Mitsubishi Heavy Industries Limited

Fuji Hollow Valve Inc.

Yoshimura Company

Kabushiki Kaisha Kobe Seiko Sho

Mitsubishi Heavy Industries Machine Tool Co., Ltd.

Kenichiro Hirao

Hirokazu Morii

Hyoji Yoshimura

Noritaka Fujimura

Hidenobu Nishio

Katsumi Nakamura

Takashi Ueda

Tsugumaru Yamashita

Mariko Matsuda

Kazuya Sugitani

A manufacturing method for a hollow engine valve comprises: a step of forming, by forging, a solid round bar as a material of a valve main body into a valve main body intermediate member provided with a semifinished product valve head portion corresponding to a valve head portion and a solid stem portion corresponding to a valve stem portion; a step of performing cutting process with respect to the valve main body intermediate member across the solid stem portion and the semifinished product valve head portion for forming a semifinished product hollow hole with a bottom corresponding to a hollow hole; and a step of performing necking process with respect to the valve main body semifinished product for squeezing the semifinished product valve stem portion step by step, to form the valve main body semifinished product into the valve main body.

Hollow engine valve and manufacturing method therefor

The present invention provides a hollow engine valve achieving high durability while suppressing an increase in manufacturing cost, and a manufacturing method therefor. A manufacturing method for a hollow engine valve comprises: a step of forming, by forging, a solid round bar as a material of a valve main body into a valve main body intermediate member provided with a semifinished product valve head portion corresponding to a valve head portion and a solid stem portion corresponding to a valve stem portion; a step of performing cutting process with respect to the valve main body intermediate member across the solid stem portion and the semifinished product valve head portion for forming a semifinished product hollow hole with a bottom corresponding to a hollow hole, thereby forming the valve main body intermediate member into a valve main body semifinished product provided with the semifinished product valve head portion and a semifinished product valve stem portion; and a step of performing necking process with respect to the valve main body semifinished product for squeezing the semifinished product valve stem portion step by step, thereby reducing the diameter of the semifinished product valve stem portion and increasing the length of the stem of the semifinished product valve stem portion, to form the valve main body semifinished product into the valve main body.

The present invention provides a method for producing a hollow engine valve, with which the production process can be simplified and the processing precision can be improved. To this end, the present invention provides a method for producing a hollow engine valve () which is provided with a valve main body () in which a hollow hole () is formed along a valve umbrella part () and a hollow shaft part (), wherein a solid round bar () forming the material of the valve main body () is molded to a semi-finished article () by means of a single hot-forging process, the semi-finished article () is subjected to rotary swaging whereby the semi-finished article () is molded into a semi-finished article (), the semi-finished article () is subjected to necking whereby the semi-finished article () is molded into the valve main body (), and a shaft end sealing member () is joined to the end part of the hollow shaft part () of the valve main body ().

Method for producing a hollow engine valve

A method for manufacturing a hollow engine valve includes a step for performing rotational plastic working on a follow engine valve body semifinished product which is configured from a shaft part and a valve umbrella part forming portion connected to the shaft part. A columnar hole part is formed from the shaft part to an enlarged diameter section of the valve umbrella part forming portion to thereby reduce the diameter of the shaft part. A necking step follows the rotational plastic working step, necking the hollow engine valve body semifinished product to thereby reduce the outer diameter and the inner diameter of the shaft part. A sealing step seals the leading end of the shaft part to obtain the hollow engine valve.

Method for manufacturing hollow engine valve

Provided is a tool tight-contact-state detector for a machine tool which is capable of accurately and stably detecting whether or not a tool or a tool holder having the tool attached thereto is mounted to a main spindle in tight contact therewith. While rotation of a main spindle () is stopped, hydraulic pressure is supplied from a hydraulic pressure supply unit () to a cylinder section () so as to bring a piston member () to into contact with a main spindle head () and the main spindle () against a biasing force from an O-ring (). Air is thereby allowed to be supplied to air ejection holes (), which are formed in a forward end face () of the main spindle (), from the main spindle head () side through the piston member (). Then, a judgment is made as to whether or not an end face () of a tool () and a forward end face () of the main spindle () are in tight contact therewith, on the basis of detection by air pressure detection sensors () regarding pressure variations in the air injected from the air ejection holes ().

Tool tight-contact-state detector for machine tool

Work line module comprises a plurality of machines (-) having a plurality of working functions and non-work facility () such as a conveying machine can cooperate so as to produce a necessary amount even if the necessary amount is varied. A plurality of work machines (-) for mechanically working a workpiece () and non-work facility () for processing the workpiece (). One work machine () is a multifunction furnishing machine having a function of measuring the workpiece () in addition to a function of mechanically working the workpiece (). A conveying machine () having robots (-) for conveying the workpiece () between the work machines (-), and between the work machines (-) and the non-work facility ().

Growing community of inventors

Tokyo, Japan

Kenichiro Hirao