CN217621003U - Drill bit - Google Patents

Abstract

The utility model provides a drill bit, is including the center drill point and the outside drill point that are located the tool bit front end, the center drill point compare the axial distance of outside drill point distance handle of a knife is far away, just the cutter body diameter of center drill point department is less than the cutter body diameter of outside drill point department, the center drill point includes two at least center drill point cutting edges, the outside drill point include with the corresponding outside drill point cutting edge of center drill point cutting edge week side of tool bit sets up the chip groove of spiral extension. The drill bit adopts the arrangement of the central drill point and the outer drill point, burrs generated during drilling of the carbon fiber composite material can be timely removed while the positioning stability of the drilling is kept, and the defects of tearing, burrs and layering of the carbon fiber composite material are avoided.

Description

Drill bit

Technical Field

The utility model relates to a cutting tool field especially relates to a drill bit for processing carbon-fibre composite.

Background

The carbon fiber composite material is taken as a structural material with excellent performance, has the characteristics of high strength, good heat resistance, good thermal shock resistance, light weight, corrosion resistance, radiation resistance and the like, and is widely applied to the fields of aerospace, automobile manufacturing, marine ships, sports goods and the like at present. However, due to the large anisotropy and low interlayer strength of the material, the carbon fiber composite material is very easy to generate defects such as tearing, burrs and delamination in the processing process. In addition, due to the particularity of the materials, the carbon fiber composite material cannot be processed by using cooling liquid, when a traditional hard alloy cutter is used for dry cutting, the heat dissipation speed of a cutting edge is low, so that local high temperature generated when the carbon fiber composite material is processed by the cutter cannot be dissipated timely, the abrasion of the cutter is accelerated, and the use performance of the carbon fiber composite material is reduced.

Therefore, a drill bit with strong wear resistance, high hardness, fast heat dissipation and better capability of processing the defects of easy tearing, rough edges, delamination and the like of the carbon fiber composite material is urgently needed to solve the defects of the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a drill bit, this drill bit adopt the setting of center drill point and outside drill point, produce the burr when keeping drilling positional stability in time clear away carbon-fibre composite drilling, avoid carbon-fibre composite to take place to tear, deckle edge, the defect of layering.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a drill bit comprises a center drill point and an outer drill point which are positioned at the front end of a tool bit, wherein the center drill point is far away from the axial distance of a tool handle compared with the outer drill point, the diameter of a tool body at the center drill point is smaller than that at the outer drill point, the center drill point comprises at least two center drill point cutting edges, the outer drill point comprises outer drill point cutting edges corresponding to the center drill point cutting edges, and the periphery of the tool bit is provided with a spirally extending chip groove;

correspondingly, the tool bit is a PCD-cemented carbide composite rod which comprises a PCD section and a cemented carbide section, and the central drill point and the outer drill point are positioned in the PCD section; thereby improving the hardness, the wear resistance and the heat conductivity of the cutter head;

correspondingly, the angle W of the central drill point is 120-140 degrees;

correspondingly, the central drill tip comprises two central drill tip cutting edges, each central drill tip cutting edge is provided with a central drill tip first relief angle and a central drill tip second relief angle and respectively forms a central drill tip first relief angle surface and a central drill tip second relief angle surface, a cross edge is formed at the joint of the two central drill tip cutting edges, and chip flutes are arranged on two sides of the cross edge;

correspondingly, the angle of the first back angle of the central drill point is 7-9 degrees, and the angle B of the second back angle of the central drill point is 20-30 degrees;

correspondingly, the angle Q of the outer drill point is 175-180 degrees;

correspondingly, the outer drill tip cutting edge is provided with an outer drill tip first rear angle and an outer drill tip second rear angle, and an outer drill tip first rear angle surface and an outer drill tip second rear angle surface are respectively formed;

correspondingly, the angle of the first back angle of the outer drill point is 7-9 degrees, and the angle of the second back angle of the outer drill point is 20-30 degrees;

correspondingly, a center drill tip cleaning edge is arranged on the periphery of the cutter body where the center drill tip is located, and a center drill tip edge which is located on the same side as the center drill tip cutting edge is arranged on the center drill tip cleaning edge; the edge cleaning of the central drill point provides a required clearance for reducing the drilling resistance of the central drill point, and the edge of the central drill point provides extrusion and support effects for the hole wall when the central drill point is processed;

correspondingly, the length of the edge of the central drill point is 0.5-2.5 mm;

