CN107081457B

CN107081457B - High-stability self-centering drill bit

Info

Publication number: CN107081457B
Application number: CN201710517688.4A
Authority: CN
Inventors: 彭路贵; 彭浩; 伍超; 唐永华
Original assignee: Chengdu Fengyi Precision Tools Manufacture Co ltd
Current assignee: Chengdu Fengyi Yinhu Cnc Tool Co ltd
Priority date: 2017-06-29
Filing date: 2017-06-29
Publication date: 2023-06-16
Anticipated expiration: 2037-06-29
Also published as: CN107081457A

Abstract

The invention discloses a high-stability self-centering drill bit, which is characterized in that two chip grooves are symmetrically arranged on two sides of the drill bit, the tip of the drill bit is upwards arranged, the center part of the drill bit is upwards protruded along the center of the drill bit to form a center tip, the surfaces, which are positioned on the upper surface of the drill bit and are positioned on the outer sides of the two sides of the center tip, of the drill bit are respectively provided with an outer rear cutter surface, the top of the center tip is provided with a linear chisel edge, the two sides of the chisel edge extend outwards and downwards to form two transverse cutter surfaces, two inner rear cutter surfaces and two inclined rear cutter surfaces in sequence, two transition surfaces are respectively formed between the two ends of the chisel edge and the two chip grooves, the two outer ends of the chisel edge are respectively connected with two inner cutters, two inclined cutters and two outer cutters in sequence, and the inclined cutters are formed by interconnecting the straight line cutters in the middle and the arc cutters at the two ends. According to the invention, the center tip is arranged, and the chisel edge, the inner edge, the inclined edge, the transverse cutting edge surface, the inner rear cutting edge surface and the inclined rear cutting edge surface are arranged on the center tip, so that the positioning effect of the drill point is obviously improved, the drill can be directly drilled without pre-drilling, and deep hole processing can be efficiently and stably completed.

Description

High-stability self-centering drill bit

Technical Field

The invention relates to a drill bit, in particular to a high-stability self-centering drill bit which does not need to drill a pre-hole in deep hole processing and has small shaking during drilling.

Background

Hole machining is one of the most common and relatively difficult machining types in the field of modern machine manufacturing, and is widely used in various fields such as general machinery, automobile part manufacturing, aerospace, engineering machinery, electric machinery, petroleum equipment, and the like.

With the continuous progress of the technology, the processing efficiency of drilling processing has been improved by times, the traditional high-speed steel drill bit is reduced, and the integral hard alloy coating drill bit has been widely applied. In order to reduce the cost, when drilling holes with larger diameters, new types of shallow hole drill (U-drill) bits, spade drill bits, and replaceable bit bits with replaceable blades are beginning to be widely used. However, for the drill bit with the diameter (the ratio of the depth to the aperture) being larger than 6 times, in general, no matter the drill bit is an integral alloy drill bit or an alternative drill bit, a pre-hole is usually required to be drilled, namely, a short drill bit with the same diameter is used for drilling a shallow hole with a certain depth, and then a longer drill bit is used for continuously drilling a deep hole under the guidance of the shallow hole. If a long drill bit is used for directly drilling a deep hole, the drill bit can shake on the surface of a workpiece due to long drill bit and poor rigidity, and the drill bit is difficult to position at one point to drill the workpiece. The precision of the drilled holes is low, the holes can drift rather than be straight, the finish degree of the hole walls is poor, and the waves are easy to generate.

Such as: the patent number ZL200980108586.0 discloses a cutting tool with a chisel edge, and discloses a chisel edge with double cutting edges and a chisel edge angle between 80 degrees and 100 degrees, which solves the problem of shaking of the drill point to a certain extent, but in practical application, the problem of poor centering effect is often found. The reason is that the raised chisel edge of the common drill bit is raised, so that the axial drilling force of drilling is reduced, the workpiece is easier to drill, but the radial swing preventing effect of the drill bit is not strong enough, the centering effect is not strong when the drilling force is larger or the feeding is accelerated, the drill bit generates radial swing, the hole wall generates corrugation, and the precision of the hole is reduced.

Disclosure of Invention

The invention aims to solve the problems and provide a high-stability self-centering drill bit which does not need to drill a pre-hole in deep hole processing and has small shaking during drilling.

