Abrasive disc with reflective material

Abstract

To provide an abrasive disc such as a fiber disc which is visible easily in the dark, whether being rotated or not, when being used by being fitted to a hand tool such as a grinder.SOLUTION: An abrasive disc to be used by being fitted to a hand tool and rotated, and having a substrate, and a polishing layer provided on one surface of the substrate, has at least a region of a partial reflector on the opposite side rear surface of the polishing layer so that visibility in a rotational state of the abrasive disc is improved in an approximate plane view in the dark having a small amount of outside light.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a rotating abrasive disc for use with a disc grinder, etc. In particular, it relates to an abrasive disc such as a fiber disc that allows easy visual confirmation of whether it is rotating during use, thereby improving safety. [Background technology]

[0002] Grinders, sanders, and the like are known as hand tools configured to rotate a tip tool such as an abrasive disc. These hand tools can be used, for example, to perform grinding, polishing, and other processing work, such as deburring between steel plates of a ship's bottom before painting. The bottom of a ship is a dark place with little external light, and workers may work while illuminating their hands with a headlamp or the like. Even if a worker tries to start the hand tool and check whether the abrasive disc is actually rotating, the amount of external light can be low, making it difficult to see. Not being able to easily see whether the abrasive disc is rotating can be very dangerous during work.

[0003] Conventionally, a configuration has been proposed for indicating the driving status of a tool tip in a power tool, which includes a housing, a tool tip attached to the housing, a motor housed within the housing and driving the tool tip, a baffle plate housed within the housing and guiding the cooling air of the motor to flow in a predetermined direction, an accommodation space formed in the baffle plate, an indication means housed in the accommodation space and indicating the driving status of the tool tip with light, and a light-transmitting cover covering the indication means on the outer surface of the housing (JP Patent Publication No. 2007-175833: Patent Document 1).

[0004] Furthermore, when polishing with a fiber disc or the like, the disc gradually wears down and its outer diameter becomes smaller during the work, but when working in a dark place, it is difficult to grasp the state of wear, making it difficult to determine when to replace the disc. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-175833 Summary of the Invention [Problem to be solved by the invention]

[0006] The previously proposed configurations aimed to reduce the number of parts related to the status notification unit that notifies the drive status of the tip tool in the power tool, but were cumbersome because they required changing the configuration of the power tool itself. Until now, no means had been proposed for easily visually checking the rotation status and replacement time of the grinding disc while working in a dark place with a commercially available power hand tool, etc.

[0007] The present invention aims to provide an abrasive disc for use with a hand tool that allows the rotation state to be visually confirmed even in the dark. In particular, the present invention aims to provide a rotating abrasive disc that has an abrasive layer on one surface and a rotation state indication on the other surface, making it easy to visually confirm the rotation state from above when sanding the surface of a boat or car body. This aims to improve the safety of work using a hand tool and an abrasive disc in the dark.

[0008] Another object of the present invention is to provide an abrasive disc, such as a fiber disc, that is subject to wear during abrasive work and that allows the user to easily determine when it is time to replace the abrasive disc, even when working in a dark place. [Means for solving the problem]

[0009] One embodiment of the present invention is an abrasive disc that comprises a substrate and an abrasive layer on one side of the substrate, which is intended to be attached to a hand tool and rotated for use, and is characterized by having an area of ​​at least partial reflector on the back surface opposite the abrasive layer, so as to improve the visibility of the rotating state of the abrasive disc when viewed approximately in a plane in a dark place with little external light.

[0010] According to the abrasive disc of the present invention, by having a reflective material area on at least a portion of the back surface opposite the abrasive layer, the reflective material appears as a bright ring when rotating, allowing visual confirmation of whether or not the disc is rotating. The size and shape of the reflective material area are preferably determined according to the reflective performance of the reflective material and the rotation speed of the hand tool so that the rotation of the disc can be sufficiently seen in a dark place with little external light. The reflective material may extend from at least a portion of the outer periphery of the abrasive disc toward the center, thereby making it possible to clearly indicate the outer periphery of the abrasive disc during rotation and improving safety.

