FR2969215A1 - Gas distribution manifold for use in gas inlet module for introducing air-fuel mixture into cylinder head of heat engine for vehicle, has protection unit protecting measuring sensor from recirculated exhaust gas flow of engine - Google Patents

Abstract

The manifold (4) has a manifold housing (8) circulating air-fuel mixture flow (G). Internal volume (V) is defined by the housing to receive the air-fuel mixture flow and recirculated exhaust gas flow of a heat engine. A measuring sensor (13) i.e. temperature sensor, is received in the housing for measuring parameter i.e. temperature, of the air-fuel mixtures. The housing comprises a protection unit (15) that protects the measuring sensor from the recirculated exhaust gas flow. The protection unit is formed as a tubular channel that receives a portion (13I) of the measuring sensor. An independent claim is also included for a gas inlet module for a cylinder head of a heat engine of a vehicle, comprising a heat exchanger.

Description

Gas distribution manifold in the cylinder head of an engine

The invention relates to the field of heat exchangers and more particularly to heat exchangers used in the automotive field.

A motor vehicle engine has a combustion chamber, generally formed by a plurality of cylinders, in which a mixture of oxidant and fuel is burned to generate the engine work. The gases admitted into the combustion chamber are called intake gases.

In some cases, these intake gases must be cooled before being introduced into the combustion chamber. This function is fulfilled by a heat exchanger, which is a cooler.

Typically, a heat exchanger comprises a heat exchange bundle formed by a plurality of exchange elements stacked between two end plates (bottom plate and top plate). The spaces between the beam exchange elements form channels for driving a flow of gas to be cooled, here intake gases. The beam exchange elements are hollow and conduct a heat transfer fluid for exchanging heat with the flow of gas to be cooled circulating in the fluid conduit channels for cooling.

In order to reduce the emissions of gaseous pollutants, it is also known to introduce "recirculated" exhaust gases into the intake gas flow. This is exhaust gas taken downstream of the combustion chamber to be re-routed (recirculated) to the intake gas flow, upstream of the combustion chamber, where they are mixed with the inlet gases. view of their admission into the combustion chamber. The recirculated exhaust gas is introduced into a gas inlet pipe extending between the inlet gas cooler and the engine so that the recirculated exhaust gas mixes with the gases from the cooler.

In order to lower the fuel consumption of the engines (and therefore their emission of polluting gases), it is necessary to control the temperature of the intake gases supplying the intake valves of the engines, and more particularly the temperature of the gases of the engine. inlet outlet of the heat exchanger.

For this, it has been envisaged to provide the intake modules for introducing the intake gas into the cylinder head of the heat engines, a temperature sensor mounted in a distribution manifold of the module.

According to one possible solution, there is thus provided a manifold having an internal mixing volume delimited by a collector housing and intended to receive an intake gas flow (cooled by the heat exchanger) and a gas flow of recirculated engine exhaust, the temperature sensor being implanted in this mixing volume.

A disadvantage of such a solution is that the sensor may be in contact with the recirculated exhaust gas.

In this case, the recirculated exhaust gas would, over time, foul the gas temperature sensor, which would affect the quality of the measurements of the latter. As the fouling of the sensor is random, the measurement errors would be as well.

Thus, because of their randomness, the measurement errors of the sensor could not be taken into account by the temperature control computers associated with the motors. The gas supply engines would evolve over time and cause undesirable and uncontrolled variations in fuel consumption and therefore the emission of gaseous pollutants, during the life of the engines.

The object of the present invention is to remedy these drawbacks and, in particular, to allow a reliable measurement of a parameter of the inlet gases (for example the temperature) throughout the life of a heat engine.

For this purpose, according to the invention, the gas distribution manifold in the cylinder head of a vehicle engine, the manifold comprising: a collector housing allowing the circulation of a flow of intake gas, and an internal mixing volume delimited by the collector housing and intended to receive the flow of intake gas and an exhaust gas flow recirculated from the engine, is remarkable in that: said collector housing is configured for receiving at least one measuring sensor, external to the collector, capable of measuring a parameter of the intake gases; and the collector comprises means for protecting the measuring sensor from the recirculated exhaust gas stream.

