Abstract:
An active noise attenuation system ( 10 ) comprises a speaker ( 26 ) in communication with a flow body ( 78 ). The speaker ( 26 ) emits an output for attenuating noise from the flow body ( 78 ). A control unit ( 31 ) communicates with the speaker ( 26 ) and controls the output. A housing ( 14 ) has one volume ( 18 ) acting as a liquid storage chamber and another volume ( 22 ) acting as a speaker chamber.

Description:
[0001]    This application claims priority to Provisional Patent Application Serial No. 60/276,211 filed on Mar. 15, 2001, Provisional Patent Application Serial No. 60/270,769 filed on Feb. 22, 2001, and is a continuation-in-part of U.S. Nonprovisional application Ser. No. 09/931,394 filed on Aug. 16, 2001. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates to a method and system of noise attenuation around an air induction assembly.  
           [0003]    Manufacturers have employed active and passive methods to reduce engine noise within the passenger compartment. Such noise frequently emanates from the engine, travels through the air induction system and emanates out of the mouth of the air intake into the passenger compartment. Efforts have been made to reduce the amount of engine noise traveling through the air induction system. These efforts include the use of both passive devices such as expansion chambers and helmholtz resonators and active devices involving anti-noise generators.  
           [0004]    Active systems use a speaker to create a canceling sound that attenuates engine noise. The sound created is out of phase with the engine noise and combines with this noise to result in its reduction. Generally, this sound is generated in proximity to the mouth of the air intake. In one such system, a control unit, such as a digital signal processor, obtains data from the vehicle engine, creates a predictive amount of engine noise, and thereby generates the appropriate cancellation signals based on the results of this model. The signal is then transmitted to the speaker, which transforms the signal into a canceling sound.  
           [0005]    Typically, active noise systems are positioned in the engine compartment of vehicles. The engine compartments of vehicles are cramped and offer little additional space for an active noise attenuation system. Accordingly, the necessity of locating an active noise attenuation system in proximity to the air intake in the confined space of an engine compartment presents design challenges. Moreover, given the number of systems already present within the engine compartment, there is a need to reduce the number of components added to the engine compartment by the system.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention comprises an active noise attenuation system. The active noise attenuation system has a speaker in proximity to an air intake and serves to emit an output for attenuating noise from the air intake. A control unit controls the speaker, modulating its output to thereby reduce noise. The speaker is housed in a housing that has a first chamber and a second chamber. The first chamber houses the speaker while the second chamber houses the fluid reservoir for fluids such as engine coolant or windshield wiper fluid. By combining the two chambers into a single housing, the amount of space required by the active noise attenuation system and the fluid reservoir is thereby reduced. Moreover, the number of parts within the engine compartment is also reduced.  
           [0007]    The fluid reservoir may be in communication with the windshield wiper system or an engine cooling system. Moreover, a third fluid storage chamber may be used so that the unit may accommodate both fluid for the windshield wiper system and fluid for the engine cooling system. A plate may be disposed within the fluid volume to limit the movement of fluid contained therein. Also, each fluid reservoir may have a transparent sight glass or have a portion of the volume be sufficiently transparent to allow viewing of the fluid levels within the reservoir. By locating the active noise attenuation system near these fluid reservoirs, the unit may also be combined with a battery tray which is typically located within the same vicinity. The unit may also be combined with tubing from the air induction system and also be combined with an air filter. The invention may thus offer a single housing for a significant number of engine components, reducing the amount of space and parts required by them.  
           [0008]    In particular, each chamber may share a common portion of the housing. Thus, a single body may define portions of the fluid storage reservoir, the chamber for the speaker of the noise attenuation system, and the battery tray. Other portions of the invention may be individualized to suit the specific requirements of each engine component. For example, while the engine coolant reservoir may share the same bottom as the speaker chamber, the upper portion of the fluid reservoir may be transparent to permit the observation of fluid levels within the volume. The speaker chamber may be opaque and have particular fittings to support the speaker. In this way, the components are integrated. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:  
         [0010]    [0010]FIG. 1 illustrates the invention, including speaker chamber and liquid storage chamber.  
         [0011]    [0011]FIG. 2 illustrates another variation of the invention including speaker chamber and two liquid storage chambers.  
         [0012]    [0012]FIG. 3 illustrates another view of the invention of FIG. 2, highlighting the transparent portions of the two liquid storage chambers.  
         [0013]    [0013]FIG. 4 illustrates another variation of the invention with an integrated battery tray.  
         [0014]    [0014]FIG. 5 illustrates another variation of the invention showing a flow body with air filter, speaker chamber, liquid storage chambers and battery tray.  
         [0015]    [0015]FIG. 6 illustrates another variation of the invention, highlighting liquid storage chamber, battery tray, air filter and flow body.  
         [0016]    [0016]FIG. 7 illustrates a cross sectional view of another variation of the invention, showing speaker chamber, liquid storage chamber, and baffle contained within liquid storage chamber.  
         [0017]    [0017]FIG. 8 shows a close up of the liquid storage chamber portion of the housing with a fluid sight glass.  
         [0018]    [0018]FIG. 9 illustrates another view of the sight glass of FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]    [0019]FIG. 1 illustrates invention  10 . As shown, housing  14  defines at least two volumes. One volume  22  houses speaker  26  as commonly used for a noise attenuation system. Speaker  26  is controlled by control unit  31  and generates a noise canceling sound which flows out of inlet  30  and inlet  34 . Thus, as known, canceling sound  38  is propagated out of two inlets to attenuate engine noise  42  originating from engine  46 , passing through air induction system  50 , and out air intake  54 .  
