Clamp mechanism of throwaway tip

A clamp mechanism for a milling tool, the clamp mechanism comprising:

• a clamp member having a back surface and a head portion;
• a tool body having a disk shape, the tool body being centered on an axis line of rotation, the tool body comprising:
• an outer circumferential surface;
• and
• a lower surface;
• a tip pocket formed on an outer circumference of the milling tool, the tip pocket having a concave shape;
• a tip fitting seat formed in a wall of the tip pocket, the tip fitting seat being directed towards the direction of rotation of the milling tool;
• a tip body having a substantially square shape, the tip body comprising a plurality of cutting edges formed at a corner portion of the tip body;
• a fitting hole formed through the tip body of the tool body;
• a plurality of contact portions formed in the opening of the fitting hole, each of the plurality of contact portions forming a crescent shape as seen in the direction along a center line,
• wherein a part of the back surface of the head portion of the clamp member contacts a respective one of the plurality of contact portions which is located on a side opposite to a respective cutting edge to clamp the tip body.

A clamp mechanism of a throwaway tip for pressing a throwaway tip, the clamp mechanism comprising:

• a plurality of fitting holes formed in a tip body of a tool holder, each of the plurality of fitting holes having respective center lines parallel to each other;
• a plurality of contact portions of the tip body formed in an opening of the fitting hole;
• and
• a plurality of clamp members provided in the tool body, each of the plurality of clamp members corresponding to a respective fitting hole, and each of the plurality of clamp members comprising:
• a shaft portion inserted into the fitting hole;
• a head portion which passes through the fitting hole, the head portion having an outer diameter equal to or greater than that of the shaft portion and clamping the throwaway tip to the tip fitting seat by allowing the clamp member to advance toward the tip fitting seat in a central axis direction of the shaft portion;
• and
• a section of a back surface of the head portion, the section being perpendicular to the central axis direction and having a circle shape centered at the central axis line;
• wherein a part of the back surface of a respective head portion comes into contact with the respective contact portion formed in an opening of the fitting hole when the respective clamp member is allowed to advance.