CN2139490Y

CN2139490Y - Bit with long and short cutting lip

Info

Publication number: CN2139490Y
Application number: CN 92236329
Authority: CN
Inventors: 王晓龙
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-10-20
Filing date: 1992-10-20
Publication date: 1993-08-04
Anticipated expiration: 2002-10-20

Abstract

The utility model discloses a bit with a long and a short cutting lips. The spiral axial lines of two helical grooves of the bit with a long and a short cutting lips are separated from a working axial line of a drill tip in parallel. So a long cutting lip and a short cutting lip can be sharpened, the intersection point of the long cutting lip and a work center form the drill tip, and a chisel lip which is not participated in cutting is arranged between the long cutting lip and the short cutting lip. The long cutting lip and the short cutting lip are partially participated in cutting. The utility model has the advantages of favorable centering performance and stability, small axial resistance, comparatively good heat dissipation, easy cutting, reduced abrasion and long service life.

Description

Bit with long and short cutting lip

The utility model relates to a kind of fluted drill, particularly a kind of off-axis heart twist shape length cutting edge drill bit.

At present, at the standard spiral bit that the metal cutting processing industry is used, though have many good qualities, in long-term practice, still there are many weak points in the standard fluted drill:

1, the standard fluted drill is that it is inaccurate to feel relieved with chisel edge centering, lacks centering stability; The chisel edge anterior angle is a negative value, and in working angles, chisel edge is in the state of scraping that squeezes, and axially drag is big; A large amount of heat in metal cuttings have worsened condition of work, have reduced the service life of drill bit.

2, because of chip curling band broad, shared volume is big, stops up helicla flute easily, makes chip removal unfavorable, thereby causes cooling fluid to be difficult for being filled on the cutting edge, makes heavy wear in the drill bit high temperature, has also influenced cutting speed simultaneously.

3, the machining accuracy of standard fluted drill is low, and the surface roughness of hole wall is also very low, and the workpiece of having relatively high expectations for hole wall precision and roughness needs secondary fine finishining.

4, anterior angle is less, and the main cutting edge sharpness is relatively poor in the cutting, and is not too smooth in the cutting.

The purpose of this utility model will provide a kind of centering accurate, stable exactly, and axially drag is little, cutting is smooth, chip removal is smooth, and service life is than long off-axis heart twist shape length cutting edge drill bit.

Realize the utility model at first with the axis of screw of two spiral fluted axis of screw skew primary standard fluted drills of fluted drill, be about to originally axis of operation and the axis of screw totally one axis separate two parallel axis.The axis of screw of primary standard fluted drill is an axis of operation of the present utility model, and the axis of screw of the present utility model is for forming the axis of twisted shape.In sharpening, the cutting tip of off-axis heart twist shape is two main cutting edges that one is long and the other is short, promptly long cutting edge and short cutting edge.Long cutting edge two in the heart at work intersects at work centre with camber line respectively, thereby forms the location apex point, and its purpose is exactly to overcome the bad problem of chisel edge centering.Short cutting edge is a camber line, its end is connected with long cutting edge by the chisel edge that is lower than long cutting edge, and end intersects all sharpenings of formation with front cutting edge in addition, and long cutting edge one end is connected with short cutting edge by chisel edge, end intersects all sharpenings of formation with front cutting edge in addition, constitutes tricuspid two-edged form.Be the diameter of working portion at chisel edge mid point d/3(" d ") do not participate in cutting in the scope, can significantly reduce the axial drag in the working angles like this.And all participate in cutting at the extraneous long cutting edge of chisel edge mid point d/3, short cutting edge.

The material that length is cut the employing of front edge drill bit is W18Gr4V or W9Cr4V2, and its quenching hardness is HRC62-68.

Owing to adopt off-axis heart twist shape structure, avoided the deficiency of the chisel edge centering of standard fluted drill, the apex point centering that is formed centrally at work with long cutting edge has good centering accuracy and stability, axial drag when having reduced cutting significantly, the length cutting edge comes down to part and participates in cutting in working angles, article two, helicla flute can not filled up by smear metal, and the smear metal band of participating in cutting because of part is not wide, and helicla flute is stopped up.Can avoid can not injecting the cutting position because of cooling fluid causes the temperature rising to increase the rate of wear of cutting edge.The chisel edge part is not participated in cutting, and it just plays the connection effect in the length cutting edge sharpening process, and chisel edge partly is lower than the length cutting edge and does not participate in cutting, can not increase axial drag.The anterior angle of participating in the length cutting edge of cutting increases, not only can make cutting edge sharp, cutting easily smoothly, can not influence cutting speed yet, because length cutting edge and front cutting edge form two cutting points, can carry out micro cutting to hole wall, so not only can improve the roughness of hole wall, also have and stablize guide effect preferably.

Below in conjunction with accompanying drawing the utility model is described in further details.

Fig. 1 looks schematic diagram for master of the present utility model.