correspondingly, an inner concave structure is arranged on the periphery of the cutter body where the central drill point is located, and the inner concave structure is located at the connecting position of the central drill point and the outer drill point; the problem of poor processing effect caused by poor transition between the central drill point and the outer drill point is solved through the concave structure, and cutting edges on the central drill point and the outer drill point can be effectively distinguished;

correspondingly, the width of the concave structure is 0.02-0.05 mm;

correspondingly, the concave structure is an R angle; the central drill point and the outer drill points are in R-angle transition, so that the problem of stress concentration of the central drill point in the machining process can be reduced;

correspondingly, the radius of the R angle is 0.1-0.8 mm;

correspondingly, a peripheral edge scarfing edge which extends spirally is arranged on the peripheral side of the tool bit, and a peripheral edge which is positioned on the same side as the outer drill point cutting edge and has the same spiral extending direction as the peripheral edge scarfing edge is arranged on the peripheral edge scarfing edge;

correspondingly, the peripheral edge comprises a peripheral edge, a cylindrical edge zone and a supporting edge which are sequentially arranged from near to far away from the outer drill point, the cutting edges of the peripheral edge and the cylindrical edge zone are round edges and are arranged in an inverted cone manner, and the cylindrical edge zone is also provided with a back angle; the edge type form of three composite structures of the peripheral edge, the cylindrical edge band and the supporting edge is adopted, the reaming procedure is completed in the process of drilling the carbon fiber composite board, the time for frequently changing the tool or increasing the loading capacity of the cutter head in the machining process can be greatly saved, the machining efficiency is improved, and the use cost of equipment is reduced;

correspondingly, the peripheral edge and the cylindrical edge band are PCD edges, and the supporting edge is a hard alloy edge;

correspondingly, the back taper range of the peripheral edge and the cylindrical edge is BT 0.08-0.15/100;

correspondingly, the back angle of the cylindrical blade zone is 2-5 degrees; so that the cylindrical blade zone has certain cutting capacity;

correspondingly, the cylindrical blade zone is arranged in an equal width way, and the width of the cylindrical blade zone is 0.02-0.05 mm;

correspondingly, the diameter size of the edge of the cylindrical edge is larger than that of the edge of the peripheral edge, and the difference range is 0.1-0.3 mm;

correspondingly, the blade diameter size of the cylindrical blade zone is larger than that of the supporting blade, and the difference range is 0.005-0.008mm.

The utility model also provides a production process of the drill bit, which is used for slotting the bar and processing the drill bit;

correspondingly, the tool bit and the tool handle are subjected to V-shaped welding.

The beneficial effects of the utility model are that:

1) The front end of the cutter head is provided with a central drill point and an outer drill point, and the outer drill point can cut off all fibers in time in the drilling process of the drill bit, so that the carbon fiber composite board is prevented from being layered due to the interlayer stress of the board caused by the drilling axial force; in the drilling and cutting process of the drill, the outer drill point can cut off all the fibers in time when the center drill point peels off the fibers, so that the phenomenon that the cutting edge of the center drill point exceeds the strength of matrix resin to cause the cracking of the carbon fiber composite material and the spreading of the carbon fiber composite material along the fiber direction of the surface layer is avoided; in the drilling process of the drill bit, the outer drill point can cut off all the fibers in time, and the phenomenon that the plate hole outlet is split due to the fact that a cross blade is too late to cut off the carbon fibers when the cutter is drilled out is avoided;

2) The central drill point is arranged in a protruding way compared with the outer drill point (namely the axial distance between the central drill point and the outer drill point is far away from the tool handle), so that the centering stability of the drill bit can be ensured, and the transverse displacement in the drilling process can be avoided;

3) The R-angle concave structure is arranged at the joint of the central drill point and the outer drill point for clearance transition, so that the problem of poor machining effect caused by poor transition between the central drill point and the outer drill point is solved, the cutting edges on the central drill point and the outer drill point are effectively distinguished, the stress concentration of the central drill point during the machining of the cutter head can be reduced, the possibility of cracks on the central drill point is reduced, and the service life of the central drill point is prolonged;

4) The tool bit is made of the PCD-hard alloy composite rod, the central drill point and the outer drill point are located in the PCD section, compared with the tool bit made of hard alloy, the hardness, the wear resistance and the heat conductivity of the tool bit can be improved, local high-temperature heat generated when the carbon fiber composite material is machined by the tool is dissipated in time, the abrasion speed of the tool is reduced, the performance of the carbon fiber composite material is prevented from being influenced by high temperature, the service life of the tool is prolonged, and compared with the condition that the whole tool bit is made of the PCD material, the cost can be reduced;

5) The week sword is including week sword edge, the cylinder sword area and the sword type form that supports three kinds of integrated configuration of sword, it is specific, week sword edge and cylinder sword area are the circle sword and carry out the back taper setting, the circle sword in cylinder sword area is provided with the relief angle, week sword edge and cylinder sword area are the PCD sword, it is the carbide sword to support the sword, can once process completion drilling and reaming twice process at the in-process of carrying out drilling to carbon-fibre composite panel, can greatly save the time of frequent tool changing or increase the blade disc load among the high-speed course of working, the machining efficiency is improved, the use cost of equipment is reduced.

