CN1030093C - Cold headed center vacuum drill bit - Google Patents

Abstract

A drill bit for drilling holes in a work surface including a hard wear-resistant insert and a metal body including a top working surface of an irregular surface configuration having a slot for retaining the hard wear-resistant insert. The body having a metal grain structure substantially parallel with the contour of the body. In a preferred embodiment the body is formed by cold-heading.

Description

Cold headed center vacuum drill bit

The present invention relates to drill bit.More specifically say and the present invention relates to the middle part vacuum drill bit that cold-heading is made.

A drill bit generally is installed in the working end of an elongated hollow drilling rod, and drilling rod is connected with a rotating power source.Drill bit and drilling rod just can be used to hole on a working surface then, and for example boring becomes to hold explosive so that roll bolt to be installed on the cap rock layer of mine inlet.

The drill bit that is fixed in the drilling rod working end comprises that one has the cylinder of top working surface, and an embedding blade of being made by hard wear-resistant material such as Talide is installed on the working surface of top.A pair of dust collection mouth is positioned at the blade below and is communicated with an axial hole that extends by the drill bit bottom.

Because the boring on the rock stratum can produce a large amount of borehole cuttings thing and dust, the dust collection mouth of these smear metal materials on bit body will be taken out through hollow drill pipe then as usual.Adopt a suitable vacuum pump perhaps to select, thereby can force cooling fluid upwards to wash away smear metal material or dust by drilling rod and through collecting a mouthful outflow with smear metal material suction bit body and by hollow drill pipe as another kind.

By on the limited cylindric steel billet material of a size, finishing a series of complicated mechanical operations to make a bit body in the boring of mine inlet top layer for known.More specifically say, get out at the blank center then with expanding an axial hole and make a bit body and become convention by a cylindric steel billet material is provided earlier.Process one or two reaming off-load ring then in the outside of interior axial hole, expand subsequently and radial hole in the hexagon, the both sides of milling blank are to form two flat side surfaces then.Then, the top working surface of blank is processed to a taper, has staggered oblique top face and compressing surface, allows dust and similar item to flow around bit body when going deep into the rock stratum with convenient drill bit.Get out above-mentioned dust collection mouth by side surface then.Below the collection mouth, get out a hole then and for example can press from both sides, so that drill bit is fixed on the drilling rod from 5522 chucks and 9240 steel that Kennametal company obtains so that a fastening devices to be provided.Between oblique top face and compressing surface, processing a transverse groove on the working surface of top diagonally at last, tungsten carbide insert is being fixed on device on the bit body to provide one.

It is complicated making the required machine operations of a bit body, and size, shape and the performance characteristics of the bit body that goes out of discovery meeting limit production.For example, the edge that forms in the flat side surface of machine bit body is generally comparatively sharp-pointed, and this can interfere the taking-up of flowing of air and boring dust.In addition, compare by the bit body of cold-heading molding, can lose more grainiess by the machine bit body with part.Can think, can weaken the structural integrity of drill bit because of machine loses too much metal grain structure from a bit body, thereby be unfavorable for improving the performance of drill bit.Make the required various machine operations of bit body the quite most of of finished product total cost that accounted for.If can find a kind of new method of the manufacturing drill bit that overcomes the prior art defective just very favourable like this.

The effort of making a kind of new drill body is by casting.The bit body that has found that casting can be eliminated the required machining steps of some manufacturing drill bits.Yet the shortcoming of the middle part vacuum drill bit of this casting is very inferior casting globality and intensity, and this can cause the drill bit premature failure.And the middle part vacuum drill bit of these castings also has and relevant expensive of investment casting technique.

As a result, just be necessary to provide a kind of improved technology and design, eliminate machining steps as much as possible so that in the production of bit body, make pottery, and can not sacrifice some necessary engineering properties.

In order to address the above problem, we invent a kind of new design of bit body and make the new technology of bit body.The present invention has eliminated machine bit body side surface with the necessity and the machine top working surface that form flat side surface with expand the necessity that bit body center inner hexagonal hole.The present invention also allows to eliminate and gets out and expand the step that axial hole in and the step of one or two reaming off-load ring of machine.The advantage of eliminating reaming off-load ring is the intensity that has increased bit body.In addition, advantage of the present invention is to make bit body sooner more economically, and line of flow (grainiess) is followed the profile of bit body so the steel bit body intensity of making is higher owing to forge.Machine when bit body according to the present invention shows super toughness with respect to mach bit body and eliminated expansion hexagonal endoporus is sharp to be had, thereby the bit body of a consistency of thickness is provided, and this gives the bit body added strength.Bit body can have roughly uniformly straight warp, or according to another embodiment of the present invention, the relative end of the outer surface of bit body from the top working surface towards bit body is tapered.Its tapering can change as required.

