CN107900420A - A kind of drill bit suitable for fibre reinforced composites drilling processing - Google Patents

Abstract

The invention discloses a kind of drill bit suitable for fibre reinforced composites drilling processing, including cutting edge, chip space, main cutting face, drill main body, secondary cutting face, head, drill bit point of a knife, helicla flute, guide frame, sharp angle, the first chamfering, the second chamfering, chisel edge, main chisel edge angle, secondary chisel edge angle, main gap, secondary gap and axial rake.The beneficial effects of the invention are as follows：The drill bit that the present invention is processed using carbon fibre reinforced composite (CFRP), glass fibre reinforced composion (GFRP) and aramid fiber enhancing composite material (AFRP) drilling, the drill bit has helical angle alterable features and specifically switches in and out angle, with reference to angle and optimizing after the first relief angle and second, drilling torque can be minimized.In addition, big chisel edge anterior angle can obtain good cutting ability and drilling outgoing quality in machining fiber reinforced composite material and its laminated material.

Description

A kind of drill bit suitable for fibre reinforced composites drilling processing

Technical field

The present invention relates to a kind of drill bit, is specially a kind of drill bit suitable for fibre reinforced composites drilling processing, belongs to Drilling applied technical field is assembled in fibre reinforced composites.

Background technology

Fibre reinforced composites, as CFRP, GFRP and AFRP are widely used in aerospace field, in fiber reinforcement Need to carry out substantial amounts of drilling operation in composite material assembling process, and it is more demanding for drilling quality, processed for drilling It is a kind of challenge.

Easily there is hole wall ablation, scuffing, layering, bore entrance and outlet during drilling in fibre reinforced composites Easily there is the defects of splitting, burr, directly affect the military service performance of part.The obvious anisotropy of fibre reinforced composite material, Also so that its drilling cutter and traditional metal working tool are significantly different, it is desirable to which cutter can have good cutting sharpness With special geometry, fibre cutting is realized.Moreover, fibre reinforced composites generally all have good wearability, it is right Tool wear is serious, therefore, proposes a kind of drill bit suitable for fibre reinforced composites drilling processing regarding to the issue above.

The content of the invention

The purpose of the present invention is that to solve the above-mentioned problems and provides one kind and be suitable for fibre reinforced composites system The drill bit of hole machined, drill bit have the variable helical for determining starting helical angle and final helical angle, and the first definite relief angle With the second relief angle, minimize drilling torque.Drill bit can obtain good drilling quality in drilling fibre reinforced composites.

The present invention is achieved through the following technical solutions above-mentioned purpose, and one kind adds suitable for fibre reinforced composites drilling The drill bit of work, including drill main body and it is connected as overall head with the drill main body, the drill main body and the head The first chamfering and the second chamfering are equipped between portion；The drill main body is equipped with helicla flute, and the institute of the side of the helicla flute State drill main body and be equipped with chip space；The head is equipped with guiding mechanism, and the end on the head is equipped with drill bit point of a knife；Institute State and chisel edge is equipped with the center of drill bit point of a knife, and plane forms main cutting face where the chisel edge；Where the main cutting face Edge is equipped with cutting edge, and secondary cutting face is formed on the head being connected with the main cutting face；The relief angle in the main cutting face For 10 ° to 20 °, the relief angle in the pair cutting face is 10 ° to 40 °, at least one described cutting edge prolongs from the drill bit point of a knife Drill main body is extended, the helical angle of each blade is 25 ° to 45 ° at point of a knife, extends to handle of a knife as 0 ° to 30 °.

Wherein, the wherein relief angle in main cutting face is 10 ° to 30 °, preferably 10 ° to 20 °, the relief angle in secondary cutting face for 10 ° extremely 40 °, preferably 20 ° to 35 °；At least one cutting edge extends to drill main body from drill bit point of a knife, its helical angle is variable helical, institute The starting helical angle for stating cutting edge is 45 ° to 55 °, final 5 ° to 30 ° of helical angle, preferably 10 ° to 20 °.

