EP2596929B1 - Lame de scie et procédé pour sciage multiple d'aimant à teneur en terre rare - Google Patents

Lame de scie et procédé pour sciage multiple d'aimant à teneur en terre rare Download PDF

Info

Publication number
EP2596929B1
EP2596929B1 EP12194492.0A EP12194492A EP2596929B1 EP 2596929 B1 EP2596929 B1 EP 2596929B1 EP 12194492 A EP12194492 A EP 12194492A EP 2596929 B1 EP2596929 B1 EP 2596929B1
Authority
EP
European Patent Office
Prior art keywords
saw blade
cutting part
lubricant
weight
particle size
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP12194492.0A
Other languages
German (de)
English (en)
Other versions
EP2596929A1 (fr
Inventor
Koji Sato
Yasunori Uraki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shin Etsu Chemical Co Ltd
Original Assignee
Shin Etsu Chemical Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shin Etsu Chemical Co Ltd filed Critical Shin Etsu Chemical Co Ltd
Publication of EP2596929A1 publication Critical patent/EP2596929A1/fr
Application granted granted Critical
Publication of EP2596929B1 publication Critical patent/EP2596929B1/fr
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D5/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor
    • B24D5/12—Cut-off wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
    • B26D1/00—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor
    • B26D1/01—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work
    • B26D1/12—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work having a cutting member moving about an axis
    • B26D1/14—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work having a cutting member moving about an axis with a circular cutting member, e.g. disc cutter
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B1/00—Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B27/00—Other grinding machines or devices
    • B24B27/06—Grinders for cutting-off
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/34—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties
    • B24D3/346—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties utilised during polishing, or grinding operation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28D—WORKING STONE OR STONE-LIKE MATERIALS
    • B28D1/00—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor
    • B28D1/22—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by cutting, e.g. incising
    • B28D1/24—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by cutting, e.g. incising with cutting discs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28D—WORKING STONE OR STONE-LIKE MATERIALS
    • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
    • B28D5/02—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by rotary tools, e.g. drills
    • B28D5/022—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by rotary tools, e.g. drills by cutting with discs or wheels
    • B28D5/029—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by rotary tools, e.g. drills by cutting with discs or wheels with a plurality of cutting blades

