MULTI-FUNCTIONAL MODULE FOR AN INTERNAL COMBUSTION ENGINE OF A MOTOR-VEHICLE

Description

Field of the invention

[0001] The present invention relates to a multi-functional module for an internal combustion engine of a motor-vehicle, incorporating a part of an exhaust gas recirculation system of the engine and a part of a cooling circuit of the engine, in particular said module comprising an EGR valve unit for regulating the recirculated exhaust gas flow and a heat exchanger for cooling the recirculated exhaust gases, by means of the engine coolant.

Prior art

[0002] Multi-functional modules of the type indicated above are yet known (see for example documents DE 10 2007 049 336 A1, EP 2 037 116 B1 , FR 2 875 540 A1 and EP 1 793 115 B1), wherein the multi-functional module comprises a central structural element, with a metal body having a face for attachment to an end face of the engine cylinder head. Such a body having an elongated shape according to a direction which is perpendicular to the longitudinal direction of the cylinder head in the mounted condition of said module on the engine.

[0003] A conduit for circulation of the exhaust gases and a conduit for circulation of the engine coolant are formed within said metal body of the central structural element. Such conduits extend starting form an inlet opening of the exhaust gases and an inlet opening of the coolant, said inlet openings are positioned on said attachment face and are intended to communicate respectively with the engine exhaust manifold and with a coolant jacket of the cylinder head.

[0004] The exhaust gases conduit ends into an exhaust gases outlet opening intended to communicate with the engine intake manifold, whereas said coolant conduit flows into at least one coolant outlet opening to which a thermostatic valve is associated for controlling a connection with a radiator of the engine cooling system.

[0005] In such multi-functional modules, said EGR valve unit for regulating the recirculated exhaust gas flow is mounted on a first end face of said central structural element elongated body, and is operatively interposed along said exhaust gases conduit. Furthermore, said heat exchanger for cooling exhaust gases with the coolant is mounted on a second end face of said elongated body of the central structural element, which is opposite to said first end face on which said EGR valve unit is mounted. The heat exchanger has internal conduits in heat exchange relationship to each other, which are respectively operatively interposed along said exhaust gases conduit and said coolant conduit. A by-pass conduit for exhaust gas is formed within said elongated body of the central structural element, through which exhaust gases can flow towards said exhaust gases outlet opening without passing through said heat exchanger, in said by-pass conduit being interposed a by-pass valve operated by means of a vacuum actuator carried by said multi-functional module.

[0006] Multi-functional modules of the type indicated above which has been produced since now have several drawbacks. Firstly, the EGR valve unit is subjected to carbon deposits (so called "EGR soot") due to the exhaust gas flow which passes through thereof, with consequent efficiency reduction of such component with the passing of time. Furthermore, all the aforementioned known solutions provide a vacuum tank integrated to the central structural element of the module, such a vacuum tank results necessary for controlling the vacuum actuator which controls the aforementioned by-pass valve. Such a vacuum tank is mounted at a module end, adjacent to the heat exchanger, causing a reduction of the available space of the heat exchanger. Therefore it is mandatory to use a relatively small heat exchanger, with consequent less efficiency of the exhaust gases cooling. Another drawback that occurs in the known solutions consists in slowing down the exhaust gas flow that passes through the heat exchanger, due to gas density reduction that is determined while gas are cooled in the heat exchanger.

Object of the invention

[0007] The object that is on the basis of the present invention is to overcome above mentioned drawbacks which occur in the known solutions.

[0008] A further object of the invention is to provide a multi-functional module with limited dimensions, reduced weight, inexpensive to be manufactured.

[0009] Again a further object of the present invention is to provide a multi-functional module which remains efficient in all its functions during the entire life of the engine to which the module is associated.

Summary of the invention

[0010] In view of achieving the above objects, the invention relates to a multi-functional module for an internal combustion engine having all the features that have been indicated above and characterized in that said EGR valve unit is operatively positioned along the exhaust gases conduit upstream of said heat exchanger, in such a way that when said EGR valve unit is in an opened condition, the exhaust gases pass through said EGR valve unit, before being cooled in the heat exchanger.

[0011] Thanks to this feature, the exhaust gases pass through the EGR valve at a temperature which is considerably higher than what occurs in the known solutions, so causing reduction or entire cancellation of risk of carbon deposits within the EGR valve and ensuring that such valve maintains constant efficiency for the entire operative life of the engine.

[0012] The module according to the invention is also characterized in that said vacuum actuator which controls the by-pass valve is arranged for being operated by a vacuum source external to the module, whereby said module is without of any vacuum source or tank.

[0013] Thanks to this feature, the weight and the overall dimensions of the module are considerably reduced. In particular, compared to the known solutions in which next to the heat exchanger is provided said vacuum tank, the multifunctional module according to the invention has the advantage that the entire second end face of the body of the central structural element can be entirely occupied by the heat exchanger. This allows to obtain a more efficient cooling of the exhaust gases, using a larger heat exchanger without increasing the overall size of the module. Or it is thus possible to use a heat exchanger with similar dimensions to the known solutions, but considerably decreasing the overall size of the module.

[0014] According to a further preferred feature, said heat exchanger is configured in such a way as the exhaust gases which pass through thereof follow a U-shaped path.

[0015] Thanks to this feature, considering an equal cooling efficiency of the exhaust gases, the overall dimensions of the heat exchanger in the longitudinal direction of the module can be considerably reduced.

[0016] According to a further preferred feature, the U-shaped passage for the exhaust gases through the heat exchanger is defined by a first row of tubes or flat channels for the exhaust gas flow in a first direction, by a second row of tubes or flat channels for the exhaust gas flow in a second direction opposite to the first direction, and by an intermediate chamber which connects the tubes or flat channels of the first row to the tubes or flat channels of the second row.

