Intermediate pad for hand grinder

Abstract

In an embodiment where a grinding sheet is attached to a hand grinder for use, the heat generated during grinding is appropriately removed. [Solution] The disc-shaped intermediate pad has a first surface equipped with a first hook fastener for connecting to the back surface of the abrasive sheet, and a second surface on the opposite side of the first surface equipped with a second hook fastener for connecting to a disc holder attached to the rotating shaft of a hand grinder. A central through-hole is provided in the region including the center of the intermediate pad, penetrating from the first surface to the second surface, with the radius of the central hole being 16% or more and 80% or less of the radius of the intermediate pad. Multiple outer peripheral through-holes are provided on the outer periphery of the intermediate pad, penetrating from the first surface to the second surface, and when the outer circumference is defined as the region between the outer circumference corresponding to the outer edge of the intermediate pad and the inner circumference 32% inward from the outer circumference, the area ratio of the through-holes to the outer peripheral region is 15% or more and 50% or less.

Description

[Technical Field]

[0001] The present invention relates to an intermediate pad for a hand grinder. [Background technology]

[0002] It is known that abrasive sheets (also called abrasive discs, hereinafter referred to as "abrasive sheets") are attached to hand grinders for purposes such as removing relatively small weld beads and spot weld marks. In this case, for example, a disc holder is fixed to the rotating shaft of the hand grinder by screws or the like, and the abrasive sheet is attached to the disc holder. A hook-and-loop fastener is used to secure the disc holder and the abrasive sheet together. [Overview of the project]

[0003] An intermediate pad according to one embodiment of the present disclosure is a substantially disc-shaped intermediate pad used attached to the rotating part of a hand grinder, comprising a first surface having a first hook fastener for coupling with the back surface of an abrasive sheet, and a second surface on the opposite side of the first surface having a second hook fastener for coupling with a disc holder attached to the rotating shaft of the hand grinder, wherein a central through-hole is provided in the region including the center of the intermediate pad, penetrating from the first surface to the second surface, the radius of the central hole being 16% or more and 80% or less of the radius of the intermediate pad, and a plurality of outer peripheral through-holes are provided on the outer periphery of the intermediate pad, penetrating from the first surface to the second surface, and in the intermediate pad, when the region between the outer circumference corresponding to the outer edge of the intermediate pad and the inner circumference 32% inward from the outer circumference of the intermediate pad is defined as the outer peripheral region, the area ratio of the through-holes to the outer peripheral region is 15% or more and 50% or less. [Brief explanation of the drawing]

[0004] [Figure 1] This is a schematic front view of an intermediate pad according to a first embodiment of the present disclosure. [Figure 2]This is a schematic cross-sectional view of the intermediate pad according to the first embodiment of the present disclosure, cut along the line A-A' in Figure 1. [Figure 3] This is a schematic cross-sectional exploded view of the operating section of a hand grinder with an intermediate pad attached according to the first embodiment of the present disclosure. [Figure 4] This is a schematic cross-sectional view of the operating section of a hand grinder with an intermediate pad attached according to the first embodiment of the present disclosure. [Figure 5] This is a schematic front view of an intermediate pad according to the first modified example of this disclosure. [Figure 6] This is a schematic front view of an intermediate pad according to a second modified example of the present disclosure. [Figure 7] This is a schematic front view of an intermediate pad according to a third modified example of this disclosure. [Modes for carrying out the invention]

[0005] The inventors noticed that when using a hand grinder with an abrasive sheet attached for purposes such as removing relatively small weld beads or spot weld marks, burning, damage, and distortion were likely to occur. It was thought that this problem was due to the overheating of the abrasive sheet and the workpiece due to the heat generated during polishing or grinding (hereinafter collectively referred to as "polishing").

[0006] The inventors diligently studied how to solve the problem of heat generated during polishing and obtained the following findings. As a means of appropriately removing the heat generated during polishing, an intermediate pad can be provided between the grinder's disc holder and the polishing sheet, and a path for heat to escape can be formed in the intermediate pad. The disc holder and the polishing sheet are fixed together with hook-and-loop fasteners (mechanical fasteners), and hook-and-loop fasteners have a certain degree of breathability in the lateral direction (parallel to the main surface). Similarly, by arranging hook-and-loop fasteners in the intermediate pad and providing a perforation in the intermediate pad itself, the breathability can be dramatically improved.

[0007] When using a hand grinder with an abrasive sheet attached, the sheet is applied to the grinding surface at a certain angle (for example, about 10 degrees). As a result, the outer edge of the abrasive sheet functions as the grinding surface. Since grinding heat is also generated at the outer edge, it is desirable to have the penetration point at the outer edge (outer edge penetration point).

[0008] Since the intermediate pad is primarily intended for attachment to a hand grinder (although other uses are not excluded), a central through-hole is provided to prevent interference with the disc holder's button (a component used to secure the abrasive sheet to the disc holder through a hole in the center of the abrasive sheet).

[0009] While a larger area of ​​the through-hole is desirable for heat dissipation, the intermediate pad also has the function of fixing the abrasive sheet to the disc holder so as to follow the rotation of the grinder. From the viewpoint of balancing heat dissipation and fixing, it is desirable to keep the area ratio of the through-hole within a certain range. However, since there is a wide range in the fixing force (holding force in the shear direction) of the hook-and-loop fastener, the upper and lower limits of the area ratio of the through-hole are merely guidelines. The area ratio of the through-hole can be appropriately set by a person skilled in the art (the designer of the intermediate pad) taking into consideration the fixing force of the hook-and-loop fastener used, as well as workability, stability, etc. If the fixing force is ensured, through-holes may be provided in places other than the outer circumference and the center.

[0010] Similar products include hook savers (components that prevent wear on the hook material and extend its lifespan) and intermediate soft pads (components that improve localized tracking) used in dust-collecting double-action sanders. These products are not intended for use with a hand grinder with an abrasive sheet attached, nor do they address the issue of heat generation during grinding. The holes in the hook saver and intermediate soft pad are for dust collection purposes, and their position and size differ significantly from the outer peripheral and central penetration portions in the intermediate pad of this disclosure.

