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Paramétrages

Paramétrages

1. EP3146174 - SYSTÈME DE TRAITEMENT DES GAZ D'ÉCHAPPEMENT D'UN VÉHICULE ÉQUIPÉ D'UN MOTEUR À COMBUSTION INTERNE

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique
Description


[0001]  The present invention refers to a system for treating exhaust gases for a vehicle equipped with internal combustion engine, in particular but not exclusively a farming or industrial tractor equipped with a forced induction diesel cycle engine.

[0002]  Similarly to automobiles and trucks, also in farming and industrial tractors it is known to use systems for treating exhaust gases of the DOC ("Diesel Oxidation Catalyst"), DOC + POC ("Particulate Oxidation Catalyst") or DPF ("Diesel Particulate Filter") type. In particular, in farming and industrial tractors the system for treating the exhaust gases is usually mounted at the engine, typically under the hood over such an engine. For example, some systems for treating exhaust gases for farming and industrial tractors of the known type are described in documents EP-A-1947305, EP-A-2379856, EP-A-2379857, EP-A-2440758 and GB-A-2465151. Other known systems for treating exhaust gases, not necessarily used on farming and industrial tractors, on the other hand, are described in documents JP-A-2012072722, US-A-6106344, JP-A-2012219624, US-B-6651773 and DE-A-19955013.

[0003]  A drawback of current systems for treating exhaust gases for farming and industrial tractors is due to their size. This sometimes means that the hood and/or other parts of the bodywork of the vehicle have to be changed in order to be able to correctly house both the system for treating exhaust gases, and the relative connection conduits with the engine.

[0004]  The purpose of the present invention is therefore to provide a system for treating exhaust gases for a vehicle equipped with internal combustion engine, in particular but not exclusively a farming or industrial tractor equipped with a forced induction diesel cycle engine, which is able to overcome the aforementioned drawbacks of the prior art in an extremely simple, cost-effective and particularly functional manner.

[0005]  In detail, a purpose of the present invention is to provide a system for treating the exhaust gases for a vehicle equipped with internal combustion engine that is of a particularly small size, so as to be able to be easily installed in the engine compartment of the vehicle without the need to make any modifications. The system for treating the exhaust gases according to the present invention comprises both a device actually intended for treating exhaust gases, configured to reduce the polluting emissions below the limits prescribed by the current technical legislation, and the suitable means for connecting the device itself with the engine on one side and with the silencer, or with a further device for treating the exhaust gases, on the other side. These devices can consist of DOC or DOC + POC type catalysts, or of DPF type filters.

[0006]  The system for treating the exhaust gases according to the present invention is designed to be arranged under the hood of the vehicle, above the engine. The system is fed by the exhaust gases coming out from the turbine of the engine, which is indeed of the forced induction type. These gases go through the system and, thereafter, are conveyed outside of the vehicle through a suitable exhaust piping.

[0007]  The system is applicable in particular to those engine configurations in which the outlet of the turbine is on the fly-wheel side. The system has a compact, oval shape, such as to occupy the least height-wise space possible and ensure the use of the existing hoods. The system also has the purpose of reducing to the minimum the length of the conduits for connecting between the filter and the air radiator with the compressor, as well as of the connection conduits downstream of the turbine. This arrangement finally achieves the purpose of improving the distribution of the thermal loads in the area beneath the hood of the vehicle.

[0008]  These purposes according to the present invention are accomplished by making a system for treating the exhaust gases for a vehicle with internal combustion engine, in particular but not exclusively a farming or industrial tractor equipped with a diesel cycle engine, as outlined in claim 1.

[0009]  Further characteristics of the invention are highlighted by the dependent claims, which are an integral part of the present description.

[0010]  The characteristics and advantages of a system for treating exhaust gases for a vehicle equipped with internal combustion engine according to the present invention will become clearer from the following description, given as an example and not for limiting purposes, referring to the attached schematic drawings, in which:

figure 1 shows a generic farming tractor on which a system for treating exhaust gases according to the present invention is installed;

figure 2 is a schematic side view of the engine compartment of the farming tractor of figure 1, in which the arrangement of the system for treating exhaust gases according to the present invention is illustrated;

figure 3 is a perspective view of the system for treating exhaust gases according to the present invention;

figure 4 shows the layout of the system for treating exhaust gases according to the present invention;

figures 5 and 6 respectively show the layouts of two systems for treating exhaust gases for farming and industrial tractors according to the prior art;

figure 7 is a section view of the system for treating exhaust gases according to the present invention, in which the direction of flow of the exhaust gases is highlighted;

figure 8 shows an internal combustion engine, in particular a diesel cycle engine, provided with a forced induction group with turbocompressor, on which a system for treating exhaust gases according to the present invention is installed;

figure 9 is a partial side view of the internal combustion engine of figure 8; and

figure 10 is a partial view from above of the internal combustion engine of figure 8.