[0017] Thanks to this feature, it is possible to provide, with a simple and low cost structure, a variation of the overall section for the passage of the exhaust gases while they proceed to the heat exchanger. In particular it is possible to provide that tubes or flat channels of said second row define an overall passage section lower than the overall passage section defined by tubes or flat channels of the first row, so as to counteract a reduction of the exhaust gases speed resulting from the reduction of density due to the cooling.

Detailed description of the preferred embodiment

[0018] Further features and advantages of the invention will become apparent from the following description with reference to the annexed figures, given purely by way of non limiting example, in which:

• figure 1 is a diagram of a preferred embodiment of the multi-functional module according to the present invention, where has been shown only the exhaust gas circuit,
• figure 2 is a diagram similar to figure 1, wherein has been shown only the engine coolant circuit,
• figure 3 shows a perspective view of the aforesaid preferred embodiment of the multi-functional module according to the present invention,
• figures 4 and 5 show two exploded views of the module illustrated in figure 3, where have been shown respectively the exhaust gases circuit and the engine coolant circuit,
• figures 6, 7 are two further perspective views in enlarged scale, where some internal conduits of the module according to the invention have been illustrated as solid parts, for major clarity, and
• figure 8 shows a diagrammatic sectional view of the heat exchanger forming part of the multi-functional module according to the invention.

[0019] With reference to the annexed drawings, the reference number 1 indicates a preferred embodiment of the multi-functional module for an internal combustion engine of a motor-vehicle according to the present invention.

[0020] Figures 1, 2 diagrammatically shown the cylinder head T of a multicylinder engine E, having an intake manifold CA for the air supply, coming from a suction duct 5 to the engine cylinders, and an exhaust manifold CS for discharging in an exhaust conduit 17 the outgoing gas from the engine cylinders. Figure 2 also diagrammatically illustrates the cooling jacket J of the cylinders head T.

[0021] The module 1 incorporates a part of the exhaust gas recirculation system of the engine and a part of the cooling circuit of the engine. In particular said module comprises an EGR valve unit 3 for regulating the recirculated exhaust gas flow and a heat exchanger 4 for cooling the recirculated exhaust gases by means of the engine coolant.

[0022] The EGR valve unit 3 and the heat exchanger 4 are mounted at two opposite ends of a central structural element 2. In particular with reference to figures 1-5, the central structural element 2 comprises a metal body (such as aluminium) having a face (indicated with P6 in figures 3-5) for attachment to an end face of the cylinder head T of the engine E (see figures 1, 2). Such a connection can be realized for example by means of screws, providing also a seal between faces in contact of the structural element body 2 and of the cylinder head T. Such constructive details have not been illustrated so getting more simple the drawings.

[0023] As shown in figures 1, 2, the body of the structural element 2 has an elongated shape according to a direction which is perpendicular to the longitudinal direction of the cylinder head. A conduit 6 for circulation of the exhaust gases (in particular see figures 1, 4, 7) and a conduit 7 for circulation of the engine coolant (in particular see figures 2, 5, 6) are formed within said central structural element metal body 2.

[0024] The exhaust gases conduit 6 extends starting from an inlet opening 9 of the exhaust gas positioned on said face P6 of the body 2 provided for attachment with the cylinder head (see figures 4 and 6, 7). The coolant conduit 7 extends starting from an inlet opening 8 positioned also in this case on said attachment face P6.

[0025] As seen in figure 1, the opening 9 for inlet in the module 1 of the exhaust gases communicates with the intake manifold CS by means of a conduit 24 formed in the cylinder head T. Otherwise as seen in figure 2, the opening 8 for inlet of the coolant in the module 1 communicates with the coolant jacket J of the cylinder head T.

[0026] Again with reference to figure 1, the exhaust gases conduit 6 follows a path, which will be described in detail below, through the body 2, up to ends into an outlet opening 10 connected to the suction duct 5, so as to enable recirculation of exhaust gases in the engine intake manifold.

[0027] With reference to figure 2, the coolant conduit 7 communicates with an outlet opening 11 to which a thermostatic valve 19 is associated for controlling a connection with the radiator of the engine cooling system.

[0028] The EGR valve unit 3 and the heat exchanger 2 are mounted at opposite ends of the central structural element 2.

[0029] As will be better illustrated in the following, the EGR valve unit 3 is operatively interposed in the exhaust gases conduit 6, for regulating the recirculated exhaust gas flow . The heat exchanger 4 has internal conduits, which also will be better illustrated in the following, which are in heat exchange relationship to each other, and which are respectively operatively interposed along said exhaust gases conduit 6 and said coolant conduit 7.

[0030] A by-pass conduit 65 for exhaust gases is formed within said elongated body of the central structural element 2 (see figure 1), through which exhaust gases can flow towards said exhaust gases outlet opening 10 without passing through said heat exchanger 4. A by-pass valve 13 (only diagrammatically shown in figure 1) is interposed inside said by-pass conduit 65 which is operated by means of a vacuum actuator 14 carried by said multi-functional module 1. The actuator 14 is shown in figures 3-5 and only in a diagrammatic way in figure 1. Using a vacuum actuator is necessary in order to efficiently develop the force that must be applied to the movable member of the by-pass valve. In the illustrated example in figures 4,5, the actuator body is rigidly fixed on the upper face P4 (with reference to drawings) of the body 2 and controls a stem which controls the movable member of the by-pass valve by means of a lever.

[0031] A first important feature of the present invention is that the EGR valve unit 3 is operatively positioned along the exhaust gases conduit 6 upstream the heat exchanger 4, in such a way that when said EGR valve unit is in an opened condition, the exhaust gases pass through said EGR valve unit 3, before being cooled in the heat exchanger 4.

[0032] Thanks to this feature, the exhaust gases pass through the EGR valve with a temperature which is considerably higher than what occurs in the known solution, so decreasing or entirely cancelling the risk of carbon deposits within the EGR valve 3 and ensuring that this valve maintains a constant efficiency for the entire life of the engine.

