FR3060666A1 - COOLANT FLOW PIPE FOR INTERNAL COMBUSTION ENGINE OF MOTOR VEHICLE - Google Patents

Abstract

This passageway (28) for cooling fluid for an internal combustion engine (2) of a motor vehicle comprises a tubular portion (30) to allow the passage of a cooling liquid from a cooling circuit (6) of the engine (2), said tubular portion (30) having an upstream end (32) adapted to be connected to a first functional member of the motor (2), and a downstream end (34) opposed to the upstream end (32) and provided to be connected to a second functional member of the motor (2). The tubular portion (30) comprises at least one receiving orifice (52) adapted to receive at least one heating element of the cooling liquid.

Description

© Publication number: 3,060,666 (to be used only for reproduction orders) (© National registration number: 16 62596 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY

COURBEVOIE © Int Cl ⁸ : F 02 N 19/10 (2017.01), F 01 P 11/04, 5/00

A1 PATENT APPLICATION

(© Date of filing: 16.12.16. (© Applicant (s): RENAULT S.A.S Joint-stock company (© Priority: simplified - FR. @ Inventor (s): LACOUR MARC and DEBROIS OLI- VIER. (43) Date of public availability of the request: 22.06.18 Bulletin 18/25. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents (73) Holder (s): RENAULT S.A.S Société par actions sim- related: folded. ©) Extension request (s): © Agent (s): RENAULT SAS.

CONDUIT FOR COOLING LIQUID FOR INTERNAL COMBUSTION ENGINE OF MOTOR VEHICLE.

FR 3 060 666 - A1 \ 7 /) This coolant passage duct (28) for an internal combustion engine (2) of a motor vehicle comprises a tubular portion (30) to allow the passage of a coolant d 'a cooling circuit (6) of the engine (2), said tubular portion (30) comprising an upstream end (32) intended to be connected to a first functional member of the engine (2), and an opposite downstream end (34) at the upstream end (32) and intended to be connected to a second functional member of the motor (2).

The tubular portion (30) comprises at least one receiving orifice (52) capable of receiving at least one element for heating the coolant.

i

Coolant passage duct for an internal combustion engine of a motor vehicle

The present invention relates to the field of cooling circuits for an internal combustion engine, in particular for motor vehicles.

Conventionally, a motor vehicle comprising an internal combustion engine is provided with a cooling circuit intended to regulate the temperature of the engine. The temperature is lowered by the passage of a coolant, the circulation of which is generated by a pump. The liquid is conventionally called water but most of the time corresponds to a coolant such as brine.

Motor vehicles with an internal combustion engine are faced with ever-increasing demands to limit fuel consumption and pollutant emissions. To this end, such vehicles generally include an exhaust gas recirculation duct, also known by the Anglo-Saxon name "Exhaust Gas Recirculation" or under the abbreviation "EGR". The function of such a duct is to extract exhaust gases from the internal combustion engine in order to re-inject them into an intake duct of the engine. In this way, the recirculation duct makes it possible to limit fuel consumption and pollutant emissions.

This solution does not, however, bring full satisfaction. In particular, during a vehicle start-up phase, the internal combustion engine is generally cold, so that the recirculation duct cannot be opened immediately. Under these conditions, the vehicle consumes more fuel and emits more pollutants.

To overcome this drawback, boxes can be used comprising means for heating the coolant in the engine cooling circuit. The housing is connected to a first point of the cooling circuit via a first hose and to a second point of the cooling circuit via a second hose. In this way, the coolant circulating in the cooling circuit passes through the first hose, is heated as it passes through the housing, then joins the cooling circuit through the second hose. Due to the cooling liquid heating, the exhaust gas recirculation is activated more quickly.

Although such a solution is generally considered satisfactory, it continues to have certain drawbacks. In particular, the space generated by the housing and the two hoses makes it practically impossible to install such a housing in an engine compartment of a motor vehicle.

