Abrasive disc, abrasive unit and abrasive device

Abstract

To provide a polishing disc, polishing unit and polishing device that can achieve a reduction in the wear of a fastener.SOLUTION: A polishing disc 10 is formed from a flexible substrate 1 of a disk shape and has one face to be a polishing face 2 having an abrasive 2a stuck thereto. A fitting hole 3 is provided in the center. Around the fitting hole 3 on the polishing face 2 side, a coating layer 4 with a smooth surface is provided in a circle.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a polishing disk, a polishing unit and a polishing apparatus for polishing an object to be polished. [Background technology]

[0002] Hand grinders, for example, are widely used as tools for polishing or grinding objects to be polished or ground (hereinafter also referred to as "workpieces"). A polishing or grinding tool made of a rotating grindstone, abrasive cloth, or the like is attached to the rotating shaft of the hand grinder, and the surface of the workpiece can be polished or ground by pressing the attached polishing or grinding tool against the workpiece while rotating.

[0003] For example, Patent Document 1 discloses a portable grinder in which a circular abrasive disk and pad are attached to a rotating shaft. The abrasive disk and pad are inserted into a shaft extending from the main body of the portable grinder, and the abrasive disk and pad are fixed to the shaft by tightening a female-threaded nut onto the male-threaded shaft. The nut functions as a fastener for clamping the abrasive disk and pad between the nut and a boss portion at the base of the shaft. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-200883 A Summary of the Invention [Problem to be solved by the invention]

[0005] The portable grinder of Patent Document 1 is a type of grinder that is attached by sandwiching an abrasive unit consisting of an abrasive disk and a pad, and a nut is used as a fastener for sandwiching the abrasive unit. The flange part of the nut is in contact with the abrasive surface of the abrasive disk. In this type of conventional grinder, if the nut is repeatedly tightened every time the abrasive disk is replaced, the flange part of the nut that contacts the abrasive surface will wear out. As the wear of the flange part of the nut that contacts the abrasive surface progresses, the clamping of the abrasive unit will no longer work, and the function of the nut as a fastener will be lost. When the function of the nut as a fastener is lost, even if the abrasive disk is pressed against the workpiece, the shaft will rotate freely relative to the abrasive disk, and no abrasive force will be exerted. For this reason, there is a demand to provide an abrasive disk that reduces the wear of the fastener due to contact with the abrasive disk.

[0006] The present invention provides an abrasive disc, abrasive unit and abrasive apparatus that reduces fastener wear. [Means for solving the problem]

[0007] The abrasive disc of the present invention is formed from a disc-shaped flexible substrate and has an abrasive surface on one side with an abrasive material adhered to it, with a mounting hole in the center and a smooth-surfaced coating layer provided in a ring shape around the mounting hole on the abrasive surface side.

[0008] According to the abrasive disc of the present invention, a coating layer with a smooth surface is provided in an annular shape around the mounting hole on the abrasive surface side. This coating layer has a function of preventing the metal fittings for mounting the abrasive disc to the drive device from wearing out due to the tightening operation, and the wear of the fasteners that progresses every time the abrasive disc is replaced is reduced.

[0009] Preferably, the coating layer is provided in areas that will contact fasteners for attaching the abrasive disc to a drive device.

[0010] Preferably, the abrasive surface has a recess in the area around the mounting hole, whereby a fastener for mounting the abrasive disc to the drive device can clamp the abrasive disc between the drive device and the abrasive disc without protruding from the abrasive surface, and interference between the workpiece and the fastener when the abrasive disc is pressed against the workpiece can be reduced.

[0011] Preferably, the covering layer is formed by attaching a washer to the peripheral edge of the mounting hole.

[0012] Preferably, the abrasive disc further includes a plurality of slits extending radially from the periphery of the mounting hole.

[0013] The polishing unit of the present invention comprises a combination of the polishing disc of the present invention and a pressure pad that is placed on the side of the polishing disc opposite the polishing surface, the pressure pad having a through hole in the center that communicates with the mounting hole of the polishing disc when the pressure pad is placed on the polishing disc, and the surface that is placed on the polishing disc is formed into a pressing surface having irregularities.

