MXPA96005559A

MXPA96005559A - Improved superabrasive tool

Info

Publication number: MXPA96005559A
Application number: MXPA/A/1996/005559A
Authority: MX
Inventors: S Fisher Kawika
Original assignee: Norton Company
Priority date: 1994-05-13
Filing date: 1995-01-28
Publication date: 1998-02-01

Abstract

The present invention is related to an abrasive tool comprising a core and abrasive segments attached to said core wherein said abrasive segments comprise a bond material and superabrasive grains and wherein said segments comprise at least two circumferentially spaced regions and wherein said superabrasive grains are alternately dispersed in said regions in high and low concentrations of superabrasive grains. The present invention is further related to an abrasive tool comprising a core and abrasive segments attached to said core wherein said abrasive segments comprise a bond material and superabrasive grains, wherein said abrasive segments comprise at least two circumferentially spaced regions and wherein said superabrasive grains are alternatively dispersed in every other region.

Description

f ° - IMPROVED SUPERABRASIVE TOOL BACKGROUND OF THE INVENTION The present invention relates to superelevating devices such as wheel segments < They comprise a grain surpassing vo - (as diamantle, nor + boron boron ruride (CBN) or boron sulfoxide (RxO).

Lf) REVIEW OF TECHNOLOGY Conventionally, ol corle of hard materials - such as granite, marble, filled concrete, asphalt and the like - is achieved with the use of superabras saw blades. These segmented saw blades **; They are well known. The blade comprises a circular steel disc having a plurality of spaced segments. Tool segments contain superabrasive gages randomly dispersed in an ina-t i, * of ine + al The performance of these segmented tools is measured by examining the cutting speed and the life of the tool. The cutting speed is an inedLda of how fast a given tool cuts a particular type of material, while the tool's v value is the cut-off life of the ho a. '5 Disabling-undainently, the performance of these abrasive cutting tools requires more or less of a change in the overall nature of the blades. Most of them have a shorter life, while longer lifespans are very simple, with conventional sheets this is because the matrix that holds the abrasive grain has a great impact on the cutting speed and life of The sheet With metal adhesives, for example, a matrix that lasts as an iron adhesive, retains better abrasive grains, improving the path of the blade. f) of each individual abrasive grain allowing it to become dull and thus reducing the cutting speed. Contrary, for example, to a larger matrix, such as a bronze adhesive allows the abrasive grains to be detached from the ma , thus improving the cutting speed. This The value of each abrasive grain decreases, allowing the exposure of new, pointed abrasive grains more quickly on the surface of the lower part, Therefore, the object of the present invention is to produce a segmented pebble tool. where both the cutting speed and the life of the tool are improved. A further object of this invention is to produce a superabrasive segment in which the super-abrasive grains concentrate preerencly to achieve these results.