[0011]  With reference to the figures, a system for treating exhaust gases according to the present invention is shown, wholly indicated with reference numeral 10. The system 10 for treating exhaust gases is configured to be mounted on a vehicle 12 consisting of a generic farming or industrial tractor provided with an internal combustion engine 14 of the diesel cycle type and with a forced induction group with turbocompressor. The engine 14 is enclosed by a hood 16, a part of which has been cut out in figure 1 for the sake of clarity.

[0012]  The system 10 for treating exhaust gases is provided with a conduit 18 for the inlet of exhaust gases, operatively connected to the exit door of the turbine 22 of the engine 14. The turbine 22 is placed on the same side as the fly-wheel 24 of the engine 14. The system 10 for treating exhaust gases is also provided with a conduit 20 for the outlet of exhaust gases (figure 3), operatively connected to the piping 26 that contains the silencer and that discharges the treated smoke towards the outside.

[0013]  With reference to figure 2, which shows the engine compartment of the tractor 12, the arrangement of the components of the engine 14 is illustrated. The cooling system 28 of the tractor 12 is placed at the front part with respect to the engine 14 (on the left in figure 2), whereas the fly-wheel 24 is placed at the rear part with respect to the engine 14 (on the right side of figure 2). Above the engine 14, the forced induction group is housed, consisting of a compressor 30 and of the turbine 22. The exit door of such a turbine 22 is connected to the system 10 for treating the exhaust gases through the conduit 18 for the inlet of exhaust gases, thermally insulated with respect to the engine 14. The compressor 30 is installed upstream of the turbine 22 so as to avoid, considering the flow of air discharged by the fan 54 of the tractor 12, a further increase of its temperature, as well as of the temperature of the air that passes through it.

[0014]  Figure 3 illustrates the system 10 for treating exhaust gases according to the present invention. The conduit 18 for the inlet of exhaust gases, thermally insulated with respect to the engine 14, consists in sequence of a flange 32 for coupling to the exit door of the turbine 22, a first pipe 34 with a 90° elbow curve, a flexible element 36, configured for absorbing the heat dilations and mechanical vibrations, and a second pipe 40 with a 90° elbow curve, which allows the removable coupling of the conduit 18 for the inlet of exhaust gases with the main body or shell 38 of the system 10 for treating the exhaust gases. Based on this configuration the conduit 18 for the inlet of exhaust gases assumes a substantially U shape and is able to deviate the flow of such exhaust gases by about 180°.

[0015]  The conduit 18 for the inlet of exhaust gases and the conduit 20 for the outlet of exhaust gases are placed in fluid communication with a same transverse side wall 46, with respect to the driving direction of the vehicle 12, of the main body or shell 38 of the system 10 for treating exhaust gases. In detail, formed on such a transverse side wall 46 of the main body or shell 38 are an inlet fitting 62, able to be connected to the second pipe 40 with a 90° elbow curve of the conduit 18 for the inlet of exhaust gases through a coupling device 42 of the " V-clamp" type, as well as the conduit 20 for the outlet of exhaust gases, able to be connected to the exhaust piping 26 of the engine 14 through known coupling means. The main body or shell 38 of the system 10 for treating the exhaust gases is internally hollow to contain the substrate 44 (catalyst or filter, figure 7) through which the exhaust gases are conveyed, as will be specified in greater detail hereafter.

[0016]  Figure 4 schematically shows the arrangement of the components of the system 10 for treating the exhaust gases according to the present invention with respect to the components of the engine 14. This arrangement can be compared with the known solutions of figure 5 and figure 6. The forced induction system, consisting of the compressor 30 and the turbine 22, is arranged with the compressor 30 on the side of the cooling system 28 in figure 4 and in figure 5, and on the side of the fly-wheel 24 in figure 6. The air intake conduit 48 of the engine 14 connects the air filter 50 with the compressor 30.

