Rotary tools

Abstract

Provided is a rotary tool 10 to be attached to an output shaft of a power tool, the rotary tool 10 comprising a resin base plate 11 formed in a disc shape from a resin material, and a plurality of grindstone tips 18 disposed along a circumferential direction on an outer periphery of the resin base plate 11. Each of the grindstone tips 18 includes a holding plate 21, and an abrasive grain layer 22 held on the holding plate 21, and is independently and integrally fixed to the resin base plate 11.

Description

[Technical field]

[0001] The present invention relates to a rotary tool that is attached to a rotary shaft and is used to grind the surface of a material such as concrete or stone. [Background technology]

[0002] In grinding operations using power tools such as electric tools, air tools, and engine tools, such as disc grinders and sanders, to grind the surfaces of materials to be ground, such as concrete, stone, and metal, a grinding wheel, i.e., a rotating tool, is used as the tip tool. The rotating tool has a cup-type base plate with a cup-shaped central portion and an outer periphery extending in the radial direction, and is disc-shaped, i.e., wheel-shaped, with multiple grinding tips, i.e., abrasive grain layers, fixed to the outer surface of the base plate. The rotating tool is used by attaching the output shaft, i.e., spindle, of the power tool to the center of the base plate.

[0003] In grinding work using such power tools, the grinding tip is pressed against the workpiece, so the vibration caused by the impact during grinding is directly transmitted to the worker, making it difficult to work continuously for long periods of time. Therefore, as described in Patent Document 1, a rotary tool has been proposed that is equipped with a vibration reduction mechanism between the mounting part of the power tool and the rotary tool, thereby reducing the vibration to the worker during grinding work. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-226650 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the rotary tool described in Patent Document 1 has a configuration in which a ring-shaped elastic body is brought into contact with a metal substrate and sandwiched between a washer and the rotary tool, and there is a problem that the weight of the rotary tool as a whole increases due to the increased number of parts. Also, when the substrate is made of a material other than metal that has a vibration reducing effect, there is a problem that deformation of the substrate itself puts a strain on the abrasive layer, i.e., the joint of the polishing tip, and the product life is shortened.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a rotating tool that reduces vibration transmitted to an operator while suppressing a decrease in product life, while suppressing an increase in weight. [Means for solving the problem]

[0007] The present invention is a rotary tool mounted on the output shaft of a power tool, comprising a resin substrate formed into a disk shape from a resin material, and a plurality of grinding chips arranged circumferentially on the outer periphery of the resin substrate, the grinding chips including a holding plate and an abrasive grain layer held by the holding plate, and each of the grinding chips is independently fixed integrally to the resin substrate. Effect of the Invention

[0008] Since the multiple grinding chips with the abrasive layer and the holding plate are arranged on the resin substrate, the weight of the rotary tool is suppressed. Since the abrasive layers are separated from each other and fixed to the resin substrate, the vibration applied to the abrasive layer during grinding is absorbed by the resin substrate, and the vibration transmitted to the operator is reduced. Since the abrasive layer is bonded to the holding plate, damage to the abrasive layer is suppressed, and the reduction in the product life is suppressed. [Brief description of the drawings]

[0009] [Figure 1] 1 is a side view showing a power tool to which a rotary tool according to an embodiment is attached; [Diagram 2] FIG. 2 is an enlarged cross-sectional view of the rotary tool shown in FIG. [Diagram 3]FIG. [Figure 4] FIG. 2 is an enlarged front view showing one grinding tip attached to a resin substrate. [Diagram 5] FIG. 3 is an enlarged cross-sectional view of part A in FIG. 2. [Figure 6] 5 is a cross-sectional view taken along line BB in FIG. [Figure 7] These are cross-sectional views showing the state in which the surface of a workpiece is being ground using a rotating tool attached to a power tool, where (A) shows the state in which all of the abrasive grain layers are pressed against the surface of the workpiece, and (B) shows the state in which only a portion of all of the abrasive grain layers are pressed against the surface of the workpiece. [Figure 8] 1 is a cross-sectional view showing a state in which a grinding tip attached to a flexible resin substrate follows and grinds the undulations and undulations of a surface to be ground. [Figure 9] FIG. 11 is a front view showing one grinding tip in a rotary tool according to another embodiment. [Figure 10] 10 is an enlarged cross-sectional view taken along line CC in FIG. [Figure 11] FIG. 11 is a cross-sectional view showing a grinding tip in a rotary tool according to another embodiment. [Figure 12] FIG. 11 is a cross-sectional view showing a grinding tip in a rotary tool according to another embodiment. [Figure 13] FIG. 11 is a cross-sectional view showing a grinding tip in a rotary tool according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, common members are designated by the same reference numerals.

