Patent Application
20160123208
The present disclosure generally relates to an air induction system. More particularly, the present disclosure relates to an acoustic resonator of an air induction system that attenuates sound waves produced by an engine. In one particular application, the present disclosure relates to an acoustic resonator with a T-shaped tube.
This section provides background information related to the present disclosure which is not necessarily prior art.
Air induction systems are used in motor vehicles and for other applications to transport air from the environment to an engine for combustion. As air moves through the air induction system and into the engine, noise and vibration from the engine may be transmitted and amplified by the passages forming the air induction system. It order to reduce the volume and other characteristics of these noises, it may be desirable to utilize a resonator that vibrates at a frequency equal and opposite to that produced by the engine. In this manner, sound waves may be produced that cancel or reduce the sound waves produced by the engine.
In some situations, it may be desirable to provide a resonator that effectively responds to more than one sound wave, including the frequency thereof, produced by the engine. For example, when the engine is running at low RPM, it may be desirable to have a low frequency resonator to effectively suppress the sound waves produced by the engine. When the engine is running at high RPM, it may be desirable to have a high frequency resonator to effectively suppress the sound waves produced by the engine.
Different types of resonators have been used for automotive and related applications. According to one known type of acoustic resonator, a tube in communication with an engine may extend into an air filter box housing. Sound produced by the engine may be attenuated by adjusting a length that the tube extends into the air filter box housing. The sound produced by the engine may also be attenuated by adjusting a neck area of the tube.
While known resonators have generally proven to be acceptable for their intended purposes, a continued need in the relevant art remains. In this regard, packaging considerations may restrict the application of conventional manners of sound attenuation.
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
According to one particular aspect, the present disclosure provides a resonator for attenuating sound waves produced by an engine. The resonator may include a housing. The housing may include first, second and third portions defining first, second and third working chambers, respectively. The first, second and third portions may cooperate to define a substantially T-shaped resonator operable to attenuate sound produced by the engine.
According to another particular aspect, the present disclosure provides an air induction system for attenuating sound produced by an engine. The air induction system may include a conduit and a resonator. The conduit may transmit a source of intake air to an engine. The resonator may include first, second, and third portions. The first portion may include a first end in fluid communication with the conduit. The second and third portions may be in fluid communication with a second end of the first portion and oriented generally perpendicular to the first portion.
According to yet another particular aspect, the present disclosure provides a method of attenuating sound waves produced by an engine. The method may include providing a resonator in fluid communication with a conduit for delivering a source of intake air to the engine. The resonator may have a T-shape. The method may further include attenuating sound waves produced by the engine having a first frequency with a first effective length defined by the resonator. The method may also include attenuating sound waves produced by the engine having a second frequency with a second effective length defined by the resonator. The method may further include attenuating sound waves produced by the engine having a third frequency with a third effective length defined by the resonator.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings.
With initial reference to
As shown in
In the embodiment illustrated, it will be understood, however, that the present teachings are not limited to this exemplary use. Rather, the present teachings may be readily adapted for use with other combustion engines, including stationary engines. The engine 12 may be an internal combustion engine for a motor vehicle (not shown).
The air filter housing 14 may define a working chamber 22 and may include an inlet 24 in fluid communication with the environment and an outlet 26 in fluid communication with the duct 20. The filter 16 may be disposed between the inlet 24 and the outlet 26. The filter 16 may conventionally filter or clean the air as it travels through the housing 14 from the environment to the duct 20. The duct 20 includes a first end 28 and a second end 29. The first end 28 may pass through the outlet 26 of the housing 14 and may extend into the working chamber 22. The second end 29 of the duct 20 may be secured in fluid communication with the engine 12 in any manner well known in the art.
With continued reference to
The first portion 30a may define a neck and may extend between a first end 34 and a second end 36 along a first axis 38. In one configuration, the first portion 30a may be generally cylindrical defining a working chamber 40 for attenuating sound produced by the engine 12 is attenuated. The working chamber 40 may have a diameter Da. It will be appreciated, however, that the first portion 30a may have alternative geometries within the scope of the present disclosure. The first and second ends 34, 36 of the first portion 30a may be open ends. As illustrated, in an assembled configuration, the first end 34 may be mounted to and in fluid communication with the duct 20. In this regard, the duct 20 may define an opening 41 through which the first end 34 extends. The first end 34 of the first portion 30a may include a flared or radially extending lip portion 42 that fits within the opening 41 of the duct, and helps to provide a more secure mount between the first end 34 and the duct 20. The first end 34 may be mounted or otherwise secured to the duct 20 by welding, adhesives, mechanical fasteners, press fitting, or any other suitable fastening technique known in the art.
