CN112139566B

CN112139566B - U-shaped drill

Info

Publication number: CN112139566B
Application number: CN202011033037.6A
Authority: CN
Inventors: 龙港; 张高; 李鹏辉; 赵庆军; 夏科尧; 夏翻翻
Original assignee: Centech Eg Co ltd
Current assignee: Centech Eg Co ltd
Priority date: 2020-09-27
Filing date: 2020-09-27
Publication date: 2023-02-10
Anticipated expiration: 2040-09-27
Also published as: CN112139566A

Abstract

The invention discloses a U-shaped drill, belongs to the field of drill tool products, and provides a U-shaped drill with better cutting and drilling effects; including the handle of a knife, cutting end at the handle of a knife is provided with first cutter body and second cutter body, first end sword that the radial direction of edge handle of a knife extends the setting has on first cutter body, the radial direction that has on the second cutter body along the handle of a knife extends and sets up second end sword, the middle part at first end sword is provided with the first drill point of the axis direction evagination along the handle of a knife, the middle part at second end sword is provided with the second drill point of the axis direction evagination along the handle of a knife, and distance L1 of first drill point apart from the axis of handle of a knife and the distance L2 of second drill point apart from the axis of handle of a knife satisfy following relation: l1 is less than L2. In the cutting process, the first drill point and the second drill point form an inner circle and an outer circle with a certain distance L2-L1, so that the cutting and drilling effects of double-layer drill points at different positions can be realized, and the cutting and drilling effects of a U-shaped drill can be effectively improved.

Description

U-shaped drill

Technical Field

The invention relates to a drill bit, in particular to a U-shaped drill.

Background

U-drill is one of the commonly used drill bits for machining drill holes. In a conventional U-shaped drill, a drill tip structure is generally disposed at the center of a cutting end to improve the cutting and drilling effect. However, the effect of cutting and drilling is not very desirable because the drill tip is only provided at the center. In addition, after the traditional U drill is drilled and formed, a reamer is often required to be additionally used for finish machining of the hole, so that the machining precision and the surface roughness of the hole wall are improved; therefore, the processing procedure is long, time-consuming and laborious.

Disclosure of Invention

The invention aims to provide a U-shaped drill with better cutting and drilling effects.

The technical scheme adopted by the invention for solving the technical problems is as follows: u bores, including the handle of a knife, the one end of handle of a knife is the cutting end, cutting end at the handle of a knife is provided with first cutter body and second cutter body, first cutter body and second cutter body are central symmetric distribution along the axis of handle of a knife and set up, have the first end sword that extends the setting along the radial direction of handle of a knife on first cutter body, radial direction that has on the second cutter body along the handle of a knife extends and sets up the second end sword, be provided with the first drill point of the axis direction evagination along the handle of a knife at the middle part of first end sword, be provided with the second drill point of the axis direction evagination along the handle of a knife at the middle part of second end sword, and distance L1 of first drill point apart from the axis of handle of a knife and the distance L2 of the axis of second drill point apart from the handle of a knife satisfy following relation: l1 is less than L2.

Further, the method comprises the following steps: first end sword and second end sword constitute by drill point portion and flat cutting portion, and drill point portion includes that both sides are for the drill point that the oblique sword of the axis slope of handle of a knife and the oblique sword junction of both sides formed, and flat cutting portion includes the tip flat sword that the axis of perpendicular to handle of a knife set up, and the one end of drill point portion extends to the axis of handle of a knife, and the other end of drill point portion is connected with the one end of tip flat sword, and the other end of tip flat sword extends to the periphery border of the cutting end of U brill.

Further, the method comprises the following steps: the length a of the end flat blade of the first end blade is equal to the length b of the end flat blade of the second end blade, and the sum of the lengths of the end flat blades of the first end blade and the second end blade accounts for 20% -30% of the drill diameter D of the U drill.

Further, the method comprises the following steps: the positions of the first drill point and the second drill point satisfy the following formula: 2 (L1 + L2) = D-a-b.

Further, the method comprises the following steps: l1=0.125 (D-a-b); l2=0.375 (D-a-b).

Further, the method comprises the following steps: the flat edge part also comprises a peripheral side flat edge which is arranged parallel to the axis of the tool holder, and the peripheral side flat edge is formed by extending an end flat edge to the peripheral edge of the cutting end of the U-shaped drill and bending the end flat edge.

