JP3134060U - Combined multi-stage drill blank for cutting tool for printed wiring board - Google Patents

Abstract

To provide a composite multi-stage drill blank for a printed wiring board capable of reducing the consumption of expensive tungsten steel material while enabling perfect round polishing of the drill blank.
A drill blank includes a welded portion made of tungsten steel material and a base material portion made of stainless steel, and one end portion of the welded portion is fixed to a central portion of one end portion of the base material portion by a welding method. The diameter and length are less than the diameter and length of the substrate portion.
[Selection] Figure 3

Description

  The present invention relates to a combined multi-stage drill blank for a printed wiring board cutting tool used in a drill bit for a printed wiring board.

The drilling process is quite popular in the processing and production of printed wiring boards.
In a conventional drilling method, a drill bit that rotates at high speed is used to drill a via hole in a printed wiring board for circuit conduction between multilayer boards or insertion of pin terminals of electronic elements.
Since the accuracy of the via hole is related to the quality of the printed wiring board, the quality of the drill bit is important.

A conventional drill blank of a printed wiring board drill bit will be described with reference to FIG.
This type of conventional drill blank combines a single-stage stainless steel base (70) and a single-stage tungsten steel weld (80), but the price of tungsten steel is more expensive than stainless steel. Therefore, considering the price of the drill bit, the length of the base material portion (70) is longer than that of the welded portion (80).
The base material portion (70) is sandwiched by the chuck portion of the subsequent drill machine, and the welded portion (80) described in the processing described later is for drilling a via hole on the printed wiring board.
And the diameter of a base material part (70) is the same diameter as the diameter of a welding part (80).

Since the one end part of the base material part (70) is welded and fixed to the one end part of the weld part (80), the welding surface (71) is provided between the base material part (70) and the weld part (80). Is formed.
The finished product is usually called a drill blank.
Then, the drill blank, which has been welded and fixed, is placed on the machine pedestal, whereby the base material part (70) and the welded part (80) are polished as a round bar with a grinder to correct eccentricity. Yes.

As shown in FIG. 9, the drill blank that has been polished is subjected to subsequent processing, which is a step of forming a tapered portion (81) and a cutting portion (82) in the welded portion (80).
The cut portion (82) is formed in the welded portion (80) to complete the production of the printed circuit board drill bit.

  In the above-described conventional drill blank, the base material portion (70) and the welded portion (80) of the drill blank have the same diameter, and a combination of different materials of stainless steel and tungsten steel each having a large difference in hardness. However, there was a drawback that the appearance had to be polished with a specific grinder suitable for each hardness.

When the base part (70) and the welded part (80) having the same drill blank diameter and different hardness are subjected to eccentricity correction by the subsequent grinder, the grinder uses a grinder to polish materials having different hardnesses simultaneously. Polishing is difficult, and problems such as occurrence of eccentricity and low roundness after polishing occur.
Such a drill blank adversely affects the quality of the subsequent drill bit forming process.

  Moreover, since the base part (70) and the welded part (80) have the same diameter, when the cutting part (82) is manufactured in the subsequent welded part (80) with a drill blank, Most of the material of the weld (80) is shaved. Therefore, depending on the manufacturer, expensive materials and processing time are wasted, and the effect of high cost is extremely large.

  The present invention has been made in view of the drawbacks of the conventional drill blank described above. The purpose of the present invention is to greatly reduce the polishing time while contributing to the perfect circular polishing of the drill blank. An object of the present invention is to provide a composite multi-stage drill blank for a printed wiring board which can reduce the consumption of expensive tungsten steel material in subsequent production.