[0014] Preferably, the pressing surface is configured with a plurality of ridges extending radially from a central portion to an outer periphery and grooves between the plurality of ridges.

[0015] The polishing device according to the present invention comprises a polishing unit according to the present invention, a drive unit having a rotating shaft protruding outside the machine, a lower fastener having an engagement portion that engages with the rotating shaft so as to rotate integrally with the rotating shaft, and an upper fastener that clamps the polishing unit between the lower fastener. The lower fastener integrally has a cylindrical portion through which the rotating shaft is inserted and causes the tip of the rotating shaft to protrude, and an annular support surface that goes around the outer periphery of the cylindrical portion and supports the center of the lower surface of the pressure pad, and the upper fastener integrally has a boss portion that passes through the mounting hole of the abrasive disc, and a flange portion that is pressed against the coating layer of the abrasive disc and clamps the polishing unit between the annular support surface of the lower fastener, and a thread is formed on the inner surface of the boss portion to be screwed onto the thread of the rotating shaft. Effect of the Invention

[0016] According to the present invention, it is possible to provide an abrasive disc, an abrasive unit, and an abrasive device that reduce wear on fasteners. [Brief description of the drawings]

[0017] [Figure 1] 1A to 1C are a plan view, a side view, and a bottom view showing the configuration of an abrasive disc according to one embodiment of the present invention. [Diagram 2] 1 is an exploded perspective view of a polishing apparatus according to an embodiment of the present invention; [Diagram 3] 1 is an exploded perspective view of a polishing apparatus according to an embodiment of the present invention; [Figure 4] 4 is an exploded perspective view for explaining an attachment state of a lower fastener provided in the polishing apparatus according to the embodiment of the present invention. FIG. [Diagram 5] 1 is a cross-sectional view and a partially enlarged cross-sectional view of a polishing apparatus according to an embodiment of the present invention; [Figure 6] 1 is a perspective view for explaining a manufacturing procedure of an abrasive disc according to one embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description and drawings, the same reference numerals denote the same or similar components, and therefore, redundant description of the same or similar components will be omitted.

[0019] In this specification, the term "polishing" is a concept that includes grinding, and the term "grinding" is a concept that includes polishing. [Polishing disc]

[0020] 1 is a diagram showing the configuration of an abrasive disc 10 according to one embodiment of the present invention, in which (A) is a plan view of the abrasive disc, (B) is a side view of the abrasive disc, and (C) is a bottom view of the abrasive disc.

[0021] An abrasive disc 10 according to one embodiment of the present invention is an abrasive tool that is attached to a rotating shaft of a hand grinder or the like. As shown in (A), the abrasive disc 10 is formed of a disk-shaped flexible substrate 1, and one surface of the flexible substrate 1 is provided with an abrasive surface 2 to which an abrasive material 2a is fixed. A mounting hole 3 is provided in the center of the abrasive disc 10, and a coating layer 4 with a smooth surface is provided in an annular shape around the mounting hole 3 on the side of the abrasive surface 2.

[0022] For example, craft paper, vulcanized fiber, polyethylene terephthalate (PET), nonwoven fabric, cotton cloth, synthetic cloth, etc. can be used for the flexible substrate 1. Abrasive material 2a such as silicon carbide or diamond is fixed to the polishing surface 2 by, for example, an adhesive. For example, various types of coated abrasive paper can be used for the flexible substrate 1 provided with such a polishing surface 2.

[0023] A rotating shaft 61 of a driving device 60 such as a hand grinder is inserted into the mounting hole 3. The polishing unit 30 including the polishing disc 10 and the pressing pad 20, and the state in which the polishing unit 30 is mounted on the driving device 60 having the rotating shaft 61 will be described later with reference to FIG.

