A high-efficiency cutting drill tip and a three-blade drill bit

Abstract

The application discloses a high-efficiency cutting drill tip and a three-blade drill bit, which comprises a drill bit body; three main cutting edges are arranged on the drill bit body, three horizontal edge thinning opening angles are formed between the main cutting edges, and a drill tip in an S shape is formed at an axial top end of the drill bit body; a drill tip angle is further arranged, the drill tip angle is in a triangular pyramid shape, and an included angle of a triangular pyramid surface formed by the drill tip angle is smaller than that of the drill tip; a chip groove is formed at a horizontal edge thinning position of the main cutting edge, an edge band is formed at an edge of the drill bit body, and the edge band is integrated with an outer edge of the drill bit body; and the application is convenient to use and can effectively realize higher-precision, higher-efficiency, longer-life and more stable cutting machining.

Description

Technical Field

[0001] This invention relates to the field of three-flute drill bits for hole machining via cutting, specifically a high-efficiency cutting drill tip and a three-flute drill bit. Background Technology

[0002] A drill bit is a cutting tool used in general drills or drilling machines to cut circular holes. The basic principle of a drill bit is to rotate the cutting edge, cut the workpiece, and then remove drill chips through the drill groove. Commonly used drill bits include twist drills, flat drills, center drills, deep hole drills, and nesting drills. Although reamers and countersinks cannot drill holes in solid materials, they are conventionally classified as drill bits. The machining efficiency of drilling is closely related to the number of cutting edges, chip removal effect, tool rigidity, and tool material. With the continuous development of industrial machine tools, high efficiency, high precision, and high stability have become the goals pursued by all machining industries. Existing two-flute drills have relatively low cutting efficiency. Because only two cutting edges support the hole wall, the cylindricity, surface roughness, and dimensional tolerances of the hole are generally not high; the tool body rigidity is poor, affecting feed efficiency and machining precision; and the self-centering and guiding performance is poor, making them unsuitable for machining parts with pre-cast holes. Summary of the Invention

[0003] To solve the above problems, the present invention provides the following technical solution: a high-efficiency cutting drill tip and a three-flute drill bit, comprising a drill bit body; comprising three main cutting edges, wherein three chisel edge thinning opening angles are formed between the main cutting edges, and the drill tip formed at the axial top of the drill bit body is S-shaped; further comprising a drill tip angle, wherein the drill tip angle is a triangular pyramid shape, and the included angle of the triangular pyramid face is smaller than that of the drill tip; a chip removal groove is formed at the chisel edge thinning point of the main cutting edges, and a cutting edge is formed at the edge of the drill bit body, wherein the cutting edge is integral with the outer edge of the drill bit body.

[0004] Preferably, it also includes an internal cooling hole that extends axially through the main cutting edge.

[0005] Preferably, the ratio of the width of the chip removal groove to the width of the blade of the main cutting edge is 2.5.

[0006] Preferably, it also includes a drill core, which is the range encompassed by the radius distance from the center of the radial cross section of the drill bit body to the deepest point of the chip removal groove.

[0007] Preferably, the radial cross-sectional diameter of the drill bit body is set as d, and the core diameter is 0.35~0.4d.

[0008] Preferably, the surface roughness of the cutting edge is Ra0.2.

