Work machine

Abstract

To prevent deterioration of cover performance for a grinding wheel.SOLUTION: In a grinder 10, a guard clip 90 is configured to include a guard clip main body 92 and a protective cover 94. The guard clip main body 92 has: a clip portion 92A attached to a wheel guard 80; and a lower guard base portion 92B connected to the clip portion 92A. A protective cover 94 made of an elastic material covers an upper surface of the lower guard base portion 92B, and the protective cover 94 and the lower guard base portion 92B form a lower guard portion 90A that covers a grinding wheel 46 from below. In addition, the lower guard portion 90A is more durable than the clip portion 92A. This configuration makes the guard clip 90 have a structure where the lower guard portion 90A, which is subject to collisions with chips, sparks, and the like during grinding with the grinder 10, is less likely to be damaged. This enhances durability of the guard clip 90 compared to a configuration of omitting the protective cover 94 in the guard clip 90.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work machine. [Background technology]

[0002] In the angle grinder (working machine) described in Patent Document 1 below, a wheel guard (first cover) is provided on the head, and the wheel guard covers the grinding wheel from above and the sides. A cover (second cover) is also attached to the wheel guard. The cover has a seating surface that covers the side walls of the wheel guard and a protective disk that extends from the lower end of the seating surface, and the protective disk covers the grinding wheel from below. This allows the protective disk to prevent chips and sparks generated during machining from scattering below the grinding wheel. In other words, by attaching the cover to the wheel guard, the area that covers the grinding wheel is expanded by the cover.

[0003] The cover is fixed to the wheel guard by claw engagement. That is, the cover can be attached to the wheel guard without tools, making the cover more convenient. For this reason, the claws of the cover that engage with the wheel guard are elastically deformable. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2006 / 0068690 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned cover leaves room for improvement in the following respects. Specifically, if the cover is made of a resin material, for example, to allow the claws to be elastically deformed, the durability of the parts that come into contact with chips and sparks generated during machining may be insufficient. In this case, the cover mechanism consisting of the wheel guard and the cover may be compromised in its ability to cover the grinding wheel. This concern is particularly strong in angle grinders, which range in grinding wheel diameter from small to large, and which have high output during machining.

[0006] In consideration of the above, an object of the present invention is to provide a work machine that can suppress a decrease in the performance of covering a grinding wheel. [Means for solving the problem]

[0007] One or more embodiments of the present invention are a work machine having a motor, a housing that accommodates the motor, a spindle that extends in the vertical direction and rotates around an axis in the vertical direction by the driving force of the motor, a disc-shaped grinding wheel attached to the spindle so as to be rotatable integrally with it, a first cover that covers at least a portion of the upper surface and side surface of the grinding wheel, and a second cover that is detachably attached to the first cover, wherein the second cover includes a cover main body portion having an attachment portion that is attached to the first cover with elastic deformation, and a lower cover portion that is connected to the cover main body portion, covers the grinding wheel from below, and is configured to be more durable than the cover main body portion.

[0008] In one or more embodiments of the present invention, the lower cover portion is configured to include a protective portion made of an elastic material or a metal material.

[0009] One or more embodiments of the present invention are a work machine in which the lower cover portion has a base portion connected to the cover main body portion and the protective portion, the base portion being made of a resin material, and the protective portion being fixed to the base.

[0010] One or more embodiments of the present invention are directed to a work machine in which the protective portion is provided on the upper surface, the lower surface, or between the upper surface and the lower surface of the base.

[0011] In one or more embodiments of the present invention, the protective part is fixed to the top surface of the base by adhesive or screws.

[0012] One or more embodiments of the present invention are work implements in which the guard is integrally formed with the base.

[0013] One or more embodiments of the present invention are a work machine in which the cover main body and the base are constructed from a single member, and the protective portion is constructed from a separate member from the cover main body and the base.