[0024] The coating layer 4 is provided in an area that contacts a fastener (an upper fastener 50 described later, hereinafter also simply referred to as a "fastener") for attaching the abrasive disc 10 to the drive unit 60. In this embodiment, the coating layer 4 is formed by crimping a washer to the hole periphery of the mounting hole 3, thereby reducing wear of the fastener 50 that may progress every time the abrasive disc 10 is replaced. The fastener 50 is for attaching the abrasive disc 10 to the drive unit 60, and in this embodiment, it is the upper fastener 50, and a flange portion 52 of the upper fastener 50 contacts the smooth surface 4a of the coating layer 4. Wear of the upper fastener 50 will be described later with reference to FIG. 5. As shown in (C), the crimped washer protrudes from the mounting hole 3 on the surface opposite to the grinding surface 2 and is folded back outward. In the figure, the symbol 4b indicates the folded back portion. Exemplarily, the material of the washer is a metal such as aluminum. The thickness D of the surface 4a of the coating layer 4 that comes into contact with a flange portion 52 of the upper fastener 50 shown in FIG. 5, which will be described later, is illustratively about 0.5 mm to about 1 mm.

[0025] As shown in (B), in this embodiment, the polishing surface 2 is recessed in the area around the mounting hole 3. This allows the fastener 50 for mounting the polishing disc 10 to the driving device 60 to clamp the polishing unit 30 between itself and the driving device 60 without protruding from the polishing surface 2, thereby reducing interference between the workpiece and the fastener 50 when the polishing disc 10 is pressed against the workpiece.

[0026] In this embodiment, the abrasive disc 10 is provided with a plurality of slits 5 extending radially from the periphery of the mounting hole 3. By providing a plurality of slits 5 in the abrasive disc 10, it is possible to reduce cracks in the abrasive disc 10 that occur during press processing when manufacturing the abrasive disc 10. [Polishing unit and polishing device]

[0027] Fig. 2 and Fig. 3 are exploded perspective views of a polishing apparatus 100 according to one embodiment of the present invention. Fig. 2 is an exploded perspective view of the polishing unit 30 as viewed from the polishing disc 10 side, and Fig. 3 is an exploded perspective view of the polishing unit 30 as viewed from the pressure pad 20 side. Fig. 4 is an exploded perspective view for explaining the attachment state of a lower fastener 40 provided in the polishing apparatus 100.

[0028] The polishing device 100 according to one embodiment of the present invention includes a polishing unit 30 consisting of a combination of a polishing disc 10 and a pressure pad 20, a lower fastener 40 and an upper fastener 50 for clamping the polishing unit 30, and a drive device 60 having a rotating shaft 61 protruding outside the machine. The polishing unit 30 is attached to the rotating shaft 61 of the drive device 60, and the polishing disc 10 of the polishing unit 30 is pressed against a workpiece while being rotated, thereby polishing the surface of the workpiece. Illustratively, the polishing device 100 is a hand grinder, and the drive device 60 is a main body of the hand grinder.

[0029] A polishing unit 30 according to one embodiment of the present invention is composed of a combination of a polishing disc 10 and a pressure pad 20 that is placed on the surface of the polishing disc 10 opposite to the polishing surface 2.

[0030] The pressure pad 20 has a through hole 21 in the center that communicates with the mounting hole 3 of the abrasive disc 10 when the pressure pad 20 is placed on the abrasive disc 10. The pressure pad 20 is disk-shaped, and the surface of the pressure pad 20 that is placed on the abrasive disc 10 is formed into a pressing surface 22 having irregularities. The pressing surface 22 of the pressure pad 20 presses the abrasive disc 10 from the surface opposite the abrasive surface 2 of the abrasive disc 10, whereby the abrasive disc 10 of the polishing unit 30 exerts a polishing force. Illustratively, the pressure pad 20 is made of synthetic resin.

[0031] In this embodiment, the pressing surface 22 is composed of a plurality of ridges 22a extending radially from the center to the outer periphery, and recessed grooves 22b between the plurality of ridges 22a. In this embodiment, the pressing pad 20 has a plurality of through holes 23 arranged circumferentially around the through hole 21 arranged at the center.

