Mitsubishi Materials Corporation

Hitachi Metals, Ltd.

Nippon Institute of Technology

Hideo Takizawa

Yuji Ishiwari

Jun Ohsone

Hiroaki Kikuchi

Masayuki Watanabe

Shimpei Hirose

Various implementations include a ring material used for producing a ring molded article. The ring molded article has two convex portions which respectively protrude on opposite sides of the ring molded article in a direction of a center axis thereof and extend in a direction of a circumference of the ring molded article. A straight line passing through centers of gravity of first and second side regions is inclined by an angle relative to the center axis of the ring material, the first and second side regions are obtained by virtually dividing a one half section of the ring material based on a middle of a maximum height of the ring material in the direction of the center axis of the ring material, and a range of the angle is 7 degrees to 40 degrees.

Ring molded article manufacturing method and ring material

Various implementations include a method of manufacturing a ring molded article. The ring molded article has two convex portions which respectively protrude on both sides of the ring molded article in a direction of a center axis thereof and extend in a direction of a circumference of the ring molded article. The ring material is placed inside two molds on which concave portions respectively corresponding to the convex portions are formed. The ring material is supported by a region on an outer peripheral side from an outer peripheral side corner in the concave portion of one of the two molds and a region on an inner peripheral side from an inner peripheral side corner in the concave portion of another of the two molds. The ring material is then forged so as to be pressed by the two molds in a direction of a center axis of the ring material.

A method of manufacturing an annular material includes: a forging process of making a discoid forged material by forging an alloy material; and a ring rolling process of making an annular material by performing ring rolling on an annular intermediate made by forming a through-hole in the forged material. In the forging process, hot forging which achieves an absolute value &#x3b5;&#x3b8;of a strain in a circumferential direction of the forged material that is greater than or equal to 0.3, an absolute value &#x3b5;h of a strain in a height direction of the forged material that is greater than or equal to 0.3, and a ratio &#x3b5;h/&#x3b5;&#x3b8;between the absolute values of the strains that is in a range of 0.4 to 2.5 is performed at least two or more times.

Method of manufacturing annular molding

This ring rolling mill includes a main roll and a mandrel that are brought close to or separated from each other, and roll a peripheral portion of a ring-shaped body in a radial direction of the ring-shaped body while the ring-shaped body is rotated along its peripheral direction in a state where the peripheral portion of the ring-shaped body is pinched in the radial direction between an outer peripheral surface of the main roll, and an outer peripheral surface of the mandrel. This ring rolling mill further includes a mechanism which inclines and supports the mandrel with respect to the rotation axis of the main roll such that the gap between the outer peripheral surface of the mandrel and the outer peripheral surface of the main roll differs on one side and on the other side as seen in a direction along the rotation axis of the main roll.

Ring rolling mill and ring rolling method

This ring rolling mill includes a main roll and a mandrel provided so as to be capable of being brought close to or separated from each other, and rolling a peripheral portion of a ring-shaped body in a radial direction of the ring-shaped body while the ring-shaped body is rotated along its peripheral direction in a state where the peripheral portion of the ring-shaped body is pinched in the radial direction between an outer peripheral surface of the main roll which is rotationally driven, and an outer peripheral surface of the mandrel which is rotatable. This ring rolling mill further includes a mandrel inclining/supporting mechanism which inclines and supports the mandrel with respect to the axis of rotation of the main roll such that the gap between the outer peripheral surface of the mandrel and the outer peripheral surface of the main roll differs on one side and on the other side as seen in a direction along the axis of rotation of the main roll.

Elongation in the circumferential direction of a rotary formed body is produced only within a model zone, and the approximate toric plate shape is maintained as the overall shape of the body, and the rotation axis of the body is positioned on a straight line connecting axes of rotation of a main roll and a mandrel roll. Moreover, the velocity of each nodal point and on imaginary cutting planes, that is a velocity boundary condition is expressed by a linear combination of coefficients comprising a radius of the imaginary cutting planes, and angles made by the imaginary cutting planes, with respect to three variables comprising an increasing rate of the radius of the body, an angular velocity for rotation about the rotation axis of the body, and a correction value for the traverse velocity of the rotation axis of the body.

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Saitama, Japan

Hideo Takizawa