FR3054611A1 - PLATE FOR MIXING A RECIRCULATED EXHAUST GAS FLOW WITH AN INTAKE GAS FLOW FOR A THERMAL ENGINE - Google Patents

Abstract

The invention relates mainly to a heat engine (9), especially a motor vehicle, said engine (9) comprising: - a cylinder head (22) having a plurality of intake valve passages in communication with cylinders of said engine (9), - an inlet distributor (20) for supplying air to said cylinders via air ducts, - an exhaust redirection duct (12) adapted to redirect a portion of the exhaust gases. exhaust from an exhaust manifold to said intake manifold (20), characterized in that said heat engine (9) further comprises a mixing plate (10) into which said gas redirection pipe (10) exhaust (12), said mixing plate (10) being interposed between said intake manifold (20) and said cylinder head (22) and configured to distribute said recirculated exhaust gas into each of said manifold air ducts; inlet (20) in communication with a corresponding cylinder.

Description

Holder (s): PEUGEOT CITROEN AUTOMOBILES SA Société anonyme.

Extension request (s)

Agent (s): PEUGEOT CITROEN AUTOMOBILES SA Public limited company.

PLATE FOR MIXING A RECIRCULATED EXHAUST GAS STREAM WITH AN INTAKE GAS STREAM FOR A THERMAL ENGINE.

FR 3 054 611 - A1 (£ /) The invention relates mainly to a heat engine (9), in particular for a motor vehicle, said heat engine (9) comprising:

a cylinder head (22) comprising a plurality of intake valve passages in communication with cylinders of said heat engine (9),

- an inlet distributor (20) capable of supplying air to said cylinders via air lines,

- an exhaust gas redirection pipe (12) capable of redirecting part of the exhaust gases from an exhaust manifold to said intake distributor (20), characterized in that said heat engine (9 ) further comprises a mixing plate (10) into which opens said exhaust gas redirection pipe (12), said mixing plate (10) being interposed between said intake distributor (20) and said cylinder head (22 ) and configured to distribute said recirculated exhaust gases in each of the air pipes of said intake distributor (20) in communication with a corresponding cylinder.

PLATE FOR MIXING A FLOW OF RECIRCULATED EXHAUST GAS WITH A FLOW OF INTAKE GAS FOR AN ENGINE The present invention relates to a plate for mixing a flow of exhaust gas recirculated with a flow of intake gas for heat engine. The invention finds a particularly advantageous, but not exclusive, application in the field of motor vehicles.

In a heat engine, the four stages of the thermodynamic cycle admission of combustible gas and air, compression of the gas mixture, expansion due to the explosion of the mixture, exhaust - take place successively in the chambers of the engine cylinders, say combustion chambers. The gases introduced into these combustion chambers consist on the one hand of air and on the other hand of gasoline or diesel oil, in proportions dosed adequately according to the engines and the ignition systems used. The gas mixture is then ignited in the combustion chamber.

The exhaust gases from heat engines fitted to most motor vehicles contain a certain number of pollutants, the discharge into the atmosphere of which it is desirable to reduce (in particular nitrogen oxides, carbon monoxide, hydrocarbons unburnt, particles and carbon dioxide). The applicable regulations on pollution from motor vehicles regularly lower the acceptable discharge ceilings.

A large part of the pollutants generated by a heat engine is due to incomplete combustion of the fuel. To reduce the discharge of pollutants entering the exhaust line, it is known to use a system called EGR (acronym for Exhaust Gas Recirculation in English) to recirculate part of the exhaust gas to the intake pipe of the heat engine.

To this end, the EGR system includes an exhaust gas redirection pipe capable of redirecting part of the exhaust gases from the exhaust manifold to the engine intake after passing through a heat exchanger. An EGR valve makes it possible to manage the quantity of exhaust gas reinjected at the intake. However, EGR systems can significantly increase the amount of smoke in the exhaust gases in the event of an uneven distribution at the intake.