[0032] The lower fastener 40 is disposed on the pressing pad 20 side of the polishing unit 30, and clamps the polishing unit 30 between the lower fastener 40 and the upper fastener 50. The lower fastener 40 has a cylindrical portion 41 and an annular support surface 42 integrally formed therewith. The rotating shaft 61 is inserted into the cylindrical portion 41, causing the tip of the rotating shaft 61 to protrude. The annular support surface 42 goes around the outer periphery of the cylindrical portion 41 and supports the center of the lower surface of the pressing pad 20. The lower fastener 40 has an engagement recess 44 that engages with the rotating shaft 61, and rotates integrally with the rotating shaft 61. In this embodiment, the engagement recess 44 is a concave recess provided around the through hole 43 of the cylindrical portion 41.

[0033] The upper fastener 50 is disposed on the abrasive disc 10 side of the polishing unit 30, and clamps the polishing unit 30 between itself and the lower fastener 40. The upper fastener 50 has a boss portion 51 and a flange portion 52 integrally formed therewith. The boss portion 51 passes through the mounting hole 3 of the polishing disc 10. The flange portion 52 is pressed against the surface of the coating layer 4 of the polishing disc 10, and clamps the polishing unit 30 between itself and the annular support surface 42 of the lower fastener 40. A screw hole 53 is formed on the inner surface of the boss portion 51 to be screwed into the screw on the outer circumferential surface of the rotating shaft 61.

[0034] In this embodiment, the flange portion 52 has a plurality of through holes 54 provided around the screw hole 53. A protrusion or claw of a fastening tool is fitted into the through holes 54 to rotate and fasten the upper fastener 50 when the boss portion 51 is screwed onto the rotating shaft 61. Preferably, a retaining ring 59 is fitted onto the outer periphery of the cylindrical boss portion 51 with the boss portion 51 inserted into the mounting hole 3 of the abrasive disc 10 and the through hole 21 of the pressing pad 20.

[0035] The drive unit 60 has a rotating shaft 61 that protrudes outside the machine. The rotating shaft 61 has an engaging protrusion 62 that engages with the engaging recess 44 of the lower fastener 40, and rotates the lower fastener 40 as one unit. In this embodiment, the engaging protrusion 62 of the rotating shaft 61 is a convex member provided at the base of the rotating shaft 61. By engaging the engaging protrusion 62 of the rotating shaft 61 with the engaging recess 44 of the lower fastener 40, when the rotating shaft 61 rotates, the lower fastener 40 also rotates as one unit.

[0036] 5 is a cross-sectional view of a polishing apparatus according to one embodiment of the present invention, in which (A) is a cross-sectional view showing an attached state of the polishing unit, and (B) is an enlarged cross-sectional view of a region R shown in (A).

[0037] As shown in (A), the polishing unit 30 including the polishing disc 10 and the pressure pad 20 is clamped by a lower fastener 40 and an upper fastener 50 and is attached to the drive device 60 so as to rotate integrally with the rotation shaft 61 of the drive device 60.

[0038] As shown in (B), with the polishing unit 30 clamped, the boss portion 51 of the upper fastener 50 is inserted into the mounting hole 3 of the polishing disc 10 and the through hole 21 of the pressure pad 20. By screwing the screw of the rotating shaft 61 into the screw hole 53 of the boss portion 51, the polishing unit 30 is clamped between the flange portion 52 of the upper fastener 50 and the annular support surface 42 of the lower fastener 40. With the polishing unit 30 clamped, a gap (distance C) exists between the boss portion 51 of the upper fastener 50 and the cylindrical portion 41 of the lower fastener 40.

[0039] In a conventional grinder of the type in which a grinding unit consisting of a grinding disc and a pad is attached by clamping it, as exemplified in Patent Document 1, the flange part of the nut is in direct contact with the grinding surface of the grinding disc, and in such a conventional grinder, if the nut is repeatedly tightened every time the grinding disc is replaced, the flange part of the nut that contacts the grinding surface will wear out. As the wear of the flange part of the nut that contacts the grinding surface progresses, it will no longer be able to clamp the grinding unit, and the nut will lose its function as a fastener.

[0040] In contrast, in the abrasive disc 10 according to one embodiment of the present invention, as shown in the cross-sectional view of Fig. 5, a coating layer 4 (4a) is provided in the region of the abrasive surface 2 of the abrasive disc 10 that contacts the flange portion 52 of the upper fastener 50. Unlike the abrasive surface 2 to which the abrasive 2a is affixed, the surface 4a of the coating layer 4 is smooth, so that the flange portion 52 of the upper fastener 50 contacts the smooth surface 4a of the coating layer 4, and wear of the flange portion 52 in the region that contacts the abrasive disc 10 is reduced.

