FR2860833A1 - Cooling circuit for internal combustion engine of motor vehicle, has unit managing coolant flow, and three distinct passages including respective inlets and outlets to permit independent circulation of coolant through each passage - Google Patents

Abstract

The circuit has a management unit e.g. thermostat, managing coolant e.g. water, flow across a cylinder head (1), a cylinder case (6) or thermal exchange units (13, 14). Two passages circulate the coolant in the head, and a third passage circulates the coolant in the case. The passages are distinct and have respective inlets (2a, 3a, 6a) and outlets (2b, 3b, 6b) to permit independent circulation of the coolant through each passage.

Description

Cooling circuit of an internal combustion engine consisting of

  minus three cooling passages.

  The invention relates to a cooling circuit of an internal combustion engine.

  The invention relates more particularly to a cooling circuit for an engine consisting of at least three cooling passages, the passages being separate and intended for the circulation of a coolant.

  Document DE4222801 teaches a cooling device of an internal combustion engine. The engine comprises a cylinder head and a cylinder block, a technical feature essentially resides in that the cylinder head comprises two passages dedicated to a circulation of a coolant. The first passage disposed in the upper part of the cylinder head comprises at each of these ends, an inlet and an outlet useful for the flow of the fluid. The second passage, arranged in the lower part, communicates with a passage located in the cylinder block, so that the engine comprises two separate cooling passages.

  It is thus known that a cooling circuit of an internal combustion engine may comprise two separate passages, dedicated to the cooling of the engine. Preferably, the first passage is intended for cooling the upper part of the cylinder head, such as the part near the exhaust ducts, the second passage being for its part intended for cooling the cylinder block and the lower part of the cylinder head. The lower part of the breech is essentially the close part of the tablature.

  Advantageously, this type of cooling circuit allows a rapid temperature rise of the cylinder block so as to significantly reduce the friction of the piston rings on the shirts. Thus, during the engine warm-up phase, the flow of water through the second passage is interrupted. Only the circulation of water continues through the first passage of the cylinder head so that the circulation of the coolant through the first passage and then through a heater can quickly warm up the passenger compartment of the vehicle.

  The applicant has found that the heat exchange between the upper part of the cylinder head and the coolant flowing in the first passage generates a reduction in the temperature of the exhaust gas. Indeed, the first passage disposed in the upper part is adjacent to the exhaust ducts through which circulate the hot gases exiting the combustion chamber. It thus seems antagonistic to be able to satisfy both rapid heating of the passenger compartment and a rapid rise in temperature of the gases flowing through the exhaust ducts.

  Therefore, the technique used in the engines provided with two cooling passages, as described in the patent DE4222801, does not allow, during the temperature rise phase of the engine, to reconcile both an optimal reduction of pollution generated by the operation of the engine and a rapid rise in the temperature of the passenger compartment of the vehicle. Indeed, the pollution control system disposed downstream of the exhaust ducts of the cylinder head generally operates optimally with a high temperature of the exhaust gas. The circulation of the heat transfer fluid in the upper part of the cylinder head then reduces the efficiency of the pollution control system.

  A simple solution would be to cancel the circulation of the coolant in the first passage of the cylinder head, thus generating an absence of the rise in temperature of the coolant. The coolant present in the heater for the heating of the passenger compartment is not carrying heat energy, the heating of the passenger compartment can not then be done by recovering the thermal energy produced by the engine. It would then be necessary to add to the conventional heating system an expensive heating device, such as an electric heater or a heat pump.

  Another solution would be to recover thermal energy through the cylinder block. It is known that the coefficient of adhesion between the piston rings and the jackets changes with the temperature change of the cylinder block so as to reach high values when the engine has not reached its nominal operating temperature. It is therefore not possible to recover the thermal energy contained in the cylinder block so as not to reduce the speed of temperature rise of the engine. Therefore, during the engine warm-up phase, the circulation of the coolant through the cooling passage of the cylinder block should preferably remain interrupted.

