Mitsubishi Heavy Industries Limited

Mitsubishi Heavy Industries Machine Tool Co., Ltd.

Yoshimura Company

Kazutaka Maruyama

Hirokazu Morii

Hyoji Yoshimura

Toshimasa Kikuchi

Takahide Tokawa

This gear cutting machine, which is equipped with a cutter (), a cutter spindle motor () that causes, via a crank mechanism () and a cutter spindle (), the cutter () perform a stroke operation, and a motor control unit () that controls the rotation angle of the cutter spindle motor (), is provided with a relieving spindle motor () that causes the cutter () to move in the direction of a relieving spindle via a link mechanism (four-joint link mechanism ()). The motor control unit () controls the rotation angle of the relieving spindle motor () on the basis of the rotation angle of the cutter spindle motor (). Consequently, a gear cutting machine that accurately controls the relieving operation in accordance with a desired shape, such as crowning and tapering of a gear to be cut can be provided.

Gear-cutting machine

The vertical movement cycle and trajectory inclination angle of a cutter are switched so that when a main spindle is moving downward, a head is moved to position the cutter at a machining location, and the cutter is lowered rectilinearly; that when the main spindle is moving upward, the head is moved to position the cutter at a withdrawal location; that, when an external gear is to be generated by cutting, relieving means for rectilinearly raising the cutter cause the machining location to be positioned on one radial side of the cutter and move the cutter downward parallel to the axis of a workpiece; and that when an internal gear is to be generated by cutting, said relieving means cause the machining location to be positioned on the other radial side of the cutter and move the cutter downward parallel to the axis of the workpiece.

Gear shaping machine

A vibration-reduction mechanism for a gear cutting machine is provided with a vibration-reduction mechanism that includes balancer shafts arranged in parallel to a crank shaft. The balancer shafts rotate synchronously with the crank shaft at the same speed as the speed of the crank shaft. One balancer shaft rotates in the opposite direction to the rotational direction of the crank shaft while the other balancer shaft rotates in the same direction as the rotational direction of the crank shaft. The vibration-reduction mechanism also includes: main balancer weights detachably attached onto the crank shaft; and sub balancer weights detachably attached onto the balancer shafts. The balancer weights are selected on the basis of a stroke width of the main shaft and on the basis of a lead corresponding to the helical angle to be formed in the workpiece W.

Vibration-reduction mechanism for gear cutting machine

Provided is a method for producing an engine valve by subjecting a stem portion having a hollow part to a drawing treatment using a series of dies such that the outer diameter and inner diameter of the stem portion become smaller in steps and the stem portion is thereby molded to the desired size, whereby, after the stem portion has been subjected to the drawing treatment until the inner diameter of the hollow part of the stem portion has reached a specific size, sodium metal in the form of a solid block is introduced to the hollow part of the stem portion, and a protective agent made from solid paraffin or naphthalene is also introduced to the hollow part of the stem portion such as to form a barrier between the sodium metal and the atmosphere, after which the stem portion is further subjected to a cold drawing treatment.

Growing community of inventors

Tokyo, Japan

Kazutaka Maruyama