DESC:FIELD OF DISCLOSURE

The present disclosure relates to air intake systems of vehicles.

DEFINITIONS

The expression ‘fender’ used henceforth is part of an automobile body that frames a wheel well. A ‘wheel well’ is a part which protects the internal components under the hood of a vehicle from debris thrown by a wheel during operation.

The expression ‘resonator’ used henceforth is a device used to muffle the noise produced by the engine.

BACKGROUND

Movement of air from an inlet of an air intake system to an internal combustion engines produces vibrations due to air pressure fluctuations and thereby produces undesirable noise/sound emissions. A resonator is commonly used to muffle down the produced noise. Conventionally the resonator is mounted near the engine of the vehicle. However, the area near the engine compartment has space constraints and to counter thereby provide limitations on accommodating comparatively large sizes of resonators. With traditional resonators, particularly the Helmholtz resonator the step-up requires a separate reservoir to be attached to the air flow conduit system. This causes problems of space allocation.

Accordingly, to reduce/minimise air pressure fluctuations and thereby undesirable noise/sound emissions, a variety of resonators have been used in the prior art.

For example, Japanese patent publication JP2004183492 includes an air duct and a resonator. The air duct is connected to the resonator. The air duct and resonator are formed by a member that is integrally formed with a first part of the air duct connected to a second part of the air duct and a first part of the resonator connected to a second part of the resonator.

US 5424494 patent discloses a noise-attenuating internal combustion engine. Noise is attenuated by a resonator having an inlet pipe leading to an expansion chamber and an outlet pipe leading from the expansion chamber. The expansion chamber functions as a Helmholtz resonator by providing the resonator with one or more apertures between the outlet pipe and the expansion chamber.

US2008236534 patent publication discloses a resonator for the air intake system of a motor vehicle which has housing and at least one resonator chamber enclosed by the housing. At least one air intake opening for fresh air is provided in the housing and opens into the resonator chamber. At least one air exhaust opening for fresh air is provided in the housing and opens into the resonator chamber. The at least one air exhaust opening is also an intake opening of an auxiliary device, especially an air compressor.

WO9849440 patent publication discloses an integrated duct and a resonator for an automobile engine air induction system. The integrated duct and the resonator is installed on an engine between the air cleaner and throttle body to establish a flow path for inducted air flow to the engine through a duct portion of the component. One or more resonator chambers are provided which can be of differing volumes to be tuned to different noise frequency ranges. Fluid communication between the duct portion and each resonator chamber can either be defined by a cut away region to create an expansion chamber and/or with one or more small openings to create a Helmholtz resonator.

KR2009123215 patent publication discloses an air cleaner with a resonator. The air cleaner is integrated with a resonator and is provided to facilitate tuning work of the resonator by inserting a tuning pipe into the resonator and controlling the length of the tuning pipe. The air cleaner and the resonator are integrated

US6804360 patent discloses an air intake noise reduction apparatus for automotive vehicle. The apparatus includes four intake passages of varying lengths with three partition walls.

In all above mentioned prior art disclosures the noise reduction apparatus are disposed in a space-constrained engine compartment of the vehicle and hence the noise-attenuation is comparatively ineffective.

Accordingly, there is a need for an air intake resonator system for vehicles that minimizes / absorbs vibrations and minimizes noise/sound emissions reliably in a cost effective manner.

OBJECTS

Some of the objects of the system of the present disclosure which at least one embodiment herein satisfies are as follows:

It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.

Yet another object of the present disclosure is to provide an air intake system for feeding air to the engine of a vehicle that minimizes / diffuses the pressure / velocity of air flow.

Still another object of the present disclosure is to provide an air intake system for feeding air to the engine of a vehicle that minimizes noise/sound emissions.

An object of the present disclosure is to provide an air intake system for feeding air to the engine of a vehicle that is reliable.

Yet another object of the present disclosure is to provide an air intake system for feeding air to the engine of a vehicle that is easy to manufacture and thereby is cost effective.

Another object of the present disclosure is to provide an air intake system for feeding air to the engine of a vehicle that provides higher transmission loss improvement over the frequency range of the engine operation.

Yet another object of the present disclosure is to provide an air intake system for feeding air to the engine of a vehicle that eliminates the pressure drop problem.

Also another object of the present disclosure is to provide an air intake system for feeding air to the engine of a vehicle that eliminates the water wading risk.

A further object of the present disclosure is to provide an air intake system for feeding air to the engine of a vehicle that has a comparatively lower cost to manufacture.