  An object of the present invention is to provide a cooling circuit for an internal combustion engine comprising at least one cylinder head, a cylinder block, the circuit comprising heat exchange means, a means for driving a coolant and the less a means for managing the flow of the coolant through the cylinder head, the cylinder block or heat exchange means, overcoming all or part of the disadvantages of the prior art noted above.

  The present invention relates to a cooling circuit characterized in that it comprises essentially at least three independent passages dedicated to the cooling of the engine, the first and second passages being arranged in the cylinder head, the third passage being arranged in the cylinder block, the passages being distinct and comprising at least one inlet and one outlet so as to allow independent circulation of the heat transfer fluid through each of the passages of the cylinder head and the cylinder block.

  Furthermore, the invention may comprise one or more of the following features: the means for managing the flow of the coolant act independently on each of the first, second and third cooling passages of the engine, the first and second cooling passages being arranged parallel to each other in the cylinder head, - the first passage is a cooling fluid core disposed near the exhaust ducts of the engine cylinder head to recover the thermal energy from the gases leaving the combustion chamber, the second passage is for its part a cooling fluid core disposed near the base of the engine cylinder head to recover the thermal energy produced by the combustion and dissipated by thermal conduction at the base the means for managing the flow of the fluid are connected to the inlets and outlets thereby enabling the circulating coolant to in at least one of the cylinder head and / or cylinder block passages in series or in parallel, the direction of flow of the coolant being opposable in at least two of the engine cooling passages, the flow of the fluid is performed only by the second passage of the cylinder head so as to recover the heat energy at the base of the cylinder head to heat a passenger compartment of a vehicle, and to allow a rapid rise in temperature of a system of depollution connected to the exhaust ducts and the cylinder block, the means for managing the flow of the heat transfer fluid allow a circulation of the fluid through at least one heat exchanger and / or a bypass branch, a reading means the temperature of the coolant being preferably disposed at the outlet of a passage passing through the cylinder head, such as the second passage, so as to control the means for managing the flow of the coolant, Temperature sensing yen controls the coolant flow management means according to at least two temperature setpoints Ti and T2, the temperature sensing means being able to control the coolant flow management means according to three set points Ti , T2 and T3 of temperature, the setpoint Ti being lower than the setpoint T2, the setpoint T2 being lower than the setpoint T3, - the coolant flow management means comprises at least five openings, the direction of flow of the coolant defining the nature of the openings so as to be either an outlet or an inlet.

  Other features and advantages will appear on reading the following description with reference to the figures in which: - Figure 1 is a simplified representation of a cooling circuit of an internal combustion engine, according to the invention FIG. 2 represents a longitudinal sectional view of a cylinder head of an internal combustion engine disposed in the cooling circuit of FIG. 1; FIG. 3 represents a sectional view along the axis AA of the cylinder head; of Figure 2.

  Internal combustion engines, in particular arranged on motor vehicles, traditionally cooperate with a cooling circuit, preferably hydraulic. The main functions performed by such a circuit are the recovery and transfer of thermal energy. It is thus traditionally disposed of a device for recovering thermal energy from the operation of a combustion engine to provide the thermal energy useful for heating a passenger compartment of a motor vehicle.

  Preferably, the fluid flowing in the cooling circuit is a coolant, such as water. Thus, the circulation of the coolant in the mechanical organs, such as the passages contained in the engine, or in heat exchangers, such as radiators or fan heaters, generates heat exchanges.

  These exchanges are necessary and are generally used for the cooling of the mechanical members. One of the mechanical parts of a vehicle is the engine, which is substantially composed of a cylinder head and a cylinder block.

  The cooling circuit of Figure 1 is a non-limiting example, given by way of example to illustrate the invention.

  The circuit of Figure 1 schematically shows the elements of an internal combustion engine, said elements being a cylinder head 1 and a cylinder block 6 preferably intended to be cooled by a coolant.

