CN219130877U - PCD drill bit - Google Patents

Abstract

A PCD drill bit includes an elongated body member having a longitudinal axis, a shank mountable to a rotary machine, a bit tip, and a drill body having first and second flutes disposed thereon. Providing a first PCD wafer on a face of a first junk slot, providing a second PCD wafer on a face of a second junk slot, the second PCD wafer being located on one side of the longitudinal axis; the first PCD wafer is for being machined into a drill tip, the end extending towards the longitudinal axis on a side thereof adjacent the longitudinal axis and beyond the longitudinal axis such that the longitudinal axis is located on the PCD wafer. According to the cutter, the single PCD piece is arranged beyond the longitudinal axis, so that the front end chisel edge of the whole drill bit is made of PCD materials in the width direction, the wear resistance of a drill point without a cutting edge point is improved, and the service life of the cutter can be remarkably prolonged even if one side chisel edge is not made of PCD materials completely.

Description

PCD drill bit

Technical Field

The utility model relates to a hole machining cutter, in particular to a cutter manufactured by welding PCD materials on a cutter body, which improves the service life of a drill bit in hole machining.

Background

The drill is a generic name for a tool that is used to drill through holes or blind holes in solid materials and to ream existing holes. The conventional types are as follows: twist drills, spade drills, deep drills, reamer drills, center drills, etc.

The tool with polycrystalline diamond (PCD) as the material provides a solution for prolonging the service life of the drill bit in nonferrous metal forming hole machining, especially for cutting difficult-to-machine materials.

PCD drill bit is made by welding PCD material on the cutter body. In general, PCD material is produced by sintering diamond particles with a metal-based binder at high temperature and high pressure together with a substrate. PCD tips can be cut by electrical discharge machining or laser and welded to a cemented carbide or steel substrate and then sharpened to form PCD drill bits, which are particularly effective in high speed machining of nonferrous metals such as aluminum, as well as highly abrasive synthetic materials and plastics. PCD bits are widely used in milling nonferrous metals, composites, plastics, and extremely difficult to machine superalloys.

Even so, only tungsten steel is used as a material to manufacture the chisel edge of the front end (the cutting end which is firstly contacted with the material, which is called a drill point) of the PCD drill, and in actual machining, the chisel edge is often damaged before the PCD main blade, so that a cutter needs to be replaced, and the replaced cutter needs to be polished again or is scrapped as a whole. To solve these problems, a whole coated CVD diamond tool is produced, the wear rate of the tool is comparable throughout, and the size and dimensional accuracy are limited by the coating process. The other is that PCD patches are adopted on the steps, and the service life of the integral front-end PCD drill bit including the chisel edge is greatly prolonged, but the cutter is difficult to process and cannot meet the processing requirement of large diameter.

In order to realize the manufacture of the large-diameter PCD drill bit, the three-dimensional sintering PCD is adopted in the prior art, PCD materials are arranged along a small part of a cutting edge (including a chisel edge), and the workability and the large diameter are both considered, but the specification of a cutter finished product is determined by the sintering of the materials, only the cutter finished product can be polished for a small number of times, nonstandard processing is difficult to realize according to the subsequent requirements, and the material cost is also high and is difficult to obtain.

Disclosure of Invention

The utility model aims to provide a PCD drill bit, realize nonstandard processing of a cutter and meet production requirements of actual working conditions.

Another object of the utility model is to provide a PCD drill bit which facilitates coping in cutter applications and meets production requirements of actual working conditions.

It is still another object of the present utility model to provide a PCD drill bit that increases the wear resistance of the point where the drill tip does not have a cutting edge, and increases the useful life of a nonferrous metal forming hole machining tool.

It is a further object of the present utility model to provide a PCD drill bit that facilitates the machining of cutters and enables low cost manufacture of PCD drill bits.

The PCD drill bits provided by the present utility model include an elongate body member having a longitudinal axis, a shank mountable to a rotary machine, a cutting tip (or bit), and a drill body. The drill body is a part located behind the drill tip in the feed direction of the drill, which moves with the feed of the drill tip. Typically, at least two cutting edges are included on the drill tip. At least one junk slot, and more typically at least two junk slots, are provided in the drill body. The junk slot is arranged on the drill body, one end of the junk slot extends towards the shank (or called the tail end of the slot), and the other end extends to the drill tip (or called the front end of the slot).

To facilitate the securing of the PCD material to the tool, a sheet material containing the PCD material (also referred to as PCD wafer) is secured to the junk slots and then machined to form the drill tip. Common PCD wafers typically comprise a laminate of two materials, a substrate layer and a PCD layer, wherein the substrate layer is typically made of a metallic material, such as: tungsten steel, hard alloy and the like, and the PCD layer is positioned on the substrate layer. And bonding, sintering or welding the substrate layer on the chip removal groove.