The invention aims to effectively remedy this drawback by proposing a heat engine, in particular for a motor vehicle, the heat engine comprising:

a cylinder head comprising a plurality of passages of intake valves in communication with cylinders of the heat engine,

- a gas intake distributor capable of supplying air to the cylinders via air lines,

- an exhaust gas redirection pipe capable of redirecting part of the exhaust gases from an exhaust manifold to the intake manifold, characterized in that the heat engine also comprises a mixing plate in which opens the exhaust gas redirection pipe, the mixing plate being interposed between the intake distributor and the cylinder head and configured to distribute the recirculated exhaust gases in each of the air pipes of the intake distributor communication with a corresponding cylinder.

The invention thus allows a homogeneous distribution of the recirculated exhaust gases at the intake while facilitating the integration of the plate because of its compact nature. The invention also makes it possible to avoid the effects linked to the combustion of the deposits of the recirculated exhaust gases.

According to one embodiment, the mixing plate comprises:

a main pipe connected by one of its ends to the exhaust gas redirection pipe, and

- distribution pipes each opening into a through opening in communication on the one hand with an air duct of the intake distributor and on the other hand with a corresponding cylinder.

In one embodiment, the distribution pipes are inclined relative to a plane normal to the axes of the through openings.

In one embodiment, an angle of inclination between the distribution pipes and the plane normal to the axes of the through openings is between 15 degrees and 30 degrees.

In one embodiment, the diameters of the distribution pipes decrease when moving away from an inlet of the exhaust gas from the mixing plate.

According to one embodiment, the diameters of the distribution pipes are between 5 mm and 15 mm.

According to one embodiment, a diameter of the main pipe is between 10mm and 15mm.

According to one embodiment, the mixing plate includes tight plugs to close one end of manufacturing bores made to form the various pipes.

In one embodiment, the mixing plate is made of an aluminum-based material.

The invention also relates to a motor vehicle comprising a heat engine as defined above.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given only by way of illustration but in no way limit the invention.

Figure 1 is a perspective view of an exhaust gas recirculation system incorporating the mixing plate according to the present invention;

Figure 2 is a perspective view in longitudinal section of the mixing plate according to the present invention illustrating the pipes opening out inside the air pipes of the intake manifold;

Figure 3 is a detailed perspective view of the mixing plate according to the present invention;

Figure 4 is a side view in section of the mixing plate according to the present invention illustrating the passage of recirculated exhaust gases to the intake channels of the engine;

Figure 5 is a side view in section of the mixing plate according to the present invention illustrating the angular orientation of the distribution pipes with respect to the direction of circulation of the inlet gases.

Identical, similar, or analogous elements retain the same reference from one figure to another.

Figure 1 shows a mixing plate 10 into which opens the redirection pipe 12 of the exhaust gas from an exhaust gas recirculation system 14 (called EGR for Exhaust Gas Recirculation in English). This pipe 12 comes from a heat exchanger 16. The quantity of exhaust gas recirculated is controlled by the valve 18, called the EGR valve.

The mixing plate 10 is interposed between the intake distributor 20 supplying air to the cylinders and the cylinder head 22 of the heat engine 9 comprising a plurality of passages 24 of intake valves in communication with the cylinders of the engine 9. The air inlet of the intake distributor 20 is referenced 26 in FIG. 1.

The mixing plate 10 is configured to distribute the recirculated exhaust gases in each of the air lines 28 of the intake manifold 20 in communication with a corresponding cylinder.

To this end, as illustrated in Figure 2, the mixing plate 10 comprises a main pipe 30 connected by one of its ends to the redirection pipe 12 of the exhaust gases in communication with the manifold exhaust. The mixing plate 10 also comprises distribution pipes 32 each opening into a through opening 34 in communication on the one hand with an air pipe 28 of the intake distributor 20 and on the other hand with a corresponding cylinder via a passage valve 24.

In this case, the main pipe 30 is formed in an upper portion 101 of the plate 10 while the through openings 34 are formed in a lower portion 102 which is mounted clamped between the cylinder head 22 and the intake manifold 20. The distribution pipes 32 are produced in an intermediate portion 103 of the plate 10 extending between the upper portion 101 and the lower portion 102. The distribution pipes 32 each open out on the one hand into the main pipe 30 and d on the other hand in the corresponding through opening 34.

In the embodiment shown, the main pipe extends transversely to a direction G of the exhaust gas flow.