[0012] Fig. 1 shows a power tool 1 used for grinding the surface of a workpiece such as stone or metal. This power tool 1 is an electric tool having an output shaft 3 extending perpendicularly to a case body 2 at the tip of which an electric motor (not shown) is built, and the output shaft 3 is driven and rotated by the electric motor. A grinding wheel as an end tool, that is, a rotating tool 10, is attached to the output shaft 3 by a mounting bracket 4 on the rear side and a mounting bracket 5 on the front side. The mounting bracket 5 is a nut that is screwed into a male thread (not shown) provided at the tip of the output shaft 3.

[0013] As shown in Fig. 2, the rotating tool 10 has a resin base plate 11 formed into a disk shape from a resin material. The resin base plate 11 includes a mounting portion 12 that is mounted on the output shaft 3 by mounting brackets 4 and 5, and a mounting portion 13 that is offset forward of the output shaft 3 with respect to the mounting portion 12, and an inclined wall portion 14 is provided between the mounting portion 12 and the mounting portion 13. The inclined wall portion 14 is generally shaped like a truncated cone, and the resin base plate 11 is a cup type in which the central portion is formed into a cup shape by the mounting portion 12 and the inclined wall portion 14, and the mounting portion 13, which is the outer periphery, extends in the radial direction. When the resin base plate 11 is mounted on the output shaft 3, the surface that faces the workpiece is called the front or front surface, and the opposite surface is called the back or back surface.

[0014] As the resin material of the resin substrate 11, fiber reinforced plastic (FRP) containing fiber and resin is used. As the fiber reinforced plastic, GFRP is used, which uses epoxy resin as the base material and glass fiber as the reinforcing material. However, the base material, i.e., the matrix, may be other thermosetting resin such as unsaturated polyester or phenol resin, or may be GFRTP using thermoplastic resin such as polyamide resin, polycarbonate resin, polyphenylene sulfide resin, or may be CFRP or CFRTP using carbon fiber as the reinforcing material. In this way, the resin substrate 11 made of a resin material such as fiber reinforced plastic is elastically deformable and has flexibility compared to substrates made of metal or hard resin.

[0015] A collar 15 made of a metal material is fixed to the center of the mounting part 12, and the collar 15 has a hollow shaft part 16 through which the output shaft 3 passes, and a flat part 17 that is disposed on the front surface side of the mounting part 12. The resin board 11 is attached to the output shaft 3 by abutting the mounting bracket 4 against the back surface of the mounting part 12 and fastening the mounting bracket 5 to the surface of the flat part 17.

[0016] 3, a plurality of grinding chips 18 are arranged in the circumferential direction on the outer periphery of the resin substrate 11, i.e., on the surface of the outer periphery of the attachment portion 13. In this rotating tool 10, a total of ten grinding chips 18 are arranged separately and independently on the outer periphery of the resin substrate 11 at regular intervals in the circumferential direction, and each grinding chip 18 is fixed to the resin substrate 11 and integrated therewith.