Another object of the present disclosure is to provide an air intake system for feeding air to the engine of a vehicle that provides the flexibility of being fine-tuned for a specific frequency.

Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.

SUMMARY

In accordance with the present disclosure there is provided an air intake system for feeding air to the engine of a vehicle, the system comprising an expansion chamber mounted inline between the air inlet of the system and the engine, the expansion chamber having a profiled wall defining a cavity having a varying cross section, an inlet and an outlet defined in the wall along parallel axes configured to permit ambient air to enter through the inlet, expand in the chamber and flow in a direction substantially parallel but in opposite direction of the direction of entry of the air into the expansion chamber and a conduit fitted between the outlet of the expansion chamber and inlet of the engine, a portion of the conduit distal from the expansion chamber outlet having a varying cross section.

Typically, the area of the cross section of the cavity decreases as the cavity approaches the inlet and outlet of the expansion chamber. Additionally, the conduit further consists of at least two pipes, one of the pipes with uniform cross section and another pipe with varying cross section. Also, an air filter system is intermediately connected between the conduit and the engine. Typically, the inlet and the outlet are tubular openings of one of cast directly on the surface of the expansion chamber and externally attached to the expansion chamber. Additionally, the expansion chamber has a ‘C’ shape, wherein one end of the ‘C’ shape constitutes the inlet and other end constitutes the outlet, with length of the outlet is greater than the length of the inlet and other end of the outlet connected to one end of the conduit. Also, the shape of the inlet is polygonal and the shape of the outlet is elliptical.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The disclosure will now be explained in relation to the accompanying drawing, in which:

Figure 1a illustrates a conventional air intake system disposed in an engine compartment region, wherein the air intake system includes an air intake pipe, an air outlet pipe and a noise/sound attenuation apparatus;

Figure 1b illustrates a schematic representation of the noise/sound attenuation apparatus of Figure 1a; wherein the noise/sound attenuation apparatus is a Helmholtz resonator;

Figure 2a illustrates a perspective view of an air inlet resonator system connected to an air filter in accordance with an embodiment of the present disclosure, wherein the air inlet resonator system includes an expansion chamber and at least one profiled conduit;

Figure 2b illustrates another perspective view of an air inlet resonator system of Figure 2a;

Figure 3a illustrates another view of the air inlet resonator system of Figure 2a; wherein the expansion chamber is disposed in a fender area of the vehicle;

Figure 3b illustrates a closer view of the expansion chamber of the air inlet resonator system of Figure 3a;

Figure 4a illustrates a perspective view of the expansion chamber of Figure 2a;

Figure 4b illustrates an another perspective view of the expansion chamber of Figure 2a;

Figure 4c illustrates yet another perspective view of the expansion chamber of Figure 2a;

Figure 5a illustrates a front view of the expansion chamber of Figure 2a;

Figure 5b illustrates a cross-sectional view along the sectional line a-a of the expansion chamber of Figure 5a;

Figure 5c illustrates a cross-sectional view along the sectional line b-b of the expansion chamber of Figure 5a;

Figure 5d illustrates a cross-sectional view along the sectional line c-c of the expansion chamber of Figure 5a;

Figure 5e illustrates a cross-sectional view along the sectional line d-d of the expansion chamber r of Figure 5a;

Figure 5f illustrates a cross-sectional view along the sectional line e-e of the expansion chamber of Figure 5a;

Figure 5g illustrates a cross-sectional view along the sectional line f-f of the expansion chamber of Figure 5a;

Figure 6 illustrates a schematic representation of the expansion chamber in accordance to the present disclosure;

Figure 7 illustrates a graphical representation of the amplitude of noise/sound at different frequencies;

Figure 8a illustrates a graph plotted of frequency vs sound pressure level for a frequency range between 50 Hz and 300 Hz;

Figure 8b illustrates a graph plotted of frequency vs sound pressure level for a frequency range between 100 Hz and 450 Hz;

Figure 9a illustrates a sound pressure level based heat graph represented on a graph plotted of frequency vs engine speed with no reservoir attached in the system;

Figure 9b illustrates a sound pressure level based heat graph represented on a graph plotted of frequency vs engine speed with a reservoir attached in the system; and

Figure 10 illustrates a graph plotted of frequency vs engine speed.

DETAILED DESCRIPTION

An air intake system for feeding air to the engine of a vehicle of the present disclosure will now be described with reference to the embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.

