MANUFACTURE OF DIAPHRAGM FOR SPEAKER

摘要

PURPOSE:To form a diaphragm which has an optional thickness distribution and the optional lowest resonance frequency by vacuume forming a film principally of thermoplastic resin. CONSTITUTION:The film consisting principally of thermoplastic resin is used to form a prescribed shape by a vacuum forming, compressed-air forming, or vacuum compressed-air forming method, and the depth of drawing into a forming die and the film area of drawing into the forming die are varied to obtain the diaphragm having an optional thickness distribution. For example, the film 7 consisting principally of thermoplastic resin is formed under a vacuum to prescribed size by using a bottom die 2 equipped with a heating heater 1 and a forming die 6 contained in the recessed part 4 of a top die 5 which has a suction hole 3 by a vacuum pump arranged facing the bottom die 2.