Here used " being tapered " speech means along the length linearity of bit body or non-linear width direction size and reduces.

Preferably adopt low-alloy steel in the present invention, this is owing to can increase the intensity of bit body.Adopt the low-alloy metal, it is more easy to make the further machine of bit body.For example, can process various sizes easily, the simple embedding insert groove of the complexity of position and quantity at the top of bit body.

Other advantage of the present invention is to make bit body have complicated outer body structure now, thereby the air that improves wound drill bit body top working surface flows, and improve drilling operation, and also can make things convenient for now and make the simple structure of various covers economically so that bit body is fixed on the drilling rod.For example, according to one embodiment of present invention, air and material flowed during a tapered bit body provided added strength for the top working surface and improved boring.

Therefore, the object of the present invention is to provide one have one comprise the top working surface bit body the middle part vacuum drill bit and make the method for drill bit.

Drill bit produced according to the invention comprises that hard, wear-resistant embeds blade and a metallic object, metallic object have the top working surface of an irregular surface configuration and one fixedly hard, wear-resistant embed the groove of blade.Bit body is preferably by cold-heading molding, so that a kind of metal grain structure that is roughly parallel to the bit body profile to be provided.Bit body can have roughly diameter uniformly, or according to another embodiment of the present invention, bit body can be tapered the opposite end from the top working surface towards bit body.Its tapering can change as required.

Bit body comprises one by the upwardly extending interior axial hole of bit body one end, at least two are parallel to the bit body extension of central axis in the bit body outside, or the recessed relatively flat side surface of the shape of falling C that splay in one opposite end from the top working surface towards bit body, the dust collection mouth relative with at least two.Each is collected mouth and communicates by a corresponding flat side surface extension and with axial hole.Collect mouthful normally oval-shaped and locate with about miter angle with respect to central axis, collection mouthful also can be circle.The upstanding portion that a pair of section of putting relatively is an arc is being collected extension between the mouth.

Collect mouth and define a pair of transverse bending shoulder of putting relatively at its lower limb.

The top working surface of bit body comprises the oblique compressing surface that oblique top face that staggered the first couple relatively puts is relative with second pair and put.Groove staggered oblique top face and compressing surface between horizontal expansion to hold the embedding blade.

Each oblique top face is the slightly taper of microprotrusion, and the edge is left being directed downwards of central axis and stretched out.Each oblique compressing surface is the recessed concave surface of pie shaped, collect mouthful downwards and stretch out and is connected towards relevant with flat side surface, and with respect to central axis with greater than 20 inclined at inclination angles of spending.

In one embodiment of the invention, baroclining contracts faces down and extends out to and end at the curved edge of collecting mouthful, promoting to improve air, and the flowing of dust and landwaste so that discharge and take out through axial hole.

The method that is had the drill bit of a bit body (comprising the top working surface) by a blank manufacturing one that has a front end and a rear end comprises the cold-heading blank with the moulding bit body, processes a groove then and processing dust collection mouth on drill bit on the working surface of top.

More specifically say, the step that the method for cold-heading comprises is: blank is shaped to even cylinder dimensions, the front end of blank is molded as the truncated cone, stamp out a centering device in the front-end and back-end of blank, the opposite flank that has oblique scalloped shaped stress release surface at least two of the side of blank moulding, moulding top working surface is to form staggered tilted conical end face and tilted conical compressing surface, axial hole concentric with centralising device of moulding.

Punch steps is included in the blank rear end and stamps out one first cannelure, and stamps out second cannelure of a diameter greater than first cannelure in the rear end of blank, and recessed in the front end moulding one of the truncated cone.

Then, perpendicular to central axis between each is to staggered tilted conical end face and tilted conical compressing surface groove of processing holding the embedding blade, and the dust collection mouth that processing communicates with axial hole on bit body.