BRIEF DESCRIPTION OF THE INVENTION The present invention was based on an abrasive tool that comprises a core and abrasive segments attached to this core, wherein said abrasive segments comprise an adhesive material and superabsorbent grains, and wherein said segments comprise the minus two regions rcunferencialment space and said grains -, u? eral > ras? They are scattered alternately in these regions in high and low concentrations of superabrasive grains. The present invention also relates to an abrasive tool comprising a core and abrasive segments attached to this core, wherein said abrasive segments comprise an adhesive material and super abrasive grains, and wherein said abrasive segments comprise at least two spaced regions eircum referentially and said superoblas grains are variably dispersed in every two regions.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a fragmentary side view of a segmented adhesive saw blade constructed with segments of the present invention. Figure 2 is a perspective view of an abrasive segment of the present invention with regions < ~ > The circumferential borders are where the superobranial grains disperse to. i ernat varnei'it e in every two re ione. Figure 1 is a perspective view of an abrasive segment of another embodiment of the present invention with spaced apart regions and wherein said pebbles are alternately dispersed in said regions of high and low grains. suérabical * DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an abrasive tool comprising a core and open segments attached to this core, wherein said abrasive segments comprise an adhesive material and superabrasive grains and wherein said abrasive segments comprise at least two spaced regions Circumferentially and said perennial grains are either dispersed alternately in each two regions or alternatively dispersed in the regions at low and high superabundant grain concentrations. The core of the abrasive tool can be made of a resin, a ceramic or a metal. Abrasive segments are attached to the core that are made of an adhesive material and superabrasive grains. The abrasive tool can be, for example, a tubular auger or a cutting saw. Xlu to 1, preferred embodiment of the present invention, is a rotating abrasive wheel or saw blade 10. The abrasive wheel 10 has a support, center or pre-urinated metal disc 1, which includes a wall of predetermined diameter and thickness usually made of steel. The steel centreline 12 has a contiguous orifice 14 adapted to receive a drive means or wick of a machine on which it is to be rotated and rotated. Extending radially towards the outside peripheral surface of the support center 12 there is a ** plurality of radial grooves 15 and supporting sections l intermediate abrasive segments IR of the wall, including abrasive segments 20 thereon, angled at near the center e. The segments may be reinforced with a portion of non-cutting metal 28 as shown in Fig. 2 with a fitted inner surface. Each section of abrasive segment support 18 has an outer perimeter surface adapted initially. to locate an adjusting hinge with an inner surface of the preformed abrasive segment 20 during beam fusion welding, electron beam fusion welding or brass welding, from the same to the support section 18 of the metal support wall. The abrasive segments 20 may comprise at least two spaced apart regions where the superabrasive grains are dispersed alternately in each of two regions, see FIG. 2, or may comprise at least two spaced ions. < I assembled in which the superabrasive grains are dispersed alternately in the high regions and the concentration of superabrasive grains, see figure 3. The preferred modality is where the abrasive grains are alternately dispersed in every two legions and is shown in Figure 2. As can be seen in Figure 2, the abrasive segment 20 is divided into regions with abrasive grains dispersed alternately in each regions, regions containing abrasive grain are marked as 1, 3 and 5 in this example and alternate with regions containing only adhesive, which are marked as 2 and 4. Preferably, there are from 3 to 25 regions approximately per abrasive segment and most preferably from about 7 to 15 regions. Although in the preferred embodiment, the individual regions through an abrasive segment such as for example the regions 1, 2, 3, 4 and 5 shown in Figure 2 are the same dimensions, for the purposes of the present invention it is not It is necessary that these regions be of equivalent size. Depending on the application and the end use, these regions can be varied to improve the properties of the abrasive wheel in a particular application. However, it is preferable that the region at the projecting edge of the segment contains abrasive grain. This structure for a segment allows a higher-speed cutting and longer tool life to the same < - mpo. Because legions with less abrasive or less tend to be softer, this portion of the segment tends to become faster, exposing those regions that have the highest diaphragm concentrations in the abrasive segment. . An abrasive segment with a smaller contact area tends to cut quickly, and regions on high diamond concentration will experience less wear due to the higher concentration. Another variation of this invention is shown in ^ * - "Figure 3, in which the concentration of superabrasive grains varies continuously between legions or disconcutaneously with a sudden drop in concentration between regions .. concentrations of superabrasive grains vary continuously between regions of the abrasive segments, then can be determined the limits of the regions with high and low concentrations with the following m all. First, the minimum and maximum concentrations of abiasive grains are measured through the abrasive segment. This is done by measuring the percentage of rea to t 'birds of a segment by continuously measuring the concentration by intervals of 1 inm, and establishing the center point of the minimum and maximum intervals. An artificial limit is created by dissecting the area of the central points of the adjacent minimums and maxima in the upper concentration. Each region is defined in the volume between adjacent artificial boundaries and is called, for the purpose of * * speciication, a defined region. Although the con < The diamond ratio in the abrasive segment is a slow volume pore (which is calculated by dividing the volume of superabrasive grain in the abrasive segment by the volume of the total abrasive segment), the high and low concentration regions are defined or follow. The regions of al to concentration are those regions that were previously defined where the concentration of superabrasive grains is greater than 2 X percent by volume of the total defined region, preferably greater than X percent by volume and much greater than 8 X percent in volume ,. Regions of concentration are those regions as defined above where the concentration of superabrasive grains is less than 0.5 X percent by volume of the total defined region, preferably less than 0.25 X pore slow in volume and very low in water. 0.12 X percent by volume. If the concentrations of superabundant grains progress substantially discontinuously or discretely in the regions of the abrasive segment, then the boundaries of the regions are defined as this drop in discontinuous or discrete concentration. A discontinuous or discrete drop in concentration is defined in an abrasive segment with a total concentration of X percent by volume or a fall of 2 X percent by volume in concentration by a region of the segment, and I preferrely prefer a fall in volume. 4 X in volume in concealment for a segment of 1 mm of the segment, the regions can again be measured by measuring the center point of this discrete discontinuous drop in concentration through the abrasive segment and considering this center point as the limit of adjacent regions. In a preferred embodiment, the adhesive of the segment is a metal adhesive 25. These metal adhesives 25 and the non-cutting metal portion 28 comprise, for example, metal materials such as cobalt, iron, bronze, nickel alloy, tungsten carbide. , chromium boride and mixtures thereof. The adhesive can also be a glass or a ream to adhere with resin or vitrified cores. Reagent segments contain approximately 1.0 to 25% by volume of superabrasive grain and are preferably from 3.5 to 1.5% by volume, approximately. The average particle size of the superabrasive grain is preferably from LOO to about 1200 microns, preferably from 250 to 100 microns, and most preferably from about 300 to 650 daughters, secondary abrasives can be added to the segments. For example, tungsten carbide, alumina, alumina sol-gel, silicon carbide and silicon trunnion, these abrasives can be added to regions with higher concentrations of superabrasives or to regions with low concentrations of superabrasives. preferably molding and LO Inane ndo. The abrasive segments are molded in a two-stage pi-cocodimion. Fn The first stage, a mold is filled with a cavity that has depressions for the regions of the segment containing high concentrations of superabraviso, and a depression for the portion of non-sharp metal 28. First, the depressions will hold the regions that contain more concentrations. High pebbles are filled with a mixture of metal adhesive powder and superabrasive grains, then when these depressions are completely full, metal powder that does not contain abrasive is used to fill the depressions for the metal portion. not cutting. Then the mold is baked at a temperature below the melting point of the metals used to make the mixture in the mold. The concreted body is then removed from the mold and then placed in the mold with a cavity in the shape of the segment. This creates depressions among the legions that contain the highest concentrations of superabrasive grains. These depressions are then filled with loose powder containing a low concentration of superabrasive grain, or not with Lene. The mold is then baked under pressure at a certain time, temperature and pressure to achieve theoretical density greater than 05% and [r] erily greater than 95% theoretical density. These segments can also be produced by strip casting, injection molding and other techniques known to those in the art. In order that the experts in the atei may better understand the practice of the present invention, the following examples are provided by way of illustration and not by way of limitation. Additional information that may be useful in current practice of the art can be found in each of the references and patents cited herein, which are incorporated herein by reference.