[0011] Note that the above is only for the sake of convenience in explaining the background and idea until the completion of the present disclosure, and it should not be used for the interpretation of the content of the present disclosure, especially the limitation of the scope of the claims.

[0012] <Definition> In this specification, the "hand grinder" refers to a tool that attaches an abrasive (or a disk holder with an abrasive attached) to a rotating shaft and performs grinding by a uniaxial rotational operation in one direction. In addition to a so-called hand-held grinder (disk grinder, disk sander), it includes a uniaxial rotational type grinding device provided at the tip of a grinding robot, a uniaxial rotational type single action sander, etc., but does not include a double action sander.

[0013] <First Embodiment> FIG. 1 is a schematic front view of an intermediate pad according to the first embodiment. FIG. 2 is a schematic cross-sectional view of the intermediate pad according to the first embodiment cut along the line A-A' in FIG. 1. FIG. 3 is a schematic exploded cross-sectional view of the operating part of a hand grinder with the intermediate pad according to the first embodiment attached. FIG. 4 is a schematic cross-sectional view of the operating part of a hand grinder with the intermediate pad according to the first embodiment attached. Hereinafter, the intermediate pad according to the first embodiment and the hand grinder using the same will be described with reference to FIGS. 1 to 4.

[0014] The intermediate pad 100 is used by being attached to a disk holder attached to the rotating operating part of a hand grinder and has a substantially disk shape. The hand grinder is typically a hand-held disk grinder, but includes modes or uses in which it is attached to other grinders, single action sanders, grinding robots, etc. and used.

[0015] On the first surface 102 of the intermediate pad 100, a first surface fastener 106 for bonding to the back surface 204 of the polishing sheet 200 is provided. On the second surface 104 of the intermediate pad 100, a second surface fastener 108 for bonding to the disk holder 300 attached to the rotating shaft 400 of the hand grinder is provided. Specifically, as the first surface fastener 106 and the second surface fastener 108, for example, the magic tape of Kuraray Fastening Co., Ltd., the surface fastener of Kitaco Co., Ltd., the surface fastener of 3M Japan Limited, etc. can be used. TM The first surface fastener 106 and the second surface fastener 108 can be directly fixed to each other by any means such as an adhesive, a double-sided tape, welding, etc. An arbitrary base material may be disposed between the first surface fastener 106 and the second surface fastener 108. In this case, the through-hole (described later) is formed so as to penetrate the base material as well. The base material and the surface fastener can also be fixed by any means such as an adhesive, a double-sided tape, welding, etc.

[0016] In a region including the central portion of the intermediate pad 100, a central through-hole 110 penetrating from the first surface 102 to the second surface 104 is provided. That is, the first surface fastener 106 and the second surface fastener 108 do not exist inside the central through-hole 110. The radius R of the central through-hole 110 in a plan view C is 16% or more and 80% or less of the radius R of the intermediate pad. R C may be 20% or more and 70% or less of R, may be 30% or more and 60% or less of R, or may be 40% or more and 50% or less of R.

[0017] The shape of the central through-hole 110 may be circular as shown in FIG. 1, but may be other shapes such as a rectangle, an ellipse, etc. The central through-hole 110 preferably includes the center O of the intermediate pad 100 in order to avoid interference with the rotating shaft 400 of the hand grinder.

[0018] Multiple outer peripheral penetrations 112 are provided on the outer periphery of the intermediate pad 100, extending from the first surface 102 to the second surface 104. That is, the first hook fastener 106 and the second hook fastener 108 are not located inside the outer peripheral penetrations 112. There may be eight or more outer peripheral penetrations 112. The outer peripheral penetrations 112 may be evenly distributed in the circumferential direction in relation to the outer circumference corresponding to the outer edge 114 of the intermediate pad 100. In the example shown in Figure 1, there are 12 outer peripheral penetrations 112, and they are evenly distributed in the circumferential direction. Note that if the outer edge itself is not a circumference, such as when an open-type outer peripheral penetration is provided as described later, the outer circumference is defined as the circumference passing through the point on the outer edge furthest from the center O of the intermediate pad.

[0019] Radial size R of the intermediate pad 100 in the outer peripheral penetration portion 112 H The radius of the intermediate pad 100 can be 5% or more and 32% or less of the radius R. If the outer edge of the intermediate pad 100 is not a circle, the radius of the outer circumference shall be the radius of the intermediate pad 100. H This may be 7% to 30% of R, 9% to 28% of R, 11% to 26% of R, or 13% to 24% of R.

[0020] The shape of the outer peripheral penetration portion 112 may be circular as shown in Figure 1, but it may also be other shapes, such as rectangular or elliptical.

[0021] The outer peripheral penetration portion 112 shown in Figure 1 is a closed type outer peripheral penetration portion that is closed to the outer edge 114 of the intermediate pad 100. However, part or all of the outer peripheral penetration portion may be configured as an open type outer peripheral penetration portion (details will be described later) that is open to the outer edge 114 and constitutes part of the outer edge of the intermediate pad.

[0022] When an outer peripheral region 118 is defined as a region between an outer circumference corresponding to an outer edge 114 of an intermediate pad 100 (in the example shown in FIG. 1, the outer edge and the outer circumference coincide) and an inner circumference 116 inside the outer circumference, the area ratio of through-holes in the outer peripheral region 118 is 15% or more and 50% or less. Here, the through-holes referred to herein include, in addition to the portions of the outer peripheral through-holes 112 that enter the outer peripheral region 118, the portions of the central through-hole 110 that enter the outer peripheral region 118 when a part of the central through-hole 110 is included in the outer peripheral region 118. The area ratio of the through-holes in the outer peripheral region 118 may be 17% or more and 48% or less, or 19% or more and 46% or less, or 21% or more and 44% or less, or 23% or more and 42% or less, or 25% or more and 40% or less.

