CN100571944C

CN100571944C - Throw-away tipped drill

Info

Publication number: CN100571944C
Application number: CNB2007100077450A
Authority: CN
Inventors: 泷口正治
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 2003-03-05
Filing date: 2004-03-05
Publication date: 2009-12-23
Anticipated expiration: 2024-03-05
Also published as: CN101088684A; CN101088685A; CN101088684B; JP4178998B2; JP2004268154A

Abstract

Throw-away tipped drill of the present invention is characterised in that, at the recess that does not contact by formation on the medial surface of aforementioned blade mount pad with the lateral surface of aforementioned throw away chip, pushing portion with the aforementioned recess adjacency is retained as be positioned at rear side than the direction of rotation of the more close drill bit of center line of aforementioned trip bolt, and when being screwed into aforementioned trip bolt, aforementioned pushing portion pushes the lateral surface of aforementioned throw away chip, and aforementioned throw away chip is rotated around aforementioned axis towards the rear side ground of the direction of rotation of drill bit.Can securely blade be fixedly installed on the blade mount pad by the present invention.

Description

Throw-away tipped drill

The application divides an application, and the denomination of invention of female case is throw-away tipped drill, throw away chip and drill main body, and the applying date of female case is on March 5th, 2004, and the application number of female case is 200410008018.2.

Technical field

The present invention relates on the blade mount pad of the groove shape of the leading section that is formed at drill main body, to install removably the throw-away tipped drill of the throw away chip that front end forms the substantially planar of cutting edge (below be referred to as blade).

Background technology

An example of this throw-away tipped drill for example is disclosed in the spy and opens in the flat 11-197923 communique.In this drill bit, on the bottom surface of the blade mount pad of the groove shape of the front end face upper shed of drill main body, form circular hole, on the rear end face of the blade that is installed in the substantially planar on the blade mount pad, setting can be inserted into the axial region in the above-mentioned circular hole.Simultaneously,, week outstanding fastened component is engaged on the notch that is formed on the axial region, blade is installed on the blade mount pad by axial region is inserted in the circular hole.

In this throw-away tipped drill, because only by just can carrying out the installation of blade in the circular hole that the blade axial region is embedded into the blade mount pad, so, the advantage of carrying out the blade exchange operation easily had.But because blade carried out via axial region with only being connected of drill main body, so blade is not high with respect to location (centering) precision of drill main body, the machining accuracy that exists the relative workpiece of drill bit produces dysgenic possibility.

Therefore, the applicant proposed the scheme as Figure 15 and throw-away tipped drill shown in Figure 16 in the past.In this throw-away tipped drill, on the periphery of the drill main body 1 of axes O rotation, forming a pair of chip discharging grooves 2, on the leading section of drill main body 1, form be communicated with these chip discharging grooves 2, the while is at the blade mount pad 4 of the groove shape of front end face 3 upper sheds of drill main body 1.

The blade 5 that front end forms the substantially planar of cutting edge makes the pair of inside face 4A subtend of its one pair of outer side 5A and blade mount pad 4, and is formed in the lateral surface 5A of blade 5 under the state unlimited towards chip discharging grooves 2 of the rake 5B on the part of the front side of the direction of rotation T of drill bit and is fitted on the blade mount pad 4.In addition,, use the trip bolt (among Figure 15, only expressing its axis L) of the leading section that is screwed into drill main body 1, make the pair of inside face 4A of blade mount pad 4 approaching mutually, blade 5 is clamped on the blade mount pad 4 by to traverse the mode of blade mount pad 4.

In the medial surface 4A of blade mount pad 4, on the part of drill bit direction of rotation T front side, form the gathering sill 6 that extends along axes O.In addition, in the lateral surface 5A of blade 5, on drill bit revolves the part of rear side of direction T, form can with the protuberance 7 of gathering sill 6 engagements, by the mutual engaging of these gathering sills 6 and protuberance 7, improve the aligning accuracy of blade 5 with respect to drill main body 1.

As shown in figure 16, trip bolt 8 is screwed in the through hole 9 on traversing the leading section that blade mount pad 4 ground are arranged on drill main body 1 when observing perpendicular to the cross section of the axis of drill main body 1.Through hole 9 spreads all over by one in the front end of blade mount pad 4 drill main bodies 1 divided into two parts (the first leading section 1A) and another (the second leading section 1B) both sides, form in the mode of extending along the radial direction of drill main body 1, its openend is in the outer peripheral face upper shed of the first leading section 1A of drill main body 1, constitute the recess 9A of the head 8A hold the trip bolt 8 that passes through hole 9 simultaneously, the part that is positioned at the second leading section 1B constitutes and is formed on the 9B of negative thread portion that the outer screw section on the side of axial region 8B of the trip bolt 8 that passes through hole 9 screws togather.

Simultaneously, by making trip bolt 8 pass through hole 9, the outer screw section that is formed on this axial region 8B is screwed togather with the negative thread 9B that is formed on the through hole 9, the first leading section 1A and the second leading section 1B strain, the pair of inside face 4A of blade mount pad 4 is approaching mutually.Consequently, the one pair of outer side 5A of blade 5 is pushed on the pair of inside face 4A of cutter blade mount pad 4, and blade 5 is clamped on the blade mount pad 4.Like this, because the rear side of the direction of rotation T of blade 5 (rear end side of drill main body 1) and drill bit from its rear end is supported on the blade mount pad 4, so, in that being holed, workpiece adds man-hour, keep blade 5 in the mode that is pressed on the blade mount pad 4.

But, utilizing above-mentioned trip bolt 8 to keep under the situation of blade 5, the first leading section 1A of drill main body 1 is formed on the recess 9A of the through hole 9 on the first leading section 1A and pushes the ground strain to the inside by the head 8A pushing of trip bolt 8.Relative therewith, the second leading section 1B of drill main body 1 is screwed in the 9B of negative thread portion of the through hole 9 that is formed on the second leading section 1B by the axial region 8B of trip bolt 8, to the inside traction ground strain.Thrust when therefore, the pair of inside face 4A of the blade mount pad 4 one pair of outer side 5A that is pressed to blade 5 respectively goes up becomes inhomogeneous mutually.

Promptly, because the head 8A by trip bolt 8 is pressed into the second leading section 1B generation bigger bending that be screwed into the mode strain of to the inside drawing of the first leading section 1A ratio of inboard mode strain by the axial region 8B of trip bolt 8, so the power of lateral surface 5A of medial surface 4A pushing blade 5 of blade mount pad 4 that the force rate of lateral surface 5A of medial surface 4A pushing blade 5 that is positioned at the blade mount pad 4 of the crooked big first leading section 1A side is positioned at the crooked little second leading section 1B side is big.Therefore, the generation axle of the cutting edge of clamping blade 5, blade 5 problem that precision reduces of shaking forcefully.

In addition, in above-mentioned throw-away tipped drill, only utilize by trip bolt 8 is clamped being installed in the distolateral forward restriction of moving of blade 5 on the drill main body 1, the frictional force that produces between the one pair of outer side 5A of the pair of inside face 4A of blade mount pad 4 and blade 5 is carried out.

Therefore, for example, when carrying out deep hole machining, when on drill main body, applying big load owing to the crooked grade in hole, during broadening, the clamping force of blade 5 reduces between the first leading section 1A and the second leading section 1B, with throw-away tipped drill when workpiece is extracted, sometimes blade 5 can be hooked on the inside in hole, and blade 5 comes off from drill main body 1.