[0017] Each grinding chip 18 includes a metal holding plate 21 fixed to the surface of the resin substrate 11 and an abrasive layer 22 held by the holding plate 21. The holding plate 21 is attached to a range spanning the radial center of the mounting portion 13 offset forward of the output shaft 3 relative to the mounting portion 12, and the abrasive layer 22 is attached to the radial outer periphery of the holding plate 21. The abrasive layer 22 is a hard sintered body formed by heating and sintering a mixed powder of abrasive grains made of granular synthetic diamond and a bond (metal bond) in a heating furnace, and is also called a segment, sintered chip, or simply a chip. As the abrasive grains, abrasive grains such as CBN (cubic boron nitride) and GC (green silicon carbide) can be used instead of synthetic diamond. In addition, as the metal used for the metal bond, cobalt, nickel, iron, tungsten carbide, tungsten, bronze, etc., or known materials obtained by mixing these can be used. Moreover, instead of a metal bond, any bond such as a resinoid bond, a vitrified bond, etc. may be used. The abrasive layer 22 may be a so-called sintered diamond (PCD) having a low ratio of a bond.

[0018] Fig. 4 is an enlarged front view showing one grinding tip 18 attached to the resin substrate 11. Fig. 5 is an enlarged cross-sectional view of part A in Fig. 2, and Fig. 6 is a cross-sectional view taken along line BB in Fig. 4.

[0019] 4 and 5, the holding plate 21 has an arc-shaped outer peripheral surface 23 and an inner peripheral surface 24 that each extend in the circumferential direction of the resin substrate 11, and the outer peripheral surface 23 and the inner peripheral surface 24 have the same center of curvature O, which is the central axis of rotation of the circular resin substrate 11. Both end faces 25 in the circumferential direction of the holding plate 21 are curved surfaces that are convex outward from the end faces 25. The material of the holding plate may be a hard resin or the like.

[0020] 3, if the distance between the outer peripheral surfaces 23 of the two grinding tips 18 facing each other across the rotation center axis O, i.e., the diameter of the rotary tool 10, is D1, and the distance between the inner peripheral surfaces 24 of the two grinding tips 18 facing each other is D2, the diameter D1 is 100 mm and the diameter D2 is 84 mm. The tip angle α in the circumferential direction of each grinding tip 18 is 24 degrees, and the gap angle β in the circumferential direction between two circumferentially adjacent grinding tips 18 is 11 degrees.

[0021] The abrasive layer 22 fixed to the holding plate 21 has an outer peripheral surface 26 and an inner peripheral surface 27. The outer peripheral surface 26 is an arcuate surface with a radius of curvature R1 having a center of curvature O, similar to the outer peripheral surface 23 of the holding plate 21, and is continuous and flush with the outer peripheral surface 23. In contrast, the inner peripheral surface 27 is an arcuate surface with a radius of curvature R3 having a center of curvature P at a position shifted radially outward from the center of curvature O of the outer peripheral surface 26.

[0022] In FIG. 4, the imaginary line M is a circular arc surface with a curvature radius R2, with the center of curvature O of the outer peripheral surface 26 as the center of curvature. If the inner peripheral surface 27 is a circular arc surface indicated by the imaginary line M, and the centers of curvature of the outer peripheral surface 26 and the inner peripheral surface 27 are the same point O, the radial thickness dimension of the abrasive layer 22 is approximately the same along the circumferential direction. In contrast, as shown in FIG. 4, if the center of curvature O of the inner peripheral surface 27 is shifted radially outward from the center of curvature O of the outer peripheral surface 26, the thickness W2 of both ends in the circumferential direction of the abrasive layer 22 becomes thicker than the thickness W1 of the central portion in the circumferential direction. That is, the abrasive layer 22 has a portion formed on the circumferential end side that is thicker in the radial direction than the central portion in the circumferential direction. This allows the impact in the rotational direction applied to both ends of the abrasive layer 22 during grinding to be appropriately distributed, and it is possible to suppress damage caused by localized force application. The thickness W1 is 5 mm, while the thickness W2 is 8 mm.

