the nut member 34 is restricted because the flange side grooves 44, 44 of the outer flange 41 fit into the ring side grooves 52, 52 of the mounting ring 36. Consequently, even with the elastic body 35 present, the screw shaft 62 can be screwed into the nut member 34 without any problems. The same applies when removing it.

[0019] In the grinder 1 configured as described above, the user turns on the switch 23 by pressing the switch lever 27 with the hand that is gripping the middle grip portion 21 of the grip housing 5. This causes the controller 24 to drive the motor 8. As a result, the rotation of the rotating shaft 9 is transmitted to the spindle 13 via the first and second bevel gears 11 and 14. In this way, grinding of the workpiece becomes possible with the tip tool 15 that rotates integrally with the spindle 13. During this operation, vibrations may occur due to the tip tool 15 or the motor 8. However, since an elastic body 35 is interposed between the nut member 34 to which the side handle 60 is connected and the gear housing 4, the vibrations transmitted to the side handle 60 are reduced. Therefore, the operator gripping the grip portion 61 is less likely to experience discomfort due to vibrations in their hand.

[0020] The grinder 1 in the above embodiment 1 can be attached by screwing a side handle 60 (an example of an auxiliary handle) onto a nut member 34 provided on the side of the gear housing 4 (an example of a housing). The nut member 34 is held in place by the gear housing 4 via the elastic body 35. With this configuration, the nut member 34 is elastically held on the gear housing 4 side to which the side handle 60 is attached, thus providing vibration damping functionality to the grinder 1 side. Therefore, even if the side handle 60 itself does not have vibration damping functionality, vibration damping effects can be obtained, and a comfortable user experience can be maintained.

[0021] The elastic body 35 is arranged around the entire circumference of the nut member 34. Therefore, a vibration damping effect can be obtained uniformly and evenly in the circumferential direction of the nut member 34. An attachment ring 36 (an example of an attachment member) is provided for attaching the nut member 34 and the elastic body 35 to the gear housing 4. Therefore, the nut member 34 and the elastic body 35 can be held in a stable state in the gear housing 4. The mounting ring 36 is attached to the gear housing 4 by screwing it into place. Therefore, the mounting ring 36 can be easily attached to and detached from the gear housing 4, and the nut member 34 and elastic body 35 can also be easily replaced. The nut member 34 is prevented from rotating by the mounting ring 36. Therefore, the elastically supported nut member 34 can be easily prevented from rotating using the mounting ring 36.

[0022] The gear housing 4 is provided with a cover plate 37 (an example of a detachment prevention member) to prevent the mounting ring 36 from falling off. Therefore, the loosening or detachment of the screw-in mounting ring 36 can be effectively prevented. The housing has a gear housing 4 at its front, on which a tip tool 15 can be attached to the lower end of a spindle 13 that protrudes downward. The nut member 34 is provided on the side of the gear housing 4. Therefore, effective vibration isolation becomes possible for the side handle 60 of the grinder 1, which generates vibrations at the front.

[0023] In the above embodiment 1, the shapes of the nut member and the elastic body can be changed as appropriate. For example, the nut component may have no outer flange. In this case, the nut side groove provided on the nut component can be fitted into the ring side groove of the mounting ring. The integration of the nut member and the elastic body in the rotational direction is not limited to utilizing the width across two surfaces created by the chamfered portion. For example, the cross-sectional shapes of the nut member and the elastic body may be polygonal, such as a square or hexagon, and the two may be integrated in the rotational direction. The elastic body is not limited to a cylindrical shape. The elastic body may have a C-shaped cross-section, with a portion of its circumference divided by a slit. Multiple elastic bodies may be arranged around the nut member. In this case, the elastic bodies may be ball-shaped or needle-shaped. The mounting ring is not limited to the two-sided width shown in the example above, as long as it has a shape that fits onto the nut member. Similar to the integration of the nut member and the elastic body, the cross-sectional shape may be a polygon such as a square or hexagon to fit the two together. A hole may be provided instead of a groove on the end face. The mounting ring may be attached to the gear housing by a structure other than screwing (for example, a locking structure with a locking part and a locked part). However, the mounting ring can be omitted. The anti-detachment component is not limited to a cover plate. The mounting ring may be held in place from the outside using multiple anti-detachment components that are screwed to the gear housing. However, the anti-detachment component can be omitted. [Examples]

