CN111496294B

CN111496294B - Step crescent drill

Info

Publication number: CN111496294B
Application number: CN202010353174.1A
Authority: CN
Inventors: 曾继钊; 龙昌演; 韩建清; 杨琎; 周翔; 姜钟焮; 曾令辉; 方金财; 钟传琴
Original assignee: Guizhou Zhenhua Hualian Electronics Co ltd
Current assignee: Guizhou Zhenhua Hualian Electronics Co ltd
Priority date: 2020-04-29
Filing date: 2020-04-29
Publication date: 2022-02-11
Anticipated expiration: 2040-04-29
Also published as: CN111496294A

Abstract

The invention provides a step semilunar drill which comprises a drill handle, a connecting neck, a first cutting edge and a second cutting edge, wherein the drill handle, the connecting neck, the first cutting edge and the second cutting edge are fixedly connected in sequence and the central lines of the drill handle, the connecting neck, the first cutting edge and the second cutting edge are on the same straight line; the cross sections of the first cutting edge and the second cutting edge are processed into semi-circles, the end of the second cutting edge is processed with a roughness reducing structure, and an axial cutting force reducing structure is processed between the first cutting edge and the second cutting edge. The semi-moon drill is adopted, when non-ferrous metal materials are processed, the semicircular cutting edge can contain more metal chips, and the chip grooves are formed in the step of the cutting edge to reduce the axial force received by the cutting edge. According to the invention, the enough chip containing spaces are arranged at the tip, the middle part and the rear end of the cutting tool, so that the influence of metal chips on the cutting edge is greatly reduced, the axial cutting force of the cutting edge is reduced, and the surface roughness of a workpiece is ensured.

Description

Step crescent drill

Technical Field

The invention relates to a step crescent drill.

Background

When the hole of the non-ferrous metal material is machined, the non-ferrous metal material is low in hardness and sticky, so that the non-ferrous metal material is easy to cut and difficult to remove chips during machining, the hole diameter of a workpiece is enlarged, and the surface roughness is poor. The common drill bit is processed, and the common drill bit has two cutting edges and two chip grooves, so that the drill bit is easily blocked in the grooves when a large amount of processing chips exist, and the drill bit is abraded and even broken; secondly, the existing half-moon drill has a simple structure and cannot meet the processing requirements of deep and small blind hole workpieces and step hole one-step forming workpieces with high surface roughness requirements.

Disclosure of Invention

In order to solve the technical problems, the invention provides a step half-moon drill which meets the processing requirements of a deep and small blind hole workpiece made of a non-ferrous metal material and a step hole one-step forming workpiece with high surface roughness requirement. The purposes of improving the surface roughness of the hole, improving the processing efficiency and reducing the cost are achieved.

The method is realized by the following technical scheme.

The invention provides a step semilunar drill which comprises a drill handle, a connecting neck, a first cutting edge and a second cutting edge, wherein the drill handle, the connecting neck, the first cutting edge and the second cutting edge are fixedly connected in sequence and the central lines of the drill handle, the connecting neck, the first cutting edge and the second cutting edge are on the same straight line; the cross sections of the first cutting edge and the second cutting edge are processed into semi-circles, the end of the second cutting edge is processed with a roughness reducing structure, and an axial cutting force reducing structure is processed between the first cutting edge and the second cutting edge. The semi-moon drill is adopted, when non-ferrous metal materials are processed, the semicircular cutting edge can contain more metal chips, and the chip grooves are formed in the step of the cutting edge to reduce the axial force received by the cutting edge.

Further, in order to guarantee some surface roughness of work piece processing, the second cutting edge is the semicircle columnar order, has the fillet between the arc surface of second cutting edge and the terminal surface, and cutting edge tip processing is convex, and the arc surface can be polished the machined surface in carrying out the cutting process, has guaranteed the roughness of machined surface.