And then in above-mentioned throw-away tipped drill, a pair of rake 5B that is located on the blade 5 that is installed on the blade mount pad 4 becomes the state that opens wide to a pair of chip discharging grooves 2 respectively.Therefore, utilizing by the trip bolt 8 one pair of outer side 5A of the pair of inside face 4A pushing blade 5 of approaching blade mount pad 4 mutually, when being fixedly installed to blade 5 on the blade mount pad 4, blade 5 always is out of shape to direction of rotation front side T (shown in the hollow arrow of Figure 15).

Thereby, part towards drill bit direction of rotation T rear in the one pair of outer side 5A of blade 5 is difficult to be adjacent on the pair of inside face 4A of blade mount pad 4, consequently, not only be difficult to securely blade 5 be kept with respect to blade mount pad 4, and, even as mentioned above, adopt to make protuberance 7 and gathering sill 6 joggled structure, blade 5 is also not enough in the same old way with respect to the aligning accuracy of drill main body 1.

The present invention proposes in view of above-mentioned problem, and its objective is provides a kind of, is utilizing trip bolt, can make this thrust throw-away tipped drill uniformly mutually during with the one pair of outer side of the pair of inside face of blade mount pad pushing blade.In addition, the purpose of this invention is to provide a kind of throw-away tipped drill that can prevent that blade from coming off from drill main body, and the blade and the drill main body that are used for this drill bit.And then, the purpose of this invention is to provide a kind of can utilize trip bolt with blade firmly fix be installed on the blade mount pad of the groove shape of the front end face upper shed of drill main body throw-away tipped drill.In addition, its objective is, a kind of throw-away tipped drill and blade that is used for this drill bit and drill main body of coming off from the blade drill main body of can preventing is provided.

Summary of the invention

In order to achieve the above object; The present invention be a kind of will be that two parts ground is on the blade mount pad of the groove shape of the front end face upper shed of drill main body around the fore-end of the drill main body that axis rotates; With the pair of inside face of its one pair of outer side and aforementioned blade mount pad respectively the chimeric front end in subtend ground form the flat throw away chip that is roughly of cutting edge; And utilize the trip bolt pass the through hole that arranges across with aforementioned blade mount pad to be installed to throw-away tipped drill on the leading section of previous bit main body; It is characterized in that

On the bottom surface of the front of aforementioned axis direction, forming the slit that extends to the rear end side of aforementioned axis direction on the aforementioned blade mount pad, when the front of aforementioned axis direction is observed, aforementioned slots is configured in to be divided in the leading section of two-part previous bit main body by aforementioned blade mount pad with departing from and pushes a side with head by aforementioned trip bolt and compare the part that the axial region of more close aforementioned trip bolt is screwed into.

In this throw-away tipped drill, owing to form from the bottom surface of blade mount pad the slit of distolateral extension backward, so, at the leading section that is divided into two-part drill main body by the blade mount pad during with the close mutually mode strain of the pair of inside face of blade mount pad, these amount of bow separately that are split into the leading section of two-part drill main body increase, and the pushing force during by the one pair of outer side of the pair of inside face pushing blade of blade mount pad increases.

In addition, because slit is configured in to be divided in the leading section of two-part drill main body by the blade mount pad with departing from and pushes a side with head by aforementioned screw and compare, the part that the axial region of more close trip bolt is screwed into, so, the area of section of drill main body that is positioned at the both sides of clamping slit produces difference, and the leading section that the leading section that the head of fastened screw pushes a side and trip bolt axial region are screwed into a side is compared and is difficult to bending.Thereby, be easy to head pushing, the bending of fastened screw are often become the bending that the big head with trip bolt pushes the leading section of a side, be screwed into crooked bending often less, that trip bolt is screwed into the front end of a side with the axial region of trip bolt and set roughly the same amount mutually for, when utilization laid respectively at the one pair of outer side of pair of inside face pushing blade of each the locational blade mount pad that is divided into two-part drill main body, can make its pushing force was mutually uniformly.Thereby, in clamping securely (fastening) blade, can keep the axle precision of shaking of cutting edge.

In addition, in the present invention,, preferably, the angle of cut of the extending direction of the extending direction of aforementioned slots and aforementioned trip bolt is set in 90 ° ± 15 ° the scope when the front of aforementioned axis direction is observed.

In addition; The present invention is a kind of; To be that two-part mode is on the blade mount pad of the groove shape of the front end face upper shed of drill main body around the fore-end of the drill main body that axis rotates; With the pair of inside face of its one pair of outer side and aforementioned blade mount pad respectively the chimeric front end in subtend ground form the flat throw away chip that is roughly of cutting edge; And utilize the trip bolt pass the through hole that arranges across with aforementioned blade mount pad to be installed to throw-away tipped drill on the leading section of previous bit main body; It is characterized in that

In aforementioned blade with the chimeric zone of aforementioned blade mount pad in setting along with from aforementioned front towards rear end side, the rake that stretches out to the outside of thickness direction.

In this throw-away tipped drill, be divided into the mode strain of leading section to push to the inside of two-part drill main body by the blade mount pad, the lateral surface of the blade that clamping and blade mount pad are chimeric by the clamping force of trip bolt.At this moment, in the blade lateral surface with the chimeric zone of blade mount pad in since setting along with from aforementioned front towards rear end side, the rake that stretches out to the outside of thickness direction, so the blade mount pad becomes the front state more outstanding than rear end side.That is, at this state, blade mount pad strain becomes the shape of the rake on the lateral surface of being located at blade, in side view, becomes tapering groove shape.Thereby the restriction blade moves to the drill main body front, prevents that reliably blade from coming off from drill main body.

In this throw-away tipped drill, also can form a plurality of protuberances that extend along axis direction on the blade with on the lateral surface of blade mount pad subtend, in the crest line zone each other of these protuberances, form aforementioned rake, on the medial surface of blade mount pad, form a plurality of can with the gathering sill of aforementioned protuberance engagement, rake and the zone each other, bottom that is positioned at rake and gathering sill are meshing with each other.

In addition, the present invention is a kind of, on the periphery of the drill main body that rotates around axis, form a pair of chip discharging grooves, on the leading section of previous bit main body, form and be communicated with aforementioned a pair of chip discharging grooves, and at the blade mount pad of the groove shape of the front end face upper shed of previous bit main body, on aforementioned blade mount pad, the throw away chip that front end forms the substantially planar of a pair of cutting edge is installed in the following manner, promptly, the one pair of outer side that makes aforementioned blade respectively with the pair of inside of aforementioned blade mount pad in the face of to, make simultaneously in the one pair of outer side of aforementioned blade under the state that in aforementioned a pair of chip discharging grooves, opens wide respectively as a pair of rake towards the part of the front side of the direction of rotation of drill bit, be screwed into trip bolt on the leading section of previous bit main body across by utilizing with aforementioned blade mount pad, make the mutual approaching throw-away tipped drill of pair of inside face of aforementioned blade mount pad, it is characterized in that

At the recess that does not contact by formation on the medial surface of aforementioned blade mount pad with the lateral surface of aforementioned blade, pushing portion with the aforementioned recess adjacency is retained as be positioned at rear side than the direction of rotation of the more close drill bit of center line of aforementioned trip bolt, and when being screwed into aforementioned trip bolt, aforementioned pushing portion pushes the lateral surface of aforementioned blade, and aforementioned blade is rotated around aforementioned axis towards the rear side ground of the direction of rotation of drill bit.