For PCD bits, common morphologies are as follows: machining a drill body on a bar made of a cylindrical metal material, and further performing the following steps: the chip removing groove is formed on a stepped bar stock formed by connecting a plurality of cylindrical metal materials with various diameters end to end, one chip removing groove can be positioned on a plurality of cylinders with different diameters to form a drill body, and PCD chips are arranged on the cylinders with different diameters, but the drill point usually only has one, namely the part of the cutter firstly contacted with the materials to cut.

Drill tips and bodies are machined from a cylindrical bar of metal material or from a plurality of cylindrical bars of various diameters, and junk slots are formed by grinding or laser machining to remove the metal material. The chip removal groove is usually a straight groove body or a spiral groove body from the front end of the groove to the tail end of the groove.

A PCD drill bit comprising a first junk slot and a second junk slot, a first PCD wafer being disposed on a face of the first junk slot, a second PCD wafer being disposed on a face of the second junk slot, the second PCD wafer being located on one side of a longitudinal axis for machining into a main edge on one side of the drill tip. The first PCD wafer is intended to be machined into the other side major and chisel edges on the drill tip, with one side of the PCD wafer adjacent the longitudinal axis extending toward the longitudinal axis and beyond the longitudinal axis so that the longitudinal axis is located on the PCD wafer.

In another PCD drill bit, the first PCD wafer has a PCD layer thickness exceeding the chisel edge width of the cutter.

In another PCD drill bit, the ratio of the distance from the longitudinal axis of one side of the first PCD sheet to the diameter of a circular surface formed by intersecting a radial plane with the drill body is 5% -20%. The ratio is preferably 5% -15%, such as: 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% and 15%.

In another PCD drill bit, the ratio of the distance of one side of the first PCD wafer furthest from the longitudinal axis beyond the edge of the longitudinal axis to the diameter of a circle intersecting a radial plane with the drill body is 10%.

The above-described PCD solution is equally applicable for forming hole machining PCD drill bits having 3 or more cutting edges, i.e. the cutter is provided with a first PCD wafer on the face of the flute comprising the first chip groove, the first PCD wafer being provided on the face of the first chip groove, one end of the first PCD wafer being intended to be machined into a drill point, the end being extended towards and beyond the longitudinal axis on the side closest to the longitudinal axis such that the longitudinal axis is located on the PCD wafer.

In another specific embodiment of the PCD drill bit, chip grooves are formed in a stepped bar formed by connecting cylindrical metal materials with a plurality of diameters end to end, one chip groove is positioned on a plurality of cylinders with different diameters to form a drill body, and PCD chips are arranged on the cylinders with different diameters and only one drill tip is arranged.

In another specific embodiment of the PCD drill bit, a third junk slot is also provided on the drill body.

In another specific embodiment of the PCD drill bit, a plurality of junk slots are further provided on the drill body such that the total number of junk slots is greater than 3.

The technical scheme of the utility model has the beneficial effects that:

it is generally believed that the chisel edge of a drill for forming a hole requires two blades of PCD material to meet the machining. According to the utility model, by utilizing the characteristic of PCD layer thickness of the PCD piece, a single PCD piece is arranged beyond the longitudinal axis, so that the front end chisel edge of the whole drill bit is made of PCD materials in the width direction, the wear resistance of the drill point without a cutting edge point is improved, and the service life of a cutter can be remarkably prolonged even if one side (auxiliary) cutting edge is not made of PCD materials.

The PCD chip adopted by the PCD drill bit is easier to obtain, the material cost is obviously reduced, nonstandard cutters with different diameters are produced according to the requirements of working conditions, the number of times of grinding the cutters is not limited, and the use cost of the cutters is obviously reduced.

Compared with the three-dimensional sintering PCD technology, the technical scheme of the utility model has the advantages of more convenient processing and lower manufacturing cost. The scheme of the utility model can be adopted for forming holes with 3 or more cutting edges to process PCD drill bits, thereby having universality.

Drawings

FIG. 1 is a schematic view of a PCD drill bit in accordance with one embodiment of the present utility model;

FIG. 2 is a schematic view of the PCD drill bit of FIG. 1 at an angle;

FIG. 3 is an enlarged schematic view of another angle of the PCD drill bit of FIG. 1;

fig. 4 is an enlarged partial schematic view of the drill bit of fig. 3.

Detailed Description

The technical scheme of the present utility model is described in detail below with reference to the accompanying drawings. The embodiments of the present utility model are only for illustrating the technical scheme of the present utility model and not for limiting the same, and although the present utility model has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the technical scheme of the present utility model, which is intended to be covered by the scope of the claims of the present utility model.

Fig. 1 is a schematic view of the PCD drill according to an embodiment of the present utility model, fig. 2 is a schematic view of the PCD drill shown in fig. 1 at one angle, fig. 3 is an enlarged schematic view of the PCD drill shown in fig. 1 at another angle, and fig. 4 is a partially enlarged schematic view of the PCD drill shown in fig. 3. As shown in fig. 1, 2, 3 and 4, the PCD drill bit of the present embodiment comprises an elongate body member having a longitudinal axis 400, a shank 300 mountable to a rotary machine, a drill point 100 (or bit), and a drill body 200. In hole machining, the drill tip 100 is the location that first contacts and cuts material and typically includes at least two cutting edges. As the drill tip 100 cuts material, channels are gradually formed from the outside to the inside and gradually deepen in the object, where the direction in which the channels continue to deepen, also referred to as the feed direction of the drill. The drill body 200 is a component located behind the drill tip 100 in the feed direction of the drill, and moves with the feed of the drill tip 100 to discharge generated chips.