Drawings

Fig. 1 is a schematic view of an overall structure of a drill according to an embodiment of the present invention;

fig. 2-4 are schematic structural views of a cutter head according to an embodiment of the present invention at different viewing angles;

FIG. 5 is a schematic view of a center drill point angle W according to an embodiment of the present invention;

FIG. 6 is a schematic view of an outside point angle Q according to an embodiment of the present invention;

in the figure:

1. a cutter head; 2. a knife handle;

3. a central drill point; 31. a center drill tip cutting edge; 32. a center drill point first back corner face; 33. a center drill point second back corner face; 34. a chisel edge; 35. a chip pocket; 36. clearing the edge of the center drill point; 37. a central drill tip edge; 38. an R angle;

4. an outer drill point; 41. an outside drill tip cutting edge; 42. an outside drill point first back corner face; 43. a second rear corner surface of the outer drill point;

5. edge cleaning is carried out on the peripheral edge;

6. a peripheral edge; 61. a peripheral edge; 62. a cylindrical margin; 63. a support blade;

7. a chip groove.

Detailed Description

In the description of the present invention, it should be understood that the terms indicating the orientation or the positional relationship are based on the orientation or the positional relationship shown in the drawings, and are only for convenience of description and simplification of the description, but not for indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

The principles and features of the present invention will be described with reference to the drawings, which are provided for illustration only and are not intended to limit the scope of the invention. It should be noted that the drawings are in simplified form and are not to precise scale, and are provided for convenience and clarity in order to facilitate the description of the embodiments of the present invention.

As shown in fig. 1, in an embodiment of the present invention, a drill bit includes a tool bit 1 and a tool shank 2, in this embodiment, the tool bit 1 is a PCD-cemented carbide composite rod, the PCD-cemented carbide composite rod includes a PCD section and a cemented carbide section, and the tool shank 2 is a cemented carbide rod with the same diameter. In this embodiment, the PCD is monolithic artificial polycrystalline diamond, and the cemented carbide is GU20 alloy. Welding a hard alloy end in the PCD-hard alloy composite rod with the hard alloy rod through a silver brazing process;

as shown in fig. 2-4, the tool bit 1 includes a center drill point 3 and an outer drill point 4 at the front end of the tool bit 1, the center drill point 3 is located at a greater axial distance from the shank 2 than the outer drill point 4 (i.e., the center drill point 3 is integrally protruded), and the diameter of the tool body at the center drill point 3 is smaller than the diameter of the tool body at the outer drill point 4, for example, the diameter of the tool body at the center drill point is 0.4 to 0.5 times the diameter of the tool body at the outer drill point. The center drill tip 3 includes at least two center drill tip cutting edges 31, i.e. two or more center drill tip cutting edges 31 may be provided, and the two center drill tip cutting edges 31 and the three center drill tip cutting edges 31 are respectively used for comparison. As is known in the art, three center point cutting edges 31 differ from two center point cutting edges 31 by: when the machining is carried out, hole sites need to be reserved on the workpieces to be machined by the three center drill point cutting edges 31 so as to facilitate drilling machining, and due to the existence of the chisel edges 34, the two center drill point cutting edges 31 can carry out drilling without reserving hole sites on the workpieces to be machined, so that the machining is more convenient. Therefore, in the present embodiment, only two center drill tip cutting edges 31 are provided. The center drill point 3 comprises two center drill point cutting edges 31, each center drill point cutting edge 31 is provided with a first center drill point relief angle and a second center drill point relief angle, and a first center drill point relief angle surface 32 and a second center drill point relief angle surface 33 are respectively formed, a chisel edge 34 is formed at the joint of the two center drill point cutting edges 31, and chip pockets 35 are arranged on two sides of the chisel edge 34, wherein the first center drill point relief angle is 7-9 degrees, the second center drill point relief angle is 20-30 degrees, and the center drill point 3 is 120-140 degrees (W is the included angle of the two center drill point cutting edges 31, as shown in fig. 5);

