FORM - 2
THE PATENTS ACT, 1970
(39 OF 1970)
AND
THE PATENTS RULES, 2003
"COMPLETE SPECIFICATION"
(SEE SECTION 10; RULE 13)
"INTAKE MANIFOLD WITH EGR MIXING DEVICE FOR AUTOMOBILE
ENGINES"
MAHINDRA & MAHINDRA LIMITED
AN INDIAN COMPANY,
R&D CENTER, AUTOMOTIVE SECTOR,
89, M.I.D.C, SATPUR,
NASHIK-422 007,
MAHARASHTRA, INDIA
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES AND ASCERTAINS THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE INVENTION:-
The present invention is related to the re-circulated exhaust gas mixing device in automobile engines. More particularly, the present invention is related to the intake manifold of an automobile engine integrated with re-circulated exhaust gas mixing device.
BACKGROUND OF THE PRESENT INVENTION:-
In diesei internal combustion engine, when combustion of diesel takes place in excess of oxygen very high temperatures are reached in combustion chamber and lot of NOx is generated. To avoid this some non-reactive gas has to be introduced in air which will dilute availability of oxygen preventing high temperature in combustion chamber and thereby generation of NOx. Generally used non-reactive gas is exhaust gases available in the engine.
Exhaust gases are mixed with air intake manifold or upstream of intake manifold. One problem here is that mixing of exhaust gas with air is not uniform which results in uneven distribution of exhaust gases in each cylinder in multi-cylinder engine. Hence, a long mixing length is required upstream of intake manifold.
Another problem in case of turbo-charged engine is under certain operating conditions, the pressure in air passage is more than pressure in exhaust passage which prevents mixing of exhaust gases with air. The present invention is intended to address both the problems mentioned above.
OBJECTIVES OF THE PRESENT INVENTION:-
The main object of the present invention is to provide intake manifold system that achieves improved mixing of exhaust gases with the air.
Another object of the present invention is to provide intake manifold system that makes uniform distribution of EGR to each cylinder of an engine.

Another object of the present invention is to provide compact intake manifold system with EGR mixing device.
STATEMENT OF THE INVENTION:-
Accordingly invention provides an intake manifold with EGR mixing device for automobile engines comprises an intake manifold of engine block connected a first pipe to a turbo-charger run by the exhaust gas of the engine to receive fresh air through a venturi with throat section passage; an exhaust manifold of the said engine connected to said intake manifold venturi throat section passage by a second pipe to re-circulate partially exhaust gas into the said fresh air through an involute passage with direction flow at 90° to the said flow of fresh air; and the out let of the said involute passage made tangential to the said venturi throat section passage throat section.
Accordingly invention also prides an EGR mixing device in the said intake manifold consists a venturi passage provided with cavity at 90° to the said venturi flow passage to receive a throat section formed in an involute passage unit at out let to a tangential circular opening at 90° to the said involute passage.
DESCRIPTION OF THE FIGURES:-
Figure 1 shows schematic representation of typical turbocharged diesel engine.
Figure 2 shows axial cross section of intake pipe integrated with the mixing device in accordance with the present invention.
Figure 3 shows cross section of the intake pipe across the throat.

DETAILED DESCRIPTION OF THE PRESENT INVENTION:-
The present invention is related to mixing of exhaust gases with fresh air. It consists of two passages. Through once passage air flows and through another passage exhaust gases flow. The exhaust passage is involute in shape so that exhaust gases are introduced in air passage tangentially and almost all around the circumference of air passage. The air passage has venturi construction and exhaust gases mix with air at the throat of the venturi. The air passage downstream of the throat carries mixture of air and exhaust gas. Exhaust gases enter tangentially through an involute. In addition to involute mixer, venturi construction is provided.
Referring to figure 1, typical turbocharged diesel engine comprises of block (1), intake manifold (2) and exhaust manifold (3). The turbo-charger (4) is mounted on the exhaust manifold. An intake pipe (5) runs from turbocharger to intake manifold. The exhaust gases are routed back to engine through EGR (exhaust gas recirculation) pipe (6). The exhaust gases mix with fresh air at point (7).
The exhaust gases after combustion comes out of exhaust manifold and enters into turbocharger and comes out of the turbocharger through exhaust system (8). Fresh air comes from air filter (9) and enters into turbocharger. The pressurized air from turbocharger to the intake manifold passes through intake pipe. Some amount of exhaust gases is mixed with fresh air through EGR Pipe-As shown in figure 2, intake pipe with air passage (11) and exhaust gas passage (10), the direction of flow of air (13) and exhaust gases (14) is at 90 degrees to each other. The air passage includes the venturi with throat section (12). As shown in figure 3, the exhaust gas passage (10) is involute in shape. The exhaust gases enter tangentially and flow around the air passage (11) and the mixing takes place at throat section (12) achieving the uniform mixing of exhaust gases with fresh air. Since the air pressure at throat is less than exhaust gas pressure it facilitates the homogeneous mixing of the exhaust

gases with the air stream inside the intake manifold. The venturi construction of this invention ensures air pressure to be always less than exhaust gas pressure. Due to this feature, exhaust gas can be recirculated over a wide range of engine operating conditions.
The EGR mixing device is made two part. The first part intake manifold consists a venturi passage provided with cavity at 90 ° to the said venturi flow passage to receive a throat section. The second part an involute passage unit provided with an out let to a tangential circular opening at 90° to the said involute passage. The involute unit is fixed in the said cavity to make EGR mixing unit according invention.
EGR mixing unit may be fabricated or produced casting/ moulding integrated or in two parts.
ADVANTAGES OF THE PRESENT INVENTION:-
• Improved mixing of exhaust gases with air
• Improvement of uniformity index upto 0.988, hence uniform distribution of EGR to each cylinder
• Mixing length reduced, and hence length of intake pipe is short which helps in packaging.
• Operating range of engine with EGR increased.

WE CLAIM:-
1. An intake manifold with EGR mixing device for automobile engines comprises an intake manifold of engine block connected a first pipe to a turbo-charger run by the exhaust gas of the engine to receive fresh air through a venturi with throat section passage; an exhaust manifold of the said engine connected to said intake manifold venturi throat section passage by a second pipe to re-circulate partially exhaust gas into the said fresh air through an involute passage with direction flow at 90° to the said flow of fresh air; and the out let of the said involute passage made tangential to the said venturi throat section passage throat section.
2. An intake manifold with EGR mixing device as claimed in claim 1 wherein the said EGR mixing device in the said intake manifold consists a venturi passage provided with cavity at 90 ° to the said venturi flow passage to receive a throat section formed in an involute passage unit at outlet to a tangential circular opening at 90° to the said involute passage.
3. An intake manifold with EGR mixing device as claimed in claims 1 and 2 wherein the said intake manifold venturi passage unit and involute passage unit made separately and assembled.
4. An intake manifold with EGR mixing device as claimed in claims 1 and 2 wherein the said intake manifold venturi passage and involute passage made by casting integrated one unit.
5. An intake manifold with EGR mixing device as claimed in claims 1 and 2 wherein the said intake manifold venturi passage and involute passage

made casting two parts divided at throat section and joined together with sealing by fixtures.