Preferably, helical angle is continuously reduced to final helical angle, spiral cutting sword from starting helical angle does not have helical angle not Any straight line portion become.Change rate along the helical angle of helix distance change is continuous.Therefore, spiral cutting sword does not have It is that spiral angular rate of change is constant to have any part.Spiral angle function is preferably nonlinear function, such as exponential function.Helical angle Function is particularly preferably the spline function reduced with starting helical angle to final helical angle.Suitable spline function is any non- Linear spline function, such as index, secondary or cubic spline function.

In fibre reinforced composites during drilling, the design of variable helical angle and main cutting face and pair as described above Cutting face combination can significantly reduce moment of torsion.Relatively large starting helical angle contributes to quickly and neatly cutting fibre strengthens Composite material.In addition, big starting helical angle also provides low cutting resistance.Main cutting face and secondary cutting face combination can improve hole Processing quality, the particularly quality of portalling when drilling fibre reinforced composites as described herein.The reality that the present inventor carries out Test it has been shown that the fibre reinforced composites outlet splitting after processing is less.

In instances, particularly it is applicable in the example of automatic drilling, primary clearance should be 11 ° to 19 °, and preferably 13 ° extremely 17 °, most preferably about 15 °.

In instances, particularly it is applicable in the example of automatic drilling, front clearance is 15 ° to 25 °, is preferably 17 ° to 23 °, Most preferably about 20 °.

Drill bit only has two cutting edges.However, it is also possible to have more than two cutting edges, such as three or four cuttings Sword.In embodiments, preferably two or three cutting edges.

Drill bit has guide frame, and drill bit guide frame has centering tip, and centring point further increases bit performance, Suitable assistance is accurately positioned.Especially, extending guide frame length helps to form the hole of high quality.

The inventors discovered that the guide frame with least 2mm length is particularly effective.Guide frame length is preferably extremely Few 2.5mm~5mm.The 40% to 60% of a diameter of bit diameter of guide frame, is preferably 44% to 50%, most preferably about 47%.

In general, bit diameter is measured by drill margin turning point, i.e., the diameter measured in the widest part of drill bit.Work as drill bit During including guide frame, bit diameter is also measured in the widest portion of drill main body, usually the front end in drill main body.Boring There are during transition portion between head main body and guide frame, bit diameter is diameter of the drill main body adjacent to transition portion.

Another benefit for increasing guide frame on drill bit is exactly can reconditioning again.Specifically, comprising guiding The drill bit of structure, in instances, can at least re-grind twice.

In the case of there are guide frame, it is possible to achieve the further improvement of performance.The inventors discovered that it is provided with double The drill bit of chamfering can reduce the moment of torsion in process, improve the cutting transition between tip and drill main body.

Drill bit has transition portion, the portion that transition portion extends after guide frame between guide frame and drill body Dividing has the first chamfering, there is the second chamfering in the part that the first chamfering extends below.

Transition portion length preferably at least 5mm, most preferably at least 8mm.The length of transition portion is axial length direction.

First chamfered part appropriate length at least 3mm, preferably at least 4mm.The length of chamfered section is axial length.

Second chamfered part appropriate length at least 2mm, preferably at least 3mm.The length of chamfered section is axial length.

The length of suitable first chamfered part should be greater than the length of the second chamfered part.First chamfered part falls than second Angle part length at least 10%, preferably long about 20%.

Second chamfered part angle is 5 ° to 15 °, is preferably 8 ° to 12 °, most preferably about 10 °.Chamfer angle is by falling Angle plane and the angle formed parallel to the plane of drill axis.

First chamfered part proper angle is 10 ° to 20 °, is preferably 12 ° to 18 °, most preferably about 15 °.

First chamfered part angle should be greater than the second chamfered part angle.First chamfered part angle should be than the second chamfered section Subangle greatly at least 20% is preferably at least big by 30%.

Drill bit point of a knife includes chisel edge, and relatively small chisel edge length as described herein helps to reduce moment of torsion.Chisel edge angle Degree is preferably 100 ° to 125 °, more preferably 105 ° to 120 °.