Thus, thanks to the invention, the quality of the measurements made by the measuring sensor, protected from the flow of gas recirculated by the protection means, is kept stable throughout the life of the engine, which prevents any undesirable variation. the fuel consumption of the engine and therefore its emission of gaseous pollutants (especially when the sensor is a temperature sensor). In particular, the protection means of the measuring sensor prevent its fouling by the flow of recirculated exhaust gas introduced into the internal mixing volume of the distribution manifold.

The collector housing comprises, for example, an inlet face of the intake gas flow and an outlet face intended to open into the cylinder head of the engine. Preferably, the protection means are in the form of a channel, for example tubular, configured to receive at least a portion of the measuring sensor.

According to a first embodiment according to the present invention, the protection channel is formed in the upper wall of the collector housing. In other words, the protection channel is formed in the mass of the collector housing, which facilitates the realization (by limiting the manufacturing steps).

According to a second embodiment according to the present invention, the protection channel is attached (for example by welding) to the face, facing the mixing volume, of the upper wall of the collector housing.

Whatever the embodiment of the invention in question, the protection channel 20 preferably extends from the inlet face of the housing to the outlet face of the latter and opens into these two faces respectively. Thus, the protection channel directs and channels a portion of the unmixed intake gas with the flow of recirculated exhaust gas to the measuring sensor. Furthermore, the protection channel may be inclined with respect to a direction orthogonal to the inlet face of the housing.

In addition, the inner end of the measuring sensor is preferably arranged close to the outlet face of the housing to be flush with it. Thus, the positioning of the measuring sensor downstream of the collector housing (according to the flow direction of the gas mixture) does not prevent an injection of the recirculated exhaust gas upstream of the mixing volume (c that is, in a vicinity of the inlet face of the collector housing). In addition, the collector housing preferably comprises a through orifice, for example of cylindrical section, which opens into the protection channel and through which the measuring sensor is adapted to be introduced.

The through orifice may be inclined with respect to the protection channel, for example downstream towards the exit face of the collector housing, which limits the disturbances of the flow of intake gas flowing in the flow channel. protection caused by the inner end of the measuring sensor protruding. In addition, the through hole may comprise, at its outer end, an internal thread formed to cooperate with a complementary thread carried by the measuring sensor.

Preferably, the manifold comprises a tubular injection pipe of the recirculated exhaust gas stream into the mixing volume, which is formed in the upper wall of the collector housing.

In particular, the injection pipe may extend parallel to the inlet face of the casing, close to it, and comprise at least one injection orifice configured to feed the mixing volume with gas. Recirculated exhaust. Furthermore, the present invention also relates to a gas intake module for a vehicle engine cylinder head, said module comprising: a heat exchanger comprising a gas cooling heat exchange bundle; and a gas distribution manifold as specified above.

The figures of the appended drawing will make it clear how the invention can be realized. In these figures, identical references designate like elements.

Figure 1 is a perspective view of an embodiment of the gas intake module in an engine cylinder head according to the present invention. Figure 2 is a partial section of the intake module of Figure 1, along the line II-II.

Fig. 3 is a partial sectional view of the intake module of Fig. 1 along the line III-III (Fig. 2).

FIG. 4 is a perspective view of the outlet face of the manifold of the intake module of FIG.

FIG. 1 shows a gas intake module 1 in the cylinder head (not shown) of a motor vehicle engine which comprises a heat exchanger 2 comprising a heat exchange bundle 6 arranged for exchange heat with a first flow of gas (symbolized by the arrow G in dotted lines), here intake gases comprising air, flowing in the beam 6 of heat exchange. Subsequently, the "upstream" and "downstream" orientations are defined with respect to the flow direction of the intake gas flow G in the intake module 1, the intake gases G flowing from upstream to the downstream in module 1 according to the direction of flow of gases represented by the arrow X.