Definitions

  • the invention relates to a saw blade for sawing a rare earth magnet block into multiple pieces according to the preamble of claim 1 and to a method of using it.
  • Systems for manufacturing commercial products of rare earth magnet include a single part system wherein a part of substantially the same shape as the product is produced at the stage of press molding, and a multiple part system wherein once a large block is molded, it is divided into a plurality of parts by machining.
  • the single part system includes press molding, sintering or heat treating, and finishing steps.
  • a molded part, a sintered or heat treated part, and a finished part (or product) are substantially identical in shape and size. Insofar as normal sintering is performed, a sintered part of near net shape is obtained, and the load of the finishing step is relatively low.
  • the multiple part system eliminates the above-mentioned problems and allows press molding and sintering or heat treating steps to be performed with high productivity and versatility. It now becomes the mainstream of rare earth magnet manufacture.
  • a molded block and a sintered or heat treated block are substantially identical in shape and size, but the subsequent finishing step requires cutting or sawing. It is the key for manufacture of finished parts how to saw the block in the most efficient and least wasteful manner.
  • Tools for cutting rare earth magnet blocks include two types, a diamond grinding wheel inner-diameter (ID) blade having diamond grits bonded to an inner periphery of a thin doughnut-shaped disk, and a diamond grinding wheel outer-diameter (OD) blade having diamond grits bonded to an outer periphery of a thin disk as a core.
  • ID diamond grinding wheel inner-diameter
  • OD diamond grinding wheel outer-diameter
  • FIG. 1 illustrates an exemplary multiple blade assembly 1 comprising a plurality of saw blades 11 coaxially mounted on a rotating shaft (not shown) alternately with spacers 12, each blade 11 comprising a core 11b in the form of a thin doughnut disk and a cutting part or abrasive grain layer 11a on an outer peripheral rim of the core 11b.
  • This multiple blade assembly 1 is capable of multiple sawing, that is, cutting a block into a multiplicity of parts at a time.
  • diamond grains are generally bonded by three typical binding systems including resin bonding with resin binders, metal bonding with metal binders, and electroplating. These abrasive blades are often used in sawing of rare earth magnet blocks.
  • the relationship of the cutting part (axial) width of the saw blade is crucially correlated to the material yield of the workpiece (magnet block). It is important to maximize a material yield and productivity by using a cutting part with a minimal width, machining at a high accuracy to minimize a machining allowance and reduce chips, and increasing the number of parts available.
  • the abrasive wheel core In order to form a cutting part with a minimal width (or thinner cutting part) from the standpoint of material yield, the abrasive wheel core must be thin.
  • its core 11b is usually made of steel materials from the standpoints of material cost and mechanical strength.
  • alloy tool steels classified as SK, SKS, SKD, SKT, and SKH according to the JIS standards are often used in commercial practice.
  • the prior art core of alloy tool steel is short in mechanical strength and becomes deformed or bowed during sawing operation, losing dimensional accuracy.
  • a cutoff wheel for use with rare earth magnet alloys comprising a core of cemented carbide to which high hardness abrasive grains such as diamond and CBN are bonded with a binding system such as resin bonding, metal bonding or electroplating, as described in JP-A H10-175172 .
  • Use of cemented carbide as the core material mitigates buckling deformation by stresses during machining, ensuring that rare earth magnet is sawed at a high accuracy.
  • high frictional resistance is exerted between the cutting part and the magnet during sawing of the magnet, high accuracy machining is not expected.
  • substantial friction occurs between the side surface of the cutting part (not directly contributing to grinding operation) and the magnet, the grinding resistance is enhanced. Then, even if the cemented carbide core is used, chipping and/or bowing can occur, adversely affecting the machined state.
  • JP2004050331A shows on paragraph [0006] and figure 2 a single super abrasive wheel with hard particles of diamond or CBN for grinding metal, ceramics, glass, plastics, rubber or composite materials, said blade has in the composition of its cutting part lubricant fillers such as hexagonal crystal boron nitride.
  • a blade is not adapted to be stacked in a multiple blade assembly for cutting slices of rare earth magnet and the lubricant particles are of unknown sizes.
  • Patent Document 1 JP-A H10-175172
  • An object of the invention is to provide a saw blade according to claim 1 in the form of a resinoid wheel, which is used in multiple sawing of a rare earth magnet block into multiple pieces, which reduces the sawing resistance between the saw blade and the magnet block, and which ensures sawing at a high accuracy and high speed even if the saw blade is thinner than the conventional blades.
