摘要 |
PURPOSE:To provide a pressure control valve made lightweight by using aluminum and allowing a steel sleeve to be press-fitted into an aluminum spool by shrinkage fitting or cooling fitting and a steel sheet to be press-fitted into the steel sleeve under normal temperature. CONSTITUTION:An insert hole 19a is formed at the pressure chamber 5 side end part of a spool 19 made of aluminum, and a sleeve 20, a cylinder body made of steel, is press-fitted into this insert hole 19a by shrinkage fitting or cooling fitting. The relief pressure of a relief valve is set by press-fitting a steel sheet member 23 into the steel sleeve 20 under normal temperature. |