the center drill point 3 further comprises a center drill point clear edge 36, a center drill point edge 37 and a concave structure, wherein the center drill point clear edge 36 is arranged on the periphery of the cutter body where the center drill point 3 is located, and the center drill point edge 37 which is located on the same side as the center drill point cutting edge 31 is arranged on the center drill point clear edge 36. It should be noted that the central drill clearance 36 and the central drill edge 37 are in the form of clearance and edge, and the "central drill" is only prefixed to distinguish the position of the peripheral edge clearance 51 and the peripheral edge 52, and the peripheral edge clearance 51 and the peripheral edge 52 are the same. An inner concave structure is arranged on the periphery of the cutter body where the central drill tip 3 is located, and the inner concave structure is located at the connection position of the central drill tip 3 and the outer drill tip 4, in this embodiment, the inner concave structure is an R angle 38, the width of the R angle 38 is 0.02 mm to 0.05mm, and the radius of the R angle 38 is 0.1 mm to 0.8 mm. Therefore, the problem of poor processing effect caused by poor transition between the central drill point 3 and the outer drill point 4 can be solved, and the problem of stress concentration of the central drill point 3 in the processing process can be reduced;

the outer drill tip 4 comprises outer drill tip cutting edges 41 corresponding to the number and position of the center drill tip cutting edges 31, in this embodiment, two outer drill tip cutting edges 41 are provided, and thus, two outer drill tips 4 and one center drill tip 3 form a three-point structure. Each outer drill point cutting edge 41 is correspondingly provided with an outer drill point first relief angle and an outer drill point second relief angle, and respectively forms an outer drill point first relief surface 42 and an outer drill point second relief surface 43, and the positions of the outer drill point first relief surface 42 and the outer drill point second relief surface 43 respectively correspond to the positions of the center drill point first relief surface 32 and the center drill point second relief surface 33. Wherein, the angle of the first back angle of the outer drill point is 7-9 degrees, the angle of the second back angle of the outer drill point is 20-30 degrees, and the angle Q of the outer drill point 4 is 175-180 degrees (Q is the included angle of the two outer drill point cutting edges 41, as shown in fig. 6);

the peripheral edge scarfing mechanism is characterized in that a spirally extending peripheral edge scarfing edge 5 is arranged on the periphery of a cutter head, a peripheral edge 6 which is located on the same side with an outer drill point cutting edge 41 and has the same spiral extending direction with the peripheral edge scarfing edge 5 is arranged on the peripheral edge scarfing edge 5, the peripheral edge 6 comprises a peripheral edge 61, a cylindrical edge zone 62 and a supporting edge 63 which are sequentially arranged from near to far away from an outer drill point 4, the cutting edges of the peripheral edge 61 and the cylindrical edge zone 62 are round edges and are arranged in an inverted cone mode, the cylindrical edge zone 62 is further provided with a relief angle, and the blade diameter size of the cylindrical edge zone 62 is respectively larger than the blade diameter size of the peripheral edge 61 and the blade diameter size of the supporting edge 63. The back taper range of the peripheral edge 61 and the cylindrical edge 62 is BT 0.08-0.15/100, the back angle of the cylindrical edge 62 is 2-5 degrees, the cylindrical edge 62 is arranged in an equal width mode, the width of the cylindrical edge 62 is 0.02-0.05 mm, the size difference between the edge diameter size of the cylindrical edge 62 and the edge diameter size of the peripheral edge 61 is 0.2 mm, and the size difference between the edge diameter size of the cylindrical edge 62 and the edge diameter size of the supporting edge 63 is 0.005 mm;

as is known from the foregoing, the tool bit 1 is made of a PCD-cemented carbide composite rod, and therefore, in the present embodiment, the central drill point 3, the outer drill point 4, the peripheral edge 61 and the cylindrical land 62 are all disposed on a PCD segment, that is, a PCD edge, and the support edge 63 is disposed on a cemented carbide segment, that is, a cemented carbide edge, thereby forming edge-shaped forms different in structure and material;

a flute 7 spirally extending from the outer drill tip 3 to the direction of the shank 2 is formed on the periphery of the cutting head 1.