  • Another object is to provide a method for sawing a rare earth magnet block into multiple pieces according to claim 14. Further preferred embodiments are defined by the dependent claims 1-13 and 15.
  • the invention pertains to a multiple blade assembly comprising a plurality of saw blades coaxially mounted on a rotating shaft at axially spaced apart positions.
  • the multiple blade assembly is used for sawing a rare earth magnet block into multiple pieces by rotating the plurality of saw blades.
  • the saw blade has a core in the form of a thin disk or thin doughnut disk and a peripheral cutting part on an outer peripheral rim of the core.
  • the inventors have developed a saw blade in the form of a resinoid wheel having a cutting part made of a composition comprising a component or lubricant for reducing the friction between the cutting part and the magnet block during the sawing operation.
  • the sawing operation experiences a reduced cutting resistance, and achieves an equivalent yield and accuracy compared with the prior art even if thinner saw blades are used.
  • the invention generally pertains to a multiple blade assembly comprising a plurality of saw blades coaxially mounted on a rotating shaft at axially spaced apart positions, which is used for sawing a rare earth magnet block into multiple pieces by rotating the plurality of saw blades.
  • the invention provides the saw blade comprising a core in the form of a thin disk or thin doughnut disk and a peripheral cutting part on an outer peripheral rim of the core, the cutting part being made of a composition comprising an abrasive, a resin binder, and a lubricant for reducing the friction between the cutting part and the magnet block during the sawing operation.
  • the lubricant is boron nitride and is in particulate form having a particle size in the range of 1 to 200 ⁇ m.
  • the cutting part is made of a composition comprising 10 to 40% by weight of abrasive, e.g. diamond and/or CBN, 20 to 60% by weight of structural matrix material, preferably selected from SiC having a particle size of 1 to 100 ⁇ m, SiO 2 having a particle size of 1 to 100 ⁇ m, Al 2 O 3 having a particle size of 1 to 100 ⁇ m, WC having a particle size of 0.1 to 50 ⁇ m, Fe, Ni and Cu having a particle size of 1 to 200 ⁇ m, and mixtures thereof; 10 to 50% by weight of a thermosetting resin as the binder; and 1 to 50% by weight of the lubricant material.
  • abrasive e.g. diamond and/or CBN
  • structural matrix material preferably selected from SiC having a particle size of 1 to 100 ⁇ m, SiO 2 having a particle size of 1 to 100 ⁇ m, Al 2 O 3 having a particle size of 1 to 100 ⁇ m, WC having a particle size of 0.1 to 50
  • the saw blades in the form of a resinoid wheel are used in multiple sawing of a rare earth magnet block into multiple pieces.
  • the saw blade reduces the cutting resistance, improves the sawing accuracy, and ensures sawing at a high accuracy and high speed even if the saw blade is thinner than the conventional blades.
  • the blade is of great worth in the industry.
  • axial refers to the axis of a rotating shaft and "radial” refers to a circular blade in an assembly.
  • the width of the cutting part corresponds to an axial size in this sense.
  • a multiple blade assembly is constructed by coaxially mounting a plurality of saw blades on a rotating shaft at axially spaced apart positions (as shown in FIG. 1 ). The multiple blade assembly is operated by rotating the plurality of saw blades to saw a rare earth magnet block into multiple pieces at once.
  • a saw blade 23 in the form of a resinoid wheel embodying the invention is shown in FIG. 2 as comprising a core 21 in the form of a thin disk (which may be a "doughnut disk", i.e. with a central hole) and a peripheral cutting part 22 on an outer peripheral rim of core 21.
  • the cutting part 22 is made of a composition comprising an abrasive 24, a resin binder, and solid lubricant to reduce friction between the cutting part and the workpiece (or magnet block) during the sawing operation.
  • the lubricant used herein includes boron nitride, and optionally carbon (including graphite and amorphous carbon), molybdenum disulfide, tungsten disulfide, graphite fluoride, and polytetrafluoroethylene (PTFE), which may be used alone or in admixture of two or more.
  • the conventional sawing operation is difficult to reduce the friction between the cutting part side surface and the workpiece by providing a coolant supply for lubrication
  • the inclusion of the lubricant within the cutting part is effective for reducing the friction between the cutting part side surface and the workpiece, thereby preventing the cutting edge from axial runout during the sawing operation. This allows the cutting part to transmit its grinding force only in a radial direction and ensures high-accuracy sawing operation even with the saw blade using a thin core with a low deflective strength.
  • the lubricant should preferably be used in an amount of 1 to 50% by weight of the composition of which the cutting part is made.
  • boron nitride is 1 to 40% by weight
  • carbon including graphite and amorphous carbon
  • molybdenum disulfide is 1 to 40% by weight
  • tungsten disulfide is 5 to 50% by weight
  • graphite fluoride is 5 to 40% by weight
  • PTFE is 5 to 40% by weight.
  • boron nitride is 5 to 30% by weight
  • carbon including graphite and amorphous carbon
  • molybdenum disulfide is 5 to 30% by weight
