Jtekt Corporation

Toyoda Koki Kabushiki Kaisha

Toyoda Van Moppes Ltd.

Toyoda Van Moppes Kabushiki Kaisha

Shinji Soma

Tomoyasu Imai

Masato Kitajima

Tomohiro Inagaki

Kunihiko Unno

Naoto Ono

Hiroshi Morita

Hajime Fukami

Tomoyuki Kasuga

Akimitsu Kamiya

Takayuki Moroto

Tomokazu Yamashita

Yasuji Kunihiro

Yasuhisa Sekiya

Naoki Ito

Hiroshi Takehara

Noboru Hiraiwa

Toshiyuki Saito

Kazuhiko Sugita

Koji Nishi

Yasuo Niino

Masahiro Ido

Ryohei Mukai

Kazuhisa Sugiyama

Ryo Ito

Mamoru Katsuta

Toshihiro Tsutsui

Toshiki Sakai

Takuma Kono

Satoshi Okubo

Sadao Sakakibara

Masahiro Yoshida

Takanori Ninomiya

Toshiaki Sakurai

Hitoshi Akahane

Koji Morita

Akira Suzuki

Hiroshi Imaike

A method of manufacturing a grinding wheel, and a grinding wheel. After a first overcoat layer is formed on each of CBN abrasive grains, a second overcoat layer that is plastically deformed under a pressure lower than a pressure under which the first overcoat layer is deformed, is formed on the outer side of the first overcoat layer to manufacture coated abrasive grains. The coated abrasive grains are subjected to pressure-molding to be formed into a prescribed shape under a pressure that is equal to or higher than a pressure under which the second overcoat layer is plastically deformed. The second overcoat layers are deformed and flow to form a molded material having a structure in which the first overcoat layers contact each other, and the flowing second overcoat layers are moved into clearances between the coated abrasive grains. By sintering this, CBN abrasive grains are dispersed at a prescribed distance that is determined by the degree of outer radius of each first overcoat layer, and vacancies are arranged therebetween at a prescribed density.

Grinding wheel manufacturing method and grinding wheel

A grinding machine includes: a grinding wheel of which movement in an X direction and a Z direction is controlled and that grinds a workpiece; and a truing unit that is installed at a predetermined position and that trues a machining surface of the grinding wheel. The truing unit includes: a movable table that is installed to be movable in the X direction relative to a support member; a truer that is rotatably installed in the movable table and that trues the machining surface of the grinding wheel; and an X-direction pressing mechanism that presses the truer in the X direction along with the movable table.

Grinding machine

A CBN grinding particle included in a CBN grinding wheel has a single crystal CBN grinding particle having a tetrahedron construction and a multi crystal CBN grinding particle. The single crystal CBN grinding particle is blended with a ratio of equal to or more than 50% to a total summed volume of the single and multi CBN grinding particles. A CBN grinding wheel having the CBN grinding particle is especially suitable for rough grinding.

Cubic boron nitride grinding wheel

A rotary dresser is provided with a roll having an outer circumferential surface which includes an arc portion or inclined portion differing in diameter in dependence on the axial position thereof, and a plurality of diamond abrasive grains embedded on the outer circumferential surface of the roll. The number of the diamond abrasive grains in the circumferential direction is fixed even at any axial position on the outer circumferential surface of the roll.

Rotary dresser

A cutting tip including a cutting edge portion made of a high-hardness material to take a thin-plate shape; and a support portion made of a material which is more worn in contact with a workpiece than the cutting edge portion not to exert a machining action on the workpiece even in contact with the workpiece, and securing and supporting the cutting edge portion on a reverse side of a rake face of the cutting edge portion. Thus, the width of flank wear is prevented from increasing and chipping of the cutting edge is prevented, so that the life of the cutting tip can be extended.

Cutting tip, method of forming cutting tip, and method of manufacturing cutting tip

A grinding wheel is manufactured such that (a) any one of particles for an abrasive grain layer and particles for a substrate layer are put into the press-mold die, and other particles are put onto the particles in the press-mold die, and then the substrate layer and the abrasive grain layer are integrally press-molded to form a non-baked grinding chip with an arcuate shape; (b) depressions are formed on the abrasive grain layer of the non-baked grinding chip; (c) the grinding chip on which the depressions are formed is baked; and (d) the plurality of baked-grinding chips are adhered to a core of the grinding wheel.

Method for manufacturing grinding wheel having depressions on grinding surface thereof

In a manufacturing method for a grinding wheel in which a plurality of wheel chips each composed of an abrasive grain layer containing superabrasive grains and a foundation layer are adhered to a core attached to a wheel spindle carried by a wheel head of a grinding machine to be drivingly rotatable about a rotational axis and in which a grinding surface formed on the abrasive grain layers grinds a workpiece, drivingly rotatably supported by a workpiece support device of the grinding machine, in contact at a grinding point, the method forms green wheel chips each having opposite ends in a wheel circumferential direction inclined relative to the wheel circumferential direction, bakes the green wheel chips to form baked wheel chips, and adheres the plurality of baked wheel chips to the core so that an oblique groove is formed between adjoining abrasive grain layers.

