FR3060666B1 - 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

Coolant passage conduit 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.

Typically, a motor vehicle comprising an internal combustion engine is provided with a cooling circuit for regulating the temperature of the engine. The lowering of the temperature is done by the passage of a coolant whose circulation is generated by a pump. The liquid is conventionally called water but is mostly a brine type coolant.

Motor vehicles with an internal combustion engine face ever-increasing demands to limit fuel consumption and pollutant emissions. For this purpose, such vehicles generally comprise an exhaust gas recirculation duct, also known by the English name "Exhaust Gas Recirculation" or the abbreviation "EGR". Such a duct has the function of withdrawing exhaust gases at the outlet of the internal combustion engine for reinjecting them into an intake duct of the engine. In this way, the recirculation duct helps to limit fuel consumption and pollutant emissions.

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

To overcome this drawback, it is possible to use housings comprising means for heating the cooling liquid of the engine cooling circuit. The housing is connected to a first point of the cooling circuit via a first hose and at a second point of the cooling circuit via a second hose. In this way, the coolant flowing through the cooling circuit passes through the first hose, is heated as it passes through the housing, and then rejoins the cooling circuit through the second hose. Due to the heating of the coolant, the recirculation of the exhaust gas is activated more quickly.

Although such a solution is generally considered satisfactory, it still has certain disadvantages. In particular, the space generated by the housing and the two hoses makes it virtually impossible to install such a housing in a motor vehicle engine compartment.

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

More particularly, the invention aims to allow the heating of the coolant while optimizing the heat exchange efficiency caused during heating, to limit fuel consumption and pollutant emissions, and limiting congestion generated within the engine compartment. For this purpose, it is proposed a coolant passageway for a motor vehicle internal combustion engine comprising a tubular portion to allow the passage of a cooling liquid from a cooling circuit of the engine, said tubular portion comprising an upstream end intended to be connected to a first functional member of the engine, and a downstream end opposite the upstream end and intended 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 adapted to receive at least one heating element of the cooling liquid.

Ein such conduit passage to heat the coolant while limiting the space generated in the engine compartment. In addition, the coolant is heated near the engine so as to allow a temperature rise of the engine faster. This improves the cold start conditions to enable faster activation of the exhaust gas recirculation. The heating passage duct further provides an additional source of heat that helps warm up a charge air cooler with anticipation. In particular, these effects result in better treatment of pollutants and lower fuel consumption.

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

Providing the passageway with a heating element between the oil cooler and the coolant pump, and in particular just upstream of the coolant pump, allows in particular to circulate the liquid. Hot cooling in the water pump, which is close to the engine. This further warms the exhaust gas to open the exhaust gas recirculation valve even earlier and further heat up the charge air cooler.

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

By realizing the passage duct in this way, the duct fabrication costs and integration costs of the cooling circuit within the internal combustion engine are reduced, and the thermal conductivity of the passage duct is increased.

According to another embodiment, the passage conduit comprises at least four receiving ports each adapted to receive a glow plug.

As will be explained later, the use of four glow plugs is particularly advantageous in that it allows to increase sufficiently the engine load during regeneration of the particulate filter. Glow plugs are also known as immersion heaters.

Preferably, said at least four receiving orifices are arranged in staggered rows.

It can further provide a branch intended to be connected to a heater of the cooling circuit.

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

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

In a particular embodiment, the passage duct comprises an attachment lug to a crankcase of the engine.

Such an ear makes it possible to prevent the transmission of the vibrations of the crankcase to the passage duct.

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

In one embodiment, the engine comprises a coolant pump defined by a pump housing, said pump housing being at least partially formed by a portion of the crankcase.

Such an embodiment is particularly advantageous in that the cooling liquid heated by said at least one heating element is directly in contact with the crankcase. As a result, thermal 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, features and advantages of the invention will become apparent on reading the following description, given solely by way of nonlimiting example, and with reference to the appended drawings, in which: FIG. 1 schematically represents a circuit of FIG. cooling an internal combustion engine according to an exemplary embodiment of the invention, - Figure 2 is an isometric view of a passage duct of the cooling circuit Figure 1, and - Figure 3 is a sectional view of a receiving orifice of the passage duct of FIG.

There is shown in Figure 1 an internal combustion engine 2. The engine 2 is intended to be incorporated in a motor vehicle. The engine 2 may be a spark ignition engine or a compression ignition engine. The engine 2 comprises in particular at least one cylinder (not shown) inside which the 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 bodies are designated in this application as being functional members of the engine.

