| 摘要 |
PURPOSE:To improve dimensional accuracy by press fitting an inner sleeve formed on the outer periphery with grooves in a cylindrical outer sleeve, thereafter fixedly soldering both sleeves and cutting axially the core portion thereof to form a spool bore. CONSTITUTION:An inner sleeve 7 is incorporated in the bore of an outer sleeve 6 by press fitting and fixedly soldering. The press fitting is carried out by driving or pushing and soldering is carried out at ends of the inner and outer sleeves 7, 6 or the respective connections of ports a-e. Thus, the core portion 8 of incorporated inner sleeve 7 is cut off to finish the bore N, i.e. spool bore of a valve spool 1. The inner sleeve 7 formed with the respective grooves A-E is integrally incorporated in the outer sleeve 6 also preformed with the respective ports a-e and then the bore N is machined. |