[0014] In one or more embodiments of the present invention, the first cover is made of metal, and the side of the grinding wheel is covered by the first cover. [Effects of the Invention]

[0015] According to one or more embodiments of the present invention, it is possible to suppress a decrease in the performance of the cover for the grinding wheel. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a side view of a grinder according to an embodiment of the present invention, viewed from the left side. [Figure 2] 2 is a cross-sectional view showing the inside of the grinder shown in FIG. 1 as seen from the left side. [Figure 3] 3 is a perspective view of the guard mechanism shown in FIG. 2, seen from diagonally front left. [Figure 4] 4 is a perspective view showing a state in which the guard clip shown in FIG. 3 is removed from the wheel guard. FIG. [Figure 5] FIG. 10 is a perspective view showing a first modified example of the guard mechanism, as viewed obliquely from the rear right side. [Figure 6] FIG. 10 is a perspective view showing a second modified example of the guard mechanism, as viewed obliquely from the front left side. [Figure 7] 7 is a perspective view of the guard mechanism shown in FIG. 6, seen from the rear right side. [Figure 8] 4 is a perspective view showing an example in which the protective cover shown in FIG. 3 is integrally formed with the guard clip body. FIG. [Figure 9] 4 is a perspective view showing an example in which the protective cover shown in FIG. 3 is configured by a metal cover portion and an elastic cover portion. FIG. [Figure 10] 4 is a perspective view showing an example in which the protective cover shown in FIG. 3 is also provided on the underside of the upper clip portion of the guard clip body. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, a grinder 10 as a work machine according to this embodiment will be described with reference to the drawings. Note that arrows UP, FR, and LH, which are appropriately shown in the drawings, respectively indicate the upper side, front side, and left side of the grinder 10. In the following description, when the up-down, front-rear, and left-right directions are used, they refer to the up-down, front-rear, and left-right directions of the grinder 10 unless otherwise specified.

[0018] The grinder 10 is a power tool for performing grinding and other processes on a workpiece. As shown in Figures 1 and 2, the grinder 10 includes a housing 20, a motor 50, and a guard mechanism 70 (which may be broadly understood as a cover mechanism).

[0019] (About Housing 20) The housing 20 forms the outer shell of the grinder 10. The housing 20 is formed as a hollow column extending in the front-to-rear direction as a whole. The housing 20 includes a tail cover 22 that forms the rear end of the housing 20, a motor housing 24 disposed in front of the tail cover 22, and a gear housing 26 disposed in front of the motor housing 24.

[0020] The tail cover 22 is formed in a generally cylindrical shape with a bottom that is open to the front. A power cord 34 is provided at the rear end of the tail cover 22 and extends rearward from the tail cover 22. The power cord 34 supplies external commercial power to a motor 50, which will be described later. A switch 30 is housed in the tail cover 22, and the switch 30 is held in a switch holder 36 fixed to the tail cover 22.

[0021] The motor housing 24 is formed in a generally cylindrical shape with its axial direction extending in the front-to-rear direction, and is fixed at a position not shown to the tail cover 22. A fan accommodating section 24A is formed at the front end of the motor housing 24, protruding radially outward, and the fan accommodating section 24A is formed in a generally rectangular shape when viewed from the front.

[0022] A switch lever 32 (see FIG. 1) is provided on the left side of the motor housing 24. The switch lever 32 is connected to the motor housing 24 so as to be slidable in the front-to-rear direction. Specifically, the switch lever 32 is disposed in the OFF position shown in FIG. 1, and is configured to slide forward from the OFF position when operated by an operator. A slide bar (not shown) is connected to the switch lever 32, and the slide bar is disposed within the motor housing 24 and the tail cover 22 and is configured to be slidable in the front-to-rear direction. When the switch lever 32 slides from the OFF position to the ON position, the slide bar switches the switch 30 from OFF to ON.

[0023] The gear housing 26 is hollow and generally triangular when viewed from the left and right, and is open downward. A connected portion 26A is formed at the rear end of the gear housing 26, and the connected portion 26A is formed in a generally rectangular tubular shape corresponding to the fan accommodating portion 24A of the motor housing 24. The fan accommodating portion 24A and the connected portion 26A are abutted against each other in the front-to-rear direction, and the connected portion 26A is fastened and fixed to the fan accommodating portion 24A. A packing gland 28 is provided on the lower side of the gear housing 26. The packing gland 28 is formed in a stepped cylindrical shape with its axial direction extending vertically, and is fixed to the gear housing 26.