[0033] A further feature of the module according to the invention is that the vacuum actuator 14 which controls the by pass valve 13 is arranged for being operative by a vacuum pump 15 (figure 1) external to the module. The communication of the actuator 14 with the vacuum pump 15 is controlled by an electrovalve 16 of the type on-off. The electrovalve 16 is illustrated in figures 3-5 and only diagrammatically in figure 1. The actuator 14 is controlled by the vacuum pump 15 in order to open the by-pass conduit 65 during a warm-up phase of the engine, so when cooling of the exhaust gases is not required. In the module according to the invention, otherwise of the known solutions, it is not provided any vacuum tank in order to operate the actuator 14. Thanks to this feature, weight and overall size of the module are considerably reduced. In particular, compared to the known solutions in which next to the heat exchanger is provided said vacuum tank, the multifunctional module according to the invention has the advantage that the end face of the body 2 in which is mounted the heat exchanger can be entirely occupied by the heat exchanger. This fact permits to obtain a more efficient cooling of the exhaust gases, using a heat exchanger bigger, but without increasing the overall size of the module. Or it is also possible to use a heat exchanger with overall size similar to what is provided in the known solutions, so considerably decreasing the overall size of the module.

[0034] In the following, it will be described in detail the path of the exhaust gas in the preferred embodiment of the module according to the invention.

[0035] In particular with reference to figures 4 and 7, the exhaust gases conduit 6 comprises a blind conduit portion 60 which extends through the central structural element body 2 from said inlet opening 9 positioned on the attachment face of the central structural element 2. From the conduit portion 60 branches a further conduit portion 61 which extends in a parallel direction to the longitudinal direction of the body 2, up to ends into an opening 23 on the end face P3 on which is mounted the EGR valve unit 3. Adjacent to the opening 23 is provided a conduit portion 62 in which the conduit portion 61 communicates with a further conduit portion 63 which runs in parallel to the conduit portion 61 and extends from the end face P3 of the body 2 up to the opposite end face P2 on which is mounted the heat exchanger 4, which flows into an opening 12 which communicates with an exhaust gases inlet in the heat exchanger 4.

[0036] The communication of the conduit portion 61 with the conduit portion 62 (figure 4) is controlled by the EGR valve unit which comprises a body which is rigidly connected by screws (not shown) to the body of the element 2 and including an electric actuator for the position control of a shutter O which cooperates with a valve seat (not shown in the drawings) formed on the wall of the conduit portion 61. The shutter O is axially movable between a rest position on the valve seat, in which the communication between the conduit portions 61, 62 is interrupted, and a position which is spaced from the valve seat, in which the aforesaid communication is open.

[0037] Again with reference to figures 4 and 8, the end face of the central structural element body 2 is entirely occupied by the heat exchanger 4. Such heat exchanger 4 is configured in such a way as the exhaust gas which pass through thereof follow a U-shaped path. Thanks to this feature, with equal efficiency of exhaust gas cooling, the overall size of the heat exchanger in the longitudinal direction of the module can be considerably reduced.

[0038] The U-shaped path for the exhaust gases through the heat exchanger 4 is defined by a first row of tubes 41 (in the case illustrated in the drawings) or alternatively by flat channels, for exhaust gas flow in a first direction, by a second row of tubes 41 or alternatively by flat channels for the exhaust gas flow in a second direction which is opposite to the first direction, and by an intermediate chamber 44 which connects the tubes or the flat channels of the first row to the tubes or the plates channel of the second row.

[0039] In the preferred embodiment of the heat exchanger 4 which is here illustrated, the tubes or flat channels of the second row (positioned downstream of the first row) define a total section of passage smaller than the total section of passage defined by the tubes or flat channels of the first row in such a way as counteracting a reduction of exhaust gases speed caused by the reduction of density due to the cooling. In the illustrated example that is obtained providing tubes 41 all of the same section, but providing a number of tubes of the upstream first row bigger than the number of tubes of the downstream second row.

[0040] The tubes 41 of the heat exchanger are all surrounded by a chamber 43 filled of the coolant.

[0041] The exhaust gases which leave the heat exchanger, enter again in the body of the element 2 merging in the by-pass conduit 65 (figures 1 and 7) and in the outlet opening 10 connected to the suction duct 5, which flows on the upper face P4 of the metal body of the element 2. A fitting element for the connection of a pipe 21 is mounted at the outlet opening 10, in which said pipe 21 let flows the recirculated exhaust gas in the suction duct 5.

[0042] In the following, it will be described more in detail the path of the coolant in the preferred embodiment of the module according to the invention.

[0043] With reference to figures 2, 5 and 6, the coolant conduit 7 comprises a conduit portion 71 which extends through the body of the central structural element 2 from said inlet opening 8 positioned on said attachment face P6 up to the opposite face P1 of the central structural element 2, wherein said conduit portion 71 ends into an outlet opening 11. A fitting element 18 is mounted at the opening 11 and said fitting element 18 incorporates the thermostatic valve 19 diagrammatically shown in figure 2 (not illustrated in figure 5), which controls the feeding of the coolant to the radiator of the cooling system.

[0044] A further conduit portion 72 branches from the conduit portion 71 in direction of the end face P3 of the central structural element 2 to which the EGR valve unit 3 is associated and which flows in a chamber 73 which is adjacent to said end face P3, for the cooling of the EGR valve unit 3. A further conduit portion 74 extends longitudinally along said central structural element 2 starting from a chamber 73 up to an inlet 22 of the coolant in the heat exchanger 4. Through the inlet 22, the coolant enters in the chamber 43 (figure 8) of the heat exchanger 4, where cools the exhaust gases which circulate in the tubes 41. The coolant leaves the heat exchanger through an outlet fitting 42 (figure 6), connected with the cooler of the engine oil, which is part of the engine cooling system. From the conduit portion 74 (figure 5) branches a further conduit (not illustrated) which ends in the face P1 of the body 2, where is fixed a fitting element 22 connected with the cabin heater of the motor-vehicle.

[0045] In the following it will be described the operation of the module 1 according to the present invention.