The cooling circuit 6 comprises a coolant pump 8, also known as a water pump. The function of the pump 8 is to actuate 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 organ of the engine 2.

As is diagrammatically shown in FIG. 1, the compression chamber of the pump 8 is only partially delimited by the pump casing 10. In order to delimit the compression chamber of the pump 8, the pump casing 10 is fixed on 4. In other words, the compression chamber of the pump 8 is partially defined by the pump housing 10 and partially by the crankcase 4.

The cooling circuit 6 further comprises a heater 12. The function of the heater 12 is to allow the heating of the passenger compartment of the motor vehicle while cooling the cooling liquid of the circuit 6.

The circuit 6 further comprises a radiator 14. The radiator 14 is provided to cool the cooling liquid by convection. For this purpose, the radiator 14 can be arranged just behind the radiator grille of the motor vehicle, so that the coolant circulating in the circuit 6 can be effectively cooled.

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. In addition, the cooler oil 16 is directly attached to the crankcase 4 of the engine 2.

The cooling circuit 6 comprises a plurality of passages for passing the cooling liquid between the members 8, 12, 14 and 16. In particular, the circuit 6 comprises a first common conduit 18 connecting a water outlet housing 17 to a bifurcation point (not referenced). At this bifurcation point, the pipe 18 is divided into a first sub-pipe 20 and a second sub-pipe 22. The sub-pipe 20 connects the bifurcation point to the heater 12. The sub-pipe 22 connects the bifurcation point to the radiator 14.

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

The direction of circulation of the coolant in the lines 18 to 26 is schematically represented in 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 a flow of water through the crankcase 4 and the cylinder head 5 of the engine 2. After having passed through the cylinder head 5 of the engine 2, the coolant exits the cylinder head 5 through the outlet housing 17 to which the pipe 18 is connected. In other words, the liquid of cooling passing through the heater 12 out of the water outlet housing 17 through the pipe 18, passes the bifurcation point, borrows the pipe 20 passes through the heater 12 and then takes the pipe 26. The coolant passing through the radiator 14 and the cooler 16 leaves the water outlet housing 17 through the pipe 18, passes the bifurcation point, takes the pipe 22, passes through the radiator 14, takes the pipe 24 and reaches the cooler 16.

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

In an alternative embodiment, not shown, the passage duct 28 allows a 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 comprises another stitching point for the pipe 26.

With reference to FIG. 2, the passage duct 28 comprises a tubular portion 30. In the exemplary embodiment illustrated, the portion 30 is of bent shape to adapt more to the environment of the engine compartment. However, it is not beyond the scope of the invention to envisage a different shape of the tubular portion 30. Furthermore, in the example shown, the tubular portion 30 has a substantially constant circular section.

The tubular portion 30 includes a first upstream end 32 and a second downstream end 34. Each end 32, 34 is provided with an abutment flange 36 and an annular groove 38. The upstream end 32 is configured 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 in the oil cooler 16, so that the flange 36 abuts against a wall of the oil cooler 16. An annular seal can be inserted into the groove 38 , so as to provide a sufficient seal of the connection of the passage duct 28 on the oil cooler 16.

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

The duct 28 may further comprise a branch 40. The branch 40 is stitched directly onto the tubular portion 30 of the passage duct 28. The branch 40 comprises an end 42 forming a cylindrical sleeve 44 for connection with the duct 26. As 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 block 4, and indirectly connected to the heater 12 via the duct 26. three connections, the passage duct 28 is fixed isostatically with respect to the crankcase 4.

In the exemplary embodiment illustrated, the passage duct 28 further includes an attachment lug 48. Although, in the example illustrated in FIG. 2, the lug 48 extends from the branch 40, the ear 48 may extend from a different portion of the passage conduit 28, for example the tubular portion 30. The attachment lug 48 is provided to allow attachment of the passage conduit 28 on the crankcase 4. The ear of Fixing 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 crankcase 4. The attachment lug 48 makes it possible to prevent the transmission of the crankcase vibrations. -cylinders 4 to the passage conduit 28. However, it is not beyond the scope of the invention to envisage a passage conduit 28 without such a fixing lug.

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

In order to effectively heat the coolant while limiting the space requirement, preheating glow plugs powered with electrical power will be preferred as needed. For example, the electrical power is between 250 W and 350 W for each candle, and even more preferably of substantially 300 W each. By using four glow plugs of this type, an energy of about 1200 W must be provided to the spark plugs to implement the heating of the coolant. The presence of an electrical consumer requiring 1,200 W makes it possible to increase the motor load during regenerations of the particulate filter. This results in greater efficiency in the operation of this filter and therefore a reduction in pollutant emissions.