The invention realizes the above purpose through the following technical scheme:

the self-centering drill bit with high stability is characterized in that two chip removal grooves are symmetrically formed in two sides of the self-centering drill bit, the tip of the drill bit is upwards, the central part of the drill bit protrudes upwards along the central line of the drill bit to form a central tip, and the surfaces, located on the outer sides of the central tip, of the upper surface of the drill bit are respectively outer rear cutter surfaces; the top of the center tip is a linear chisel edge, two sides of the chisel edge extend downwards to form two transverse blade surfaces, two inner rear blade surfaces and two inclined rear blade surfaces in sequence, two ends of the chisel edge are respectively connected with two chip grooves to form two transition surfaces, the two transition surfaces are respectively connected with a straight blade formed by intersecting the two outer rear blade surfaces and an arc blade extending outwards from the straight blade to form two outer blades, an inclined blade is respectively formed between one side edge of the two transition surfaces and the corresponding inclined rear blade surface, a linear inner blade is respectively formed between one side edge of the two transition surfaces and the corresponding inner rear blade surface, two inner blades, two inclined blades and two outer blades are sequentially connected outside two ends of the chisel edge, the inclined blades are formed by connecting the straight blades in the middle with the arc blades at the two ends, and the maximum distance between the two inclined blades is 20% -23% of the maximum diameter of the drill tip; the height difference between the top of the center tip and the upper ends of the two outer blades is 0.5-0.8mm, the included angle between the straight blades in the two outer blades is 145-147 degrees, the included angle between the straight blades in the two inclined blades is 2-6 degrees, and the included angle between the two inner blades is 138-140 degrees.

Further, the included angle between the inclined rear cutter surface and the central line of the drill point is 2-6 degrees, the length of the chisel edge is 1-3mm, the chisel edge is an arc edge, the arc radius of the chisel edge is 0.5-1.5mm, and the chisel edge surface extends from bottom to top in a curve mode to form a wedge shape.

The invention has the beneficial effects that:

according to the invention, the center tip is provided with the chisel edge, the inner blade, the inclined blade, the transverse blade surface, the inner rear blade surface and the inclined rear blade surface, so that the positioning effect of the drill tip is obviously improved, the radial swing of the drill bit can be prevented as much as possible while the strength of the center tip is ensured by properly controlling the height difference between the top of the center tip and the upper end of the outer blade, a good positioning effect is achieved, and especially, the drill bit with the length-diameter ratio of more than or equal to 6 times of the hole can be directly drilled without drilling a pre-hole, and deep hole processing with high finish, high straightness, high verticality and no corrugation on the hole wall can be efficiently and stably completed.

Drawings

FIG. 1 is a schematic perspective view of a high stability self-centering drill bit according to the present invention;

FIG. 2 is a schematic diagram of the front view of the high stability self-centering drill bit of the present invention;

FIG. 3 is a schematic left-hand structural view of the high stability self-centering drill bit of the present invention;

FIG. 4 is a schematic top view of the high stability self-centering drill bit of the present invention, with a corresponding front view angle different from FIG. 2;

fig. 5 is a schematic view of the high stability self-centering drill bit of the present invention after being mounted on a drill rod.

Detailed Description

The invention is further described below with reference to the accompanying drawings:

