(1) Differences:

1. Twist drill bits cannot drill white steel and other special metals. Metal drill bits generally add alloy steel and can drill special metal materials.

2. The ones that can drill special metal materials are the most widely used. Usually the diameter range is 0.25~80 mm. It is mainly composed of working part and handle. The working part has two spiral grooves, which are shaped like twists, hence the name. In order to reduce the friction between the guide part and the hole wall when drilling, the twist drill gradually decreases in diameter from the drill tip to the shank and takes on an inverted cone shape.

The twist drill mainly affects the rake angle of the cutting edge, blade strength and performance, which is usually 25° to 32°. The spiral groove can be processed by grinding, grinding, hot rolling or hot extrusion. The front end of the drill bit is sharpened to form the cutting part.

3. The vertex angle of the cutting part of a standard twist drill is 11°, the chisel edge bevel angle is 40°~60°, and the relief angle is 8°~20°. Due to structural reasons, the rake angle is large at the outer edge and gradually decreases toward the middle. The rake angle is negative at the chisel edge (up to about -55°), which acts as a squeeze during drilling. In order to improve the cutting performance of the twist drill, the cutting part can be ground into various shapes (such as) according to the properties of the material being processed.

4. There are two types of twist drill shank: taper shank. The former is clamped in the drill chuck during processing, and the latter is inserted into the taper of the spindle or tailstock. Generally used for twist drill manufacturing. Twist drills with welded blades or crowns are suitable for processing cast iron, hardened steel and non-metallic materials. Small solid carbide twist drills are used for processing instrument parts and printed circuit boards.

The drill handle of the carbide drill bit is made of medium carbon steel, and the head is inlaid with carbide for cutting.

Twist drills describe drill bits in terms of shape, while metal drills describe them in terms of processing methods. There is no fundamental difference between the two. However, common twist drills can be used to process metal or non-metal materials, while metal drills are mainly used for processing non-metal materials such as concrete.

Twist drill describes the drill bit from the shape, and the metal is described from the processing method. There is no fundamental difference between the two. However, common twist drills can be used to process metal or non-metal materials, while impact drills are mainly used for processing non-metal materials such as concrete.

(1) Main structure:

1. A drill bit, including a tool bar (1), the tool bar has a tip, and two tips are located on a main plane (C -C) a cutting insert (5, 5') with a short central cutting edge oriented in the first and second plane (E-E). The cutting edge forms a point-like central cutting edge for entering the workpiece and thereby centering the drill bit. Two chip removal grooves (6, 6') are provided on the cutter bit shank, and the chip removal grooves (6, 6') extend from the tip to the bottom. On any section along the tool shank, the chip flutes are located radially opposite to each other on the tube plane, which is the same as the edge plane of the two lands on both sides of the tube (F- F) Extended at 90°, the cutter bar has maximum rigidity in this plane. The second plane (E-E) of the center cutting edge is oriented at an angle of approximately 90° to the main rigid direction (F-F) of the land plane or the bottom end of the tool holder.

2. In drilling operations on concrete, etc., it can alleviate the sudden change of drilling status and make the drilling operations stable. Even when large chips are generated, the drilling efficiency is improved. Drill bit that will not lower.

3. The cutting edge portion is arranged in a substantially radial shape, has at least two main cutting edge portions, and is arranged between the main cutting edge portions in the circumferential direction. , at least two auxiliary cutting edge parts, the main cutting edge part has a main cutting edge as its cutting edge, the inner end of the main cutting edge is located at the center of rotation, and the outer end is located at the outer edge of the rotation trajectory of the cutting edge part.< /p>

3. The auxiliary cutting edge portion has a auxiliary cutting edge as its cutting edge. The inner end of the auxiliary cutting edge is located deviated from the rotation center toward the outer diameter side, and the outer end is located deviated toward the rotation center side. at the outer edge of the rotation path of the cutting edge.

4. A drill bit including a plurality of cutting edge portions arranged at the front end of the drill bit, and a shaft-shaped drill bit provided on the base end side of the cutting edge portion and having a shank formed on the base end portion. Main body;

5. The cutting edge portion has a cutting edge formed by the joint edge of the cutting surface and the clearance surface protruding from the front end side. The cutting edge extends from the drill bit rotation center side to the outer diameter. The sides are arranged in a substantially radial shape;

6. It utilizes the compound action of rotational action and axial direction action to perform impact cutting, characterized in that the cutting edge portion has at least 2 main cutting edge portions, And at least two secondary cutting edge portions are arranged between the main cutting edge portion and the main cutting edge portion in the circumferential direction;

7. The main cutting edge portion has as its cutting edge The main cutting edge, the inner end of the main cutting edge is located at the center of rotation, and the outer end is located at the outer edge of the rotation trajectory of the cutting edge portion, the secondary cutting edge portion has a secondary cutting edge as its cutting edge, the secondary cutting edge The inner end of the blade is located at a position deviated from the rotation center to the outer diameter side, and the outer end is located at a position deviated from the outer edge of the rotation path of the cutting blade portion toward the rotation center side.

(2) Installation and disassembly:

Suitable for the installation and disassembly of various drill bits. Installation and disassembly are convenient and reliable.

1. Drill bit installation: Slowly lift the drill bit box, put the four legs of the drill bit box into the four holes of the drill turntable, and select the corresponding drill bit box core board according to the specifications of the drill bit. Lift the core plate of the drill bit box and put it into the drill bit box body. Then match the groove of the drill bit to be installed with the convex tip of the core plate of the drill bit box. Put the drill bit into the drill bit box and the drill bit will be stuck in the center of the turntable. Then screw on the drill bit to connect the nut to the drill pipe.

2. Drill bit disassembly: Lift the drill rod (with drill bit), connect the drill bit box to the turntable as required in ①, lift the drill rod slowly to make the drill bit groove correspond to the convex tip of the drill bit box core plate. Put the drill bit in the drill bit box and remove the drill rod and drill bit in sequence.