In this throw-away tipped drill, using the one pair of outer side that makes it the pair of inside face clamping blade of mutually close blade mount pad by trip bolt, when being installed to blade on the blade mount pad, by the formation of aforementioned recess and be located at the pushing portion on the medial surface of blade mount pad so that the mode that blade rotates around axis to the rear side of drill bit direction of rotation pushes the lateral surface of blade.Thereby even a pair of rake of blade opens wide to a pair of drain tank of considering to be worth doing earnestly respectively, the blade that is installed on the blade mount pad can be with not outstanding around the mode that axis rotates to the drill bit direction of rotation yet.Thereby, the part towards the rear side of drill bit direction of rotation on a pair of side of blade is adjacent on the pair of inside face of blade mount pad reliably on the part of drill bit direction of rotation front side, can securely blade be fixedly installed on the blade mount pad.

In this throw-away tipped drill, preferably, on the part of drill bit direction of rotation front side, forming the gathering sill that extends along the aforementioned axis direction on the medial surface of aforementioned blade mount pad, simultaneously on the part of the rear side of direction of rotation, form on the lateral surface of aforementioned blade can with the protuberance of aforementioned gathering sill engagement, these gathering sills and protuberance are meshing with each other.

In this throw-away tipped drill, utilize the protuberance of intermeshing blade and the gathering sill of blade mount pad to constitute the serration structure.As mentioned above, owing on the hardness medial surface of the part of drill bit direction of rotation rear side and blade mount pad, be adjacent to reliably on the one pair of outer side of blade towards the part of drill bit direction of rotation front side, so, the protuberance and the gathering sill that are formed on these parts are adjacent to very close to each otherly reliably.Thereby, can improve the aligning accuracy of blade with respect to drill main body.

In addition, blade of the present invention is a kind of blade that is installed on the throw-away tipped drill of the present invention, it is characterized in that, with the chimeric zone of aforementioned blade mount pad in be provided with along with from aforementioned front towards rear end side, the rake that outside thickness direction, stretches out.

In this blade, the gradient of rake be preferably from 0 ° 01 ' to 3 °.When this gradient less than 0 ° of 01 ' time, the leading section deflection of drill main body is few, keeps the power deficiency of blade.On the other hand, when this gradient surpassed 3 °, the inclination of rake was excessive, does not catch up with the distortion of drill main body, and drill main body and blade can not fully be adjacent to, and the confining force of blade descends.Therefore, this gradient preferably 0 ° 01 ' to 3 ° scope.

In addition, in this blade, on leading flank, form a plurality of protuberances that extend, engage with the blade mount pad of previous bit main body simultaneously along the aforementioned axis direction, aforementioned rake is set in the crest line that is positioned at these protuberances zone each other.

In addition, drill main body of the present invention is a kind of drill main body that is used for throw-away tipped drill of the present invention, it is characterized in that, on the bottom surface of the front of aforementioned axis direction, cutting out the slit that extends towards the rear end side of aforementioned axis direction on the aforementioned blade mount pad.

In this drill main body, by form slit on the bottom surface of the blade mount pad of drill main body, the strain of the leading section of the drill main body of this blade mount pad of clamping, subtend becomes and is easy to, and can utilize drill main body to carry out the maintenance of blade reliably.

Description of drawings

Fig. 1 is the side view of the throw-away tipped drill of expression first kind of form of implementation of the present invention.

Fig. 2 is the front end face figure of the throw-away tipped drill of Fig. 1.

Fig. 3 be along the A direction of Fig. 1 to view.

Fig. 4 is the profile along the B-B direction of Fig. 1.

Fig. 5 is the side view that expression is installed to the example of the blade on the throw-away tipped drill of the present invention.

Fig. 6 A is that the major part of the variation of slit in the throw-away tipped drill of expression first kind of form of implementation of the present invention is amplified key diagram.

Fig. 6 B is that the major part of the variation of slit in the throw-away tipped drill of expression first kind of form of implementation of the present invention is amplified key diagram.

Fig. 7 is the profile of variation of the throw-away tipped drill of expression first kind of form of implementation of the present invention.

Fig. 8 is the profile of variation of the throw-away tipped drill of expression first kind of form of implementation of the present invention.

Fig. 9 is the profilograph of the throw-away tipped drill part of expression second kind of form of implementation of the present invention.

Figure 10 is the part profilograph that expression is installed to the example of the blade on the throw-away tipped drill of second kind of form of implementation of the present invention.

Figure 11 is the side view that expression is installed to the variation of the blade on the throw-away tipped drill of second kind of form of implementation of the present invention.

Figure 12 is the front end face figure of the throw-away tipped drill of the third form of implementation of the present invention.

Figure 13 is the front end face figure of the throw-away tipped drill variation of expression the third form of implementation of the present invention.

Figure 14 is the side view that expression is installed to the example of the blade on the throw-away tipped drill of the present invention.

Figure 15 is the front end face figure of example of the throw-away tipped drill of expression prior art.

Figure 16 is the profile of example of the throw-away tipped drill of expression prior art.

The specific embodiment

Below, with reference to description of drawings form of implementation of the present invention.

Fig. 1～Fig. 5 represents first kind of form of implementation of the present invention.

Drilling rod afterbody (omitting among the figure) undergauge that the drill main body 10 of the throw-away tipped drill of this form of implementation is integrally formed with respect to side in its back-end, as its integral body, constitute rotate around axes O, be the multistage cylindric of center with the axes O.

On the front periphery partly of drill main body 10, be formed on a pair of chip discharging grooves 12 of front end face 11 upper sheds of drill main body 10, this drain tank 12 is at the mutual opposition side of clamping axes O, forms helical form in the mode of reversing along with the rear side that advances towards the rear end side of axes O to the direction of rotation T of drill bit.

In addition, on the leading section 13 of drill main body 10,, be formed on the front end face upper shed of drill main body 10 in the mode of extending along the radial direction of drill main body 10, at the blade mount pad 14 of the recessed groove shape of rear end side.

This blade mount pad 14 comprises: towards the front of axes O direction, the bottom surface 14A vertical with axes O; When holding up, be parallel to each other and pair of inside face 14B parallel with axes O, that intersect with the front end face 11 of drill main body 10 from bottom surface 14A; When observing, as shown in Figure 3, be " コ " sub-shape towards the front end face opening of drill main body 10 along the side of bottom surface 14A and medial surface 14B.

In more detail, blade mount pad 14 forms the face towards drill bit direction of rotation T front side of chip discharging grooves 12 front by the radial direction otch along drill main body 10 on the leading section 13 of drill main body 10, on the both end sides part of its bearing of trend M (above-mentioned radial direction), be communicated with chip discharging grooves 12 respectively.

Promptly, the a pair of outer circumferential side end of the both end sides that is positioned at bearing of trend M of bottom surface 14A is faced the outer peripheral face of drill main body 10 respectively, relative therewith, the a pair of periphery of the both end sides that is arranged in bearing of trend M of pair of inside face 14B is from the end, has only one towards the outer circumferential side end face of drill bit direction of rotation T front side outer peripheral face to drill main body 10, another outer circumferential side end can not reach the outer peripheral face of drill main body 10, towards the wall towards the rear side of drill bit direction of rotation T of chip discharging grooves 12.

