WO2002066217A1

WO2002066217A1 - Machining tips and cutting wheel, grinding wheel and drilling wheel therewith

Info

Publication number: WO2002066217A1
Application number: PCT/KR2001/000938
Authority: WO
Inventors: Changhyun Lee
Original assignee: Ehwa Diamond Ind. Co., Ltd.
Priority date: 2001-02-20
Filing date: 2001-06-01
Publication date: 2002-08-29
Also published as: KR100414006B1; KR20020068171A

Abstract

The present invention relates to a machining tip and a cutting, grinding and drilling wheel equipped with those machining tips.

Description

MACHINING TIPS AND CUTTING WHEEL, GRINDING WHEEL AND

DRILLING WHEEL THEREWITH

TECHNICAL FIELD The present invention relates to machining wheels for cutting, grinding and drilling materials such as stones, concrete or the like and machining tips to be mounted on such machining wheels, and more particularly to machining tips in which superabrasive and adhesive are uniformly distributed and by which the machining precision and the cutting performance of tools can be improved as well as a cutting wheel, grinding wheel and drilling wheel including those machining tips .

The adhesive called as such in this specification refers to sintered matter of metal powder for retaining diamond particles and allowing the self-regeneration of diamond particles and may be called as binding agent in cases.

BACKGROUND OF THE INVENTION

Generally, for cutting or grinding an object with a high strength and hardness like stone, metal or the like, a cutting or grinding tool including a material having a high hardness such as the diamond or cubic boron nitride (CBN) is used.

Among those tools for cutting or grinding, as the tools capable of cutting, grinding or drilling the objects including the stones, concrete and the like, three representative tools may be mentioned as follows .

That is, they are the saw blade usually in the form of a disc for conducting cutting operation, the grinding wheel usually in the form of hemisphere for conducting grinding operation and the core drill generally in the form of a cylinder for conducting drilling operation.

Generally, the machining tips mounted on those three kinds of tools include the segment type tips as shown in Figure la, which are mounted on a tool in a plurality and the rim type tips not shown for use as a continuous form. There are also the turbo type tips as shown in Figure lb, which include raised and depressed side walls . A saw blade is fabricated by fixing the machining tips produced by mixing, compacting and sintering diamond particles and adhesive on the circumferential edge of a steel disk by means of welding, wherein the exposed diamond particles on the rotating blade are put to use mainly for .cutting an object. A grinding wheel which is usually in the form of a semi- dome is provided with machining tips around its outer circumference for planning stone material or the like.

Further, the above described core drill is a tool for making a hole in various materials like concrete, asphalt or stone and comprises a hollow shaft equipped, at one end of the shaft, with machining tips particularly suited for conducting drilling operation on finished buildings in engineering and constructing sites without giving a big impact or structural damage . As the suitable material for the machining tips mounted on tools as described above, in most cases the diamond is used for direct cutting and grinding but alternatively high- hardness materials including the cubic boron nitride (CBN) may be used.

Such conventional machining tools and machining tips mounted on the tools will be described in detail in conjunction with the corresponding drawings. Figure la shows the perspective view of a segment type machining tip and Figure lb shows the perspective view of a turbc type machining tip for cutting and grinding according to a conventional art. Figure 2 shows the constructional view for a cutting wheel provided with the machining tips as shown in Figure 1, Figure 4 shows the constructional view for a grinding wheel provided with the machining tips as shown in Figure 1, and Figure 3 shows the constructional view for a core drill provided with the machining tips as shown in Figure 1, all concerning a conventional art. All of these drawings show only the segment type tips and so neither the rim type nor turbo type is shown.

As shown in Figures la, lb, 2, 3 and 4, the conventional machining tip is substantially in the form of a hexahedron curved with a predetermined radius of curvature in longitudinal direction.

The machining tips 1 are the part directly brought into contact with an object for grinding or cutting and made by a process including the processes of mixing fine particles of diamond or cubic boron nitride as the abrasive agent and metal powder as the binding agent and sintering the mixture in a desired form.

The thus-completed machining tips 1 fixed on a cutting wheel in the form of disk 3 provides a saw blade, as shown in Figure 2, which can perform cutting work on a hard material, given a rotating power.