[0009] Preferably, the drill bit body is provided with a wear-resistant coating on its exterior.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: The three-blade design enhances the overall support force during cutting and improves cutting efficiency; the arc-shaped transverse blade, thinned by the shaped grinding wheel, forms a chip groove, improving chip breaking effect; the S-shaped drill tip with self-centering function improves self-centering ability and drilling performance; and the special groove line design, using the shaped grinding wheel to grind a groove cross-sectional area with a large groove-to-back ratio, increases the chip space while ensuring the rigidity of the tool body. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the radial cross-section of the present invention; Figure 2 This is a front view structural diagram of the present invention; Figure 3 This is a three-dimensional structural diagram of the present invention; In the diagram: 1. Drill body, 2. Main cutting edge, 3. Drill tip, 4. Drill tip angle, 5. Chip groove, 6. Cutting edge, 7. Internal cooling hole, 8. Drill core, B3. Chisel edge thinning angle. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] Reference Figure 1-3A high-efficiency cutting drill tip and three-flute drill bit includes a drill body 1; it includes three main cutting edges 2, with three chisel edge thinning opening angles B3 formed between the main cutting edges 2; the drill tip 3 formed at the axial top of the drill body 1 is S-shaped, and the drill tip 3 has multiple convex and concave arcs distributed on it; due to the increased number of cutting edges involved in the machining process, the drill bit can achieve strong feed while meeting the same feed per edge as a double-flute twist drill, improving machining efficiency by 30%; it also includes a drill tip angle 4, which is a triangular pyramid shape, and the included angle of the triangular pyramid surface is smaller than that of the drill tip 3; the vertex of the triangular pyramid surface first contacts the part with any point on the main cutting edge, producing an effective centering effect; and easily squeezes into the part, achieving good "biting". Chip removal grooves 5 are formed at the chisel edge thinning of the main cutting edges 2, and a cutting edge band 6 is formed at the edge of the drill body 1, the cutting edge band 6 being integral with the outer edge of the drill body 1. The slightly narrower arc space at the thinned section of the longer, arc-shaped transverse cutting edge forces the chips generated there to curl with a large deformation, achieving a forced chip breaking effect. Furthermore, the cutting edge 6 increases the arc length in contact with the hole wall in the section perpendicular to the axis, improving the drill's constraint during cutting and contributing to better cylindricity and dimensional accuracy of the machined hole.

[0014] It also includes an internal cooling hole 7, which axially penetrates the main cutting edge 2. The width ratio of the chip removal groove 5 to the blade width of the main cutting edge 2 is 2.5, which is much higher than the back-to-back ratio of a general drill bit, greatly increasing the drill bit's chip capacity and allowing chips to be discharged very smoothly. It also includes a drill core 8, which is the range encompassed by the radius distance from the center of the radial cross-section of the drill bit body 1 to the deepest point of the chip removal groove 5. The diameter of the radial cross-section of the drill bit body 1 is set as d, and the diameter of the drill core 8 is 0.35~0.4d, which increases the rigidity of the tool body and provides a guarantee for powerful feed. The surface roughness of the cutting edge 6 is Ra0.2, which increases the grinding effect on the hole wall and improves the inner surface roughness of the hole; the drill bit body 1 is coated with a wear-resistant titanium carbonitride coating.

[0015] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency cutting three-flute drill bit, comprising a drill bit body (1); characterized in that: The drill bit body (1) includes three main cutting edges (2), which form three chisel edge thinning opening angles (B3). The drill tip (3) formed by these chisel edge thinning angles is S-shaped. The drill tip angle (4) is also included. The drill tip angle (4) is a triangular pyramid, and the included angle of the triangular pyramid is smaller than that of the drill tip (3). Chip removal grooves (5) are formed at the chisel edge thinning points of the main cutting edges (2). A cutting edge band (6) is formed between the chip removal groove (5) and the edge of the drill bit body (1). The cutting edge band (6) is integral with the outer edge of the drill bit body (1). The drill bit body (1) also includes an internal cooling hole (7) that axially penetrates the main cutting edges (2). The ratio of the width of the chip removal groove (5) to the width of the cutting edge of the main cutting edge (2) is 2. .5; also includes a drill core (8), the drill core (8) being the range encompassed by the radius distance from the center of the radial cross section of the drill bit body (1) to the deepest point of the chip removal groove (5); the diameter of the radial cross section of the drill bit body (1) is set as d, and the diameter of the drill core (8) is 0.35~0.4d; the surface roughness of the cutting edge (6) is Ra0.2; the drill bit body (1) is provided with a wear-resistant coating on its exterior.

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