In addition, blade mount pad 14 by the groove shape is formed on the leading section 13 of drill main body 10, the leading section 13 of drill main body 10 is divided into the first leading section 13A and second leading section 13B two parts, the bottom surface 14A of blade mount pad 14 is between these the first leading section 13A and the second leading section 13B, and, one among the pair of inside face 14B of blade mount pad 14 is positioned at the first leading section 13A side, and another among the pair of inside face 14B is positioned at the second leading section 13B side.

On the leading section 13 of drill main body 10, as shown in Figures 3 and 4, the through hole 20 along the radial direction extension of drill main body 10 that intersects with blade mount pad 14 is set.This through hole 20 connects leading sections 13, and the two ends of the L of its bearing of trend are respectively in the outer peripheral face upper shed of the outer peripheral face and the second leading section 13B of the first leading section 13A.

Through hole 20 is identical with blade mount pad 14, form in the mode of extending along the radial direction of drill main body 10, its bearing of trend L as shown in Figure 4, when the front of axes O direction is observed, not parallel with direction (the width N of blade mount pad 14) perpendicular to the bearing of trend M of blade mount pad 14, tilt with the angle of regulation with respect to the width N of blade mount pad 14.Promptly, when the bearing of trend L of through hole 20 observes from the front of axes O direction, with width N, form (the angle α of the width N of the bearing of trend L of through hole 20 and blade mount pad 14 being set in the scope of 0 °＜α≤3 °) to the tilt mode of an angle [alpha] (0 °＜α≤3 °) of drill bit direction of rotation T front side with respect to the blade mount pad 14 by axes O.

In through hole 20, the part that is positioned at the first leading section 13A is by from the outer peripheral face of the first leading section 13A recess 21 with certain radially axes O direction depression, and be connected with this recess 21, extend, constitute in the hole portion 22 of the medial surface 14B of blade mount pad 14 upper shed with the certain interior radially axes O side less than the internal diameter of recess 21, the coupling part of recess 21 and hole portion 22 constitutes makes its internal diameter along with the conical surface 21A of undergauge gradually that advances to the axes O side.

In addition, in through hole 20, the part that is positioned at the second leading section 13B is extended with certain radially axes O direction from the outer peripheral face of the second leading section 13B, is formed in the negative thread portion 23 of the medial surface 14B upper shed of blade mount pad 14.But, in through hole 20, the part that is positioned at the second leading section 13B can be not yet in the outer peripheral face upper shed of the second leading section 13B.

And then in this form of implementation, in blade mount pad 14, on the bottom surface 14A of the front of axes O direction, the slit 17 that extends to the rear end side of axes O direction forms abreast with axes O.The both ends of the surface of the bearing of trend K of this slit 17 (bearing of trend of slit 17 when the front of axes O direction is observed) are to the wall of chip discharging grooves 12, and consequently, slit 17 is communicated with these chip troughs 12.

Slit 17 as shown in Figure 4, when the front of axes O direction is observed, do not extend along the radial direction of drill main body 10, to compare more mode with the first leading section 13A near the second leading section 13B, depart from specify offset X configuration from axes O, that is, the distance between the bearing of trend of slit 17 (along the bearing of trend of slit 17, the line of the width central authorities by slit 17) K and the axes O is an offset X.

In addition, as shown in Figure 4, observe, the angle of the bearing of trend K of slit 17 and the bearing of trend of through hole 20 (passing the bearing of trend of the trip bolt of describing later 40 of this through hole 20) L is set at about 90 ° from axes O direction front.

And then, the bottom 17A of slit 17 be with a pair of wall of the mutual subtend that constitutes this slit 17 each other along slip, to the recessed cross section semicircle arcuation of the rear end side of axes O direction.

In addition, the degree of depth Y1 of slit 17 (the bottom 17A from the bottom surface 14A of blade mount pad 14 to slit 17 end, along the length of axes O direction) is set in the scope of 3mm～15mm, the width Y2 of slit 17 (constitute slit 17 mutual subtend a pair of wall each other, along the length of the direction vertical with the bearing of trend K of slit 17) be set in the scope of 0.1mm～1mm.

On the front end face 11 of drill main body 10, form front end face 11 and main body side thinning face 11A that the thinning face 31A of the described blade 30 of mode and back of the crest line portions cut that intersects towards the wall of drill bit direction of rotation T rear side in the chip discharging grooves 12 is coupled together.In addition, the pair of inside face 14B of the blade mount pad 14 that intersects with the front end face 11 of drill main body 10 also intersects with described main body side thinning face 11A.

In addition, on each of the pair of inside face 14B of blade mount pad 14, with along the direction vertical, form a plurality of gathering sills 15 that extend along the axes O direction in the spaced mode of regulation with axes O.On the other hand, on each described pair of inside face 14B, the part (part that front end and main body side thinning face 11A intersect) that connects main body side thinning face 11A does not form gathering sill 15, is smooth planar.

That is, gathering sill 15 is located at the zone of removing the part that is connected with the rear end side of (be arranged in axes O) main body side thinning face 11A near among the pair of inside face 14B of blade mount pad 14B, promptly is located at the outer circumferential side of pair of inside face 14B drill main body 10 and be formed on zone towards drill bit direction of rotation T front side.

Consequently, as shown in Figure 2, when the front of axes O direction is observed drill main body 10, the intersection crest line portion of pair of inside face 14B and main body side thinning face 11A becomes linearity respectively, and pair of inside face 14B becomes the waveform shape corresponding with the shape of gathering sill 15 with the crest line portion of intersecting of the front end face of removing main body side thinning face 11A.

In addition, on the leading section 13 of drill main body 10, by between a pair of chip discharging grooves 12 with the outer peripheral face otch of drill main body 10, formation from the rear end of drill main body 10 along axes O extend, a pair of cooling agent discharge portion 16 of the front opening of the coolant hole (not shown) of branch halfway, add man-hour holing, through these cooling agent discharge portions 16, to cutting position supply coolant.

On the other hand, the blade 30 that is installed on the blade mount pad 14 forms as shown in Figure 5 pentagonal partially substantially planar roughly by hard materials such as superhard alloys.In addition, by with its part to its substantial middle portion to rear end face 32, with respect to the thickness direction of blade 30 otch obliquely, form the notch 33 that the described trip bolt 40 in back inserts.

The front end face 31 of blade 30 constitutes the isosceles triangle (V font) that advances and back away to outer circumferential side along with from axes O when being installed to blade 30 on the blade mount pad 14.The one pair of outer side 34 of this front end face 31, blade 30 forms cutting edge 35 respectively in the intersection crest line portion of the rake 34A of drill bit direction of rotation T front side.

In addition, on the front end face 31 of blade 30, when being installed to blade 30 on the blade mount pad 14, regional otch by near the part of will be the axes O at the center that is arranged in front end face 31 intersecting to one pair of outer side 34 and rake 34A and part in addition thereof forms a pair of thinning face 31A that the clamping axes O is positioned at mutual opposition side.And then, in the crest line portion of intersecting, form the thinning cutting blade 35A that extends towards the center of front end face 31 (axes O) from the interior Zhou Duan of cutting edge 35 to thinning face 31A and front end face 31.

In addition, with the part of the rake 34A opposition side of one pair of outer side 34, be formed on a plurality of protuberances 36 that extend along the axes O direction when being installed in blade 30 on the blade mount pad 14 along arranging with predetermined distance perpendicular to the direction of axes O.On the other hand, in described one pair of outer side 34, the various piece beyond rake 34A does not form protuberance 36 on the part (front is in the part that thinning face 31A intersects) that is connected on the thinning face 31A, be smooth planar.