  In order to allow the circulation of the coolant, the circuit of FIG. 1 comprises means 15 for driving the coolant, means 10, 11 and 12 for managing the flow of the fluid, means 13 and 14 for heat exchange as well as that ducts 17 linking together each of the various means 10, 11, 12, 13, 14 and 15 and the elements 1 and 6 of the motor mentioned above.

  With such a circuit, the coolant is thus able to flow through the cylinder head 10 1 and the cylinder block 6 of the engine, but also through the heat exchange means 13 and 14 or through the branches 16 and 18.

  The flow of the coolant is managed by the means 10, 11 and 12 which provide a multiplicity of possible flows.

  The means 10, 11 and 12 for managing the flow of the coolant are preferably thermostats of the single or double-acting type with or without a discharge valve, solenoid valves, piloted thermostats or actuators with a plurality of inlets and outlets by examples. In the embodiments described later for example, the means 10, 11, 12 are actuators having a plurality of openings so as to allow communication between at least two openings. Thus, the flow management means 10 and 12 comprise six openings respectively 10a, 10b, 10c, 10d, 10e, 10f and 12a, 12b, 12c, 12e, 12f. The means 11 for managing the flow preferably comprises five openings, substantially the openings 11a, 11b, 11c, 11d and 11e.

  Depending on the coolant flow in the cooling circuit, the nature of an opening may be either an inlet or an outlet.

  The functions provided by each of the means 10, 11 and 12 of management can be performed by a solenoid valve and a thermostat or by any other association.

  According to the invention, the cooling circuit of an internal combustion engine advantageously comprises at least two passages intended for the circulation of the coolant in the cylinder head 1, and at least one passage intended for the circulation of the coolant in the cylinder block 6.

  The yoke 1 of the invention is more fully detailed below, with reference to FIGS. 2 and 3.

  Preferably, each of the two passages 2 and 3 crosses the cylinder head 1 from one side to the other so as to respectively comprise a separate inlet 2a or 3a, and a separate outlet 2b or 3b.

  As shown, the yoke 1 comprises a base 4, generally known as tablature. This base 4 cooperates with the cylinder block 6 indirectly. Indeed, a cylinder head gasket (not shown) is preferably disposed between the cylinder head 1 and the cylinder block.

  According to the invention, the cooling circuit provides that the passages 2 and 3 of the cylinder head 1 do not communicate with one of the cooling passages disposed in the cylinder block. Thus, each of the cooling passages of the engine allows an independent circulation of the coolant within it.

  In the embodiment of the cylinder head 1 of Figures 2 and 3, the cooling passages 2 and 3 of the cylinder head are parallel to each other.

  The first passage 2 is thus preferably located close to the exhaust ducts 5 of the cylinder head, while the second passage 3 is as close as possible to the base 4 of the cylinder head 1, hence to the tablature.

  The exhaust ducts 5 allow a flow of gases from the combustion chambers to an exhaust manifold and a pollution control system (not shown).

  The recovery of the thermal energy of the exhaust gas is necessary to make reliable the pollution control device traditionally arranged on an exhaust line (not shown) at the output of the engine.

  Advantageously, the temperature of the exhaust gas is regulated by the means 10, 11 and 12 for managing the coolant flow through the first passage 2 of the cylinder head 1, so as to optimize the operation of the decontamination while preserving it from any deterioration mainly due to a gas temperature too high.

  The second passage 3 is advantageously located as close as possible to the base 4 of the yoke 1, that is to say the tablature, so as to recover a thermal energy stored by the base 4. It is in fact known the rapid thermal rise of this part. of the cylinder head especially after the engine has been put into operation. The recovery of this thermal energy is thus performed by means of the circulation of the coolant through the second passage 3 disposed close to the tablature.

  According to the invention, the cooling circuit of FIG. 1 makes it possible to orient completely independently the coolant through at least one cooling passage of the engine, whether it be the first, the second or the third cooling passage.