In instances, particularly it is applicable in the example of automatic drilling, chisel edge angle is 110 ° to 120 °, and preferably 114 ° extremely 118 °, most preferably about 116 °.

Chisel edge length is preferably 0.03mm to 0.15mm, more preferably 0.06mm to 0.14mm, most preferably from about 0.1mm.

In the case where drill bit only has two cutting edges, above-mentioned chisel edge length is especially suitable.There are 3 cutting edges in drill bit In the case of, preferable chisel edge length is 0.03mm to 0.07mm, is preferably 0.03mm to 0.05mm.

Sharp angle is parallel to drill axis and parallel to the flat of two cutting edges between cutting edge and minor cutting edge Angle on face.

Drill bit sharp angle is at least 80 °, preferably at least 85 °, most preferably at least 89 °.

Drill bit sharp angle should be no more than 140 °, preferably more than 120 °.These values (upper and lower bound) of sharp angle can with appoint What combination is present in example.

In embodiments, in the case of being especially suitable for automatic drilling, sharp angle is 80 ° to 90 °, most preferably from about 85 °.

Sharp angle as described herein helps to reduce moment of torsion and processes good exit hole quality.

Axial rake should be no more than 20 °, preferably more than 15 °, be most preferably not more than 11 °.

Drill bit includes the right hand or left hand helix.Right-handed helix is preferred.

Bit diameter is 1mm to 50mm, preferably 1 to 20mm, most preferably 2mm to 15mm.

Suitably, should be less than for the drill bit of a diameter of 6.5mm or bigger (such as 6.5mm to 15mm), starting helical angle 40 °, preferably in the range of 28 ° to 32 °, final helical angle is preferably 8 ° to 12 ° in the range of 0 ° to 20 °.Helical angle from Originate and be finally reduced at least 10 °, preferably at least 15 °.

Being less than 6.5mm for diameter, (such as 2mm is extremely<Drill bit 6.5mm), starting helical angle are at least 40 °, preferably exist In the range of 48 ° to 52 °, and helical angle is terminated in the range of 0 ° to 35 °, preferably 8 ° to 12 °.Helical angle is from starting to most 20 °, preferably at least 30 ° are reduced at least eventually.

The fibre reinforced composites are that carbon fibre reinforced plastic (CFRP), glass reinforced plastic (GFRP) or aramid fiber are fine Tie up composite material (AFRP)；The drill process includes manual drilling or digital control hole；The method is laminated material drilling.

Drill bit material is made of carbide.Preferred carbide is tungsten carbide (WC).Particularly preferred cobalt concentration is total hard The 3wt% of matter weight alloy to 10wt%, more preferably 5wt% to 7w%, most preferably about 6wt%.

Drill bit has coating, can be partially or fully coated.Preferred coatings are wear-resistant coatings, are had lower than the cutter of non-coating Friction coefficient.

Suitable coating includes the coating (such as TiN, AlTiN etc.) based on metal nitride, based on metal oxide Coating (such as AlxOy, AlxCryO etc.), carbon-base coating (such as DLC, diamond coatings etc.).Diamond coatings are preferred.

The beneficial effects of the invention are as follows：

1st, drill bit has a variable helical for determining starting helical angle and final helical angle, and the first definite relief angle and the Two relief angles, minimize drilling torque；

2nd, drill bit has main chisel edge and the second chisel edge, and definite drill bit nose angle and chisel edge anterior angle, can be in drilling Fibre reinforced composites obtain good drilling quality；

3rd, the torsion problem when processing the composite material containing fiber can be solved by a series of tool characteristics, I.e. specific starting and the variable helical of termination point, and the specific relief angle in primary and secondary face.

Brief description of the drawings

Fig. 1 is the side view of the variable helical drill bit of the example one of the present invention；

Fig. 2 is the end face axial view of Fig. 1 drill bits；

Fig. 3 is the enlarged view of Fig. 1 drill bits；

Fig. 4 is the result figure of the exit hole quality test of drilling CFRP materials in present example；

Fig. 5 is the result figure of the exit hole quality test of other drill bit drilling CFRP materials in present example.