Promptly, protuberance 36 is located in the one pair of outer side 34 of blade 30 an opposite side with rake 34A and is formed on to remove and is connected to (when being installed to blade 30 on the blade mount pad 14, be positioned near the axes O position) zone of part on the rear end side of thinning face 31A, promptly be arranged in the outer peripheral face side of pair of inside face 34 drill main bodies 10, towards the zone of drill bit direction of rotation T rear side.

Consequently, when the front of axes O direction is observed the blade 30 that is installed on the blade mount pad 14, as shown in Figure 2, in one pair of outer side 34, rake 34A is linearly respectively with the crest line portion of intersecting of thinning face 31A, and the part in the one pair of outer side 34 beyond the rake 34A constitutes the waveform shape corresponding with the shape of protuberance 36 with the crest line portion of intersecting of the front end face 31 of removing thinning face 31A.

The thickness direction that makes blade 30 with respect to the parallel state of the width N (with the vertical direction of the bearing of trend M of blade mount pad 14) of blade mount pad 14 under, slide to the rear end side of axes O by the blade mount pad 14 with respect to the groove shape on the leading section that is formed on drill main body 10, the blade 30 that will have this structure inserts.In addition, when this blade 30 is inserted, protuberance 36 on the lateral surface 34 that is formed on blade 30 is engaged in the gathering sill 15 on the medial surface 14B that is formed at blade mount pad 14.

Thereby, the bottom surface 14A subtend of the rear end face of blade 30 32 and blade mount pad 14 and being adjacent to.In addition, in the lateral surface 34 of blade 30, rake 34A opens wide and towards the direction of rotation T of drill bit front side to chip discharging grooves 12 respectively, simultaneously in the lateral surface 34 of blade 30 part beyond the rake 34A respectively with the medial surface 14B subtend of blade mount pad 14.

In this case, the part that has formed a plurality of gathering sills 15 among the medial surface 14B of the part that has formed a plurality of protuberances 36 in the lateral surface 34 of blade 30 in the part beyond the rake 34A and blade mount pad 14 subtend mutually under protuberance 36 and gathering sill 15 intermeshing states.In addition, in the part beyond the rake 34A on the lateral surface 34 of blade 30, the smooth planar part of rear end side that connects thinning face 31A in the medial surface 14B of blade mount pad 14, with the smooth planar part subtend that the rear end side of main body side joint thinning face 11A is connected, the thinning face 31A and the main body side joint thinning face 11A that are connected to simultaneously on the front of these smooth planar parts form continuous face.

Simultaneously, with respect on the leading section 13 that is located at drill main body 10, through hole 20 that blade mount pad 14 is intersected in the mode that tilts with respect to its width N, trip bolt 40 runs through the notch 33 that is inserted into the blade 30 in the blade mount pad 14, and the opening towards the outer peripheral face of the first leading section 13A from the through hole 20 runs through.

It is multistage cylindric that trip bolt 40 is, by being positioned at its rear end, having certain external diameter and become roughly columned head 41, and be connected to this head 41 front, to have the one-tenth of the certain external diameter littler than the external diameter of head 41 roughly cylindric and constitute at the axial region 42 that front is formed with outer screw section 43.In addition, the coupling part of head 41 and axial region 42 forms the external diameter make head 41 along with the conical surface 41A of undergauge near front and gradually.

Trip bolt 40 inserts through hole 20 as described above, and the pin thread 43 that is formed on the axial region 42 of trip bolt 40 is screwed on the negative thread 23 that is formed on the through hole 20.Simultaneously, when in the recess 21 that head 41 is received into through hole 20, the mutual subtend of conical surface 21A of the conical surface 41A of head 41 and recess 21.

Simultaneously, by outer screw section 43 further is screwed into negative thread portion 23, conical surface 41A and conical surface 21A are adjacent to, and when effect was pressed into the power of axes O one side with conical surface 21A, outer screw section 43 effects that screw togather with negative thread portion 23 screw threads were with the power of negative thread portion 23 to axes O one side-lining.

Thereby, the first leading section 13A that inside is formed with recess 21 as Fig. 4 upward arrow 1. shown in, and, the second leading section 13B that inside is formed with negative thread portion 23 as Fig. 4 upward arrow 2. shown in, respectively to axes O side strain closely mutually.Thereby the pair of inside face 14B of blade mount pad 14 is pressed to respectively on the one pair of outer side 34 of blade 30 securely, and intermeshing protuberance 36 and gathering sill 15 also are adjacent to securely simultaneously, and blade 30 is installed on the blade mount pad 14.

In addition, as mentioned above, in the throw-away tipped drill of this form of implementation, on the 14A of the bottom surface of blade mount pad 14, form slit 17.Therefore, when for the pair of inside face 14B that makes blade mount pad 14 close mutually, when making the first leading section 13A of drill main body 10 and the second front end 13B strain with trip bolt 40, the fulcrum when the bottom 17A of this slit 17 becomes the strain of these the first leading section 13A and the second leading section 13B.

Thereby the situation when not forming slit 17 is compared, and the fulcrum when the first leading section 13A and the second leading section 13B strain is displaced to the rear end side of axes O direction.Consequently, the described first leading section 13A and the second leading section 13B amount of bow are fully increased, the thrust in the time of can improving the lateral surface 34 with the medial surface 14B pushing blade 30 of blade mount pad 14.

In addition, because the bearing of trend K of slit 17 intersects with about 90 ° angle of the crossing with respect to the bearing of trend L (bearing of trend of trip bolt 40) of through hole 20, so, when utilizing trip bolt 40 to make the first leading section 13A and the second leading section 13B respectively to axes O side strain, described first leading section 13A and the easy strain of the second leading section 13B, the thrust when further improving the lateral surface 34 with the medial surface 14B pushing blade 30 of blade mount pad 14.

In addition, because the cross section of the bottom 17A of slit 17 is to the recessed semicircle arcuation of the rear end side of axes O direction, so it is concentrated to relax the stress that produces when making the first leading section 13A and the second leading section 13B strain with trip bolt 40.In addition, cross sectional shape as the bottom 17A that can relax the concentrated slit 17 of stress, be not limited to the semicircle arcuation, for example, also can consider to adopt as shown in Figure 6A have width than big circular of the width Y2 of slit 17 (along length) or shown in Fig. 6 B, have the width different shapes such as cross section Long Circle bigger equally than the width Y2 of slit 17 perpendicular to the direction of the bearing of trend K of slit 17, but no matter under any situation, preferably the width with bottom 17A is set in below the 5mm.

And then, be set in by degree of depth Y1 in the scope of 3mm～15mm slit 17, the width Y2 of slit 17 is set in the scope of 0.1mm～1mm, and, form the slit 17 of appropriate shape, the amount of bow of the first leading section 13A and the second leading section 13B is increased, the thrust in the time of not only can fully improving the lateral surface 34 with the medial surface 14B pushing blade 30 of blade mount pad 14, and, the impropriety that can not produce the rigidity that undermines drill main body 10.

