CN205342026U - Fluted drill in processing hole - Google Patents

Abstract

A twist drill for processing holes, comprising a cutter body, the cutter body has two spiral bodies, the two spiral bodies meet at the axis center of the front end of the cutter body, and form a chisel edge at the intersection, each of the spiral bodies has a The main cutting edge, the main cutting edge includes a front cutting edge and a middle cutting edge, the front cutting edge is connected with the chisel edge, the front cutting edges on the two helicoids have an included angle of 72°-76° between each other, and the cross cutting edge The length of the blade is 2.3-2.6mm. The utility model has better wear resistance.

Description

A twist drill for processing holes

technical field

The utility model relates to a cutting tool, in particular to a twist drill for processing holes.

Background technique

The hole processing of parts in the prior art usually needs to be arranged for operators to use special equipment and cutters. The cutter in the prior art has a structure as shown in Figure 1, including a cutter head 1 with a front edge 11 on the cutter head 1. The front blades 11 have an included angle of 125°-150°. The included angle between the front blades 11 of the tool with this structure is 125°-150°, and the tool has a relatively large axial force, but when in use, the tool and the workpiece wear a lot, and a sharp friction sound is generated, and the workpiece It is prone to deformation and concave; after a period of use, the front blade is severely worn and spherical, and cannot continue to cut.

Utility model content

The technical problem to be solved by the utility model is to provide a twist drill for processing holes with high wear resistance, so as to reduce the serious wear of the front cutting edge.

In order to achieve the above object, the twist drill for processing holes of the present invention includes a cutter body, the cutter body has two helicoids, the two helicoids meet at the axis of the front end of the cutter body, and form a chisel edge at the intersection, each There is a main cutting edge on one of the spiral bodies, the main cutting edge includes a front cutting edge and a middle cutting edge, the front cutting edge is connected with the chisel edge, and the front cutting edges on the two spiral bodies have an angle of 72° to 76° between each other. included angle, and the length of the chisel edge is 2.3-2.6mm.

In the aforementioned twist drill, at least one of the outer edges of the helical body is provided with an additional cutting edge, and the additional cutting edge is arranged transversely to the helical direction of the helical body where it is located.

In the aforementioned twist drill, wherein, the additional cutting edge has an apex angle of 50°-55°.

In the aforementioned twist drill, wherein, the middle cutting edge includes a multi-segment cutting body, and the multi-segment cutting bodies are connected end to end so that the middle cutting edge has a broken line profile.

The above-mentioned twist drill, wherein the middle edge includes:

a first blade body connected to an end of the front blade away from the chisel edge;

a second blade body connected to an end of the first blade body away from the front blade; and

The third blade body is connected with the end of the second blade body away from the first blade body.

The aforementioned twist drill, wherein the length of the first blade body is L1, the length of the second blade body is L2, and the length of the third blade body is L3, L1:L2:L3=3:2: 1.

The above-mentioned twist drill has a central axis, and a cross-section perpendicular to the central axis is set, and the front cutting edge has an included angle of 35°-38° with respect to the cross-section.

In the aforementioned twist drill, wherein, the first blade body has an included angle of 22°-26° relative to the cross-section plane.

In the aforementioned twist drill, wherein, the second blade body has an included angle of 12°-18° relative to the cross-section plane.

In the aforementioned twist drill, wherein, the third blade body has an included angle of 10°-14° relative to the cross-section plane.

The beneficial effect of the utility model is that: when processing a thin piece (such as a thin steel plate or a cardboard), the chisel edge first drills through the workpiece, and then the front blades on both sides scrape a large hole, based on the fact that the front blades have 72° to 76° The included angle and the length of the chisel edge are designed to be 2.3-2.6mm, and the drill tip of the twist drill has better wear resistance.

Moreover, based on the additional cutting edge and the middle edge design of the broken line profile, the hole can be further expanded and the hole wall has better surface roughness.

The utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the utility model.

Description of drawings

Fig. 1 is the structural diagram of a cutting tool of prior art;

Fig. 2 is the structural diagram of twist drill of the present utility model;

Fig. 3 is the top view of twist drill in Fig. 2;

Fig. 4 is an enlarged view of part A in Fig. 2;

Fig. 5 is an enlarged view of part B in Fig. 2;

FIG. 6 is an enlarged view of part C in FIG. 2 .

Among them, reference signs

1-head

11-front blade

2- cutter body

21, 22-helicoid

23- Chisel

24-Main blade

241-front blade

242-medium blade

2421-First blade body

2422-Second Blade

2423-Third Blade

25 - additional cutting edge

A1-central axis

M-cross section

L-length of chisel edge

L1-the length of the first blade body

L2- the length of the second blade body

L3- the length of the third blade body

detailed description

The technical scheme of the utility model is described in detail below in conjunction with the accompanying drawings and specific embodiments, so as to further understand the purpose, scheme and effect of the utility model, but not as a limitation of the scope of protection of the appended claims of the utility model.