[0023] As shown in FIG. 5, the thickness of the resin substrate 11 is t1, and the thickness of the holding plate 21 is t2. The thickness t1 is 1.4 mm, and the thickness t2 is 1 mm. The thickness t2 is preferably thin and lightweight while ensuring the strength required for fixing to the resin substrate 11, and is formed to be the same as or thinner than the thickness t1. The thickness t2 is preferably in the range of 0.1 to 0.8 times the thickness t1, and more preferably in the range of 0.5 to 0.75 times the thickness t1. Furthermore, the height of the abrasive layer 22, that is, the dimension in the direction along the central axis of rotation, is h, and the height h is 4 mm. The front surface of the abrasive layer 22 is the grinding surface 29 that is pressed against the surface of the workpiece to be ground.

[0024] Both circumferential end faces of the abrasive layer 22 are inclined surfaces 28 inclined with respect to a radial line. The inclined surfaces 28 have an outward inclined surface 28a radially outward from the radial center of the abrasive layer 22, and an inward inclined surface 28b radially inward from the center. The outward inclined surface 28a faces the radially outward direction of the rotating tool 10, with the radial line that contacts the protruding end of the convexly bent surface of the inclined surface 28 as the center. On the other hand, the inward inclined surface 28b faces the radially inward direction of the rotating tool 10.

[0025] The grinding chip 18 has a holding plate 21 and an abrasive layer 22 bonded thereto, and is fixed to the outer periphery of the surface of the resin substrate 11, and the grinding chips 18 are separated from each other. Since the abrasive layer 22 is bonded to the holding plate 21 made of metal or hard resin, it does not tilt or displace relative to the holding plate 21 during grinding. In contrast, as shown in FIG. 3, the region 30 of the resin substrate 11 between the grinding chips 18 adjacent in the circumferential direction is a flexible region that can elastically deform in response to the displacement of the grinding chip 18 during grinding. As a result, the grinding chip 18 can be displaced relative to the resin substrate while maintaining its overall shape without being deformed during grinding. A rotary tool 10 equipped with ten grinding chips 18 has ten flexible regions 30.

[0026] As shown in FIG. 5, the holding plate 21 has a bonding hole 31 penetrating the holding plate 21, and the abrasive layer 22 has a protrusion 32 that enters the bonding hole 31. As shown in FIG. 6, three bonding holes 31 are formed at intervals in the circumferential direction of the resin substrate 11, and the protrusion 32 of the abrasive layer 22 enters each bonding hole 31. Therefore, the abrasive layer 22 is bonded to the surface of the holding plate 21 and the protrusion 32 is bonded to the inner peripheral surface of the bonding hole 31, so that the holding plate 21 and the abrasive layer 22 are bonded in a stepped or zigzag shape in the circumferential direction of the resin substrate 11, as shown in FIG. 6. This makes it possible to suppress the abrasive layer 22 from peeling off from the holding plate 21, and to suppress a decrease in product life.

[0027] To manufacture the abrasive tip 18, the holding plate 21 with holes machined as the joining holes 31 is placed in a sintering die, and with the holding plate 21 placed, a mixture of abrasive grains and bond is filled into the sintering die and heated. As a result, the abrasive grain layer 22 to which the holding plate 21 is joined is insert molded in the sintering die. As described above, the holding plate 21 and the abrasive grain layer 22 are joined in a stepped shape, which increases the joining strength.

[0028] The abrasive layer 22 is inserted into the joining hole 31 formed through the holding plate 21, but a groove with a bottom may be formed in the holding plate 21 and the abrasive layer 22 may be inserted into the groove, so that the holding plate 21 and the abrasive layer 22 are joined at a stepped joining surface.

[0029] The holding plate 21 is fixed to the resin substrate 11 by two rivets 33. As shown in FIG. 5, the resin substrate 11 has a mounting hole 34 as a grinding chip fixing portion, and each holding plate 21 has two tapered rivet holes 35. The rivet 33 is a protrusion that protrudes from the holding plate 21 toward the resin substrate 11, and the rivet 33 as a protrusion is inserted into the mounting hole 34 as a grinding chip fixing portion to fix the holding plate 21 to the resin substrate 11. When the holding plate 21 and the resin substrate 11 are fixed by the rivet 33, the holding plate 21 can be formed of a metal plate thinner than the resin substrate 11, and imbalance in rotation caused by variations in the weight of the grinding chip 18 can be suppressed.