[0023] The inner circumference 116 is a circumference that is 32% (R in FIG. 1 O ) inside the outer circumference, and its center coincides with the center O of the outer circumference. That is, R in FIG. 1 O is equal to 32% of R, and the radius R of the inner circumference 116 I is 68% of R. The difference R in the radii of the inner circumference and the outer circumference O can be 30%, 28%, 26%, 24%, 22%, or 20% of the radius R of the outer circumference. In this case, R I is 70%, 72%, 74%, 76%, 78%, or 80% of R, respectively.

[0024] In addition to the central through-hole 110 and the outer peripheral through-holes 112, holes penetrating from the first surface 102 to the second surface 104 may be formed.

[0025] The back surface 204 of the abrasive sheet 200 is provided with a third hook fastener 208 that engages with the first hook fastener 106 of the intermediate pad 100 to fix the intermediate pad 100 and the abrasive sheet 200. The front surface 202 of the abrasive sheet 200 may be provided with an abrasive layer 206. Between the abrasive layer 206 and the third hook fastener 208, any layer including a base material may be provided. Any configuration of the abrasive sheet 200 to the abrasive layer 206 can be adopted, including well-known, publicly available, and unpublicly available technologies, so a detailed explanation is omitted. Specifically, the abrasive sheet 200 may be, for example, made by 3M TM Cubitron TM 2 Hooks TM Cross Disc 784F (manufactured by 3M Japan Ltd.), etc., can be used.

[0026] The disc holder 300 is attached to the rotating shaft 400 of the hand grinder. Specifically, for example, as shown in Figures 3 and 4, the rotating shaft 400 may be configured as a screw, and a screw hole may be formed in the center of the back surface 304 of the disc holder 300.

[0027] A fourth hook fastener 306 is provided on the working surface 302 of the disc holder 300, which engages with the second hook fastener 108 of the intermediate pad 100 to fix the intermediate pad 100 and the disc holder 300 together.

[0028] The first hook fastener 106 and the third hook fastener 208 allow the intermediate pad 100 and the abrasive sheet 200 to be reversibly attached and detached. The second hook fastener 108 and the fourth hook fastener 306 allow the intermediate pad 100 and the disc holder 300 to be reversibly attached and detached.

[0029] A button 310 may be provided in the center of the working surface 302 of the disc holder 300 for inserting into the central hole 210 of the abrasive sheet 200 to secure the abrasive sheet 200. However, the button 310 is not essential, and the abrasive sheet 200 and the disc holder 300 may be secured by a bolt (rotating shaft) and a nut. Alternatively, if the fixing force by the hook-and-loop fastener is sufficient, the fixing using the central hole of the abrasive sheet 200 may be omitted altogether.

[0030] Regarding the disk holder 300, any configuration including well-known, publicly available, and unpublicly available technologies can be adopted, so a detailed explanation will be omitted. Specifically, the disk holder 300 could be, for example, 3M TM Disk holders such as the 914E and 914A (manufactured by 3M Japan Ltd.) can be used.

[0031] In Figures 3 and 4, the main body of the hand grinder is omitted from the illustration except for the rotating shaft 400. Since any configuration, including well-known, publicly available, and unpublicly available technologies, can be adopted for the main body of the hand grinder, a detailed explanation is omitted.

[0032] As shown in Figure 4, during use, the intermediate pad 100 is reversibly fixed to the abrasive sheet 200 by the first hook fastener 106 being pressed against and engaging with the third hook fastener 208 located on the back surface of the abrasive sheet 200. Furthermore, the intermediate pad 100 is reversibly fixed to the disc holder 300 by the second hook fastener 108 being pressed against and engaging with the fourth hook fastener 306 located on the working surface of the disc holder 300. In this configuration, the abrasive sheet 200 is reversibly fixed to the disc holder 300 via the intermediate pad 100.

[0033] The disc holder 300 is fixed to the rotating shaft 400 of the hand grinder, and the disc holder 300 rotates in conjunction with the rotation of the rotating shaft 400. As the disc holder 300 rotates, the intermediate pad 100 and the abrasive sheet 200 fixed to it also rotate. Polishing is carried out by pressing the rotating abrasive sheet 200 against the workpiece (not shown). Heat is generated during the polishing process, but the use of the intermediate pad 100 reduces the temperature rise of the abrasive sheet 200 and the workpiece. As a result, burning, damage, distortion, etc., to the abrasive sheet 200 and the workpiece are suppressed.

[0034] Although not limited by theory, the following mechanism can be considered for reducing the temperature rise. Specifically, by providing a perforation on the outer circumference of the intermediate pad, a flow path with low airflow resistance is formed so that it flows from the inside of the intermediate pad through the outer circumference to the outside of the intermediate pad. When the hand grinder rotates, centrifugal force creates a flow that expels air from the inside to the outside of the intermediate pad through the above flow path. This airflow removes the heat generated in the abrasive sheet 200, and the abrasive sheet 200 is cooled.

[0035] During the polishing process, the outer periphery of the polishing sheet 200 is the part that actually contacts the object being polished, and heat is generated at this point. Furthermore, centrifugal force is stronger on the outside of the rotating body. To generate a stronger flow and efficiently remove heat, it is considered particularly effective to place the penetration point on the outer periphery of the intermediate pad. This point was also confirmed by the experiments described later (Test Examples 7 and 8).

[0036] Furthermore, according to the mechanism described above, as long as the central penetration is located inside the outer circumference, it is unlikely to contribute to cooling, and the area ratio of the central penetration is considered to have little effect on cooling performance. This point was also confirmed by the experiments described later (Test Example 5, Test Example 6).

[0037] <Velcro fastener> Each face-fastener can employ any configuration, including well-known, publicly available, or unpublicly available technologies. These will be described in detail below.

