Sumitomo Electric Hardmetal Corp.

Sumitomo Electric Industries, Limited

Mori Seiki Co., Ltd.

Dmg Mori Seiki Co., Ltd.

Kazuo Maeda

Shigenori Emoto

Morihiro Hideta

Jun Maeda

Yasuhiro Inamasu

Hisao Oka

Hideo Mori

Kouji Tominaga

Tatsuya Shino

Atuhiko Maeta

Syoji Okui

A ball end mill in which a ball end cutting edge () has a convex shape in a tool rotation direction with respect to a line connecting a rotation center (O) and a radially outer end () of the ball end cutting edge (), in a front view of the tool. In the ball end mill, a rake angle (&#x3b3;) of each portion of the ball end cutting edge () is set in a range from &#x2212;10&#xb0; to 0&#xb0;, and the negative value of the rake angle (&#x3b3;) is increased from a tip of the ball end cutting edge () and a radially outer end () of the ball end cutting edge () toward a middle point in the radial direction, and is maximized at approximately the middle point in the radial direction.

Ball end mill

A tool has a shank and a cutting blade mounted on the shank. The tool also includes an internal fluid passage for drawing in, together with air, chips produced when the cutting blade machines a workpiece. The internal fluid passage comprises a through hole made in the shank, at least one main inlet hole for drawing in the chips together with the air, the main inlet hole being made in the cutting blade and being in fluid communication with the through hole, and at least one sub-inlet hole for drawing in at least the air, the sub-inlet hole being made in the shank and being in fluid communication with the through hole. The chips can efficiently be discharged from the tool without being deposited in the internal fluid passage, by the air which flows at a suitable speed through the internal fluid passage and draws the chips, regardless of the diameter of the tool.

Tool with internal fluid passage

An end mill includes first cutting edges which spiral in a direction defining a positive helix angle and second cutting edges which spiral in a direction defining a negative helix angle, the first cutting edges and the second cutting edges being disposed at positions shifted in a circumferential direction. The first cutting edges and the second cutting edges are each configured to be continuous over an effective cutting edge length. At an axially forward end of the end mill, a first phase angle between one of the first cutting edges and its adjacent second cutting edge located adjacent to the first cutting edges in an opposite direction to a tool rotation direction is set to be different from a second phase angle between the second cutting edge and its adjacent first cutting edge located adjacent to the second cutting edges in the opposite direction to the tool rotation direction.

End mill

A cubic boron nitride radius end mill includes a sintered cubic boron nitride compact bonded to an end of a main body, and a cutting edge provided on the sintered cubic boron nitride compact. The wedge angle &#x3b8;t of the cutting edge is constant over the entire region of the cutting edge. A negative rake face is disposed on a face so as to extend over the entire region of the cutting edge, and the rake angle &#x3b8;n of the negative rake face satisfies the relationship &#x2212;30&#xb0;&#x2266;&#x3b8;n&#x2266;&#x2212;50&#xb0;. A joint cutting edge is disposed between an end cutting edge and a radius cutting edge in the cutting edge, the joint cutting edge having a concave angle &#x3b3;0 which is smaller than the concave angle &#x3b3;1 of the end cutting edge and which satisfies the relationship 0.5&#xb0;&#x2266;&#x3b3;0&#x2266;2&#xb0;.

Cubic boron nitride radius end mill

A throw-away insert includes: an upper surface; a bottom surface; two side surfaces formed with upper side surfaces and lower side surfaces; two end surfaces; four nose sections formed at the corners of the upper surface; a main cutting section formed from a ridge line positioned at the intersection between the upper side surface and the upper surface; a secondary cutting section formed from a linear ridge line positioned at the intersection between the end surface and the upper surface; and an axial support surface formed from a section of the end surface. The upper side surface is projected outward more than the lower side surface.

Throw-away insert and milling cutter using a throw-away insert

A throw-away insert includes: an upper and bottom surface; two side surfaces; two end surfaces; a main cutting section formed from a ridge line positioned at the intersection between the side surfaces and the upper surface; a secondary cutting section formed from a ridge line positioned at the intersection between the end surfaces and the upper surface; an axial support surface supported by an insert pocket of a cutter body; and noses formed at the corners of the upper surface. The corner angles of the noses when seen from above are essentially right angles. The axial support surface is formed as a section of the end surface. The secondary cutting section is parallel to the ridge line at the upper end of the axial support surface and the bottom surface. The upper end of the axial support surface is positioned so that it is projected more in the direction of the longitudinal axis of the main cutting section than the ridge line of the upper end.

Throw-away insert and milling cutter using throw-away insert

A throwaway insert for a ball end mill having an ideal cutting edge shape corresponding to the cutting speeds and loads at different portions of the cutting edges, high in strength and capable of discharging chips smoothly. As viewed in a direction perpendicular to the line connecting noses, each cutting edge forms a convex curve with its nose portion at the lowest level. As viewed in a direction perpendicular to the abovesaid direction, rake faces form symmetrical, downwardly sloping convex accurate surfaces or straight surfaces having a positive rake angle of 5-25.degree.. The wedge angle at the cutting edges is set at 85-65.degree.. Thus, the rake angle will be negative at the noses and positive at other portions. Further, the rake angle increases toward the side where the cutting speed is higher. The thickness of the insert increases toward the side where the load is greater. Since this insert is a modification of a negative insert, i.e. an insert of the type having a side perpendicular to its bottom, it has enough strength. Chips can be discharged smoothly too.

Growing community of inventors

Itami, Japan

Kazuo Maeda