JPH0321895Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a drill for plate glass that eliminates uneven wear of the abrasive layer and extends the life of the drill.

A conventional plate glass drill will be explained. FIGS. 4a and 4b are vertical cross-sectional views showing various conventional holes drilled in a plate glass 41, and the hole 42 is shown in FIG. 5a.
and the hole 43 is drilled by a drill as shown in FIG. 5b.

The drill 51 includes a cylindrical body part 52 and a swollen diameter part 5 having a substantially conical surface on the lower surface, which is fixed around the tip of the cylindrical body part 52.
3, and has an abrasive material layer 54 at the lower end of the cylindrical body part 52 in the figure and at the conical surface of the enlarged diameter part, respectively. The other drill 55 has a generally inverted conical portion 5 at its lower end.
6, and the peripheral surface of the inverted conical portion 56 also has an abrasive layer 54 in the same manner as described above. When the drills 51 and 55 having such a structure are rotated and pressed against one surface of the glass plate 41, holes 42 and 43 as shown in FIGS. will be formed.

Incidentally, the abrasive layer 54 is formed by bonding diamond particles or the like with a binder, and is formed of uniform diamond particles or the like. Therefore, use drills 51 and 55 to drill hole 4.
2 and 43, the abrasive material layer 54 provided on the conical surface portion of the enlarged diameter portion 53 and the abrasive material layer 54 of the inverted conical portion 56 are divided into a portion involved in long-term grinding and a portion involved in short-time grinding. This results in uneven wear. As a result, as the drilling work is repeated, the shapes of the holes 42 and 43 are distorted, and the life of the drill itself is also shortened.

Further, the hole 44 shown in FIG. 4c is a hole formed with two different diameters, and a drill for drilling such a hole is not commercially available. Even in a drill that drills such a hole 44, especially the enlarged diameter part 4
In the abrasive material layer for grinding 5, even if the grinding time is the same, the amount of movement is different, so there is an overall difference in the amount of grinding, and there is a problem that uneven wear occurs.

The inventor of the present invention has devised the present invention in view of the above-mentioned problems regarding plate glass drills and to effectively solve the problems.

The purpose of this invention is to prevent uneven wear on the abrasive layer and extend the life of the drill.
Another object of the present invention is to provide a drill for plate glass that is intended to form a hole without changing the shape of the hole to be drilled.

A feature of the present invention is that in a drill that has a swollen diameter section at the tip and processes plate glass using the swollen section, a tapered surface or a surface perpendicular to the drill axis is formed at the tip of the swollen section, and the tapered surface is In the case of a surface perpendicular to the drill axis, the particle size of the abrasive particles is gradually increased in the radial direction and the density of the abrasive particles is gradually increased in the radial direction. This is due to the fact that it was configured to do so.

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view of a drill for plate glass according to the present invention, and FIG. 2 is an enlarged view of the main parts thereof.

In FIG. 1, 1 is a cylindrical body, and the cylindrical body 1
At the tip thereof, a swollen diameter portion 2 having a surface 2a similar to a conical surface on the lower surface side is spaced apart from the tip by a certain distance.
is fixed with screws etc. Abrasive material layers 3 and 4 are provided on the tip of the cylindrical body portion 1 and the surface 2a of the expanded diameter portion 2, and in this way, a plate glass drill is constructed. This drill is for drilling the hole 42 described above.

In the above, the abrasive material layer 4 is formed by bonding abrasive particles such as diamond particles with a binder. Specifically, depending on the properties of the workpiece, an alloy such as renin may be used as a binder, or sintering means may be used. In the present invention, as shown in FIG. 2, the abrasive material layer 4 is formed such that the particle size of the abrasive particles 5 is large at the center and gradually becomes smaller toward the periphery. The particle size of the abrasive particles 5 varies slightly depending on the hole to be drilled, but is used in the range of 40 to 200 mesh, and the abrasive layer 4 is formed as described above according to the particle size within this range. do.

The abrasive layer 4 is also formed such that the density of the abrasive particles 5 is large at the center and becomes smaller toward the periphery.

According to the above, during grinding, since the grain size of the abrasive particles 5 in the center of the abrasive material layer 4 where the amount of grinding is large is made larger than that in the peripheral part, the wear in the abrasive material layer 4 is made uniform and uneven wear is prevented. It never happens.
Therefore, the drilling work can be carried out for a long time and the shape of the hole will not be deformed.

FIG. 3 shows a longitudinal cross-sectional view of a plate glass drill according to another embodiment, and the purpose of this drill is to drill the hole 44. The drill 6 consists of a rotatable cylindrical body part 7 and a swollen diameter part 8 fixed thereto, and this swollen diameter part 8 is formed into a thick cylindrical shape. Abrasive material layers 9 and 10 are provided on the lower surface 10a, which is a surface perpendicular to the tip of the cylindrical body portion 7 and the drill axis. The abrasive layers 9 and 10 are formed by bonding abrasive particles with a binder as described above.

In such a drill, since the amount of grinding is larger in the peripheral part of the abrasive layer 10 than in the central part,
The abrasive layer 10 is formed such that the particle size of the abrasive particles is increased in the peripheral area and becomes smaller toward the center.
Further, the density of the grinding particles is also formed so that the density is large at the periphery and becomes smaller toward the center.

As described above, in the drill 6, since the amount of grinding in the peripheral portion is increased, the abrasion of the abrasive layer 10 is made uniform, the life of the drill is extended, and a well-shaped hole can be formed over a long period of time.

As is clear from the above explanation, according to the present invention,
In plate glass drills, the larger the grinding amount of the abrasive material is, the larger the grain size of the abrasive particles and the higher the density, which equalizes the wear of the abrasive material and extends the life of the drill. It exhibits the effect of making holes.

[Brief explanation of the drawing]

The drawings illustrate one embodiment of the present invention, FIG. 1 is a longitudinal cross-sectional view of a drill for plate glass according to the first embodiment, FIG. 2 is an enlarged view of the main part, and FIG. 3 is a diagram according to the second embodiment. FIG. 4 is a longitudinal sectional view of a drill for plate glass, FIG. 4 is a sectional view showing the shape of a hole in a plate glass, and FIG. 5 is a longitudinal sectional view of a conventional drill for plate glass. In the drawings, 1 and 7 are cylindrical parts, 2 and 8 are expanded diameter parts, 3, 4, 9, and 10 are abrasive layers, and 5 is abrasive particles.

Claims (1)

[Claims for Utility Model Registration] A drill using grinding particles that has a swollen diameter section at the tip and processes plate glass using the swollen section, the tip of the swollen section having a tapered surface or a surface perpendicular to the drill axis. A drill for plate glass, characterized in that the particle size and density of the grinding particles are gradually increased in the radial direction where the amount of grinding increases.