Structure for preventing thermal damage to active noise control speaker

Abstract

A structure for preventing thermal damage to an active noise control speaker includes: an exhaust pipe; a muffler; a speaker in a speaker housing disposed adjacent and connected to the exhaust pipe and the muffler that produces an acoustic wave having a phase that is reverse to a phase of a frequency of the exhaust sound of the exhaust gas; a speaker tube through which low-temperature wind flows into and out of the speaker housing; and an expanded tube portion connected to the speaker tube at an outer circumferential surface thereof, and has a cross-sectional area larger than a cross-sectional area of the speaker tube, in which heated air is discharged from the speaker housing thereby decreasing a temperature of the speaker, thereby improving performance of outputting an acoustic wave of the speaker in comparison with a case in which a temperature of the speaker is high.

What is claimed is: 
     
         1 . A structure for preventing thermal damage to an active noise control speaker, comprising:
 an exhaust pipe connected to a rear side of a vehicle so as to discharge exhaust gas to the outside of the vehicle;   a muffler disposed on the exhaust pipe and reduces exhaust sound of the exhaust gas;   a speaker disposed in a speaker housing adjacent and connected to the exhaust pipe and the muffler, wherein the speaker produces an acoustic wave having a phase that is reverse to a phase of a frequency of the exhaust sound of the exhaust gas;   a speaker tube having an inlet and an outlet through which a low-temperature airflow generated as the vehicle moves, the speaker tube directing the airflow into and out of the speaker housing; and   an expanded tube portion connected to the speaker tube by a fixing portion formed on an outer circumferential surface of the speaker tube, the expanded tube portion having a cross-sectional area larger than a cross-sectional area of the speaker tube;   wherein air heated in the speaker housing is discharged from the speaker housing.   
     
     
         2 . The structure of  claim 1 , wherein in the expanded tube portion, a cross-sectional area in a direction of the inlet of the speaker tube is formed to be larger than a cross-sectional area in a direction of the outlet of the speaker tube, and the cross-sectional area is decreased in a direction from the inlet of the speaker tube to the outlet of the speaker tube. 
     
     
         3 . The structure of  claim 1 , wherein a plurality of expanded tube portions is formed on the speaker tube. 
     
     
         4 . The structure of  claim 1 , wherein the inlet of the speaker tube is formed in an outer surface of the speaker housing directed toward a front side of the vehicle, and the outlet of the speaker tube is formed in the outer surface of the speaker housing directed toward a rear side of the vehicle. 
     
     
         5 . The structure of  claim 1 , wherein the fixing portions are formed on the outer circumferential surface of the speaker tube radially and symmetrically spaced apart from each other on the basis of a center of the speaker tube.