Abstract: In a drive shaft press-fitting device, when a collet chuck (clamp) is moved backward by a linear motion means, the end part of the collet chuck closes by collaboration of a tapered surface of the collet chuck and an engagement part of a sleeve, and thereby the collet chuck holds an external thread part of the drive shaft. When the collet chuck is further moved backward by the linear motion means, the drive shaft is drawn out of the axle hub by the collet chuck, and thereby the drive shaft is pressed into the axle hub. After press-fitting, when the collet chuck is moved forward by the linear motion means, the collet chuck opens to be away from the external thread part of the drive shaft by a biasing means.

Abstract: An automatic assembling apparatus automatically assembles such parts as an engine and a suspension to each work such as a car body conveyed by a conveyor. The system includes a parts truck and a screwing truck. The parts truck can be moved parallel to the conveying path of the conveyor and includes a coupling mechanism for coupling it to the conveyor and an approach truck for approaching the work while carrying the parts. The system further includes a screwing truck which can be moved parallel to the conveying path of the conveyor and includes a coupling mechanism for coupling it to the conveyor and a screwing mechanism for effecting screwing by approaching the work. The parts truck and the screwing truck are coupled to the conveyor and are moved in synchronism with the work. The parts are positioned as the approach truck approaches, and the screwing is effected as the screwing mechanism approaches. The parts are assembled without stop of the work.

Abstract: In a process for producing a surface remelted chilled layer camshaft by using a high density energy irradiation and self-cooling, a cam is rotated around the center axis of the camshaft and a position of a torch for the irradiation (e.g., a TIG arc torch) is controlled so as to form an angle between a tangential line of the cam surface and a horizontal line at a melting position in a lower side of the horizontal line in a direction opposite to the camshaft rotation direction being from 30.degree., preferably 20.degree., to zero degree.

Abstract: A process for producing a camshaft with cams include the steps of forming a surface hardened layer in each of the cams by a remelting chilling treatment using high density energy (e.g., a TIG arc), characterized in that after the remelting chilling treatment, the camshaft is cooled by passing a cooling medium through a through hole formed longitudinally in the camshaft. As a result of the cooling, the neighboring untreated cam has a temperature of up to 250.degree. C. Elongation of the camshaft due to thermal expansion is so small that no melt-down end portion defects appear.