JPH0232053B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes frictional heat and pressure by rotating at high speed along a vertical axis to form a hole having a flange around it in a metal plate or metal tube wall. a cylindrical shank for engaging a chuck;
It includes a wide shoulder and an actuating blade adjacent to the shoulder having a width that determines the hole diameter, and the actuating blade is tapered at its lower end.

A tool of this kind, called a flow-drilling tool, is disclosed in German Patent No. 2 359 794. In the known flow type drilling tool, in addition to the shank gripped by the chuck, the shoulder also has a cylindrical shape, and the operating blade adjacent to the shoulder has a triangular cross section with chamfered corners. .

A similar flow-type drilling tool is also disclosed in German Patent No. 2552665. In the tool disclosed in this patent, the main blade part does not have a triangular shape, and the cross-sectional shape of the peripheral part is determined by a plurality of overlapping circular arcs with different radii of curvature. There is.

Flow-shaped drilling tools of the type described above are manufactured from sintered carbide material, which is very difficult to machine, and their rather complex shape requires grinding from a cylindrical rod material. can't get it. Producing flow-shaped drilling tools with substantially the same shape requires advanced technology;
Grinding operations require large amounts of money.

One object of the present invention is to provide a simple and inexpensive structure;
The object of the present invention is to provide a flow-type drilling tool of the type described above. To achieve this objective, in the flow-type drilling tool according to the invention, the shoulder of the tool and the working blade are adjacent to each other across two parallel planes, and the thickness of the working blade is maximized. However, the other adjacent surface is chamfered with a radius of curvature equal to half the maximum width of the working blade, and the other adjacent surface is less than 1/2 the width of the working blade.

The thickness of the actuating blade portion is preferably one-third or less of its maximum width.

The flow-type drilling tools described above are of the self-centering type, in which at least three side edges of the tool are brought into contact with the walls of the formed hole, so that the shape of the tool is primarily triangular in cross-section. It is. However, the anticipated difficulties with centering can be overcome by using a flat-cone-shaped drilling tool. Therefore, in manufacturing a flow-type drilling tool, it is possible to use a piece of sintered carbide material and grind and chamfer only the side edges and the bottom edge of the shoulder. This makes it possible to significantly reduce material and machining costs. the result,
Cost savings of approximately 30% can be achieved. This flat-conical drilling tool can be secured in a suitable manner to the cylindrical shank so that the tool can be gripped by a rotary chuck.

A flow-shaped drilling tool with flat sides is known as such from French Patent No. 1 189 384;
Such prior art flow-type drilling tools include:
There is no shoulder section. The working blade of the drilling tool has a rectangular cross-section, the length of its diagonal is equal to the diameter of the hole to be formed, and the four corners are in contact with the walls of the hole to be formed, so that the tool It is not a flat-cone drilling tool in the sense of the present invention.

The advantages obtained with the flat conical flow drilling tool are further enhanced by manufacturing the tool from two different materials. In this case, the bottom edge of the mandrel shoulder and the side edges of the actuating blade are preferably constructed of sintered carbide metal strips of different materials bonded together in a T-shape. This margin piece of sintered carbide metal may be connected to the plane of the T-shaped mandrel body, for example by soldering, or by adhesive to the side and bottom edges of a mandrel body of different material. May be connected.

The carbide pieces on the side edges of the mandrel body are
It may also be formed by vapor deposition. In this case, the mandrel body is coated with carbide not only on the side edges but also on the entire surface.

When forming larger diameter holes, for example holes with a diameter of 15 mm or more, in order to increase rigidity, the shoulder part and the actuating blade part are arranged in a radial direction and each divided along the center line. It should be formed by three interconnected mandrel body members in the shape of a knife edge, with sintered carbide margin pieces affixed to the side and bottom edges thereof.

The cone-shaped flow drilling tool may furthermore be provided with a groove, instead of a shoulder, which has the same width as the adjacent cutting edge. According to the drilling tool having such a shape, it is possible to drill a hole and simultaneously form a thread in the hole in one operation.

Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a cylindrical shank 2 and the shank 2.
1 shows a conical flow-shaped drilling tool 1 with a T-shaped mandrel body 3 or mandrel body fixed to the body. The main body 3 has a wide shoulder 4 and an adjacent working blade 5, the lower end 6 of which is tapered. With the exception of the shank 2, the body 3 may be made of carbide metal. In the embodiment of FIG. 1, the material of the body 3 only needs to have sufficient rigidity; the bottom edge of the shoulder 4 is provided with a carbide piece 8; A carbide piece 7 is provided. The substantially central portion of the carbide piece 7 needs to be bent so as to follow the chamfered end of the main body 3. Carbide piece 7
may be attached to the main body 3 in the illustrated shape. These carbide pieces 7 and 8 may be ground to have a desired radius when attached to the bottom edge and side edge of the main body 3.

Further, the carbide pieces 7 and 8 may be fixed to the bottom edge and side edges of the main body 3 by adhesive. FIG. 2 shows an adhesive layer 12 provided between the carbide strip 7 and the actuating blade 5.