[0011] Preferably, the reflective area can be determined so that it is visible as a ring when the abrasive disc is rotated with a hand tool in a dark place. The reflective area can be determined based on the brightness of the ring that is defined when rotated. As long as it is visible as a bright ring when rotated, the reflective area on the back surface of the abrasive disc can be in the shape of a fan or a ring, or it can be in the shape of a logo such as a trademark.

[0012] By doing so, an abrasive disc can be obtained that allows an operator to visually check the rotation state while working in a dark place. The reflective material may be a luminous reflective material including a retroreflective sheet, and it is preferable that the reflective material has a certain level of reflective performance as a measure of brightness when viewed with the naked eye.

[0013] The abrasive disc may be attached to the hand tool via a back-up pad, and the area of ​​reflective material may extend from at least a portion of the outer periphery of the back-up pad to a predetermined position outside the outer periphery of the back-up pad.

[0014] By doing as described above, the abrasive disc is attached to a hand tool via a backup pad and wears down during abrasive work. For example, when the light from the reflective material, which can be seen with the naked eye in a dark place, disappears, it is possible to replace the abrasive disc, making it extremely easy to determine when it is time to replace it.

[0015] The abrasive disc may be a fiber disc.

[0016] The hand tool may be a grinder or sander. [Effects of the Invention]

[0017] According to the present invention, safety can be improved when working with a rotating abrasive disc using a hand tool in a dark place. Since the rotation state can be monitored by changing the configuration of the abrasive disc without changing the configuration of the hand tool itself, the present invention can be easily introduced at low cost and contributes to the safety of workers during abrasive and grinding work.

[0018] Furthermore, according to the present invention, changes in the outer shape of the abrasive disc, such as reduction in the outer shape due to polishing or grinding, can be easily seen even in the dark, making it easy to know when to replace it. This eliminates the need to frequently interrupt work to visually check for the need for replacement, and avoids the risk of overlooking the replacement time and damaging components of the hand tool (such as a backup pad). This improves work efficiency and safety. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic plan view of a known disc grinder. [Figure 2] Figure 2(A) is a schematic plan view (top) and XY end view (bottom) of a conventional fiber disc. Figure 2(B) is a schematic plan view (top) and XY end view (bottom) of a conventional fiber disc used with a backup pad. [Figure 3] Figure 3(A) is a schematic plan view (top) and XY end view (bottom) of a fiber disk with a reflector according to one embodiment of the present invention, and Figure 3(B) is a schematic plan view (top) and XY end view (bottom) of a fiber disk with a reflector according to one embodiment of the present invention used with a back-up pad. [Figure 4A] FIG. 4A is a photograph of a fiber disk with a reference reflector. [Figure 4B] FIG. 4B is a photograph taken in a dark place of the fiber disc of the reference example attached to the grinder and rotated. [Figure 5A] FIG. 5A is a photograph of a fiber disk with reflector material according to one embodiment. [Figure 5B] FIG. 5B is a photograph taken of one example fiber disc mounted on a grinder and rotated in the dark. [Figure 6] FIG. 6 is a photograph taken in a dark place of a fiber disk of another example mounted on a grinder and rotated. [Figure 7] Figure 7(A) is a schematic plan view of a fiber disk with a reflector according to another embodiment of the present invention, and Figure 7(B) is a schematic plan view of a fiber disk with a reflector according to another embodiment of the present invention used with a back-up pad. DETAILED DESCRIPTION OF THE INVENTION

[0020] Various features of the present invention will now be described, along with preferred embodiments thereof, which are not intended to be limiting of the present invention, with reference to the drawings. The drawings are simplified and schematic for illustrative purposes, and are not necessarily to scale. Reference numerals may refer to identical parts, articles, etc.