  • tungsten disulfide is 10 to 40% by weight
  • graphite fluoride is 10 to 30% by weight
  • PTFE is 10 to 30% by weight.
  • the total amount should preferably be in the range of 1 to 50% by weight, more preferably 5 to 40% by weight.
  • the solid lubricant material is in particulate form. Since the cutting part has a width of 0.2 to 2 mm, a particle size in excess of 0.2 mm (200 ⁇ m) is inadequate. Too fine particles have an increased volume, detracting from the strength of the cutting part. According to the invention, the lubricant has a particle size of 1 to 200 ⁇ m, more preferably 10 to 150 ⁇ m.
  • the composition of which the cutting part is made contains abrasive grains, a resin binder, and a structural matrix.
  • Preferred structural matrix materials include SiC e.g. of particle size 1 to 100 ⁇ m, SiO 2 e.g. of particle size 1 to 100 ⁇ m, Al 2 O 3 e.g. of particle size 1 to 100 ⁇ m, WC e.g. of particle size 0.1 to 50 ⁇ m, also Fe, Ni and Cu e.g. of particle size 1 to 200 ⁇ m.
  • Matrix materials may be used alone or in admixture of two or more.
  • the role of the structural matrix material is to increase the strength of the cutting part, prevent the cutting part from deforming in a direction perpendicular to the feed direction of the saw blade during the sawing operation, prevent the cutting edge from axial runout during the sawing operation, allows the saw blade to transmit its grinding force only in a radial direction, and ensures high-accuracy sawing operation even with the saw blade using a thin core with a low deflective strength.
  • the matrix is available in particulate form. Too fine particles have an increased volume, failing to provide the cutting part with strength. If the particle size is large, only one particle is present per width of the cutting part, also leading to a reduced strength.
  • the matrix preferably has a particle size in the above range.
  • the particle size of SiC is 2 to 50 ⁇ m
  • SiO 2 is 2 to 50 ⁇ m
  • Al 2 O 3 is 2 to 50 ⁇ m
  • WC is 1 to 30 ⁇ m
  • Fe, Ni and Cu is 10 to 150 ⁇ m.
  • the matrix material is preferably used at from 20 to 60% by weight, more preferably 25 to 50% by weight of the composition. Outside the range, a smaller amount of the matrix may be less effective whereas a larger amount may detract from the strength of the cutting part.
  • the abrasive grains may be any well-known abrasives, preferably diamond and CBN.
  • the abrasive grains preferably have a particle size of 10 to 200 ⁇ m, more preferably 50 to 200 ⁇ m. A particle size in excess of 200 ⁇ m may exceed the width of the cutting part whereas a smaller particle size may interfere with grinding efficiency, sawing speed, and productivity.
  • the abrasive should preferably be used in an amount of 20 to 60% by weight, more preferably 20 to 40% by weight of the composition. Outside the range, a smaller amount of the abrasive may lead to a lower grinding rate whereas a larger amount may detract from the strength of the cutting part.
  • the binder has a function of binding diamond or CBN, the lubricant and the matrix together to high strength so that a cutting part having a high stiffness despite thinness may be formed.
  • Thermosetting resins are preferred as the binder.
  • phenolic resins, formaldehyde resins and urea resins are more preferred.
  • Phenol formaldehyde resins obtained by condensation of phenol and formaldehyde are most preferred since they have excellent heat resistance and water resistance and can tightly bind the abrasive and matrix.
  • Melamine resins prepared from melamine and formaldehyde are also favorable.
  • the binder should preferably be used in an amount of 10 to 50% by weight of the composition. Outside the range, a smaller amount of the binder may be weak in binding the other components whereas a larger amount of the binder indicates smaller amounts of the other components, leading to shortage of strength, grinding rate and lubrication.
  • the core supporting the cutting part is preferably made of cemented carbide. Any suitable cemented carbide e.g. as described in Patent Document 1 may be used.
  • the workpiece which is intended herein to saw is a rare earth magnet block.
  • the rare earth magnet as the workpiece is not particularly limited. Suitable rare earth magnets include sintered rare earth magnets of R-Fe-B systems wherein R is at least one rare earth element inclusive of yttrium.
  • Suitable sintered rare earth magnets of R-Fe-B systems are those magnets containing, in weight percent, 5 to 40% of R, 50 to 90% of Fe, and 0.2 to 8% of B, and optionally one or more additive elements selected from C, Al, Si, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Sn, Hf, Ta, and W, for the purpose of improving magnetic properties and corrosion resistance.
  • the amounts of additive elements added are conventional, for example, up to 30 wt% of Co, and up to 8 wt% of the other elements. The additive elements, if added in extra amounts, rather adversely affect magnetic properties.
  • Suitable sintered rare earth magnets of R-Fe-B systems may be prepared, for example, by weighing source metal materials, melting, casting into an alloy ingot, finely dividing the alloy into particles with an average particle size of 1 to 20 ⁇ m, i.e., sintered R-Fe-B magnet powder, compacting the powder in a magnetic field, sintering the compact at 1,000 to 1,200°C for 0.5 to 5 hours, and heat treating at 400 to 1,000°C.