[0038] Specifically, for example, a dual-hook type (mushroom type, e.g., 3M) consisting of a combination of two hook materials. TM Dual Lock TM It may be a hook-and-loop fastener (a type of zipper), or it may be a hook-and-loop fastener consisting of a combination of hook material and loop material. In the case of a dual-hook type fastener, both of the two engaging fasteners (the pair of the first fastener 106 and the third fastener 208, and the pair of the second fastener 108 and the fourth fastener 306) are equipped with hook material. In the case of a hook-and-loop type hook-and-loop fastener, if one of the engaging hook-and-loop fasteners (e.g., the first hook-and-loop fastener 106 / the second hook-and-loop fastener 108) has a hook material, the other hook-and-loop fastener (e.g., the third hook-and-loop fastener 208 / the fourth hook-and-loop fastener 306) has a loop material, and if one of the engaging hook-and-loop fasteners (e.g., the first hook-and-loop fastener 106 / the second hook-and-loop fastener 108) has a loop material, the other hook-and-loop fastener (e.g., the third hook-and-loop fastener 208 / the fourth hook-and-loop fastener 306) has a hook material.

[0039] The entire hook-and-loop fastener layer may be composed of a thermoplastic resin. Suitable thermoplastic resins, but are not limited to, include polyolefins, polyisoprene, polybutadiene, fluorinated polymers, chlorinated polymers, polyamides, polyimides, polyethers, polyethersulfones, polysulfones, polyvinyl acetates, copolymers of vinyl acetates such as polyethylene-co-polyvinyl alcohol, polyphosphazenes, polyvinyl esters, polyvinyl ethers, polyvinyl alcohols, and polycarbonates.

[0040] The hook-and-loop fastener layer can be constructed as a "fastening tape" in which hook material or loop material is provided on a base material.

[0041] Suitable materials for the base material are not limited to those listed below, but include polypropylene, polyethylene, polypropylene-polyethylene block copolymer, polyester, vinyl chloride, polyacetate, polyamide, cotton, etc. These materials may be used individually or in combination of two or more types, and these materials may be in the form of molded sheets or films, or in the form of woven fabrics, nonwoven fabrics, knitted fabrics, etc. It is most preferable to construct the base material from a molded article made of the same or similar mixture of polypropylene resin and polyethylene resin as the hook material.

[0042] Suitable materials for forming the hook material include, but are not limited to, polypropylene, polyethylene, polypropylene-polyethylene block copolymer, polyester, vinyl chloride, polyacetate, polyamide, and elastomer. In particular, polypropylene, polyethylene, polypropylene-polyethylene copolymer, polyester, elastomer, or mixtures thereof are suitable for carrying out the present invention.

[0043] Hook materials typically have a structure in which a number of hooks are integrally bonded to a support. The hooks may be arranged in an orderly manner on the support or in a disorderly manner. Here, the integral bonding of the hooks to the support can encompass various forms, such as integration by simultaneous molding with the support, embedding or implanting into the support, or bonding with adhesive. Integration by simultaneous molding with the support is the most preferred. The shape of the hooks is not particularly limited as long as they interlock with the hooks of a pair of hook materials or the loops of a loop material to enable the desired fastening, but as is frequently used in this art, mushroom-shaped, hook-shaped, pin-shaped, or similar projection shapes are preferred. Hook materials can be manufactured by methods described in, for example, Japanese Patent Publication No. 6-500486 and Japanese Patent Publication No. 8-508910.

[0044] In the hook material, the thickness of the support that holds the hook may be in the range of 0.04 to 0.5 mm or 0.04 to 0.13 mm. The height of the hook can be varied over a wide range depending on the desired type of hook material, the thickness of the support, and other factors. The height of the hook (in other words, the sum of the height of the stem and, if any, the thickness of the head formed at the tip of the stem) is usually preferably adjusted to be as small and uniform as possible. The height of the hook is usually preferably in the range of about 0.1 to 1.3 mm, and more preferably in the range of about 0.2 to 0.5 mm, measured from its base.

[0045] The hook is usually 1 cm 2 Preferably, the hooks are arranged on the support at a distribution density of approximately 60 to 1,600 hooks per square centimeter, and more preferably, 1 cm 2 The distribution density is approximately 125 to 700 hooks per unit. Furthermore, the diameter of the hook stem at the portion adjacent to the support (base) is preferably in the range of approximately 0.1 to 0.6 mm, and more preferably in the range of approximately 0.1 to 0.3 mm. The hook head can be of any shape and size.

[0046] When using a hook material attached to a base material, various fastening methods can be used to attach the hook material. Furthermore, the bonding strength between the base material and the hook material achieved by such fastening must be greater than the bonding strength between the hook material and the hook material or loop material during actual use, in order to guarantee the fastening effect of the hook fastener according to the present invention. Suitable fastening methods include, for example, adhesives, heat fusion, bonding by ultrasonic heating, integral molding, sewing, and mechanical fastening by stapler.

[0047] Loop material typically consists of a base material and loops provided on at least one side thereof. Here, the loop is not particularly limited insofar as it has the function of engaging with the hook material, and therefore may be the loop body itself, or it may be a loop-holding material such as woven fabric or nonwoven fabric. If necessary, these loops may be used in combination, or they may be used in the form of a laminate. A laminate can be formed, for example, by laminating the above-described loops onto a plastic film or the like. Furthermore, the loop material may be subjected to processing such as napping, embossing, printing, or dyeing as appropriate.

[0048] Although the loops can be constructed from various materials according to conventional methods, it is preferable that they be constructed from fibrous materials that can effectively intertwine with the hooks of the hook material. Depending on the desired loop shape, the fibrous material can be used in the form of, for example, woven fabrics, nonwoven fabrics, knitted fabrics, or other forms. Furthermore, materials in which fibers are partially bonded to a film so that the bundle of fibers forms a loop can also be advantageously used as loops.

[0049] In a hook-and-loop fastener, the hook material can be locked and secured to the loop material, and the locking of both can be released if necessary. In a dual-hook fastener, one hook material can be locked and secured to the other hook material, and the locking of both can be released if necessary.

[0050] The pair of hook-and-loop fastener layers, with their base surfaces positioned perpendicular to each other, have an internal static shear strength in a direction parallel to their base surface that supports one of the objects to which the base surface is attached from the other object (preferably, for example, a static shear strength parallel to their base surface that is approximately the same as, or greater than, the maximum static shear strength that a pressure-sensitive adhesive can bond with a vertical surface), and also have an internal dynamic tensile strength in a direction approximately perpendicular to their base surface that allows the pair of hook-and-loop fastener layers to be separated by pulling the joined objects without damaging the surfaces of these objects.