The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Figure 1a of the accompanying drawing illustrates a conventional air intake system 100. The air intake system 100 is disposed in the region near an engine compartment (not illustrated in Figures) of vehicles. The air intake system 100 passes the air from the atmosphere to the engine of the vehicles. The air intake system 100 includes an air inlet pipe 110, a noise/sound attenuator 120 and an air outlet pipe 130. The air inlet pipe 110 passes air to the air outlet pipe 130. The air outlet pipe 130 further passes the air to the engine of the vehicles. However, as the air passes from the air inlet pipe 110 to the air outlet pipe 130, at least a portion of air passes to the noise/sound attenuator 120 that is separately connected to at least one of the air inlet pipe 110 and the air outlet pipe 130. Typically, the noise/sound attenuation apparatus 120 is a Helmholtz resonator 100.

The engine of the vehicle generates vibrations and unwanted noise/sound. This unwanted noise/sound is transmitted from the engine to the air outlet pipe 130. The air outlet pipe 130 further passes the unwanted noise/sound partially to the noise/sound attenuator 120 and partially to the air inlet pipe 110. The air inside the noise/sound attenuator 120 absorbs and thereby minimizes the unwanted noise/sound of specific frequency. However, the unwanted noise/sound of a frequency other than specific frequency is not minimized. Also, the unwanted noise/sound is partially passed directly to the atmosphere or the interior of the vehicle thereby creating noise pollution.

Further, the air intake system 100 is disposed in the region near the engine compartment (not illustrated in Figures) of the vehicle. The region near the engine compartment has limited space availability. Hence, there is limitation for accommodating comparatively large size of the noise/sound attenuation apparatus 120.

Hence, there is a need for an air intake resonator system that minimizes / diffuses pressure / velocity of the air flow and thereby minimizes noise/sound.

The air intake resonator system as disclosed minimizes / diffuses the pressure / velocity of the air flow and minimizes noise/sound emissions at a specific frequency as well as at least a broad band of frequencies.

Figure 1b illustrates a schematic representation of the noise/sound attenuation apparatus of Figure 1a; wherein the noise/sound attenuation apparatus is a Helmholtz resonator. Figure 1b also illustrates an analogy with spring mass system (single degree of freedom is drawn) wherein:
m: mass;
K: Stiffness;
= Input transient pressure = ;
= Neck radius of resonator;
= Radius of the cavity/sphere;
= Input Force = ;
= sprung mass;
= damping coefficient; and
K = stiffness.

Figure 2a and Figure 2b illustrate the air intake system for feeding air to the engine of a vehicle 200 of the present disclosure. In one embodiment, the air intake system for feeding air to the engine of a vehicle 200 includes an expansion chamber 210 and a conduit 216. The air intake system for feeding air to the engine of a vehicle 200 includes an upstream end through which air enters the expansion chamber 210 and a downstream end through which air passes from the expansion chamber 210 to the conduit 216 to the engine (not shown in Figures) through an air filter 222.

In one embodiment and as shown in Figure 3a and Figure 3b, the expansion chamber 210 is disposed in a fender area and dirty side of air intake system thereby utilizing the available space of the fender area. The expansion chamber 210 is embedded along the atmospheric air inlet line and is an integral part of the air inlet line. This integration eliminates the need of separate resonators and protruded cavities thereby the expansion chamber 210 may be easily accommodated in the fender area. The expansion chamber 210 functions as a noise/sound absorber, an air vibration and pressure fluctuation damper, a broad-band noise attenuator and an air distributor.

As shown in Figures 4a to 4c, the expansion chamber 210 includes an inlet 212, a profiled cavity and an outlet 214. The inlet 212 and the outlet 214 of the expansion chamber 210 are located in parallel. The expansion chamber 210 has a ‘C’ shape. One end of the ‘C’ shape consists the inlet 212 and the other end of the ‘C’ shape consists the outlet 214. The inlet 212 and the outlet 214 are tubular openings of one of cast to the expansion chamber 210 and manufactured and assembled externally to the surface of the expansion chamber 210. Figure 5a illustrates the front view of the expansion chamber 210. Figures 5b to 5g illustrate the cross-sectional views at various sections of the expansion chamber 210. The inlet 212 has a shape whose cross-section closely resembles a polygon, preferable one of a pentagon and a rectangle. The outlet 214 has a cross-section closely resembling a circle preferably an ellipse. The expansion chamber 210 includes a cavity with one end having a higher cross-sectional area and one end with a smaller cross-sectional area and the cross-sectional area decreases as the cavity profile approaches the inlet 212 and outlet 214 of the expansion chamber 210. The axis of the inlet 212 and outlet 214 join the expansion chamber 210 at an end of the cavity opposite to one having an enlarged cross-sectional area. Figure 6 illustrates a schematic representation of the expansion chamber 210 wherein:

The inlet 212 transmits atmospheric air into the expansion chamber 210. The inlet 212 imposes no restriction on the intake of air and thereby there is no parasitic load imposed on the engine. The inlet 212 conveys fresh outside air to the expansion chamber 210. The air from the expansion chamber 210 is conveyed to the outlet 214. The other end of the outlet 214 is connected to the conduit 216. The air from the outlet 214 is conveyed to the conduit 216 to the internal combustion engine via an air filter 222.