In addition, the "upper", "lower", "left" and "right" orientations are defined with respect to the orientation of the intake module 1 shown in perspective in FIG. 1 and in accordance with the orthonormal axes coordinate system ( X, Y, Z), the X axis being oriented from upstream to downstream, the Y axis being oriented from left to right and the Z axis being oriented from bottom to top, this is to say from the lower part of the intake module 1 towards its upper part.

The inlet gases G are introduced into the heat exchanger 2 via an inlet manifold 3, mounted upstream of the heat exchanger 2, and discharged through an outlet manifold 4, also called distribution manifold 4. mounted downstream of the heat exchanger 2 and intended to be connected to the cylinder head of the engine. The distribution manifold 4 allows a distributed admission into the cylinder head of the cooled gas flow G from the heat exchanger 2.

In order to understand the invention, each element of the particular example of intake module 1 according to the invention, illustrated by FIGS. 1 to 4, is described individually below. - Heat exchanger

As shown in FIGS. 1 to 4, the heat exchanger 2 comprises an exchanger casing 5 enveloping the cooling heat exchange bundle 6 comprising a plurality of stacked exchange elements 6A (FIG. 2). The spaces between the beam exchange elements form channels 6B for conducting the flow of gas to be cooled G, here the inlet gases. The beam exchange elements 6A 6 are hollow and conduct a heat transfer fluid for exchanging heat with the flow of gas to be cooled G flowing from upstream to downstream in the fluid conduit channels 6B (Figure 4).

The heat exchange bundle 6 is in the form of a parallelepiped extending along its length in the direction X of gas circulation and comprising an upstream inlet face through which the inlet gases to be cooled are introduced. G and a downstream outlet face through which are discharged the cooled inlet gas G.

- Input manifold

The inlet manifold 3 (Figure 1) is used to guide and distribute the flow of gas to be cooled G on the total surface of the input face of the beam 6 of heat exchange. For this purpose, the inlet manifold 3 is in the form of a substantially flared casing from upstream to downstream whose downstream end is connected to the upstream end of the exchanger casing 5. The collector 3 has an outlet face opening on the inlet face of the heat exchanger 2, and an inlet port 7, for example located laterally, that is to say, in a plane orthogonally located at its outlet face, through which the inlet gases to be cooled G are introduced into the inlet manifold 3.

Distribution manifold As shown in FIGS. 2 to 4, the distribution manifold 4, mounted downstream of the heat exchanger 2, comprises a gas intake inlet face 4A G into which the exit face opens. the heat exchange bundle 6 of the heat exchanger 2, and an outlet face 4B intended to be connected to the inlet face of the gases of the cylinder head (not shown).

The distribution manifold 4 comprises a manifold housing 8 guiding the gases introduced from the inlet face 4A to the cylinder head of the engine via the exit face 4B.

In addition, the distribution manifold 4 comprises an internal mixing volume V, delimited by the collector housing 8 and intended to receive the flow of intake gas G and a stream of recirculated exhaust gases from the engine (symbolized by the arrow H in dotted lines) and known to those skilled in the art under the abbreviation "EGR" (for "Exhaust Gas Recirculation").

As shown in Figures 3 and 4, the internal volume V is in a substantially flared form from upstream to downstream, the downstream end of said volume V communicating with corresponding intake ducts of the cylinder head.

As shown in FIG. 2, the distribution manifold 4 further comprises a pipe 9 for injecting the recirculated exhaust gas flow H. The pipe 9, of tubular shape, is formed in the upper wall 8S of the collector housing 8, the upstream side, and extends transversely to the X direction, from the left to the right throughout the length of the upper wall 8S.

The injection pipe 9 is arranged to introduce, inside the mixing volume V, a flow of recirculated exhaust gas H, so that it mixes with the flow of inlet gas H well upstream. of the breech.