Furthermore, as can be seen in Figures 4 and 5, the distribution pipes 32 are inclined relative to a plane P normal to the axes X of the through openings 34, or in the direction G of the exhaust gas circulation at the mixing zone. This makes it possible to promote a homogeneous mixture of the intake gases with the recirculated exhaust gases. In an exemplary embodiment, the angle of inclination A between the distribution pipes 32 and the plane P normal to the axes X of the through openings 34 may for example be between 15 degrees and 30 degrees.

Preferably, the diameters D1 of the distribution pipes 32 decrease when one moves away from an inlet 36 of the exhaust gases from the mixing plate 10. This inlet 36 is produced in a portion of bent pipe with respect to the main pipe 30 to facilitate interconnection with the redirection pipe outlet 12. In a particular embodiment, the diameters D1 may for example be between 5 mm and 15 mm. The diameter D2 of the main pipe 30 may for example be between 10 mm and 15 mm.

In a particular embodiment, the mixing plate 10 may include distribution pipes 32 having respectively a diameter D1 worth approximately 10.8 mm, 9.8 mm, and 9.4 mm when moving away from the inlet 36 of the mixing plate 10. The distribution pipes 32 are inclined at an angle A of the order of 30 degrees. The main pipe 30 has a diameter D2 equal to about 15 mm. The above values are indicated at more or less 10% of the indicated value.

The through opening 34 may have a frustoconical shape as shown in Figure 5. The shape of the pipes 30, 32 and the openings 34 can of course be adapted according to the application.

Preferably, tight plugs 40, 40 'allow to close one end of the manufacturing bores made to form the various pipes. Thus, the plugs 40 close the ends of the bore produced to form the main pipe 30 and the plugs 40 ′ close the ends of the bores opening outwards and produced to form the distribution pipes 32.

Advantageously, the mixing plate 10 is made of an aluminum-based material to avoid the effects associated with the combustion of deposits of recirculated exhaust gases.

Claims (10)

1. Heat engine (9), in particular of a motor vehicle, said heat engine (9) comprising: a cylinder head (22) comprising a plurality of passages (24) of intake valves in communication with cylinders of said heat engine (9), a gas inlet distributor (20) capable of supplying air to said cylinders via air lines (28), - an exhaust gas redirection pipe (12) capable of redirecting part of the exhaust gases from an exhaust manifold to said intake distributor (20), characterized in that said heat engine (9 ) further comprises a mixing plate (10) into which opens said exhaust gas redirection pipe (12), said mixing plate (10) being interposed between said intake distributor (20) and said cylinder head (22 ) and configured to distribute said recirculated exhaust gases in each of said air ducts (28) of said intake distributor (20) in communication with a corresponding cylinder. 2. Heat engine according to claim 1, characterized in that said mixing plate (10) comprises: a main pipe (30) connected by one of its ends to said exhaust gas redirection pipe (12), and - distribution pipes (32) each opening into a through opening (34) in communication on the one hand with an air pipe (28) of said intake distributor (20) and on the other hand with a corresponding cylinder. 3. A thermal engine according to claim 2, characterized in that said distribution pipes (32) are inclined relative to a plane (P) normal to axes (X) of said through openings (34). 4. A thermal engine according to claim 3, characterized in that an angle of inclination (A) between said distribution pipes (32) and said plane (P) normal to the axes (X) of said through openings (34) is included between 15 degrees and 30 degrees. 5. Heat engine according to any one of claims 2 to 4, characterized in that the diameters (D1) of said distribution pipes (32) decrease when moving away from an inlet (36) of the gases exhaust of said mixing plate (10). 6. Heat engine according to claim 5, characterized in that said diameters 5 (D1) of said distribution pipes (32) are between 5 mm and 15 mm. 7. A heat engine according to any one of claims 2 to 6, characterized in that a diameter (D2) of said main pipe (30) is between 10mm and 15mm. 8. A heat engine according to any one of claims 2 to 7, characterized in that said mixing plate (10) comprises tight plugs (40, 40 ') to close one end of manufacturing bores made to form the different lines (30, 32). 9. Heat engine according to any one of claims 1 to 8, characterized in that said mixing plate (10) is made of a base material 15 of aluminum. 10. Motor vehicle characterized in that it comprises a heat engine (9) as defined according to any one of the preceding claims. 2/3 Fig. 4 3/3