[0030] To fix the holding plate 21 to the resin substrate 11 with rivets 33 which are separate from the resin substrate 11 and the holding plate 21, the rivets 33 are attached in advance to the mounting holes 34 of the resin substrate 11, the rivets 33 protruding from the mounting holes 34 of the resin substrate 11 are inserted into the crimping holes 35 of the holding plate 21, and the tip of the rivet 33 is plastically deformed from the side opposite to the insertion side of the crimping hole 35. Alternatively, the rivets 33 as the protruding parts may be fixed to the holding plate 21 by welding, and the rivets 33 may be inserted into the mounting holes 34 to plastically deform the heads of the rivets 33.

[0031] The radial positions of the rivets 33 relative to the holding plate 21 are radially overlapped in the recessed grooves 36 formed by the inner circumferential surface 27 of the abrasive layer 22, as shown in Fig. 4. In this way, by utilizing the recessed grooves 36 formed by the inner circumferential surface 27 and arranging the rivets 33 in the spaces, the fixing strength between the holding plate 21 and the resin substrate 11 can be increased without increasing the size of the holding plate 21. Furthermore, the abrasive layer 22 is set to have a smaller thickness at the circumferential center than at the circumferential end sides, and the rivets 33 are arranged on the circumferential center side, so that the thickness of both ends in the circumferential direction can be increased, and therefore the contact area between the grinding surface 29 of the abrasive layer 22 and the member to be ground can be increased, and an increase in surface pressure can be suppressed.

[0032] Fig. 7 is a cross-sectional view showing a state in which the surface S of the workpiece V is ground by the rotary tool 10 attached to the power tool. Fig. 7(A) shows a state in which the grinding surfaces 29 of all the abrasive grain layers 22 are pressed against the workpiece S of the workpiece V, and even if the workpiece is tilted within the range of angle a around the rotation axis O, the grinding surfaces 29 of all the abrasive grain layers 22 are kept pressed. On the other hand, Fig. 7(B) shows a state in which some of the grinding surfaces 29 of all the abrasive grain layers 22 are in contact with the workpiece S of the workpiece V, and by tilting the rotation axis O at angle b, the grinding surfaces 29 of some of the abrasive grain layers 22 are pressed against the workpiece S, and the other abrasive grain layers 22 are separated from the workpiece S.

[0033] When the abrasive layer 22 is pressed against the grinding surface S of the grinding member V, the resin substrate 11 has flexibility, so that the inclined wall portion 14 elastically deforms so that the inner diameter on the front side becomes larger, and the grinding surface 29 of each abrasive layer 22 is pressed against the grinding surface in its entirety, and grinding is performed. In this state, the edge of the abrasive layer 22 is unlikely to bite into the grinding surface S, and the weight of the grinding tip 18 is also suppressed, so that the grinding surface S is prevented from being excessively ground. In other words, the pressing force for performing the grinding work appropriately can be made to have a certain range, so that the grinding amount can be easily controlled. This allows the grinding surface S to be ground with high precision. Moreover, the vibration applied to the abrasive layer 22 is absorbed by the flexible resin substrate 11, so that the vibration transmitted to the operator is reduced. Since the abrasive layer 22 is bonded to the holding plate 21, no external force that would deform the abrasive layer 22 is applied, and the product life of the abrasive layer 22 can be prevented from being shortened.

