Combining with the union volt/bolt for combination type oil filter installation type oil filter device

摘要

PURPOSE:To manufacture a union bolt at a low cost by constructing said union bolt from a main body with special structure and a sleeve. CONSTITUTION:A union bolt 300 for mounting a combination-type oil filter consists of an almost cylindrical main body 360 having a through-hole in the axial direction with a different grade section halfway and a sleeve 370 fixed watertightly inside said through-hole. As a result, the inner peripheral surface in the sleeve 370 forms a full flow passage 310, while the outer peripheral surface forms a by-pass flow passage 320 constituted of a ring space between the outer peripheral surface and the inner peripheral surface of the main body 360, which eliminates the necessity of boring a long hole with small diameter in the axial direction on the peripheral wall of the cylindrical component as is necessary in providing the bypass flow passage by the method heretofore available, and the bolt 300 can be manufactured at a low cost.