Manufacturing method for diffuser

Abstract

A manufacturing method for a diffuser comprises a first process of forming a first molded component, by gradually forging a cylindrical solid material having fiber flow extending in an axial direction from an axial direction thereof, the first molded component including a flange section having a central hole section, and a bottomed cylindrical section having a communication hole leading to one end, in the axial direction, of the flange, and communicating with the hole section, and having fiber flow that is flowing substantially in the axial direction without being cut, and a second process of forming a second molded component, by split molding a peripheral groove using split dies at the outer periphery of the bottomed cylindrical section of the first molded component, including a flange having a central hole section, and a bottomed cylindrical section having a communication hole leading to one end, in the axial direction, of the flange, and communicating with the hole section, and having the peripheral groove formed without cutting fiber flow. The embodiment provides a manufacturing method for a diffuser that can be produced with high yield and at low cost, while doing away with locations where fiber flow is cut and that has no gas leakage.

What is claimed is: 
     
         1 . A manufacturing method for a diffuser comprising a flange with a central hole section and an outer engagement section, and a bottomed cylindrical section having a communicating hole that leads to one end, in an axial direction, of the flange and communicates with the hole section, with a peripheral groove formed on an outer peripheral section of the bottomed cylindrical section, and a plurality of expulsion ports that communicate with an airbag extending radially to the bottom section of the communication hole, comprising:
 a first process of forming a first molded component, by gradually forging a cylindrical solid material from an axial direction thereof using the cylindrical solid material having fiber flow extending in an axial direction in order to prevent material loss, the first molded component including a flange section having a central hole section, and a bottomed cylindrical section having a communication hole leading to one end, in the axial direction, of the flange, and communicating with the hole section, and having fiber flow that is not cut and flowing substantially in the axial direction; and   a second process of forming a second molded component, by split molding a peripheral groove using split dies at the outer periphery of the bottomed cylindrical section of the first molded component, the second molded component including a flange having a central hole section, and a bottomed cylindrical section having a communication hole leading to one end, in the axial direction, of the flange, and communicating with the hole section, and having the peripheral groove formed without cutting fiber flow.   
     
     
         2 . A manufacturing method for a diffuser comprising a flange with a central hole section and an outer engagement hole section, and a bottomed cylindrical section having a communicating hole that leads to one end, in an axial direction, of the flange and communicates with the hole section, with a peripheral groove formed on an outer peripheral section of the bottomed cylindrical section, and a plurality of expulsion ports that communicate with an airbag extending radially to the bottom section of the communication hole, comprising:
 an advance process of forming an intermediate molded component, by gradually forging a cylindrical solid material that has fiber flow extending in an axial direction using a multistage former or press, the intermediate molded component including a flange, and a cylindrical section of a smaller diameter than a step section that extends axially outward from a central section at one end, in the axial direction, of the flange, via the step section, and having fiber flow flowing in substantially the axial direction without being cut;   a first process of forming a first molded component by press forming the intermediate component from the axial direction using a press unit, the first molded component comprising a flange having a central hole section, and a bottomed cylindrical section of smaller diameter than the outer diameter of a step section having a communication hole that extends axially outwards from a central section of one end of the flange in the axial direction and communicates with the hole section, with fiber flow flowing in a substantially axial direction without being cut; and   a second process of forming a second molded component by a split mold upset process so as to expand only a tip end of the bottomed cylindrical section in a state where a boundary division of the step section and the bottomed cylindrical section of the first molded component is restrained by split dies, the second molded component including a flange having a central hole section, and a bottomed cylindrical section having a peripheral groove and extending axially outward at the same diameter as the outer diameter of the step section from the center section of one end, in the axial direction, of the flange, at a middle of the axial length of the outer periphery of the bottomed cylindrical section, and having the peripheral groove formed without cutting fiber flow.