In order to achieve the object of the above invention, in the present invention, the drill blank is composed of a welded portion of tungsten steel material and a base material portion of stainless steel material, and one end portion of the welded portion is connected to one end portion of the base material portion by welding method. The present invention provides a composite multistage drill blank of a cutting tool for a printed wiring board, which is fixed at a central portion.
That is, the first device of the present application is a composite multi-stage drill blank of a printed wiring board cutting tool comprising a welded portion of tungsten steel material and a base material portion of stainless steel material, and one end portion of the welded portion is It is fixed to the central part of the one end of the base material by a welding method, and the diameter and length of the weld is less than the diameter and length of the base, and between the base and the weld Provided is a composite multistage drill blank for a printed wiring board cutting tool, wherein a weld surface is formed.
The second invention of the present application is a composite multistage multi-stage cutting tool for printed wiring boards according to the first invention, wherein the diameter ratio of the welded portion to the base material portion is 1/5 to 3/5. Shaped drill blank.
The third device of the present application is characterized in that the length ratio between the welded portion and the base material portion is 1/10 to 1/2, and the printed wiring board cutting according to the first device or the second device is described above. A multi-stage drill blank of a composite tool is provided.
A fourth invention of the present application is a composite multi-stage drill blank for a printed circuit board cutting tool according to the first or third invention, characterized in that the cross section of the welded portion and the base material is a perfect circle. I will provide a.
The fifth plan of the present application is a composite of the cutting tool for printed wiring board according to the first or third device, wherein the cross section of the welded portion and the base material is a shape that approximates a perfect circle. A multi-stage drill blank is provided.
A sixth plan of the present application is characterized in that a taper portion is formed at a joint portion between the base material portion and the welded portion, and the multi-stage type of printed wiring board cutting tool according to the first device described above Provide drill blanks.
A seventh plan of the present application is characterized in that a connecting part having the same diameter as the welded part is formed between the tapered part and the welded part. A composite multi-stage drill blank is provided.
In the eighth plan of the present application, a taper portion is formed at the joint portion between the base material portion and the weld portion, and this taper portion is welded and fixed to an end surface portion away from the base material portion. The composite multi-stage drill blank of the cutting tool for printed wiring boards according to the first aspect, wherein a weld surface having a cross-sectional dimension larger than the diameter of the welded portion is formed. provide.

In the present invention, the diameter and length of the welded part is less than the diameter and length of the base part, and the grinder is used for subsequent round grinding of the drill blank due to the difference in the diameter ratio between the welded part and the base part. Only polishes the corresponding material.
That is, by polishing only the welded portion or the base material portion, the degree of roundness of the drill blank can be determined and the difficulty of polishing can be reduced, and the polished drill blank can have high roundness.
That is, each cross section of the welded part or the base material part can be polished into a perfect circle of 1 μm or less.

  Furthermore, because the welded part is smaller in both diameter and length than the base part, consumption of expensive tungsten steel material is reduced, material waste during production can be reduced, and cost can be reduced. It is economical.

  FIG. 1 shows an example of a composite multi-stage drill blank of a printed wiring board cutting tool according to the present invention.

  The drill blank is made of a stainless steel material and a straight rod-shaped base portion (10) having an appropriate diameter and length, and a tungsten steel material and a straight rod-shaped weld portion (20) having an appropriate diameter and length. The diameter and length of the welded part (20) are both less than the diameter and length of the base part (10).

  The center part of the one end part of the base material part (10) and the one end part of the weld part (20) are welded to each other, and a welding surface (11) is provided between the base material part (10) and the weld part (20). A drill blank is formed by the base part (10) and the welded part (20) which are formed and welded and fixed to each other.

  The diameter ratio of the welded part (20) to the base part (10) is 1/5 to 3/5, and the length ratio of the welded part (20) to the base part (10) is 1/10 to 10/10. 1/2.

In the drill blank described above, the diameter and length of the welded portion (20) are less than the diameter and length of the base portion (10), and when the drill blank is polished in the machine, the welded portion (20) and the base Since the diameter difference of the material part (10) is very large, the grinder only contacts one material and polishes the corresponding material, so only one of the welded part (20) or the base material part (10) is obtained. To polish.
Therefore, the grinder that polishes the welded part (20) does not polish the base part (10), or the grinder that polishes the base part (10) does not polish the welded part (20). As a result, each cross section of the drill blank (both the welded part (20) and the base part (10)) can be polished into a perfect circle or a shape close to a perfect circle.
This simplifies the polishing of the drill blank, and the welded part (20) and the base part (10) have high roundness.

  FIG. 2 shows a process of manufacturing a drill bit for a printed wiring board by subsequent processing in the drill blank of the present invention.

The taper portion (12) is formed at the end of the base material portion (10) at the joint portion of the base material portion (10) and the welded portion (20) with the polished drill blank according to the present invention. Form.
And after forming a taper part (12), the said welding surface (11) will be located between a taper part (12) and a weld part (20).

Next, as shown in FIG. 3, the manufacturing process of the cutting part (21) is performed on the welded part (20), and the welded part (20) is provided with a blade groove (22) that can be drilled and cut.
Since the welded part (20) is made of less material than the base part (10), when the cutting part (21) is produced, the welded part (20) only scrapes a small amount of tungsten steel.
Therefore, for the manufacturer of the drill bit, as the consumption amount of the expensive tungsten steel is reduced, the waste generated in the manufacturing process can be reduced, and the cost can be greatly reduced.

  4 and 5 show a second embodiment of a process of manufacturing a drill bit for a printed wiring board by subsequent processing in a drill blank manufactured by the present invention.