The machining tips 1 are fixed on the outer circumference of the cutting wheel 3 at a predetermined interval by means of soldering, welding, sintering-diffusion-joining or the like.

When machining tips 1 are mounted on a wheel 5 in the form of a hemisphere or dome, as seen in Figure 3, a grinding wheel results to be used for grinding or polishing the whole or part of the surface of a hard material, wherein the machining tips 1 are fixed on the wheel by means of soldering, welding, sintering-diffusion-joining or the like as well.

In about the same way as above, a core drill comprising a cylindrical wheel 7 equipped with machining tips 1 is produced as shown in Figure 4 to be used, for making a hole at a particular area of an object in a rotational drilling operation. The fixing method of the tips to the wheel is the same as in the above .

On the other hand, during the process of mixing the superabrasive like diamond or CBN particles with the metal binding powder, the abrasive particles have a much larger size compared to the metal powder and substantially symmetric shape and so tend to freely flow, so that under the condition of a finite overall blending ratio of the abrasive to the metal powder, the abrasive particles are locally concentrated or segregated to cause irregular or non-uniform distribution within the machining tips 1.

Even if a uniform mixing was attained by using specially devised method or means in bulky state in the main mixer, the uniformity is easily broken in the course of transferring to a small container or to a mold for compacting machining tips 1.

Resultantly, within the machining tips, the superabrasive may be highly concentrated in a certain region or very deficient below the average concentration in other parts.

On the other hand, a cutting or other machining tool rotating at a certain speed removes the surface parts of stone or concrete with the torque originating from the operating motor and during the course, the superabrasive particles on the machining tips experience severe load due to the reactive force of the object in the form of. friction, specially impact force, with the result that the superabrasive particles can be worn out, loosened or even broken.

In particular, when such load of friction with the object exceeds the force binding the metal powder with the superabrasive particles mechanically and chemically or the retaining force of the binding agent, the abrasive particles pull out and newly emerging particles, in fact deeply located particles, take over the machining duty, and thus in such a manner self-regeneration process repeats itself to enable continuation of machining operation including cutting, grinding and drilling with the depleted thickness of machining tips .

In the case the superabrasive particles are segregated to certain locations, the impact or friction load imposed on an individual particle under a finite torque would be decreased.

However, during initial time after the start of cutting or grinding, the superabrasive particles would be in active working and so dulled in the sharp tips or can be subjected to a degradation together with the binding material due to an abrupt frictional heat generation, however the self- regeneration remains at a low level, so that deformation or unevenness on the surface of steel wheel 3 can result.

In contrast, the superabrasive particles in the area of the machining chips 1 where the concentration of superabrasive particles is relatively low are subjected to larger load of friction or impact per unit particle and therefore the superabrasive particles are easily broken, constituting a cause of decreasing the service life of the machining tool.

Further, in the case of a material like granite or marble which has a high hardness and relatively low toughness and so is apt to be crackable, the chipping phenomena in which the material is broken at the corner portions of side walls take place, causing the decrease in the quality of machined material .

In a PCT patent application corresponding to US patent No. 6,039,641 to C. M. Sung, a Taiwanese, methods for manufacturing a saw blade, wire saw, grinding wheel and so on are described.

According to the disclosure, a sieve patterned in a regular arrangement is placed on the molded body of the metal powder having the particle size over a certain value and subsequently superabrasive particles are passed through the sieve to be fixed on the molded body, in order to maximize the working performance of the superabrasive particles .

In the next step, the superabrasive particles together with metal powder acting as the adhesive are caused to sinter to firmly fix the superabrasive particles mechanically and chemically, so that mono or plural layers of superabrasive on the same plane may be formed. The tools by such a method have, however, a very limited practical application, for example, as grinding wheels or wire saws provided with abrasive layers only on the surface, because the method can provide only one or a few layers at most of superabrasive particles in the machining tips of the segment form.

Moreover, the service life of. a tool is relatively short due to the limited thickness of superabrasive bed and the cutting performance is inconsistent over the service time as the particles of superabrasive are getting dull, ending with abrupt drop in the cutting capability.

