[0001] The present disclosure, in general, relates to an air intake structure for a vehicle and, more particularly, to uniform distribution of Exhaust Gas Recirculation (EGR) to a plurality of air intake runners in the air intake manifold structure. The present air intake manifold structure has a EGR gallery to allow mixture of EGR with fresh air in surge tank.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Generally, Exhaust Gas Recirculation (EGR) is added in intake system in diesel engine for NOx reduction by decrease in the peak combustion temperatures.
[0004] In recent days, the EGR in petrol engine is being trend for increasing fuel efficiency by adding the EGR in part load conditions to the intake system thus by decreasing the part load pumping loss.
[0005] An EGR system consist a EGR valve for controlling flow of EGR and a EGR cooler to cool the exhaust gases before adding to intake manifold. Further, the EGR system consist EGR piping to connect the EGR from the exhaust gas pipe to the EGR cooler and from the EGR cooler to the intake manifold. In some cases, there EGR piping connects the EGR valve to the intake manifold. The EGR inlet pipe connects the exhaust pipe to the EGR cooler.

[0006] In an embodiment as shown in fig.la, the arrangement has an intake manifold 100 where the intake manifold has a plurality of air intake runners 1, 2, 3, 4 and a surge tank 101. The plurality of air intakes is connected to the cylinder head 105 to provide mixture of air and fuel. The intake manifold 100 is coupled with EGR system to transfer EGR back to the combustion cylinder. The EGR system has EGR valve 103 for controlling flow of EGR and EGR cooler to cool the exhaust gas. Further, the EGR system has EGR piping that recirculate the EGR back to the intake manifold. As shown in fig. 1, the EGR system has an EGR inlet pipe connects exhaust pipe to the EGR cooler. Further, an EGR outlet pipe connects the EGR cooler to cylinder head gallery. An EGR outlet pipe 102 connects the EGR adapter mounted on the cylinder head gallery to surge tank 101 of the intake manifold 100.
[0007] As shown in the fig. la, the EGR pipe 102 is provided on the same side of the surge tank 101 from where the plurality of air intake runners is extending. In the surge tank 101, the EGR mixes with fresh air coming from throttle 106 (as shown in fig lb) and distributed to each cylinder in the cylinder head 105. The present position and arrangement of the EGR outlet pipe 102 with surge tank 101 do not allow uniform distribution of EGR in between each cylinder. With the present arrangement, the EGR is not properly mixing with fresh air because the fresh air inlet, i.e., throttle inlet 106 is far from the inlet of the EGR in the surge tank 101. Another technical reason for un-even distribution of EGR is that entry of EGR through the EGR outlet pipe 102 is near to air intake runner 3 and 4 as compared to runner 1 and 2.
[0008] With un-even distribution of EGR in each combustion cylinder, ignition timing related calibration problem is generated in the combustion engine. Uneven distribution of EGR results in unstable combustion which affects the combustion quality and hence deteriorates the emission.

[0009] Therefore, there is a need in the art to provide a technical solution that can uniformly distributes EGR among all plurality of air intake runners to improve fuel efficiency.
OBJECTS OF THE DISCLOSURE
[0010] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0011] The principal object of the present invention is to provide an air intake structure for uniform distribution of EGR in all air intake runners.
[0012] Another object of the present invention is to provide a EGR passage structure to open near throttle inlet so that EGR mixes instantly with incoming fresh air and thus equal amounts of the EGR can be distributed to each cylinder through the air intake runners.
[0013] Another object of the present invention is to provide a shortest path to the EGR flow so that there is no pressure drop in the EGR flow.
[0014] Another object of the present invention is to provide the EGR passage structure integrally provided within surge tank of the air intake structure to achieve shortest path for EGR flow.
[0015] These and other objects and advantages will become more apparent when reference is made to the following description and accompanying drawings.
SUMMARY
[0016] This summary is provided to introduce concepts related to an air intake structure for uniform distribution of exhaust gas recirculation (EGR) in plurality of air intake runners. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0017] In an embodiment, the present disclosure relates to an air intake manifold structure for uniform distribution of exhaust gas recirculation (EGR). The air intake manifold structure comprising a surge tank and a plurality of air intake runners extending forwardly from front surface of the surge tank; and a throttle inlet provided at rear surface of the surge tank. The air intake structure has an EGR passage structure provided in the surge tank, the EGR passage structure having an inlet and an outlet, where the outlet of the EGR passage structure intersect with the throttle inlet for mixing of EGR with fresh inlet air.
[0018] In an aspect, the EGR passage structure is integrated with the surge tank.
[0019] In an aspect, the inlet of the EGR passage structure is provided at the front surface and the outlet is intersecting the throttle inlet at the rear surface.
[0020] In an aspect, the EGR passage structure is integrally provided along the front surface, top surface, and rear surface of the surge tank.
[0021] In an aspect, the inlet of the EGR passage structure is connected to an EGR outlet pipe at the front surface.
[0022] In an aspect, the end portion of the outlet of the EGR passage structure is bent in direction of the fresh inlet air from the throttle inlet.
[0023] In an aspect, the EGR passage structure integrally provided by means of plastic molding process.
[0024] In an aspect, the EGR passage structure consist a bottom structure provided in the surge tank that define a passage route from the inlet to the outlet, the passage route passes along the front surface, top surface, and the rear surface of the surge tank, where the passage route along top surface is open; and a top structure connected with the open passage route along the top surface to form a closed EGR passage structure.