[0041] Furthermore, in conventional grinders of the type exemplified in Patent Document 1, when the grinding unit is clamped, there is no gap between the boss part of the nut and the pad, and between the pad and the boss part at the base of the shaft. As a result, when wear progresses on the flange part of the nut that contacts the grinding surface, the grinding unit no longer clamps the workpiece, and no grinding force is exerted even when the grinding disc is pressed against the workpiece.

[0042] In contrast to this, in the polishing apparatus 100 according to one embodiment of the present invention, as shown in (B), when the polishing unit 30 is clamped, a gap (distance C) exists between the boss portion 51 of the upper fastener 50 and the tubular portion 41 of the lower fastener 40. Due to the existence of a gap between the boss portion 51 and the tubular portion 41, the polishing unit 30 is clamped between the flange portion 52 and the annular support surface 42, and the polishing force of the polishing unit 30 is exerted. [Manufacturing procedure for abrasive discs]

[0043] FIG. 6 is a perspective view for explaining a manufacturing procedure of an abrasive disc according to one embodiment of the present invention.

[0044] Illustratively, the abrasive disc 10 according to this embodiment can be manufactured using an abrasive cloth 11 and a washer 14 for forming the coating layer 4. Illustratively, the abrasive cloth 11 can be a commercially available abrasive cloth in which an abrasive surface 2 to which an abrasive material 2a is fixed is provided on one side of a flexible substrate 1.

[0045] First, as shown in (A), a mounting hole 3 is provided in a disk-shaped coated abrasive 11. In this embodiment, slits 5 are further provided extending radially from the mounting hole 3. Illustratively, the mounting hole 3 and the slits 5 can be provided by punching.

[0046] Next, a washer that functions as the covering layer 4 is inserted into the mounting hole 3, and as shown in (B), the coated abrasive 11 and the washer are integrated by pressing. The covering layer 4 is located on the side of the coated abrasive 11 facing the abrasive surface 2 to which the abrasive 2a is fixed. In this embodiment, the mold used for pressing is a mold in which the area around the mounting hole 3 is recessed. As a result, the area around the mounting hole 3 of the abrasive disc 10 is recessed.

[0047] Finally, the portion of the washer protruding onto the surface opposite the polished surface 2 is folded back and crimped to form a folded back portion 4b, thereby forming a coating layer 4 on the periphery of the mounting hole 3.

[0048] In this embodiment, the washer is inserted into the mounting hole 3 and attached, thereby preventing the abrasive cloth 11, which has been pressed to create a recess around the mounting hole 3, from returning to its original flat shape and enabling the recessed shape to be maintained.

[0049] As described above, according to the present invention, it is possible to provide an abrasive disc, abrasive unit, and abrasive device that reduce wear of fasteners. According to the abrasive disc 10 of the present invention, a coating layer 4 having a smooth surface is provided in an annular shape around the mounting hole 3 on the side of the abrasive surface 2. This coating layer 4 functions as a means for preventing wear caused by the fasteners 50 for attaching the abrasive disc 10 to the drive unit 60, and wear of the fasteners 50 that progresses every time the abrasive disc 10 is replaced is reduced.

[0050] Furthermore, with the polishing apparatus 100 according to the present invention, when the polishing unit 30 is clamped, a gap (distance C) exists between the boss portion 51 of the upper fastener 50 and the tubular portion 41 of the lower fastener 40. Due to the existence of a gap between the boss portion 51 and the tubular portion 41, the polishing unit 30 is effectively clamped between the flange portion 52 and the annular support surface 42, and the polishing force of the polishing unit 30 is exerted. [Other formats]

[0051] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

[0052] In the above embodiment, metal is exemplified as the material of the coating layer 4, but the material of the coating layer 4 is not limited to metal. Various materials such as resin, fiber, rubber, etc. can be used for the coating layer 4.