SUMMARY OF THE INVENTION

Therefore, the present invention was created to resolve the problems with the conventional art as described above, and the object of the invention is to provide a machining tip and a cutting wheel, grinding wheel and drilling wheel equipped with the machining tips, which allow precise cutting, grinding and drilling work thanks to the uniformly distributed superabrasive and which make possible the marked improvement in the service life of tools.

Formation of a machining tip which includes matrixes each consisting of superabrasive particles and the binder so as to realize a uniform arrangement of superabrasive particles over a whole machining tip is also sought.

The object is achieved according to an aspect of the invention by machining tip, comprising: matrixes comprising superabrasive particles and binder powder and having a uniform cross section in one direction; and a frame enclosing matrixes for holding the matrixes at predetermined distance, with the end cross section of the matrixes exposed.

Preferably, said frame is in the form of a segment or rim. The frame is preferably in the prominence-and-depression or turoo form.

The cross section of the matrix may be preferably in the form of a circle, or n the form of a quadrangle.

Preferably, said superabrasive comprises the diamond or cubic boron nitride.

The object is also achieved according to another aspect of the invention by a cutting wheel, comprising: machining tips each comprising matrixes comprising superabrasive particles and binder powder and having a uniform cross section in one direction, and a frame enclosing matrixes for holding the matrixes at predetermined distance, with the end cross section of the matrixes exposed; and a driving wheel equipped with two or more machining tips symmetrically around the circumferential area of the wheel. Preferably, the frame is in the form of a segment.

Otherwise, the frame may be preferably m the form of a rim. Or the frame may be m the turbo form.

The cross section of the matrix may be preferably in the form of a circle, or a quadrangle.

Desirably, the superabrasive comprises the diamond or cubic boron nitride.

The object is also achieved according to another aspect of the invention by a grinding wheel, comprising: machining tips each comprising matrixes comprising superabrasive particles and binder powder and having a uniform cross section in one direction, and a frame enclosing matrixes for holding the matrixes at predetermined distance, with the end cross section of the matrixes exposed; and a second type driving wheel in the form of semi-dome equipped with two or more machining tips symmetrically around the circumferential edge area of the wheel.

The object is also achieved according to another aspect of the invention by a drilling wheel, comprising: machining tips each comprising matrixes comprising superabrasive particles and binder powder and having a uniform cross section in one direction, and a frame enclosing matrixes for holding the matrixes at predetermined distance, with the end cross section of the matrixes exposed; and a third type driving wheel in the form of a cylinder equipped with two or more machining tips symmetrically at one end of the wheel.

Other advantages and features of the invention will be obvious from the following description read in conjunction with the accompanying drawings

BRIEF DESCRIPTION OF THE DRAWINGS

Figure la shows the perspective view of a conventional segment type machining tip for cutting or grinding, Figure lb shows the perspective view of a turbo type^' machining tip for cutting or grinding,

Figure 2 shows the view illustrating the arrangement of an ordinary cutting wheel equipped with the conventional segment type machining tips as shown in Figure 1,

Figure 3 shows the view illustrating the arrangement of an ordinary grinding wheel equipped with the conventional segment type machining tips as shown in Figure 1,

Figure 4 shows the view illustrating the arrangement of an ordinary drilling wheel equipped with the conventional segment type machining tips as shown in Figure 1,

Figure 5a shows the view illustrating the arrangement of an ordinary segment type machining tip according to the invention, Figure 5b shows the view illustrating the arrangement of another ordinary segment type machining tip according to the invention,

Figure 6 shows the plan view of an ordinary segment type machining tip according to the invention, Figure 7a shows the perspective view of a matrix according to the first embodiment of the invention,

Figure 7b shows the perspective view of a matrix according to the second embodiment of the invention,

Figure 8 shows the view illustrating the cutting wheel equipped with the machining tips shown in Figure 5,

Figure 9 shows the view illustrating the grinding wheel equipped with the machining tips shown in Figure 5,

Figure 10 shows the view illustrating the drilling wheel equipped with the machining tips shown in Figure 5 and

Figure 11 shows the enlarged view of a major part of the cutting wheel as shown in Figure 8 in operation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The word "segment" as it is used in this specification means a piece or fragment substantially in the form of a sector, particularly used for the purpose of cutting or grinding, the word "turbo type" generally refers to a segment or rim having raised and/or depressed portions or annexes in both directions relative to the width of the rim.

