JPH045254Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a rotary grinding tool in which a large number of coated abrasive papers are arranged and bonded radially on the surface of a disc-shaped substrate. This is an attempt to improve the mounting structure.

(Prior Art) Conventionally, a rotary whetstone for grinding and polishing, in which short rail-like coated abrasive paper is adhered radially to the surface of a circular substrate made of plastic or a whetstone, is disclosed in, for example, Japanese Patent Application Laid-Open No. 1983-1999.
It is publicly known from Publication No. 94271. Conventional general grindstones, including this type of grindstone, have been fixed to the drive shaft of a grinder with screws. For more information,
A threaded shaft is provided at the tip of the drive shaft, and after a collar and a rotating grindstone are inserted into this threaded shaft in order, the rotating grindstone is attached by screwing a nut onto the threaded shaft. Therefore, when replacing the grindstone, it was necessary to tighten and loosen the nut using a tool attached to the grinder.

In order to make this grindstone replacement easier, a seat nut corresponding to the above-mentioned nut is integrated with the grindstone, making it possible to attach and detach the grindstone to the drive shaft without using a tightening/loosening tool. There is (Utility Model Publication No. 61-40465). In this case, as shown in FIG. 4, the boss portion 31 of the seat nut 30 is
After inserting into the central mounting hole 33, the seat nut 30 is integrated with the grindstone 32 by caulking and fixing the insertion starting edge of the boss portion 31. In FIG. 4, reference numeral 23 indicates a drive shaft, 24 a screw shaft, 25 a collar, and 34 a mounting surface. The seat nut 30 is formed with a screw hole 35 into which the screw shaft 24 is screwed. According to the rotating whetstone integrally equipped with the seat nut 30, the seat nut 30 can be screwed into the threaded shaft 24 by twisting the entire grindstone 32 by hand, and the seat nut 30 can be attached and detached without using tools. I can do it.

(Problem to be solved by the invention) When the nut body is fixed to the board by caulking as described above, especially when the board is made of a plastic molded product, the rigidity and strength of the board is insufficient. It was difficult to obtain caulking strength, and there was a limit to the amount of torque transmitted from the nut body to the board. Further, even when the substrate is made of a grindstone, torque must be transmitted only by the frictional force of the clamping surfaces due to caulking, and there is a disadvantage that the rotary grindstone can only be applied to grinders with a relatively small drive torque.

In addition, when the nut body is constructed to be caulked, it is necessary to carefully process the caulked portion so that it does not protrude from the mounting surface 34 of the grindstone, and the machining is troublesome. If the caulked portion protrudes from the mounting surface 34, the grindstone 32 cannot be fixed in a normal position, and the rotating surface will be tilted during use, resulting in irregular rotation, resulting in uneven grinding and vibration.

The main purpose of this idea is to improve the structure of the attachment part to the grinder drive shaft in a rotating grindstone in which multiple sheets of coated abrasive paper are adhesively fixed to the substrate, thereby ensuring the reliable transmission of torque to the substrate. purpose.

(Means for solving the problem) Therefore, in this invention, we focused on the fact that the coated abrasive paper is adhesively fixed to the substrate with a thermosetting synthetic resin that has self-adhesive properties, and using this synthetic resin. A screw block corresponding to the nut body in the conventional grindstone is integrally provided.

Specifically, the solution of this invention is to attach a plurality of coated abrasive papers 3 to the surface of a circular substrate 2 having a mounting hole 7 in the center, as shown in FIGS. 1 and 3, for example.
are arranged radially and circumferentially with the back side of each coated abrasive paper 3 partially polymerized on the polishing surface of the coated abrasive paper 3 on the rear side in the rotational direction of the whetstone, and a thermosetting film having self-adhesive properties is applied. The present invention is based on a rotary grinding and polishing tool which is integrally bonded via an adhesive layer made of synthetic resin 10. The substrate 2 is formed in an offset shape in which the portion around the mounting hole 7 is offset toward the back side from the adhesive portion of the coated abrasive paper, and the offset concave portion 12 formed by the offset of the substrate includes the A truncated conical resin block part 13 is integrally provided, which is made by filling the offset recess 12 with a thermosetting synthetic resin 10 so as to be substantially flush with the adhesive layer, and is continuous with the adhesive layer. Further, in the center of the resin block portion 13, a screw hole 15 is formed and bored concentrically with the mounting hole 7, which can be screwed into the screw shaft 19 of the drive shaft 18 of the grinder.