With reference to accompanying drawing, can more be well understood to further feature of the present invention and other purpose and advantage by following detailed, wherein:

Fig. 1 is the phantom drawing of a drill bit constructed in accordance;

Fig. 2 is the front elevation drawing of a drill bit constructed in accordance;

Fig. 3 is the sectional elevation of the drill bit shown in Figure 2 got along the 3-3 line;

Fig. 4 is the lateral view of a blank, is made according to bit body of the present invention by this blank;

Fig. 5 is the partial sectional view of a drift and rammer Duan Mo, in order to the blank of moulding Fig. 6;

Fig. 6,8 and 13 is lateral views of middle blank one by one, according to bit body of the present invention blank manufacturing thus;

Fig. 7 is the partial sectional view of a drift and rammer Duan Mo, in order to the blank of moulding Fig. 8;

Fig. 9 is the lateral view that blank shown in Figure 8 turns over 90 degree;

Figure 10 is the top view of blank shown in Figure 8;

Figure 11 is the partial sectional view of a upsetting drift and mould, in order to moulding blank shown in Figure 13;

Figure 12 is the partial sectional view that upsetting drift shown in Figure 11 and mould turn over 90 degree;

Figure 14 is the sectional view of the bit body shown in Figure 13 got along the 14-14 line;

Figure 15 is the partial sectional view of a upsetting drift and mould, in order to moulding blank shown in Figure 17;

Figure 16 is the partial sectional view that upsetting drift shown in Figure 15 and mould turn over 90 degree;

Figure 17 is the lateral view of a cold-heading bit body before embedding the formation of blade retention grooves;

Figure 18 is the sectional view along Figure 18-18 bit bodys of being got shown in Figure 17;

Figure 19 is the top view of bit body shown in Figure 17;

Figure 20 is a phantom drawing, shows another embodiment of drill bit constructed in accordance;

Figure 21 is the front elevation drawing of drill bit shown in Figure 20;

Figure 22 and 24 is the lateral views with middle blank one by one of wedge shape side surface;

Figure 23 and 25 is sectional views of bit body shown in the Figure 22 and 24 that is got along 23-23 line and 25-25 line respectively;

Figure 26 is a phantom drawing, shows another embodiment of drill bit constructed in accordance;

Figure 27 is the front elevation drawing of drill bit shown in Figure 26;

Figure 28 is a phantom drawing, shows another embodiment of drill bit constructed in accordance;

Figure 29 is the front elevation drawing of drill bit shown in Figure 28;

Figure 30 is a microphoto, shows the parallel metal grainiess (multiplication factor 6.3X) of polishing area of a part of section of bit body shown in Figure 25.

In the following description, identical reference number is represented identical part.Also have, in the following description, should be noted that this class word as " forward ", " backward ", " making progress ", " downwards ", " inwardly ", " outwards " and similar word are purposes for convenience, and should not be considered to words of limitation.

Referring now to accompanying drawing, Fig. 1,2,20,21 and 26-29 show a drill bit 10, comprise a bit body 14 that has a top working surface 16, one embeds blade 12 is fixed on this top working surface, this drill bit and a drilling rod (not shown) be used comprise on all kinds of stratum irregular, hard, soft, finish probing work on the rock stratum of middle hardness.Drill bit 10 can be installed on the drilling rod by erecting device, as quick connection port portion (not shown) or know known any other the suitable erecting device of this operator.

Bit body 14 comprises a single part that is formed by cold-heading.Because bit body 14 is formed by cold-heading, so the metal grain structure of drill bit preferably is roughly parallel to the profile of bit body.With compare the drill bit that the bit body 14 with parallel metal grainiess can provide a kind of improved strength cost to reduce by the conventional drill of machine manufacturing.

As Fig. 1,2,20,21 and 26-29 shown in, drill bit 10 comprises that one has the slender cylinder 14 of top working surface 16.By an opposite end 15 of bit body 14 upwardly extending be a section be hexagonal in axial hole 18.Interior axial hole 18 preferably has any only section configuration and length limiting an inner sleeve, in order to holding an insertion end of rotating drilling rod with the relation of internal lock, and rotatory force is delivered to drill bit 10 from a drive unit (not shown).

Bit body 14 can have thick-and-thin basically diameter, and as Fig. 1, shown in 2,20 and 21, perhaps in another embodiment of the present invention, bit body can be tapered the opposite end 15 from the top working surface towards bit body, shown in Figure 26-29.Here used " being tapered " speech means along the linear or non-linear size of the length width direction of bit body and successively decreases.