[0024] A spindle 40 is provided within the gear housing 26 and is formed in a generally cylindrical shape with its axial direction extending vertically. The upper end of the spindle 40 is rotatably supported by a bearing 42 fixed to the gear housing 26, and the vertical middle portion of the spindle 40 is rotatably supported by a bearing 44 fixed to the packing gland 28. A grinding stone 46 is attached to the lower end (one axial end) of the spindle 40. The grinding stone 46 is formed in a generally circular plate shape with its thickness direction extending vertically, and the axial center of the grinding stone 46 is attached to the spindle 40. The grinding stone 46 rotates together with the spindle 40 by the driving force of a motor 50 (described later), thereby performing grinding or other processes on the workpiece.

[0025] (Regarding motor 50) The motor 50 is housed in the motor housing 24. The motor 50 has a rotary shaft 50A whose axial direction is the front-to-rear direction. The rear end of the rotary shaft 50A is rotatably supported by a first motor bearing 52 fixed to the switch holder 36, and the front end of the rotary shaft 50A is rotatably supported by a second motor bearing 54 fixed to the gear housing 26. The front end of the rotary shaft 50A is disposed within the gear housing 26, and a pinion gear 56 is fixed to the front end of the rotary shaft 50A on the front side of the second motor bearing 54. The pinion gear 56 meshes with a bevel gear 58 provided on the upper part of the spindle 40, and the driving force of the motor 50 is transmitted to the spindle 40 via the bevel gear 58. The motor 50 is electrically connected to the switch 30. When the switch 30 is turned on, the motor 50 is driven. A fan 60 is provided on the front end of the rotary shaft 50A behind the second motor bearing 54 so as to be rotatable integrally therewith, and the fan 60 is disposed within the fan housing portion 24A.

[0026] (Regarding the guard mechanism 70) The guard mechanism 70 is a mechanism that covers the rear portion of the grinding wheel 46. As shown in Figs. 1 to 4, the guard mechanism 70 includes a wheel guard 80 as a first cover and a guard clip 90 as a second cover. Below, the wheel guard 80 will be described first, and then the guard clip 90 will be described.

[0027] (About Wheel Guard 80) The wheel guard 80 is made of metal. The wheel guard 80 has a clamp member 82 and a clamp lever 84, and the wheel guard 80 is attached to the packing land 28 by the clamp member 82 and the clamp lever 84. The wheel guard 80 is formed in a generally semi-cylindrical shape with a bottom that is open downward and forward. Specifically, the wheel guard 80 includes a generally semi-circular upper guard wall 80A with a thickness in the up-down direction, and a side guard wall 80B extending downward from the outer periphery of the upper guard wall 80A. An attachment piece 80C bent upward at the center in the left-right direction is formed at the front end of the upper guard wall 80A. The attachment piece 80C is curved in a generally semi-circular shape that is open forward in a plan view, and both left and right ends of the attachment piece 80C are bent outward in the left-right direction. The attachment piece 80C is disposed behind the lower end of the packing land 28.

[0028] The clamp member 82 is disposed in front of the lower end of the packing land 28 and is curved in a generally arcuate shape along the circumferential direction of the packing land 28. The left end of the clamp member 82 is connected to the mounting piece 80C by a fixing screw 86 that is threaded into the left end of the mounting piece 80C. The right end of the clamp member 82 is disposed opposite the right end of the mounting piece 80C in the front-to-rear direction. The clamp lever 84 is disposed in front of the clamp member 82 and extends in the left-to-right direction. The right end of the clamp lever 84 is rotatably connected to the wheel guard 80 with the up-to-down direction as the axial direction. When the clamp lever 84 is tilted along the clamp member 82, the right end of the clamp lever 84 pushes the right end of the clamp member 82 rearward, so that the clamp member 82 and the mounting piece 80C clamp the lower end of the packing land 28 from both the front-to-rear direction. In this way, the wheel guard 80 is attached to the packing land 28.

[0029] When the wheel guard 80 is attached, the upper guard wall 80A is disposed above the grinding wheel 46, and the side guard wall 80B is disposed radially outward of the grinding wheel 46. The lower end of the side guard wall 80B is located below the grinding wheel 46, and an inclined portion 80D is formed at the lower end of the side guard wall 80B, inclining radially inward as it extends downward. As a result, the wheel guard 80 mainly covers the rear portion of the grinding wheel 46 from above and from the radially outer side (side). The position of the wheel guard 80 in the circumferential direction of the spindle 40 can be changed by an operator by rotating the clamp lever 84 to release the clamping by the clamp member 82.