The engine of the vehicle generates vibrations and unwanted noise/sound. This unwanted noise/sound is transmitted from the engine to the conduit 216 and travels in a direction opposite to the direction of flow of the air. The conduit 216 further passes the unwanted noise/sound to the expansion chamber 210 through the outlet 214. The outlet pipe 214, the expansion chamber 210 and the inlet 212 provides a major impedance change to the vibrations and the unwanted noise/sound generated by the internal combustion engine. More specifically, the unwanted noise/sound entering the expansion chamber 210 via the outlet 214 encounters a profiled cavity generated by the varying cross-sections of the expansion chamber 210 as shown in Figures 5b to 5g. The profiled cavity is determined by the profile of the fender area and appropriate clearances, the volume, and the impedance requirement of the targeted frequency and the tonal quality. Thus the varying cross-sections of the expansion chamber 210 provide major impedance change that minimizes the vibrations and broad band of the unwanted noise/sound over a targeted frequency range. Thus the expansion chamber 210 functions as the noise/sound absorber, the air vibration damper and the broad-band noise attenuator.

In one embodiment, the inlet 212 and the outlet 216 are of different lengths with the length of the outlet 214 preferably being greater than the length of the inlet 212. This varying length of the inlet 212 and the outlet 214 contributes to the air attenuation.

Additionally, specific frequency noise attenuation is attained within the profiled cavity which acts as a Helmholtz resonator with varying dynamics. This is done by one or more pipes extending from the expansion chamber 210.

In one embodiment, the expansion chamber 210 is fabricated by blow-moulding technology as a single plastic part. In another embodiment the expansion chamber 210 is formed by assembling several injection-moulded parts together.

The conduit 216 has a first operative end connected to the air filter 222 and a second operative end connected to the expansion chamber 210. In one embodiment, the conduit 216 is formed by assembly of at least two pipes, one pipe 218a of uniform diameter and other pipe 218b of varying diameter and at least one bend 220a and 220b.

The air intake system for feeding air to the engine of a vehicle 200 has comparatively less pressure drop problem than that of a Helmholtz resonator or a cold air box. Typically, the air intake system for feeding air to the engine of a vehicle 200 reduces/eliminates noise characteristics. The air intake system for feeding air to the engine of a vehicle 200 is disposed on the dirty side of the air intake orifice and hence clears water wading test that is critical for Design, Validation and Plan (DVP) for the air intake system.

The present disclosure will now be explained with the help of the following non-limiting example. Two tests were conducted wherein the Test 1 was conducted with a conventional air intake system with a Helmholtz resonator 100 and Test 2 was conducted with the air intake system for feeding air to the engine of a vehicle 200 with an expansion chamber 210 and conduit 216 in accordance with the present disclosure. The test was performed to identify the transmission loss equal to or greater than amplitude 20 dB.

Test 1: The conventional air intake system with the Helmholtz resonator 100 was subjected to a test wherein the Helmholtz resonator 100 was disposed in the engine compartment region of a vehicle. It was observed and noted that the noise/sound generated by the internal combustion engine of the vehicle had comparatively low transmission losses and hence problematic dips/reduction in frequency were observed that required high volume of the Helmholtz resonator 100. The unwanted noise/sound was observed in frequencies below 400Hz. Figure 7 illustrates the graphical representation represented by curve 320, wherein the graphical representation represents the amplitude (dB) of noise/sound at different frequencies. A problematic dip in amplitude at frequency of 272 Hz was intense.

Test 2: The air intake system for feeding air to the engine of a vehicle 200 with an expansion chamber 210 and profiled conduit 220 was subjected to test wherein the air intake resonator system 200 was of size and shape that prevented problematic dips occurring in the range of 200Hz to 300Hz. The expansion chamber 210 of the the air intake system for feeding air to the engine of a vehicle 200 was disposed in the fender area of the vehicle. Figure 7 illustrates the graphical representation represented by curve 310, wherein the graphical representation represents the amplitude (dB) of noise/sound at different frequencies, wherein improvement amplitude of 42 dB was observed because of increase in transmission loss of about 10dB RMS.