(Function) Accordingly, in this invention, since the resin block portion 13 having the screw hole 15 in the center is formed flush with and continuously on the adhesive layer of the coated abrasive paper 3 from the synthetic resin 10, the synthetic resin 10 The driving torque can be transmitted in a distributed manner over the entire adhesive surface with the substrate 2. Therefore, it is possible to rotate the substrate 2 with a larger drive torque than with conventional grindstones that transmit torque through a very limited caulked structure.

(Embodiment) FIGS. 1 to 3 show an embodiment of this invention.

In FIG. 1, a rotary grinding and polishing tool 1 has a disk-shaped substrate 2 made of an offset resinoid grindstone, and a large number of coated abrasive papers 3 are arranged radially on the front side of the plate. The substrate 2 is integrally formed with a ring-shaped grinding part 4 and a truncated cone-shaped mounting part 5 bulged inside the grinding part 4, and the mounting part 5 is offset from the grinding part 4. A mounting hole 7 for a drive shaft 18 of a grinder, which will be described later, is provided in the center of the top surface 6 of the portion 5. A cap 8 made of a press-molded thin metal plate is inserted into the inner surface of the mounting hole 7.

A coated abrasive paper 3 is integrally adhesively fixed to the grinding surface side of the grinding section 4 of the substrate 2 via an adhesive layer made of a thermosetting synthetic resin 10 having self-adhesive properties such as epoxy resin. This coated abrasive paper 3 is formed in the shape of a short fence, and is arranged so as to go around the grinding part 4 in a radial posture with its long sides overlapping each other vertically, and the end placed on the grinding part 4 is Synthetic resin 1
0 and the overlapping portions of each coated abrasive paper 3 are also adhesively fixed with synthetic resin 10 at the same time. In some cases, a plurality of coated abrasive papers 3 may be combined into a set, arranged in the same manner as described above, and fixed with adhesive.

In order to be able to attach and detach the rotary grinding and polishing tool 1 as described above to the drive shaft 18 of the grinder by directly twisting it by hand without using a tightening/loosening tool.
Using synthetic resin to bond the abrasive coated paper 3,
A resin block portion 13 is integrally provided in the inner surface space of the mounting portion 5 of the substrate 2, that is, in the offset recess 12.
Specifically, as shown in FIG. 2, the offset recesses 12 are also filled with the synthetic resin 10 continuously to the adhesive layer of the synthetic resin 10 applied to the adhesive surface 14 of the coated abrasive paper 3, and the adhesive layer and the surface are bonded. A resin block portion 13 is formed in one shape. When filling the synthetic resin, the peripheral edge of the substrate 2 and the opening of the mounting hole 7 are partitioned by molds (not shown), so the resin block 13 fills the mounting hole 7, and the adhesive layer fills the substrate 2. It does not protrude from the periphery. Before the synthetic resin 10 is cured, the abrasive coated paper 3 described above is planted on the adhesive layer. After the resin block part 13 is completely cured,
A threaded hole 15 concentric with the mounting hole 7 is formed in the resin block portion 13 in a penetrating manner. This screw hole 15 is formed by machining, but in some cases, when filling the synthetic resin 10, a male screw may be made to protrude into the casting space and formed by casting. Further, operating holes 16 for use with a tightening/loosening tool attached to the grinder are formed by casting at a plurality of locations on the surface of the resin block portion 13 in the circumferential direction.

