Patent ID: 8118080
Filing Date: 2012-02-21
Classification: B22D,F16H,Y10T

Abstract:
1. A control valve body of an automatic transmission where a channel groove for hydraulic oil for use in a speed change operation of the automatic transmission is formed between partitions, wherein the control valve body is manufactured by a manufacturing method comprising: a magnesium die-casting step of pouring, by means of pressure, melted liquid of magnesium or magnesium alloy into a hollow portion formed using a casting mold, to thereby mold a valve body having the partitions formed thereon, and wherein in the magnesium die-casting step, the channel groove having a width of less than 3 mm is formed due to a convex portion which is formed on the casting mold so as to project into the hollow portion, and a draft angle of the partitions is smaller than two degrees.