[0024] Next, other embodiments of the present disclosure will be described. However, since the configuration of the grinder, etc., is the same as in Embodiment 1 except for the support mechanism, redundant explanations will be omitted and the explanation will focus on the support mechanism. Figure 9 is a perspective view of the grinder, Figure 10 is a side view, and Figure 11 is an enlarged cross-sectional view of a portion of the CC line in Figure 10. In the grinder 1A, a cylindrical portion 65 is formed inside the gear housing 4, from which the rotating shaft 9 protrudes. On both the left and right sides of the cylindrical portion 65, there are housing portions 66, 66, each with a circular opening 67, 67 on its left and right sides. A support mechanism portion 70 is housed in each housing portion 66. Here again, the support mechanisms 70, 70 are symmetrical, so the left support mechanism portion 70 will be described below.

[0025] As shown in Figures 12 and 13, 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 pivot pin 75. The nut member 71 is plate-shaped and extends in the front-rear direction, with a nut portion 76 positioned perpendicularly towards the rear. The nut portion 76 is cylindrical and protrudes from the left side of the nut member 71, with a female threaded portion 77 formed on its inner circumference. A boss portion 78 is formed on the right side of the front part of the nut member 71. A support hole 79 is formed through the center of the boss portion 78 in the vertical direction. On the rear side of the nut portion 76, a through hole 80 smaller in diameter than the female thread portion 77 is formed perpendicularly in the nut member 71. On the right side of the nut member 71, a pair of support ribs 81, 81 projecting to the right are provided above and below the through hole 80.

[0026] The first elastic body 72 is positioned to the left of the nut member 71. The first elastic body 72 is a short cylindrical shape that is fitted over the nut portion 76 and is made of an elastic material such as rubber. The first elastic body 72 is formed to be longer in the axial direction than the protruding length of the nut portion 76. The outer diameter of the first elastic body 72 is smaller than the opening 67 of the housing portion 66. A flange 82 is provided around the right end of the first elastic body 72. When the flange 82 is fitted over the nut portion 76, it 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 positioned to the right of the nut member 71. The second elastic body 73 comprises a plate portion 85 and a spherical portion 86 protruding to the right from the plate portion 85, and is made of an elastic material such as rubber. The plate portion 85 has a rectangular shape that fits between the support ribs 81 and 86 of the nut member 71. A bottomed 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 and 86, and the right end of the connecting pin 74 is inserted into the bottomed hole 87. Then, the second elastic body 73 is connected to the nut member 71 by the connecting pin 74, which spans both the through hole 80 and the bottomed hole 87. In this state, the spherical portion 86 protrudes to the right from the nut member 71. In the gear housing 4, insertion holes 68, 68 are formed at the upper and lower positions of the front of the housing portion 66, as shown in Figure 14. The pivot pin 75 is inserted from above into the insertion holes 68, 68 and passes through the housing portion 66. The pivot pin 75 has its upper portion 75a press-fitted into the upper insertion hole 68. The lower portion 75b of the pivot pin 75, which passes through the housing portion 66, is smaller in diameter than the upper portion 75a and smaller in diameter than the support hole 79 of the nut member 71.

[0028] The support mechanism 70 is assembled as follows. A first elastic body 72 is attached to the left side of the nut member 71, and a second elastic body 73 is attached to the right side via a connecting pin 74. Next, the nut member 71 is housed in the housing 66 with the boss portion 78 facing forward. Then, the support hole 79 is aligned with the upper and lower insertion holes 68, 68, and the pivot pin 75 is inserted from the upper side of the gear housing 4, straddling each of the holes 79, 68. As shown in Figure 14, the nut member 71 is then supported within the housing 66 so as to be able to swing left and right around the pivot pin 75. The lower end of the pivot pin 75 abuts against the upper surface of the bearing box 12, preventing it from coming out downwards. In this state, the first elastic body 72 is positioned at the center of the opening 67 of the housing portion 66, causing the flange 82 to abut 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. Thus, the nut member 71 is elastically supported within the housing portion 66 via the first and second elastic bodies 72 and 73.