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

Referring to Figure 3, a local protuberance 50 has a receiving port 52 adapted to receive a glow plug. More particularly, the receiving orifice 52 is through. In other words, the receiving orifice 52 extends from an inner 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 of the portion tubular 30 and the protuberance 50, at the wall 49. The receiving orifice 52 has a generally axisymmetrical shape about a cylindrical axis 53 and consists of several successive cylindrical and / or frustoconical bores around the axis 53. In the example shown, the axis 53 coincides with the direction in which extends the corresponding protuberance 50.

More particularly, the receiving orifice 52 comprises a first cylindrical bore 54 adjacent to the lower wall 51. The axis of cylindricity of the bore 54 coincides with the axis 53. Opposite the inner wall 51, 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 relative 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 adapted to cooperate with a corresponding thread 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. illustrated example, the angle β is substantially equal to 45 °.

With this arrangement of the receiving port 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 to to facilitate the insertion of the glow plug. Preferably, the glow plug has a design shoulder complementary to that of the frustoconical bore 56. In this manner, the shoulder of the glow plug abuts against the frustoconical bore 56. The sealing is thus enhanced. provided at the receiving orifice 52 and the glow plug vis-à-vis the coolant circulating in the passage conduit 28. In particular, the seal is enhanced through the optimal shape of the bore 56 and the value of the angle formed by its generators. In addition, thanks to the threading on the bore 58, the glow plug is simply and reliably fixed in the receiving orifice 52.

Thus, in the illustrated example, the receiving orifices 52 extend between the inner wall 51 of the duct 28 and the front wall 49 of the protuberances 50. This arrangement is particularly advantageous in that it allows a reliable and watertight installation of glow plugs. However, it is not beyond the scope of the invention to envisage different receiving orifices, for example extending between the inner wall 51 and an outer wall (not referenced) of the tubular portion 30. In such a variant, the The thickness of the tubular portion 30 must be greater if it is desired to obtain a reliable and sealed installation. The embodiment illustrated in the figures, comprising in particular the orifices 52 partially located in the local protuberances 50, thus saves material and limits the bulk and mass of the passage duct 28.

Referring again to FIG. 2, the four local protuberances 50 and the four receiving orifices 52 are arranged approximately staggered with respect to one another. Such an arrangement is particularly advantageous because it allows the supply of glow plugs with an electric cable (not shown) for the circulation of a power current, limiting the size caused by the presence of the electric cable.

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

In view of the foregoing, the passage duct 28 makes it possible to pass the cooling liquid of the cooling circuit 6 in a simple and economical manner, so as to improve the operation of the engine during the phases of temperature rise and regeneration of the engine. particulate filter, while optimizing the energy consumption of electronic components such as glow plugs and limiting the space requirement in the engine compartment.

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

Claims (9)

A coolant passageway (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). the motor (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) opposite to the upstream end (32) and adapted 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) adapted to receive at least one heating element of the coolant, said passage duct (28) comprising a branch (40) intended to be connected to a heater (12) of the cooling circuit (6) of the motor (2). The passage duct (28) according to claim 1, wherein the first functional member of the engine is an oil cooler (16) and / or wherein the second functional member of the engine is a cylinder block (4) of the engine or a coolant pump (8). 3. conduit (28) according to claim 1 or 2, characterized in that it consists of a single piece made by molding, preferably aluminum. 4. passage duct (28) according to any one of claims 1 to 3, comprising at least four receiving ports (52) each adapted to receive a glow plug. The passage conduit (28) of claim 4, wherein said at least four receiving ports (52) are staggered. The passageway (28) according to any one of claims 1 to 5, wherein said at least one receiving orifice (52) comprises a cylindrical bore (54) of small diameter extending outwardly from a inner wall (51) of the tubular portion (30), and a large diameter cylindrical bore (58) extending inwardly from a wall (49) outside the tubular portion (30), the 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). 7. A passage duct (26) according to any one of claims 1 to 6, comprising an attachment lug (48) to a crankcase (4) of the engine. 8. 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 passage for passage (28) of coolant. according to any one of claims 1 to 7. 9. Motor (2) according to claim 8, comprising a coolant pump (8) defined by a pump housing (10), said pump housing (10) being at least partially formed by a portion of the crankcase (4).