PURPOSE: To obtain a locker arm having abrasion resistance and seizure resistance corresponding to the other member by forming a decarburized layer on the whole locker arm, and thereafter, removing the decarburized layer and increasing a carbide, in the part which requires abrasion resistance and seizure resistance.
CONSTITUTION: The part which contacts with a cam 3 slidably and a valve stem 4 of said locker arm 1 which forms a decarburized layer on the whole body is formed by a locker arm material having essential abrasion resistance and seizure resistance of the material, that is, a layer which removes the decarbuirized layer and increases a carbide. On the other hand, the part which contacts with an adjuster 2 slidably is formed to a material state that the decarburized layer is left. Therefore, a coarse material which sets a working allowance of about 1mm being more than 0.6W0.7mm thickness of the decarburized layer, which is investigated in advance is manufactured by a precise casting method on the parts 5, 6 which contact slidably with the cam 3 and the valve stem 4 of the locker arm 1. Thereafter, as for the parts 5 and 6, the working allowance is removed by a machine work, and the locker arm 1 which has essential abrasion resistance and seizure resistance of the inside material and exposes the material surface is manufactured.
HAYASHI YOSHIROU
FUKUDA TOKIHARU
EKINO YOSHIO
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