The carbide piece 7 can also be fixed to the actuating blade 5 by further means as shown in FIG. In the embodiment shown in FIG. 3, a flat carbide piece 7' is soldered to the flat surface of the actuating blade 5, but in this case solder is used to make the solder joint resistant to high temperatures. It is necessary to adopt an attachment method.

FIG. 4 shows yet another method of securing the carbide piece 7' to the working blade 5'. The side edge of the working blade 5' is provided with a forked end 9 in which a carbide piece 7' is fixed.

The drilling tool described above is suitable for producing holes with a diameter of up to about 15 mm in materials with a tensile strength of up to 120 Kg/mm ² . If larger hole diameters are desired or the material is very hard, the drilling tool must be more rigid. In such a case, the half-T-shaped main body 10 (FIG. 6)
A high stiffness can be obtained by interconnecting along the side edges to form a star-shaped mandrel body and attaching carbide strips to the side ends in the manner described above.

The carbide piece provided on the bottom edge of the shoulder 4 is
As disclosed in German Patent No. 2802229, a notch may be provided in the flange formed around the hole.

Instead of fixing the prefabricated carbide pieces 7 and 8 shown in Figs. 1 to 4 to blades made of different materials, vaporized carbide is deposited on the carrier 5'' using a CVD method (chemical vapor deposition). The entire surface of the carrier 5'' is coated with the carbide layer 11, but in order to obtain an appropriate shape as a drilling tool, only the side edges that constitute the working blade portion need to be ground. good.

The shouldered flow-type drilling tool also serves to smooth the upper surface of the collar formed around the drilled hole so that it acts as a sealing surface. Then, in a second operation, a thread is cut into the hole by cutting or rolling. A flat conical flow drilling tool allows a hole to be formed and a thread to be cut in the hole at the same time in one operation. In this case, it is necessary to remove the shoulder from the drilling tool, but
This is because the work of smoothing the upper surface of the flange formed around the hole cannot be performed at the same time as the work of cutting threads.

FIG. 8 shows a flow-shaped drilling tool of the type described above. A conical main body 3 having a tapered lower end is fixed to the shank 2 . The carbide strip 7 is secured to the body 3 by any of the methods shown with respect to FIGS. 1-4. It is also possible to use the embodiment shown in FIG. The upper part of the carbide piece 7 is provided with a groove 13 for rolling a thread by grinding. The portion 12 adjacent the groove 13 is slightly tapered downwardly, preferably at an angle of about 3°. This is to facilitate the rolling operation of the thread after the hole is formed. Even if the drilling tool is not provided with the groove 13, if the operating blade is tapered at an angle of 3 degrees, the mandrel body can be easily removed from the hole.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a flat conical flow type drilling tool according to the present invention. FIG. 2 is a sectional view taken along the line -- in FIG. FIGS. 3 and 4 are cross-sectional views similar to FIG. 2, each showing another method of securing the abutment piece to the actuating portion. FIG. 5 is a cross-sectional view similar to FIG. 2, showing the operating blade portion whose surface is coated with carbide by vapor deposition. FIG. 6 is a perspective view showing an embodiment having a star-shaped operating blade. FIG. 7 is a sectional view taken along the line -- in FIG. 6. FIG. 8 is a front view of a flat conical flow type drilling tool which also performs thread rolling operations. 2... Shyank, 3... Mandrel body, 4...
...shoulder part, 5...operating blade part.

Claims (1)

[Claims] 1. A flow-type drilling tool that rotates at high speed along a vertical axis and forms a hole with a flange around the wall of a metal plate or metal tube using frictional heat and pressure, which has a chuck and an engaging cylindrical shank, a wide shoulder, a sintered carbide material provided adjacent to the shoulder, having a width that determines the diameter of the hole, and tapered at the lower end. The thickness of the working blade is equal to 1/2 of the maximum width of the working blade at its widest point, and the thickness of the working blade is equal to 1/2 of the maximum width of the working blade, and A flow type drilling tool, wherein the side edge surface is chamfered with a radius of curvature smaller than the width of the operating blade. 2 The thickness of the operating blade is 1/3 of the maximum width of the operating blade.
A flow-type drilling tool according to claim 1, which is as follows. 3. A cylindrical shank that engages with the chuck, a wide shoulder, and an operating blade that is provided adjacent to the shoulder and has a width that determines the hole diameter of the hole and has a tapered lower end. and the shoulder and the working blade are adjacent by two parallel planes, and the working blade has a maximum thickness of 1/3 of the maximum width of the working blade. A drilling tool characterized in that the bottom edge of the shoulder and the side edges of the actuating blade are constituted by a piece of sintered carbide fixed to a T-shaped blade of a different material. Flow type drilling tool. 4 The sintered carbide piece is soldered to T.
4. A flow-shaped drilling tool according to claim 3, which is connected to a flat wall of the glyph-shaped blade. 5. A flow-through drilling tool according to claim 3, wherein the sintered carbide pieces are connected to the side and bottom edges of the T-shaped blade by adhesive. 6. The shoulder and actuating blades include three interconnected blade members arranged in a star pattern, each having a T-shaped blade shape split along the centerline, with a sintered carbide piece. 3. A flow-type drilling tool according to claim 3, wherein the flow-type drilling tool is fixed to its side edges and bottom edge.