  • any well-known procedures may be employed.
  • OD blades were fabricated by providing a doughnut-shaped disk core of cemented carbide (consisting of WC 90 wt%/Co 10 wt%) having an outer diameter 120 mm, inner diameter 40 mm, and thickness 0.3 mm, and heat pressing a composition to an outer peripheral rim of the core to form a resinoid grinding wheel section or cutting part.
  • the composition contained 10 wt% of graphite having a particle size of 5 to 30 ⁇ m as the lubricant, 40 wt% of #800 SiC (GC powder) as the matrix, 25 wt% of a phenol formaldehyde resin as the binder, and 25 wt% of synthetic diamond grains having an average particle size of 150 ⁇ m.
  • OD blades (or sawing abrasive blades).
  • the axial extension of the cutting part from the core was 0.05 mm on each side, that is, the cutting part had a width of 0.4 mm (in the thickness direction of the core).
  • the radial extension or length of the cutting part is 2.5 mm, that is, the blade had an outer diameter of 125 mm.
  • a multiple blade assembly was constructed as shown in FIG. 1 by coaxially mounting 41 OD blades on a shaft at an axial spacing of 2.1 mm, with spacers interposed therebetween.
  • the spacers each had an outer diameter 85 mm, inner diameter 40 mm, and thickness 2.1 mm.
  • the multiple blade assembly was designed so that the magnet block was cut into magnet strips having a thickness of 2.0 mm.
  • the sintered Nd-Fe-B magnet block was sawed.
  • the sintered Nd-Fe-B magnet block had a length 101 mm, width 30 mm and height 17 mm and had been polished on all six surfaces at an accuracy of ⁇ 0.05 mm by a vertical double-disk polishing tool.
  • the magnet block was longitudinally divided into a multiplicity of magnet strips of 2.0 mm thick. Specifically, one magnet block was cut into 40 magnet strips.
  • the sawing operation was carried out while supplying 30 L/min of a grinding fluid or coolant from the feed nozzle, rotating the OD blades at 7,000 rpm (circumferential speed of 46 m/sec), and feeding the multiple blade assembly at a speed of 20 mm/min.
  • a sintered rare earth magnet block was sawed by the same procedure as in Example 1 except that the cutting part composition was changed. In this way, 1000 magnet blocks were sawed, and the sawed state was evaluated. The evaluation results are also shown in Table 1.
  • the composition of the cutting part in Comparative Example 1 contained 45 wt% of #800 SiC (GC powder) as the matrix, 30 wt% of the phenol formaldehyde resin as the binder, and 25 wt% of synthetic diamond grains having an average particle size of 150 ⁇ m.
  • Table 1 Number of strips After sawing of 200 blocks After sawing of 400 blocks After sawing of 600 blocks After sawing of 800 blocks After sawing of 1000 blocks
  • B number of OD blade replacements
  • the sawing method embodying the invention maintained consistent dimensional accuracy for products over a long term despite the reduced blade thickness and is successful in reducing the number of spacer adjustments and the number of OD blade replacements. Then an increase in productivity is attained.
  • OD blades were fabricated by providing a doughnut-shaped disk core of cemented carbide (consisting of WC 90 wt%/Co 10 wt%) having an outer diameter 95 mm, inner diameter 40 mm, and thickness 0.3 mm, and heat pressing a composition shown in Table 2 to an outer peripheral rim of the core to form a cutting part.
  • the axial extension of the cutting part from the core was 0.025 mm on each side, that is, the cutting part had a width of 0.35 mm (in the thickness direction of the core).
  • the radial extension or length of the cutting part is 2.5 mm, that is, the blade had an outer diameter of 100 mm.
  • a multiple blade assembly was constructed as shown in FIG. 1 by coaxially mounting 38 OD blades on a shaft at an axial spacing of 1.05 mm, with spacers interposed therebetween.
  • the spacers each had an outer diameter 70 mm, inner diameter 40 mm, and thickness 1.05 mm.
  • the multiple blade assembly was designed so that the magnet block was cut into magnet strips having a thickness of 1.0 mm.
  • the multiple blade assembly consisting of 38 OD blades and 37 spacers alternately mounted on the shaft was set relative to the sintered Nd-Fe-B magnet block such that the lowermost end of the blades was 2 mm below the bottom surface of the magnet block.
  • the sintered Nd-Fe-B magnet block had a length 50 mm, width 30 mm and height 12 mm and had been polished on all six surfaces at an accuracy of ⁇ 0.05 mm by a vertical double-disk polishing tool.
  • the magnet block was longitudinally divided into a multiplicity of magnet strips of 1.0 mm thick. Specifically, one magnet block was cut into 37 magnet strips.
  • the sawing operation was carried out while supplying 30 L/min of a grinding fluid or coolant from the feed nozzle, rotating the OD blades at 7,000 rpm (circumferential speed of 37 m/sec), and feeding the multiple blade assembly at a speed of 20 mm/min.
  • the saw blades comprising the lubricant ensures high-accuracy sawing operation even when they are as thin as 0.35 mm.
  • the number of cut strips is increased.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Forests & Forestry (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Processing Of Stones Or Stones Resemblance Materials (AREA)
  • Sawing (AREA)