Bit body 14 tapered degree can be different.For example, the length tapering that is about 2 inches bit body 14 15 can change about 0.004 inch from top working surface 16 to the opposite end on diameter.Yet, the flowing of air and material for the intensity that increases the top working surface and during improving probing, 15 to be considered to should be 0.020 inch to the external surface tapering of bit body 14 at least towards the opposite end from the top working surface 16 of bit body.

Bit body 14 comprises a pair of relative dust collection mouth 20, and they are located with about miter angle with respect to the central axis in the bit body 22.Correspondingly, collect mouth 20 and locate along angle direction with respect to central axis 22, and usually with respect to this radial axis centering.Mouthfuls 20 preferably general elliptical shapes.Yet mouth 20 also can have any only shape, for example circular or similar shape.

Dust collection mouth 20 is by what be recessed into, and the flat side surface 24 that is generally the shape of falling C extends.The vertical centre axis 22 that recessed flat side surface 24 is parallel to each other and extends and be parallel to bit body 14, as Fig. 1, shown in 2,20 and 21, perhaps in another embodiment, side surface 24 15 is splayed towards the opposite end from the top working surface 16 of bit body, shown in Figure 26-29.As Fig. 1,2,20,21 and 26-29 shown in, mouthfuls 20 provide a pair of at its lower limb puts relatively, the shoulder 26 of common transverse bending.Because crooked shoulder 26 is formed in the lower limb of the collection mouth 20 of locating with about miter angle with respect to the top of central axis 22, so crooked shoulder preferably provides an edge that has a rear surface 21, this rear surface 18 slopes inwardly downwards and towards the hole, thereby is convenient to make dust or similar item to move on in the hole 18.Shoulder 26 preferably is positioned at the mid point of the axial length of bit body 14.By this layout, it is long-pending that mouth 20 just has greatest cross-section, and be located substantially on the first half of bit body 14.

Bit body 14 also comprises a pair of upstanding portion 28 of putting relatively, and this upstanding portion 28 is integral and supports this top working surface 16 with top working surface 16.Part 28 usually arc on the cross section, and be positioned at perpendicular to comprising the relevant vertical plane that extend on mouthfuls 20 plane of collecting.Part 28 can be parallel, and as Fig. 1, shown in 2,20 and 21, perhaps in another embodiment, part 28 15 can tilt to the opposite end from the top working surface 16 of bit body 14, shown in Figure 26-29.

The top working surface 16 of bit body 14 has an irregular surface texture, and the oblique top face 30 that it is put relatively by staggered the first couple is relative with second pair and oblique compressing surface 32 that put limits.The oblique top face 30 of the top working surface 16 of bit body 14 and compressive surfaces 32 common cooperations allow boring dust and similar item to flow into dust collection mouth 20 and pass through axial hole 18.Here used " irregular surface " is meant a kind of like this surface, promptly from being different by bit body central axis 22 with intersecting the distance of any point of being limited radially being surveyed perpendicular to the point that Plane intersects limited of central axis 22 to the profile by this plane and irregular surface.

As Fig. 1,2,20,21 and 26 and 26-29 shown in, oblique top face 30 is positioned at the opposite flank by the vertical plane of bit body vertical centre axis 22.Oblique top face 30 is slightly tapers of microprotrusion, and along leaving being directed downwards and stretching out of bit body 14 vertical centre axis 22, and provide one to support or support for embedding blade 12.As shown in the figure, oblique top face 30 is with respect to the angle of the upstanding portion 28 of bit body 14 any suitable angle, to prevent bit body top working surface 16 and drilled rock stratum friction engagement.In a most preferred embodiment, oblique top face 30 with respect to the horizontal plane forms the angle of about 25 degree.

Tiltedly compressing surface 32 is positioned at the opposite flank of above-mentioned vertical plane, and one of them surface of each centering is positioned at the same side on plane like this, thereby is merged into top edge, and top edge roughly is positioned at the same general layout that embeds on blade 12 opposite flanks.Tiltedly compressing surface 32 is one roughly to be the spill concave surface of pie shaped, and the top of working surface 16 of leaving bit body 14 is towards collecting mouthfuls 20 and stretch out downwards.In an alternate embodiments, tiltedly compressing surface 32 downwards and extend out to and end at mouthfuls 20 curved edge (Figure 20,21 and 28,29), helping to improve air, dust, flowing of landwaste and similar item and discharge and take out through axial hole 18.