In view of the above, the invention aims to provide a cooling circuit component of an internal combustion engine overcoming the aforementioned drawbacks.

More particularly, the invention aims to allow the heating of the coolant while optimizing the heat exchange efficiency caused during heating, in order to limit fuel consumption and pollutant emissions, and by limiting the size generated within the engine compartment.

To this end, a coolant passage duct for an internal combustion engine of a motor vehicle is proposed comprising a tubular portion to allow the passage of a coolant from an engine cooling circuit, said tubular portion comprising an upstream end intended to be connected to a first functional member of the engine, and a downstream end opposite to the upstream end and provided to be connected to a second functional member of the engine.

According to a general characteristic of this conduit, the tubular portion comprises at least one receiving orifice capable of receiving at least one element for heating the cooling liquid.

Such a passage duct makes it possible to heat the coolant while limiting the space generated within the engine compartment. In addition, the coolant is heated near the engine so as to allow the engine to warm up more quickly. This improves the cold start conditions to enable activation of the exhaust gas recirculation faster. The heated passage duct also constitutes an additional heat source which helps to preheat a charge air cooler. These effects notably result in better treatment of pollutants and lower fuel consumption.

According to one embodiment, the first functional member of the engine is an oil cooler and / or the second functional member of the engine is a cylinder block of the engine or a coolant pump.

Having the passage duct provided with a heating element between the oil cooler and the coolant pump, and in particular just upstream of the coolant pump, makes it possible in particular to circulate the liquid hot cooling in the water pump, which is close to the engine. This further warms the exhaust gases to open the exhaust gas recirculation valve even earlier and further warm the charge air cooler.

Advantageously, the passage duct consists of a single piece produced by molding, preferably made of aluminum.

By making the passage conduit in this way, the manufacturing costs of the conduit and the costs of integrating the cooling circuit within the internal combustion engine are reduced, and the thermal conductivity of the passage conduit is increased.

According to another embodiment, the passage duct comprises at least four receiving orifices each capable of receiving a glow plug.

As will be explained below, the use of four glow plugs is particularly advantageous in that it allows the engine load to be increased sufficiently during regeneration of the particle filter. Glow plugs are also known by the name of immersion heaters.

Preferably, said at least four receiving orifices are staggered.

It is also possible to provide a branch intended to be connected to an air heater of the cooling circuit.

In an advantageous embodiment, said at least one receiving orifice comprises a cylindrical bore of small diameter extending outwards from an internal wall of the tubular portion, and a cylindrical bore of large diameter extending towards the inside from a wall located outside the tubular portion, the two cylindrical bores being coaxial, the two cylindrical bores being connected by a frustoconical bore whose generatrixes form an angle between 58 ° and 66 ° with the common axial direction of said two cylindrical bores.

Such a design of said at least one receiving orifice allows easy installation of a glow plug, while maintaining a reinforced seal of the coolant passage duct.

In a particular embodiment, the passage duct comprises a lug for attachment to a cylinder block of the engine.

Such an ear makes it possible to prevent the transmission of vibrations from the cylinder block to the passage duct.

According to another aspect, an internal combustion engine for a motor vehicle is proposed comprising a cylinder block, a cooling circuit, a first functional member, a second functional member and a coolant passage duct as defined above.

In one embodiment, the engine comprises a coolant pump delimited by a pump casing, said pump casing being at least partially formed by a portion of the cylinder block.

Such an embodiment is in particular advantageous in that the cooling liquid heated by said at least one heating element is directly in contact with the cylinder blocks. As a result, heat losses are minimized during the transfer of energy from the heated coolant to the internal combustion engine. In this way, by providing a minimum of energy, the temperature rise of the internal combustion engine is further increased so as to further limit fuel consumption and pollutant emissions.