[0021] FIG. 1 shows a known grinder 1 used together with a polishing disk according to the present invention. The grinder 1 has a housing 10, and at the lower end of one end in the longitudinal axis direction of the housing 10, it is configured to rotatably hold a polishing disk 100. A wheel cover 11 can be fixed to the lower end of this one end to suppress the scattering of chips and dust of the workpiece generated during the machining operation and protect the operator (user) from the polishing disk 100. The wheel cover 11 may not be used depending on the type of hand tool, the work content, the diameter of the polishing disk, etc. The polishing disk 100 is detachably mounted on a shaft (not shown) extending in a direction orthogonal to the longitudinal axis direction of the housing 10, and can be rotationally driven by the user starting the throttle handle 12. The user can grip the throttle handle 12 and / or the vibration-proof handle 13 while using the grinder 1.

[0022] The illustrated example can be the posture of the grinder 1 as seen by the operator when the user abuts the lower surface (polishing surface) of the polishing disk 100 against the lower workpiece at a predetermined angle A (for example, 0 degrees < A ≤ 45 degrees). For example, during polishing, the polishing disk 100 can be abutted against a substantially flat surface or a convex curved surface of the workpiece with an inclination of 45 degrees or less, 30 degrees or less, 10 degrees or less, etc. Alternatively, the polishing disk 100 can be abutted parallel to the surface of the workpiece (A = 0 degrees).

[0023] Examples of the polishing disk 100 that can be mounted on the grinder 1 include a fiber disk, a grinding stone, a rubber pad, a brush, a blade, etc. The polishing disk 100 is generally circular (doughnut plate-shaped) with a central hole for attaching to the shaft. The shape of the fiber disk may be circular (doughnut plate-shaped), or may be octagonal (polygonal) or flower-shaped. The user can select an appropriate polishing disk 100 according to the desired machining operation and mount it on the grinder 1. In the illustrated example, the backup pad used when attaching a flexible polishing disk 100 such as a fiber disk to the grinder 1 is omitted.

[0024] The upper view of Figure 2(A) is a plan view of a conventional fiber disc 200. The fiber disc 200 is in the shape of a donut plate (annular substrate) with a predetermined diameter. The fiber disc 200 generally uses a vulcanized fiber as a base material, and a resin coating layer with numerous abrasive grains embedded in it is formed on one side of the base material as an abrasive layer, and is flexible. The lower view of Figure 2(A) is an XY end view of the fiber disc 200, and in the illustrated example, the abrasive layer 101 forms the bottom surface of the disc. The opposite side of the abrasive layer 101 generally consists of a backing material attached to a base material 102, and the surface of the backing material forms the back surface 102s of the fiber disc 200.

[0025] 2(B) shows the backup pad 14 and fiber disc 200 used when attaching them to a hand tool such as a grinder, and the lower figure shows their XY end faces. The backup pad 14 has an annular portion including an outer periphery and a central portion offset in the direction perpendicular to the surface of the annular portion, and may be made of rubber, resin, metal, or the like.

[0026] The upper diagram in Figure 3(A) is a plan view of a fiber disk 300 equipped with a reflective material according to one embodiment of the present invention. In addition to the configuration of the conventional fiber disk 200, this disk is equipped with a reflective material that extends from a portion of the outer periphery 102p of the back surface 102s toward the center. In the illustrated example, the reflective material region 102r extends in an approximately fan-shaped manner from a portion of the outer periphery 102p to a portion of the inner periphery that corresponds to the edge of the central mounting hole, and the central angle θ of the approximately fan-shaped configuration is 90 degrees.

[0027] The reflective area 102r may be formed on the back surface 102s of the fiber disc so as to define at least a portion of the outer edge 102p of the disc. This allows the worker to grasp the outer edge of the disc when working in a dark place, reducing the risk of the worker accidentally touching the edge during rotation, or the risk of the disc coming into contact with something other than the workpiece during rotation and being broken and scattered.

