| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem in manufacturing a bronze cast flow meter. SOLUTION: This manufacturing method of a flow meter comprising a storage chamber to store an impeller, an inflow passage to communicate an inflow hole formed in an inner wall of the storage chamber with an inflow side opening outside, and an outflow passage to communicate an outflow hole formed in the inner wall of the storage chamber with an outflow side opening outside comprises a first step of preparing a material, a second step of substantially forming the inner wall of the storage chamber by inserting a first punch in the material to form a hollow portion, a third step of substantially forming each inner wall of the inflow passage and the outflow passage by inserting second and third punches in the material to form two hollow portions, and a fourth step of forming an inflow hole and an outflow hole by removing a bulkhead located on end sides of the second and third punches, and a substantially cylindrical guide sleeve to guide the inserted punches is movably housed on at least one of the second and third punches.
|