Other objects, characteristics and advantages of the invention will appear on reading the following description, given solely by way of nonlimiting example, and made with reference to the appended drawings in which:

FIG. 1 schematically represents a cooling circuit of an internal combustion engine according to an exemplary embodiment of the invention,

FIG. 2 is an isometric view of a passage for the cooling circuit in FIG. 1, and

FIG. 3 is a sectional view of an orifice for receiving the passage duct of FIG. 2.

FIG. 1 shows an internal combustion engine 2. The engine 2 is intended to be incorporated in a motor vehicle. The engine 2 can be a spark-ignition engine or a compression-ignition engine. The engine 2 notably comprises at least one cylinder (not shown) inside which combustion takes place. The cylinder is delimited by a cylinder block 4 schematically represented in FIG. 1 by the rectangular frame surrounding the combustion engine 2.

The engine 2 is associated with a cooling circuit 6. The function of the cooling circuit 6 is to regulate the temperature of the engine 2.

As will be detailed later, the cooling circuit 6 comprises a plurality of members, some of which cooperate directly with the engine 2. These members are designated in the present application as being functional members of the engine.

The cooling circuit 6 includes a coolant pump 8, also known by the name of water pump. The pump 8 has the function of activating the circulation of the coolant in the circuit 6 passing through the engine 2 before cooling the latter. The pump 8 is delimited by a pump casing 10, schematically represented in FIG. 1 by the rectangular frame surrounding the pump 8. In a manner known per se, the pump 8 is driven directly by the internal combustion engine 2. The pump 8 is thus a functional member of engine 2.

As shown diagrammatically in FIG. 1, the compression chamber of the pump 8 is only partially delimited by the pump casing 10. To delimit the compression chamber of the pump 8, the pump casing 10 is fixed on the cylinder block 4. In other words, the compression chamber of the pump 8 is partially bounded by the pump block 10 and partially by the cylinder block 4.

The cooling circuit 6 also includes an air heater 12. The function of the air heater 12 is to allow the passenger compartment of the motor vehicle to be heated while cooling the coolant in circuit 6.

The circuit 6 further comprises a radiator 14. The radiator 14 is provided in order to cool the cooling liquid by convection. To this end, the radiator 14 can be placed just behind the grille of the motor vehicle, so as to be able to effectively cool the coolant circulating in the circuit 6.

The circuit 6 further comprises an oil cooler 16. The oil cooler 16 is used to regulate the temperature of the engine oil 2. The cooler 16 is then a functional member of the engine 2. Furthermore, the cooler oil 16 is directly attached to the cylinder block 4 of the engine 2.

The cooling circuit 6 comprises a plurality of conduits for the passage of the coolant between the members

8, 12, 14 and 16. In particular, the circuit 6 comprises a first common pipe 18 connecting a water outlet housing 17 to a bifurcation point (not referenced). At this bifurcation point, the pipe 18 divides into a first sub-pipe 20 and a second sub-pipe 22. The sub-pipe 20 connects the bifurcation point to the air heater 12. The sub-pipe 22 connects the bifurcation point at the radiator 14.

The water outlet box 17 comprises an inlet opening communicating with the water circuit of a cylinder head 5 and an outlet placed in fluid communication with the first common pipe 18.

The cooling circuit also comprises a second pipe 24 connecting the radiator 14 to the oil cooler 16. The cooling circuit 6 also includes a third pipe 26 connected to the air heater 12.

The direction of circulation of the coolant in the pipes 18 to 26 is schematically represented by FIG. 1 by arrows. The water pump 8 is arranged upstream of the engine 2, in the direction of flow of the coolant in the cooling circuit 6. The pump 8 allows water to flow through the cylinder block 4 and the cylinder head 5 of engine 2. After having circulated through cylinder head 5 of engine 2, the coolant leaves the cylinder head 5 through the outlet box 17 to which the pipe 18 is connected. In other words, the coolant cooling passing through the air heater 12 leaves the water outlet housing 17 through the pipe 18, passes the bifurcation point, takes the pipe 20, crosses the air heater 12 then takes the pipe 26. The coolant passing through the radiator 14 and the cooler 16 leaves the water outlet housing 17 via the pipe 18, passes the bifurcation point, takes the pipe 22, crosses the radiator 14, takes the pipe 24 and reaches the cooler 16.