EXAMPLES Example 1 Two sheets are analyzed to determine cutting speed and wear. Both blades have abrasive segments containing 4% by volume of diamond with synthetic metal adhesive (grade SDA100) The blades are 40.64 crn in diameter and have a cutting edge (groove) of 0.38 cm. The diamond abrasive used on both sheets is diamond grit 30/40 (429-550 u) .The diamond abrasive is randomly dispersed in the segments used for the control sheet. The segments in the present invention contain six diamond-containing regions separated alternately by 5 regions that do not include abrasive.The matrix in the diamond-containing regions are <V * "'* n alloy containing about 45% in iron ore. and 55% by weight of bronze.The rnatiiz in the non-abrasive containing regions are of bronze adhesive.The diamond abrasive is dispersed in 6 regions containing 5 diamond in an iron-alloy matrix. eleven. The sheets are tested on a cured concrete plate with granite aggregate reinforced with a 1.27 cm reinforcing bar. The sheets are tested at a constant cutting speed of 24 minutes, and are used to cut the concrete. HE adjust The cutting speed will be the maximum cutting speed of the control sheet. This is done by adjusting the cut speed of the control sheet just at the point where the motor would be stuck (with the circuit to be set to fire at 10 I w). The sheet of the present invention is run at 24.03 cm- 15 meters / minute even if a higher cutting speed could be used. The measurements show that the contour sheet L uses 0.0339 cm while the sheet with the abrasive segments of the present invention uses 0.0091 crn. This test proposes a improvement of over 350% in the life of the sheet over the conventional sheets, at the highest cutting speed the conventional sheet will trust.