[0051] Any loop-engaging material, apparatus, device, method of manufacture, or method of use described in any of the following references (all of which are incorporated herein) may be used in any embodiment described herein: U.S. Patents No. 8,777,919, No. 4,699,622, No. 4,894,060, No. 5,077,870, No. 5,312,387, No. 5,344,691, No. 5,399,219, No. 5,487,809, No. 5,537,722, No. 5,554,146, No. 5,705,013, No. 5,759,317, and No. 5,851,205, No. 5,957,908, No. 5,985,081, No. 6,030,373, No. 6,051,094 , No. 6,075,179, No. 6,190,758, No. 6,406,468, No. 6,544,245, No. 6,575,9 No. 53, No. 7,032,278, No. 7,125,400, No. 7,361,246, No. 7,371,302, No. 7,51 No. 7,572, No. 7,578,812, No. 7,658,813, No. 3,471,903, No. 4,120,718, No. 4, No. 223,067, No. 4,216,257, No. 4,391,687, No. 4,322,875, No. 4,415,615, No. No. 4,454,183, No. 4,563,388, No. 3,353,663, No. 3,408,705, No. 4,977,003 No. 4,679,851, No. 4,819,309, No. 4,776,636, No. 5,308,428, No. 5,135, No. 598, No. 4,910,062, No. 4,887,339, No. 4,985,488, No. 5,679,302, No. 4,89 No. 4,060, No. 5,145,929, No. 5,908,695, No. 5,024,880, No. 5,852,855, No. 5 , No. 040,275, No. 5,149,573, No. 4,290,832, No. 5,453,319, No. 5,614,232, No. 5,691,027, No. 5,713,111, No. 5,671,512, No. 5,625,929, No. 5,671,51 No. 1, No. 5,851,663, No. 5,654,487, No. 5,602,221, No. 5,598,610, No. 5,691,Patent Nos. 021, 7,879,441, 8,277,922, 6,470,540, 6,076,238, 6,592,800, 6,630,239, 6,588,074, 7,217,455, 7,703,179, 6,874,777, 7,140,774, and U.S. Patent Application Publication No. 2004 / 0010217.

[0052] The thickness of the intermediate pad 100 (the thickness of the intermediate pad alone when not attached to the abrasive sheet or disc holder) can be, for example, 2 mm or more and 20 mm or less. The thickness of the intermediate pad 100 may also be 1 mm or more and 30 mm or less, or 2.5 mm or more and 15 mm or less.

[0053] The diameter of the intermediate pad 100 may be the same as the diameter of the abrasive sheet 200, or it may be slightly smaller than the diameter of the abrasive sheet 200. For example, the diameter of the intermediate pad 100 can be between 80 mm and 200 mm. The diameter of the intermediate pad 100 may also be between 90 mm and 190 mm.

[0054] The central penetration portion 110 and the outer peripheral penetration portion 112 can be formed by any method. Specifically, for example, laser cutting, punching (die cutting), etc., can be used.

[0055] <First variation> Figure 5 is a schematic front view of the intermediate pad according to the first modified example. The intermediate pad 100A according to the first modified example will be described below with reference to Figure 5.

[0056] The intermediate pad 100A is an intermediate pad 100 shown in Figure 1, in which a portion of the outer peripheral penetration 112 is made into an open outer peripheral penetration 113. The first hook fastener 106 and the second hook fastener 108 are not present inside the open outer peripheral penetration 113. In the example shown in Figure 5, there are eight closed outer peripheral penetrations 112 and eight open outer peripheral penetrations 113, for a total of 16 outer peripheral penetrations.

[0057] The open outer peripheral penetration portion 113 is open to the outer edge 114 of the intermediate pad 100A and constitutes a part of the outer edge 114 of the intermediate pad 100A. In other words, the open outer peripheral penetration portion 113 can be understood as a notch provided in the outer edge 114 of the intermediate pad 100A. The shape of the open outer peripheral penetration portion 113 may be semicircular as shown in Figure 5, but it may also be other shapes, such as rectangular, semi-elliptical, wedge-shaped (triangle), etc.

[0058] The area ratio of the through-hole to the outer peripheral region 118 is 15% or more and 50% or less. The term "through-hole" here includes the portions of the outer peripheral through-hole 112 and the open-type outer peripheral through-hole 113 that are located within the outer peripheral region 118, as well as the portion of the central through-hole 110 that is located within the outer peripheral region 118 if a portion of the central through-hole 110 is included within the outer peripheral region 118. In the example shown in Figure 5, the area ratio is calculated using the region enclosed by the outer circumference 119, which passes through the part of the outer edge 114 furthest from the center O of the intermediate pad, and the notched portion, as the portion located within the outer peripheral region 118 (the area of ​​the through-hole to the outer peripheral region 118).

[0059] The area ratio of the penetration to the outer peripheral region 118 may be 17% or more and 48% or less, 19% or more and 46% or less, 21% or more and 44% or less, 23% or more and 42% or less, or 25% or more and 40% or less.

[0060] Except for the points mentioned above, the intermediate pad 100A can have the same configuration as the intermediate pad 100 of the first embodiment, including the cross-sectional structure. Therefore, elements common to the intermediate pad 100A and the intermediate pad 100 are given the same reference numerals and names, and detailed explanations are omitted.

[0061] In the first modified example, as in the first embodiment, the intermediate pad 100A can be fixed to the abrasive sheet 200 and the disc holder 300 for use. Therefore, a detailed explanation of how to use the intermediate pad 100A and the configuration of the hand grinder equipped with the intermediate pad 100A will be omitted.

[0062] <Second variation> Figure 6 is a schematic front view of the intermediate pad according to the second modified example. The intermediate pad 100B according to the second modified example will be described below with reference to Figure 6.