[0030] (About Guard Clip 90) The guard clip 90 is detachably attached to the wheel guard 80 and is configured as a cover that covers the grinding wheel 46 from below. In other words, by attaching the guard clip 90 to the wheel guard 80, the range that covers the grinding wheel 46 is expanded by the guard clip 90.

[0031] The guard clip 90 includes a guard clip main body 92 and a protective cover 94 as a protective portion provided on the guard clip main body 92. The guard clip main body 92 is made of resin. The guard clip main body 92 includes a clip portion 92A as a cover main body portion attached to the wheel guard 80, and a lower guard base portion 92B as a base portion.

[0032] The clip portion 92A is formed in a generally bottomed semi-cylindrical shape that is open downward and forward in correspondence with the wheel guard 80, and is attached to the wheel guard 80 so as to cover the wheel guard 80 from above and from the radially outer side. Specifically, the clip portion 92A is configured to include an upper clip portion 92A-1 (broadly understood as an element that can be understood as an upper wall) that forms the upper end of the guard clip 90, and a side clip portion 92A-2 (broadly understood as an element that can be understood as a side wall) that extends downward from the upper clip portion 92A-1.

[0033] The upper clip portion 92A-1 is formed in a generally arc-shaped plate shape with its thickness extending in the vertical direction and open to the front. The upper clip portion 92A-1 is disposed adjacent to the upper side of the wheel guard 80 so as to cover the entire outer periphery of the upper guard wall 80A of the wheel guard 80 from above. Both longitudinal ends of the upper clip portion 92A-1 protrude forward beyond the upper guard wall 80A of the wheel guard 80.

[0034] The side clip portion 92A-2 extends downward from the outer periphery of the upper clip portion 92A-1 and is disposed radially outward of the side guard wall 80B of the wheel guard 80. An inclined portion 92C is formed at the lower end of the side clip portion 92A-2, corresponding to the inclined portion 80D of the wheel guard 80. The inclined portion 92C inclines radially inward as it extends downward, and is disposed adjacent to the lower side of the inclined portion 80D of the wheel guard 80. As a result, the inclined portion 92C of the side clip portion 92A-2 and the upper clip portion 92A-1 sandwich the wheel guard 80 in the vertical direction, thereby determining the vertical position of the guard clip main body 92.

[0035] The inner peripheral surface of the side clip portion 92A-2 is formed with a plurality of (three in this embodiment) abutment portions 92D in a vertically intermediate portion. When viewed from the radial direction of the side clip portion 92A-2, the abutment portions 92D are formed in a substantially rectangular shape and protrude radially inward from the inner peripheral surface of the side clip portion 92A-2. Two abutment portions 92D are provided at both circumferential ends of the side clip portion 92A-2, and one abutment portion 92D is provided in a circumferentially intermediate portion of the side clip portion 92A-2. The abutment portions 92D are disposed adjacent to the radially outer side of the side guard wall 80B of the wheel guard 80.

[0036] The lower guard base 92B is formed in a generally arc-shaped plate shape with its thickness extending vertically, and extends radially inward from the lower end of the inclined portion 92C of the side clip portion 92A-2. The lower guard base 92B is disposed below the grindstone 46 and covers the rear of the grindstone 46 from below. The front end of the lower guard base 92B protrudes further forward than the front end of the wheel guard 80.

[0037] At the upper end of each circumferential end of the side clip portion 92A-2, a slit 92E is formed penetrating in the left-right direction. The slit 92E is formed as a groove extending in the circumferential direction of the side clip portion 92A-2, with the front end of the slit 92E open to the front. A portion of the front end of the upper clip portion 92A-1 adjacent to the slit 92E forms an engagement claw 92F as an attachment portion, and the engagement claw 92F is configured to be elastically deformable in the up-down direction. That is, a pair of left and right engagement claws 92F is formed at the front end of the upper clip portion 92A-1. A hook portion 92G protruding downward is formed at the front end of the engagement claw 92F, and the hook portion 92G is formed in a generally rib-like shape extending in the left-right direction. The hook portion 92G is disposed adjacent to the front side of the upper guard wall 80A of the wheel guard 80 and engages with the upper guard wall 80A in the front-rear direction. This limits rearward movement of the guard clip body 92 relative to the wheel guard 80.