[0034] As shown by the symbol F in FIG. 7(A), when the grinding surface 29 of the abrasive layer 22 is pressed against the surface S to be ground, if there is a protrusion (also called a wavy or undulation) on the surface S to be ground, the protrusion will abut against the end face of the abrasive layer 22. At this time, as shown in FIG. 8, the inter-chip region 30 between two adjacent grinding chips 18 in the resin substrate 11 can be elastically deformed, so that one end face of each grinding chip 18 displaces in a direction away from the surface S to be ground, and rides up the protrusion to grind the protrusion. That is, the grinding chip 18 displaces following the surface S to be ground, enabling a uniform grinding operation with little unevenness in the amount of grinding. Even in such an operation, excessive grinding caused by the edge of the abrasive layer 22 biting into the surface S to be ground is suppressed. Furthermore, since the resin substrate 11 does not contain metal materials, even if it is repeatedly elastically deformed due to the displacement of the grinding chip 18, metal fatigue does not occur, and the occurrence of damage to the resin substrate 11 can be suppressed, thereby suppressing a decrease in the product life.

[0035] Since the end face of the abrasive layer 22 is an inclined surface 28 inclined with respect to a radial line, even if a protrusion of a workpiece to be ground hits the end face, the abrasive layer 22 is prevented from being damaged, and the corners formed by the inclined surface 28 are prevented from interfering with the deformation of the resin substrate 11. If the inclined surface 28 is formed by the outward inclined surface 28a and the inward inclined surface 28b, the inclined surface 28 can be formed on the end face without increasing the circumferential length of the abrasive layer 22.

[0036] The circumferential tip angle α of the grindstone tip 18 is set to 24 degrees, and the gap angle β is set to 11 degrees, but the angles at which the region 30 in the resin substrate 11 between two adjacent grindstone tips 18 can exhibit flexibility are not limited to these angles. Experiments have shown that the tip angle α may be 10 degrees or more and 30 degrees or less, and the gap angle β may be 7 degrees or more and 20 degrees or less. Furthermore, the thickness t1 of the resin substrate 11, the thickness t2 of the holding plate 21, and the height h of the abrasive layer 22 are not limited to the above-mentioned values.

[0037] The retaining plate 21 is attached in an area spanning the radial center of the mounting portion 13, which is offset with respect to the attachment portion 12. Therefore, as shown by the imaginary line T in Figure 2, even if the abrasive layer 22 wears, the connection portion 19 between the inclined wall portion 14 and the mounting portion 13 can be protected.

[0038] FIG. 9 is a front view showing one grinding tip 18 in a rotary tool according to another embodiment, and FIG. 10 is an enlarged cross-sectional view taken along line CC in FIG.

[0039] In this grinding tip 18, bonding grooves 41 are formed in the outer peripheral surface 23 and end surface 25 of the holding plate 21, and protrusions 42 that fit into each bonding groove 41 are provided in the abrasive layer 22. In this manner, the bonding portion between the abrasive layer 22 and the holding plate 21 has the bonding grooves 41 and the protrusions 42, and the holding plate 21 and the abrasive layer 22 are bonded in a stepped or zigzag shape in the circumferential direction of the resin substrate 11, increasing the bonding strength.

[0040] 11 and 12 are cross-sectional views showing an abrasive tip 18 according to another embodiment.

[0041] In the grinding tip 18 shown in Fig. 11, a bonding groove 43 is formed on the back surface of the abrasive grain layer 22, and a protrusion 44 that fits into the bonding groove 43 and bonds is provided protruding forward on the surface of the holding plate 21. The bonding groove 43 and the protrusion 44 are provided in a plurality of pieces, for example, three pieces each, along the circumferential direction, similar to the bonding holes 31 and the protrusions 32 shown in Figs. 4 and 5.

[0042] In the grinding chip 18 shown in Fig. 12, a joining groove 45 is formed on the surface of the holding plate 21, and a protrusion 46 joined to the joining groove 45 is provided on the abrasive grain layer 22. The joining grooves 45 and the protrusions 46 are provided in pairs in the radial direction, and further in multiple pairs, for example, three pairs, in the circumferential direction. In this form of grinding chip 18, the holding plate 21 and the abrasive grain layer 22 are joined in a stepped shape in the circumferential direction, and are also joined in a stepped shape in the radial direction.