[0063] The intermediate pad 100B is the same as the intermediate pad 100 shown in Figure 1, but with the outer peripheral penetration portion 112 replaced by a rectangular open outer peripheral penetration portion 115. The first hook fastener 106 and the second hook fastener 108 are not present inside the open outer peripheral penetration portion 115. In the example shown in Figure 6, 20 rectangular open outer peripheral penetration portions 115 are provided.

[0064] The open outer peripheral penetration portion 115 is open to the outer edge 114 of the intermediate pad 100B and constitutes a part of the outer edge 114 of the intermediate pad 100B. In other words, the open outer peripheral penetration portion 115 can be understood as a notch provided in the outer edge 114 of the intermediate pad 100B. The shape of the open outer peripheral penetration portion 115 may be rectangular as shown in Figure 6, but it may also be other shapes, such as trapezoid, semicircular, semielliptical, wedge-shaped (triangle), etc.

[0065] The area ratio of the through-hole to the outer peripheral region 118 is 15% or more and 50% or less. The through-hole referred to here includes the portion of the open outer peripheral through-hole 115 that is located within the outer peripheral region 118 (in the example shown in Figure 6, the entire open outer peripheral through-hole 115), as well as the portion of the central through-hole 110 that is located within the outer peripheral region 118 if a portion of the central through-hole 110 is included within the outer peripheral region 118. In the example shown in Figure 6, the area ratio is calculated using the region enclosed by the outer circumference 119, which passes through the part of the outer edge 114 furthest from the center O of the intermediate pad, and the notched portion, as the portion located within the outer peripheral region 118 (the area of ​​the through-hole to the outer peripheral region 118).

[0066] The area ratio of the penetration to the outer peripheral region 118 may be 17% or more and 48% or less, 19% or more and 46% or less, 21% or more and 44% or less, 23% or more and 42% or less, or 25% or more and 40% or less.

[0067] Except for the points mentioned above, the intermediate pad 100B can have the same configuration as the intermediate pad 100 of the first embodiment, including the cross-sectional structure. Therefore, elements common to the intermediate pad 100B and the intermediate pad 100 are given the same reference numerals and names, and detailed explanations are omitted.

[0068] In the first modified example, as in the first embodiment, the intermediate pad 100B can be fixed to the abrasive sheet 200 and the disc holder 300 for use. Therefore, a detailed explanation of how to use the intermediate pad 100B and the configuration of the hand grinder equipped with the intermediate pad 100B will be omitted.

[0069] <Third variation> Figure 7 is a schematic front view of the intermediate pad according to the third modified example. The intermediate pad 100C according to the third modified example will be described below with reference to Figure 7.

[0070] The intermediate pad 100C is an intermediate pad 100 shown in Figure 1, in which a portion of the outer peripheral penetration portion 112 is made into a rectangular, internally open outer peripheral penetration portion 117. The first hook fastener 106 and the second hook fastener 108 are not present inside the internally open outer peripheral penetration portion 117. In the example shown in Figure 7, there are 10 outer peripheral penetration portions 112 and 10 rectangular, internally open outer peripheral penetration portions 117, for a total of 20 penetration portions.

[0071] The internally open outer peripheral through-hole 117 is open to the central through-hole 110 of the intermediate pad 100C and constitutes a part of the central through-hole 110. The shape of the open outer peripheral through-hole 115 may be rectangular as shown in Figure 7, but it may also be other shapes, such as trapezoid, semicircular, semielliptical, wedge-shaped (triangle), etc.

[0072] The area ratio of the through-hole to the outer peripheral region 118 is 15% or more and 50% or less. The term "through-hole" here includes the portions of the outer peripheral through-hole 112 and the internally open outer peripheral through-hole 117 that are located within the outer peripheral region 118, as well as the portion of the central through-hole 110 that is located within the outer peripheral region 118 if a portion of the central through-hole 110 is included in the outer peripheral region 118. In the example shown in Figure 7, the entirety of the outer peripheral through-hole 112 and the portion of the internally open outer peripheral through-hole 117 outside the inner circumference 116 are considered to be the portions located within the outer peripheral region 118 (the area of ​​the through-hole within the outer peripheral region 118), and the area ratio is calculated accordingly.

[0073] The area ratio of the penetration to the outer peripheral region 118 may be 17% or more and 48% or less, 19% or more and 46% or less, 21% or more and 44% or less, 23% or more and 42% or less, or 25% or more and 40% or less.

[0074] Except for the points mentioned above, the intermediate pad 100C can have the same configuration as the intermediate pad 100 of the first embodiment, including the cross-sectional structure. Therefore, elements common to the intermediate pad 100C and the intermediate pad 100 are given the same reference numerals and names, and detailed explanations are omitted.

[0075] In the first modified example, as in the first embodiment, the intermediate pad 100C can be fixed to the abrasive sheet 200 and the disc holder 300 for use. Therefore, a detailed explanation of how to use the intermediate pad 100C and the configuration of the hand grinder equipped with the intermediate pad 100B will be omitted.

[0076] <Example of experiment> [Preparation Example 1: A sheet with hook material and loop material provided on both sides] A nylon hook-and-loop fastener (model number: CP-26, manufactured by Kuraray Fastening Co., Ltd.) with adhesive on the back was prepared. The side of the main surface of the substrate with the hook material that does not have a hook material (back side) and the side of the main surface of the loop material of the substrate with the loop material that does not have a loop material (back side) were bonded together to create a sheet with hook material and loop material on both sides.

[0077] [Preparation Example 2: Intermediate pad without outer peripheral penetration] The sheet created in Adjustment Example 1 was punched out using a hydraulic clicker (model number: HMO-10, manufactured by Hori Iron Works Co., Ltd.) and a die (manufactured by Abe Die Manufacturing Co., Ltd.) to form a donut shape with an outer diameter of 100 mm and an inner diameter of 48 mm.