[0046] In figures of the annexed drawings, arrows F1 and F2 indicates respectively the exhaust gas flow and the coolant flow.

[0047] During the operation of the engine E, a part of the exhaust gas flow is recirculated to the engine intake by means of the module 1. In particular, a part of the exhaust gas flow passes through the intake manifold in the conduit 24 (figure 1) of the cylinders head T in order to enter in the inlet opening 9 in the module 1. If the EGR valve is opened, the exhaust gases entered in the opening 9 flow through the successive conduit portion 60-63 (figures 4 and 6) up to enter in the inlet of the heat exchanger 4. Subsequently, the gas flow in a direction and than in the opposite direction through the two rows of tubes (or flat channels) 41 of the heat exchanger 4 up to flow out from the module 1 through the opening 10 and so flow into the suction duct 5 (figure 1).

[0048] The electric actuator of the EGR valve unit 3 controls the stem O for regulating the recirculated exhaust gas flow. The actuator of the EGR valve is controlled by the engine control unit, on the basis of one or more engine operation parameters, according to a known technique.

[0049] Because the exhaust gas flow through the stem seat O of the EGR valve before being cooled in the heat exchanger 4 (there is only a reduced cooling caused by the coolant in the chamber 73) the gas are still relatively hot at the stem O, so consequently the risk of carbon deposit is reduced or completely eliminated, which could prejudice the efficiency of the EGR valve in the time.

[0050] During the warm-up phase of the engine, when the cooling of the exhaust gases in the exchanger 4 is not required, the actuator 14 controls the opening of the by-pass valve 13, so that the gases flow out from the module 1 without passing through the heat exchanger 4. The actuator 14 becomes operative by means of the opening of the electrovalve 16 and activating the vacuum pump 15 (which is not part of the module 1, being integrated in the engine E). Therefore, a like prior art, the module 1 doesn't include a vacuum tank for supplying the actuator 14, with consequent possibility of adopt a heat exchanger bigger and more efficient, which occupies the entire end face P2 of the metal body 2, without increasing the overall size of the module 1. The configuration with U-shape of the path of the exhaust gases in the heat exchanger 4 enables a reduction of the dimensions of the heat exchanger 4 in the longitudinal direction of the body 2. The predisposition of the two different rows of tubes 41 or flat channels communicating with an intermediate chamber 44 enables also to provide an overall passage section for the exhaust gases which is reduced along the path of the exhaust gases, so as to counteract the reduction of speed due to the reduction of density caused by the cooling.

[0051] With reference to figures 1 and 5, 6, the coolant coming from the cooling jacket J of the cylinders head flows into the inlet opening 8 of the module 1. Part of the flow pass through the conduit portion 71 and cause out the module 1 through the fitting element 18 when the thermostatic valve 19 (figure 1) is open, so as to flow towards the radiator of the motor-vehicle. Part of the flow of the coolant subsequently flows through the conduit portion 71, 72, the chamber 73 (which cools the EGR valve) and a conduit portion 74 up to flows in to the chamber 43 of the heat exchanger, where the exhaust gas are cooled. The coolant leaving the heat exchanger 44 goes out from the module 1 through the fitting element 42 (figure 6) from which it has been directed to the cooler of the engine oil of the motor-vehicle cooling system. Part of the coolant goes out instead from the module 1 through the fitting element 22, from which it is directed to the cabin heater.

[0052] As result evident from the above description, the multi-functional module according to the invention combines a simple configuration and economical process for manufacturing with limited overall size features, low weight and constant efficiency in the time.

[0053] Naturally, while the principle of the invention remains the same, the details of construction and the embodiments may widely wary with respect to what has been described and illustrated purely by way of example, without departing from the scope of the present invention as in the appended claims.

Claims

1. Multi-functional module (1) for an internal combustion engine (E) of a motor-vehicle, incorporating a part of an exhaust gas recirculation system of the engine and a part of a cooling circuit of the engine, said module comprising an EGR valve unit (3) for regulating the recirculated exhaust gas flow and a heat exchanger (4) for cooling the recirculated exhaust gases, by means of the engine coolant, further wherein:

- said multi-functional module comprises a central structural element (2), with a metal body having a face (P6) for attachment to an end face of the cylinder head (T) of the engine (E), such a body having an elongated shape according to a direction which is perpendicular to the longitudinal direction of the cylinder head, in the mounted condition of said module on the engine,

- a conduit (6) for circulation of the exhaust gases and a conduit (7) for circulation of the engine coolant are formed within said metal body of the central structural element (2), said conduits (6, 7) extending starting from an inlet opening (9) of the exhaust gases and an inlet opening (8) of the coolant, said inlet openings (8,9) being positioned on said attachment face (P6) and being respectively for communication with the engine exhaust manifold and with a coolant jacket of the cylinder head,

- said exhaust gas conduit (6) ends into an exhaust gas outlet opening (10) intended to communicate with the engine intake manifold, whereas said coolant conduit (7) ends into at least one coolant outlet opening (11) to which is associatable a thermostatic valve (19) for controlling a connection to the radiator of the engine cooling system,

- said EGR valve unit (3) for regulating the recirculated exhaust gas flow is mounted on a first end face (P3) of said elongated body of the central structural element (2), and is operatively interposed along said exhaust gas conduit (6),

- said heat exchanger (4) for cooling the exhaust gases by the coolant is mounted on a second end face (P2) of said elongated body of the central structural element (2), which is opposite to said first end face (P3) on which said EGR valve unit is mounted (3), said heat exchanger (4) having internal conduits (41, 43) in heat exchange relationship to each other, which are respectively operatively interposed along said exhaust gas conduit (6) and said coolant conduit (7),

- a by-pass conduit (65) for the exhaust gases is formed within said elongated body of central structural element (2), through which the exhaust gases can flow towards said exhaust gas outlet opening (10) without passing through said heat exchanger (4),

- a by-pass valve (13) is interposed inside said by-pass conduit (65) which is operated by means of a vacuum actuator (14) carried by said multi-functional module (1),

- said multi-functional module (1) being characterized in that said EGR valve unit (3) is operatively positioned along the exhaust gas conduit (6) upstream of said heat exchanger (4), in such a way that when said EGR valve unit (3) is in an opened condition, the exhaust gases pass through said EGR valve unit (3), before being cooled in the heat exchanger (4), and

- in that said vacuum actuator (14) which controls the by-pass valve (13) is arranged for being operated by a vacuum source external to the module (1), whereby said module is deprived of any vacuum source or tank.