[0017]  The system 10 for treating exhaust gases is connected to the exit door of the turbine 22 through the conduit 18 for the inlet of exhaust gases. The system 10 for treating exhaust gases is also connected to the exhaust piping 26, or to a further system 52 for the treatment of exhaust gases, through the conduit 20 for the outlet of exhaust gases. It should be noted that in the configuration according to the present invention (figure 4) there is an improvement in terms of transverse overall dimension (width a) and longitudinal dimension (length b) of the system 10 for treating exhaust gases with respect to known configurations (figures 5 and 6).

[0018]  The system 10 for treating exhaust gases according to the present invention makes it possible to simultaneously obtain a shorter length of the air intake conduit 48 of the engine 14, of the conduit 18 for the inlet of exhaust gases, which connects the turbine 22 with the system 10 for treating exhaust gases, and of the exhaust piping 26, ensuring the following advantages:
  • a reduced load loss in the air intake conduit 48 and in the exhaust piping 26 and therefore better performance of the engine 14 during the transient work cycle;
  • the shorter length of the air intake conduit 48 allows a reduction of the heat transferred from the hot air, discharged by the fan 54, to the cool air contained inside the air intake conduit 48 itself;
  • the shorter length of the exhaust piping 26 allows a reduction of the heat transferred from the exhaust gases, contained in the exhaust piping 26 itself, to the outside. The higher the temperature of the exhaust gases, the better the efficiency of the system 10 for treating exhaust gases.


[0019]  Figure 7 is a section view of the system 10 for treating exhaust gases according to the present invention. The fumes exiting from the conduit 18 for the inlet of exhaust gases are expanded and slowed down in a divergent conduit 56 enclosed by the main body or shell 38 and arranged between such a conduit 18 for the inlet of exhaust gases and the substrate 44, thus coming into contact with the substrate 44 itself. The residency time of the exhaust gases inside the substrate 44 must be sufficient to complete the chemical reactions.

[0020]  Once the substrate 44 has been passed, the fumes undergo a deviation of 180° towards the conduit 20 for the outlet of exhaust gases by an end wall 58 of the main body or shell 38 opposite with respect to the transverse side wall 46 on which both the inlet conduit 18, and the conduit 20 for the outlet of exhaust gases are formed. The flow is indicated by the arrows present in figure 7.

[0021]  The fumes lap the outer walls of the main body or shell 38 with the purpose of keeping the temperature of the substrate 44 as much as possible at a constant value and of helping the heating step of the system 10 for treating exhaust gases, reducing the time needed to reach the activation temperature of the catalyst. The outer surface of the main body or shell 38 is thus at least partially coated with a layer 60 of heat insulating material, which also covers the end wall 58 for deviating the exhaust gases.

[0022]  Figure 8 shows the arrangement of the system 10 for treating the exhaust gases according to the present invention on the head of the engine 14. In figure 8 it can also be seen how the main body or shell 38 of the system 10 for treating exhaust gases has a cross-sectional shape, with respect to the driving direction of the vehicle 12, of an ellipsoid the larger axis of which is oriented according to a substantially horizontal direction and the smaller axis of which is oriented according to a substantially vertical direction. In other words, the main body or shell 38 of the system 10 for treating exhaust gases has a widened and compressed shape, with oval or ellipsoidal cross section, which allows it to occupy the least possible height-wise space on the head of the engine 14.

[0023]  In detail, with reference to figures 9 and 10, D RIF indicates the diameter of the inlet door of the compressor 30, whereas X indicates a longitudinal reference axis passing through the centre of the inlet door of the compressor 30. With respect to the diameter D RIF and to the longitudinal reference axis X, the main overall dimensions of the system 10 for treating exhaust gases are as follows:

where:
  • A = maximum overall height of the system 10 for treating exhaust gases;
  • B = transverse overall dimension of the system 10 for treating exhaust gases on the right side with respect to the longitudinal reference axis X;
  • C = transverse overall dimension of the system 10 for treating exhaust gases on the left side with respect to the longitudinal reference axis X.


[0024]  It has thus been seen that the system for treating exhaust gases for a vehicle equipped with internal combustion engine according to the present invention achieves the purposes outlined earlier.

[0025]  The system for treating exhaust gases for a vehicle equipped with internal combustion engine of the present invention thus conceived can in any case undergo numerous modifications and variants, all of which are covered by the same inventive concept; moreover, all of the details can be replaced with technically equivalent elements. In practice, the materials used, as well as the shapes and sizes, can be whatever according to the technical requirements.

[0026]  The scope of protection of the invention is therefore defined by the attached claims.