The cooling circuit 6 further comprises a passage duct 28, schematically represented in FIG. 1 and shown in isometric view in FIG. 2. One function of the passage duct 28 is to connect the oil cooler 16, the pump coolant 8 and the pipe 26 coming from the air heater 12.

In an alternative embodiment not shown, the passage duct 28 allows connection only of the oil cooler 16 to the coolant pump 8, in particular via an interface of the cylinder block 4 intended to receive the coolant pump 8. The cooling circuit then includes another tapping point for line 26.

Referring to Figure 2, the passage duct 28 comprises a tubular portion 30. In the illustrated embodiment, the portion 30 is of angled shape to further adapt to the environment of the engine compartment. However, it is not going beyond the scope of the invention to envisage a different shape from the tubular portion 30. Furthermore, in the example illustrated, the tubular portion 30 has a substantially constant circular section.

The tubular portion 30 comprises a first upstream end 32 and a second downstream end 34. Each end 32, 34 is provided with a stop flange 36 and an annular groove 38.

The upstream end 32 is configured to be able to be directly connected to an outlet (not shown) of the oil cooler 16. More particularly, the end 32 is inserted into a cylindrical opening provided in the oil cooler 16, such so that the flange 36 abuts against a wall of the oil cooler 16. An annular seal can be inserted in the groove 38, so as to provide a sufficient seal for the connection of the passage duct 28 on the oil cooler 16 .

Similarly, the downstream end 34 is configured to be able to be directly connected to an inlet (not shown) of the cylinder blocks 4 which can partially define the body of the coolant pump 8. The end 34 is in this case inserted into a cylindrical opening provided on the cylinder block 4, the flange 36 abutting against a wall of the pump 8, an annular seal being inserted in the groove 38.

The duct 28 may also have a branch 40. The branch 40 is pierced directly on the tubular portion 30 of the passage duct 28. The branch 40 has an end 42 forming a cylindrical sleeve 44 for connection with the duct 26. Like the ends 32 and 34, the end 42 has a stop flange 46.

Thanks to the ends 32, 34 and 42, the passage duct 28 is directly connected to the oil cooler 16 and to the cylinder cylinders 4, and indirectly connected to the air heater 12 via the pipe 26. By these three connections , the passage duct 28 is isostatically fixed relative to the cylinder block 4.

In the exemplary embodiment illustrated, the passage duct 28 further comprises a fixing lug 48. Although, in the example illustrated in FIG. 2, the lug 48 extends from the branch 40, the lug 48 can extend from a different portion of the passage duct 28, for example the tubular portion 30.

The fixing lug 48 is provided to allow fixing of the passage duct 28 on the cylinder block 4. The fixing lug 48 makes it possible to fix the duct 28 in a simple manner, for example by means of a screw cooperating with a corresponding threaded bore made in the cylinder block 4. The fixing lug 48 makes it possible to prevent the transmission of vibrations from the cylinder blocks 4 to the passage duct 28. However, it is not going beyond the ambit of the invention to envisage a passage duct 28 devoid of such a fixing lug.

As shown in FIG. 2, the passage duct 28 further comprises four local protrusions 50 extending from the tubular portion 30. Each protrusion extends substantially in radial projection out of the tubular portion 30. A sectional view of a local protuberance 50 is shown in FIG. 3. Each protuberance 50 is intended to receive an element for heating the coolant circulating in the passage duct 28. In the present case, the heating means is an electric plug ίο preheating (not shown). In other words, four electric glow plugs are intended to be respectively mounted in the four local protrusions 50.