[0038] When attaching the guard clip body 92 to the wheel guard 80, the guard clip body 92 is positioned behind the wheel guard 80 (see FIG. 4). The guard clip body 92 is moved forward to insert the wheel guard 80 into the guard clip body 92, thereby attaching the guard clip body 92 to the wheel guard 80. At this time, the engaging claw portion 92F elastically deforms upward, allowing the wheel guard 80 to be inserted into the guard clip body 92. When the attachment of the guard clip body 92 to the wheel guard 80 is complete, the engaging claw portion 92F elastically deforms downward, and the hook portion 92G engages with the upper guard wall 80A of the wheel guard 80 in the front-rear direction.

[0039] The protective cover 94 is provided on the upper surface of the lower guard base 92B (in Figures 3 and 4, the upper surface of the protective cover 94 is hatched to make it easier to understand). Therefore, the lower end of the guard clip 90 is a lower guard part 90A that serves as a lower cover part composed of the lower guard base 92B of the guard clip body 92 and the protective cover 94. In other words, the guard clip 90 is composed of the clip part 92A that is detachably attached to the wheel guard 80 and the lower guard part 90A that has the protective cover 94 connected to the clip part 92A, and the grinding wheel 46 is covered from below by the lower guard part 90A.

[0040] The protective cover 94 is made of an elastic material such as rubber or elastomer and is formed into a sheet shape with its thickness extending vertically. The outer shape of the protective cover 94 substantially matches the outer shape of the lower guard base 92B, and the protective cover 94 is attached to the upper surface of the lower guard base 92B with an adhesive or the like. This covers the upper surface of the lower guard base 92B. As described above, the lower guard portion 90A includes the lower guard base 92B and the protective cover 94 made of an elastic material, and the protective cover 94 covers the lower guard base 92B. Therefore, the lower guard portion 90A is less likely to deform or break when subjected to a load such as an impact load, compared to the clip portion 92A, which does not have the protective cover 94. In other words, in the guard clip 90, the lower guard portion 90A is more durable than the clip portion 92A. The guard clip 90 is also designed with a protective cover 94 to prevent chips, sparks, and the like from directly hitting the lower guard base 92B during grinding and other processes. While the thickness of the protective cover 94 is not specifically defined, the thickness of the protective cover 94 can be appropriately adjusted, for example, to absorb the impact of chips and the like. In the present invention, durability refers to the degree to which the area covered by the lower guard portion 90A on the underside of the protective cover 94 is maintained even when subjected to a load such as an impact load. If the coverage area easily changes due to the load, durability is considered low. Conversely, if the coverage area does not change even when an excessive load is applied, durability is considered high. Specifically, durability is considered low if the edge of the lower guard portion 90A is easily chipped by flying chips during processing or if holes are easily created in the lower guard portion 90A by sparks and the like. In other words, durability refers to the resistance to deformation due to external loads such as impact resistance and heat resistance, but in the case of the present invention, high durability is achieved if the coverage area can be maintained even if scratches are caused to the surface of the lower guard portion 90A, etc.

[0041] (Action and effect) Next, the operation and effects of the grinder 10 of this embodiment will be described.

[0042] When using the grinder 10 for grinding, the operator slides the switch lever 32 forward from the OFF position, switching the switch 30 from OFF to ON and driving the motor 50. This causes the grinding wheel 46 to rotate together with the spindle 40, allowing the grinding wheel 46 to perform grinding or other processing on the workpiece. The grinder 10 also has a guard mechanism 70, which uses a wheel guard 80 to cover the rear of the grinding wheel 46 from above and radially outward. This prevents chips, sparks, and other particles generated during grinding or other processing with the grinder 10 from scattering above and behind the grinding wheel 46. The guard mechanism 70 also has a guard clip 90 attached to the wheel guard 80, which covers the grinding wheel 46 from below with a lower guard portion 90A of the guard clip 90. This prevents chips, sparks, and other particles generated during grinding or other processing with the grinder 10 from scattering below the grinding wheel 46.