In figure：1st, cutting edge, 2, chip space, 3, main cutting face, 4, drill main body, 5, secondary cutting face, 6, head, 7, drill bit Point of a knife, 8, helicla flute, 10, guide frame, 12, sharp angle, the 14, first chamfering, the 16, second chamfering, 20, chisel edge, 22, main chisel edge Angle, 24, secondary chisel edge angle, 30, main gap, 32, secondary gap.34th, axial rake.

Embodiment

Below in conjunction with the attached drawing in the embodiment of the present invention, the technical solution in the embodiment of the present invention is carried out clear, complete Site preparation describes, it is clear that described embodiment is only part of the embodiment of the present invention, instead of all the embodiments.It is based on Embodiment in the present invention, those of ordinary skill in the art are obtained every other without making creative work Embodiment, belongs to the scope of protection of the invention.

Please refer to Fig.1 shown in -5, a kind of drill bit suitable for fibre reinforced composites drilling processing, including drill main body 4 and it is connected as overall head 6, falling equipped with first between the drill main body 4 and the head 6 with the drill main body 4 14 and second chamfering 16 of angle；The drill main body 4 is equipped with helicla flute 8, and the drill main body of the side of the helicla flute 8 4 are equipped with chip space 2；The head 6 is equipped with guiding mechanism 10, and the end on the head 6 is equipped with drill bit point of a knife 7；It is described Chisel edge 20 is equipped with the center of drill bit point of a knife 7, and 20 place plane of the chisel edge forms main cutting face 3；The institute of main cutting face 3 Edge be equipped with cutting edge 1, secondary cutting face 5 is formed on the head 6 being connected with the main cutting face 3；The main cutting The relief angle in face 3 is 10 ° to 20 °, and the relief angle in the pair cutting face 5 is 10 ° to 40 °, at least one described cutting edge 1 is from described Drill bit point of a knife 7 extends to drill main body 4, and the helical angle of each blade is 25 ° to 45 ° at point of a knife, extends to handle of a knife and is arrived for 0 ° 30°。

The helical angle is reduced at least 15 ° from initial angle to termination point, and originates helical angle smoothly continuously mistake Cross to termination helical angle, and it is 45 ° to 55 ° to originate helical angle, it is 8 ° to 15 ° to terminate helical angle.

The starting helical angle is 25 ° to 35 °, and it is 8 ° to 15 ° to terminate helical angle.

The relief angle in the main cutting face 3 is 10 ° to 20 °, and the relief angle in secondary cutting face 5 is 15 ° -30 °.

The drill bit only has two cutting edges 1, and each cutting edge 1 includes a back edge angle；Set on the cutting edge 1 It is equipped with main gap 30 and time gap 32.

The drill bit point of a knife 7 has chamfering, chamfer dimesion 1.5-2.5mm, and sharp angle 12 is 85 ° to 110 °, axial rake 34 For 8 ° to 15 °.

There is transition portion between chamfering and drill main body, the chamfered transition portion for having Part I behind chamfered part Point, and the second transition chamfered part after First Transition chamfered part and the optionally after the second transition chamfered part Three transition chamfered parts.

The chisel edge 20 is 0.05 to 0.15mm, and it is 100 ° to 125 ° that the chisel edge 20, which forms main chisel edge angle 22, secondary chisel edge Angle 24 is 145 ° to 155 °.

A kind of drill bit suitable for fibre reinforced composites drilling processing, the fibre reinforced composites are carbon fibers Reinforced plastics (CFRP), glass reinforced plastic (GFRP) or aramid fiber reinforced composite (AFRP)；The drill process includes hand Dynamic drilling or digital control hole；The method is laminated material drilling.

The step of the described method includes with drill bit drilling fibre reinforced composites.