Claims (15)

  1. Lame de scie destinée à être utilisée dans un ensemble à plusieurs lames comprenant une pluralité de lames de scie montées de manière coaxiale sur un arbre rotatif dans des positions axialement espacées, pour être utilisées pour scier un bloc d'aimant de terre rare en plusieurs morceaux en faisant tourner la pluralité de lames de scie,
    la lame de scie comprenant un noyau se présentant sous la forme d'un disque fin et une partie de coupe périphérique sur un rebord périphérique externe du noyau, la partie de coupe étant réalisée avec une composition comprenant un abrasif, un liant résineux, caractérisée en ce que ladite composition comprend en outre du nitrure de bore en tant que lubrifiant pour réduire la friction entre la partie de coupe et le bloc d'aimant pendant l'opération de sciage, et en ce que :
    le nitrure de bore en tant que lubrifiant est sous forme particulaire ayant une taille de particule dans la plage de 1 à 200 µm.
  2. Lame de scie selon la revendication 1, dans laquelle la quantité de nitrure de bore en tant que lubrifiant dans la composition de la partie de coupe représente de 1 à 40% en poids.
  3. Lame de scie selon la revendication 1, dans laquelle la quantité de nitrure de bore en tant que lubrifiant dans la composition de la partie de coupe représente de 5 à 30% en poids.
  4. Lame de scie selon la revendication 1 ou 2, dans laquelle le lubrifiant se présente sous forme particulaire ayant une taille de particule dans la plage de 10 à 150 µm.
  5. Lame de scie selon l'une quelconque des revendications précédentes, dans laquelle la composition de la partie de coupe comprend un matériau de matrice structurel en plus du lubrifiant, de l'abrasif et du liant résineux.
  6. Lame de scie selon la revendication 5, dans laquelle ledit matériau de matrice est choisi parmi SiC, SiO2, Al2O3, WC, Fe, Ni, Cu et leurs mélanges, sous forme particulaire.
  7. Lame de scie selon la revendication 5 ou 6, dans laquelle la composition de la partie de coupe contient de 25 à 50% en poids de matériau de matrice structurel.
  8. Lame de scie selon la revendication 1, dans laquelle ladite composition de la partie de coupe comprend :
    de 10 à 40% en poids de diamant et/ou de CBN en tant qu'abrasif,
    de 20% à 60% en poids de matériau de matrice choisi parmi SiC ayant une taille particulaire de 1 à 100 µm, SiO2 ayant une taille particulaire de 1 à 100 µm, WC ayant une taille particulaire de 0,1 à 50 µm, Fe, Ni et Cu ayant une taille particulaire de 1 à 200 µm, et leurs mélanges,
    de 10 à 50% en poids de résine thermodurcissable en tant que liant, et
    de 1 à 50% en poids de lubrifiant.
  9. Lame de scie selon la revendication 8, dans laquelle le matériau de matrice est ledit SiC ayant une taille particulaire de 1 à 100 µm.
  10. Lame de scie selon la revendication 8 ou 9, dans laquelle la quantité de lubrifiant représente de 1 à 40% en poids.
  11. Lame de scie selon l'une quelconque des revendications précédentes, dans laquelle le noyau est réalisé avec un carbure fritté.
  12. Lame de scie selon l'une quelconque des revendications précédentes, dans laquelle la partie de coupe a une largeur de 0,2 à 2 mm.
  13. Lame de scie selon l'une quelconque des revendications précédentes, dans laquelle le liant résineux est de la résine phénolique, de la résine formaldéhyde ou une résine d'urée.
  14. Procédé pour scier un bloc d'aimant de terre rare en plusieurs morceaux, comprenant les étapes consistant à prévoir un ensemble à plusieurs lames comprenant une pluralité de lames de scie montées de manière coaxiale sur un arbre rotatif dans des positions axialement espacées, chaque lame de scie étant selon l'une quelconque des revendications 1 à 11, et faire tourner la pluralité de lames de scie.
  15. Ensemble à plusieurs lames pour scier des blocs d'aimant de terre rare en plusieurs morceaux, comprenant une pluralité de lames de scie selon l'une quelconque des revendications 1 à 13 montées de manière coaxiale sur un arbre de rotation dans des positions axialement espacées.
EP12194492.0A 2011-11-28 2012-11-27 Lame de scie et procédé pour sciage multiple d'aimant à teneur en terre rare Active EP2596929B1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2011259157 2011-11-28