[0043] The guard clip 90 includes a guard clip main body 92 and a protective cover 94. The guard clip main body 92 has a clip portion 92A attached to the wheel guard 80 and a lower guard base portion 92B connected to the clip portion 92A. A protective cover 94 made of an elastic material covers the upper surface of the lower guard base portion 92B, and the protective cover 94 and the lower guard base portion 92B form a lower guard portion 90A that covers the grinding wheel 46 from below. The lower guard portion 90A is more durable than the clip portion 92A. This structure makes the lower guard portion 90A, which is subject to collision with chips, sparks, and the like during grinding with the grinder 10, less susceptible to damage. This improves the durability of the guard clip 90 compared to a guard clip 90 that does not include the protective cover 94. This prevents a decrease in the ability of the guard mechanism 70 to cover the grinding wheel 46.

[0044] In particular, in this embodiment, the protective cover 94 effectively improves the durability of the resin guard clip body 92. Specifically, the guard clip body 92 is made of resin to allow the engaging claws 92F to be elastically deformable. Furthermore, the guard clip body 92 is formed with slits 92E for forming the engaging claws 92F. Therefore, when a downward impact load is applied to the lower guard portion 90A from chips or the like during a polishing process, stress corresponding to the impact load tends to concentrate at the ends of the slits 92E. In contrast, by configuring the lower guard portion 90A to include the protective cover 94, the protective cover 94 can receive chips or the like generated during a polishing process and absorb the impact load applied to the guard clip body 92. This reduces stress concentration in the slits 92E of the guard clip body 92. Therefore, the durability of the guard clip 90 can be improved while preventing damage to the guard clip body 92.

[0045] Furthermore, by covering the upper surface of the lower guard base 92B with the protective cover 94, it is possible to prevent chips, sparks, and the like generated during grinding by the grinder 10 from directly hitting the lower guard base 92B. This allows the lower guard base 92B to be protected by the protective cover 94. From this perspective, damage to the lower guard base 92B is suppressed and the durability of the guard clip 90 can be improved compared to a configuration in which the protective cover 94 is omitted from the guard clip 90.

[0046] The protective cover 94 is made of an elastic material such as rubber. This allows the elastic body to absorb the impact of the load and increase durability. The elastic body may also be highly fire-resistant, in which case thermal deformation of the lower guard part 90A can be suppressed. Furthermore, because the protective cover 94 is fixed with an adhesive, the lower guard part 90A can be easily constructed using a variety of elastic bodies.

[0047] In addition, the guard clip body 92 is made of resin. Therefore, compared to a guard clip body 92 made of metal, the guard clip body 92 can be made lighter, and the weight of the front end portion of the grinder 10 can be reduced.

[0048] The wheel guard 80 is made of metal and covers the grinding wheel 46 from above and from the sides. This allows the metal wheel guard 80 to catch sparks that are scattered in a concentrated manner on the sides of the grinding wheel 46. Therefore, the wheel guard 80 can protect the clip portion 92A of the guard clip 90.

[0049] (Modification 1 of guard clip 90) Next, a first modified example of the guard clip 90 will be described with reference to Fig. 5. The first modified example of the guard clip 90 is configured similarly to the guard clip 90 of the present embodiment, except for the following points. In Fig. 5, the same reference numerals are used to designate parts that are configured similarly to the present embodiment.

[0050] That is, as shown in this figure, in Modification 1 of the guard clip 90, the guard clip main body 92 is composed of guard clip members 93L and 93R that are divided into two in the left-right direction. In addition, in accordance with the division of the guard clip main body 92 into two, the protective cover 94 (not shown in FIG. 5) is also divided into two in the left-right direction and is attached to the lower guard base portions 92B of the guard clip members 93L and 93R.

[0051] A connecting mechanism 100 for connecting the guard clip members 93L, 93R is provided at the rear end portions of the guard clip members 93L, 93R. The connecting mechanism 100 is configured as a so-called snap lock. Specifically, the connecting mechanism 100 includes a lever 101 rotatably provided on the guard clip member 93L and a latch portion 102 provided on the guard clip member 93R. By engaging a hook 103 provided on the lever 101 with a latch groove of the latch portion 102 and tilting the lever 101, the guard clip members 93L, 93R are pulled inward in the left-right direction and connected to each other.