In this embodiment, the taper portion (12) of the base material portion (10) in FIG. 2 is changed, and in this embodiment, the end of the welded portion (40) is the end of the base material portion (30). Since it welds and is fixed to the part location, the welding surface (31) is formed between the welding part (40) and the base-material part (30).
Further, a taper portion (32) is formed on the base material portion (30), and the taper portion (32) is close to the position of the weld surface (31), and the taper portion (32) and the weld portion (40). A connecting portion (33) having the same diameter as the welded portion (40) is formed between the two.
The connecting portion (33) further extends at the tapered portion (32).
That is, the connecting portion (33) and the tapered portion (32) are located at the end portion of the base portion (30) and are adjacent to the welded portion (40).
Since this connecting portion (33) is formed by further reducing the diameter when polishing the tapered portion (32), the connecting portion (33) has the same diameter as the diameter of the welded portion (40). The application of the connecting portion (33) is to shorten the length of the welded portion (40).
This allows the weld (40) to be made with less material.
At this time, the welding surface (31) is located between the connecting portion (33) and the welded portion (40).

Furthermore, as shown in FIG. 5, the cutting part (41) is manufactured in the welding part (40).
In the production of the cutting part (41), the consumption of the material of the welded part (40) is small, so that a material saving effect can be achieved.

  6 and 7 show a third embodiment of a process of manufacturing a drill bit for a printed wiring board by subsequent processing in a drill blank manufactured by the present invention.

In this embodiment, the base material portion (10) in FIG. 1 is changed.
In the present embodiment, the taper portion (51) is manufactured by polishing at one end of the base material portion (50), and this taper portion (51) is welded to the end face portion away from the base material portion (50). A surface (52) is formed.
The welding surface (52) is for welding and fixing the welded portion (60), and the cross-sectional dimension of the welded surface (52) is larger than the diameter of the welded portion (60).
Subsequent processing and manufacturing steps are the same as those described above, and thus description thereof is omitted.

It is a top view which connected the welding part and base material part in 1st Example of this invention mutually. It is the top view which connected the base material part which has the welding part and taper part in 1st Example of this invention mutually. It is a three-dimensional external view after producing a drill bit in the first embodiment of the present invention. It is the top view which connected the base material part which has the welding part and taper part, and connection part in 2nd Example of this invention mutually. It is a three-dimensional external view after producing a drill bit in the second embodiment of the present invention. It is a top view before connecting the base material part which has a welding part and a taper part in 3rd Example of this invention. It is the top view which connected the base material part which has the welding part and taper part in 3rd Example of this invention mutually. It is a top view of the conventional drill blank. It is a three-dimensional external view after manufacturing a drill bit with the conventional drill blank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Base material part 11 Welding surface 12 Tapered part 20 Welding part 21 Cutting part 22 Blade groove 30 Base part 31 Welding surface 32 Taper part 33 Connection part 40 Welding part 41 Cutting part 50 Base material part 51 Tapered part 52 Welding surface 60 Welding Part 70 base part 71 welding surface 80 welding part 81 taper part 82 cutting part

Claims (8)

A multi-stage drill blank of a cutting tool for printed wiring boards, comprising a welded portion of tungsten steel material and a base material portion of stainless steel material,
One end of the weld is fixed to the center of the one end of the base by a welding method,
Moreover, the diameter and length of the weld are less than the diameter and length of the substrate,
A welding surface is formed between the base material portion and the welded portion,
Combined multi-stage drill blank for printed wiring board cutting tools.   The diameter ratio of a welding part and a base material part is 1/5-3/5, The composite type multistage drill blank of the cutting tool for printed wiring boards of Claim 1 characterized by the above-mentioned.   The length ratio of a welding part and a base material part is 1/10-1/2, The compound type multistage drill blank of the cutting tool for printed wiring boards of Claim 1 or 2 characterized by the above-mentioned.   The combined multistage drill blank for a printed wiring board cutting tool according to claim 1 or 3, wherein the welded portion and the base material have a perfect cross section.   The composite multistage drill blank for a printed wiring board cutting tool according to claim 1 or 3, wherein a cross section of the welded part and the base material has a shape approximating a perfect circle.   The combined multistage drill blank for a printed wiring board cutting tool according to claim 1, wherein a taper portion is formed at a joint portion between the base portion and the weld portion.   The combined multistage drill blank for a printed circuit board cutting tool according to claim 6, wherein a connecting portion having the same diameter as the welded portion is formed between the tapered portion and the welded portion.   A taper portion is formed at a joint portion between the base material portion and the weld portion, and this taper portion is for welding and fixing the weld portion to an end surface portion away from the base material portion, and has a cross-sectional dimension. The composite multistage drill blank of the cutting tool for printed wiring boards according to claim 1, wherein a welding surface having a diameter larger than a diameter of the welded portion is formed.

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