The drill body 200 of this embodiment is formed by connecting a plurality of cylindrical bars with different diameters end to end, in fig. 1, the drill body 200 includes a first cylindrical bar 210 and a second cylindrical bar 220, a chip groove 230 is formed on the drill body 200 by removing metal material by grinding or laser processing, one end of the chip groove 230 extends toward the shank 300, i.e., a groove tail end 232, and the other end extends to the drill tip 100, i.e., a groove front end 231. The junk slots 230 are straight slots or spiral slots from the leading slot end 231 to the trailing slot end 232. The PCD wafer 500 is disposed on the junk slots 230 and on the first and second cylindrical bars 210, 220, respectively.

Typically, at least one flute, and more typically at least two flutes, are provided on the drill body 200. In fig. 3, at least 2 junk slots, namely, a first junk slot 233 and a second junk slot 234, are provided in the drill body of this embodiment. A first PCD wafer 510 is disposed on the flute face of the first junk slot 233 and a second PCD wafer 520 is disposed on the flute face of the second junk slot 234 on one side of the longitudinal axis 400 for machining into a one-sided main edge on the drill tip. One end of the first PCD wafer 510 is used to form the other side major and chisel edges on the drill tip 100, with the side of the end adjacent the longitudinal axis 400 extending toward the longitudinal axis and beyond the longitudinal axis 400 so that the longitudinal axis 400 is on the PCD wafer.

The ratio of the distance D of the edge furthest 511 of the first PCD wafer 510 from the longitudinal axis 400 across the longitudinal axis 400 to the diameter D of a circle intersecting a radial plane with the drill body is between 5% and 20%. The first PCD wafer 510 has a PCD layer thickness exceeding the chisel edge width of the cutter.

When the PCD drill bit of the present embodiment is used for forming holes of various nonferrous metals including copper, aluminum and alloys thereof (such as zinc-copper alloy, nickel-copper alloy, tin-copper alloy, magnesium-aluminum alloy, silicon-aluminum alloy, etc.), the front end chisel edge of the whole drill bit is made of PCD material in the width direction, thereby improving the wear resistance of the drill tip without the cutting edge point, and remarkably prolonging the service life of the tool compared with the multi-step hole machining tool of the hard alloy drill tip, as shown in tables 1 to 3.

TABLE 1

TABLE 2

TABLE 3 Table 3

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Claims (10)

1. A PCD drill bit comprising an elongate body member having a longitudinal axis, a shank mountable to a rotary machine, a drill body, a drill tip, a first junk slot and a second junk slot, wherein a first PCD wafer is disposed on a face of the first junk slot and a second PCD wafer is disposed on a face of the second junk slot, the second PCD wafer being located on one side of the longitudinal axis for machining into a side major edge on the drill tip; the first PCD wafer is adapted to be machined into the other side major and minor edges of the drill tip, with one end of the PCD wafer extending toward the longitudinal axis adjacent one side of the longitudinal axis and beyond the longitudinal axis such that the longitudinal axis is located on the PCD wafer.

2. The PCD drill bit of claim 1, wherein the first PCD wafer has a PCD layer thickness exceeding the chisel edge width of the cutter.

3. A PCD drill bit as claimed in claim 1, wherein the ratio of the distance of the side of the first PCD wafer furthest from the longitudinal axis beyond the edge of the longitudinal axis to the diameter of a circle intersecting a radial plane with the drill body is in the range 5% to 20%.

4. The PCD drill bit of claim 1, wherein the ratio of the distance of the side of the first PCD wafer furthest from the longitudinal axis beyond the edge of the longitudinal axis to the diameter of a circle intersecting a radial plane and the drill body is 10 percent.

5. The PCD drill bit of claim 1, wherein the junk slots are in the form of straight slots, or slots in the form of spirals.

6. The PCD drill bit of claim 1, wherein the bit body is machined from a piece of cylindrical metal material.

7. A PCD drill bit as claimed in claim 1, wherein the chip grooves are provided in a stepped bar of cylindrical metal material of several diameters joined end to end, one chip groove being provided in several cylinders of different diameters, forming the drill body, and the PCD wafer being provided in these cylinders of different diameters with only one drill point.

8. The PCD drill bit of claim 1, further comprising a third junk slot disposed in the drill body.

9. The PCD drill bit of claim 1, further comprising a plurality of flutes disposed on the drill body such that the total number of flutes is greater than 3.

10. The PCD drill bit of claim 1, wherein the PCD wafer comprises a laminate of two materials, a substrate layer and a PCD layer, the substrate layer being formed from a metallic material, the PCD layer being located on the substrate layer, the substrate layer being bonded, sintered or welded to the junk slots.

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