JPH0671012U - Diamond coated drill - Google Patents

Abstract

(57) [Summary] [Purpose] Reuse a diamond coated drill. [Structure] A drill having a diamond coating 2 at its tip, the coating length of which is 0.3 to 1.
The length was up to 5 mm. When the drill is worn because the coating length is short, the waste of the base material can be minimized even if the remaining portion of the coating is removed together with the drill base material 1 and the diamond is coated again.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a diamond-coated drill.

[0002]

[Prior art]

 Conventionally, the tip of the drill is coated with diamond, but the diamond coating of such a drill is about 1.5 to 3 times the drill diameter from the outer peripheral corner 4 as shown in FIG. Extends to the length of the area (covered with diagonal lines). For example, with a drill having a diameter of 5 mm, the diamond is coated from the outer peripheral corner to a length of about 6 to 7 mm.

By the way, when such a drill is used, the diamond coating 2 is particularly worn on the flank 5 near the outer peripheral corners, and usually the useful life is reached here. Disposing the drill in this state is a waste of the drill base material 1, such as expensive cemented carbide. Therefore, when considering this reuse, there are two methods: a method of polishing and using the flank (repolishing) and a method of recoating the damaged portion of the coating (recoating).

[0004]

[Problems to be solved by the device]

 Re-polishing can be performed by the user and is convenient, but if the life of a new drill with a coating is 100, the re-polishing is about 60 to 70 because the flank 5 has no coating. For this reason, there was a problem that the drills had to be replaced at different times, which was not preferable for operation. On the other hand, in the case of recoating, if the diamond coating remaining on the rake face 6 and the margin 7 is not coated but is recoated, the diamond is thickened only in the remaining portion of the coating, and the drill diameter becomes large. Therefore, it is only necessary to remove the remaining coating, but it is extremely difficult to completely remove the coating applied to the base material having a complicated shape such as a drill. Further, if the remaining portion of the coating is removed together with the base material by cutting or the like, the drill groove length will be drastically shortened, and there will be a large amount of waste of the base material.

[0005]

[Means for Solving the Problems]

 In order to solve such a problem, the present invention devised a drill that can be reused by re-coating, and its feature is that in a drill with a diamond-coated tip, the coating length is 0.3 to This is because the length is 1.5 mm.

[0006]

[Action]

 In the past, since the coating length was long, the base material was wasted a lot if the remaining portion was cut and removed during regeneration. In the present invention, by limiting the diamond coating length, it is possible to minimize the waste of the base material even if the coating remaining part is removed together with the base material and diamond is coated again and reused. If the coating length is less than 0.3 mm from the outer peripheral corner, the machining performance and life will be greatly reduced compared to the conventional product (the coating length is about 1.5 to 3 times the drill diameter from the outer peripheral corner). If it exceeds 1.5 mm, the base material part to be removed during recoating is large and wasteful. Preferably, it is in the range of 0.5 to 1 mm. The specific coating length may be appropriately selected from the above range depending on the diameter of the drill.

A method of removing the remaining portion of the coating together with the base material at the time of reuse is shown below. Polish and remove from the drill tip. This is the simplest method. It is difficult to polish and remove the diamond coating in a direction substantially parallel to the coated surface, but it can be relatively easily removed by setting the polished surface in a direction intersecting the coated surface. When the remaining coating is removed, there is almost no coating on the flank due to abrasion, and the coating remains on the rake face and margin. Therefore, even if polishing is performed according to the drill tip angle, the polished surface will be in a direction intersecting with the remaining diamond coating surface, and the coating remaining on the rake face or margin will be easily removed by polishing. You can

The remaining portion of the coating is cut and removed by a wire electric discharge machine or the like. In this case, the simplest way to do this is to slice the tip of the drill and remove the remaining coating. Further, in order to maintain the tip angle R of the drill (see FIG. 1 (B)), the cutting edge may be arranged parallel to the wire electrode and the remaining portion of the coating may be removed while rotating the drill. In this case, the amount of the base material removed is smaller than in the case of the above-mentioned sliced piece, and the more effective use can be achieved.

After the remaining portion of the coating is removed by the method as described above, the drill tip shape is adjusted, and coating is performed again from the outer peripheral corner to the length of 0.3 to 1.5 mm, whereby the drill can be regenerated. Then, as long as the groove length of the drill does not hinder the use, the drill can be reused by repeating such regeneration work as many times as necessary. When removing the remaining portion, the drill tip angle can be freely changed as required.

[0010]

【Example】

 Embodiments of the present invention will be described below. Fig. 1 is a diagram for explaining the method of regenerating the drill of the present invention. (A) is a new state with a diamond coating on the tip, (B) shows the coating remaining after the drill shown in (A) is worn. The removed product, (C), is the product produced by applying the coating to (B).

(Structure) The structure shown in (A) is a drill base material 1 made of cemented carbide with a diamond coating 2 (shown by diagonal lines) having a diameter of 5 mm and a groove length of 38 mm. The coating 2 has a thickness of about 10 μm and extends not only from the chisel edge 3 to the outer peripheral corner 4 but also from the outer peripheral corner 4 to the shank side up to 0.5 mm. In such a drill, for example, the drill is inserted into a hole provided in a Si block to expose only a portion to be coated with diamond and mask other portions. Then, it can be manufactured by growing diamond by the CVD method. Here, the material of the masking block is preferably as little as possible soot is generated, and in particular, in addition to Si, which has excellent workability, cemented carbide, ceramic, Mo, W, etc. are preferable. The masking block also acts as a heat sink to prevent excessive temperature rise.