Further, the method comprises the following steps: the first end blade and the second end blade form a step difference h along the axis direction at the axis position of the tool holder.

Further, the method comprises the following steps: the convex heights H of the first drill point and the second drill point are equal.

Further, the method comprises the following steps: the cutter handle comprises a first mounting arm and a second mounting arm, the first mounting arm and the second mounting arm are arranged along the axis of the cutter handle in a centrosymmetric manner, the first cutter body is mounted on the first mounting arm, and the second cutter body is mounted on the second mounting arm; two chip flutes are formed between the first mounting arm and the second mounting arm along the circumferential direction of the tool shank.

Further, the method comprises the following steps: an inwardly concave arc-shaped enlarged portion is provided at the inner end of each chip pocket.

The beneficial effects of the invention are: according to the invention, the corresponding first drill point is formed in the middle of the first end edge, the corresponding second drill point is formed in the middle of the second end edge, and the distances between the first drill point and the second drill point from the axis of the tool shank are different, namely L1 is less than L2. After the cutter handle rotates around the axis in the cutting process, the first drill point and the second drill point form an inner circle track and an outer circle track with a certain distance L2-L1, so that the cutting and drilling effects of double-layer drill points at different positions can be realized, and the cutting and drilling effects of the U-shaped drill can be effectively improved. In addition, the positions of the two drill points are arranged to be close to each other and uniformly distributed so as to uniformly distribute the cutting amount of the two cutter bodies during cutting drilling as much as possible and ensure the cutting workload and the load balance of the two cutter bodies. In addition, by arranging the peripheral flat blades, synchronous fine machining on the inner wall of a drilled hole can be realized through the peripheral flat blades in the drilling process, the condition that two or more kinds of drilling tools are needed to be machined in the past can be realized by only one drilling tool, the drilling quality can be effectively improved, the machining effect similar to reaming is realized, the hole machining workload can be reduced, and the machining efficiency is improved. In addition, the chip removal effect of the chip groove can be further improved by arranging the corresponding arc-shaped enlarged part at the inner end of the chip groove.

Drawings

Fig. 1 is a schematic perspective view of a specific example of a U-drill according to the present invention;

FIG. 2 is a schematic view of a cross-section of the middle of the mounting arm of the U-drill of FIG. 1;

FIG. 3 is a front view of FIG. 1;

FIG. 4 is a side view of the cutting end side of the U-drill of FIG. 1;

FIG. 5 is a schematic view of an end edge of the cutting end of the U-drill of the present invention;

FIG. 6 is the view of FIG. 5 with the second end edge mirrored to the first end edge side relative to the axis of the shank;

FIG. 7 is an enlarged view of a portion A of FIG. 4;

labeled as: the cutter comprises a cutter handle 1, a first cutter body 2, a second cutter body 3, a first end blade 4, a second end blade 5, a first drill tip 6, a second drill tip 7, a drill tip part 8, a flat blade part 9, an inclined blade 10, an end flat blade 11, a peripheral flat blade 12, a first mounting arm 13, a second mounting arm 14, a chip groove 15 and an arc-shaped enlarged part 16.

Detailed Description

The invention is further described with reference to the following figures and detailed description.

It should be noted that, if directional indications are used in the present invention, such as terms of directions and orientations of up, down, left, right, front and back, the terms are used to facilitate description of relative positional relationship between members, and an absolute position that is not a positional relationship between related members and members is specifically used only to explain a relative positional relationship between members and a motion situation, etc. in a specific posture, if the specific posture is changed, the directional indication is changed accordingly.

The U-shaped drill comprises a tool shank 1, one end of the tool shank 1 is a cutting end, a first tool body 2 and a second tool body 3 are arranged at the cutting end of the tool shank 1, the first tool body 2 and the second tool body 3 are distributed along the axis of the tool shank 1 in a central symmetry manner, a first end blade 4 extending along the radial direction of the tool shank 1 is arranged on the first tool body 2, a second end blade 5 extending along the radial direction of the tool shank 1 is arranged on the second tool body 3, a first drill tip 6 protruding outwards along the axis direction of the tool shank 1 is arranged in the middle of the first end blade 4, a second drill tip 7 protruding outwards along the axis direction of the tool shank 1 is arranged in the middle of the second end blade 5, and the distance L1 between the first drill tip 6 and the axis of the tool shank 1 and the distance L2 between the second drill tip 7 and the axis of the tool shank 1 satisfy the following relations: l1 is less than L2.

