基于磁-熱耦合的揚(yáng)聲器溫度場仿真研究
2023年電子技術(shù)應(yīng)用第8期
李天宇，周靜雷，李佳斌
（西安工程大學(xué) 電子信息學(xué)院，陜西 西安 710600）
摘要： 動圈揚(yáng)聲器在大信號驅(qū)動時(shí)因音圈發(fā)熱嚴(yán)重，會出現(xiàn)音圈斷路、短路和脫膠等熱損壞問題，進(jìn)而導(dǎo)致?lián)P聲器單元損壞。通過建立一款動圈揚(yáng)聲器單元的三維有限元模型，進(jìn)行了基于多物理場耦合的大信號驅(qū)動下的揚(yáng)聲器單元穩(wěn)態(tài)溫度場與應(yīng)力場仿真，并通過試驗(yàn)對仿真結(jié)果進(jìn)行了驗(yàn)證。結(jié)果表明：在恒壓功放的作用下，揚(yáng)聲器單元整體溫度隨音圈電流頻率增大出現(xiàn)先增大后減小的現(xiàn)象，揚(yáng)聲器單元的溫度在額定阻抗點(diǎn)處達(dá)到峰值，等效應(yīng)力集中在音圈骨架與定心支片、振膜連接處，會因?yàn)楦邷匾l(fā)熱故障；同時(shí)分析了音圈出現(xiàn)熱損壞時(shí)對揚(yáng)聲器單元暫態(tài)溫度場的影響。該結(jié)果可為動圈揚(yáng)聲器的溫度監(jiān)測和失效分析提供參考。
中圖分類號：TN912 文獻(xiàn)標(biāo)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(yáng)聲器溫度場仿真研究[J]. 電子技術(shù)應(yīng)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(yáng)聲器溫度場仿真研究[J]. 電子技術(shù)應(yīng)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(yáng)聲器是應(yīng)用最多、最廣泛的揚(yáng)聲器單元，典型的動圈揚(yáng)聲器如圖1所示。揚(yáng)聲器單元在大信號驅(qū)動時(shí)，音圈溫度過高是引發(fā)揚(yáng)聲器單元故障的主要因素之一，長時(shí)間在高溫情況下工作會使揚(yáng)聲器單元出現(xiàn)音圈斷路、短路和脫膠等熱損壞現(xiàn)象[1-3]。高溫還會使釹鐵硼和鐵氧體磁鋼出現(xiàn)退磁現(xiàn)象，使音圈振動減弱從而進(jìn)一步加劇溫升[4]。同時(shí)揚(yáng)聲器單元在工作時(shí)，熱應(yīng)力的增強(qiáng)將加快音圈出現(xiàn)脫膠、斷路等問題，將會減少揚(yáng)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(xiàn)象的出現(xiàn)，可以通過有限元仿真等方法模擬其工作狀態(tài)，并對其分析改進(jìn)[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(xué) 電子信息學(xué)院，陜西 西安 710600）
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