In FIG. 3, a screw shaft 19 is provided protruding from the lower part of the drive shaft 18 of the grinder. After inserting the collar 20 into the screw shaft 19, the resin block portion 13 is screwed into the screw hole 15 to attach the board 2. At this time, when the substrate 2 is grasped and twisted by hand, the resin block portion 13 is firmly screwed into the screw shaft 19, so that the rotary grinding and polishing tool 1 can be attached to the drive shaft 18 without using a tightening/loosening tool. It can be carried out. The relationship between the rotation direction of the drive shaft 18 and the screw direction of the screw hole 15 and the screw shaft 19 is such that the screw hole 15 tightens on the screw shaft 19 due to the grinding reaction force that the board 2 receives during use. Set it to spiral.

Note that the board 2 can be attached to and detached from the drive shaft 18 by operating the operation hole 16 with a tightening/loosening tool, but such attachment/detachment operation is performed using the screw shaft 19 of the screw hole 15.
Normally, the board 2 can be attached and detached by directly twisting the board 2 by hand only when the screwing strength is extremely high.

(Modified Embodiment) It is also possible to provide a recess or a protrusion on the inner surface of the offset recess 12 at the time of forming the substrate to improve the adhesive strength of the resin block portion 13 to the substrate 2. For the same purpose, a protrusion may be cut and formed on the base 8.

Further, the substrate 2 may be made of a plastic molded product.

(Effects of the invention) As explained above, the rotary grinding and polishing tool of the present invention utilizes a thermosetting synthetic resin with self-adhesive properties to bond the coated abrasive paper to the substrate. The resin block was filled into the offset recess so as to be substantially flush with the adhesive layer, and a screw hole for screwing into the grinder drive shaft was formed in the center of the resin block. Therefore, torque can be transmitted over the entire surface of the board that is bonded to the synthetic resin, reducing the load per unit area compared to conventional grindstones, and transmitting a large overall driving torque to the board. Summer. This makes it possible to rotate the rotary grinding and polishing tool at a higher speed or with a larger diameter, allowing efficient grinding or polishing work.

In addition, by pouring the synthetic resin onto the substrate and forming and curing the resin block part at the same time as the adhesive layer, the resin block part can be integrated with the board, so the member corresponding to the resin block part can be formed in advance. In addition to improving the adhesive strength compared to the case where the tool is first integrated with the substrate, the fixing process can be omitted, and the manufacturing cost of the rotary grinding and polishing tool can be reduced as a whole. Further, since a screw hole is formed in the resin block provided in the offset recess, a sufficient length can be ensured for the screw hole, and the threaded connection with the grinder drive shaft can be reliably performed.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of this invention, with Figure 1 being a longitudinal cross-sectional view of the rotary grinding and polishing tool, Figure 2 being a vertical cross-sectional view of the tool in the middle of formation, and Figure 3 showing the drive shaft. FIG. 3 is a vertical cross-sectional view of the installed state. FIG. 4 is a longitudinal sectional view of a conventional grindstone in a separated state. 2... Board, 3... Abrasive cloth paper, 7... Mounting hole,
10...Synthetic resin, 12...Offset recess, 1
3...Resin block part, 15...Screw hole, 18...
...Drive shaft, 19...Screw shaft.

Claims (1)

[Claims for Utility Model Registration] A plurality of coated abrasive papers 3 are arranged radially on the surface of a circular substrate 2 having a mounting hole 7 in the center, and the back side of each coated abrasive paper 3 is attached to the abrasive cloth on the rear side in the direction of rotation of the whetstone. A rotary grinding and polishing tool formed by partially polymerizing paper 3 and arranging it circumferentially on the polishing surface of the paper 3 and bonding them together via an adhesive layer made of a thermosetting synthetic resin 10 having self-adhesive properties. The substrate 2 is formed in an offset shape in which the portion around the mounting hole 7 is offset toward the back side from the adhesive portion of the coated abrasive paper, and the offset recess 12 formed by the offset of the substrate has an offset shape. The thermosetting synthetic resin 10 is filled into the offset recess 12 so as to be substantially flush with the adhesive layer, and a truncated conical resin block part 13 continuous with the adhesive layer is integrally provided. Rotary grinding and polishing characterized in that a screw hole 15 is bored in the center of the resin block part 13 and is concentric with the mounting hole 7, which can be screwed into the screw shaft 19 of the drive shaft 18 of the grinder. Ingredients.