In addition, in this form of implementation, slit 17 departs to be configured in when the front of axes O direction is observed compares offset X of the more close second leading section 13B ground off-axis O with the first leading section 13A.Thereby for clamping slit 17, be positioned at for the area of the vertical section of the axes O with drill main body 10 of both sides, the area of part that is positioned at the first leading section 13A side is bigger than the area of the part that is positioned at the second leading section 13B side.

Consequently, compress by head 41 with trip bolt 40, make it mode strain to push to the axes O side, usually the often crooked first big leading section 13A becomes and is difficult to bending, and, utilize the pin thread 43 that screws togather with negative thread 23, make it the mode strain to axes O one side-lining, it is crooked easily that the often crooked second little leading section 13B becomes.Thereby, can set the bending of these first leading sections 13A and the bending of the second leading section 13B for roughly the same amount.

Therefore, be positioned at the medial surface 14B of blade mount pad 14 of the first leading section 13A, one side and the thrust when being positioned at a pair of ground lateral surface 34 of medial surface 14B pushing blade 30 of blade mount pad of the second leading section 13B, one side becomes even mutually in utilization, with respect to blade mount pad 14 clamping securely, the precision of the axle of its cutting edge can being shaken remains on very high state with blade 30.

Here, the offset X of slit 17 can suitably be adjusted to accordingly with the different shape of throw-away tipped drill and can set the bending of the first leading section 13A and the bending of the second leading section 13B for roughly the same amount mutually.For example, be 5mm in the degree of depth of slit 17, width is under the situation of 0.7mm, when the outer diameter D (external diameter that the track that cutting edge 35 rotates around axes O constitutes) of cutting edge 35 during for 15mm, preferably, offset X is set in about 0.5mm.In addition, when the outer diameter D of cutting edge 35 is 25mm, preferably, offset X is set in about 0.8mm.The appropriate offset X of slit 17 and the outer diameter D of cutting edge 35 increase basically and increase pro rata.For example, by 1%～10% (preferably with respect to the outer diameter D of cutting edge 35,1%～5%) suitably sets offset X in the scope, can be easy to the bending of the first leading section 13A and the second leading section 13B set for roughly the same amount (in above-mentioned example, the offset X of slit 17 set the outer diameter D that becomes cutting edge about 3%).

In addition, in the throw-away tipped drill of this form of implementation, by one side a plurality of protuberances 36 on the lateral surface 34 that is formed on blade 30 are engaged on a plurality of gathering sills 15 that extend along the axes O direction on the medial surface 14B that is formed at blade mount pad 14, one side is slided blade 30 and insertion to the rear end side of axes O direction with respect to blade mount pad 14, can be easy to blade 30 is installed on the blade mount pad 14.

And then, by being meshing with each other, these protuberances 36 and gathering sill 15 form the result of serration structure, can improve the positioning accuracy of blade 30 with respect to the blade mount pad 14 of drill main body 10, also can keep the machining accuracy of drill bit well to workpiece.

In addition, by forming above-mentioned serration structure, increase the contact area of blade 30 and blade mount pad 14, can obtain to improve the effect of the installation rigidity of blade 30, and, make drill main body 10 around axes O rotate, holing on workpiece adds man-hour, can obtain to suppress the position skew of blade 30, high efficiency is transmitted the effect of the revolving force of drill main body 10 reliably.

In addition, in this form of implementation, the part that is connected on the rear end side of thinning face 31A in the lateral surface 34 of blade 30 is smooth planar, and the part that is connected to the rear end side of main body side thinning face 11A among the medial surface 14B of blade mount pad 14 also is tabular surface.Therefore, the coupling part of the thinning face 31A of blade 30 and main body side edge reconditioning face 11A is linearly when front is observed, and protuberance 36 and the gathering sill 15 serration structure that constitutes waveform shape that is meshing with each other can not appear on the coupling part of thinning face 31A and main body side thinning face 11A.

Thereby, add man-hour in boring, the smear metal that is generated by thinning cutting blade 35 is not easy to be created in the phenomenon that the coupling part of thinning face 31A and main body side thinning face 11A is stopped the process that flows out through thinning face 11A from thinning face 31A.Thereby, can not encourage the friction of smear metal and drill main body 10, or reduce the discharge characteristic of smear metal.

In addition, in this form of implementation, when the front end of axes O direction was observed, into about 90 °, but this angle of the crossing was not limited thereto with the angle of the crossing setting of the bearing of trend K of slit 17 and the bearing of trend L of through hole 20 (bearing of trend of trip bolt 40).For example, shown in variation as shown in Figure 7 and the variation shown in Figure 8, also the angle of the crossing of the bearing of trend L of the bearing of trend K of slit 17 and through hole 20 can be set in 90 ° ± 15 ° the scope.

In variation shown in Figure 7, with when the front end of axes O direction is observed, the angle of the crossing of the bearing of trend K of slit 17 and the bearing of trend L of through hole 20 (bearing of trend of trip bolt 40) forms slit 17 from 90 ° of bearing of trend K to slit 17 towards the mode of the front side inclination angle beta (0 °＜β≤15 °) of drill bit direction of rotation T.

In this variation, because the bearing of trend K of slit 17 tilts as recited above, so, when making the first leading section 13A and the second leading section 13B strain with trip bolt 40,1. the arrow of the first leading section 13A such as Fig. 7 is represented turgidly, and 2. the arrow of the second leading section 13B such as Fig. 7 is represented turgidly, respectively a front side towards drill bit direction of rotation T tilts, and one towards axes O strain closely mutually.

Therefore, the medial surface 14B of blade mount pad 14 can push the lateral surface 34 of blade 30 basically along the width N of blade mount pad 14.Consequently, owing to reliably and securely protuberance 36 and gathering sill 15 are adjacent to, can obtain to keep well the shake effect of precision of the axle of the cutting edge of blade 30.

In the variation of Fig. 8, with when the front end of axes O subtend is observed, the angle of the crossing of the bearing of trend K of slit 17 and the bearing of trend L of through hole 20 (bearing of trend of trip bolt 40) forms slit 17 from 90 ° of bearing of trend K to slit 17 towards the mode of the front side inclination angle beta (0 °＜β≤15 °) of drill bit direction of rotation T.

In this variation, because the bearing of trend K of slit 17 tilts as described above, so, when trip bolt 40 makes the first leading section 13A and the second leading section 13B strain, the first leading section 13A is as 1. the arrow of Fig. 7 is represented turgidly, and the second leading section 13B is as 2. the arrow of Fig. 7 is represented turgidly, respectively a rear side towards the direction of rotation T of drill bit tilts, and one towards axes O direction strain closely mutually.

Therefore, the medial surface 14B of blade mount pad 14 is along with the lateral surface 34 that can roughly push blade near axes O along the rear side of drill bit direction of rotation T.Thereby, by make in two sides that constitute protuberance 36 one with two sides that constitute gathering sill 15 in one firmly be adjacent to, acquisition can keep the effect of the precision of spool shaking of the cutting edge of blade 30 well.

In addition, in this form of implementation, observe from the front of axes O direction, the bearing of trend L of through hole 20 tilts with respect to the width N of blade mount pad 14, but its direction is not limited thereto.For example, the bearing of trend L of through hole 20 also can be parallel with the width N of blade mount pad 14.In this case, the angle of the crossing α of the width N of the bearing of trend L of through hole 20 and blade mount pad 14 is 0 °.

Below, other form of implementation of the present invention is described.In addition, in the following description,, omit its explanation for paying the symbol identical with Fig. 1～Fig. 5 with the part that above-mentioned Fig. 1～form of implementation shown in Figure 5 has same structure and an effect.