The drill bit of Fig. 1 displaying present invention.Drill bit includes handle (not showing), drill main body 4 and head 6.Two helicla flutes 8 from Drill bit point of a knife 7 extends to drill main body 4.It is relatively large in the helical angle of spiral section start, it is 50 °, in spiral end and phase It it is 10 ° to smaller.For start angle, other angles are also possible, such as 25 ° to 60 °, it is suitably 40 ° to 60 °, it is right In termination point be 0 ° to 35 °.

Formed using spline function spiral.Selection spline function causes helical angle from section start with the change of axial distance It is smoothly and continuously.Compared with the variable helical of traditional helical angle stepped change bores, conventional variable auger causes for this It is step transition between helical angle.In contrast, which has smooth and continuous helical angle change, is no longer that ladder becomes Change.This has the advantages that notable, i.e., more effectively can remove and discharge material along chip space.

The width of chip space 2 and be substantially constant along the length of chip space 2.

Drill bit further includes extension guide frame 10.It is 90 ° that cutting edge 1 at 10 tip of guide frame, which forms sharp angle 12,.Its His angle be also it is possible, such as 80 ° to 140 °.

Drill bit is included in the gradual transition portion between relatively narrow guide frame 10 and wider drill main body 4.It is double Chamfering is used to reduce moment of torsion and increases cutting resistance, to be sent out during offsetting the transition point cutting between chamfering and drill main body 4 Raw impetus.Specifically, it is the first chamfered part 14 that 15 ° of length are 5mm that drill bit, which includes angle, and angle is 10 ° Length is the second chamfering 16 of 4mm, other chamferings and length can be as described above.Indeed, it is possible to there is extra chamfering (i.e. Three, the chamfering such as 4th).

The 47% of a diameter of bit diameter of guide frame 10.As will be explained herein, measured at the widest point of drill bit Bit diameter, in this case, bit diameter are identical near the farthest size of the second chamfering 16 with drill main body 4.

Extend 10 long 3mm of guide frame, measured from the point of the forefront close to the first chamfering 14 to close to point.Other Length of lead is also possible, such as 2mm to 6mm.

Extended 10 structure of guide frame can recycle, so as to allow identical drill bit to be used for multiple times.

Fig. 2 illustrates the axial view of drill bit.Chisel edge 20 has the length and 110 ° of chisel edge angle 22 of 0.1mm.Such as this Literary other described 20 length of chisel edge and 20 angle of chisel edge are possible.

Fig. 3 illustrates head 6, particularly the enlarged view of guide frame 10.The cutting edge 1 and minor cutting edge of the point are set There are main gap 30 (also referred to as interarea or side clearance) and secondary gap 32 (also referred to as time face or side clearance).It is respective Angle (also referred to as gap) is respectively 10 ° and 20 °.In another example with other same geometry, corresponding chamfering For 25 ° and 20 °.Other main gap angles and time clearance angle are also possible, for example, respectively 5 ° to 40 ° (preferably 10 ° to 40 °) and 10 ° to 40 °.

Drill bit has 8 ° of axial rake 34.In another example with other same geometry, axial rake 34 For 10 °.Other anterior angles are probably such as 3 ° to 15 °.

The bit performance of the present invention is compared with other bit performances.Quantify to bore by measuring axial force and hole quality Head performance.

Test piece in experiment is the CFRP materials of 10mm thickness.Test result is as shown in table 1.

Test tool	Drill bit of the present invention	Other test drill bits
			Axial force	64N	97N
Outgoing quality (such as Fig. 4)	Well (Fig. 4)	Cleave (Fig. 5)

Drill bit of the present invention has good outgoing quality, and less drilling axial force, is very suitable for processing fiber reinforcement and answers Condensation material.

It is obvious to a person skilled in the art that the invention is not restricted to the details of above-mentioned one exemplary embodiment, Er Qie In the case of without departing substantially from spirit or essential attributes of the invention, the present invention can be realized in other specific forms.Therefore, no matter From the point of view of which point, the present embodiments are to be considered as illustrative and not restrictive, and the scope of the present invention is by appended power Profit requires rather than described above limits, it is intended that all in the implication and scope of the equivalency of claim by falling Change is included in the present invention.Any reference numeral in claim should not be considered as to the involved claim of limitation.