[0025] In an aspect, the top structure is connected with the open passage route by means of welding, or by means of nut-bolt with seal (Gasket), adhesive.
[0026] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
[0028] Fig. 1a and 1b illustrate conventional air intake manifold structure with EGR outlet pipe;
[0029] Fig. 2a illustrates air intake manifold structure with an EGR passage structure, in accordance with an embodiment of the present disclosure;
[0030] Fig. 2b illustrates top view of surge tank of air intake manifold of Fig. 2a;
[0031] Fig. 2c illustrates cut section view of surge tank from side of Fig. 2a; and
[0032] Fig. 3 illustrates efficiency results of the present air intake manifold structure with an EGR passage structure of Fig. 2a-2c, in accordance with an embodiment of the present subject disclosure.
[0033] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from
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the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein
DETAILED DESCRIPTION
[0034] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
[0035] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0036] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a",” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, 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.
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[0037] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0038] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0039] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0040] Fig. 2a illustrates an air intake manifold structure 200 for uniform distribution of EGR. The air intake manifold structure 200 comprises a surge tank 201 where fresh air accumulates from environment and goes into combustion cylinder through plurality of air intake runners 1, 2, 3,4. The surge tank 201 is in hollow cuboidal shape structure having front, rear, top, bottom, left side and right side surfaces. The plurality of air intake runners 1, 2, 3,4 is extending forwardly from front surface 201a of the surge tank 201 and a throttle inlet 206 is provided at opposite surface, i.e., rear surface 201b of the surge tank 201.
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[0041] As shown in fig. 2a and 2b, an EGR passage structure 207 having an inlet 207a and an outlet 207b is provided in the surge tank (201). The outlet 207b of the EGR passage structure 207 is in intersection with the throttle inlet 206 of the surge tank 201 for instantly mixing of EGR with fresh inlet air. The inlet 207a of the EGR passage structure 207 is provided at the front surface 201a of the surge tank 201 and the outlet 207b is intersecting with the throttle inlet 206 at the rear surface 201b of the surge tank 201.
[0042] As shown in fig. 2b, the air intake manifold structure 200 can be made of plastic material or metal material. The air intake manifold structure 200 can be made of plastic material by molding process. Further, the air intake manifold structure 200 can be made of metal material by casting process. Accordingly, the EGR passage structure 207 can be provided integrally with the air intake manifold structure 200 by means of molding or casting.
[0043] To form the EGR passage structure 207 in the surge tank 201 of the air intake manifold structure 200 made of plastic material, movement of slider tool is required to make a passage route 207d in the surge tank 201. The slider moves in the front surface 201a of the surge tank 201 to form the inlet 207a and passage route 207d in the front surface 201a. The slider moves on the top surface 201c to form the passage route 207d on the top surface. As seen from the fig. 2b, the passage route 207d is open at the top surface 201c to provide space for movement of the slider in the front surface 201a, the top surface 201c, and the rear surface 201b.
[0044] In the metal air intake manifold structure 200, the EGR passage structure 207 can be provided by means of casting process.
[0045] Referring to fig. 2b and 2c, the EGR passage structure 207 is integrally provided along the front surface 201a, the top surface 201c, and rear surface 201b of the surge tank 201. The inlet 207a of the EGR passage structure 207 is
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connected to an EGR outlet pipe 202 at the front surface 201a of the surge tank 201 to receive the EGR flow and releases the EGR flow at intersection of the outlet 207b and the throttle inlet 206 for mixing of EGR flow with fresh inlet air.
[0046] As shown in fig. 2b and 2c, the EGR passage structure 200 has a bottom structure 207c which is integrated or provided in the surge tank 201 and a top structure 207e that act as a cover to close the bottom structure 207c. The bottom structure 207c define a passage route 207d from the inlet 207a to the outlet 207b. The passage route 207d passes along the front surface 201a, the top surface 202c, and the rear surface 201b of the surge tank 201. The passage route 207d is open along top surface (202c) for movement of the slider to create the passage route 207d in the front surface, top surface and rear surface. The top structure 207e is provided upon the open passage route 207d along the top surface 202c to form a closed EGR passage structure 207.
[0047] The top structure 207e can be permanently sealed with the open passage route 207d by means of adhesive or welding. The top structure 207e can be openably connected with the open passage route 207d by means of snap fitting or bolting mechanism to allow cleaning of the EGR passage structure. In the openable connection, the top structure 207e is connected to the open passage route 207d with proper sealing so that no EGR flow can leak from the connection.
[0048] In an embodiment, end portion of the outlet 207b of the EGR passage structure 207 is bent in direction of the fresh inlet air from the throttle inlet 206 so that to restrict EGR gas flow towards Throttle Body/valve because when EGR gas is condensed it will stick to butterfly valve of Throttle Body and affects its functioning and there is instant mixing of the EGR flow with the fresh inlet air.
[0049] To achieve the shortest path for travelling of EGR flow, the present air intake manifold structure 200 has EGR passage structure 207 through the surge
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tank 201. Further, in the present invention, cool EGR is circulated by the EGR outlet pipe 202 to the EGR passage structure 207 for mixing with fresh inlet air.
[0050] With the present air intake manifold structure, the EGR flow mixes with the fresh inlet air at starting point therefore homogenous mixture of the EGR flow and fresh inlet air is available in the surge tank 201. Further, position of the EGR outlet 207b is at equal distance from all the air intake runners so that equal distribution can be achieved. With the present structure, each air intake manifold receives equal amount of EGR flow along with fresh inlet air.
[0051] Fig. 3 illustrates EGR distribution efficiency results of the present air intake manifold structure with an EGR passage structure. As shown in fig. 3, A002 indicates EGR distribution of the existing structure of the air intake manifold structure with EGR passage structure. The present graph is showing that EGR is highest (for example 50%) at runner 4 where the EGR is located in proximity, runner 3 has less EGR distribution (for example 18%), and runner 1 and runner 2 has least EGR distribution, for example, 4%. On the other hand, A004 indicates EGR distribution of the present air intake structure with the EGR passage structure. As shown in fig. 3, all runners, i.e., runner 1, 2, 3, and 4 have approximately equal distribution of EGR which is approximately 20%.
[0052] With equal distribution of EGR in the air intake manifold structure, stable combustion can be obtained in the combustion engine which affects the combustion quality and improves emissions.
[0053] The term "vehicle" as used throughout this detailed description and in the claims refers to any moving vehicle that is capable of carrying one or more human occupants or goods and is powered by any form of energy. The term "vehicle" is a motor vehicle which includes, but is not limited to: cars, trucks, vans, minivans, hatchback, sedan, MUVs, and SUVs.