2. Multi-functional module (1) according to claim 1, characterized in that said second end face (P2) of the body of the central structural element (2) is entirely occupied by said heat exchanger (4).

3. Multi-functional module (1) according to claim 1, characterized in that said heat exchanger is configured in such a way that the exhaust gases which pass through the heat exchanger follow a U-shaped path.

4. Multi-functional module (1) according to claim 3, characterized in that the U-shaped path for the exhaust gases trough the heat exchanger (4) is defined by a first row of tubes or flat channels (41) for the flow of the exhaust gases in a first direction, by a second row of tubes or flat channels (41) for the flow of the exhaust gases in a second direction opposite to the first direction and by an intermediate chamber (44) which connects the tubes or flat channels of the first row to the tubes or flat channels of the second row.

5. Multi-functional module (1) according to claim 4, characterized in that the tubes or flat channels (41) of said second row define an overall passage cross-sectional area smaller than the overall passage cross-sectional area defined by the tubes or flat channels (41) of the first row, in such a way as to counteract a reduction of the speed of the exhaust gases caused by the reduction of density due to cooling.

6. Multi-functional module (1) according to claim 1, characterized in that said cooling conduit (7) comprises:

- a first conduit portion (71) which extends through the central structural element body (2) from said inlet opening (8) positioned at said attachment face (P6) up to an opposite face (P1) of the central structural element (2), where said outlet opening (11) is located, to which the thermostatic valve (19) is associated;

- a second conduit portion (71) which branches from the first conduit portion (71) in direction of said first end face (P3) of the central structural element (2) to which the EGR valve unit (3) is associated and which terminates in a chamber (73) adjacent to said first end face (P3) of the central structural element (2) for cooling the EGR valve unit (3), and

- a third conduit portion (74) which extends longitudinally along said central structural element (2) starting from said chamber (73) up to an inlet (22) of the coolant in the heat exchanger (4),

- said heat exchanger (4) having an outlet (42) for the coolant intended to be connected with an external element of the engine cooling circuit, such as a cooler for the engine oil.

7. Multi-functional module according to claim 1, characterized in that said exhaust gas conduit (6) comprises:

- a conduit portion (60, 61) for the exhaust gases, operatively positioned upstream of the EGR valve unit (3) and which is extended through the body of the central structural element (2) from said inlet opening (9) for the exhaust gases positioned on said attachment face (P6) of the central structural element (2) up to said first end face (P3) of the central structural element (2),

- a conduit portion (62, 63) for the exhaust gases which is operatively positioned downstream the EGR valve unit (3), and which is extended through the body of the central structural element (2) up to said second end face (P2) of the central structural element (2) where it merges into an inlet for the exhaust gases in the heat exchanger (4), the communication between said upstream portion and said downstream portion of the exhaust gas conduit (6) being controlled by said EGR valve unit (3),

- a terminal conduit portion for the exhaust gases formed in said body of the central structural element (2), which connects an outlet of the exhaust gases from the heat exchanger (4) with said outlet opening (10) of the exhaust gases of the multi-functional module (1),

- said by-pass conduit (65) being defined by a conduit formed in the body of the central structural element (2) which directly connects said conduit portion (62, 63) for the exhaust gases downstream of the EGR valve unit (3) with said terminal conduit portion for the exhaust gases.

8. Multi-functional module (1) according to claim 7, characterized in that said conduit portion (60, 61) for the exhaust gases which is operatively positioned upstream of the EGR valve unit (3) ends into an opening (23) on said first end face (P3) of the body of the central structural element (2) and in that said EGR valve unit (3) comprises a valve shutter (8) which is provided movable within said opening (23) of said first end face (P3) and which cooperates with a valve seat formed within said central structural element for controlling the communication between the upstream and downstream portions of the conduit (6) for the exhaust gases.

Ansprüche

1. Multifunktionsmodul (1) für einen Verbrennungsmotor (E) eines Motorfahrzeugs mit einem Teil eines Abgasrezirkulationssystems des Motors und einem Teil eines Kühlkreises des Motors, wobei das Modul eine EGR-Ventileinheit (3) zum Regeln des rezirkulierten Abgasstroms und einen Wärmetauscher (4) zum Kühlen der rezirkulierten Abgase mittels eines Motorkühlmittels aufweist, wobei ferner:

- das Multifunktionsmodul ein zentrales strukturelles Element (2) aufweist mit einem Metallkörper mit einer Fläche (P6) zur Befestigung an einer Stirnfläche des Zylinderkopfs (T) des Motors (E), wobei ein derartiger Körper eine längliche Form entsprechend einer Richtung aufweist, die senkrecht zu der Längsrichtung des Zylinderkopfs ist, wenn das Modul an dem Motor montiert ist,

- eine Leitung (6) zur Zirkulation der Abgase und eine Leitung (7) zur Zirkulation des Motorkühlmittels in dem Metallkörper des zentralen strukturellen Elements (2) ausgebildet sind, wobei die Leitungen (6, 7) sich ausgehend von einer Einlassöffnung (9) für die Abgase und einer Einlassöffnung (8) für das Kühlmittel aus erstrecken, wobei die Einlassöffnungen (8, 9) in der Befestigungsfläche (P6) angeordnet sind und entsprechend mit einem Motorabgasverteiler und mit einem Kühlmantel des Zylinderkopfs in Verbindung stehen,

