| 摘要 |
PURPOSE:To improve acoustic characteristics by bonding a sheet member formed by kneading graphite powder to a substance having a coking property and where the graphite is oriented in the facial direction to both sides of a porous core to give high strength and elasticity to the titled diaphragm. CONSTITUTION:The sheet member 2 is adhered to a metallic honey-comb core 1. As the sheet member 2, it is formed by kneading graphite power to a coking substance such as polyvinyl chloride, polycarbonate, coal tar or asphalt pitch, the result is rolled into a sheet by a rolling roller to orient the graphite powder in the facial direction. The sheet member is subjected to carbide processing in an inert gas at 500-1,000 deg.C or graphite processing at a high temperature of 2,000-3,000 deg.C to increase the strength and the longitudinal elastic coefficient. Thus, the bending rigidity is improved to boost the split vibration region thereby improving the acoustic characteristic. |