Publications (2)

Publication Number Publication Date
EP2596929A1 EP2596929A1 (fr) 2013-05-29
EP2596929B1 true EP2596929B1 (fr) 2017-02-22

Family

ID=47257626

Family Applications (1)

Application Number Title Priority Date Filing Date
EP12194492.0A Active EP2596929B1 (fr) 2011-11-28 2012-11-27 Lame de scie et procédé pour sciage multiple d'aimant à teneur en terre rare

Country Status (8)

Country Link
US (1) US20130137343A1 (fr)
EP (1) EP2596929B1 (fr)
JP (1) JP5900298B2 (fr)
KR (1) KR20130059295A (fr)
CN (1) CN103170922A (fr)
MY (1) MY174975A (fr)
SG (1) SG190555A1 (fr)
TW (1) TW201341110A (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USD791205S1 (en) 2015-04-06 2017-07-04 Zenith Cutter, Inc. Serrated male slot knife
USD791206S1 (en) 2015-07-31 2017-07-04 Zenith Cutter, Inc. Serrated male slot knife
JP6896327B2 (ja) * 2017-03-09 2021-06-30 株式会社ディスコ 切削ブレード、マウントフランジ
CN108000611A (zh) * 2017-12-29 2018-05-08 中铁十六局集团第三工程有限公司 一种铁路轨道板伸缩缝环保切割清理锯
USD918280S1 (en) * 2019-02-18 2021-05-04 Cathlyn J Huttner Double cutting die
CN109702255A (zh) * 2019-02-26 2019-05-03 临沂市新天力机械有限公司 一种用于纵横锯边机的铣边装置
JP7298100B2 (ja) * 2019-08-29 2023-06-27 株式会社ノリタケカンパニーリミテド 歯車研削用複層砥石
KR102420875B1 (ko) * 2022-03-25 2022-07-14 최태성 담배 절단용 원형나이프의 제조방법

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004050331A (ja) * 2002-07-18 2004-02-19 Asahi Diamond Industrial Co Ltd 超砥粒ホイール

