JPS6150624B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to the manufacture of root canal cutting tools such as dental reamers or K-files that can be manufactured in large quantities in a short time with good precision and uniformity. More specifically, the method involves processing a metal wire material to form a predetermined tapered prismatic material, then processing the tip of this prismatic material to form a pyramid corresponding to the prism at the tip of the prismatic material, and further The present invention relates to a method for manufacturing a root canal cutting tool, characterized in that the root canal cutting tool is manufactured by subjecting the prismatic material having a pyramid at its tip to a twisting process.

A cutting tool that has a pyramid at the tip of a dental reamer or a K-file and is made by threading a polygonal cross section over almost the entire length has conventionally been used, for example, as shown in FIGS. It is cut to length, then ground into a tapered prismatic material with a triangular or square cross section, and then threaded. After the threading is completed, the pyramid 4 at the tip is processed, and then the handle 2 is shaped. Cutting tools were manufactured by performing attachment processing, but as shown in Fig. 2A and B, the tip surface 3 of the twisted prism has a diagonal length of 0.1 to 1.0 mm.
(length of one side is 0.07 to 0.7 mm) and is twisted, so the tip is ground to form a square pyramid 4 or a triangular pyramid (not shown) corresponding to a prism at the tip. It was extremely difficult to do so.

If the conventional method as described above is carried out, the third
As shown in Figures A to D, the pyramids 4 have irregular face sizes, the pyramids 4 have misaligned face angles and are misaligned, the ridges of the twisted column and the pyramid 4 do not match, and the pyramids 4. There are a number of defective products such as those with twisted pillars that are not perpendicular to the axis, and the grinding work requires skill, a great deal of labor and nerves, and takes a long time, and therefore has a relatively large tip diameter. 0.8mm
A skilled person could only produce about 200 bottles per hour, even for a relatively low-grade product, which had the disadvantage of not being able to be mass-produced.

The reason for the above is that it is difficult to match the pyramid 4 with the surface of the helical prism and grind it. For example, as shown in Fig. 4, it is difficult to grind the pyramid 4 to match the surface of the helical prism. It is clear how difficult this type of work is, considering that only the ivy can cause a misalignment of the sharp end and a misalignment of the bottom surface of the pyramid 4, resulting in a defective product.

I've been researching for many years to see if it's possible to use a jig or the like to accurately scrape off the material, but I couldn't find a standard for which side of the twisted object to use as a reference. In addition, since the angle of twist is slightly different, even if you use the surface of the part from the constant dimension source as a reference, it is impossible to match the surface of the prism and the pyramid 4, and it is difficult to determine the standard in the first place. It was hot. Then, it is possible to stop twisting just before the tip of the prism and create a pyramid 4 at the tip using this untwisted prism part as a reference, but this is done by extending the untwisted prism part as a reference to a certain length. Therefore, when this method was implemented, there was a risk that a completely untwisted portion would occur at the tip of the prismatic portion. If a cutting tool with no twist is used at the tip, the chips generated when cutting the root canal wall tissue cannot be completely removed to the outside by this cutting tool, and therefore a large amount of bacteria There was a problem that chips, which may contain . The method according to the present invention is a completely new technology developed in view of these drawbacks of the conventional technology, and in particular, by adopting a specific method, it is possible to mass-produce products with extremely high precision in a short time and at low cost. This relates to a completely new technology that has made this possible.

To specifically explain one embodiment of the method of the present invention with reference to the drawings, in the present invention, as shown in FIGS. is ground into a triangular or square tapered prismatic shape, and the tip of the prismatic wire material 1 ground into the tapered prismatic shape is used, for example, in Patent No. 1152938 and Japanese Patent Publication No. 1152938 filed by the present patent applicant.
The wire material 1 having the pyramid 4 at its tip is subjected to a twisting process by grinding using the technique disclosed in Publication No. 52782, etc., to create a torsion in the prismatic portion, and then the handle 2 A cutting tool can be manufactured by performing the attachment process.

The above-mentioned twisting process has already been developed and patented by the patent applicant (Japanese Patent Application No. 1983-
No. 120268) technology, in which a chuck that grips the base of the wire material and a vise claw that can press each side of the wire material at the same point in the length direction are rotated relative to each other, using a twisting device or the like. During twisting, the twisting process is stopped just before the torsion claw hits the pyramid 4 of the wire material 1, and the chuck gripping the base of the wire material is released, and then the claw is released. The pyramid 4 at the tip can be screwed almost completely to the tip without damaging it.

As described above, the method according to the present invention performs pyramidal processing on the tip of the wire material that has been ground into a tapered prismatic material without twisting it, so the pyramidal processing is performed using the prismatic body as a reference. Therefore, when a prismatic body is manufactured by grinding using the apparatus of Patent No. 1152938 of the present applicant, a large number of prismatic bodies are held in parallel in a constant posture,
These can be rotated at the same time and extremely accurate machining can be performed at the same time.
It is very efficient as it can hold more than one wire material with a jig and process it at the same time, increasing efficiency by more than 100 times compared to conventional methods.Furthermore, subsequent twisting and handle processing can be done in the same way as before. Since it can be carried out without any problems, it is possible to mass-produce products with extremely high precision at low cost, especially for irregular or misaligned pyramid surfaces, mismatched ridge lines between pyramids and twisted columns, and curves between pyramids and twisted columns. This has great effects, such as being able to significantly prevent the occurrence of defective products such as those where the angle is not perpendicular to the axis.

[Brief explanation of the drawing]

1 to 4 are explanatory diagrams of a conventional method and products manufactured by the method, and FIG. 5 is an explanatory diagram showing the method of the present application. 1 is a wire material, 2 is a handle, 3 is a tip end surface, and 4 is a pyramid.

Claims (1)

[Claims] 1 Process a metal wire material to form a predetermined tapered prismatic material, then process the tip of this prismatic material to form a pyramid corresponding to the prism at the tip of the prismatic material, and further have a pyramid at the tip. A method for manufacturing a root canal cutting tool, characterized in that the root canal cutting tool is manufactured by subjecting the prismatic material to a twisting process.