According to the utility model discloses an embodiment drill bit, its processing technology as follows:

1) Selecting a PCD-hard alloy composite bar (PCD and hard alloy are compounded together through a composite sheet, one end is a PCD section, and the other end is a hard alloy section) as a tool bit 1, and selecting a hard alloy bar with the same diameter as a tool handle 2;

2) V-shaped cutting is carried out on the hard alloy end of the PCD-hard alloy composite rod and the hard alloy bar by using slow wire cutting equipment to form V-shaped end parts which are matched with each other;

3) Welding the V-shaped end parts of the PCD-hard alloy composite bar and the hard alloy bar by adopting a silver brazing process to form a drill bit;

4) Bonding a small hard alloy block on the end face of a PCD section of the PCD-hard alloy composite rod, performing discharge punching on the hard alloy block and the end part of the hard alloy rod by using an electric spark pore discharge machine, performing cone angle grinding on a small hole punched by discharge by using hole grinding equipment at 60 degrees to form a tip hole on the hard alloy block and the hard alloy rod, and putting a drill bit on an external grinder for processing by means of the tip hole;

7) The outer diameter, the section difference and the back taper of the drill bit are machined by using an outer circular grinder, the outer diameter runout of the PCD-hard alloy composite rod is required to be less than or equal to 0.003mm, the roughness is required to be less than or equal to Ra0.3, the outer diameter runout of the hard alloy rod is required to be less than or equal to 0.005 mu m, and the roughness is required to be less than or equal to Ra0.4;

8) Taking down the small hard alloy block, and using a tool grinder to perform chamfer grinding on the tool shank;

9) Grooving the PCD-hard alloy composite bar by using a CNC grinding machine, and machining a central drill point 3, an outer drill point 4 and a peripheral edge 6, wherein the PCD section is subjected to discharge machining by using a copper wheel, the hard alloy section is ground by using a diamond grinding wheel, the grooving angle A is within the range of 10-40 degrees, the grooving front angle B is within the range of 8-15 degrees, and the thickness of a tool bit core is d = k x d2 (d is the thickness of the core; k is a constant, generally from 0.25 to 0.35; d2 is the size of the cutting edge diameter actually cut by the drill bit);

10 In order to ensure the smoothness of chip removal, the grinding wheel is used for polishing the slotting rake face, the first rear corner face 32 of the central drill point and the chip groove 35, the polishing depth of the slotting rake face is 0.002-0.005 mm, and the polishing depth of the first rear corner face 32 of the central drill point and the chip groove 35 is 0.002-0.005 mm.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims (11)

1. The utility model provides a drill bit, its characterized in that, is including the center drill point and the outside drill point that are located the tool bit front end, the center drill point compare the outside drill point is far away from the axial distance of handle of a knife, just the cutter body diameter of center drill point department is less than the cutter body diameter of outside drill point department, the center drill point includes two at least center drill point cutting edges, the outside drill point include with the corresponding outside drill point cutting edge of center drill point cutting edge the week side of tool bit sets up the chip groove of spiral extension.

2. The drill bit of claim 1, wherein the cutter head is a PCD-cemented carbide composite rod comprising a PCD segment and a cemented carbide segment, the central drill point and the outer drill points being located in the PCD segment.

3. The drill bit of claim 1, wherein the angle W of the center drill tip is between 120 ° and 140 °.

4. The drill bit of claim 1, wherein the angle Q of the outer point is 175 ° to 180 °.

5. The drill bit of claim 1, wherein a center tip clearance edge is provided around the body on which the center tip is located, and a center tip edge is provided on the same side of the center tip clearance edge as the center tip cutting edge.

6. The drill bit of claim 1, wherein a concave structure is disposed around the periphery of the body where the center drill point is located, and the concave structure is located at a junction of the center drill point and the outer drill point.

7. The bit according to claim 6, wherein the concave structure is an R-angle.

8. The drill according to claim 1, wherein a peripheral edge clearance side extending spirally is provided on a peripheral side of the tip, and a peripheral edge on the same side as the outer tip cutting edge and extending spirally in the same direction as the peripheral edge clearance side is provided on the peripheral edge clearance side.

9. The drill bit as claimed in claim 8, wherein the peripheral edge comprises a peripheral edge, a cylindrical land and a supporting edge which are arranged from near to far from the outer drill point, the cutting edges of the peripheral edge and the cylindrical land are round edges and are arranged in an inverted cone, and the cylindrical land is further provided with a relief angle.

10. The drill bit of claim 9, wherein the peripheral edge and the cylindrical land are PCD edges and the support edge is a cemented carbide edge.

11. The drill bit of claim 9, wherein the cylindrical land has a diameter dimension that is greater than a diameter dimension of the peripheral edge and a diameter dimension of the support edge, respectively.

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