as shown in fig. 1-4, the high-stability self-centering drill bit 8 of the present invention is symmetrically provided with two junk slots 7a and 7b on two sides, the tip of the drill bit 8 is provided upwards, the center part of the drill bit 8 protrudes upwards along the center line thereof to form a center tip 7, and the surfaces, located on the upper surface of the drill bit 8 and outside the two sides of the center tip 7, are respectively provided with outer rear tool surfaces 9a and 9b; the top of the center tip 7 is a linear chisel edge 2, two sides of the chisel edge 2 extend downwards and outwards to form two chisel edge surfaces 5a/5b, two inner chisel edge surfaces 11a/11b and two inclined chisel edge surfaces 10a/10b in sequence, two transition surfaces 6a and 6b are respectively formed between two ends of the chisel edge 2 and two chip grooves 7a and 7b, a straight edge formed by intersecting the two transition surfaces 6a and 6b with two outer chisel edge surfaces 9a and 9b and an arc edge extending towards the outer edge of the straight edge form two outer edges 1a and 1b, two inclined edges 3a and 3b are respectively formed between one side edge of the two transition surfaces 6a and 6b and the corresponding two inclined chisel edge surfaces 10a and 10b, straight inner edges 4a and 4b are respectively formed between one side edge of the two transition surfaces 6a and 6b and the corresponding two inner chisel edge surfaces 11a and 11b, two ends of the chisel edge 2 are respectively connected with two inner edges 4a/4b and 4a and 3b in sequence, two inclined edges 3a and 3D are respectively formed between two sharp edges 3a and 3D, and the maximum distance between two inclined edges 3D and 3D are respectively formed between two sharp edges 3D and two sharp edges 3D are respectively; the height difference w between the top of the center tip 7 and the upper ends of the two outer blades 1a and 1b is 0.5-0.8mm, the included angle 1 beta between the straight blades in the two outer blades 1a and 1b is 145-147 degrees, the included angle 3 beta between the straight blades of the two inclined blades 3a and 3b is 2-6 degrees, the included angle between the two inner blades 4a and 4b is 138-140 degrees, the length h of the chisel blade 2 is 1-3mm, the chisel blade is an arc blade with the arc radius of 0.5-1.5mm, the two

chisel blade surfaces

5a and 5b respectively extend from bottom to top in a curve to form a wedge shape, and the included angle 2 beta between the extension straight lines at the two ends of the chisel blade 2 is 138-140 degrees; two transition surfaces 6a and 6b are formed by extending the "L" section curve with the circular arc R obliquely downward from the two end points H, K of the chisel edge 2 in the direction of an angle θ (38 ° -42 °) and intersect with the two row cutting grooves 7a and 7b, respectively.

As shown in fig. 5, in application, the drill tip 8 is disposed on the cutter bar 20 in a specific manner: the bottom of the drill tip 8 is designed to be a joint which is convenient for quick assembly and disassembly to form a bit with a replaceable head, so that quick assembly and disassembly with the cutter bar 20 can be realized; or the drill tip 8 and the tool holder 20 may be designed in other ways as desired. The mounting of the drill tip 8 on the tool shank 20 enables good self-centering, especially when the aspect ratio of the hole is greater than 6 times. The drill point 8 can directly drill holes without pre-drilling, so that good hole size precision, straightness and smoothness can be obtained, and no ripple is generated.

The above embodiments are only preferred embodiments of the present invention, and are not limiting to the technical solutions of the present invention, and any technical solution that can be implemented on the basis of the above embodiments without inventive effort should be considered as falling within the scope of protection of the patent claims of the present invention.

Claims

1. The utility model provides a high stability is from centering drill bit, its bilateral symmetry is equipped with two junk slots, its characterized in that: the tip of the drill tip is arranged upwards, the central part of the drill tip protrudes upwards along the central line of the drill tip to form a central tip, and the surfaces, which are positioned on the upper surface of the drill tip and are positioned outside the two sides of the central tip, are respectively outer rear cutter surfaces; the top of the center tip is a linear chisel edge, two sides of the chisel edge extend downwards to form two transverse blade surfaces, two inner rear blade surfaces and two inclined rear blade surfaces in sequence, two ends of the chisel edge are respectively connected with two chip grooves to form two transition surfaces, the two transition surfaces are respectively connected with a straight blade formed by intersecting the two outer rear blade surfaces and an arc blade extending outwards from the straight blade to form two outer blades, an inclined blade is respectively formed between one side edge of the two transition surfaces and the corresponding inclined rear blade surface, a linear inner blade is respectively formed between one side edge of the two transition surfaces and the corresponding inner rear blade surface, two inner blades, two inclined blades and two outer blades are sequentially connected outside two ends of the chisel edge, the inclined blades are formed by connecting the straight blades in the middle with the arc blades at the two ends, and the maximum distance between the two inclined blades is 20% -23% of the maximum diameter of the drill tip; the height difference between the top of the center tip and the upper ends of the two outer blades is 0.5-0.8mm, the included angle between the straight blades in the two outer blades is 145-147 degrees, the included angle between the straight blades in the two inclined blades is 2-6 degrees, and the included angle between the two inner blades is 138-140 degrees; the length of the chisel edge is 1-3mm, the chisel edge is an arc edge, the arc radius of the chisel edge is 0.5-1.5mm, and the chisel edge surface extends from bottom to top in a curve to form a wedge type.