Second kind of form of implementation of the present invention is shown in Fig. 9 and Figure 10.In the throw-away tipped drill of this form of implementation, in blade 30 on the zone (being the zone that forms protuberance 36 in this form of implementation) chimeric with blade mount pad 14, as shown in figure 10, be provided with along with from front towards rear end side, the rake 37 that stretches out to the thickness direction outside.In this form of implementation, on the zone between the crest line of adjacency protuberance 36, forming rake 37, the crest line of protuberance 36 is the same with the lateral surface 34 of blade 30, mutually almost parallel.In addition, the gradient of rake 37 from 0 ° 01 ' to 3 °.

Blade 30 usefulness with this structure are installed on the drill main body 10 with first kind of identical step of form of implementation.That is, the thickness direction that makes blade 30 with respect to the parallel state of the width N of blade mount pad 14 under, with respect to the groove shape blade mount pad 14 on the leading section that is formed on drill main body 10, insert by sliding to the rear end side of axes O direction.In addition, when the insertion of blade 30, be formed on protuberance 36 on the lateral surface 34 of blade 30 and be engaged on the gathering sill 15 on the medial surface 14B that is formed at blade mount pad 14.

Simultaneously, trip bolt 40 passed the through hole 20 on the leading section 13 that is arranged on drill main body 10, be screwed in the negative thread portion 23 that is formed on the through hole 20 by the outer screw section 43 on the axial region 42 that will be formed on trip bolt 40, the first leading section 13A and the second leading section 13B are respectively to axes O direction strain closely.Consequently, the pair of inside face 14B of blade mount pad 14 pushes the one pair of outer side 34 of blade 30 respectively securely, and intermeshing protuberance 36 and gathering sill 15 also are adjacent to securely simultaneously, and as shown in Figure 9, blade 30 is installed on the blade mount pad 14.

Here, under the situation of this form of implementation,

protuberance

36 and 15 intermeshing whiles of gathering sill, rake 37 is meshing with each other with the zone each other, bottom that is positioned at gathering sill 15.Particularly, owing in the lateral surface 34 of blade 30 with on the chimeric zone of blade mount pad 14, the rake 37 that stretches out towards rear end side, to thickness direction along with from front is set, so when clamping trip bolt 40, when being installed to blade 30 on the blade mount pad 14, as shown in Figure 9, blade mount pad 14 becomes the state that front is protruded more to the inside than rear end side.

That is, in this state, blade mount pad 14 strains become the shape according to the rake 37 on the lateral surface 34 of being located at blade 30, become tapering groove shape when observing from the side.Thereby restriction blade 30 moves to the front of drill main body 10, prevents blade 30 coming off from blade mount pad 10 reliably.

In addition, on this blade 30, when the gradient of rake 37 less than 0 ° of 01 ' time, the deflection of the leading section of drill main body 10 is few, keeps the power deficiency of blade 30.On the other hand, when this gradient surpassed 3 °, the inclination of rake 37 was excessive, does not catch up with the distortion of drill main body 10, and drill main body 10 and blade 30 can not fully be adjacent to, and the confining force of blade 30 descends.Therefore, this gradient preferably in 0 ° 01 '～3 ° scope (more preferably in 1/100 to 2/100 scope).

In addition, in this blade 30, the groove such as formation such as one pair of outer side 34 grades by grinding blade 30 utilizes the residual zone of this grinding to constitute protuberance 36.Be formed on the rake 37 between these protuberances 36, when forming the grinding of protuberance 36, only need simply grinding tool to be moved with required inclination angle with respect to lateral surface 34, just can form at an easy rate.

In addition, in this form of implementation, enumerated in blade 30, at the example that forms rake 37 on the zone between the crest line of adjacency protuberance 36, but the formation zone of rake 37 is not limited thereto.For example, blade 30 as shown in figure 11 is such, the zone between crest line not only in the adjacency of protuberance 36, also can be with the crest line that comprises protuberance 36 at the lateral surface 34 of interior whole blade 30 as rake 37.

In this case, also be by blade 30 is fitted on the blade mount pad 14, with the trip bolt clamping, blade mount pad 14 strains one-tenth becomes tapering groove shape according to the shape of the rake 37 of blade 30 when observing from the side.Consequently, restriction blade 30 moves to the front of drill main body 10, prevents that reliably blade 10 from coming off from drill main body 10.

And then, also can replace on the zone between the crest line in the adjacency of protuberance 36, forming rake 37, form rake 37 on the crest line of protuberance 36, zone and the lateral surface 34 of blade 30 of order between the crest line of the adjacency of protuberance 36 is the same mutual substantially parallel.Perhaps, also can with in the blade 30 with the chimeric zone of blade mount pad 14 as the tabular surface roughly that does not form protuberance 36, with the whole lateral surface 34 of this general planar as rake 37.

In addition, there is no need in blade 30, to spread all over the chimeric zone of blade mount pad 14 and form rake 37, for example, also can only on the front part zone of blade 30, form this rake.

Figure 12 represents the third form of implementation of the present invention.In the throw-away tipped drill of this form of implementation, in the side end of the pair of inside face 14B of blade mount pad 14 near and the part of the end that intersects of the wall of chip discharging grooves 12 on, with the part that forms a plurality of gathering sills 15 part of the front side of drill-shape direction T (among the medial surface 14B towards) and mode, form the recess 50 that the part with medial surface 14B hollowly constitutes respectively along the bearing of trend M adjacency of blade mount pad 14.

Recess 50, the mode of the end that intersects with the wall that does not reach with chip discharging grooves 12 is formed on the side end of pair of inside face 14B respectively.Consequently, in pair of inside face 14B, connect above-mentioned another the part of outer circumferential side end and left behind as the pushing portion 51 (back description) that compresses lateral surface 34 usefulness of blade 30.

That is, on the pair of inside face 14B in blade mount pad 14, on the two ends of the bearing of trend M of blade mount pad 14, clamping recess 50 ground dispose a plurality of gathering sills 15 and pushing portion 51.In other words, in pair of inside face 14B, with the part that not form a plurality of gathering sills 15 be recess 50, as pushing portion 51.In addition, the length along the bearing of trend M of blade mount pad 14 with pushing portion 51 for example, is set at 1mm.

In addition, as shown in figure 12, observe from the front of axes O direction, pushing portion 51 is with mode and recess 50 adjacency than the position of the more close drill bit direction of rotation of bearing of trend (bearing of trend of through hole 20) the L T rear side of through hole 20.Particularly, under the situation of this form of implementation, using central portion along its bearing of trend M (among Figure 12, the line N that intersects with axes O) under the situation when blade mount pad 14 is cut apart, pushing portion 51 is to be positioned at mode and recess 50 adjacency than the rear side of the more close drill bit direction of rotation of above-mentioned central portion T.

In this form of implementation, blade 30 is to be installed on the drill main body 10 with first kind of same step of form of implementation.That is, the thickness direction that makes blade 30 with respect to the parallel state of the width N of blade mount pad 14 under, with respect to the blade mount pad 14 of the groove shape of the leading section that is formed on drill main body 10, insert by sliding to the rear end side of axes O direction.In addition, when blade 30 inserts, be formed at protuberance 36 on the lateral surface 34 of blade 30 and be engaged on the gathering sill 15 on the medial surface 14B that is formed at blade mount pad 14.

