JPS58155174A - Grind stone usable for grinding and polishing - Google Patents

Abstract

PURPOSE:To eliminate the unsymmetrical wear of a grinding stone by bringing the grinding stone into flat contact with a work, with a grinding section on the peripheral surface of the offset section of the stone formed on a surface bent to the side of a backing material in a grinding and polishing stone with a multilayer grinding material of an offset type. CONSTITUTION:A base material 1 comprising a glass cloth or a glass mat made of a glass fiber is interposed integral between a backing material 4 of an unwoven cloth or paper and a glass cloth 2 and a grinding layer 3 to enhance the softness and flexibility of the entire grind stone utilizing the cushion property of the base material 1. In addition, a surface (d) bent to the side of the backing material 4 is provided on the grinding section (c) of the offset grind stone to bring the grinding material layer 3 of the grinding section (c) effectively into flat contact with the work. This eliminates unsymmetrical wear and reduces the grinding and polishing time in cooperation with the softness and flexibility from the base material 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grinding and polishing whetstone, and more particularly to a grinding and polishing whetstone having an offset type multilayer abrasive structure.

Conventionally, most grindstones for grinding and polishing have a single layer of abrasive grains using a backing material as a base material.

As a grindstone with improved flexibility, there is one in which a fiber network structure is interposed between the backing material and the abrasive grain layer (for example, Japanese Patent Publication No. 17981/1981).

However, in all conventional offset type grindstones, the polishing surface is flat, so during normal grinding (15 to 30° inclination), the outer peripheral edge of the flat part of the grindstone hits the cut to be ground.
This may damage the object to be ground or cause uneven wear on the grinding wheel. Also, the flexibility of the whetstone.

Due to the lack of flexibility, the surface of the grinding surface on the grinding wheel side that comes into contact with the object to be ground is small (as a result, the grinding efficiency of the grinding wheel is poor,
There was a drawback that grinding and polishing took time.

The present invention was made in view of the above-mentioned conventional defects.

The contact surface of the whetstone against the workpiece is made into a wide flat surface to eliminate uneven wear and reduce grinding and polishing time, while increasing the flexibility and flexibility of the whetstone to shorten grinding and polishing time and extend the life of the whetstone. It is intended to.

To achieve this object, the present invention has a base material made of glass cloth or glass mat made of glass fibers of appropriate length prepregged with synthetic resin, and a base material prepregged with synthetic resin provided on the surface of the base material. A glass cloth, an abrasive material layer made of an abrasive material coated with a synthetic resin provided on the surface of the glass cloth, and a backing material made of nonwoven fabric or paper provided on the back surface of the base material are integrated by press processing. This grindstone has an offset-type multi-layered abrasive material structure, and the grinding part on the outer periphery of the offset part of the grindstone is formed on a curved surface that is curved back toward the backing material, making use of the cushioning properties of the base material itself. By interposing the base material between the backing material, the glass cloth, and the abrasive material layer, flexibility and flexibility are increased, and the abrasive material layer of the grinding section is effectively brought into planar contact with the object to be ground. It was designed so that it could be done. moreover.

The abrasive layer of the grinding section is formed thicker than the abrasive layer of the offset section, thereby increasing the effective grinding section and further enhancing flexibility.

An embodiment of the present invention will be described below based on the drawings.

In FIGS. 1 to 3, A is an offset type grinding and polishing whetstone according to the present invention, a is a center hole drilled in the center of the whetstone for attachment to the grinder rotating shaft, and b is an offset portion. C is a ring-shaped grinding part extending smoothly and continuously outward from the periphery of the protrusion, and the thickness of the grinding part C is equal to the thickness of the protrusion. The thick part is formed to have a donut shape. The grinding portion C is formed into a curvature d that is bent back toward the side opposite to the grinding surface (towards the backing material 4, which will be described later), and the outer peripheral end of the curvature d forms a roundness dl.

Further, the warp d is inclined at 15 to 30° with respect to the horizontal plane, which corresponds to the angle at which a normal offset type grindstone is used. e is a multi-stage spiral groove recessed in the surface of the grinding portion C. In addition, B is a special butt that is applied to the back surface of the grinding and polishing whetstone when it is attached to the rotating shaft of the grinder.

The cross-sectional structure of the offset part and the grinding part C is as shown in detail in FIG. A woven fabric made by knitting glass fibers of an appropriate length into a cloth form, or a mat made by collecting up to 50 glass fibers in the form of a non-woven fabric, is dipped in a solution of a thermosetting resin such as a phenol resin and lightly dried. , a prepreg is made by adhering the thermosetting resin to a layer of glass cloth or glass mat so that the resin covers 50 or more layers.2 is a prepreg made by soaking a glass cloth in a thermosetting resin such as a phenolic resin. (Glass cloth prepregged with a dried synthetic resin, 6 is an abrasive layer, in which alumina or carborundum abrasive grains are coated with liquid phenol resin and powdered phenol resin is sprinkled on top.

The offset part is thinly coated with resin-coated brane, which is not sticky as it is, but hardens when pressure is applied, and the grinding part C is thickly coated.

It is made into a donut-shaped thick part. Also.

4 is a backing material that keeps the surface beautiful with nonwoven fabric or paper, and at the same time absorbs the resin that oozes out from the base material 1 side when molding and compressing with a mold to prevent it from transferring to the mold. It is made of a releasable material so that it can be easily removed from the mold.

Then, the base material 1. Glass cloth 2. Abrasive layer 3. As shown in FIG. 3, the backing material 4 includes a glass cloth 2. The abrasive layer 6 is placed one after another.