In order to efficiently heat the coolant while limiting the space requirement, we prefer glow plugs supplied with electric power as needed. For example, the electrical power is between 250 W and 350 W for each spark plug, and even more preferably substantially 300 W each. Using four such glow plugs, an energy of the order of 1200 W must be supplied to the plugs to heat the coolant. The presence of an electric consumer needing 1,200 W makes it possible to increase the engine load during regeneration of the particulate filter. This results in greater efficiency of operation of this filter and therefore a reduction in pollutant emissions.

The four protrusions 50 extend from the tubular portion 30 substantially in the same direction. Each protuberance 50 comprises a front wall 49 opposite the tubular portion 30.

With reference to FIG. 3, a local protuberance 50 includes a reception orifice 52 capable of receiving a glow plug. More particularly, the receiving orifice 52 is through. In other words, the receiving orifice 52 extends from an internal wall 51 of the tubular portion 30, passes through the tubular portion 30 over its entire thickness, passes through the local protuberance 50 and opens out to the outside of the portion tubular 30 and the protuberance 50, at the level of the wall 49. The reception orifice 52 has a generally axisymmetric shape around an axis of cylindricity 53 and consists of several successive cylindrical and / or frustoconical bores around the axis 53. In the example illustrated, axis 53 coincides with the direction in which the corresponding protuberance 50 extends.

More particularly, the receiving orifice 52 comprises a first cylindrical bore 54 adjacent to the bottom wall 51. The axis of cylindricity of the bore 54 coincides with the axis 53. Opposite the interior wall 51, l the bore 54 is extended by a first frustoconical bore 56. The axis of cylindricity of the bore 56 also coincides with the axis 53. The frustoconical bore 56 has the shape of a cylinder trunk whose generatrices form an angle a with respect to the axis 53. In the example illustrated, the angle a is between 58 ° and 66 °, preferably between 60 ° and 64 ° and even more preferably is substantially equal to 60 °.

Opposite the first cylindrical bore 54, the frustoconical bore 56 is extended by a second cylindrical bore 58. The axis of cylindricity of the bore 58 coincides with the axis 53. The bore 58 has a diameter greater than that of the bore 54. In addition, the bore 58 comprises a thread 59 capable of cooperating with a corresponding thread made on a cylindrical wall complementary to the glow plug. Opposite the first frustoconical bore 56, the cylindrical bore 58 is extended by a second frustoconical bore 60. The frustoconical bore 60 forms a cylinder trunk whose generatrices form an angle β with the axis 53. In the illustrated example, the angle β is substantially equal to 45 °.

Thanks to this arrangement of the receiving orifice 52, a glow plug (not shown) can be introduced into the bores 60, 58, 56 and 54. The bore 60 provides an inlet chamfer of the orifice 52 in order to facilitate the insertion of the glow plug. Preferably, the glow plug has a shoulder of design complementary to that of the frustoconical bore 56. In this way, the shoulder of the glow plug comes into abutment against the frustoconical bore 56. This thus reinforces the seal supplied at the level of the reception orifice 52 and of the glow plug vis-à-vis the coolant circulating in the passage duct 28. In particular, the seal is reinforced thanks to the optimal shape of the bore 56 and the value of the angle a formed by its generatrices. In addition, thanks to the thread made on the bore 58, the glow plug is simply and reliably fixed in the receiving orifice 52.

Thus, in the example illustrated, the reception orifices 52 extend between the internal wall 51 of the conduit 28 and the front wall 49 of the protrusions 50. This arrangement is particularly advantageous in that it allows reliable and sealed installation of the glow plugs. It is not, however, outside the scope of the invention to envisage different receiving orifices, for example extending between the internal wall 51 and an external wall (not referenced) of the tubular portion 30. In such a variant, the thickness of the tubular portion 30 must be greater if one wishes to obtain a reliable and sealed installation. The embodiment illustrated in the figures, comprising in particular the orifices 52 partially located in the local protrusions 50, thus enables material to be saved and the size and mass of the passage duct 28 to be limited.

