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。
中圖分類號：TN912 文獻標志碼：A DOI: 10.16157/j.issn.0258-7998.223511
中文引用格式： 李天宇，周靜雷，李佳斌. 基于磁-熱耦合的揚聲器溫度場仿真研究[J]. 電子技術應用，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，周靜雷，李佳斌. 基于磁-熱耦合的揚聲器溫度場仿真研究[J]. 電子技術應用，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
動圈揚聲器是應用最多、最廣泛的揚聲器單元，典型的動圈揚聲器如圖1所示。揚聲器單元在大信號驅動時，音圈溫度過高是引發揚聲器單元故障的主要因素之一，長時間在高溫情況下工作會使揚聲器單元出現音圈斷路、短路和脫膠等熱損壞現象[1-3]。高溫還會使釹鐵硼和鐵氧體磁鋼出現退磁現象，使音圈振動減弱從而進一步加劇溫升[4]。同時揚聲器單元在工作時，熱應力的增強將加快音圈出現脫膠、斷路等問題，將會減少揚聲器單元的使用壽命甚至完全損壞。為了避免這些熱失效現象的出現，可以通過有限元仿真等方法模擬其工作狀態，并對其分析改進[5-7]。
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作者信息：
李天宇，周靜雷，李佳斌
（西安工程大學 電子信息學院，陜西 西安 710600）
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