[0078] [Preparation Example 3: Intermediate pad with a circular outer peripheral penetration] Using a die (manufactured by Abe Die Manufacturing Co., Ltd.), circular outer perforations with a diameter of 9 mm were punched out of a circular sheet prepared in the same manner as in adjustment example 2. Eight circular outer perforations with a diameter of 9 mm were evenly spaced in the circumferential direction between 2 mm and 12 mm from the outer edge, and eight more were evenly spaced in the circumferential direction between 10 mm and 20 mm from the outer edge, resulting in a total of 16 outer perforations arranged in a staggered pattern.

[0079] [Adjustment Example 4: Rectangular open-type intermediate pad with outer peripheral penetration] Using a die (manufactured by Abe Die Manufacturing Co., Ltd.), 20 rectangular open outer perforations, each 4 mm wide and 14 mm long, were punched out evenly in the circumferential direction from a circular sheet created in the same manner as in adjustment example 2.

[0080] [Adjustment Example 5: Intermediate pad with a small central penetration] The sheet created in Adjustment Example 1 was punched out using a punch set (model number: TPO-11S, manufactured by TRUSCO Nakayama Co., Ltd.) to form a donut shape with an outer diameter of 100 mm and an inner diameter of 16 mm. Sixteen circular through-holes with a diameter of 9 mm were punched out evenly in the circumferential direction at 2 mm and 12 mm from the outer edge using the punch set (model number: TPO-11S, manufactured by TRUSCO Nakayama Co., Ltd.).

[0081] [Adjustment Example 6: Intermediate pad with a large central penetration] The sheet created in Adjustment Example 1 was punched out using a die (manufactured by Abe Die-Cutting Machinery Co., Ltd.) to form a donut shape with an outer diameter of 100 mm and an inner diameter of 48 mm. Sixteen circular through-holes with a diameter of 9 mm were punched out evenly in the circumferential direction at 2 mm and 12 mm from the outer edge using a punch set (model number: TPO-11S, manufactured by TRUSCO Nakayama Co., Ltd.).

[0082] [Adjustment Example 7: Intermediate pad with the through-hole located in the outer peripheral region] The sheet created in Adjustment Example 1 was punched out using a die (manufactured by Abe Die-Making Co., Ltd.) to form a donut shape with an outer diameter of 100 mm and an inner diameter of 48 mm. Twelve circular outer perforations with a diameter of 9 mm were punched out evenly in the circumferential direction at 6 mm and 15 mm from the outer edge using a punch set (model number: TPO-11S, manufactured by TRUSCO Nakayama Co., Ltd.).

[0083] [Adjustment Example 8: Intermediate pad with the penetration point located inside the outer peripheral area] The sheet created in Adjustment Example 1 was punched out using a die (manufactured by Abe Die-Making Co., Ltd.) to form a donut shape with an outer diameter of 100 mm and an inner diameter of 48 mm. Twelve circular outer perforations with a diameter of 9 mm were punched out evenly in the circumferential direction at 15 mm and 24 mm from the outer edge using a punch set (model number: TPO-11S, manufactured by TRUSCO Nakayama Co., Ltd.).

[0084] [Comparison example: Polishing without an intermediate pad] The rotating shaft of the Makita 9533B hand grinder (780W, 12000rpm) is fitted with 3M TM Attach the disc holder (model number: 914E, manufactured by 3M Japan Ltd.), and then add the abrasive sheet (3M TM Cubitron TM 2 Hooks TMA Cross Disc 784F (model number: 784F HK 120 100, manufactured by 3M Japan Ltd.) was installed. The working surface of the disc holder is provided with a hook material, and the back surface of the abrasive sheet is provided with a loop material. By engaging the hook material and the loop material, the abrasive sheet was fixed to the working surface of the disc holder. In addition, the abrasive sheet has a through hole in the center, and by pressing a button located in the center of the disc holder into the through hole in the abrasive sheet, the abrasive sheet was aligned (ensuring coaxiality between the abrasive sheet and the rotation axis).

[0085] A hand grinder was rotated at 12,000 rpm and, held by hand, was used to grind a workpiece (SUS304, 0.8 mm thick, 75 mm wide, 127 mm high) with a load of 2 kg for 1 minute. A thermal camera (model: CPA-E4, manufactured by Chino Corporation) was used to measure the temperature of the grinding sheet and the ground portion of the workpiece (the temperature of the area showing the highest temperature on the thermal camera monitor). The test was repeated three times.

[0086] [Test Example 1-1: Polishing using Adjustment Example 2] Polishing was performed in the same manner as the control example, except that an intermediate pad created in adjustment example 2 was placed between the polishing sheet and the disc holder (the hook material of the intermediate pad was engaged with the loop material of the polishing sheet, and the loop material of the intermediate pad was engaged with the hook material of the disc holder), and the temperature was measured.

[0087] [Test Example 2: Polishing using Adjustment Example 2] Polishing was performed and the temperature measured in the same manner as in Test Example 1-1, except that the intermediate pad created in Adjustment Example 1 was replaced with the intermediate pad created in Adjustment Example 3.

[0088] The results for the control case, test example 1, and test example 2 are shown in Table 1 below.

[0089] [Table 1]

[0090] From the results above, a significant cooling effect was observed when an outer peripheral penetration was present (Test Example 2) compared to when no intermediate pad was present (control example). Furthermore, in the case of an intermediate pad without an outer peripheral penetration (Test Example 1-1), overheating was more pronounced than in the case without an intermediate pad (control example).

[0091] Furthermore, in Test Examples 1-1 and 2, it was found that the portion of the abrasive sheet closer to the center could be used for polishing, compared to the control example. This was thought to be because the intermediate pad increased the flexibility of the polishing surface.

[0092] The amount of material polished and the surface roughness after polishing were measured using the same method as above, except that the workpiece (S45C, 20mm thick, 180mm wide, 50mm high) was used. The amount of material polished was 64.29g for the control example, 156.25g for Test Example 1-1, and 199.41g for Test Example 2. The surface roughness after polishing was 1.63 for the control example, 1.42 for Test Example 1-1, and 1.25 for Test Example 2. From these results, it was concluded that using an intermediate pad improved cushioning, improved surface roughness, and suppressed the decrease in polishing performance.