Through setting the corresponding position relation L1 of the first drill point 6 and the second drill point 7 to be less than L2, when the U drill is used for drilling, the U drill rotates around the axis of the tool holder 1, the first drill point 6 and the second drill point 7 form an inner track and an outer track with a certain distance L2-L1, the cutting and drilling effects of double-layer drill points at different positions can be realized, and the cutting and drilling effects of the U drill can be effectively improved. Without loss of generality, the outward protruding heights H of the first drill tip 6 and the second drill tip 7 can be equal; as shown in fig. 6.

More specifically, the invention further provides that the first end edge 4 and the second end edge 5 are both composed of a drilling tip portion 8 and a flat edge portion 9, wherein the drilling tip portion 8 comprises two inclined edges 10 with two sides inclined relative to the axis of the tool holder 1 and drilling tips 6 and 7 formed at the joint of the two inclined edges 10, the flat edge portion 9 comprises an end flat edge 11 arranged perpendicular to the axis of the tool holder 1, one end of the drilling tip portion 8 extends to the axis of the tool holder 1, the other end of the drilling tip portion 8 is connected with one end of the end flat edge 11, and the other end of the end flat edge 11 extends to the outer peripheral edge of the cutting end of the U-drill. Reference is also made in detail to the figures. By the above arrangement, the first drill point 6 and the second drill point 7 formed by the drill point part 8 are also located approximately in the middle area of the cutting end, and at the outer edge of the cutting end are end flat edges 11.

In the above-described configuration in which the cutting edge portion 8 and the flat cutting edge portion 9 are provided, the length a of the end flat cutting edge 11 of the first end blade 4 and the length b of the end flat cutting edge 11 of the second end blade 5 may be equal to each other, and the sum of the lengths of the end flat cutting edges 11 of the first end blade 4 and the second end blade 5 may be 20% to 30% of the drill diameter D of the U-drill. More specifically, on the basis of the above structure, the positions of the first drill tip 6 and the second drill tip 7 are further set to satisfy the following formula: 2 (L1 + L2) = D-a-b; l1=0.125 (D-a-b) may be specifically set; l2=0.375 (D-a-b); reference may be made specifically to the positions or parameter settings shown in fig. 5 and 6. Through the arrangement, the areas corresponding to the drilling tip parts 8 are roughly equally divided by the tracks corresponding to the two drilling tips, so that slag chips generated in the drilling process are more uniform and thinner, and are easier to discharge, and the drilling and cutting effects are ensured.

The flat cutting edge portion 9 of the present invention further includes a peripheral side flat cutting edge 12 provided parallel to the axis of the holder 1, and the peripheral side flat cutting edge 12 is formed by extending from the end flat cutting edge 11 to the outer peripheral edge of the cutting end of the U-drill and bending the same. As shown in fig. 5 and fig. 6, by arranging the circumferential side flat blades 12, in the drilling process, synchronous fine machining on the inner wall of the drilled hole can be achieved through the circumferential side flat blades 12, the condition that two or more kinds of drilling tools are needed to be machined in the past can be achieved by only one kind of drilling tool, the drilling quality can be effectively improved, the machining effect similar to reaming is achieved, the hole machining workload can be reduced, and the machining efficiency is improved. Of course, without loss of generality, the edge corresponding to the peripheral flat edge 12 should protrude from the rest of the tool holder 1, so that the peripheral flat edge 12 can effectively realize the cutting action on the hole wall of the drilled hole.

In the present invention, the first end edge 4 and the second end edge 5 may be further provided with a step h formed along the axial direction at the axial position of the holder 1. As shown in fig. 6. Through the arrangement, the first end edge 4 and the second end edge 5 can form step difference at the axis position of the tool holder 1, so that step drilling can be realized in the drilling and cutting process, namely certain cutting drilling is respectively carried out by the first end edge 4 and the second end edge 5, and certain step difference is kept between the first end edge 4 and the second end edge 5.