Tiltedly preferably with such location, angle of inclination, promptly this angle is greater than the angle of inclination of oblique top face 30 for compressing surface 32.As shown in the figure, compressing surface 32 is spent greater than 20 with respect to the angle of inclination of central axis, and best angle is 60 degree.The lower limb of each compressing surface 32 and flat vertical side surface 24 adjacency, they cooperate the pipeline as a dust and similar item to make dust flow to collection mouth 20 together.

Dust collection mouth 20 is positioned at the below of oblique compressing surface 32, and the combined width direction size of compressing surface and groove 36 just is substantially equal to the respective transversal size of respective side surface 24 like this.Collect mouthfuls 20 with the top working surface 16 vertical preset distances that separate, dust and similar item quilt automatically measures and leaves compressing surface 32 like this, by side surface 24 and enter dust collection mouth 20.This realizes in one way, so that can not fill up mouthfuls 20, thereby prevents to collect mouthful and puts up a bridge or stop up by the axial hole 18 of drilling rod.

Shown in Figure 17 and 24, the a plurality of staggered end face of the drill bit 10 that forms by cold-heading and the protrusion 34 that compressing surface 30 and 32 defines a horizontal expansion together carry out machine to form a groove or groove 36 to it then, embed blade 12(Fig. 1 in order to hold one, 20,26 and 28).A plurality of staggered end faces 30 and compressing surface 32 preferably have a kind of like this shape and size.In order to when embedding blade 12 cutting rock stratum, side direction and axial support are provided for blade 12.The vertical centre axis 22 that preferably is parallel to bit body in order to the sidewall that holds the groove 36 that embeds blade 12.

Be fixed on that embedding blades 12 in the groove 36 can have platy structure and by a kind of high strength, anti abrasive material is made, this material can be formed by Talide or similar item.Embedding blade 12 can be for good and all or is fixed on separably in the groove 36.As Fig. 1,2,20,21 and 26-29 shown in, " A " shape house formula tungsten carbide blade is fixed in the groove by soldering.Can use or not use such as U.S. Patent No. 4,817,742 disclosed soldering pads will embed the blade soldering on metallic object.

Embedding blade 12 laterally stretches out and stretch out groove 36 two ends one preset distance above collecting mouth 20, so that provide a slit for bit body 14 when drill bit 10 borings.As Fig. 1, shown in 20 and 26 and 28, in general the exposed lateral surfaces 38 of embedding blade 12 is vertically aligned with limiting each respective side surface 24 of collecting mouth 20.By this layout, dust and similar item are led so that farthest be discharged from downwards and outwards on compressing surface 32.In addition, by this layout, the oblique top face 30 of symmetry location and compressing surface 32 provide the rigid material of monoblock basically with integral part 28, so that top working surface 16 has maximum intensity.

As shown in the figure, dust collection mouth 20 and side surface 24 are positioned at the plane that is parallel to drill bit 10 vertical centre axis 22 usually.So, collect mouthfuls 20 location and define particulate dust that the dust collection passage downcuts with continuous metering with oblique top face 30 and side surface 24 and make it to enter and on longitudinal center's axis 22 opposite sides of drill bit 14, be parallel to each other in the collection mouth that extends relatively radially mutually.

The performance of improving of the bit body 14 of the drill bit 10 according to the present invention obtains by a series of cold-heading operations, referring now to accompanying drawing 4-19 and 22-25 it is described.

Beginning, the wire rod of a fixed length can become uniform diameter by a mould pull of preferably being made by carbide alloy.Wire rod can be transfused to cutting station and an ejection on a stock stop then, and is sheared into the suitable blank of length 40, as shown in Figure 4.Blank 40 is the most handy knows the known conventional art manufacturing of this operator, and is made by any only metal, for example coiled material that provides of USX company or the AISI15B35 of bar form, 4140,8630 or 8640 steel.

In cold-heading operation according to the present invention, the size of blank diameter should be less than the diameter of corresponding cold-heading forging die, flow in mould with material during allowing cold-heading, and, should know that blank 40 is available from the cold-heading station to the transmission of cold-heading station after each time continued operation and know the known any means of this operator and realize.