  It is also conceivable to direct the coolant through at least two passages, one of which can advantageously be disposed after the other in the direction of the flow of the coolant, so that this successive circulation of the coolant through at least two passages can be described as series circulation.

  It is also conceivable to orient the fluid through at least two cooling passages, each of the passages then being arranged in parallel with each other.

  The means 10, 11 and 12 of the coolant flow even allow an inverted type of circulation through at least two passages, such as the first and second passages 2 and 3 of the cylinder head 1. In fact, a connection of series type of the two passages 2 and 3 allows a circulation of the coolant from the inlet 2a to the outlet 2b of the first passage 2, and a circulation of the outlet 3b to the arrival 3a of the second passage, so as to create a flow inverted coolant between these two first and second passages 2et3.

  Such a cooling circuit is advantageous in that it comprises flow management means capable of controlling different circulations of the coolant.

  The circuit of the invention will now be described in two embodiments, each thus detailing commands affecting the means 10, 11 and 12 for managing the coolant flow.

  Thus, in a first embodiment of the cooling circuit, a temperature sensing means (not shown) is preferably disposed at the output of the engine, for example at the means 11 for managing the flow of the coolant. Temperature sensing means controls the means 10, 11 and 12 of the coolant flow along two setpoints Ti and T2 temperature, so as to allow: - either a circulation of the coolant only through the second passage 3 of the engine, so as to recover the thermal energy dissipated at the tablature, the coolant then circulating simultaneously through the heater 14 and the bypass 16 as the temperature at the output of the pump 15 does not. does not reach a first temperature set point Ti. Such a circulation of the coolant is possible by the communications between the inlet 10a and the outlet 10c, between the inlet 11b and the outlet 11d and between the inlet 12a and the outlets 12c and 12d of the means 10, 11 and 12 management of coolant flow.

  or a circulation of the coolant only through the second passage 3 of the engine, so as to recover the thermal energy dissipated at the tablature 4, the coolant then circulating simultaneously through the heater 14 and the radiator 13 as the temperature at the outlet of the pump 15 is between the first setpoint T1 and a second setpoint T2 temperature. Such a circulation of the coolant is made possible by the communications between the input 10a and the output 10c, between the input 11b and the output 11d and between the input 12a and the outputs 12b and 12d means 10,11 and 12 of coolant flow management.

  or a simultaneous circulation of the coolant in the first and second passages 2 and 3, the first passage 2 being in series with the third passage so that the first and third passages are in parallel with the second passage 3, the coolant circulating thereafter simultaneously through the heater 14 and the radiator 13 as the temperature at the output of the pump 15 is greater than the second setpoint T2 temperature. Such a circulation of the coolant is made possible by the communications between the input 10a and the outputs 10b and 10c, between the input 10d and the output 10e, between the input 11b and the output 11d, between the input 11 a and the outlet 11c, and between the inputs 12a and 12e and the outlets 12b and 12d means 10, 11 and 12 for managing the coolant flow.

  In a variant of the first embodiment presented above, the temperature reading means controls the means 10, 11 and 12 of the coolant flow according to three setpoints T1, T2 and T3 of temperature, so as to allow : - either a circulation of the coolant only through the second passage 3 of the engine, so as to recover the thermal energy dissipated at tablature 4, the coolant then circulating simultaneously through the heater 14 and the derivation 16 as the temperature measured at the output of the pump 15 has not reached a first set point T1 of temperature. The previously described circulation is obtained by the communication between the inlet 10a and the outlet 10c of the flow management means 10, by the communication between the inlet 11b and the outlet 11d of the flow management means 11. and by the communication between the inlet 12a and the outlets 12c and 12d of the means 12 for managing the coolant flow.

