基于磁-热耦合的扬声器温度场仿真研究
2023年电子技术应用第8期
李天宇，周静雷，李佳斌
（西安工程大学 电子信息学院，陕西 西安 710600）
摘要： 动圈扬声器在大信号驱动时因音圈发热严重，会出现音圈断路、短路和脱胶等热损坏问题，进而导致扬声器单元损坏。通过建立一款动圈扬声器单元的三维有限元模型，进行了基于多物理场耦合的大信号驱动下的扬声器单元稳态温度场与应力场仿真，并通过试验对仿真结果进行了验证。结果表明：在恒压功放的作用下，扬声器单元整体温度随音圈电流频率增大出现先增大后减小的现象，扬声器单元的温度在额定阻抗点处达到峰值，等效应力集中在音圈骨架与定心支片、振膜连接处，会因为高温引发热故障；同时分析了音圈出现热损坏时对扬声器单元暂态温度场的影响。该结果可为动圈扬声器的温度监测和失效分析提供参考。
中图分类号：TN912 文献标志码：A DOI: 10.16157/j.issn.0258-7998.223511
中文引用格式： 李天宇，周静雷，李佳斌. 基于磁-热耦合的扬声器温度场仿真研究[J]. 电子技术应用，2023，49(8)：103-107.
英文引用格式： Li Tianyu，Zhou Jinglei，Li Jiabin. Simulation of loudspeaker temperature field based on magnetic-thermal coupling[J]. Application of Electronic Technique，2023，49(8)：103-107.
中文引用格式： 李天宇，周静雷，李佳斌. 基于磁-热耦合的扬声器温度场仿真研究[J]. 电子技术应用，2023，49(8)：103-107.
英文引用格式： Li Tianyu，Zhou Jinglei，Li Jiabin. Simulation of loudspeaker temperature field based on magnetic-thermal coupling[J]. Application of Electronic Technique，2023，49(8)：103-107.
Simulation of loudspeaker temperature field based on magnetic-thermal coupling
Li Tianyu，Zhou Jinglei，Li Jiabin
(School of Electronic Information，Xi'an Polytechnic University，Xi'an 710600，China)
Abstract： Moving coil loudspeaker may experience thermal damage such as open circuit, short circuit, and debonding when driven by large signals due to severe heating of the voice coil, resulting in damage to the speaker unit. By establishing a three-dimensional finite element model of a moving coil loudspeaker unit, the steady-state temperature and stress fields of the speaker unit were simulated under large signal driving based on multi physical field coupling, and the simulation results were verified through experiments. The results show that under the action of a constant voltage power amplifier, the overall temperature of the speaker unit first increases and then decreases with the increase of the frequency of the voice coil current. The temperature of the speaker unit reaches its peak at the rated impedance point, and the equivalent stress is concentrated at the connection between the voice coil skeleton, centering support, and diaphragm, which may cause heating faults due to high temperature. At the same time, the impact of thermal damage to the voice coil on the transient temperature field of the speaker unit was analyzed. This result can provide reference for temperature monitoring and failure analysis of moving coil loudspeaker.
Key words : magnetothermal coupling；moving coil loudspeaker；finite element method；numerical simulation
0 引言
动圈扬声器是应用最多、最广泛的扬声器单元，典型的动圈扬声器如图1所示。扬声器单元在大信号驱动时，音圈温度过高是引发扬声器单元故障的主要因素之一，长时间在高温情况下工作会使扬声器单元出现音圈断路、短路和脱胶等热损坏现象[1-3]。高温还会使钕铁硼和铁氧体磁钢出现退磁现象，使音圈振动减弱从而进一步加剧温升[4]。同时扬声器单元在工作时，热应力的增强将加快音圈出现脱胶、断路等问题，将会减少扬声器单元的使用寿命甚至完全损坏。为了避免这些热失效现象的出现，可以通过有限元仿真等方法模拟其工作状态，并对其分析改进[5-7]。
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作者信息：
李天宇，周静雷，李佳斌
（西安工程大学 电子信息学院，陕西 西安 710600）
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