A bit body 14 according to the present invention is to produce by blank shown in Figure 4 40 being sent to the first cold-heading station shown in Figure 5.The cold-heading station comprises a drift 42 and a complementary mold 44.Drift 42 generally is a rigid cylindrical body, and its size can be allocated within the mould 22, and comprises a projection 54 that cylinder is tip-shape at its front end, and its diameter is less than the diameter of mould.Mould 44 generally is a hollow cylinder body, has the antetheca that a rear aperture 48 and has the convex recessed 46 of inside orientation.In operation, blank 40 shown in Figure 4 is pushed die cavity 44 to form a uniform blank of size shown in Figure 6 by drift 42 under pressure.In particular, the front end of blank is processed to the shape of the truncated cone 56, and is rushed out first centralising device shown in cannelure 58 as the rear end of the blank of more abundant description here, with so that blank centering, and makes the cylinder size of blank even.

Then, blank 40 shown in Figure 6 is taken out in mould 44 by a stripper pin 41, and from being sent to second stripper pin 61 and the drift 60 of cold-heading station shown in Figure 7 between stripper pin and the drift 42.

Cold-heading station shown in Figure 7 comprises the open-ended mould 62 of a drift 60 and a complementation.The front end of drift 60 comprise one tip-shape protruding 63, its shape should process second centralising device shown in cannelure 66, this groove extends into the rear end of blank 40.The diameter of mould 62 is substantially the same with mould shown in Figure 5 44, and comprises two triangle projectioies 70 in the front side wall of mould 62, and they form staggered oblique top face 30 and compressing surface 32 in the front end of blank, as Fig. 8, shown in 9 and 10.

In operation, blank shown in Figure 6 is fixed between second stripper pin 61 and the drift 60 in first cannelure 58.Drift 60 and the 3rd demoulding pin 6 cooperate, and force blank 40 to enter the middle part of open-ended mould 62.Shown in Fig. 7-10, front end at blank forms at least two the relative concave side surfaces 24 and the staggered oblique top face 30 and the compressing surface 32 of top working surface 16, on the side surface 24 of blank 40, also be formed with gradually narrow bullet nose or scalloped shaped stress release surface 64, and in the rear end of blank, form just like second centralising device shown in the cannelure 66, its diameter is greater than first cannelure 58.

As Fig. 4,6,8,13,17, shown in 22 and 24, along with the material that forms blank 40 moves, the gradient on tapered nose stress release surface 64 reduces gradually to the direction of leaving the blank front end.Stress release surface 64 preferably is convenient to material and is flowed and prevent stress crack in mould explosion and the blank 40.Then, stripper pin 61 is released blank 40 in mould 62, and stripper pin has a location boss 72 as shown in Figure 7.Positioning boss 72 is preferably formed as one and is recessed into 74 in the top surface of blank 40, help follow-up stripper pin location in cold heading die centering operation subsequently.

Then, blank 40 shown in Figure 8 is sent to next drift 80 shown in Figure 11 and 12 and mould 82.Blank 40 between the 3rd stripper pin 81 and drift 80 in mould 82 centering, it is recessed 74 that the 3rd stripper pin 81 is positioned at, 82 of drifts are positioned at second cannelure 66.In this cold-heading station, the material that forms blank 40 is pushed in mould 82 backward, thereby has further improved the performance of finished product drill bit 10.Mould 82 comprises bossing 68 and two triangle projectioies 88, bossing 68 forms flat side surface 24 on the direct relative side of blank 40, the size of triangle projection 88 greater than the mould 62 of front further to be molded over the staggered oblique top face 30 and the compressing surface 32 of blank front end.Drift 80 is hexagon masts as shown in the figure, has the front end 86 of a truncated cone shape.Hexagon axial hole 18 in drift 80 shown in Figure 11 and 12 and mould 82 moulding, truncated cone shape front end 86 is concentric with second cannelure 66 that is molded on blank 40 rear ends.Second cannelure 66 is preferably and drift 88 is acted on a centering device is provided on the blank 40, thereby further is convenient to moulding Figure 13, the blank of the symmetry shown in 14,22 and 23.

Then, Figure 13, the blank 40 shown in 14,22 and 23 are sent to the next cold-heading station shown in Figure 15 and 16, and wherein axial hole 18 is molded to the required degree of depth, and the top working surface 16 of blank 40 is further limited.Shown in Figure 15 and 16, the size of mould 90 is approaching identical with finished product drill bit 10 with structure, and its size is greater than mould 82.Drift 92 is for having the cylinder rod of a spheric end.Blank 40 between one the 4th stripper pin 91 and drift 92 in mould 90 centering, it is recessed 74 that stripper pin 91 is positioned at, drift 92 is positioned at axial hole 18.Drift 92 and stripper pin 91 cooperate forces blank 40 to enter mould 90, and the stress release of blank surface and axial hole 18 are further extended to Len req like this.