In addition, in a general case, the tool holder 1 further includes a first mounting arm 13 and a second mounting arm 14, the first mounting arm 13 and the second mounting arm 14 are arranged along the axis of the tool holder 1 in a centrosymmetric distribution, the first tool body 2 is mounted on the first mounting arm 13, and the second tool body 3 is mounted on the second mounting arm 14; two chip flutes 15 are formed between the first mounting arm 13 and the second mounting arm 14 in the circumferential direction of the tool shank 1. Wherein the first mounting arm 13 and the second mounting arm 14 may be provided as a helical structure, and further the first mounting arm 13 and the second mounting arm 14 may be provided as a substantially quarter fan-shaped structure in a tangential plane perpendicular to the axis of the shank 1, and the corresponding tangential plane of each chip pocket 15 is also a substantially quarter fan-shaped structure. Wherein the chip flutes 15 are channels for discharging chips generated during drilling.

More preferably, in order to increase the chip discharging effect of the chip grooves 15, the present invention further provides a concave arc-shaped enlarged portion 16 at the inner end of each chip groove 15. The specific structure of the arc-shaped enlarged part 16 can be set as shown in the attached drawings, and under the condition of ensuring the structural strength of the U-shaped drill, the arc-shaped enlarged part 16 with larger size can be set as much as possible to improve the chip removal effect.

Claims

The U bores, including handle of a knife (1), the one end of handle of a knife (1) is the cutting end, cutting end at handle of a knife (1) is provided with first cutter body (2) and second cutter body (3), first cutter body (2) and second cutter body (3) are central symmetric distribution along the axis of handle of a knife (1) and set up, first end sword (4) that the radial direction of following handle of a knife (1) extended the setting have on first cutter body (2), radial direction that has on second cutter body (3) along handle of a knife (1) extends and sets up second end sword (5), its characterized in that: the middle part of first end sword (4) is provided with along the first drill point (6) of the axis direction evagination of handle of a knife (1), is provided with along the second drill point (7) of the axis direction evagination of handle of a knife (1) in the middle part of second end sword (5) to the distance L1 of the axis of first drill point (6) apart from handle of a knife (1) and the distance L2 of the axis of second drill point (7) apart from handle of a knife (1) satisfy following relation: l1 is less than L2;

first end sword (4) and second end sword (5) constitute by drill point portion (8) and flat cutting edge portion (9), drill point portion (8) include both sides for oblique sword (10) of the axis slope of handle of a knife (1) and drill point (6) that inclined sword (10) junction of both sides formed, 7), flat cutting edge portion (9) are including tip flat cutting edge (11) that the axis of perpendicular to handle of a knife (1) set up, the one end of drill point portion (8) extends to the axis of handle of a knife (1), the other end of drill point portion (8) is connected with the one end of tip flat cutting edge (11), the other end of tip flat cutting edge (11) extends to the periphery border of the cutting end that the U bored.
2. The U-drill of claim 1, wherein: the length a of the end flat blade (11) of the first end blade (4) is equal to the length b of the end flat blade (11) of the second end blade (5), and the sum of the lengths of the end flat blades (11) of the first end blade (4) and the second end blade (5) accounts for 20% -30% of the drilling diameter D of the U drill.
3. The U-drill of claim 2, wherein: the positions of the first drill point (6) and the second drill point (7) satisfy the following formula: 2 (L1 + L2) = D-a-b.
4. The U-drill of claim 3, wherein: l1=0.125 (D-a-b); l2=0.375 (D-a-b).
5. The U-drill of claim 1, wherein: the flat edge part (9) further comprises a peripheral side flat edge (12) which is arranged in parallel to the axis of the cutter handle (1), and the peripheral side flat edge (12) is formed by extending an end flat edge (11) to the outer peripheral edge of the cutting end of the U drill and bending the end flat edge.
6. The U-drill of claim 1, wherein: the first end cutting edge (4) and the second end cutting edge (5) form a step difference h along the axial direction at the axial position of the cutter handle (1).
7. The U-drill of claim 1, wherein: the convex heights H of the first drill point (6) and the second drill point (7) are equal.
8. The U-drill of any one of claims 1 to 7, wherein: the cutter handle (1) comprises a first mounting arm (13) and a second mounting arm (14), the first mounting arm (13) and the second mounting arm (14) are arranged along the axis of the cutter handle (1) in a centrosymmetric distribution manner, the first cutter body (2) is mounted on the first mounting arm (13), and the second cutter body (3) is mounted on the second mounting arm (14); two chip flutes (15) are formed between the first mounting arm (13) and the second mounting arm (14) in the circumferential direction of the tool shank (1).
9. The U-drill of claim 8, wherein: an inwardly concave arcuate enlargement (16) is provided at the inner end of each flute (15).