A variable nozzle unit includes: a connection pin which includes a shaft; a support ring which is provided with a first through-hole; and a nozzle ring which is provided with a second through-hole, in which the shaft is inserted through the first through-hole and the second through-hole, one end of the shaft is provided with a flange portion having a diameter larger than that of the second through-hole and the other end of the shaft is provided with a head portion having a diameter larger than that of the first through-hole, the flange portion is in contact with the nozzle ring, and an elastic member that urges the support ring toward the nozzle ring is disposed between the head portion and the support ring.

A variable nozzle unit includes: a connection pin which includes a shaft; a support ring which is provided with a first through-hole; and a nozzle ring which is provided with a second through-hole, in which the shaft is inserted through the first through-hole and the second through-hole, one end of the shaft is provided with a flange portion having a diameter larger than that of the second through-hole and the other end of the shaft is provided with a head portion having a diameter larger than that of the first through-hole, the flange portion is in contact with the nozzle ring, and an elastic member that urges the support ring toward the nozzle ring is disposed between the head portion and the support ring.

In a method for thickening a plastically deformable hollow body wall of a hollow body, with effective radial support of the unthickened hollow body wall on an outer supporting face of an outer mold and with effective radial support of the hollow body wall on an inner supporting face of an inner supporting body, the hollow body is acted on by a compressive force by two application members at application points by moving the application members towards one another in the axial direction with a compressing movement. The application points on the hollow body are distanced from one another in the axial direction. An expansion space of the outer mold is arranged between the application points. Due to the compressing movement of the application members, material of the hollow body wall between the application points is plasticised in the region of the expansion space of the outer mold, and plasticised material of the hollow body wall flows into the expansion space of the outer mold, thus thickening the hollow body wall.

In a method for thickening a plastically deformable hollow body wall of a hollow body, with effective radial support of the unthickened hollow body wall on an outer supporting face of an outer mold and with effective radial support of the hollow body wall on an inner supporting face of an inner supporting body, the hollow body is acted on by a compressive force by two application members at application points by moving the application members towards one another in the axial direction with a compressing movement. The application points on the hollow body are distanced from one another in the axial direction. An expansion space of the outer mold is arranged between the application points. Due to the compressing movement of the application members, material of the hollow body wall between the application points is plasticised in the region of the expansion space of the outer mold, and plasticised material of the hollow body wall flows into the expansion space of the outer mold, thus thickening the hollow body wall.

The present disclosure relates to a steel forging process, in particular a hot steel forging process in horizontal press of a metal tube, preferably a cylindrical steel tube.

The present disclosure relates to a steel forging process, in particular a hot steel forging process in horizontal press of a metal tube, preferably a cylindrical steel tube.

A method of manufacturing an engine valve intermediate product with a boss portion formed in integral fashion at an outer circumferential surface at an intermediate location on a stem forming portion. The manufacturing method may comprise a stem retaining operation in which an intermediate location of the stem forming portion is retained by a plurality of intermediate jigs removably installable radially with respect to a center of the stem forming portion, and a base end portion is retained by a base end jig. The manufacturing method may further comprise a stem enlarging operation in which compressive forces are applied from both ends of the intermediate product and the boss portion is formed as the intermediate product is made to rotate and alternating loads that cause tensile forces and compressive forces to act in repeated and alternating fashion at the outer circumferential surface of the stem forming portion are applied.

The disclosure of the present specification aims to provide a directivity control system for speakers, which is capable of easily controlling directivity of acoustic data to provide desired sound fields with a plurality of speakers, and freely producing sound fields with high accuracy. A plurality of physically connected speaker units are virtually arrayed at respective directivity angles according to control signals that define the directivity angles. Virtual delay time data is calculated for the case where data is outputted with the virtual array, and output is performed according to output data affected by the delay time data, so that desired sound fields can be formed with the speaker units remaining fixed, without the necessity of mechanically rotating the speaker units.

Provided are a hollow drive shaft using an upsetting method and a method of manufacturing the same, in which hot forging and upsetting processes are applied to both ends of a workpiece so that an outer diameter at both ends of the workpiece is greater than an outer diameter of a middle part of the workpiece, thereby reducing a weight of the drive shaft and enabling the drive shaft to transmit higher driving power. According to the present invention, the upsetting process is applied during the hot forging process to manufacture the hollow drive shaft, portions to be substantially processed are limited to portions at both ends of the workpiece, and the number of upsetting processes is limited to a minimum number (2 or the like), such that initial investment costs and manufacturing costs are low because the number of processes is small.

Provided are a hollow drive shaft using an upsetting method and a method of manufacturing the same, in which hot forging and upsetting processes are applied to both ends of a workpiece so that an outer diameter at both ends of the workpiece is greater than an outer diameter of a middle part of the workpiece, thereby reducing a weight of the drive shaft and enabling the drive shaft to transmit higher driving power. According to the present invention, the upsetting process is applied during the hot forging process to manufacture the hollow drive shaft, portions to be substantially processed are limited to portions at both ends of the workpiece, and the number of upsetting processes is limited to a minimum number (2 or the like), such that initial investment costs and manufacturing costs are low because the number of processes is small.