(Remanufacturing Method) When worn due to use, the coating is most severely worn on the flanks 5 and the outer peripheral corners 4, and the rake face 6, margin 7, second take-up face 8 and the like remain relatively. Therefore, first, the remaining portion of the cover is removed. In this example, the remaining portion was removed by polishing and the tip shape was adjusted. As a result, as shown in (B), the groove length was shortened by about 1 mm. Even when the same drill is sliced with a wire electric discharge machine to remove the remaining portion, the recession of the groove length can be suppressed to about 3 mm. Then, by removing the portion up to 0.5 mm from the outer peripheral corner toward the shank side and masking as described above to form the diamond coating by the CVD method, the drill can be regenerated as shown in (C). . In this way, with the coating length as in this example, the groove length recedes due to the regeneration is slight, and it can be sufficiently used even after performing the regeneration work about 10 times.

[0013]

[Test example]

 (Life test) Actual drilling was performed using the above drill. The processing conditions are as follows. Work Material: A390-T6 (Al-17% Si) Cutting Speed: V = 80m / min Feed: S = 0.1mm / rev Hole Depth: 15mm Through Cutting Oil: Water-soluble emulsion 10%

Further, as a comparative example, the diamond coating length is 1.5 times the diameter, the base material, the diameter, etc. are the same as those in the practical example (Comparative Example 1) and the cemented carbide drill without the diamond coating (Comparative Example). The same punching process was performed using 2). Then, each time the drill wears, the reproduction by polishing and the drilling process are repeated, and the life per one use (the number of holes drilled), the number of times of reproduction, the total life {1 use life × (number of times of reproduction + 1)} Examined. The results are shown in Table 1.

[0015]

[Table 1]

As shown in the table, the one-use life was 350 in Comparative Example 2 without the diamond coating, whereas the number of holes in the Comparative Example 2 was 5000 or more in the coated Example and Comparative Example 1. there were. However, in Example and Comparative Example 2, the reproduction was possible 10 times by polishing, and the total life was 55,000 or more and 3850, respectively. Therefore, the example has a total life of 10 times that of the comparative example 1. Incidentally, in Comparative Example 1, since it is generally used for one use, it was not regenerated. Even if the comparative example 1 is regenerated by polishing, the coating length is long and therefore the number of times of regeneration is about 2 times, and it is not considered that the total life is significantly extended as in the example.

(Machining Accuracy Test) Further, in the above machining, the surface roughness of the inner surface of the machined hole and the waviness in the machined hole longitudinal direction were also measured. The measured length of the surface roughness was 0.8 mm and that of the waviness was 10 mm, and two samples were used only in the examples to confirm reproducibility. 2 and 3 are graphs showing the relationship between the number of holes per use and the above measurement results. As shown in the figure, Comparative Example 2 having no diamond coating was relatively good in terms of surface roughness, but was insufficient in terms of waviness. On the other hand, the example showed almost the same results in both surface roughness and waviness as compared with the comparative example 1.

From the above life test and machining accuracy test, it is confirmed that the working example is no better than Comparative Example 1 having a long coating length, and that there is almost no deterioration in the processing performance due to the shortened coating length. Was done.

[0019]

[Effect of device]

 As described above, the diamond-coated drill can be regenerated by the drill of the present invention with the minimum amount of base material removed. In particular, since the groove length recedes a little during regeneration, it can be regenerated repeatedly and one drill base material can be effectively used. In addition, there is almost no deterioration in the machining performance due to the limited coating length, and it has the same machining performance as the conventional diamond-coated drill. Furthermore, since the drill tip angle can be changed during regeneration, the bite of the drill can be adjusted according to the work material.

[Submission date] June 16, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

As described above, the diamond-coated drill can be regenerated by the drill of the present invention with the minimum amount of the base material removed. In particular, since the groove length recedes due to regeneration is very small, the grinding work during regeneration is extremely simple and can be regenerated repeatedly, so that one drill base material can be effectively used. In addition, there is almost no deterioration in the machining performance due to the limited coating length, and it has the same machining performance as the conventional diamond-coated drill. Furthermore, since the drill tip angle can be changed during regeneration, the bite of the drill can be adjusted according to the work material.

[Brief description of drawings]

FIG. 1 is an explanatory view of a method for reproducing a drill according to the present invention,
(A) is a new state with a diamond coating on the tip, (B) is the one shown in (A) after wear of the drill and the remaining coating is removed, and (C) is a coating on (B). It has been applied and regenerated.

FIG. 2 is a graph showing the relationship between the number of holes and surface roughness.

FIG. 3 is a graph showing the relationship between the number of holes drilled and the waviness in the hole longitudinal direction.

FIG. 4 is a side view of a conventional diamond-coated drill.

[Explanation of symbols]

 1 Drill base material 2 Diamond coating 3 Chisel edge 4 Peripheral corner 5 Relief surface 6 Rake surface 7 Margin 8 Second picking surface R Tip angle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiji Nakatani 2-80 Hotorikitamachi, Sakai City, Osaka Prefecture Osaka Diamond Industrial Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A drill having a diamond-coated tip, the coating length of which is 0.3 to 1.5 from the outer peripheral corner.
A diamond-coated drill characterized by having a length up to mm.