[0029] Since the lower portion 75b of the pivot pin 75 has a smaller diameter than the support hole 79 of the nut member 71, a clearance C is created between the lower portion 75b and the support hole 79. Therefore, the nut member 71 can be easily assembled using the pivot pin 75. In addition, vibrations from the gear housing 4 are less likely to be transmitted to the nut member 71 via the pivot pin 75. Even with the clearance C, the rattle of the nut member 71 is restricted by the first and second elastic bodies 72 and 73. When using the side handle 60, the screw shaft 62 is screwed into the nut portion 76 of the support mechanism portion 70 on either the left or right side (in this case, the left side). Then, as shown in Figures 15 and 16, the side handle 60 is connected to the gear housing 4 via the nut member 71.

[0030] In the grinder 1A configured as described above, the switch is turned ON by pressing the switch lever 27 with the hand that is gripping the middle grip portion 21 of the grip housing 5. This causes the controller 24 to drive the motor 8. As a result, the rotation of the rotating shaft 9 is transmitted to the spindle 13 via the first and second bevel gears 11 and 14, causing the tip tool 15 to rotate. Grinding of the workpiece can then be performed using the rotating tip tool 15. During this operation, vibrations may occur due to the tip tool 15 or the motor 8. However, since the first and second elastic bodies 72 and 73 are interposed between the nut member 71 to which the side handle 60 is connected and the gear housing 4, the vibrations transmitted to the side handle 60 are reduced. Therefore, the operator gripping the grip portion 61 is less likely to experience discomfort due to vibrations in their hand.

[0031] The grinder 1A in the above embodiment 2 can be attached by screwing the side handle 60 onto the nut member 71 provided on the side of the gear housing 4. The nut member 71 is then held in place by the gear housing 4 via a first elastic body 72 (an example of an elastic body). With this configuration, the nut member 71 is elastically held on the gear housing 4 side to which the side handle 60 is attached, thus providing vibration damping functionality to the grinder 1A side. Therefore, even if the side handle 60 itself does not have vibration damping functionality, vibration damping effects can be obtained, and a comfortable user experience can be maintained.

[0032] The first elastic body 72 is arranged around the entire circumference of the nut portion 76 of the nut member 71. Therefore, a uniform vibration damping effect can be obtained evenly and without unevenness in the circumferential direction of the nut portion 76. The nut member 71 is rotatably connected to a pivot pin 75 (an example of a pivot point) provided on the gear housing 4, and a first elastic body 72 is interposed between the nut member 71 and the gear housing 4. Therefore, the nut member 71, which rotates around the pivot pin 75, can be easily elastically held in place. A clearance C is provided between the nut member 71 and the pivot pin 75. Therefore, even when the nut member 71 is connected by a pivot pin 75, the vibration transmitted from the pivot pin 75 to the nut member 71 can be reduced.

[0033] On the opposite side of the first elastic body 72 that sandwiches the nut member 71 in the rotational direction of the nut member 71, a second elastic body 73 (an example of a second elastic body) is provided. Therefore, the nut member 71, which rotates around the pivot pin 75, can be elastically held in any direction of rotation. The housing has a gear housing 4 at its front, on which a tip tool 15 can be attached to the lower end of a spindle 13 that protrudes downward. The nut member 71 is provided on the side of the gear housing 4. Therefore, effective vibration isolation becomes possible for the side handle 60 of the grinder 1A, where vibrations occur at the front.

[0034] In the above embodiment 2, the shape of the nut member is not limited to the example above. For example, the nut member may not be entirely plate-shaped, but may have a structure in which a cylindrical portion through which a pivot pin passes is tangentially connected to a cylindrical nut portion. The pivot point is not limited to a structure using a pivot pin. For example, a pivot pin may be integrally formed with a nut member and fitted into a recess provided inside the gear housing. Conversely, a pin portion may be provided inside the gear housing and fitted into a recess provided in the nut member. The pivot point is not limited to being positioned on the front side of the nut member as in the example above. The pivot point may also be on the rear side, top side, or bottom side of the nut member. The first elastic body does not have to be cylindrical. The first elastic body may be held on the inner surface of the gear housing instead of by the nut member. Similarly, the second elastic body may be held inside the gear housing. The shape of the second elastic body can also be changed as appropriate. Other shapes can be used instead of the spherical part. However, the second elastic body can be omitted.