Furthermore, in order that metal chips generated by cutting at the top end of the cutting edge cannot obstruct the rotation of the cutting edge and increase the axial stress of the cutting edge, the radius of the fillet is 2-1.5 times of the radius of the second cutting edge, so that the metal chips generated by cutting at the cutting edge have enough space to be discharged, and the metal chips cannot be blocked between the cutting edge and a processing surface to influence the precision of a workpiece.

Further, avoid the cutting edge to receive the fillet influence, reduce its cutting efficiency to the work piece, set up the contained angle between the half-section of fillet and second cutting edge to 8~10, make its pointed end keep certain drilling ability.

Furthermore, in order to enable the metal chips generated in the rear end machining process of the first cutting edge and the metal chips generated in the front end machining process of the first cutting edge to be concentrated at one position to cause the axial stress of the cutting edge to be increased, a concave chip pocket is arranged at the first cutting edge and the second cutting edge, so that the metal chips quickly enter the chip pocket after being cut off, and the metal chips and the front end metal chips are prevented from being mixed to increase the friction force between the cutting edge and the machining surface. The first cutting edge is in a semicircular table shape, and the diameter of one end, fixedly connected with the second cutting edge, of the first cutting edge is 0.5-0.6 mm smaller than that of the second cutting edge.

Furthermore, in order to enable metal scraps generated by the first cutting edge and the second cutting edge to have accommodating spaces in the whole machining process, the half sections of the first cutting edge and the second cutting edge are connected into a flat plane, and the overall length of the plane is greater than 3-5 mm of the machining depth of the workpiece.

And in order to smoothly discharge the metal chips, the half sections of the first cutting edge and the second cutting edge are connected into a flat plane. The flat front surface is smoothly connected with a chip removal slope processed on the connecting neck.

Furthermore, the included angle between the chip removal slope and the central line of the connecting neck is 20-40 degrees, and under the condition that the strength of the connecting neck is not reduced, the slope of 20-40 degrees can not generate too large chip removal resistance on metal chips.

The invention has the beneficial effects that: the sufficient chip containing spaces are arranged at the tip, the middle and the rear end of the cutting tool, so that the influence of metal chips on the cutting edge is greatly reduced, the axial cutting force of the cutting edge is reduced, and the surface roughness of a workpiece is ensured.

Drawings

FIG. 1 is a front view of the present invention;

FIG. 2 is a side view of the present invention;

FIG. 3 is an enlarged view of a portion of FIG. 1 in accordance with the present invention;

FIG. 4 is an enlarged view of a portion of the present invention at FIG. 2B;

FIG. 5 is a block diagram of an embodiment of the present invention;

in the figure: 1-processing equipment, 2-clamp, 3-workpiece, 4-half-moon drill, 41-drill handle, 42-connecting neck, 43-first cutting edge, 44-second cutting edge, 45-chip groove, 46-edge, 47-chip removal slope, 48-chip removal section, 5-collet chuck and 6-tailstock.

Detailed Description

The technical solution of the present invention is further described below, but the scope of the claimed invention is not limited to the described.

A step semilunar drill comprises a drill handle 41, a connecting neck 42, a first cutting edge 43 and a second cutting edge 44 which are fixedly connected in sequence and the central lines of which are on the same straight line; the first cutting edge 43 and the second cutting edge 44 are formed in a semicircular shape in cross section, the end of the second cutting edge 44 is formed with a roughness reducing structure, and an axial cutting force reducing structure is formed between the first cutting edge 43 and the second cutting edge 44.

The second cutting edge 44 is a semi-cylindrical shape, and a fillet is formed between the arc surface and the end surface of the second cutting edge 44.

The radius of the fillet is 1.2-1.5 times of the radius of the second cutting edge 44.

The included angle between the fillet and the plate section of the second cutting edge 44 is 8-10 degrees.

The first cutting edge 43 is in a shape of a semicircular truncated cone, and the diameter of one end, fixedly connected with the second cutting edge 44, of the first cutting edge 43 is smaller than the diameter of the second cutting edge 44 by 0.5-0.6 mm.