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6288575A (ja) * 1985-10-14 1987-04-23 Mitsubishi Metal Corp 研削砥石
JPS63283866A (ja) * 1987-02-27 1988-11-21 Toshiba Tungaloy Co Ltd 超砥粒切断・研削砥石
US5313742A (en) * 1991-01-11 1994-05-24 Norton Company Highly rigid composite shaped abrasive cutting wheel
JPH10175172A (ja) * 1996-12-16 1998-06-30 Shin Etsu Chem Co Ltd 希土類磁石切断用マルチダイヤモンド砥石
US6517427B1 (en) * 1998-02-23 2003-02-11 Shin-Etsu Chemical Co., Ltd. Abrasive-bladed multiple cutting wheel assembly
US6595094B1 (en) * 1999-01-29 2003-07-22 Sumitomo Special Metals Co., Ltd. Working cutting apparatus and method for cutting work
US6386948B1 (en) * 1999-06-01 2002-05-14 Sumitomo Special Metals Co., Ltd. Magnet member cutting method and magnet member cutting
US6463920B1 (en) * 1999-11-22 2002-10-15 Sumitomo Special Metals Co., Ltd. Work cutting apparatus and work cutting method
JP4961647B2 (ja) * 2001-09-06 2012-06-27 日立金属株式会社 希土類合金の切断方法および希土類磁石の製造方法
US8568203B2 (en) * 2008-11-05 2013-10-29 Shin-Etsu Chemical Co., Ltd. Method and apparatus for multiple cutoff machining of rare earth magnet block, cutting fluid feed nozzle, and magnet block securing jig
KR101659078B1 (ko) * 2009-09-02 2016-09-22 쓰리엠 이노베이티브 프로퍼티즈 캄파니 절삭 휠용 조성물 및 이를 이용한 절삭 휠
MY157471A (en) * 2010-01-06 2016-06-15 Shinetsu Chemical Co Rare earth magnet holding jig, cutting machine and cutting method

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004050331A (ja) * 2002-07-18 2004-02-19 Asahi Diamond Industrial Co Ltd 超砥粒ホイール

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
WISSLER ET AL: "Graphite and carbon powders for electrochemical applications", JOURNAL OF POWER SOURCES, ELSEVIER SA, CH, vol. 156, no. 2, 1 June 2006 (2006-06-01), pages 142 - 150, XP027937679, ISSN: 0378-7753, [retrieved on 20060601] *

Also Published As

Publication number Publication date
TW201341110A (zh) 2013-10-16
JP2013136143A (ja) 2013-07-11
JP5900298B2 (ja) 2016-04-06
CN103170922A (zh) 2013-06-26
KR20130059295A (ko) 2013-06-05
SG190555A1 (en) 2013-06-28
US20130137343A1 (en) 2013-05-30
EP2596929A1 (fr) 2013-05-29
MY174975A (en) 2020-05-30

Similar Documents

Publication Publication Date Title
EP2596929B1 (fr) Lame de scie et procédé pour sciage multiple d'aimant à teneur en terre rare
US10391602B2 (en) Method for multiple cutoff machining of rare earth magnet
EP2641695B1 (fr) Procédé et appareil pour la coupe de blocs magnétiques de terres rares au moyen d'un ensemble à lames multiples
CN1143754C (zh) 带磨料刀片的多刀切割轮组件
JP2868180B2 (ja) 希土類磁石切断用ダイヤモンド砥石外周刃とそれを用いた希土類磁石の切断方法
CN108247504B (zh) 用于多重切割加工稀土烧结磁体的方法
JPH10175172A (ja) 希土類磁石切断用マルチダイヤモンド砥石
CN108247538B (zh) 稀土烧结磁体的固定夹具
JPH10175171A (ja) 希土類磁石切断用マルチダイヤモンド砥石
KR100542088B1 (ko) 연마재-블레이드다중절삭휠조립품
JP2002137168A (ja) 超砥粒工具
JP2002160166A (ja) 超砥粒工具
JP2003251566A (ja) サーメットを基板とする超砥粒切断ホイ−ル
JP2007253326A (ja) マルチダイヤモンド砥石を使用した希土類磁石のマルチ切断方法
JP2001009730A (ja) 超砥粒工具

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

17P Request for examination filed

Effective date: 20131118

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

17Q First examination report despatched

Effective date: 20151112

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTG Intention to grant announced

Effective date: 20160901

GRAJ Information related to disapproval of communication of intention to grant by the applicant or resumption of examination proceedings by the epo deleted

Free format text: ORIGINAL CODE: EPIDOSDIGR1

GRAR Information related to intention to grant a patent recorded

Free format text: ORIGINAL CODE: EPIDOSNIGR71

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

INTC Intention to grant announced (deleted)
RBV Designated contracting states (corrected)

Designated state(s): DE FR GB

INTG Intention to grant announced

Effective date: 20170112

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602012028886

Country of ref document: DE

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602012028886

Country of ref document: DE

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20171123

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20171122

Year of fee payment: 6

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20180731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171130

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20181127

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20181127

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20230929

Year of fee payment: 12