To put it bluntly, a drill bit refers to a special tool used for drilling or drilling. These drill bits are usually made of metal and are used to drill or bury holes in physical raw materials.
A drill bit, consisting of a shank (1), with a center, with two cuttings on the main plane (CC) and a short central cutting bit on a second plane (EE) that sits on one main plane (CC) together (5.5′). The blade creates a point center cutting bit that enters the product workpiece and aligns the two ends of the bit. On the boring tool, set 2 face milling grooves (6.6′) widening from the top to the bottom. In other parts of the boring tool, the milling groove is located at the tangentially opposite position of the flat surface of the tube, and the flat surface of the tube and the two lands on both sides of the tube are widened by 90°. The bending stiffness of the boring tool on this plan is larger. The second plan view (E-E) of the center cutting head tends to be at an angle of approximately 90° to the plan view of the belt or the orientation (F-F) of the primary bending stiffness of the bottom end of the boring tool.
Types and main uses of drill bits.
The twist drill is the most commonly used special tool for hole making. Usually the diameter standard is 0.25~80mm. It is mainly composed of the working part of the drill bit and the rocker. Part of the work has two spiral grooves that look like marijuana flowers, hence the name. In order to better reduce the friction between the guiding part and the surface layer during the whole drilling process, the hole diameter of the twist drill is gradually reduced from the drill tip to the rocker. The helix angle of the twist drill mainly affects the size of the rake angle of the drilling edge. The strength and chip breaking characteristics of the blade surface are usually 25°~32°. The spiral groove can be processed by cutting, grinding, hot rolling or cold extrusion. A part of the standard twist drill drilling angle is 118, the inclination angle of the chisel edge is 40°~60°, and the rake angle is 8°~20°. Due to the construction, the declination angle is relatively large at the edges. Slowly decrease towards the positive center, the chisel edge is a negative declination angle (about -55°), and it has a squeezing effect when drilling.
In order to better improve the cutting characteristics of twist drills, the cutting part can be rolled into various shapes (such as group drills) according to the characteristics of the raw materials to be processed. There are 2 types of rockers for twist drills: single edge and tapered shank. During processing, the former is clamped in the drill chuck, and the latter is inserted into the taper hole of the lathe spindle or the lathe tool holder. Generally speaking, twist drills are made of spring steel. Twist drills embedded in electric-welded carbide tools or crowns are suitable for machining pig iron, hardened steel and non-metallic materials. Solid carbide tool twist drills are used to machine instrument panel parts and printed circuit boards.
The cutting part of the flat drill is spade-shaped, the structure is simple, the production is low cost, the cutting fluid is very easy to guide into the hole, but the cutting and chip breaking characteristics are poor. Flat drills are available in two configurations: integrated and prefabricated. The integrated type is suitable for microplates with a drilling diameter of 0.03~0.5mm. The prefabricated flat drill head is removable and can be internally cooled, suitable for holes with a diameter of 25~500mm.
Deep hole drilling machine
Deep hole drilling machines usually refer to special tools with a machining depth to diameter ratio of more than 6. Common ones are gun drill, A deep hole drilling machine, blowout drill, DF deep hole drilling machine, etc. Sleeve gauge drills are also commonly used in shallow hole drilling.
Drilling with 3 to 4 teeth, its bending rigidity is better than that of twist drills, which are used to expand the current holes and improve the machining precision and smoothness.
There are many cutter teeth used to process the countersunk head holes of various countersunk head bolts, or to level the outer and inner holes of the holes.
The center drill is used to drill the center hole of the shaft product workpiece. It is essentially a composite type of twist drill with a small helix angle and a hole drill, so it is also called a composite center drill.
Post time: Feb-19-2022