CN205129013U - A carbide chip dividing groove centre drill for PCB - Google Patents

Abstract

The utility model relates to a center drill bit for PCB, in particular to a hard alloy center drill bit for PCB. A cemented carbide chip-splitting center drill for PCB, which includes a cemented carbide integrally formed drill shank and a drill bit, the first relief angle of the drill bit is 15°, and the outer edge of the blade is provided with a split chip flute. The utility model can effectively guarantee the drilling quality, and the hole wall has high smoothness.

Description

Carbide chip splitter center drill for PCB

technical field

The utility model relates to a center drill bit for PCB, in particular to a hard alloy center drill bit for PCB.

Background technique

With the development of the electronic communication industry, the demand for PCB boards has increased sharply. In order to fix the PCB board or install certain devices, it is necessary to drill holes on the PCB board. Traditional products are usually designed with a single-blade chisel edge without treatment, which is relatively thick, and the chisel edge directly affects the axial force during processing. The chisel edge is responsible for cutting the center part of the hole. Since the rake angle of the chisel edge is a large negative rake angle, the chisel edge is severely squeezed during drilling and causes a large axial force, which accounts for 60-70% of the total axial force, which leads to poor drilling quality. High, especially the smoothness of the hole wall is difficult to meet the requirements.

Contents of the invention

The utility model aims at overcoming the defects of the prior art, and provides a hard alloy chip-separating groove center drill for PCB. The utility model can effectively guarantee the drilling quality, and the hole wall has high smoothness.

In order to solve the above-mentioned technical problems, a cemented carbide chip splitting center drill for PCB, it includes a drill shank and a cutting edge formed integrally with cemented carbide, the first relief angle of the cutting edge is 15°, the The main cutting edge of the blade is provided with a chip breaker.

In the hard chip splitter center drill for PCB, the second relief angle of the blade is 30°, the helix angle is 30°, and the apex angle is 128°-132°.

The hard chip splitter center drill used for PCB is a drill bit designed with double blades, and its diameter is 1.3-3.175mm.

The utility model uses cemented carbide as the base material, and grinding the chisel edge can reduce the part of the axial force received during the processing, that is, the first rear angle is adjusted to make the center drill sharper. Two chip splitting grooves are ground on the front edge of the spiral groove, which can reduce the chip width, facilitate chip removal, and improve wire wrapping. Therefore, the center drill of the present invention is particularly suitable for processing HDI boards, halogen-free boards and high TG boards.

Description of drawings

Below, in conjunction with accompanying drawing, the utility model is further described:

Fig. 1 is the schematic diagram of the utility model;

Fig. 2 is a partial enlarged view in the Z direction in Fig. 1;

Fig. 3 is a partial enlarged view along direction K in Fig. 1 .

detailed description

As shown in Fig. 1, Fig. 2 and Fig. 3, the utility model is a cemented carbide chip-separating groove center drill for PCB, which includes a drill shank 1 and a cutting edge 2 integrally formed of cemented carbide, and the cutting edge The first relief angle is 15°, and the main cutting edge of the blade is provided with a chip splitter. The chip splitting groove 3 is provided on the main cutting edge, which can reduce the chip width, facilitate chip removal, and reduce heat generation during drilling. Thereby improving the processing efficiency of the drill bit, improving the phenomenon of wire wrapping, and improving the smoothness of the hole wall.

In the hard chip splitter center drill for PCB, the second relief angle of the blade is 30°, the helix angle is 30°, and the apex angle is 128°-132°.

The hard chip splitter center drill used for PCB is a drill bit designed with double blades, and its diameter d is 1.3-3.175mm.

Claims (3)

1. A cemented carbide chip splitting center drill for PCB, which comprises a drill shank and a blade integrally formed of cemented carbide, is characterized in that, the first relief angle of the blade is 15°, the The main cutting edge of the blade is provided with a chip breaker. 2. The cemented carbide chip splitting center drill for PCB according to claim 1, characterized in that, the second relief angle of the blade is 30°, the helix angle is 30°, and the apex angle is 128°-132° . 3 . The cemented carbide chip splitter center drill for PCB according to claim 1 , characterized in that the center drill is a drill with a double-blade design, and its diameter is 1.3-3.175 mm.