Grinding stone, manufacturing method of grinding stone, and manufacturing apparatus of grinding stone

A grinding stone comprising:

• a base member;
• and
• abrasive grains, wherein each of the abrasive grains is attached to the base member, each of the abrasive grains has a polyhedral shape in which mutually opposed surfaces are parallel to each other, and face-to-face distances between the mutually opposed surfaces are different from each other depending on the surfaces in each of the abrasive grains,
• wherein, in each of the abrasive grains, a minimum distance of said distances is a value within a predetermined range, and
• wherein the abrasive grains are arranged so that a projecting height of each of the abrasive grains from the base member corresponds to said minimum distance.

A grinding stone comprising:

• a base member;
• and
• abrasive grains, wherein each of the abrasive grains is attached to the base member and has a truncated octahedron shape including hexagonal surfaces and quadrangle surfaces in which mutually opposed surfaces are parallel to each other, and face-to-face distances between the mutually opposed surfaces are different from each other depending on the surfaces in each of the abrasive grains,
• wherein, in each of the abrasive grains, a minimum distance of said distances is a value within a predetermined range, and
• wherein one of said hexagonal surfaces is attached to the base member.

A grinding stone comprising:

• a base member;
• and
• abrasive grains, wherein each of the abrasive grains is attached to the base member, each of the abrasive grains has a polyhedral shape in which mutually opposed surfaces are parallel to each other, and face-to-face distances between the mutually opposed surfaces are different from each other depending on the surfaces in each of the abrasive grains,
• wherein the abrasive grains are arranged on the base member in arbitrary manners from abrasive grains having a minimum projecting heights from the base member to abrasive grains having a maximum projecting height.

A manufacturing method of a grinding stone which is manufactured by attaching abrasive grains respectively having polyhedral shapes in which mutually opposed surfaces are parallel to each other to a base member, the method comprising:

• a classifying step of classifying the abrasive grains based on sizes of the abrasive grains defined by face-to-face distances between the mutually opposed surfaces;
• and
• an attaching step of attaching the abrasive grains classified in the classifying step to the base member,
• wherein the attaching step includes:
• a placement step of placing the abrasive grains classified in the classifying step onto an upper surface of the base member using a template disposed above the base member;
• a vibrating step of applying a vibration to the placed abrasive grains and making broader surfaces of the respective abrasive grains to come in contact with the base member;
• and
• an electrolytic deposition step of electrolytic depositing the abrasive grains to which the vibration is applied.

A manufacturing apparatus of a grinding stone which is manufactured by attaching abrasive grains respectively having polyhedral shapes in which mutually opposed surfaces are parallel to each other to a base member, the apparatus comprising:

• an abrasive grains classifying apparatus adapted to classify the abrasive grains based on sizes of the abrasive grains defined by face-to-face distances between the mutually opposed surfaces;
• and
• an attaching apparatus adapted to attach the abrasive grains classified by the abrasive grains classifying apparatus to the base member,
• wherein the attaching apparatus includes:
• a template which is disposed above the base member to be movable with respect to the base member and formed with a guide hole through which the classified abrasive grains pass;
• a vibration generator connected to the template or the base member and adapted to apply a vibration to the abrasive grains passing through the template;
• and
• an electrolytic deposition bath adapted to electrolytic deposit the abrasive grains passing through the template.