         [0020]    By locating speaker  26  and speaker chamber  26  near the liquid storage chambers of an engine cooling system or a fluid reservoir, housing  14  maybe formed to integrate the fluid reservoir of fluid system  58 . Accordingly housing  14  may comprise volume  18  acting as a liquid storage chamber, which is in fluid communication with fluid system  58 , such as an engine cooling system or a windshield wiper fluid system, and volume  22  which serves as an acoustic chamber for speaker  26 . Volume  22  may be formed acoustically as known to maximize noise attenuation from speaker  26 . Housing  14  may comprise a single bottom portion  62  and two top portions, top portion  66  and top portion  70 . Top portion  66  and top portion  70  may be vibration welded to bottom portion  62 . Bottom portion  62  serves to define a portion of volume  18  and volume  22 . Wall  74  divides volume  18  from volume  22 . Top portion  66  may be transparent to permit the observation of the fluid level within volume  18 . Top portion  70  need not be transparent since it houses speaker  26  and not a fluid but may be formed to support speaker  26 .  
         [0021]    As shown in FIG. 1, speaker  26  is in communication with air intake  54 , which itself is in communication with flow body  78 , air induction system  50 , and engine  46 . Flow body  78  is incorporated with bottom portion  62  and comprises tube  82  having end  86  in communication with air induction system and air intake  54  to receive air for air induction system  50  and engine  46 . Housing  14  maybe formed around tube  82 . Also, channel  90  and channel  94  are formed around tube  82  to permit the communication of sound from speaker  26  out inlet  30  and inlet  34  so as to attenuate engine noise  42 . One of ordinary skill in the art can envision the attenuation of sound by directing the canceling sound along different paths relative to the air intake. By combining flow body  78 , speaker  26 , speaker chamber  22 , and liquid storage chamber  18  into housing  14 , space within the engine compartment is conserved and the number of parts within the compartment reduced.  
         [0022]    [0022]FIG. 2 illustrates another variation of the invention. Here, housing  98  comprises three volumes: volume  102  serves as a speaker chamber for speaker  114 , volume  106  serves as a liquid storage chamber for windshield wiper fluid, and volume  110  serves as a liquid storage chamber for engine coolant. As shown in FIG. 2, portions  118 ,  122  and  126  may be transparent to permit the observation of fluid levels within these liquid storage volumes. Also, screw caps  130  and  134  may be provided at the top of volume  106  and  110  to permit the refilling of fluid within these volumes.  
         [0023]    [0023]FIG. 3 illustrates another perspective of housing  98  illustrating portions  126  and  122  which may be transparent.  
         [0024]    [0024]FIG. 4 illustrates another variation of the invention. Housing  138  is comprised of volume  102  for speaker  114 , volume  106  for windshield wiper fluid, volume  110  for engine coolant fluid. In addition, due to the location of speaker  114  and volume  102  within an engine compartment near fender  142  and headlight  144 , housing  102  may also incorporate battery tray  146  to support battery  150 . Fender  142  and headlight  144  are shown to illustrate the location of housing  102  within the engine compartment.  
         [0025]    [0025]FIG. 5 illustrates another variation of the invention. Housing  148  has volume  102  serving as a speaker chamber volume, volume  106  serving as a liquid storage chamber for windshield wiper fluid, and volume  110  serving as a liquid storage chamber for engine coolant fluid. Battery tray  152  serves to support battery  150 , which is oriented differently in this figure than in FIG. 4. Volume  154  is incorporated with housing  148 . Volume  154  serves to house a portion of flow body  158  and an air filter (not shown).  
         [0026]    [0026]FIG. 6 illustrates another variation of the invention showing housing  162  comprising four volumes: volume  166  serves as a speaker chamber volume, volume  170  serves as a fluid storage reservoir for a fluid such as an engine coolant or windshield wiper, volume  174  serves as an air induction volume and volume  178  serves as a volume for storage of battery  150 . Within volume  174  is air filter  182 . Volume  174  is in communication with air intake  186  so as to permit air to reach an air intake system through air filter  182 .  
         [0027]    [0027]FIG. 7 illustrates housing  190 , which comprises volume  194  for housing a speaker and volume  198  for storing a fluid. Volume  198  also has plate  202  level within volume  198  to limit the movement of fluid within this volume. Plate  202  serves as a baffle and may be located at the desired maximum fluid level for volume  198 . Plate  202  may be transparent and may be used to assist in filling the fluid to a maximum level. In addition, housing  190  has three portions, bottom portion  204 , which defines volumes  194  and  198 , and top portion  206  and  208 . Top portion  206  may be transparent. Top portion  206  serves to define the remainder of volume  198  while top portion  208  serves to define the remainder of volume  194 .  
         [0028]    As shown in FIG. 8 and FIG. 9, rather than employing a transparent top portion, a sight glass may be used. Transparent plastic strip  214  may be incorporated with housing  210  and raised slightly above its surface outside of volume  198  to permit the viewing of fluid contained within this volume. As shown in FIG. 9, transparent plastic strip  214  is sandwiched by walls  218  of housing  210 . Thus, walls  218  may be opaque while transparent plastic strip  214  may be clear.  
         [0029]    The aforementioned description is exemplary rather that limiting. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed. However, one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. Hence, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For this reason the following claims should be studied to determine the true scope and content of this invention.