[0035] The following explains the changes common to each example. The power tool does not have to be a DC tool powered by a battery pack; it may also be an AC tool powered by commercial electricity. Power tools are not limited to grinders. This disclosure is applicable to other grinding and polishing tools such as polishers and sanders, and cutting tools such as circular saws and cutters, as long as they use an auxiliary handle. Therefore, power tools are not limited to electric tools. This disclosure can also be applied to air tools, engine tools, and the like. Therefore, the mounting position of the auxiliary handle is not limited to the gear housing. It may be the motor housing or any other housing. The orientation of the auxiliary handle is not limited to left or right. The shape of the auxiliary handle itself is also not limited to the above-mentioned side handle, as long as it can be screwed into a nut member. For example, the grip portion may be ring-shaped. [Explanation of Symbols]

[0036] 1, 1A - Grinder, 2 - Motor housing, 4 - Gear housing, 5 - Grip housing, 8 - Motor, 9 - Rotating shaft, 13 - Spindle, 15 - Tip tool, 17 - Receiving surface, 30 - Mounting hole, 31, 40, 77 - Female thread section, 32, 70 - Support mechanism section, 33 - Washer, 34, 71 - Nut component, 35 - Elastic body, 36 - Mounting ring, 37 cover plate, 41 outer flange, 42 inner flange, 53 threaded section, 57 thread, 60 side handle, 61 grip section, 62 threaded shaft, 66 housing section, 67 opening, 72 first elastic body, 73 second elastic body, 74 connecting pin, 75 pivot pin, 76 nut section, 85 plate section, 86 spherical section.

Claims

1. A motor is housed in a housing that extends in the front-rear direction and has a grip portion, with a spindle protruding downward at the front of the housing, and a tip tool can be attached to the lower end of the spindle, A power tool is provided in which a nut member is housed in a mounting hole provided on the side of the housing, and an auxiliary handle can be attached by screwing it onto the nut member, A power tool characterized in that an elastic body is interposed between the inner surface of the mounting hole and the nut member, thereby reducing vibrations transmitted from the housing to the nut member during operation by the tip tool, and the nut member and the elastic body are attached to the mounting hole by a mounting member that is screwed into the mounting hole.

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

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

4. The power tool according to claim 3, wherein the elastic body is cylindrical and externally mounted on the nut member, and the elastic body and the nut member, and the nut member and the mounting member, are prevented from rotating from each other by fitting together chamfered portions provided on each.

5. The power tool according to any one of claims 1 to 4, characterized in that the housing is provided with a detachment prevention member for preventing the mounting member from falling off.

6. A motor is housed in a housing that extends in the front-to-back direction and has a grip portion. A spindle protruding downward is provided at the front of the housing, and a tip tool can be attached to the lower end of the spindle. A power tool comprising a housing portion provided on the side of the housing and opening to the side thereof, which houses a nut member having a cylindrical nut portion, and an auxiliary handle that can be attached to the nut member by screwing it on, The nut member is housed so as to be able to swing left and right around a pivot point provided within the housing in the vertical direction of the tangent to the nut portion, and an elastic body is interposed between the nut member and the housing on the left and right outer side of the nut member, so that vibrations transmitted from the housing to the nut member during operation by the tip tool can be reduced by the elastic deformation of the elastic body accompanying the swing of the nut member.

7. The power tool according to claim 6, characterized in that a clearance is provided between the nut member and the pivot point to facilitate the assembly of the nut member to the pivot point and to reduce the transmission of vibrations from the pivot point to the nut member.

8. The power tool according to claim 6 or 7, characterized in that, on the opposite side of the elastic body that sandwiches the nut member in the direction of oscillation of the nut member, a second elastic body is provided on either the nut member or the inner surface of the housing portion, which elastically holds the nut member between itself and the elastic body.

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