Again with reference to FIG. 2, the four local protrusions 50 and the four receiving orifices 52 are disposed approximately in staggered rows relative to each other. Such an arrangement is particularly advantageous because it allows the glow plugs to be supplied with an electric cable (not shown) allowing the circulation of a power current, limiting the space caused by the presence of the electric cable.

Furthermore, the design of the passage conduit 28 in a single piece produced by molding is advantageous in that it facilitates the production of the passage conduit 28, so as to limit the costs, in that it reduces the risks of leakage. of the cooling circuit and in that it increases the thermal conductivity through the duct 28. In this way, when the coolant of the circuit 6 is heated during the temperature rise phase of the engine 2, losses are minimized thermal caused during the transfer of heat from the coolant to the engine 2. In the example illustrated, this effect is further accentuated by choosing an appropriate material for molding the passage duct 28, that is to say a material with high thermal conductivity such as for example aluminum.

In view of the above, the passage duct 28 allows the coolant 5 to pass through the cooling circuit 6 in a simple and economical manner, so as to improve the operation of the engine during the temperature rise and regeneration phases. of the particulate filter, while optimizing the energy consumption of electronic components such as glow plugs and limiting the space caused in the engine compartment.

In particular, the invention makes it possible to implement recirculation of the exhaust gases earlier, to activate more quickly an engine charge air cooler and to increase the engine load in an optimal manner during regeneration phases of the particulate filter.

Claims (10)

1. Coolant passage duct (28) for an internal combustion engine (2) of a motor vehicle, comprising a tubular portion (30) for allowing the passage of a coolant from a cooling circuit (6) of the motor (2), said tubular portion (30) comprising an upstream end (32) intended to be connected to a first functional member of the motor (2), and a downstream end (34) opposite the upstream end (32) and intended to be connected to a second functional member of the engine (2), characterized in that the tubular portion (30) comprises at least one receiving orifice (52) capable of receiving at least one element for heating the coolant. 2. passage duct (28) according to claim 1, in which the first functional member of the engine is an oil cooler (16) and / or in which the second functional member of the engine is a cylinder block (4) of the engine or coolant pump (8). 3. Passage duct (28) according to claim 1 or 2, characterized in that it consists of a single piece produced by molding, preferably made of aluminum. 4. Passage duct (28) according to any one of claims 1 to 3, comprising at least four receiving orifices (52) each capable of receiving a glow plug. 5. Passage duct (28) according to claim 4, wherein said at least four receiving orifices (52) are staggered. 6. Passage duct (28) according to any one of claims 1 to 5, comprising a branch (40) intended to be connected to an air heater (12) of the cooling circuit (6) of the engine (2). 7. passage conduit (28) according to any one of claims 1 to 6, wherein said at least one receiving orifice (52) comprises a cylindrical bore (54) of small diameter extending outward from a inner wall (51) of the tubular portion (30), and a cylindrical bore (58) of large diameter extending inward from a wall (49) located outside of the tubular portion (30), two cylindrical bores (54, 58) being coaxial, the two cylindrical bores (54, 58) being connected by a frustoconical bore (56) whose generatrices form an angle (a) between 58 ° and 66 ° with the axial direction ( 53) of said two cylindrical bores (54, 58). 8. Passage duct (26) according to any one of claims 1 to 7, comprising a fixing lug (48) to a cylinder block (4) of the engine. 9. Internal combustion engine (2) for a motor vehicle comprising a cylinder block (4), a cooling circuit (6), a first functional member, a second functional member and a coolant passage duct (28) according to any one of claims 1 to 8. 10. Engine (2) according to claim 9, comprising a coolant pump (8) delimited by a pump housing (10), said pump housing (10) being at least partially formed by a portion of the cylinder housing (4). 1/2