[0093] [Test Example 1-2: Polishing using Adjustment Example 2] The polishing process was carried out in the same manner as in Test Example 1-1, except that the polishing was performed using a polishing robot (model number: M-10iA, manufactured by FANUC) with a hand grinder (model number: 9533B, manufactured by Makita) attached to its tip, rather than by hand by a human. The temperature was then measured.

[0094] [Test Example 3: Polishing using Adjustment Example 3] Except for replacing the intermediate pad created in Adjustment Example 2 with the intermediate pad created in Adjustment Example 3, polishing was performed using the same method as in Test Example 1-2 (polishing robot), and the temperature was measured.

[0095] [Test Example 4: Polishing using Adjustment Example 4] Except for replacing the intermediate pad created in Adjustment Example 2 with the intermediate pad created in Adjustment Example 4, polishing was performed using the same method as in Test Example 1-2 (polishing robot), and the temperature was measured.

[0096] The results of Test Examples 1-2, 3, and 4 are shown in Table 2 below.

[0097] [Table 2]

[0098] Based on the above results, it was concluded that the shape of the outer perimeter penetration and whether it is open or closed have little effect on the cooling effect.

[0099] Upon observation of the polished workpiece and polishing sheet after the test, it was found that there was less burning and damage in Test Examples 3 and 4 compared to Test Examples 1 and 2.

[0100] [Test Example 5: Polishing using Adjustment Example 5] The abrasive sheet grit is set to 180 (3M TM Cubitron TM 2 Hooks TM Using a Cross Disc 784F (model number: 784F HK 180 100, manufactured by 3M Japan Ltd.), polishing was performed in the same manner as in Test Example 1-1 (handheld), except that the intermediate pad created in Adjustment Example 2 was replaced with the intermediate pad created in Adjustment Example 5. The temperature was then measured. The weight of the workpiece to be polished was also measured before and after polishing, and the amount of polishing was calculated from the results.

[0101] [Test Example 6: Polishing using Adjustment Example 6] Except for replacing the intermediate pad created in adjustment example 5 with the intermediate pad created in adjustment example 6, polishing was performed in the same manner as in test example 5 (handheld), and the temperature and amount of polishing were measured.

[0102] The results of Test Example 5 and Test Example 6 are shown in Table 3 below.

[0103] [Table 3]

[0104] Based on the above results, it was concluded that the area of ​​the central penetration portion has little effect on the cooling effect.

[0105] [Test Example 7: Polishing using Adjustment Example 7] Except for replacing the intermediate pad created in Adjustment Example 5 with the intermediate pad created in Adjustment Example 7, polishing was performed in the same manner as in Test Example 5 (handheld), and the temperature and amount of polishing were measured.

[0106] [Test Example 8: Polishing using Adjustment Example 8] Except for replacing the intermediate pad created in adjustment example 5 with the intermediate pad created in adjustment example 8, polishing was performed in the same manner as in test example 5 (handheld), and the temperature and amount of polishing were measured.

[0107] The results of Test Example 7 and Test Example 8 are shown in Table 4 below.

[0108] [Table 4]

[0109] Based on the above results, it was concluded that penetrations in the outer region contribute more significantly to the cooling effect than penetrations located further inside.

[0110] <Remarks> All patents, patent applications and publications, publications, and electronically available materials cited herein are incorporated by reference. In the event of any conflict between the disclosures of this application and any of the documents incorporated herein by reference, the disclosures of this application shall prevail. The embodiments and examples described above are provided for clarity of understanding only. No unnecessary limitations should be inferred from them. This disclosure is not limited to the details shown and described, and variations that are obvious to those skilled in the art are included within the scope defined by the claims and the doctrine of equivalents.

[0111] All item names are for the reader's convenience only and should not be used to limit the meaning of the text that follows them unless specifically stated otherwise.

[0112] Various modifications can be made without departing from the spirit and scope of the present invention. These embodiments and other embodiments fall within the scope defined by the claims and the doctrine of equivalents.

Claims

1. An intermediate pad in a roughly circular disc shape, which is attached to the rotating part of a hand grinder for use, A first surface having a first face fastener for bonding with the back surface of the abrasive sheet, It comprises a second surface located opposite the first surface and having a second face fastener for coupling with a disc holder attached to the rotating shaft of a hand grinder, A central penetration portion is provided in the region including the center of the intermediate pad, extending from the first surface to the second surface. The radius of the central penetration portion is 16% or more and 80% or less of the radius of the intermediate pad. Multiple outer peripheral penetrations are provided on the outer periphery of the intermediate pad, extending from the first surface to the second surface. In the aforementioned intermediate pad, when the region between the outer circumference corresponding to the outer edge of the intermediate pad and the inner circumference located 32% inward from the outer circumference by the radius of the intermediate pad is defined as the outer peripheral region, The area ratio of the penetration portion to the outer peripheral region is 15% or more and 50% or less. Mid-pad.

2. The aforementioned outer peripheral penetrations are provided in eight or more locations and are evenly distributed in the circumferential direction. The intermediate pad according to claim 1.

3. The radial size of the outer peripheral penetration portion of the intermediate pad is 5% or more and 32% or less of the radius of the intermediate pad. The intermediate pad according to claim 1.

4. The outer peripheral penetration portion is open to the outer edge of the intermediate pad and includes an open-type outer peripheral penetration portion that forms part of the outer edge of the intermediate pad. The intermediate pad according to claim 1.

5. The outer peripheral penetration portion includes a closed-type outer peripheral penetration portion that is closed to the outer edge of the intermediate pad. The intermediate pad according to claim 1.

6. A hand grinder comprising an intermediate pad according to any one of claims 1 to 5, The aforementioned rotating shaft, The polishing sheet is provided with a third hook fastener on its back surface that engages with the first hook fastener of the intermediate pad to secure the intermediate pad and the polishing sheet, The disc holder is attached to the rotating shaft and has a fourth hook fastener on its working surface that engages with the second hook fastener of the intermediate pad to secure the intermediate pad and the disc holder, Hand grinder.

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