Nippon Piston Ring Co., Ltd.

Yoshiaki Fujita

Satoshi Kawai

Takashi Kawaguchi

Shunsuke Takeguchi

Genkichi Umeha

Atsushi Shimura

Tatsumi Yunokawa

An assembled cam shaft including a steel cam shaft member, a journal member made of sintered material and a cam lobe. The sintered material consisting essentially of 0.5 to 4.0% by weight of carbon, 0.1 to 0.8% by weight of phosphorus, 5 to 50% by weight of copper, 1% by weight or less of manganese, 2% by weight or less of silicon, and the balance being iron and impurities.

Assembled cam shaft

A method and device for the examination of a joint between a hollow steel shaft and a piece joined to the steel hollow shaft of a composite camshaft using ultrasonic examination. In the ultrasonic examination, the composite camshaft is put into a liquid and a probe of an ultrasonic search unit is inserted inside of the hollow steel shaft. The ultraonic examination of the joint is performed from inside of the hollow steel shaft. According to the ultrasonic examination, any kind of joint of the composite camshaft is possible, because a distance from an inside surface of the hollow steel shaft to the joint is constant. In addition, since the probe does not contact the inside surface of the hollow steel shaft, the probe is not consumed due to abrasion.

Ultrasonic joint inspection device and method

A method and device for the examination of a joint between a hollow steel shaft and a piece joined to the steel hollow shaft of a composite camshaft using ultrasonic examination. In the ultrasonic examination, the composite camshaft is put into a liquid and a probe of an ultrasonic search unit is inserted inside of the hollow steel shaft. The ultrasonic examination of the joint is performed from inside of the hollow steel shaft. According to the ultrasonic examination, any kind of joint of the composite camshaft is possible, because a distance from an inside surface of the hollow steel shaft to the joint is constant. In addition, since the probe does not contact the inside surface of the hollow steel shaft, the probe is not consumed due to abrasion.

Method and device for examination of a joint of a ultrasonic joint

A hollow cam shaft for use in an internal combustion engine is disclosed. The cam shaft includes a steel pipe, a journal portion and a cam portion. The journal portion is provided at a part of the outer peripheral surface of the steel pipe and having an outer diameter smaller than that of the steel pipe. A cam lobe is assembled on the other portion of the outer peripheral surface of the steel pipe. The journal portion is formed by cutting the part of the outer peripheral surface of the steel pipe by a uniform axial length and radial depth.

Hollow cam shaft

A wear resistant sintered alloy consisting essentially of from 2.0% to 3.5% by weight of C, from 0.3% to 0.8% by weight of P, from 0.5% to 3.0% by weight of Mn and remainder Fe. The alloy is sintered in the liquid-phase.

Sintered alloy having improved wear resistance property

The method of manufacturing a lightweight, low cost hollow cam shaft includes the steps of forming an integral journal portion in a hollow pipe member by inwardly deforming a portion of the pipe member, such as by coining or spinning, the outer surface of the deformed portion being the bearing surface. Annular grooves formed immediately adjacent the inwardly deformed portion allow residue from an optional finish-grinding operation to escape. Cam members having fitting holes are fixedly mounted on undeformed pipe portions, or on outwardly deformed pipe portions.

Growing community of inventors

Omiya, Japan

Yoshiaki Fujita