As illustrated in FIG. 1, the collector housing 8 has a main body 8A for the circulation of the inlet gas flow G, and an extension body 8B comprising a base 10 for mounting a intake manifold 11 of the recirculated exhaust gas stream H in the injection pipe 9.

In addition, the distribution manifold 4 comprises an intake inlet of the recirculated exhaust gas stream H, in the form of an orifice (not shown) passing through the collector housing 8, for example in the direction X, of so as to allow the passage of the recirculated exhaust gas, the through orifice being formed in the base 10 of the extension body 8B.

The intake valve 11 comprises an intake valve (not shown) which is housed in the inlet of the distribution manifold 4 so as to allow, after opening, a passage of a portion of the flow of gas. recirculated exhaust H in the injection pipe 9 of the distribution manifold 4. For this purpose, the injection pipe 9 comprises at its left end an inlet orifice (not visible in FIG. 1) opening into the orifice of the extension body 8B.

As shown in Figure 2, the cross section (in the X direction) of the injection pipe 9 has a substantially trapezoidal shape.

In addition, the injection pipe is closed, at its left end, by a left wall and, at its right end, by a right wall, the left and right walls extending in a plane substantially perpendicular to the plane (X, Y).

In particular, the left wall is pierced by the inlet orifice for communicating the injection pipe 9 with the through orifice intended for the passage of recirculated exhaust gases H. As shown in FIGS. 2 to 4 , the injection pipe 9 is perforated by a plurality of injection ports 12, so as to inject the flow of recirculated exhaust gas H into the flow of cooled gas G. These orifices 12 are inclined upstream and down, in a plane (Z, X). In other words, the injection ports 12 are oriented countercurrently to the flow of the inlet gas G so as to form significant turbulence and promote the shearing of the cooled gas flow G by the flow of exhaust gas H.

Alternatively, instead of the plurality of injection ports 12, a longitudinal injection slot could be envisaged. Similarly, the orientation of the orifices and / or the slot could be different.

Moreover, as shown in the figures (and in particular in FIG. 2), the distribution manifold 4 of the invention comprises a removable measuring sensor 13 (here a temperature sensor, although it would be possible to envisage other sensor types, such as a pressure sensor). The sensor 13, of elongate shape, has at its upper end, a fixing sleeve 13A which is threaded on its outer part.

In order to mount the measuring sensor 13 on the collector housing 8, a through hole 14 is provided in the upper portion 8S of said housing 8, downstream thereof. The orifice 14, elongate and of circular cross-section, emerges, at its upper end, outside the collector housing 8. It further comprises, at this upper end, an internal thread 14A formed to cooperate, with adjustment with the external thread of the socket 13A.

In addition, the through-orifice 14 opens, through its lower end, into a channel 15 for protecting the measuring sensor 13 from the recirculated exhaust gas stream G. According to the embodiment of FIGS. FIGS. 1 to 4, the protection channel 15 is integrated in the mass of the collector housing 8. In particular, the channel 15, which has a circular cross section, is formed in the upper part 8S of said casing 8 and extends from the inlet face 4A to the outlet face 4B thereof, in which it opens respectively to its longitudinal ends 15A and 15B. In other words, in the example described, the protection channel 15 is open at its two upstream and downstream longitudinal ends 15A and 15B.

In an alternative embodiment of the invention (not shown), it is possible to report (for example by welding) the protective channel on the face, oriented towards the mixing volume V, of the upper wall 8S of the collector housing 8.

In the example described, as shown in FIG. 3, the protection channel 15 is inclined, in a plane (X, Y), with respect to a direction OO orthogonal to the input face 4A of the collector 4. In other words, , the channel 15 has an inclination with respect to the main direction of flow of the intake gas G. In addition, the protection channel 15 protrudes inside the internal volume of the mixture V.