[0054] The above description does not provide specific details of the manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art can choose suitable manufacturing and design details.
[0055] Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0056] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0057] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

We claim:

An air intake manifold structure (200) for uniform distribution of exhaust gas recirculation (EGR), the air intake manifold structure (200) comprising:
a surge tank (201);
a plurality of air intake runners (1, 2, 3, 4) extending forwardly from front surface (201a) of the surge tank (201);
a throttle inlet (206) provided at rear surface (201b);
characterized in that
an EGR passage structure (207) having an inlet (207a) and an outlet (207b) provided in the surge tank (201), where the outlet (207b) of the EGR passage structure (207) intersect with the throttle inlet (206) for mixing of EGR with fresh inlet air.
The air intake manifold structure (200) as claimed in claim 1, wherein the EGR passage structure (207) is integrated with the surge tank (201).
The air intake manifold structure (200) as claimed in claim 1, wherein the inlet (207a) of the EGR passage structure (207) is provided at the front surface (201a) and the outlet (207b) is intersecting with the throttle inlet (206) at the rear surface (201b).
The air intake manifold structure (200) as claimed in claim 1, wherein the EGR passage structure (207) is integrally provided along the front surface (201a), top surface (201c), and rear surface (201b) of the surge tank (201).
The air intake manifold structure (200) as claimed in claim 1, wherein the inlet (207a) of the EGR passage structure (207) is connected to an EGR outlet pipe (202).

The air intake manifold structure (200) as claimed in claim 1, wherein the outlet (207b) of the EGR passage structure (207) is bent in direction of the fresh inlet air from the throttle inlet (206).
The air intake manifold structure (200) as claimed in claim 1, wherein the EGR passage structure (207) integrally provided by means of plastic molding process.
The air intake manifold structure (200) as claimed in claim 1, wherein the EGR passage structure (207) comprising:
a bottom structure (207c) provided in the surge tank (201) that define a passage route (207d) from the inlet (207a) to the outlet (207b), the passage route (207d) passes along the front surface (201a), top surface (202c), and the rear surface (201b) of the surge tank (201), where the passage route (207d) along top surface (202c) is open; and
a top structure (207e) connected with the open passage route (207d) along the top surface (202c) to form a closed EGR passage structure (207).
The air intake manifold structure (200) as claimed in claim 8, wherein the top structure (207e) is connected with the open passage route (207d) by means of welding, nut-bolt with seal, adhesive.