? * "L "** Example 2 Or the sheet comparison method includes the concrete chute without cooler at constant feed rates. The test used includes the det ernination of the number of cuts to the fault. In this example, the sheets of the present invention are compared with control sheets. All three sheets are 22.86 cm in diameter with a cutting path (slot) of 0.241 em. The segments of all the sheets contain 3.5% by volume of diamond. The diamond abrasive used on all sheets is diamond grit 30/40 (429-650 u). The segments of the control sheet known as pattern No. 1 use an adhesive that contains 100% cobalt. The segments of the control sheet known as pattern No. 2 use an adhesive containing 60% by weight of iron, 25% by weight of bronze and 15% by weight of cobalt. The abrasive diamond is randomly dispersed in the used segment: the control sheet. The sheet made with segments of the present invention contains 5 diamond-containing regions separated alternately by 4 non-abrasive regions. The matrix in the diamond regions is an alloy containing approximately 45% by weight of iron and 55% by weight of bronze. The matrix in the regions that substantially do not contain abrasive is of bronze adhesive. Diamond abrasive EJ is dispersed in the 6 regions containing diamond in an iron-bronze alloy matrix.

*** • L * ', leaves are run on a trestle saw from b (.force belts model No. 54 LC, manufactured by Saw ing Systems of Knoxville, TN) The sheets are run at approximately 5800 rprn.The subtacts to be cor- rolled by the blades are exposed 5-slabs of 30.48 cm x 30.48 crn x 5.08 crn, Jas cua They contain from 0.635 crn to 1.27 ein of river gravel in cement of 252 kg / c2 n 2. It is considered that this medium is hard to very hard. indicates the number of passes the blade makes before the automatic switch trips. For the test, the automatic switch is set to 2.0 HA). Each step of the saw cuts three blocks at 2.54 ein depth of cut at a constant feed rate of 88.4 crn / inin. Higher energy requirements indicate that the sheet is not cutting e ciently. As shown in Table I, the leaves of the present invention never faltered, but the test was finished at approximately twice the number of corners of the normal sheet of better performance. twenty ? Fü TABLE I Example 3 In a concrete wall coring field test with wall saw blades, the new abrasive segments are compared to a normal blade known as the Cushion Cut US40 made by Cushion Cut of Hawthorne, CA. Both sheets are 60.96 cm in diameter with a cutting path (groove) of 0.475 crn, and are tested in a 20 horsepower hydraulic wall saw. The segments of the control sheet use an adhesive alloy of 50% iron and 50% bronze. The volume fraction of the diamond is 5.00%. Used diamond abrasive EJ is diamond grit 30/40 (429-650 JJ). The diamond abrasive is randomly dispersed in the segments used for the control line. The segment made with segments of the present invention contains regions that have diamonds separated alternately by 5 regions that do not contain abrasive. The matrix in the regions containing diamond is. { H ~ alloy containing approximately 45% by weight of iron and 55% by weight of bronze. The matrix, in the regions that sstabase alíñente does not contain abrasive is of bronze adhesive. The fraction of diamond volume is 4.00%. The diamond abrasive used is grit from dLamante 30/40 (429-650 μ). The diamond abrasive is dispersed in the 6th diamond containing a diamond in an iron-bronze alloy matrix. The result shows that the saw blade containing the abrasive segments of the present invention has a cutting speed of 41.89 cin-meters / minutes (based on the total cut-off time) with a usage performance of 25.79 ern-meters / 25.4 u of wear. While the control sheet with a comparable diamond content has a cross-section speed of 8.38 cm-inetr / null (based on the total cut-off time) with a usage performance of 145.78 ein-meters / 25.4 μ of waste e.

Example 4 In another field test of concrete wall cutting with wall saws blades, the new open segment is compared to a normal wall known as the U35 Dimas made by Dirnas Industries of Princeton, IL. Both sheets are 60.96 cm in diameter with a cutting path (grooves) of 0.559 cm, and are tested in a hydraulic wall saw of 36 horsepower.