- die Abgasleitung (6) in eine Abgasauslassöffnung (10) mündet, die dafür vorgesehen ist, mit dem Motoreinlassverteiler in Verbindung zu stehen, während die Kühlmittelleitung (7) in mindestens eine Kühlmittelauslassöffnung (11) mündet, die mit einem Thermostatventil (19) zur Steuerung einer Verbindung zu dem Kühler des Motorkühlsystems verbindbar ist,

- die EGR-Ventileinheit (3) zum Regeln des rezirkulierten Abgasstroms an einer ersten Stirnfläche (P3) des länglichen Körpers des zentralen strukturellen Elements (2) montiert und funktionsmäßig im Zwischenbereich entlang der Abgasleitung (6) angeordnet ist,

- der Wärmetauscher (4) zum Kühlen der Abgase durch das Kühlmittel an einer zweiten Stirnfläche (P2) des länglichen Körpers des zentralen strukturellen Elements (2) montiert ist, die gegenüberliegend zu der ersten Stirnfläche (P3) liegt, an der die EGR-Ventileinheit (3) montiert ist, wobei der Wärmetauscher (4) interne Leitungen (41, 43), die entsprechend zum Wärmetauschen zueinander angeordnet sind, aufweist, die entsprechend funktionsmäßig im Zwischenbereich entlang der Abgasleitung (6) und der Kühlmittelleitung (7) angeordnet sind,

- eine Umgehungsleitung (65) für die Abgase in dem länglichen Körper des zentralen strukturellen Elements (2) ausgebildet ist, durch welche die Abgase zu der Abgasauslassöffnung (10) strömen, ohne den Wärmetauscher (4) zu durchlaufen,

- ein Umgehungsventil (13) in der Umgehungsleitung (65) angeordnet ist, das mittels eines Vakuum-Aktuators (14) betrieben wird, der von dem Multifunktionsmodul (1) getragen wird,

- das Multifunktionsmodul (1) dadurch gekennzeichnet ist, dass die EGR-Ventileinheit (3) funktionsmäßig entlang der Abgasleitung (6) stromaufwärts von dem Wärmetauscher (4) so angeordnet ist, dass, wenn die EGR-Ventileinheit (3) in der offenen Stellung ist, die Abgase durch die EGR-Ventileinheit (3) strömen, bevor sie in dem Wärmetauscher (4) gekühlt werden, und

- dass der Vakuum-Aktuator (14), der das Umgehungsventil (13) steuert, ausgebildet ist, mittels einer Vakuumquelle, die außerhalb des Moduls (1) liegt, betrieben zu werden, wodurch das Modul ohne Vakuumquelle oder Vakuumbehälter ist.

2. Multifunktionsmodul (1) nach Anspruch 1, dadurch gekennzeichnet, dass die zweite Stirnfläche (P2) des Körpers des zentralen strukturellen Elements (2) vollständig von dem Wärmetauscher (4) eingenommen ist.

3. Multifunktionsmodul (1) nach Anspruch 1, dadurch gekennzeichnet, dass der Wärmetauscher so ausgebildet ist, dass die Abgase, die den Wärmetauscher durchlaufen, einen U-förmigen Weg nehmen.

4. Multifunktionsmodul (1) nach Anspruch 3, dadurch gekennzeichnet, dass der U-förmige Weg für die Abgase durch den Wärmetauscher (4) durch eine erste Reihe aus Rohren oder flachen Kanälen (41) für das Strömen der Abgase in einer ersten Richtung, durch eine zweite Reihe aus Rohren oder flachen Kanälen (41) für das Strömen der Abgase in einer zweiten Richtung entgegengesetzt zu der ersten Richtung und durch eine Zwischenkammer (44) gebildet ist, die die Rohre oder die flachen Kanäle der ersten Reihe mit den Rohren oder flachen Kanälen der zweiten Reihe verbindet.

5. Multifunktionsmodul (1) nach Anspruch 4, dadurch gekennzeichnet, dass die Rohre oder die flachen Kanäle (41) der zweiten Reihe eine Gesamtdurchgangsquerschnittsfläche bilden, die kleiner ist als die Gesamtdurchgangsquerschnittsfläche, die durch die Rohre oder flachen Kanäle (41) der ersten Reihe gebildet ist, derart, dass einer Verringerung der Geschwindigkeit der Abgase, die durch eine Reduzierung der Dichte aufgrund der Abkühlung hervorgerufen wird, entgegengewirkt wird.

6. Multifunktionsmodul (1) nach Anspruch 1, dadurch gekennzeichnet, dass die Kühlleitung (7) aufweist:

- einen ersten Leitungsbereich (71), der sich durch den Körper des zentralen strukturellen Elements (2) von der Einlassöffnung (8), die an der Befestigungsfläche (P6) angeordnet ist, zu einer gegenüberliegenden Fläche (P1) des zentralen strukturellen Elements (2) erstreckt, an der die Ausgangsöffnung (11) angeordnet ist, mit der das Thermostatventil (19) verbunden ist;

- einen zweiten Leitungsbereich (71), der von dem ersten Leitungsbereich (71) in Richtung zu der ersten Stirnfläche (P3) des zentralen strukturellen Elements (2) abzweigt, mit der die EGR-Einheit (3) verbunden ist und die in einer Kammer (73) mündet, die benachbart zu der ersten Stirnfläche (P3) des zentralen strukturellen Elements (2) zur Kühlung der EGR-Ventileinheit (3) angeordnet ist, und

- einen dritten Leitungsbereich (74), der sich in Längsrichtung entlang des zentralen strukturellen Elements (2) ausgehend von der Kammer (73) bis zu einem Einlass (22) des Kühlmittels in den Wärmetauscher (4) erstreckt,

- wobei der Wärmetauscher (4) einen Auslass (42) für das Kühlmittel aufweist, der mit einem externen Element des Motorkühlkreises, etwa einem Kühler für das Motoröl, zu verbinden ist.