[0053] In the above embodiment, the engaging protrusion 62 is formed on the rotating shaft 61, and the engaging recess 44 is formed on the lower fastener 40, thereby engaging the engaging protrusion 62 with the engaging recess 44, but the recess-relationship between the engaging protrusion 62 and the engaging recess 44 may be reversed. That is, the engaging recess may be formed on the rotating shaft 61, and the engaging protrusion may be formed on the lower fastener 40, thereby engaging the engaging recess with the engaging protrusion.

[0054] In the above embodiment, the pressing surface 22 of the pressing pad 20 is configured with the ridges 22a and the grooves 22b, but the form of the pressing surface 22 is not limited to this. As long as the abrasive disc 10 can exert abrasive force, various pressing surfaces 22 having various structures and shapes can be adopted.

[0055] In the above embodiment, the covering layer 4 is formed by crimping a washer to the peripheral portion of the mounting hole 3, but the method of attaching the washer to the mounting hole 3 is not limited to this. For example, the covering layer 4 can be formed by adhering a washer to the peripheral portion of the mounting hole 3.

[0056] In the above embodiment, synthetic resin is exemplified as the material of the pressure pad 20, but the material of the pressure pad 20 is not limited to synthetic resin. Various materials such as natural resin, thermoplastic resin, metal, rubber, etc., other than synthetic resin, can be used for the pressure pad 20. [Explanation of symbols]

[0057] 1 Flexible base material 2 Polished surface 2a Abrasive material 3 Mounting holes 4 Covering layer 5 Slit 10 Abrasive discs 11 Abrasive cloth paper 20 Pressure Pad 21 Through hole 22 Pressing surface 22a Convex strip 22b Groove 23 Through hole 30 Polishing Unit 40 Lower fastener 41 Cylindrical part 42 Annular support surface 43 Through hole 44 Engagement recess 50 Upper fastener 51 Boss 52 Flange 53 Screw hole 54 Through hole 59 Retaining Ring 60 Drive unit 61 Rotational axis 62 Engagement protrusion 100 Polishing equipment

Claims

1. An abrasive disc is formed from a disk-shaped flexible substrate and has an abrasive surface on one side of which an abrasive material is fixed, a mounting hole is provided in the center, and a coating layer having a smooth surface is provided in an annular shape around the mounting hole on the side of the polishing surface; The abrasive surface has a recessed area around the mounting hole, and a plurality of slits penetrating the abrasive disc are provided radially from the periphery of the hole around the recessed mounting hole.

2. 2. The abrasive disc of claim 1, wherein the coating layer is provided in an area that contacts a fastener for attaching the abrasive disc to a drive device.

3. 3. The abrasive disc according to claim 1, wherein the coating layer is formed by attaching a washer to a peripheral edge of the mounting hole.

4. An abrasive disc according to any one of claims 1 to 3, A pressure pad is placed on the surface of the abrasive disc opposite to the abrasive surface; It is a combination of The pressing pad has a through hole in the center that communicates with the mounting hole of the abrasive disc when the pressing pad is placed on the abrasive disc, and the surface that is placed on the abrasive disc is formed into a pressing surface having projections and recesses.

5. 5. The polishing unit according to claim 4, wherein the pressing surface is constituted by a plurality of ridges extending radially from a central portion to an outer periphery and grooves between the plurality of ridges.

6. A polishing unit according to claim 4 or 5, A drive unit having a rotating shaft protruding outside the machine; a lower fastener having an engagement portion that engages with the rotating shaft so as to rotate integrally with the rotating shaft; an upper fastener that holds the polishing unit between the upper fastener and the lower fastener; Equipped with The lower fastener is a cylindrical portion through which the rotating shaft is inserted and from which a tip end of the rotating shaft projects; an annular support surface that surrounds the outer periphery of the cylindrical portion and supports the center portion of the lower surface of the pressure pad; Integral to the The upper fastener is a boss portion that passes through the mounting hole of the abrasive disc; a flange portion that is pressed against the coating layer of the abrasive disc and that sandwiches the abrasive unit between the flange portion and the annular support surface of the lower fastener; and a boss portion having an inner surface formed with a thread to be screwed onto the thread of the rotating shaft.

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