L7 The segments of the contiol sheet use a bronze cobalt adhesive. The fraction of diamond volume in the segment is 4.875%. Used abrasive diamond FL is 40/50 diamond grit (302-455 urn). The diamond abrasive is randomly dispersed in the segments used for the control sheet. The sheet made with the segments of the present invention contains 6 regions which have diameters separated from the surface by 5 regions which are not abrasive. The matrix in the regions containing diamond is an alloy that contains approximately 45% by weight of iron and 55% by weight of bronze. The matrix in regions that substantially contain no abrasive is copper adhesive. The fraction of diamond volume in the segment is 4.00% which is dispersed in the diamond-containing regions. The diamond abrasive used is diamond grit 30/40 (329--650 urn). The abrasive diamond is dispersed in the 6 diamond-containing regions in an iron-bronze alloy matrix. The sheets are tested on a cured concrete wall 38.1 cm thick that is being cut for demolition. The wall was made of concrete of approximately 432 l-g / crn * with soft aggregate torque. The concrete was reinforced with two layers of 1.27 mm of reinforcement bar in centers of 30.48 cm both horizontally and vertically. A 36 horsepower hydraulic saw is used to cut the wall.The results show that the saw blade which has the open segments of the present invention has a cutting speed of 19.54 kin-meters / i (based on the total cutting time). <; On a usage performance of 462.98 crn rnetro / 25.4 μ of wear, the framing sheet with a comparable diamond content has a cutting speed of 14.58 cm-min / min (based on the total time of cut) with a usage performance of 197.05 cm-met ro / 25. μ of d s ast e. It is understood that other different modifications will be clear and can easily be made by those skilled in the art without departing from the scope and spirit of this invention. Therefore, the scope of the annexed clauses is not intended to mimic the description of the examples set forth above, rather than the claims being constructed to encompass all the patentable novelty characteristics that reside in the present invention, including those features that could be dealt with or equivalents thereof by those skilled in the art to which the invention pertains.

Claims

THE NOVELTY OF THE INVENTION CLAIMS

1. - An abrasive tool (Figure 2) comprising, a) a core (12) having a plurality of peripheral surface sections (18) defined by radial grooves in the core (12), and b) a plurality of segments The abrasive (20) bonded to the peripheral surface sections (18), each abrasive segment (20) comprises abrasive grain having an average particle size of 250 to 900 μm and adhesive material, and has a protruding edge and by at least one group of first and second regions alternating filar-alleles (1, 3, 5 and 2, 4) arranged transversely The peripheral surface sections (18) where the first regions (1,3 and 5) have abrasive grain, and the second. regions (2 and 4) are substantially free of open grain.

2. The abrasive tool according to claim 1, further characterized in that the abrasive segments contain a metal adhesive.

3. The abrasive tool according to claim 2, further characterized in that the abrasive segments further include a secondary abrasive.

4. - The abrasive tool according to claim 1, further characterized in that the core is < »/ H: group of the group consisting of thesis, ceramics and metal.

5. The abrasive wound according to claim 1, face < t also because the abrasive tool is a cutting saw.

6. An abrasive tool (Figure 3) comprising a core (12) having a plurality of peri-surface surface sections (18) defined by radial grooves in the core (12), and b) a plurality of segments bonded abrasives the peripheral surface sections (18), each abrasive segment comprises abrasive grain and adhesive material and has a protruding edge in at least one group of first and second parallel alternating regions disposed transversely to the peripheral surface sections (18) where the percentage by volume of the abrasive grain at a central point of the region is at least twice the volume percentage of abrasive grain at a central point of the second region, and the segment thus claimed is united to the peripheral surface sections (18) by means selected from the group consisting of laser beam fusion welding, electron beam fusion welding and brass welding.

7. The abrasive tool according to claim 6, further characterized in that the abrasive segments have a metal adhesive.

8. The abrasive tool according to claim 7, further characterized by the fact that the elements include a secondary abrasive 9.

The abrasive tool in accordance with the re fi l ication, also characterized because the core is selected from the group consisting of foam, ceramic and metal ..

The abrasive tool according to claim 6, also characterized by the fact that the abrasive tool is a cutting saw.

11. An abrasive tool (as exemplified in FIG. 2) comprising a core (12) having a plurality of peripheral surface sections (LO) defined by radial grooves in the core (12), and (b) a pLurality of abrasive segments (20) attached to the peripheral surface sections (18), each abrasive segment (20) comprises an abrasive gr and an adhesive material, and has a protruding edge and at least 7 alternating first and second regions parallel (for example 1.3 5, and 2, 4) arranged crosswise to the peripheral surface sections (10) wherein the first regions (1,3 and 5) contain open grain and the second regions (e.g. 2 and 4) are substantially free of abrasive grain.

12. The abrasive tool according to the indication 11, characterized furthermore because the abrasive elements contain a metal adhesive.

13. The abrasive tool according to claim 12, further characterized in that the abrasive elements include a secondary abrasive. 1

14. The abiasive tool in accordance with claim II, further characterized because the core is selected from the group consisting of resin, ceramic and inet L. 15- The abrasive tool according to claim 11, furthermore Because the abrasive tool is a cog saw.