Chiaki Tsumuki

Development of Powder-Forged Connecting Rods

In comparison with conventional hot forging process, powder forging process has much advantage such as good dimensional accuracy, minimum scattering of weight, etc. In spite of much advantage, the powder forged parts have not been mass-produced except for relatively simple shape parts because of technical and economic problems such as low productivity. Solving these problems, powder forging process was applied to connecting rods which required fatigue strength and minimum scattering of weight, and which were complex in shape. As a result, for the first time in the world, mass-production of powder forged connecting rods was carried out, and its properties are as follows: (1) Sufficient fatigue strength; (2) Minimum scattering of weight; and (3) Good dimensional accuracy.