[0052] In the first modification of the guard clip 90, as described above, the guard clip body 92 is divided into two parts in the left-right direction. Therefore, when the guard clip 90 is not in use in the guard mechanism 70, the divided guard clip 90 can be put together compactly. This, for example, can improve the storage performance of the guard clip 90 when it is not in use.

[0053] (Modification 2 of guard clip 90) Next, a second modification of the guard clip 90 will be described with reference to Figures 6 and 7. The second modification of the guard clip 90 is configured similarly to the guard clip 90 of the present embodiment, except for the following points. In Figures 6 and 7, the same reference numerals are used to designate parts that are configured similarly to the present embodiment.

[0054] That is, as shown in these figures, in the second modified example of the guard clip 90, the upper clip portion 92A-1 is omitted and the upper end portion of the side clip portion 92A-2 is cut out in the clip portion 92A of the guard clip main body 92. That is, in the second modified example of the guard clip 90, the guard clip main body 92 covers only the portion of the side guard wall 80B of the wheel guard 80 excluding the upper end portion from the radial outside.

[0055] A slit 92H is formed in the front end of the side clip portion 92A-2 at a vertically intermediate portion thereof, penetrating the left-right direction. The slit 92H is formed as a groove extending circumferentially of the side clip portion 92A-2, and the front end of the slit 92H is open. The portion of the front end of the side clip portion 92A-2 above the slit 92H serves as an engagement claw portion 92J, which is configured to be elastically deformable in the left-right direction. A hook portion 92K protruding inward in the left-right direction is provided at the front end of the right engagement claw portion 92J. The hook portion 92K is positioned adjacent to the front side of the front end of the side guard wall 80B of the wheel guard 80 and engages with the wheel guard 80 in the front-rear direction. This restricts rearward movement of the guard clip 90.

[0056] In addition, a plurality of (five in this embodiment) fixing protrusions 92L are provided on the outer periphery of the upper surface of the lower guard base 92B, and the fixing protrusions 92L are arranged at equal intervals in the circumferential direction of the lower guard base 92B. The fixing protrusions 92L and the side clip portion 92A-2 clamp the side guard wall 80B of the wheel guard 80 in the radial direction.

[0057] The wheel guard 80 and the guard clip 90 are provided with a pair of left and right connecting mechanisms 110 for connecting the two together. The connecting mechanism 110 is configured as a so-called snap lock, similar to the connecting mechanism 100 of Modification 1. Specifically, the connecting mechanism 110 includes a lever 111 rotatably provided on the side clip portion 92A-2 of the guard clip main body 92, and a latch portion 112 provided on the side guard wall 80B of the wheel guard 80. By engaging a hook 113 provided on the lever 111 with a latch groove of the latch portion 112 and tilting the lever 111, the guard clip 90 is pulled upward and connected to the wheel guard 80.

[0058] In the guard clip 90 of the second modification, as described above, the upper clip portion 92A-1 is omitted from the clip portion 92A, and the upper end portion of the side clip portion 92A-2 is cut out. This allows the guard clip 90 to be made smaller in size in the vertical direction. This, for example, improves the storage performance of the guard clip 90 when not in use.

[0059] In the present embodiment (including Modifications 1 and 2), the protective cover 94 is attached to the upper surface of the lower guard base 92B with an adhesive, but the method for fixing the protective cover 94 is not limited to this. For example, as shown in Fig. 8, the protective cover 94 may be formed integrally with the lower guard base 92B by a technique such as two-color molding (integral molding). Also, the protective cover 94 may be fixed to the lower guard base 92B using fixing members such as screws.