The half sections of the first cutting edge 43 and the second cutting edge 44 are connected into a flat plane, and the overall length of the plane is larger than the machining depth of a workpiece by 3-5 mm.

The flat front surface is smoothly connected with a chip removal ramp 47 machined on the coupling neck 42.

The included angle between the chip removal slope 47 and the central line of the connecting neck 42 is 20-40 degrees.

Example 1: as shown in fig. 1 to 5, in the present embodiment, a stepped hole is machined, the deep hole is a cylindrical hole, the shallow hole is a tapered hole, in the embodiment, the first cutting edge 44 for machining the deep hole is machined into a semicircular shape, the second cutting edge is in a semicircular frustum shape, a fillet with a radius 1.3 times larger than that of the first cutting edge is poured out from the tip of the first cutting edge, an included angle between the fillet and a half section of the fillet is 9 °, the diameter of one end of the second cutting edge 43 connected with the first cutting edge 44 needs to be smaller than 0.52mm of the diameter of the first cutting edge 44, the length of the second cutting edge 43 is correspondingly lengthened by 3.2mm, and the sum of the section lengths of the first cutting edge 44 and the second cutting edge 43 is larger than the depth of the hole;

the calculation formula for the length calculation of the connecting neck 42 is its radius ÷ tan25 °, the angle can be adjusted in the range of 20 ° to 40 ° depending on the material strength.

Example 2: as shown in fig. 1 to 5, in the present embodiment, a stepped hole is machined, the deep hole is a cylindrical hole, the shallow hole is a tapered hole, in the embodiment, the first cutting edge 44 for machining the deep hole is machined into a semicircular shape, the second cutting edge is in a semicircular frustum shape, a fillet with a radius 1.4 times larger than that of the first cutting edge is poured out from the tip of the first cutting edge, an included angle between the fillet and a half section of the fillet is 10 °, the diameter of one end of the second cutting edge 43 connected with the first cutting edge 44 needs to be smaller than 0.58mm of the diameter of the first cutting edge 44, the length of the second cutting edge 43 is correspondingly lengthened by 4.2mm, and the sum of the section lengths of the first cutting edge 44 and the second cutting edge 43 is larger than the depth of the hole;

the calculation formula for the length calculation of the connecting neck 42 is its radius ÷ tan30 °, the angle can be adjusted in the range of 20 ° to 40 ° depending on the material strength.

Claims

1. The utility model provides a step semilune bores, includes in proper order rigid coupling and central line drill handle (41), connection neck (42), first cutting edge (43), second cutting edge (44) on the collinear, its characterized in that: the cross sections of the first cutting edge (43) and the second cutting edge (44) are processed into semi-circles, the end of the second cutting edge (44) is processed with a roughness reducing structure, and an axial cutting force reducing structure is processed between the first cutting edge (43) and the second cutting edge (44);

the second cutting edge (44) is of a semi-cylindrical shape, and a fillet is formed between the arc surface and the end face of the tail end of the second cutting edge (44);

the first cutting edge (43) is in a semicircular table shape, and the diameter of one end, fixedly connected with the second cutting edge (44), of the first cutting edge (43) is 0.5-0.6 mm smaller than that of the second cutting edge (44).

2. The step-crescent drill of claim 1, wherein: the radius of the fillet is 1.2-1.5 times of the radius of the second cutting edge (44).

3. The step-crescent drill of claim 2, wherein: the included angle between the fillet and the half section of the second cutting edge (44) is 8-10 degrees.

4. The step-crescent drill of claim 1, wherein: the half sections of the first cutting edge (43) and the second cutting edge (44) are connected into a flat plane, and the overall length of the plane is larger than the machining depth of a workpiece by 3-5 mm.

5. The step-crescent drill of claim 4, wherein: the flat plane is smoothly connected with a chip removal slope (47) processed on the connecting neck (42).

6. The step-crescent drill of claim 5, wherein: the included angle between the chip removal slope (47) and the central line of the connecting neck (42) is 20-40 degrees.