The back surface of the base material 1 is lined with a backing material 4, and after these are pressed in a mold and integrated, or simultaneously with the press processing, the material is heated and hardened so as to form a ground portion C on a warped surface d. It has a multi-layer abrasive structure.

The present invention is constructed as described above.

The first feature is that the base material 1 is made of glass cloth or glass mat made of glass fibers of appropriate length prepregged with synthetic resin as described above, and the backing material 4 of non-woven fabric or paper is
Glass cloth prepregged with synthetic resin 2. One of the features is that it is interposed between and integrated with the abrasive layer 3 coated with synthetic resin.

Utilizing the cushioning properties of the base material 1, the flexibility and flexibility of the entire grinding wheel are significantly improved compared to the conventional single-layer and two-layer grindstones, and the flexibility during grinding and polishing work is improved. Ru.

Furthermore, the grinding part C of the offset type grindstone has a flat part (1
Warped surface d that is warped in the opposite direction to the use side (ground and polished surface)
This is to prevent uneven wear etc. as described below.
It is more effective to make the outer peripheral end of the warped surface d rounded.

When grinding and polishing with a whetstone with such a structure, when working at an angle of 15° to 30' when an offset type whetstone is normally used, the grinding part C of the whetstone does not hit the object to be ground in a linear manner. First, the grinding surface is wide due to the contact as a flat surface of a constant width (despite the large amount of cutting and polishing, the grinding resistance is small due to the flexibility of the base material 1, and the wear of the grinding wheel is extremely low. In other words, it has been demonstrated that very effective grinding and polishing can be performed.

An experimental example of the grinding and polishing work is shown below.

[Experimental Example 1] A conventional offset type grindstone (single layer) and the present invention grindstone were made using a flexible grindstone with a diameter of 125 mm, a thickness of 3 mm, a hole diameter of 16-1, and an abrasive grain of AC46. 6 cabinets thick with the same pressure! The S41 material was ground and polished. The results are as follows (the grinding ratio was significantly improved).

Next, the second feature is that the abrasive material layer 6 of the grinding part C of the grinding wheel is made thick in a donut shape. It has been found that if only the outer peripheral part used for grinding and polishing is made thicker, the flexibility will be increased, the grinding and polishing time will be shorter, and the usage time (life) will be greatly extended. Here is an example of an experiment.

[Experimental Example 2] In Experimental Example 1, the thickness of the abrasive material layer in the grinding part with a radial length of 25 cm was increased by 2-2, and a grinding wheel was used (9). The results of testing the grindstone 2 of the present invention in an experiment using 11 grindstones of the present invention were as follows.

As described above, the grinding ratio was significantly improved, and from the results below, it was found that the grinding wheel 2 of the present invention was significantly better in terms of the abrasive material and maximum usage time due to the effective use of abrasive grains per piece as shown below.

Also, the radial length of the thick portion (ground portion) is as follows.

It is effective to change it according to the outer diameter of the grinding wheel.

The following combination has the longest abrasive material and usable time (
It has been proven that it can be done.

As detailed above (1) The present invention is characterized by the flexibility of the base material of glass cloth or glass mat made of glass fibers and the warped surface of the grinding part of the whetstone, so that the grinding part of the outer periphery of the whetstone has a wide contact area with a flat surface. Since it can be ground and polished, constant cutting and constant wear continue for a long time.

Grinding and polishing time can be shortened compared to the amount of wear on the grindstone, and uneven wear (deformation wear) does not occur, so almost all usable abrasive grains can be used. Because of this, the grinding wheel can be used until it loses its cutting power, resulting in unbalanced wear of the grinding wheel, which significantly extends the life of the grinding wheel.Thickening of the abrasive material layer in the grinding section improves these effects. is further encouraged.

Further, by providing a large number of spiral grooves on the outer periphery of the grindstone, the heat of grinding and polishing can be dissipated from the grooves, and the chips can also be released, which also has the effect of increasing flexibility.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the grinding and polishing whetstone of the present invention, FIG. 2 is a partial plan view, and FIG. 3 is an enlarged longitudinal cross-sectional view of the main part. A...Whetstone for grinding and polishing, B...Special bat%a...
Center hole, b Offset part, C... Grinding part, d...
Warped surface, e Spiral groove, 1... Base material, 2... Glass cloth, 3... Abrasive material layer, 4... Backing material.

Claims (1)

[Scope of Claims] +11 A base material made of glass cloth or glass mat made of glass fibers of appropriate length prepregged with synthetic resin, a glass cloth provided on the surface of the base material and prepregged with synthetic resin, An offset-type product in which an abrasive material layer made of an abrasive material coated with a synthetic resin is provided on the surface of the glass cloth, and a backing material made of nonwoven fabric or paper is provided on the back surface of the base material, which are integrated by press processing. A grinding and polishing whetstone having a multilayered abrasive material structure, characterized in that a grinding portion on the outer periphery of a grinding wheel offset portion is formed on a warped surface that is warped toward a backing material side. (2) The abrasive material layer of the grinding part is formed thicker than the abrasive material layer of the offset part.
Grinding and polishing whetstone as described in Section 1. (3) The grinding and polishing whetstone according to claim 11 or (2), wherein the warped surface is inclined by 15 to 30' with respect to the horizontal plane. (4) The grinding and polishing whetstone according to claim 1, (2), or (3), wherein a large number of spiral grooves are formed on the surface of the abrasive layer of the grinding portion. (5) The grinding and polishing whetstone according to claim 11+, (2), (3), or (4), wherein the outer peripheral edge of the abrasive material layer of the grinding portion is rounded.