[0060] Furthermore, in the present embodiment (including Modifications 1 and 2), the protective cover 94 of the guard clip 90 is made of an elastic material such as rubber. However, the protective cover 94 may be made of a metal plate. Even in this case, the lower guard portion 90A can be designed to be less susceptible to damage when subjected to an impact load, making it more durable than the clip portion 92A. This reduces damage to the lower guard portion 90A, which may be struck by chips or other debris during polishing or other processes, thereby improving the durability of the guard clip 90. Furthermore, the metallic protective cover 94 effectively protects the lower guard base 92B by catching sparks generated during polishing or other processes. Furthermore, when the protective cover 94 is made of a metal plate, the protective cover 94 and the guard clip 90 may be integrally formed by insert molding or other techniques. Furthermore, when the protective cover 94 is made of a metal plate, the protective cover 94 may be embedded within the lower guard base 92B.

[0061] As shown in FIG. 9, the protective cover 94 may be composed of a metal cover portion 94A made of a metal material and an elastic cover portion 94B made of an elastic material, with the metal cover portion 94A and the elastic cover portion 94B stacked in the thickness direction. In the example shown in FIG. 9, the protective cover 94 is composed of two elastic cover portions 94B and one metal cover portion 94A, with the metal cover portion 94A sandwiched between the two elastic cover portions 94B from both sides in the vertical direction. This increases the strength and durability of the lower guard portion 90A in the guard clip 90 including the protective cover 94. Alternatively, the protective cover 94 may be composed of two metal cover portions 94A and one elastic cover portion 94B, which effectively prevents scratches on the surface of the elastic cover portion 94B.

[0062] Furthermore, in the present embodiment (including Modifications 1 and 2), the protective cover 94 covers the upper surface of the lower guard base 92B. However, it may also be configured to cover the lower surface of the lower guard base 92B. In this case, the protective cover 94 protects the lower surface of the lower guard base 92B. This allows the protective cover 94 to absorb external forces applied to the lower guard portion 90A from below. Furthermore, as shown in FIG. 10 , the protective cover 94 may also be provided on the lower surface of the upper clip portion 92A-1. In the above configuration, the lower guard portion 90A is formed by attaching the protective cover 94, which is made of a material that tends to be more durable than resin, to the lower guard base 92B, which is made of resin. However, the present invention is not limited to such a combination of different materials. For example, the lower guard base 92B may be provided with a concave-convex shape so that the convex portions are actively crushed upon receiving a high impact. This may allow the lower guard portion 90A to withstand multiple impacts and prevent the coverage area from changing. This configuration reduces the number of parts, resulting in excellent cost performance. Furthermore, the clip portion 92A and the lower guard base portion 92B may be made of metal so as to be deformable, and the protective cover 94 made of an elastic material may be attached.

[0063] Furthermore, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0064] 10 Grinder (working machine) 20. Housing 40 spindles 46 Whetstone 50 motor 80 Wheel guard (first cover) 90 Guard clip (second cover) 90A Lower guard part (lower cover part) 92A Clip part (cover body) 92B Lower Guard Base (Base) 92F Engagement claw part (mounting part) 94 Protective cover (protective part)

Claims

1. A motor; a housing that accommodates the motor; a spindle extending in a vertical direction and rotating about an axis in the vertical direction by the driving force of the motor; a disc-shaped grinding wheel attached to the spindle so as to be integrally rotatable; a first cover that covers at least a portion of the top surface and side surface of the grindstone; a second cover detachably attached to the first cover; and The second cover is a cover body having an attachment portion that is attached to the first cover while undergoing elastic deformation; a lower cover portion connected to the cover main body portion, covering the grindstone from below, and having higher durability than the cover main body portion; A work machine comprising:

2. 2. The work machine according to claim 1, wherein the lower cover portion includes a protective portion made of an elastic material or a metal material.

3. The lower cover portion is a base connected to the cover body; The protective portion; It has The work machine according to claim 2, wherein the base is made of a resin material, and the protection part is fixed to the base.

4. The work machine according to claim 3, wherein the protective portion is provided on one of the upper surface, the lower surface, and a portion between the upper surface and the lower surface of the base.

5. The work machine according to claim 4 , wherein the protection portion is fixed to the upper surface of the base by adhesive or screws.

6. The work machine according to claim 3 , wherein the protection portion is integrally formed with the base portion.

7. 4. The work machine according to claim 3, wherein the cover body and the base are formed from a single member, and the protection portion is formed from a separate member from the cover body and the base.

8. 2. The work machine according to claim 1, wherein the first cover is made of metal, and the side of the grinding wheel is covered by the first cover.

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