7. Multifunktionsmodul (1) nach Anspruch 1, dadurch gekennzeichnet, dass die Abgasleitung (6) aufweist:

- einen Leitungsbereich (60, 61) für die Abgase, der funktionsmäßig stromaufwärts von der EGR-Ventileinheit (3) angeordnet ist und der sich durch den Körper des zentralen strukturellen Elements (2) von der Einlassöffnung (9) für die Abgase, die an der Befestigungsfläche (P6) des zentralen strukturellen Elements (2) angeordnet ist, bis zu der ersten Stirnfläche (P3) des zentralen strukturellen Elements (2) erstreckt,

- einen Leitungsbereich (62, 63) für die Abgase, der funktionsmäßig stromabwärts von der EGR-Ventileinheit (3) angeordnet ist und der sich durch den Körper des zentralen strukturellen Elements (2) bis zu der zweiten Stirnfläche (P2) des zentralen strukturellen Elements (2) erstreckt, wo sie in einen Einlass für die Abgase in dem Wärmetauscher (4) mündet, wobei die Verbindung zwischen dem stromaufwärtsseitigen Bereich und dem stromabwärtsseitigen Bereich der Abgasleitung (6) von der EGR-Ventileinheit (3) gesteuert ist,

- einen Anschlussleitungsbereich für die Abgase, der in dem Körper des zentralen strukturellen Elements (2) ausgebildet ist und der einen Auslass der Abgase aus dem Wärmetauscher (4) mit der Auslassöffnung (10) der Abgase des Multifunktionsmoduls (1) verbindet,

- wobei die Umgehungsleitung (65) durch eine Leitung gebildet ist, die in dem Körper des zentralen strukturellen Elements (2) ausgebildet ist, die den Leitungsbereich (62, 63) für die Abgase stromabwärts von der EGR-Ventileinheit (3) direkt mit dem Anschlussleitungsbereich für die Abgase verbindet.

8. Multifunktionsmodul (1) nach Anspruch 7, dadurch gekennzeichnet, dass der Leitungsbereich (60, 61) für die Abgase, der funktionsmäßig stromaufwärts von der EGR-Ventileinheit (3) angeordnet ist, in eine Öffnung (23) auf der ersten Stirnfläche (P3) des Körpers des zentralen strukturellen Elements (2) mündet, und dass die EGR-Ventileinheit (3) einen Ventilverschluss (8) aufweist, der in der Öffnung (23) der ersten Stirnfläche (P3) beweglich vorgesehen ist und der mit einem Ventilsitz zusammenwirkt, der in dem zentralen strukturellen Element ausgebildet ist, so dass die Verbindung zwischen dem stromaufwärtsseitigen Bereich und dem stromabwärtsseitigen Bereich der Leitung (6) für die Abgase gesteuert wird.

Revendications

1. Module multifonctionnel (1) pour un moteur à combustion interne (E) d'un véhicule automobile, incorporant une partie d'un système de recirculation de gaz d'échappement du moteur et une partie d'un circuit de refroidissement du moteur, ledit module comprenant une unité de soupape EGR (3) pour réguler le flux de gaz d'échappement recirculé et un échangeur de chaleur (4) pour refroidir les gaz d'échappement recirculés, au moyen du liquide de refroidissement de moteur, en outre, dans lequel :

- ledit module multifonctionnel comprend un élément de structure central (2), avec un corps métallique ayant une face (P6) pour se fixer à une face d'extrémité de la culasse (T) du moteur (E), un tel corps ayant une forme allongée selon une direction qui est perpendiculaire à la direction longitudinale de la culasse, à l'état monté dudit module sur le moteur,

- un conduit (6) pour la circulation des gaz d'échappement et un conduit (7) pour la circulation du liquide de refroidissement de moteur sont formés à l'intérieur dudit corps métallique de l'élément de structure central (2), lesdits conduits (6, 7) s'étendant à partir d'une ouverture d'entrée (9) des gaz d'échappement et d'une ouverture d'entrée (8) du liquide de refroidissement, lesdites ouvertures d'entrée (8, 9) étant positionnées sur ladite face de fixation (P6) et communiquant respectivement avec le collecteur d'échappement de moteur et avec une chemise de liquide de refroidissement de la culasse,

- ledit conduit de gaz d'échappement (6) débouche dans une ouverture de sortie de gaz d'échappement (10) destinée à communiquer avec le collecteur d'admission de moteur, tandis que ledit conduit de liquide de refroidissement (7) débouche dans au moins une ouverture de sortie de liquide de refroidissement (11) à laquelle peut être associée une soupape thermostatique (19) pour commander une liaison au radiateur du système de refroidissement de moteur,

- ladite unité de soupape EGR (3) pour réguler le flux de gaz d'échappement recirculé est montée sur une première face d'extrémité (P3) dudit corps allongé de l'élément de structure central (2), et est interposée de manière fonctionnelle le long dudit conduit de gaz d'échappement (6),

- ledit échangeur de chaleur (4) pour le refroidissement des gaz d'échappement par le liquide de refroidissement est monté sur une deuxième face d'extrémité (P2) dudit corps allongé de l'élément de structure central (2), qui est opposée à ladite première face d'extrémité (P3) sur laquelle ladite unité de soupape EGR (3) est montée, ledit échangeur de chaleur (4) ayant des conduits internes (41, 43) en relation mutuelle d'échange de chaleur, qui sont respectivement interposés de manière fonctionnelle le long dudit conduit de gaz d'échappement (6) et dudit conduit de liquide de refroidissement (7),

- un conduit de dérivation (65) pour les gaz d'échappement est formé à l'intérieur dudit corps allongé de l'élément de structure central (2), à travers lequel les gaz d'échappement peuvent s'écouler vers ladite ouverture de sortie de gaz d'échappement (10) sans passer à travers ledit échangeur de chaleur (4),

- une soupape de dérivation (13) est interposée à l'intérieur dudit conduit de dérivation (65) qui est actionnée au moyen d'un actionneur à dépression (14) porté par ledit module multifonctionnel (1),

- ledit module multifonctionnel (1) étant caractérisé en ce que ladite unité de soupape EGR (3) est positionnée de manière fonctionnelle le long du conduit de gaz d'échappement (6) en amont dudit échangeur de chaleur (4), de manière à ce que, lorsque ladite unité de soupape EGR (3) est à l'état ouvert, les gaz d'échappement passent à travers ladite unité de soupape EGR (3), avant d'être refroidis dans l'échangeur de chaleur (4), et

- en ce que ledit actionneur à dépression (14) qui commande la soupape de dérivation (13) est agencé pour être actionné par une source de dépression externe au module (1), moyennant quoi ledit module est privé de toute source de dépression ou de tout réservoir à dépression.