Fig. 2 looks schematic diagram for the left side of the utility model Fig. 1.

Fig. 3 is an overall schematic of the present utility model.

Fig. 4 is a length cutting edge section enlarged diagram of the present utility model.

With reference to Fig. 3.The utility model is made up of working portion 21, neck 22 and shank 23.Working portion, neck and shank coexist on the axis of operation 20.For the usefulness of emery wheel withdrawing, shank is the retained part of drill bit to neck when grinding drill bit, required moment of torsion and axial force when being used for transmitting boring.Neck is identical with the standard fluted drill with shank.

With reference to Fig. 1, Fig. 2.Working portion 21 is an off-axis heart twist shape, and promptly the axis of screw 16 of two of working

portion helicla flutes

4,13 is parallel to axis of operation 20 determining deviation that offsets to one side.Be projected as (being Fig. 2) on the round view at working portion, work centre 3 overlaps with axis of operation 20.Long cutting edge is to form by the rake face at back knife face 2 and helicla flute 13 places is crossing, and long cutting edge, 1,11 heart both sides at work intersects at work centre 3 with camber line 1,11 respectively, forms location apex point 17.The difference of location apex point and standard fluted drill is: the standard fluted drill is with sword centering, centering accurately and stability very poor, and location of the present utility model apex point is one pointed, centering accurately can sideslip, the stability height.Be projected as on the round view wherein central lines of long cutting edge and center line 7,12 at working portion 21.

The rib sword that the rake face at back knife face 9 and helicla flute 4 places intersects is short cutting 5, short cutting edge 5 is a camber line, be projected as on the round view being projected as a straight line and being parallel to the projection of long cutting edge of short cutting edge 5, long cutting edge and lack between the cutting edge spacing is arranged at working portion.

Chisel edge 8 is in the solid position between long cutting edge 1,11 and the short cutting edge 5, and the mid point of chisel edge 8 overlaps with the axis of screw 16.Promptly be in the center of helicla flute helical centre 6,10.The vertical range of chisel edge 8 mid points and center line 12 be working portion 21 diameter d 1/6.Chisel edge mid point d/3 scope is not for participating in the cutting position, and long cutting edge in this scope and short cutting edge all are lower than extraneous long cutting edge and short cutting edge.Such purpose has avoided chisel edge to participate in cutting exactly, produces the disadvantage of big axial drag and a large amount of heat in metal cuttings, and at this, chisel edge only plays long cutting edge and is connected sword naturally with short cutting edge in sharpening.Long cutting edge and short cutting edge intersect with secondary cutting blade 14,19 respectively, form two cutting points 15,18, two cutting points 15,18 are in postpone in apex point 17 cutting positions, in use promptly, earlier by apex point 17 location, cutting point 15,18 enters working angles then, and the purpose of cutting point 15,18 is the effect of smoothing hole wall also to play certain guide effect simultaneously.If long cutting edge is decided to be f with the parallel distance of lacking cutting edge, the mid point of chisel edge 8 should be in center line 6 places, i.e. f/2 place so.

In sharpening, must note the long cutting edge and the short cutting sharpening of chisel edge mid point d/3 scope must be lower than extraneous long cutting edge and short cutting edge.Two cutting points 15,18 should be worn into circular arc.

Claims

1, a kind of length cutting edge drill bit is made up of working portion 21, neck 22 and shank 23, it is characterized in that:

A. working portion 21 is an off-axis heart twist shape, and promptly the axis of screw 16 of two of working portion helicla flutes 4,13 is parallel to axis of operation 20 determining deviation that offsets to one side, and is projected as on the round view at working portion, and work centre 3 overlaps with axis of operation 20,

B. the crossing rib sword of the rake face at back knife face 2 and helicla flute 13 places is long cutting edge 1,11, the long cutting edge heart 3 both sides at work intersects at work centre 3 with camber line 1,11 respectively, forms location apex point 17, is projected as on the round view at working portion, long cutting edge and central lines wherein

C. the crossing rib sword of the rake face at back knife face 9 and helicla flute 4 places is short cutting edge 5, short cutting edge 5 be a camber line, is projected as on the round view at working portion, lacks being projected as a straight line and being parallel to the projection of long cutting edge of cutting edge 5, between long cutting edge and the short cutting edge spacing is arranged

D. between long cutting edge 1,11 and the short cutting edge 5 chisel edge 8 is arranged, chisel edge 8 is in the solid position of the axis of screw 16, the mid point of chisel edge 8 overlaps with the axis of screw 16, the vertical range of chisel edge 8 mid points and center line 12 be working portion 21 diameter d 1/6, cut the position for not participating in the chisel edge mid point d/3 scope

E. long cutting edge and short cutting edge intersect with front cutting edge 14,19 respectively, form two cutting point 15,18, two cutting edges 15,18 and are in postpone in apex point 17 cutting positions.