In the present invention, the superabrasive and the adhesive of metal powder are uniformly mixed and sintered to form matrixes which are provided on frames to take the form of a segment or rim and then the segments or rims are mounted on a variety of machining wheels, whereby tools for cutting, grinding or drilling are constructed.

In the following, preferred embodiments of the invention are described in detail by referring to the accompanying drawings .

Figure 5a shows the perspective view of a segment type machining tip 100 and Figure 5b shows the perspective view of a segment type machining tip 100 with a different cross section. Figure 6 shows the plan view of the machining tip shown in Figure 5a, Figure 7a shows the perspective view of a matrix according to the first embodiment and Figure 7b shows the perspective view of a matrix according to the second embodiment . As shown in Figures 5, 6, 7a and 7b, the matrix 10 according to the invention is in the form of a cylinder or bar as a whole and is composed of the binding component comprising metal powder, and as discontinuous phase, the superabrasive including diamond, cubic boron nitride particles or the like.

In the invention, because matrixes 10 only within which the superabrasive is included are distributed in a regular manner in a machining tip 100, the uniformity in the distribution of superabrasive on a machining tip according to these embodiments is superior to a conventional machining tip in which superabrasive particles a e irregularly or randomly distributed over the whole tip.

Accordingly, through the relatively uniform distribution of the superabrasive in view of the overall machining rips, the machining work like cutting, grinding or drilling can be performed by using these blade means more effectively than in the conventional cases.

The formation of a fixed form by the binding material in the form of metal powder together with the superabrasive is made possible by the mechanical and chemical binding force or retention of the binding material for retaining or fixing the superabrasive particles.

On the other hand, as shown in Figures 5 and 6, the matrixes 10 form a machining tip 100 together with a frame 20 in the form of a continuous segment, wherein the frame 10 functions to hold the matrixes 10 in fixed positions, with opposite end faces of each matrix exposed.

This frame 20 is a sintered body of metal powder, in which the superabrasive component is not included or included in much less concentration than in the matrix 20.

The matrixes 10 are arranged in a row in the frame 20 longitudinally to form two or more horizontal rows within a machining tip 100. The horizontal rows of matrixes are arranged in such a manner that the respective neighboring rows have a overlap distance d in the vertical direction as shown in Figure 5.

Accordingly, for example, when the machining tips shown in Figure 5a or 5b as equipped on a steel wheel are put to use as a grinding wheel for grinding operation, the lower rows of matrixes can take over the grinding ^■ work before the rows of matrix positioned just above have been completely worn out., so that self-regeneration may be repeated for a long time. In addition, the frame 20 is exposed to wear more predominately than the matrix portions 10, because the content of the superabrasive in the frame part is much lower than in the matrix parts. Accordingly, a larger extent of matrix bodies get exposed than the frame portion. Accordingly, on the surface of machining tips to be in contact with an object, for example, on two side surfaces and the peripheral surface of each machining tip, as can be understood from Figure 11, plural recesses are formed between the matrixes, which recesses can hold chips or cut scraps of an object being machined produced by the operation of machining tips before they are immediately discharged to the outside, so as to be serve as chip pockets.

Accordingly, as the cut chips or scraps otherwise to remain on an object being machined can be removed to outside almost simultaneously with the proceeding of machining, a precise machining and improved cutting performance can be made possible. Further, plural irregularities formed on machining tips during machining operation due to the difference in the hardness between the matrixes 10 and the frame 20 cause the decrease in the frictional area of the machining tips 100 with the object, so that cutting speed can be improved because of the decreased friction resistance.

In this connection, the above-mentioned irregularities can be formed in advance during the fabricating step of machining tips beside the period of machining operation.

The superabrasive particles like the diamond or cubic boron nitride in matrixes 10 have higher hardness than the binder metal powder, so that the metal powder is worn out earlier during machining work.

