PRODUCTION OF TANK EQUIPPED WITH FILTER

PURPOSE:To easily and simply produce a tank and to reduce product cost, by inserting a filter to integrally form a bottom wall, side walls and an upper wall by blow molding and fixedly holding the outer periphery of the lower part of the filter to the bottom wall. CONSTITUTION:At first, a filter 17 is engaged with a groove 34b to be set to a support mold 34 and the parison 38 extruded from the head 39 of a molding machine 40 is arranged around the filter 17. After clamping, air is blown in the parison 38 from an air blow-in port 35 to form an upper wall 12, a bottom wall 22 and side walls 14 by blow molding. After this time, the filter 17 is fixedly held to the inner peripheral surface of the recessed part 22a of the bottom wall 22 and the inner peripheral surface of the cylindrical part 12a of the upper wall 12. After cooling, the molding machine is opened to take out the molded one and the terminal treatment of nipples 15, 16 are performed and a cap 20 is screwed with the cylindrical part 12a for the cap to make it possible to obtain a predetermined oil tank 11.