The frequency vs amplitude graph 300 as illustrated in Figure 7 showcases two bands of frequencies, the 4th band covering a frequency range between 50 Hz and 400 Hz and a 6th band covering a frequency range between 750 Hz and 950 Hz. In both these bands, the transmission loss curve for a baseline system 320 has lower amplitude than the transmission loss curve for a system with an attached reservoir 310.

Figure 8a illustrates a graph plotted of frequency vs sound pressure level for a frequency range between 50 Hz and 300 Hz and represented with the number 350. Figure 8b illustrates a graph plotted of frequency vs sound pressure level for a frequency range between 100 Hz and 450 Hz and represented with the number 375. From both the graphs it could be concluded that the sound pressure levels for the system attached with a reservoir is lower than the sound pressure level for the baseline system.

Figure 9a illustrates a sound pressure level based heat graph represented on a graph plotted of frequency vs engine speed with no reservoir attached in the system and represented with the number 450. Figure 9b illustrates a sound pressure level based heat graph represented on a graph plotted of frequency vs engine speed with a reservoir attached in the system and represented with the number 475. From the comparison of the heat graphs it could be concluded that the sound pressure level for the system attached with a reservoir is less than the sound pressure level of the baseline system.

Figure 10 illustrates a graph plotted of frequency vs engine speed and represented with the number 500. From the graph it could be concluded that the sound pressure level for the system attached with the reservoir is lower than the sound pressure level of the baseline system.

TECHNICAL ADVANCEMENTS

The air intake resonator system in accordance with the present disclosure has several technical advantages including but not limited to the realization of:

• an air intake system for feeding air to the engine of a vehicle that minimizes / diffuses the pressure / velocity of air flow;

• an air intake system for feeding air to the engine of a vehicle that minimizes noise/sound emissions;

• an air intake system for feeding air to the engine of a vehicle that is reliable;

• an air intake system for feeding air to the engine of a vehicle that is easy to manufacture and thereby is cost effective;

• an air intake system for feeding air to the engine of a vehicle that provides higher transmission loss improvement over the frequency range of the engine operation;

• an air intake system for feeding air to the engine of a vehicle that eliminates the pressure drop problem;

• an air intake system for feeding air to the engine of a vehicle that eliminates the water wading risk;

• an air intake system for feeding air to the engine of a vehicle that has a comparatively lower cost to manufacture; and

• an air intake system for feeding air to the engine of a vehicle that provides the flexibility of being fine-tuned for a specific frequency.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the invention. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the invention as it existed anywhere before the priority date of this application.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the invention, unless there is a statement in the specification specific to the contrary.

While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the invention. These and other changes in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. ,CLAIMS:1. An air intake system for feeding air to the engine of a vehicle, said system comprising:
an expansion chamber mounted inline between the air inlet of the system and the engine, said expansion chamber having a profiled wall defining a cavity having a varying cross section, an inlet and an outlet defined in said wall along parallel axes configured to permit ambient air to enter through said inlet, expand in said chamber and flow in a direction substantially parallel but in opposite direction of the direction of entry of the air into said expansion chamber; and

a conduit fitted between the outlet of said expansion chamber and inlet of said engine, a portion of said conduit distal from said expansion chamber outlet having a varying cross section.

2. The air intake system for feeding air to the engine of a vehicle as claimed in claim 1, wherein the area of said cross section of said cavity decreases as the cavity approaches the inlet and outlet of said expansion chamber.

3. The air intake system for feeding air to the engine of a vehicle as claimed in claim 1, wherein said conduit further consists of at least two pipes, one of said pipes with uniform cross section and another pipe with varying cross section.

4. The air intake system for feeding air to the engine of a vehicle as claimed in claim 1, wherein an air filter system is intermediately connected between said conduit and said engine.

5. The air intake system for feeding air to the engine of a vehicle as claimed in claim 1, wherein said inlet and said outlet are tubular openings of one of cast directly on the surface of said expansion chamber and externally attached to said expansion chamber.

6. The air intake system for feeding air to the engine of a vehicle as claimed in claim 1, wherein said expansion chamber has a ‘C’ shape, wherein one end of said ‘C’ shape constitutes said inlet and other end constitutes said outlet, with length of said outlet is greater than the length of said inlet and other end of said outlet connected to one end of said conduit.

7. The air intake system for feeding air to the engine of a vehicle as claimed in claim 1, wherein shape of said inlet is polygonal and shape of said outlet is elliptical.