Moreover, it will be appreciated that although the present specification is described in terms of embodiments, not each embodiment is only wrapped Containing an independent technical solution, this narrating mode of specification is only that those skilled in the art should for clarity Using specification as an entirety, the technical solutions in the various embodiments may also be suitably combined, forms those skilled in the art It is appreciated that other embodiment.

Claims (10)

1. a kind of drill bit of drilling processing, including drill main body (4) and it is connected as overall head with the drill main body (4) (6), it is characterised in that：The first chamfering (14) and the second chamfering are equipped between the drill main body (4) and the head (6) (16)；The drill main body (4) is equipped with helicla flute (8), and on the drill main body (4) of the side of the helicla flute (8) Equipped with chip space (2)；The head (6) is equipped with guiding mechanism (10), and the end of the head (6) is equipped with drill bit point of a knife (7)；Chisel edge (20) is equipped with the center of the drill bit point of a knife (7), and plane forms main cutting face where the chisel edge (20) (3)；Edge where the main cutting face (3) is equipped with cutting edge (1), the head (6) being connected with the main cutting face (3) It is upper to form secondary cutting face (5)；The relief angle of the main cutting face (3) is 10 ° to 20 °, and the relief angle of the pair cutting face (5) is 10 ° To 40 °, at least one described cutting edge (1) extends to drill main body (4), the spiral shell of each blade from the drill bit point of a knife (7) Swing angle is 25 ° to 45 ° at point of a knife, extends to handle of a knife as 0 ° to 30 °.

A kind of 2. drill bit of drilling processing according to claim 1, it is characterised in that：The helical angle from initial angle to Termination point is reduced at least 15 °, and originates helical angle and be smoothly continuously transitioned into termination helical angle, and originates helical angle and be 45 ° to 55 °, it is 8 ° to 15 ° to terminate helical angle.

A kind of 3. drill bit of drilling processing according to claim 1, it is characterised in that：The starting helical angle arrives for 25 ° 35 °, it is 8 ° to 15 ° to terminate helical angle.

A kind of 4. drill bit of drilling processing according to claim 1, it is characterised in that：The relief angle of the main cutting face (3) For 10 ° to 20 °, the relief angle of secondary cutting face (5) is 15 ° -30 °.

A kind of 5. drill bit of drilling processing according to claim 1, it is characterised in that：The drill bit only has two cuttings Sword (1), each cutting edge (1) include a back edge angle；Main gap (30) and time gap are provided with the cutting edge (1) (32)。

A kind of 6. drill bit of drilling processing according to claim 1, it is characterised in that：The drill bit point of a knife (7) has chamfering, Chamfer dimesion is 1.5-2.5mm, and sharp angle (12) is 85 ° to 110 °, and axial rake (34) is 8 ° to 15 °.

A kind of 7. drill bit of drilling processing according to claim 6, it is characterised in that：Have between chamfering and drill main body Transition portion, there is the chamfered transition part of Part I, and after First Transition chamfered part behind chamfered part Two transition chamfered parts and optionally the 3rd transition chamfered part after the second transition chamfered part.

A kind of 8. drill bit of drilling processing according to claim 1, it is characterised in that：The chisel edge (20) for 0.05 to 0.15mm, it is 100 ° to 125 ° that the chisel edge (20), which forms main chisel edge angle (22), and secondary chisel edge angle (24) is 145 ° to 155 °.

9. a kind of drill bit for being suitable for fibre reinforced composites drilling processing according to any one of claim 1-8, its feature exist In：The fibre reinforced composites are carbon fibre reinforced plastic, glass reinforced plastic or aramid fiber reinforced composite；The brill Hole step includes manual drilling or digital control hole；The method is laminated material drilling.

10. a kind of drill bit suitable for fibre reinforced composites drilling processing according to claim 9, its feature exist In：The step of the described method includes with drill bit drilling fibre reinforced composites.