The second end 36 of the first portion 30a may be mounted to and in fluid communication with the second and third portions 30b, 30c. The second end 36 may be mounted to the second and third portions 30b, 30c by welding, adhesives, mechanical fasteners, press fit, or any other suitable fastening technique known in the art. As illustrated in
The second portion 30b may be in fluid communication with the third portion 30c and with the first portion 30a. The third portion 30c may, likewise, be in fluid communication with the second portion 30b and with the first portion 30a. In one configuration, the second and third portions 30b, 30c may be similarly sized and shaped. In this regard, the second portion 30b may extend between a first end 54 and a second end 56 along a second axis 58. The first and second ends 54, 56 of the second portion 30b may be open ends. In one configuration, the second portion 30b may be a cylinder defining a working chamber 60b in which sound produced by the engine 12 is attenuated. In this regard, the working chamber 60b may define a diameter Db. It will be appreciated, however, that the second portion 30b may have alternative geometries within the scope of the present disclosure.
The third portion 30c may extend between a first end 62 and a second end 64 along a third axis 66. The first and second ends 62, 64 of the third portion 30c may be open ends. In one configuration, the third portion 30c may be a cylinder defining a working chamber 60c in which sound produced by the engine 12 is attenuated. In this regard, the working chamber 60c may define a diameter Dc. It will be appreciated, however, that the third portion 30c may have alternative geometries within the scope of the present disclosure.
With particular reference to
In one configuration, the second end 56 of the second portion 30b may be adjustably coupled to the second end 48 of the coupling member 44. For example, the second end 56 of the second portion 30b may slide within, or otherwise telescope relative to, the second end 48 of the coupling member 44, such that a distance Lb between the first axis 38 and the first end 54 of the second portion 30b can be increased, decreased, or otherwise adjusted based on particular applications. Similarly, the second end 64 of the third portion 30c may be adjustably coupled to the third end 50 of the coupling member 44. For example, in one configuration, the second end 64 of the third portion 30c may slide within, or otherwise telescope relative to, the third end 50 of the coupling member 44, such that a distance Lc between the first axis 38 and the first end 62 of the third portion 30c can be increased, decreased, or otherwise adjusted based on particular applications. In another configuration, the second end 56 of the second portion 30b may be removably coupled to the second end 48 of the coupling member 44, and the second end 64 of the third portion 30c may be removably coupled to the third end 50 of the coupling. In this regard, adjustability of the second and third portions 30b, 30c can be accomplished by removing second and third portions 30b, 30c having first lengths, and replacing the second and third portions 30b, 30c having first lengths with second and third portions 30b, 30c having second lengths that are different than the first lengths.
As illustrated in
Operation of the air induction system 10 will now be described in more detail. An engine 12 will produce sound waves at various frequencies. For example, dominant frequencies may correspond to peak revolutions-per-minute prior to gear shifting. During operation of the engine 12, air travels along the duct 20 in a first direction A. Sound waves from the engine 12 noise travel along the duct 20 in an opposite direction B. The conduit 20 is oriented generally perpendicular to the neck or first portion 30a of the resonator 18. Such a resonator is conventionally referred to in the pertinent art as a Helmholtz resonator 18.
The resonator 18 of the present teachings is particularly adapted to attenuate three distinct frequencies based on different length combinations of the first, second, and third portions 30a, 30b, 30c. Explaining further, the resonator 18 of the present teachings is particularly adapted to attenuate first, second, and third frequency peaks FP1, FP2, FP3. The lengths La, Lb, and Lc of the first, second and third portions 30a, 30b and 30c, respectively, can be selected and/or adjusted to provide a Helmholtz, or half (½) wave resonator, and a quarter (¼) wave resonator.
The frequency peaks of the quarter (¼) wave resonators are given by the equation:
The frequency peak of the half (½) wave resonator is given by the equation:
where, ν is the speed of sound in air, Aa is the cross-sectional area of the first portion 30a, Vb is the static volume of the second portion 30b, Vc is the static volume of the third portion 30c, and where the resonator 18 defines first, second, and third effective lengths Leff1, Leff2, Leff3:
The first, second and third lengths La, Lb, and Lc and the first, second and third diameters Da, Db, and Dc can be selected such that the frequency peaks FP1, FP2, and FP3 of the sound waves produced by the resonator 18 correspond to, and thus attenuate, the dominant frequencies of the sound waves produced by the engine 12. To change the first, second and/or third frequency peak FP1, FP2, and/or FP3, the user can adjust the lengths La, Lb, and Lc by adjusting the relative position of the first, second and/or third portion 30a, 30b, 30c relative to the first, second or third end 46, 48, 50, respectively, of the coupling member 44, in the manner described above.
According to a first non-limiting example, the first portion 30a has a length La of approximately 200 mm, the second portion 30b has a length Lb of approximately 200 mm, and the third portion 30c has a length Lc of approximately 150 mm. In this example, the resonator 18 is particularly adapted to attenuate a first frequency F1 of approximately 171 Hz, a second frequency F2 of approximately 504 Hz, and a third frequency F3 of approximately 702 Hz.
According to a second non-limiting example, the first portion 30a has a length La of approximately 200 mm, the second portion 30b has a length Lb of approximately 200 mm, and the third portion 30c has a length Lc of approximately 100 mm. In this example, the resonator 18 is particularly adapted to attenuate a first frequency F1 of approximately 182 Hz, a second frequency F2 of approximately 558 Hz, and a third frequency F3 of approximately 806 Hz.
The foregoing description is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