2. Module multifonctionnel (1) selon la revendication 1, caractérisé en ce que ladite deuxième face d'extrémité (P2) du corps de l'élément de structure central (2) est entièrement occupée par ledit échangeur de chaleur (4).

3. Module multifonctionnel (1) selon la revendication 1, caractérisé en ce que ledit échangeur de chaleur est configuré de manière à ce que les gaz d'échappement qui passent à travers l'échangeur de chaleur suivent un chemin en forme de U.

4. Module multifonctionnel (1) selon la revendication 3, caractérisé en ce que le chemin en forme de U pour les gaz d'échappement à travers l'échangeur de chaleur (4) est défini par une première rangée de tubes ou de canaux plats (41) pour l'écoulement des gaz d'échappement dans une première direction, par une deuxième rangée de tubes ou de canaux plats (41) pour l'écoulement des gaz d'échappement dans une deuxième direction opposée à la première direction et par une chambre intermédiaire (44) qui relie les tubes ou les canaux plats de la première rangée aux tubes ou aux canaux plats de la deuxième rangée.

5. Module multifonctionnel (1) selon la revendication 4, caractérisé en ce que les tubes ou les canaux plats (41) de ladite deuxième rangée définissent une zone de section transversale de passage globale plus petite que la zone de section transversale de passage globale définie par les tubes ou les canaux plats (41) de la première rangée, de manière à empêcher une réduction de la vitesse des gaz d'échappement provoquée par la réduction de la densité due au refroidissement.

6. Module multifonctionnel (1) selon la revendication 1, caractérisé en ce que ledit conduit de refroidissement (7) comprend :

- une première partie de conduit (71) qui s'étend à travers le corps d'élément de structure central (2) à partir de ladite ouverture d'entrée (8) positionnée au niveau de ladite face de fixation (P6) jusqu'à une face opposée (P1) de l'élément de structure central (2), où se trouve ladite ouverture de sortie (11), à laquelle la soupape thermostatique (19) est associée ;

- une deuxième partie de conduit (71) qui se ramifie de la première partie de conduit (71) dans la direction de ladite première face d'extrémité (P3) de l'élément de structure central (2) auquel l'unité de soupape EGR (3) est associée et qui se termine dans une chambre (73) adjacente à ladite première face d'extrémité (P3) de l'élément de structure central (2) pour refroidir l'unité de soupape EGR (3), et

- une troisième partie de conduit (74) qui s'étend longitudinalement le long dudit élément de structure central (2) à partir de ladite chambre (73) jusqu'à une entrée (22) du liquide de refroidissement dans l'échangeur de chaleur (4),

- ledit échangeur de chaleur (4) ayant une sortie (42) pour le liquide de refroidissement destinée à être reliée à un élément externe du circuit de refroidissement de moteur, tel qu'un refroidisseur pour l'huile-moteur.

7. Module multifonctionnel selon la revendication 1, caractérisé en ce que ledit conduit de gaz d'échappement (6) comprend :

- une partie de conduit (60, 61) pour les gaz d'échappement, positionnée de manière fonctionnelle en amont de l'unité de soupape EGR (3) et qui s'étend à travers le corps de l'élément de structure central (2) à partir de ladite ouverture d'entrée (9) pour les gaz d'échappement positionnée sur ladite face de fixation (P6) de l'élément de structure central (2) jusqu'à ladite première face d'extrémité (P3) de l'élément de structure central (2),

- une partie de conduit (62, 63) pour les gaz d'échappement qui est positionnée de manière fonctionnelle en aval de l'unité de soupape EGR (3), et qui s'étend à travers le corps de l'élément de structure central (2) jusqu'à ladite deuxième face d'extrémité (P2) de l'élément de structure central (2) où elle débouche dans une entrée pour les gaz d'échappement dans l'échangeur de chaleur (4), la communication entre ladite partie amont et ladite partie aval du conduit de gaz d'échappement (6) étant commandée par ladite unité de soupape EGR (3),

- une partie de conduit terminale pour les gaz d'échappement formée dans ledit corps de l'élément de structure central (2), qui relie une sortie des gaz d'échappement depuis l'échangeur de chaleur (4) à ladite ouverture de sortie (10) des gaz d'échappement du module multifonctionnel (1),

- ledit conduit de dérivation (65) étant défini par un conduit formé dans le corps de l'élément de structure central (2) qui relie directement ladite partie de conduit (62, 63) pour les gaz d'échappement en aval de l'unité de soupape EGR (3) à ladite partie de conduit terminale pour les gaz d'échappement.

8. Module multifonctionnel (1) selon la revendication 7, caractérisé en ce que ladite partie de conduit (60, 61) pour les gaz d'échappement qui est positionnée de manière fonctionnelle en amont de l'unité de soupape EGR (3) débouche dans une ouverture (23) sur ladite première face d'extrémité (P3) du corps de l'élément de structure central (2) et en ce que ladite unité de soupape EGR (3) comprend un obturateur de soupape (8) qui est prévu de manière mobile dans ladite ouverture (23) de ladite première face d'extrémité (P3) et qui coopère avec un siège de soupape formé à l'intérieur dudit élément de structure central pour commander la communication entre les parties amont et aval du conduit (6) pour les gaz d'échappement.

Drawing