[0043] As shown in Figures 9 to 12, by joining the holding plate 21 and the abrasive layer 22 in a stepped manner, the joining strength can be increased, and even if vibrations are applied to the abrasive layer 22 during grinding, the abrasive layer 22 and the holding plate 21 are prevented from separating or being damaged, and a decrease in the product life is suppressed.

[0044] 13 is a cross-sectional view showing an abrasive tip 18 according to another embodiment, in which a coaxial joining hole 47 is formed in the holding plate 21 and the rivet 33, and a protrusion 48 joined to this joining hole 47 is provided in the abrasive layer 22. By joining the protrusion 48 to the holding plate 21 and the rivet 33 in this manner, the joining strength between the abrasive layer 22, the holding plate 21 and the rivet 33 can be increased. In this embodiment, the holding plate 21 and the rivet 33 are integrally molded when the abrasive layer 22 is sinter-molded.

[0045] The present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the present invention. For example, the number of grindstone chips 18 attached to the resin substrate 11 is not limited to 10 as in the illustrated embodiment, and various numbers of the rotary tool can be used. Similarly, the outer diameter of the rotary tool 10 can be various diameters depending on the material to be ground. The abrasive layer 22 is fixed to the holding plate 21 by incorporating the holding plate 21 into a mold and heat-treating it in a sintering furnace when the abrasive layer 22 is molded by sintering, so that the abrasive layer is joined to the holding plate 21 during sintering. However, after the abrasive layer is molded, the abrasive layer may be fixed to the holding plate by an electrodeposition method using electroplating or a welding method using a brazing material. [Industrial Applicability]

[0046] The rotary tool of the present invention is applied to grinding a surface to be scanned, such as concrete or stone.

Claims

1. A rotary tool attached to an output shaft of a power tool, a resin substrate formed into a disk shape from a resin material; A plurality of grindstone chips are arranged along a circumferential direction on an outer periphery of the resin substrate, Each of the plurality of abrasive chips includes a holding plate and an abrasive grain layer held on a surface of the holding plate; Each of the plurality of grinding chips is independently and integrally fixed to the resin substrate by fixing the holding plate to which the abrasive grain layer is bonded to the resin substrate, the resin substrate includes a mounting portion that is mounted on an output shaft, a mounting portion that is offset forward from the mounting portion and to which the grinding tip is fixed, and an inclined wall portion that is provided between the mounting portion and the mounting portion; a height from a surface of the mounting portion to a surface of the attachment portion is greater than a height from the surface of the attachment portion to a surface of the abrasive layer, and a height from the surface of the attachment portion to a surface of the holding plate is smaller than a height from the surface of the holding plate to a surface of the abrasive layer, A rotating tool, wherein a region between adjacent grinding tips in the circumferential direction of the resin substrate and a region between the grinding tips from the inclined wall portion in the radial direction have flexibility that allows elastic deformation during grinding.

2. The rotary tool according to claim 1 , wherein the resin substrate is made of a fiber-reinforced plastic containing fibers and a resin.

3. The rotary tool according to claim 1 , wherein the abrasive layer has an inclined surface on an end surface in a circumferential direction that is inclined with respect to a radial line.

4. A rotary tool attached to an output shaft of a power tool, a resin substrate formed into a disk shape from a resin material; A plurality of grindstone chips are arranged along a circumferential direction on an outer periphery of the resin substrate, Each of the plurality of grindstone chips includes a holding plate and an abrasive grain layer held by the holding plate, and each of the plurality of grindstone chips is independently fixed integrally to the resin substrate; the abrasive layer has an inclined surface on an end surface in a circumferential direction, the inclined surface being inclined with respect to a radial line; The inclined surface has an outward inclined surface in which an end surface radially outer than a radial center portion is inclined outward, and an inward inclined surface in which an end surface radially inner than the radial center portion is inward, The outwardly inclined surface faces a radially outward direction of the rotary tool, and the inwardly inclined surface faces a radially inward direction of the rotary tool.