As the result, gaps are formed on the matrixes 10 due to the consumed metal powder and so the superabrasive particles underneath can come to expose, as fresh, to the surface of the frame 20 through those gaps. These new abrasive particles can contribute to the improvement of cutting ability, with the sharp blades.

While a segment type machining tip 100 in which the cross section of the matrixes 10 are exposed substantially on the long side wall surfaces of a frame 20 were shown and described, as shown in Figures 5a and 5b, the matrixes may be arranged so that the cross section of the matrixes is exposed at the top circumferential surface of longitudinally curved frame 20. That arrangement depends on the strength, machining position of the object or the like being processed.

In the case of the rim type frame 20 in the form of a circular ring also, the matrixes 10 may be arranged, so that the cross section of the matrixes may be exposed predominately at the outer circumferential edge of the rim type frame 20.

Otherwise, the matrixes 10 can be arranged, so that the cross section of the matrixes 10 may be exposed substantially at the long opposite side surfaces of the frame 20.

Figure 8 shows the view illustrating the arrangement of a typical cutting wheel equipped with the machining tips as shown in Figure 5a, Figure 9 shows the view illustrating the arrangement of a grinding wheel equipped with the machining tips as shown in Figure 5a, and Figure 10 shows the view illustrating the arrangement of a core wheel also equipped with the machining tips as shown in Figure 5a.

Other machining wheels which are equipped with machining tips of rim type or a turbo type as shown in Figure 5b are to fall within the scope of the present invention.

The machining wheel as shown in Figure 8 includes a driving wheel 30 in the form of a circular disk with a predetermined thickness, equipped, around the circumferential edge, with plural machining tips in a segment form in a symmetrical manner. This is a cutting wheel, usually called as a saw blade, which is used for cutting or grinding a hard object such as the stone or the like for building purpose.

Usually, the cutting tips 100 including segment type frames 20 are fixed on the driving wheel 30 by means of a joining process based on silver-lead or laser.

When a saw blade as shown in Figure 8 is driven to rotate, the abrasive carrying plural matrixes 10 which are exposed on both sides and end side of each cutting tip 100 are brought into direct contact with an object to be processed, so that desired cutting work can be carried out.

According to Figure 9, plural machining tips 100 are disposed on a circumferential surface of a second type driving wheel 40 in the semi-dome form at a definite interval in a symmetric manner to thereby provide a grinding wheel 300.

The grinding wheel 300 acts to grind the surface of constructional stone material or the like with superabrasive carrying matrixes 10 on an exposed side of cutting tips 100. In Figure 10, a drilling wheel 400, designated more often as a core drill, which comprises a third type wheel or core 50 in the form of a cylinder with a definite diameter, provided, on one end of the core, with a plurality of cutting tips 100 at regular interval as well. This core drill is used to make a hole or groove with the size corresponding to the diameter of the core 50 in an object including stone, concrete or the like, wherein the matrixes 10 including superabrasive particles protrudent from the surfaces of drilling tips 100 actively take part in drilling work. While the machining tips 100 mounted on the second type driving wheel 40 for grinding and the third type driving wheel 50 for drilling take part in machining work, mainly with the cross sectional areas of the matrix columns 10, the machining tips 100 mounted on the driving wheel 40 for cutting take part in cutting work chiefly with the circumferential edge area of matrix columns 10.

Furthermore, as indicated before, because the superabrasive particles such as the diamond or boron nitride particles are distributed uniformly over the overall machining tips as the result of regular arrangement of matrixes within a frame, machining operation such as cutting, grinding or drilling can be performed precisely and efficiently. Also as indicated in the above, the machining tips 100 can be composed of a rim type frame with a constant thickness beside the segment type frames.

Now, the method for manufacturing machining tips and the cutting wheel, grinding wheel and drilling wheel equipped with the machining tips will be described.

First, superabrasive particles and metal powder binding material are mixed and compacted or sintered into bars or columns with desired size to produce plural matrixes 10.