When manufacturing had the blank 40 of inclination upstanding portion 28 and side surface 74, the size of mould 90 was greater than mould 82.When axial hole 18 during by moulding, to have only the material that forms axial hole 18 front portions just to conform to, thereby the blank 40 of a band tapering is provided with mould 90, it 15 enlarges to top working surface 16 from the opposite end.

When manufacturing had the blank 40 of substantially parallel flat side surface 24 and parallel upstanding portion 28, the size of mould 90 was also greater than mould 82.Yet mould 82 has a bigger rear end, and like this, blank 40 just has a tapering when discharging mould 82, and 15 dwindle towards top working surface 16 from the opposite end.Like this, the material that forms axial hole 18 front portions when blank 40 is discharged mould 90 just conforms to mould 90, thereby provides one to have the flat side surface 24 of almost parallel and the blank 40 of parallel upstanding portion 28.

Be molded to the shape of mould 90 and drift 92 at blank 40 after, blank is released by stripper pin 91.From these simple cold-headings operations, Figure 17,18,24 and 25 the bit body that shows 14 are with regard to moulding.

First and second cannelures 58 and 66, recessed 74 and axial hole 18 fits best together so that a kind of device that makes blank 40 centerings in follow-up mould to be provided, the center that drift by making cold-heading station subsequently and mould act on blank guarantees that bit body 14 has uniform size and end face 30 and compressing surface 32 to be formed into correct shape at each cold-heading station around its central axis 22.Do not have centralising device, continuously shaped bit body 14 with irregular top working surface just has difficulty.

As shown in figure 30, be arranged essentially parallel to the profile or the profile of bit body according to the metal grain structure of bit body of the present invention.As the result of parallel metal grainiess, can produce the higher bit body of the intensity of improving toughness.In addition, also can use if desired than previously possible lower alloy steel, machine is more easy like this, and does not need to make blank anneal before cold-heading.

The dust collection mouth 20 of drill bit 10 can be by suitable machine as boring or similar processes.In most preferred embodiment, dust collection mouth 20 with miter angle boring, is generally oval-shaped opening to provide one with respect to middle bobbin thread 22.Collect mouth 20 and be drilled on bullet nose or the scalloped shaped stress release surface 64, so that the inlet that leads to the axial hole 18 of processing in bit body 14 to be provided, the collection mouth passes to mutually with axial hole 18 and allows with vacuum collecting dust and similar item like this.On bit body 14, also can get out a fixed hole 100 so that by with manner known in the art drill bit 10 being fixed on the drilling rod as previously mentioned.Similarly, groove 36 also can be formed on the top working surface 16 to hold the embedding blade of being made by hard wear-resistant material such as Talide 12.

According to the present invention, by on bit body or machine or mold the groove 36 of a suitable configuration, the embedding blade 12 that can adopt geometry to have nothing in common with each other, for example complicated or simple roof shape insert design.Then, can embed blade 12 solderings in groove 36, afterwards, but whole bit body of heat treatment and embedding blade.

Cold heading technique allows bit body 14 external configuration to change in wide region, flows with the air that improves wound drill bit 10 tops, can remove dust and similar item better from the probing hole like this.Have and improve one of bit body 14 that air flows and be illustrated in Figure 20 and 21.Reach as previously mentioned shown in Figure 20 and 21, tiltedly compressing surface 32 downwards and extend out to end at and collect mouthfuls 20 curved edge, promoting to improve air and dust, the flowing of landwaste and similar item is so that discharge and take out through axial hole 18.

In typical operation, Fig. 1,2,20,21 and 26-29 shown in drill bit 10 be fixed on the drilling rod, the hole on the drill bit communicates with the drilling rod of hollow like this.Then, drilling rod can be connected in a suitable vacuum pump (not shown), in hole 18, applying a suction force, and take out dust and similar item.Suction force in the hole 18 is passed to dust collection mouth 20 and dust is collected mouth 20 from the compressing surface 32 downward suction of flat side plane 24 tops.Because by around the inside compressive force downwards also that applies with the rock stratum that limits boring, along with dust granules is crossed the compressing surface and the side surface of drill bit 10, the size of dust granules progressively reduces.On effect, This move is with particulate dust and the extruding of drill bit 10 external surfaces, thereby the material that reduces flows freely into opening 20 to discharge by hole 18.

