Method for manufacturing conical molding product, and oscillating plate for loudspeaker using same

Abstract

The invention provides a method for manufacturing a conical molding product which is thin, light and yet is of high mechanical strength cheaply in mass production by using a rotation molding technology utilizing synthetic resin to control a direction of orientation of the resin, and particularly provides an oscillating plate for a loudspeaker, which has a high specific modulus E / [rho], large internal loss and excellent acoustic characteristics. The molding die (1) used in the method has a cavity having a conical molding product (3) molded with a cone or a cone frustum with a thin wall in rotation symmetry. An injection part (4) has a molten resin is disposed in a top of the molding die corresponding to the top of the conical molding product. At the very moment that the molten resin is used to fill the cavity, or a period of filling, or just after the filling, at least one of an inner side and an outer side of the molding die of the conical molding product is rotated in a peripheral direction, and thus the orientation of molecules of the resin has components in a generatrix direction and the peripheral direction. The molding die is most suitable for an oscillating plate for a loudspeaker, which is formed by a liquid crystal polymer.

Description

technical field [0001] The present invention relates to a manufacturing method of a conical molded article made of synthetic resin and whose orientation is controlled, and a loudspeaker diaphragm using the same. Background technique [0002] For the vibration plate of the dynamic speaker, it is required to divide the vibration, reduce the natural vibration caused by resonance, and have high conversion efficiency. Therefore, in the vibrating plate, in order to make the specific modulus E / ρ (E: Young's modulus, ρ: density) as large as possible and smooth the frequency characteristics in the high range, a material with a large internal loss is appropriately used, that is, Hard and light raw material. In addition, it is also important that aging damage is small. It is difficult to obtain materials that satisfy all of these conditions at a high level. [0003] Conventionally, cone-shaped paper tubes have been mainly used as diaphragms for loudspeakers. For the purpose of incr...

AI Technical Summary

Problems solved by technology

[0005] Liquid crystal polymers have the characteristic of being able to carry out molecular orientation with a small shear force, and their orientation is high, so the strength in the direction of molecular orientation is high, and the strength in the direction perpendicular to the direction of molecular orientation is low, and it is easy to cracked downside

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