[0028] The reflective material area 102r can be formed by attaching a so-called retroreflective material (such as a reflective film, reflective cloth, or phosphorescent film) that reflects incident light toward the light source to a predetermined area on the back surface 102s. The retroreflective material used to form the reflective material area 102r may be a glass bead type that can clearly reflect light even in dark places, even with weak light, thanks to the light-collecting properties of the glass beads and the action of a light-reflecting layer. It may be an open type in which glass beads are attached to a reflective film, an encapsulated lens type in which glass beads are coated with a transparent resin, or an encapsulated lens type in which glass beads are coated with a transparent resin with an air gap between them. The retroreflective material may also be a prism type (soft, hard, or metal-deposited) using a polyhedron (such as a triangular pyramid or regular tetrahedron).

[0029] Alternatively, the reflective material area 102r may be formed by applying a high-intensity luminous paint or the like to a predetermined area on the rear surface 102s, or by attaching a high-intensity luminous paint sheet.

[0030] For example, a luminous reflector (Reflite (registered trademark) series) manufactured by Mipox Corporation can be used as the reflector for forming the reflective area according to the present invention.

[0031] As shown in Figure 3(B), a fiber disk 300 equipped with a reflective material according to the present invention can also be attached to a grinder via a backup pad 14. The thickness of the reflective material (102r) is less than 1 mm (for example, 0.5 mm) and is flexible, so the thickness of the reflective material attached to the backside of the disk does not pose a problem when attaching or using it.

[0032] The inventors of the present invention attached a fiber disk equipped with the reflective material of the present invention to a commercially available grinder and tested the relationship between the area of ​​the reflective material and visibility when used in a dark place with little external light.

[0033] Figure 4A is a photograph (taken with an iPhone 8 manufactured by Apple Inc., USA) of a fiber disc equipped with a reference reflector (indicated by a white arrow) used in the test. The fiber disc used was a product HCA (outer diameter: 5 inches) manufactured by Nihon Kenshi Co., Ltd. The reflector used was a product number 8114 manufactured by Mipox Corporation (reflection performance (incident angle 5°, observation angle 0.2°): 14 cd / lx.m 2 The central angle (θ) of the approximately fan-shaped reflector was less than 10°.

[0034] This was attached to a commercially available grinder (Hitachi Koki Co., Ltd., product name: G10SH3), and the visibility was confirmed when it was rotated in a dark place. The rotation speed was 4,300 rpm.

[0035] Figure 4B is a photograph taken at that time (taken with an iPhone (registered trademark) 8 manufactured by Apple Inc., USA). The reflective material is barely visible in the photograph. When viewed with the naked eye, it is thought that the effect of afterimages and dark adaptation make the object appear brighter than when photographed with a camera, but in this case the annular shape was barely or barely visible even to the naked eye, and visibility in the dark was insufficient.

[0036] Figure 5A is a photograph (taken with an iPhone (registered trademark) 8 manufactured by Apple Inc.) of a fiber disc equipped with the reflective material (indicated by the white arrow) of the example used in the test. The reflective material area was similar to that of the reference example, except that it was approximately fan-shaped with a central angle of about 90°, extending from the outer periphery to the inner periphery of the disc.

[0037] 5B is a photograph of the fiber disk of the example attached to the grinder in the same manner as in the reference example and rotated in a dark place. The grinder and camera conditions were the same as in the reference example.

[0038] In the photograph of Figure 5B, the reflector appears to have a slightly wider angular range than the actual reflector area (approximately 90°) due to factors such as the shutter speed. When viewed visually, it appears clearly as a bright ring due to the afterimage effect, and it is easy to see that it is rotating in a dark place.