5. A rotary tool attached to an output shaft of a power tool, a resin substrate formed into a disk shape from a resin material; A plurality of grindstone chips are arranged along a circumferential direction on an outer periphery of the resin substrate, Each of the plurality of grindstone chips includes a holding plate and an abrasive grain layer held by the holding plate, and each of the plurality of grindstone chips is independently fixed integrally to the resin substrate; The abrasive layer has an arc-shaped outer peripheral surface and an arc-shaped inner peripheral surface whose center of curvature is radially outward from the center of curvature of the outer peripheral surface, and the abrasive layer has a portion whose radial thickness is greater on the circumferential end side than on the circumferential center side.

6. A rotary tool as described in claim 1, wherein the retaining plate is attached in a range spanning the radial center of the mounting portion.

7. The rotary tool described in claim 1, wherein the abrasive layer is arranged so that a portion of the abrasive layer overlaps with the holding plate in the thickness direction of the resin substrate and another portion of the abrasive layer overlaps with the holding plate in the circumferential direction of the resin substrate, thereby being joined to the holding plate in a stepped manner in the circumferential direction of the resin substrate.

8. The rotary tool according to claim 7, wherein the abrasive layer is formed by sintering a mixed powder of abrasive grains and bond and fixed to the holding plate, and is joined to the holding plate in a stepped manner by entering a groove or hole formed in the holding plate.

9. The resin substrate has a grindstone chip fixing portion formed of a groove or a hole, a protrusion protruding toward the resin substrate is provided on the holding plate; The rotary tool according to claim 1 , wherein the holding plate and the resin substrate are fixed together by inserting the protruding portion into the grindstone tip fixing portion.

10. A rotary tool mounted on an output shaft of a power tool, comprising: a resin substrate formed into a disk shape from a resin material; A plurality of grindstone chips are arranged along a circumferential direction on an outer periphery of the resin substrate, Each of the plurality of grindstone chips includes a holding plate and an abrasive grain layer held by the holding plate, and each of the plurality of grindstone chips is independently fixed integrally to the resin substrate; The resin substrate has a grindstone chip fixing portion formed of a groove or a hole, a protrusion protruding toward the resin substrate is provided on the holding plate; The protruding portion is inserted into the grindstone chip fixing portion, thereby fixing the holding plate and the resin substrate, A rotary tool, wherein a radial position of the protrusion relative to the holding plate overlaps a groove formed by an arcuate inner circumferential surface of the abrasive layer.

11. 3. The rotary tool according to claim 1, wherein a tip angle of each of the grinding tips in the circumferential direction is in the range of 10 degrees to 30 degrees.

12. 3. The rotary tool according to claim 1, wherein a gap angle in the circumferential direction between the grinding tips adjacent in the circumferential direction is in the range of 7 degrees or more and 20 degrees or less.

13. A rotary tool attached to an output shaft of a power tool, a resin substrate formed into a disk shape from a resin material; A plurality of grindstone chips are arranged along a circumferential direction on an outer periphery of the resin substrate, The abrasive tip includes a holding plate and an abrasive grain layer held by the holding plate, a protruding portion extending in a direction of a central axis of rotation of the resin substrate is provided on one of the holding plate and the abrasive layer, and a joint portion into which the protruding portion fits is provided on the other of the holding plate and the abrasive layer; the holding plate and the abrasive layer are joined to each other in a stepped manner in a circumferential direction of the resin substrate by the protrusions entering the joint portion, the rotating tool.

14. A rotary tool as described in claim 13, wherein the abrasive layer is formed by sintering a mixed powder of abrasive grains and bond and fixed to the holding plate, and is joined to the holding plate in a stepped manner by entering a groove or hole formed in the holding plate.

15. A rotary tool as described in claim 1, wherein the retaining plate is in the range of 0.1 to 0.8 times the thickness of the resin substrate.

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