Furthermore, as illustrated in FIG. 2, the through-orifice 14 is inclined relative to the protection channel 15 downstream in a plane (X, Z) and opens at its lower end into the latter . Thus, once the measuring sensor 13 is positioned in the through orifice 14 and fixed to the collector housing 8, the inner end 13I of the sensor 13 protrudes inside the protection channel 15 so as to be arranged close to the outlet face 4B of the collector 4 (and therefore downstream of the latter) flush with it.

Thanks to the invention, part of the intake gas G, coming from the heat exchanger 2, is separated from the rest of the incoming flow and is guided by the protection channel 15 towards the lower end 13I of the sensor 13 which Thus, the measurements made by the sensor 13 are not altered as the motor is used, since the motor is protected from the fouling resulting from the recirculated exhaust gases H.

Moreover, as shown in FIGS. 2 to 4, reinforcing struts 16 are provided between the lower and upper walls 8I and 8S of the collector housing 8. In particular, in the example described, the protection channel 15 passes through one of the reinforcement spacers 16.

It is obvious that the present invention is not limited to the shape of the protection channel previously described merely as an illustrative example. Indeed, the protection channel could just as well be curved, inclined in a plane (X, Z), or even have a cross section for example semi-circular.

Claims (15)

REVENDICATIONS1. Gas distribution manifold in the cylinder head of a vehicle engine 5, the manifold (4) comprising: - a collector housing (8) allowing the circulation of an intake gas flow (G); and an internal mixing volume (V) delimited by the collector housing (8) and intended to receive the intake gas flow (G) and a recirculated exhaust gas flow from the engine (H), characterized in that: - said collector housing (8) is configured to receive at least one measuring sensor (13), external to the collector (4), capable of measuring a parameter of the inlet gases (G); and the collector (4) has means (15) for protecting the measuring sensor (13) from the recirculated exhaust gas stream (H). 2. Collector according to the preceding claim, wherein the protection means (15) are in the form of a channel configured to receive at least a portion (13I) of the measuring sensor (13). 3. Collector according to the preceding claim, wherein the protective channel (15) is formed in the upper wall (8S) of the collector housing. 25 4. Collector according to claim 2, wherein the protective channel (15) is attached to the face, facing the mixing volume (V), the upper wall (8S) of the collector housing. 5. Collector according to one of claims 2 to 4, wherein the protection channel (15) extends from an inlet side of the inlet gas (4A) of the carter to an exit face (4B). ) of the latter and opens respectively into these two faces. 6. Collector according to the preceding claim, wherein the protection channel (15) is inclined relative to a direction (O-O) orthogonal to the inlet face (4A) of the housing. 7. Manifold according to one of the two preceding claims, wherein the inner end (13I) of the measuring sensor (13) is arranged close to the outlet face (4B) of the housing to flush it. 8. Collector according to one of claims 2 to 7, wherein the collector housing (8) has a through hole (14), preferably cylindrical, which opens into the protective channel (15) and by which the sensor of measurement (13) is intended to be introduced. 9. Collector according to the preceding claim, wherein the through hole (14) is inclined relative to the protective channel (15). 20 10. Collector according to one of the two preceding claims, wherein the through hole (14) has, at its outer end, an internal thread (14A) formed to cooperate with a complementary thread carried by the measuring sensor. 25 11. Collector according to one of claims 1 to 10, wherein the protective channel (15) is tubular. 12. Manifold according to one of the preceding claims, comprising a tubular pipe (9) for injecting the recirculated exhaust gas stream (H) into the mixing volume (V), said pipe being formed in the upper wall ( 8S) of the collector housing. 13. Manifold according to the preceding claim, wherein the injection pipe (9) extends parallel to an inlet side of the inlet gas (4A) of the housing, close to it. 14. Manifold according to the preceding claim, wherein the injection pipe (9) comprises at least one injection port (12) 10 configured to supply the mixture volume recirculated exhaust gas. 15. Gas intake module for vehicle engine cylinder head, said module (1) comprising: - a heat exchanger (2) having a gas cooling heat exchange beam (6); and a gas distribution manifold (4) as specified in one of claims 1 to 14.