[0039] As described above, if the reflective material area on the fiber disc is too small, the brightness of the ring observed when the disc is rotated in the dark using a specified hand tool is insufficient, making it difficult to determine whether the disc is rotating or not. Therefore, the amount of reflective material applied to the back surface of the fiber disc is preferably selected based on the reflective performance of the reflective material, etc., so that the brightness of the ring observed when the disc is rotated in the dark using a specified hand tool is sufficient. Such a reflective material area can be a portion of the back surface of the fiber disc, or the entire back surface of the fiber disc. Figure 6 shows a photograph taken with a camera after applying the same reflective material as in the above example to the entire back surface of a fiber disc rotated under the same conditions. A ring of the same shape as the reflective material area was clearly visible, indicating that the disc was rotating.

[0040] The outer diameter of the fiber disc according to the present invention may be in the range of 4 to 7 inches. The hole diameter of the fiber disc may be in the range of 12 to 25 mm. The rotation speed of the grinder used with the fiber disc may be in the range of 500 to 13,000 rpm. In light of the purpose of use of the present invention, the reflective performance of the reflective material used may not need to be very high, depending on the light intensity of the light source (headlights, etc.), the angle of incidence (position of the headlights, etc. and the grinding disc), the angle of reception (position of the worker's eyes), etc. The retroreflection coefficient of the reflective material when measured in accordance with JIS Z 9117 while changing the angle of incidence and observation angle is 3 cd / lx.m 2 The above may be acceptable. The color of the reflective material may be selected arbitrarily. The type, area, shape, etc. of the reflective material may be selected arbitrarily as long as it is attached to a commercially available grinder and is visible as a bright ring when rotating. The reflective material area may be a continuous area or a discontinuous area.

[0041] FIG. 7(A) is a schematic diagram showing the determined reflective material area of ​​a fiber disc 400 of another embodiment. The reflective material area 103r extends from the outer peripheral edge 102p of the fiber disc to a circle C inside the outer peripheral edge (central angle θ = 90 degrees). As shown in FIG. 7(B), circle C can be set relative to the outer peripheral edge 14p of the backup pad 14 (e.g., outside the outer peripheral edge 14p). For example, if the fiber disc is tilted and brought into contact with a workpiece during polishing, not only the abrasive layer of the fiber disc but also the entire surface, including the back surface, may be gradually polished from the outer peripheral edge, resulting in a reduction in the outer diameter. Abrasive discs whose outer peripheral edge 102p has been polished to a point close to the outer peripheral edge 14p of the backup pad 14 must be replaced. By determining the reflective material area 103r as shown, an operator can replace the fiber disc when the width of the glowing ring visible in the dark becomes smaller or when the light of the ring disappears completely.

[0042] It will be apparent to those skilled in the art that many modifications can be made without departing from the spirit and scope of the present invention. Therefore, it should be understood that the embodiments of the present invention are illustrative only and do not limit the scope of the present invention. [Explanation of symbols]

[0043] 300 Abrasive disc with reflective material 101 Abrasive layer of abrasive disc 102 Abrasive disc substrate (backing material) 102s abrasive disc backside 102r Reflective area 102p Outer edge of abrasive disc 14 Backup Pad

Claims

1. An abrasive disc having a base material and an abrasive layer provided on one side of the base material, which is to be attached to a hand tool via a backup pad and rotated for use, wherein only one abrasive disc is attached to the hand tool for use; The abrasive disc has an area where a retroreflective material is attached or applied at least partially to the rear surface opposite to the abrasive layer so as to improve the visibility of the rotation state of the abrasive disc when viewed from above in a dark place with little external light, The abrasive disc is characterized in that the region extends from at least a portion of the outer periphery of the back surface to a predetermined position outside the outer periphery of the back-up pad.

2. 2. The abrasive disc of claim 1, wherein the region is determined so as to be visually recognized as a ring when the abrasive disc is rotated with the hand tool in the dark.

3. 10. The abrasive disc of claim 1, wherein the abrasive disc is a fiber disc.

4. 10. The abrasive disc of claim 1, wherein the hand tool is a grinder or sander.

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