From metal powder containing no or a trace of superabrasive powder, for example, frames 20 in the form of a curved segment, which are each formed, on the side walls or bottom side, with holes in accordance with the desired arrangement, are compacted and subsequently the matrixes 10 in bar form as described above are imbedded in the holes of the frames 20, so that machining tips 100, as shown in Figure 5a or 5b for example, may be obtained.

Hereupon, if the size of a matrix approaches that of a diamond particle with the increase in the number of matrixes, the arrangement of matrixes within a segment could be ideal in the sense of uniform distribution, based on the control of individual abrasive particle. These arrangement factors for matrixes such as the number, size of matrixes and the like can be decided in consideration of the characteristics of specific applications, difficulty in fabrication of tools, production characteristics and the like.

As next step, machining tips 100 are attached on a driving wheel 30, second type driving wheel 40 or third type driving wheel 50 to complete a cutting wheel 200, grinding wheel 300 and drilling wheel 400.

In the final step, the parts of machining tips 100 to be brought into contact with an object can be ground in advance in consideration of machining direction, so that a number of irregularities are formed on the surface of tips .

On the other hand, the shape of a matrix .10 can be employed, beside the shape of a bar with the cross section of circle or rectangle with round-up corners as described or shown above, from the group consisting of the shapes of a column with the cross section of ellipse, polygon including triangle, quadrangle, or other irregular form, or a cube.

Preferably, a matrix 10 with the cross section of quadrangle including square and rectangle, circle or ellipse may be used. Moreover, the machining tips 100 may be used for the purpose of cutting, grinding or drilling in the field of consumer industry including machining of jewelry or other consumer products in addition to the field of engineering and construction industry as fundamental parts of tools like saw blades, grinding wheels, core drills and so on.

Further, the machining tips as described above may also be applied, beside the segment or rim type frame 20, to a turbo type frame, both side walls of which are formed with prominences and depressions in a zigzag form.

And the manufacturing conditions including sintering, silver-lead, laser welding and the like in the above-described method for manufacturing machining tips and machining tools provided with those tips may be varied to modify their characteristics as the case may be..

There are exhibited various effects and advantages according to the invention, which include, as described above, the improvement in cutting performance and production efficiency through more uniformly distributed matrixes or cutting particles throughout the machining tips, the prolonged service of tools due to overlapped adjoining matrixes in cutting direction and the prevention of chipping phenomena on the material being machined in the case of machining a hard material like granite or marble due to a number of irregularities formed on the machining tips, serving as chip pockets for holding cut chips or scraps only temporarily.

In addition, other advantages are also realized with this invention. In the conventional tool, the area of a segment where the segment is to be welded to a wheel 3 by means of e.g. laser is composed of the steel-based metal including Co, Fe, Ni and the like, but no superabrasive and the blank layer of good weldability with the thickness of a few millimeters. Such a blank layer and the superabrasive particles are apt to fall out due to a lateral load, and could become a source of a risk. However, the segments consisting of matrixes and frames according to the invention can be freed of the problem due to excellent weldability and binding strength and the scattered boundary surfaces between the matrixes and the frame in a segment .

Further, the composition of the metal powder as a segment binder in a conventional diamond cutting tools includes the copper, copper alloy including bronze and brass, tin and/or the like as easily plastic-deformable metals specially in the case of products requiring rapid cutting. Such metal powder falls out easily when the load from friction with an object or impact is increased with the diamond particles getting blunt. Further, because the metal powder is low in hardness, the period of self-regeneration for the diamond gets shorter. Therefore, machining tools including such a soft metal powder binder are widely used for the applications needing high-speed cutting. When such a tool is used in air-cooled manner without cooling water, the metal binder with low fusion point and easily degrading tendency shows burning phenomena, which leads to the change in physical property of the binder as well as thermal oxidation and graphitization of diamond particles, so as to be weak against any shock. Thus, the tool should be cooled enough after every short period of working to function normally. Thus, the workability is damaged. However, for the tool with matrixes embedded regularly in a frame according to the invention, even if some of the matrixes comprising diamond particles and metal binder are thermally damaged, the degradation throughout the overall segment or the burning phenomena can be prevented, because the segment substantially consisting of iron-based material like cobalt, iron and nickel is resistant to heat. Accordingly, sustained dry machining operation is made possible.