Enforcement of the present invention is not limited by cold-heading preferably, can comprise that temperature is upset or heat is upset yet.For example, in temperature rammer or heat rammer, the material that forms blank can be preheated earlier, in the upsetting operation, causes that material mobile pressure in mould will be significantly less than the pressure in the above-mentioned cold heading technique like this.The typical material preheat temperature of temperature rammer technology is between 1225-1275 degree (Fahrenheit), and hot forging process is between 2200-2350 degree (Fahrenheit).

Patent mentioned in this article here as a reference.

Most preferred embodiment of the present invention is described, but should be appreciated that can embodied in other in the scope of appended claims.

Claims (12)

1, a kind of middle part vacuum drill bit of cold-heading manufacturing of holing on a working surface comprises,

(a) hard, wear-resistant embeds blade; With

(b) metallic object that has a top working surface of irregular surface structure, the top working surface has one in order to hold the groove that described hard, wear-resistant embeds blade, it is characterized in that the metal grain structure of described metallic object is arranged essentially parallel to the profile of described metallic object,

Wherein said metallic object comprises:

An end that passes through described metallic object is to the interior axial hole that extends;

In described metallic object external parallel in the relative recessed flat side surfaces of the shape of falling C of at least two of described metallic object extension of central axis;

At least two relative dust collection mouths, each described collection mouth extends by a corresponding flat side surface and communicates with described axial hole;

Be positioned at each described corresponding a pair of transverse bending shoulder of putting relatively of collecting on mouthful lower limb; With

At the described section of collecting extension between the mouth is a pair of upstanding portion of putting relatively of arc.

2, drill bit as claimed in claim 1 is characterized in that oblique top face that described top working surface comprises that staggered the first couple relatively puts is relative with second pair and puts oblique compressing surface; Described groove described staggered oblique top face and compressing surface between horizontal expansion, to hold described embedding blade.

3, drill bit as claimed in claim 2 is characterized in that the taper of each described oblique top face for projection, and along leaving being directed downwards and stretching out of central axis, and each described oblique compressing surface is the pie shaped recessed face, towards described collections mouthful downwards with stretch out.

4, drill bit as claimed in claim 3, it is characterized in that each described oblique compressing surface with respect to central axis with greater than 20 the degree inclined at inclination angles, and end at the curved edge of collecting mouth with extending out to downwards, helping to improve flowing of air and dust and landwaste, and discharge and take out through described axial hole.

5, drill bit as claimed in claim 4 is characterized in that described collection mouth is circular, and forms the shoulder that has a curved edge.

6, drill bit as claimed in claim 4 is characterized in that described collection is mouthful normally oval-shaped and locatees with about miter angle with respect to central axis, has the shoulder of a curved edge with formation.

7, drill bit as claimed in claim 4 is characterized in that the opposite end of external surface from described top working surface towards described bit body of described bit body is tapered.

8, the method for middle part vacuum drill bit is made in a kind of cold-heading that has a metallic object by a blank manufacturing, and metallic object comprises a top working surface, and blank has a front end and a rear end, and this method may further comprise the steps:

(a) by the described blank of following step cold-heading with the moulding bit body:

Described blank is formed into has a uniform cylinder size;

The front end of described blank is molded as circular cone shape;

Rear end and front end at blank stamp out a centering device;

The opposite flank that has oblique scalloped shaped stress release surface at least two of the side of described blank moulding;

Moulding top working surface is to form staggered oblique top face and oblique compressing surface; With

Axial hole concentric of moulding with centralising device.

(b) process a groove perpendicular to the central axis of bit body, embed blade in order to hold one;

(c) in bit body, process the relative dust collection mouth that communicates with axial hole; With

(d) with in the hard, wear-resistant blade insertion groove.

9, method as claimed in claim 8, it is characterized in that, the rear end that described punch steps is included in blank stamps out one first cannelure, and stamp out one second cannelure of diameter in the described rear end of described blank, and form one recessed at the front end of the described truncated cone greater than described first cannelure.

10, method as claimed in claim 9 is characterized in that, the described groove of processing between each is to staggered tilted conical end face and tilted conical compressing surface is to hold described embedding blade.

11, method as claimed in claim 10 is characterized in that, relative dust collection mouth processing communicates on bit body and with axial hole.

12, method as claimed in claim 11 is characterized in that, described oblique top face is processed to the taper of a projection, and described compressing surface is processed to the recessed concave surface of pie shaped.

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