Simultaneously, trip bolt 40 passed the through hole 20 on the leading section 13 of being located at drill main body 10, be screwed in the negative thread portion 23 that is formed on the through hole 20 by the outer screw section 43 on the axial region 42 that will be formed on trip bolt, the first leading section 13A and the second leading section 13B are respectively to axes O direction side strain closely mutually.Consequently, the pair of inside face 14B of blade mount pad 14 (pushing portion 51 correctly says so) pushes the one pair of outer side 34 of blade 30 respectively securely, intermeshing protuberance 36 and gathering sill 15 also are adjacent to securely, and blade 30 is installed on the blade mount pad 14.

In this form of implementation, owing on the pair of inside face 14B of blade mount pad 14, above-mentioned recess 50 is set respectively, so these recesses 50 do not contact with the lateral surface 34 of blade 30, replace this situation, contact with the lateral surface 34 of blade 30 in abutting connection with the pushing portion 51 of recess 50.

As mentioned above, pushing portion 51 is positioned at the position than the rear side of the more close drill bit direction of rotation of the centre line L of trip bolt 40 T when the front of axes O direction is observed.Therefore, when passing through to clamp trip bolt 40, when these pushing portions 51 pushed the lateral surface 34 of blades 30, the blade 30 that is inserted in blade mount pad 14 bore the power of rotating (shown in Figure 12 empty arrow) towards drill bit direction of rotation T rear side, around axes O.

Thereby,, be installed in blade 30 on the blade mount pad 14 and give prominence to rotatably around axes O to drill bit direction of rotation T front side also can be as prior art in even a pair of rake 34A of blade 30 opens wide to a pair of chip discharging grooves 12.Consequently, part towards the direction of rotation T of drill bit rear side is adjacent on the part of the direction of rotation T front side of drill bit among the pair of inside face 14B of blade mount pad 14 reliably, blade 30 can be installed on the blade mount pad 14 securely.

In addition, in this form of implementation, the recess 50 that is respectively formed on a pair of side 14B of blade mount pad 14 forms by the degree of depth with the part depression regulation of medial surface 14B, but recess 50 is not limited thereto.For example, as shown in figure 13, be recessed to form recess 50 by a part to the rear end side of axes O direction with the pair of inside face 14B of blade mount pad 14, shoal gradually to chip discharging grooves 12 sides by the degree of depth that makes its recess 50, pushing portion 51 can be remained on the end that the wall with chip discharging grooves 12 of medial surface 14B intersects.

Put it briefly, can be on the pair of inside face 14B of blade mount pad 14, form the recess 50 of the shape of the rigidity of the leading section 13 that does not undermine drill main body 10, can be residual above-mentioned pushing portion 51 respectively.

In addition, in above-mentioned second and third kind form of implementation, enumerate the example that on drill main body 10, forms slit 17, but also can on drill main body 10, not form slit 17.

In addition, first to the third form of implementation, blade 30 that also can be shown in Figure 5, and be to use as shown in figure 14, in the cutting edge 35 on the front end that is formed at blade 30, will comprise its outer circumference end retreats the interval of regulation as the rear end side to the axes O direction in an interior part the blade 30 of fine finishining sword 35B.Specifically, the length d along the radial direction of drill main body 10 of fine finishining sword 35B is set in the scope of 0.01mm～0.10mm, will distance be set in along the axes O direction from the front end of fine finishining sword 35B to the rear end face 32 of blade 30 from the outer circumference end of cutting edge 35 to rear end face 32 along about the a/3 apart from a of axes O direction.

Hole in the processing utilizing the throw-away tipped drill that is installed on the blade mount pad 14 shown in Figure 14, the cutting edge 35 that is positioned at the front end place of blade 30 in utilization forms in the machining hole on workpiece, can utilize the fine finishining 35B that is in the going-back position place than these cutting edges 35, the inwall of machining hole is carried out fine finishining.Consequently, the surface accuracy of the inwall by formed machining hole.

Claims

1, a kind of throw-away tipped drill, on the periphery of the drill main body that rotates around axis, form a pair of chip discharging grooves, on the leading section of previous bit main body, form and be communicated with aforementioned a pair of chip discharging grooves, and at the blade mount pad of the groove shape of the front end face upper shed of previous bit main body, on aforementioned blade mount pad, the throw away chip that front end forms the substantially planar of a pair of cutting edge is installed in the following manner, promptly, the one pair of outer side that makes aforementioned throw away chip respectively with the pair of inside of aforementioned blade mount pad in the face of to, make simultaneously in the one pair of outer side of aforementioned throw away chip under the state that in aforementioned a pair of chip discharging grooves, opens wide respectively as a pair of rake towards the part of the front side of the direction of rotation of drill bit, be screwed into trip bolt on the leading section of previous bit main body across by utilizing with aforementioned blade mount pad, make the pair of inside face of aforementioned blade mount pad approaching mutually, it is characterized in that

At the recess that does not contact by formation on the medial surface of aforementioned blade mount pad with the lateral surface of aforementioned throw away chip, pushing portion with the aforementioned recess adjacency is retained as be positioned at rear side than the direction of rotation of the more close drill bit of center line of aforementioned trip bolt, and when being screwed into aforementioned trip bolt, aforementioned pushing portion pushes the lateral surface of aforementioned throw away chip, and aforementioned throw away chip is rotated around aforementioned axis towards the rear side ground of the direction of rotation of drill bit.

2, throw-away tipped drill as claimed in claim 1, it is characterized in that, on the part of drill bit direction of rotation front side, forming the gathering sill that extends along axis direction on the medial surface of aforementioned blade mount pad, simultaneously on the part of drill bit direction of rotation rear side, form on the lateral surface of aforementioned throw away chip can with the protuberance of aforementioned gathering sill engagement, these gathering sills and protuberance are meshing with each other.

3, throw-away tipped drill as claimed in claim 1 is characterized in that, in aforementioned throw away chip with on the chimeric zone of aforementioned blade mount pad the rake that stretches out to the thickness direction outside towards rear end side along with from aforementioned front is set.

4, throw-away tipped drill as claimed in claim 3, it is characterized in that, forming a plurality of protuberances that extend along axis direction on the aforementioned throw away chip with on the lateral surface of blade mount pad subtend, on the crest line zone each other of these protuberances, form aforementioned rake, on the medial surface of blade mount pad, form a plurality of can with the gathering sill of aforementioned protuberance engagement, rake and the zone each other, bottom that is positioned at gathering sill are meshing with each other.

5, throw-away tipped drill as claimed in claim 3 is characterized in that, the gradient of aforementioned rake be 0 ° 01 ' to 3 °.

6, throw-away tipped drill as claimed in claim 3, it is characterized in that, on the bottom surface of the front of aforementioned axis direction, forming the slit that extends to the rear end side of aforementioned axis direction on the aforementioned blade mount pad, when the front of aforementioned axis direction is observed, aforementioned slots is configured in to be divided in the leading section of two-part previous bit main body by aforementioned blade mount pad with departing from and compresses a side with head by aforementioned trip bolt and compare the part that the axial region of more close aforementioned trip bolt is screwed into.

7, throw-away tipped drill as claimed in claim 6 is characterized in that, when the front of aforementioned axis direction is observed, with the angle of the crossing of the bearing of trend of the bearing of trend of aforementioned slots and aforementioned trip bolt, is set in 90 ° ± 15 ° the scope.