Referring to Fig. 2 to Fig. 4, as shown in the figures, the twist drill for processing holes of the present invention includes a cutter body 2, and the cutter body 2 has two helicoids 21, 22, and the two helicoids 21, 22 are located at the front axis of the cutter body. and form a chisel edge 23 at the intersection, each spiral body 21, 22 has a main blade 24, the main blade 24 includes a front blade 241 and a middle blade 242, the front blade 241 is connected with the chisel edge 23, the two The front blades on the helix have an included angle α of 72°-76°, and the length L of the chisel edge 23 is 2.3-2.6 mm.

Referring to FIG. 5 , an additional cutting edge 25 is provided on the outer edge of the helical body 22 , and the additional cutting edge 25 is arranged transversely to the helical direction of the helical body 22 where it is located. Certainly, the additional cutting edge can also be provided on the outer edge of the spiral body 21 ; similarly, the additional cutting edge can also be provided on both the outer edge of the spiral body 21 and the outer edge of the spiral body 22 . Preferably, the additional cutting edge 25 has an apex angle β of 50°-55°.

Referring to FIG. 6 , the middle blade 242 includes a plurality of blade bodies connected end to end so that the middle blade has a broken line profile. Specifically, the middle blade 242 includes a first blade body 2421 , a second blade body 2422 and a third blade body 2423 . The first blade body 2421 is connected to an end of the front blade 241 away from the chisel edge 23 . The second blade body 2422 is connected to an end of the first blade body 2421 away from the front blade 241 . The third blade body 2423 is connected to an end of the second blade body 2422 away from the first blade body 2421 . The length of the first blade body 2421 is L1, the length of the second blade body 2422 is L2, and the length of the third blade body 2423 is L3, L1:L2:L3=3:2:1. Furthermore, preferably, the twist drill has a central axis A1, a cross-section M perpendicular to the central axis A1 is set, and the front cutting edge 241 has an included angle of 35°-38° relative to the cross-section M. The first blade body 2421 has an included angle of 22°˜26° relative to the transverse plane M. The second blade body 2422 has an included angle of 12°˜18° relative to the cross-section M. The third blade body 2423 has an included angle of 10°˜14° relative to the transverse plane M.

The twist drill of the present utility model is mainly used for processing holes on thin parts (such as thin steel plates or cardboards). Based on the above-mentioned structural settings, when the utility model is in use, the chisel edge 23 first drills through the workpiece, and then the front blades 241 on both sides The large hole is scraped out, and the hole expansion is further completed by the additional cutting edge 25 . Based on the design that the front blades have an included angle of 72°-76° and the length of the chisel edge is 2.3-2.6 mm, the twist drill of the present invention has better wear resistance. Moreover, based on the design of the middle edge of the broken line profile, the utility model can make the hole wall have better surface roughness.

Of course, the utility model can also have other various embodiments, and those skilled in the art can make various corresponding changes and deformations according to the utility model without departing from the spirit and essence of the utility model, but These corresponding changes and deformations should all belong to the protection scope of the appended claims of the present utility model.

Claims (10)

1. A twist drill for processing holes, comprising a cutter body, characterized in that the cutter body has two helicoids, the two helicoids meet at the axis of the front end of the cutter body, and form a chisel edge at the intersection, each There is a main cutting edge on the spiral body, the main cutting edge includes a front cutting edge and a middle cutting edge, the front cutting edge is connected with the chisel edge, and the front cutting edges on the two spiral bodies have a gap of 72° to 76° between each other. angle, and the length of the chisel edge is 2.3-2.6 mm. 2 . The twist drill according to claim 1 , wherein an additional cutting edge is provided on the outer edge of at least one of the helical bodies, and the additional cutting edge is arranged transversely to the helical direction of the helical body where it is located. 3 . 3. The twist drill according to claim 2, wherein the additional cutting edge has a top angle of 50°-55°. 4 . The twist drill according to claim 1 , wherein the middle cutting edge comprises a multi-segment cutting body, and the multi-segment cutting bodies are connected end to end so that the middle cutting edge has a broken line profile. 5. The twist drill according to claim 4, wherein the middle edge comprises: a first blade body connected to an end of the front blade away from the chisel edge; a second blade body connected to an end of the first blade body away from the front blade; and The third blade body is connected with the end of the second blade body away from the first blade body. 6. The twist drill according to claim 5, wherein the length of the first blade body is L1, the length of the second blade body is L2, and the length of the third blade body is L3, L1 :L2:L3=3:2:1. 7. The twist drill according to claim 6, characterized in that, it has a central axis, and a cross-section perpendicular to the central axis is set, and the front cutting edge has an angle of 35° to 38° relative to the cross-section. angle. 8. The twist drill according to claim 7, characterized in that, the first blade body has an included angle of 22°-26° relative to the cross-section plane. 9. The twist drill according to claim 7, characterized in that, the second blade body has an included angle of 12°-18° relative to the cross section. 10. The twist drill according to claim 7, characterized in that, the third blade body has an included angle of 10°-14° relative to the cross section.