Jtekt Corporation

Toyoda Koki Kabushiki Kaisha

Toyoda Van Moppes Kabushiki Kaisha

Tomoyuki Kasuga

Shinji Soma

Hiroshi Morita

Tomoyasu Imai

Norio Ohta

Ryohei Mukai

Yukio Oda

Takayuki Yoshimi

Atsushi Saito

Ryo Ito

Naoto Ono

Akira Makiuchi

Toshiaki Naya

Takanori Ninomiya

Masao Ikeda

Takafumi Furutate

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 abnormality monitoring method and device for grinding a plurality of works of the same type are proposed which can improve the accuracy of judgment whether an abnormality is generated or not by properly setting a threshold value. According to the method or the device, by setting at least one of upper and lower limit values of a trial grinding load detected at the trial grinding of at least one of the works, an occurrence of grinding abnormality is judged when an actual grinding load detected at the actual grinding of work exceeds at least one of the upper and lower limit values thereof which varies depending on the time elapsed from the start of the actual grinding or a position of work relative to a grinding wheel.

Grinding abnormality monitoring method and grinding abnormality monitoring device

A wheel truing apparatus adapted for use in a cylindrical grinding machine wherein a work head with a work spindle for support of a workpiece and a wheel head with a grinding wheel for grinding the workpiece are mounted on a bed for relative movement in a Z-axis direction parallel with the rotation axis of the work spindle and in an X-axis direction crossing the Z-axis direction, characterized in that the wheel truing apparatus comprises a rotary drive portion mounted on the work head or a member united therewith, and a wheel truing tool supported on the rotary drive portion for rotation therewith, the wheel truing tool being provided at its outer periphery with a truing portion for truing a grinding surface of the wheel brought into contact therewith, wherein the rotary drive portion is placed in a position adjacent to said work head in a tooling area defined by a stroke of the relative movements of said wheel head and said work head in the Z-axis direction and apart from said work spindle radially outward and is arranged in such a manner that the rotation axis line of said truing tool is oriented toward the rotation axis line of said grinding wheel in a condition where said truing portion is retained in contact with the grinding surface of said wheel, whereby the truing portion of said tool is brought into contact with the grinding surface of said wheel by relative movement of said wheel head to said work head for truing the grinding surface.

Truing apparatus of 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 wheel comprising abrasive grains, a bonding material for bonding the abrasive grains, and grain clusters of accumulated filler grains having a size smaller than the abrasive grains. The grinding wheel may be a vitrified grinding wheel, and in this case, chromium oxide having good affinity with the vitrified bonding material may be used as the filler grains.

Grinding wheel

A grinding machine having an angular type grinding wheel and a dressing apparatus therefor. The grinding wheel is formed with first and second grinding surfaces usable for grinding a cylindrical surface and shoulder end surface of a workpiece, respectively, and first and second reference surfaces parallel to the first and second grinding surfaces, respectively. The positions of the first and second reference surfaces and the first and second grinding surfaces are detected with touch bars before each dressing operation so as to obtain a first distance between the first grinding surface and first reference surface, and a second distance between the second grinding surface and second reference surface. After that, a first dressing amount for dressing the first grinding surface and a second dressing amount for dressing the second grinding surface are so determined that the first distance and the second distance would have a predetermined constant relationship after dressing operation. The first grinding surface is then dressed by the first dressing amount, while the second grinding surface is dressed by the second dressing amount.

Method and apparatus for dressing an angular grinding wheel

Growing community of inventors

Nagoya, Japan

Tomoyuki Kasuga