There is a still other advantage. In contrast, in the case of cutting the concrete or asphalt containing a great deal of abrasive material like sand or pebble, the metal binder containing a large amount of wear-resisting and high- hardness metals such as W, WC, Cr. or the like was used. In such a case, however, the binder can be easily damaged due to high brittleness, which can cause a segment tip to fall out, endangering the safety of workers. Particularly, when welding by using laser as a heat source, the boundary surface between the blank layer, which comprises substantially iron with good weldability without the diamond or the like and has a thickness of about a few millimeters, and the binder area with a high hardness and brittleness has a tendency to break. This is also the weak place where the diamond distributed nearby can make a crack under a concentrated load. This kind of problem with the conventional art can be resolved by the present invention which employs the segments comprising superabrasive carrying matrixes embedded in the frame for a tool, because an impact is not concentrated to a specific boundary but alleviated through dispersion and further the frame itself is tough and- resistant to impact. Resultantly, the invention can contribute markedly to the improvement of working safety.

It is to be understood that, while the invention was described only with respect to several preferred embodiments, the invention is never restricted to those embodiments and a variety of modifications and alterations would be possible to a man skilled in the art by referring to the description or drawings presented here and within the spirit of the invention and thus those modifications or alterations are to fall within the scope of the invention, which scope should be limited only by the attached claims.

Claims

CLAIMS 1. A machining tip comprising: matrixes 10 comprising superabrasive particles and binder powder and having a uniform cross section in one direction; and a frame 20 enclosing matrixes 10 for holding the matrixes at predetermined distance, with the end cross section of the matrixes 10 exposed.

2. The machining tip according to Claim 1, wherein said frame 20 is in the form of a segment.

3. The machining tip according to Claim 1, wherein said frame 20 is in the form of a rim.

4. The machining tip according to Claim 1, wherein said frame 20 is in the prominence-and-depression or turbo form.

5. The machining tip according to Claim 1, wherein said superabrasive comprises the diamond or cubic boron nitride.

6. The machining tip according to Claim 1, wherein the cross section of the matrix is in the form of a circle.

7. The machining tip according to Claim 1, wherein the cross section of the matrix is in the form of a quadrangle.

8. A cutting wheel comprising: machining tips 100 each comprising matrixes 10 comprising superabrasive particles and binder powder and having a uniform cross section in one direction, and a frame 20 enclosing matrixes 10 for holding the matrixes at predetermined distance, with the end cross section of the matrixes 10 exposed; and a driving wheel 30 equipped with two or more machining tips 100 symmetrically around the circumferential area of the wheel .

9. The cutting wheel according to Claim 8, wherein said frame 20 is in the form of a segment.

10. The cutting wheel according to Claim 8, wherein said frame 20 is in the form of a rim.

11. The cutting wheel according to Claim 8, wherein said frame 20 is in the turbo form.

12. The cutting wheel according to Claim 8, wherein said superabrasive comprises the diamond or cubic boron nitride.

13. The cutting wheel according to Claim 8, wherein the cross section of the matrix is in the form of a circle.

14. The cutting wheel according to Claim 8, wherein the cross section of the matrix is in the form of a quadrangle.

15. A grinding wheel comprising: machining tips 100 each comprising matrixes 10 comprising superabrasive particles and binder powder and having a uniform cross section in one direction, and a frame 20 enclosing matrixes 10 for holding the matrixes at predetermined distance, with the end cross section of the matrixes 10 exposed; and a second type driving wheel 40 in the form of semidome equipped with two or more machining tips 100 symmetrically around the circumferential edge area of the wheel .

16. A drilling wheel comprising: machining tips 100 each comprising matrixes 10 comprising superabrasive particles and binder powder and having a uniform cross section in one direction, and a frame 20 enclosing matrixes 10 for holding the matrixes at predetermined distance, with the end cross section of the matrixes 10 exposed; and a third type driving wheel 50 in the form of a cylinder equipped with two or more machining tips 100 symmetrically at one end of the wheel .