JPH0755410B2 - Ball end mill manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a ball end mill in which polycrystalline diamond is used for a cutting edge portion.

[0002]

2. Description of the Related Art Generally, this type of ball end mill is
As shown in FIG. 8, a shank 1 made of cemented carbide is subjected to processing such as groove formation, and then a diamond cutting blade 2 is attached and fixed to its tip. Then, to give an example of a specific size, the total length L is 100 to 200 mm, the effective cutting edge length 1 is 30 to 55 mm, and the diameter D of the cutting edge is 5-1.
2. The tip R of the diamond cutting edge 2 is set to 2.5 to 6.0 mm, and the axial length of the diamond cutting edge 2 is set to about R + 2 mm. In manufacturing a ball end mill having such a shape, a shank 1 portion is formed of cemented carbide and a diamond cutting edge 2 having a predetermined shape is formed, and the diamond cutting edge 2 and the shank 1 are brazed. Are integrated by.

With such a ball end mill, when machining aluminum, graphite, etc., the tool life is about 10 times longer than that of a cemented carbide tool, good sharpness improves the accuracy of the finished surface, and the shank portion Since is a cemented carbide, it has an excellent effect that it can be processed with high rigidity and high precision.

[0004]

However, in manufacturing a conventional ball end mill, the diamond cutting edge 2 and the shank 1 have to be integrated by brazing as described above, so the minimum diameter is limited to about 5 mm. However, it is not possible to manufacture ball end mills with smaller diameters. However, there is a demand for a ball end mill having a cutting edge portion having a smaller diameter at present, which requires machining of a fine portion, and the emergence of such a ball end mill is awaited.

[0005]

Means for Solving the Problems A diamond material having a diamond layer formed on one surface of a substrate is provided, and a diamond chip having a circular cross section is cut out and formed with an axis inclined at a predetermined angle with the surface of the diamond material. The tip was fixed to the shank by brazing, and the tip of the diamond tip was processed into a desired shape.

[0006]

[Function] Since the diamond tip is cut and formed with an axis centered at a predetermined angle with respect to the surface of the diamond material, its diameter can be made extremely small, and a ball end mill with a small cutting edge portion can be obtained, and
It is easy to manufacture, and since the shank portion is made of cemented carbide and its diameter can be increased, it has high rigidity and can be machined with high precision.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. A ball end mill as a final product is shown in FIG. 7, and a process for obtaining the product will be sequentially described. Although dimensions are used in the following description, the dimensions themselves are examples, and are for the purpose of assisting the understanding of the manufacturing method by the specific size as a tool.

First, a diamond material 5 is formed by laminating a diamond layer 4 having a thickness of 1.5 mm on one surface of a base material 3 formed of a material such as tungsten carbide in a disk shape. The diamond material 5 has a total thickness of 8.0 mm and a diameter of 50.8 mm. The diamond material 5 is attached to the wire electric discharge machine, but the diamond layer 4 is attached to the wire 45
Set in a tilted state. Then, the diamond tip 6 having a diameter of 3.5 mm is cut out in a state of being inclined with respect to the surface of the diamond layer 4 by the wire, that is, in a state of being inclined by 45 degrees. Such a diamond tip 6
Are continuously cut out over the front surface of the diamond material 5, and the diamond layer 4 forms a polycrystalline diamond portion 7. Then, as shown in FIG. 2, the end portion of the diamond tip 6 on the side opposite to the side where the polycrystalline diamond portion 4 is present is cut into a V shape at an angle of 90 degrees to form a joint surface 8. The length from the end of the joint surface 8 to the tip of the polycrystalline diamond part 4 is 12.6 mm.

On the other hand, the cemented carbide material forms the shank 9 as shown in FIG. This shank 9
Its diameter is 4.0 mm and its total length is 71.5 mm.
Then, the tip of the shank 9 is processed into a taper with a slope of 7 degrees and 30 minutes on one side within a length of 3.8 mm, and the joining surface 8 formed on the diamond tip 6 is formed at the end. The concave V-shaped joint surface 10 is formed so as to be perfectly joined.

Then, as shown in FIG. 4, the preformed shank 9 and the diamond tip 6 are integrated by brazing with their joint surfaces 8 and 10 aligned with each other. At that time, their axes coincide. Then, the diamond tip 6 is polished so that the outer peripheral dimension is 3.0 mm.

Further, as shown in FIG. 5, the polycrystal diamond portion 7 at the tip portion of the diamond tip 6 is machined to the back 11 of the blade by wire discharge. That is, only one side of the tip of the diamond tip 6 is cut.

Next, as shown in FIG. 6, a groove 12 having a groove angle of 130 degrees and a depth of 0.8 mm is formed by grooving and polishing. When processed in this way, the total length is 82.
It is 5 mm.

Then, finally, the product is completed by finishing the processing shown in FIG. That is, the R portion 13 of 1.5R is formed at the tip of the polycrystalline diamond portion 7 and
The angle of 5 degrees and 35 degrees is compounded, and it is 15 in the radial direction.
To form the relief portion 14 by combining the angle of 40 degrees and 40 degrees,
Further, a working with a blade for forming the blade 15 of 45 degrees is performed. In this way, a ball end mill having a small diameter is manufactured. The total length of this completed ball end mill is 8
It is 0 mm.

In the above embodiment, the tip portion having a diameter of 3.0 mm has been described, but it goes without saying that it is possible to manufacture a ball end mill having a diamond tip 6 having a smaller diameter. .

[0015]

As described above, the present invention provides a diamond material having a diamond layer formed on one surface of a substrate, and cuts and forms a diamond chip having a circular cross section with an axis centered at a predetermined angle with the surface of the diamond material. Then, the diamond tip was fixed to the shank by brazing, and the tip of the diamond tip was processed into a desired shape, so that the diamond tip is cut out with an axis centered at a predetermined angle with respect to the surface of the diamond material. The diameter can be made extremely small, and a ball end mill with a small diameter cutting edge can be obtained, and
It is easy to manufacture, and since the shank portion is made of cemented carbide and its diameter can be increased, it has effects such as high rigidity and accurate machining.

[Brief description of drawings]

FIG. 1 shows an inclined diamond material, (a) is a plan view and (b) is a side view.

FIG. 2 shows a diamond tip, (a) is a plan view,
(b) is a side view.

FIG. 3 shows a shank, (a) is a plan view and (b) is a side view.

4A and 4B show a state in which a shank and a diamond tip are combined, FIG. 4A being a plan view and FIG. 4B being a side view.

FIG. 5 shows a state in which the back of the blade at the tip of the diamond tip is processed, (a) is a plan view, and (b) is a side view.

FIG. 6 shows a state in which a groove is formed in a diamond tip portion, (a) is a side view and (b) is a front view.

FIG. 7 shows a completed ball end mill, (a) is a plan view, (b) is a side view, (c) is a front view, and (d) is a perspective view.

FIG. 8 is a side view of a ball end mill showing a conventional example.

[Explanation of symbols]

 3 Base material 4 Diamond layer 5 Diamond material 6 Diamond tip 9 Shank

Claims (1)

[Claims] 1. A diamond material having a diamond layer formed on one surface of a substrate, a diamond chip having a circular cross section is cut out with an axis inclined at a predetermined angle with respect to the surface of the diamond material, and the diamond chip is shank. A method for manufacturing a ball end mill, which comprises fixing by brazing and processing the tip of the diamond tip into a desired shape.