Obliquely grooved grinding wheel and method for manufacturing the same

In a vitrified bonded grinding wheel that is formed so that superabrasives formed of cubic boron nitride (CBN) grains or diamond grains are bonded and held with a vitrified binder, the vitrified binder is formed of oxide particles and amorphous glass, and the vitrified binder has no open pore that is in fluid communication with outside air.

Vitrified bonded grindstone

A plurality of segmented chips are reinforced by applying an adhesive to the circumferentially opposite end portions thereof, and the adjoining segmented chips adjoining in the circumferential direction are adhered to the circumferential surface of a disc-like core with the adhesives at the circumferentially opposite end portions being not jointed with each other. Thus, the segmented chips can be prevented from being loaded with an unnatural force even when the disc-like core with the segmented chips adhered thereto expands and contracts radially due to thermal expansion and thermal contract. Thereby, expansion and contraction of the disc-like core do not impose a compression stress or the like on adhesives situated between adjoining segmented chips.

Segmented grinding wheel and manufacturing method therefor

In a wheel spindle device wherein a plurality of grinding wheels are attached in a juxtaposed relation to a wheel spindle rotatably carried on a wheel head of a grinding machine, a reference position for specifying a position in the circumferential direction of the grinding wheel is provided on a core member of each of the grinding wheels, and a plurality of inclined grooves at predetermined angular intervals are formed on a grinding surface of each grinding wheel to be inclined relative to the circumferential direction of each grinding wheel. In order that the fluctuations in the dynamic pressure and the grinding resistance between respective grinding wheels and workpiece portions ground therewith do not grow as a combined or synergy effect, the inclined grooves on each grinding wheel are shifted in angular phase from those on another grinding wheel, so that grinding efficiency and accuracy can be enhanced.

Wheel spindle device for grinding machine

In a grinding wheel in which abrasive tips for rough grinding and abrasive tips for finish grinding are alternately bonded to a periphery of a disk type base rotating about a rotation axis, each abrasive tip includes the abrasive layer formed by bonding abrasive grains and a lower layer overlaid and integrally for led with the abrasive layer. The abrasive tip is attached to the periphery of the base at the lower layer. A Young's modulus of the lower layer of the abrasive tip for finish grinding relative to a load acting on the grinding surface of the abrasive tip in an inward direction of the grinding wheel is less than that of the abrasive tip for rough grinding. Thereby, the surface of a workpiece can be both rough-ground and finish-ground with superhigh-precision surface roughness with using one grinding wheel.

Grinding wheel

An abrasive grainincludes a crystal defect CD in its crystal structure CS. The crystal defect CD is formed by a laser irradiation.

Abrasive grain and grindstone

A grinding method of a rotating workpiece W having a cylindrical partand a pair of end facesat both sides of the cylindrical partuses a grinding wheelwhose grinding stone is narrower than a finishing width Sbetween the end faces. In a first grinding step, the grinding wheelis relatively moved to the cylindrical partin a direction crossing the rotational axis of the workpiece W and is shuttled along the rotational axis of the workpiece W at least one time between the finishing width Sof the end facesuntil the grinding wheelreaches the cylindrical part. And in a second grinding step, the grinding wheelis moved from one of the end facesto the opposite end faceon the cylindrical part, so as to finish the end facesto a predetermined width S

Grinding method and grinding machine

First and second end surface truing sections are formed by protruding cylindrical first and second base bodies from opposite end surfaces of a disc-like base of an opposite end surface truing tool in the axial direction thereof and by providing on the external surface of the first base body and the internal surface of the second base body first and second abrasive grain layers in which numerous diamond abrasive grains are adhered with bond material. The rotational axis of the opposite end surface truing tool is inclined relative to the rotational axis of the grinding wheel within almost the same plane at a predetermined inclination angle. By moving the opposite end surface truing tool toward the rotational axis of the grinding wheel, the first and second abrasive grain layers respectively true the grinding surfaces at the opposite ends of the grinding wheel under almost the same condition to sharp grinding surfaces having moderate ruggedness, as they go ahead of the first and second base bodies to be backed up thereby. Consequently, it can be realized to true the grinding surfaces at the opposite ends of the grinding wheel under almost the same condition to the sharp grinding surfaces having the moderate ruggedness.

Double end face truing device, double end face truing tool, and double end face truing method

A grinding machine rotatably carrying a finish grinding wheel and a super-finish grinding wheel respectively on first and second wheel heads practices a method of grinding workpiece surfaces to super-finish surfaces with micro oil pockets. A surface of a workpiece rotatably carried on the machine is first ground with the finish grinding wheel to a predetermined diameter under the control of a sizing device. The workpiece surface is then ground with the super-finish grinding wheel to a target diameter under the control of a sizing device. The super-finish grinding is performed to the extent that peaks of a section curve representing the roughness of the workpiece surface attained by the finish grinding are removed but bottoms of the surface curve are left to a depth when the target diameter is reached, so that the bottoms so left of the roughness constitute the micro oil pockets.

Growing community of inventors

Handa, Japan

Shinji Soma