  or a circulation of the coolant through a first loop containing the first passage 2, the second passage 3 and the means 15 for driving the coolant then positioned in series, and a second loop comprising the second passage 3, the heater 14 and the drive means 15 as the temperature measured at the output of the pump 15 is between the two temperature setpoints T1 and T2. Such a circulation requires the communications between the input 10a and the output 10c and between the input Ob and the output 10f, the communication between the input 11b and the outputs 11a and 11d, and the communication between the input 12a and the output 12d respectively 10, 11 and 12 means for managing the coolant flow.

  or a circulation of the coolant through a first loop containing the first passage 2, the second passage 3, the radiator 13 for cooling and the means for driving the coolant, and a second loop comprising the second passage 3, The heater 14 and the drive means 15 as long as the temperature measured at the output of the drive means 15 is between the two temperature sets T2 and T3. In this arrangement of the different elements, each is preferably positioned in series with another. Such a circulation is the result of the communications between the input 10a and the output terminal Oc, between the input 10b and the output 10e, between the input 11b and the outputs 11a and 11d, between the input 12e and the 12b outlet and between the inlet 12a and the outlet 12d means 10, 11 and 12 of the management of the coolant flow.

  or a simultaneous circulation of the coolant through a first loop containing the first passage 2, the second passage 3, the cooling passage of the cylinder block 6, the cooling radiator 13 of the coolant and the drive means 15. coolant, and a second loop comprising the second passage 3, the heater 14 and the drive means 15 as the temperature measured at the output of the drive means 15 is greater than the set T3. In this arrangement of the various elements present in the two loops previously mentioned, each is preferably positioned in series with another. The circulation of the coolant mentioned above is obtained by the communications between the input 10a and the output 10c, between the input 10b and the output 10d, between the input 1 1b and the outputs 1 1a and 1 1 d , between the inlet 11c and the outlet 11e, between the inlet 12a and the outlet 12d and between the inlet 12f and the outletelb of means 10, 11 and 12 for managing the flow of the coolant.

  In the two embodiments described above, the setpoint T1 is lower than the setpoint T2, just as the setpoint T2 is lower than the setpoint T3.

  With the cooling circuit of the invention, it is thus possible to manage the circulation of the coolant to increase heat exchange while taking into account various constraints, such as the operating conditions of a pollution control device, the needs in thermal energy for heating a cabin of a vehicle while optimizing the temperature rise of an internal combustion engine.

  Thus, the cooling circuit of the invention proposes a solution to the problem raised by the applicant. Indeed, such a circuit makes it possible during a phase of temperature rise of the engine to heat the cabin of the vehicle without decreasing the temperature of the exhaust gas, so as to make the operation of the pollution control device disposed in line more optimal. exhaust system of a motor vehicle for example.

2860833 11

Claims (17)

  Cooling circuit for an internal combustion engine having at least one cylinder head (1), a cylinder block (6), the circuit comprising heat exchange means (13, 14), driving means (15) a coolant and at least one means (10, 11, 12) for managing the flow of the coolant through the cylinder head (1), the cylinder block (6) or the heat exchange means (13, 14). ), characterized in that it comprises at least three independent passages dedicated to the cooling of the engine, the first and second passages (2, 3) being arranged in the cylinder head (1), the third passage being arranged in the cylinder block (6). ), the passages being distinct and comprising at least one inlet (2a, 3a, 6a) and an outlet (2b, 3b, 6b) so as to allow independent circulation of the heat transfer fluid through each of the passages of the cylinder head and of the cylinder block.   2. Circuit according to claim 1, characterized in that the management means (10, 11, 12) of the coolant flow act independently on each of the first, second and third cooling passages of the engine.   3. Circuit according to any one of claim 1 or 2, characterized in that the first and second cooling passages (2, 3) are arranged parallel to each other in the cylinder head (1).   4. Circuit according to any one of claims 1 to 3, characterized in that the first passage (2) is a cooling fluid core disposed close to the exhaust ducts (5) of the cylinder head (1) of the engine for recover the thermal energy from the gases leaving the combustion chamber.   5. Circuit according to any one of claims 1 to 4, characterized in that the second passage (3) is a cooling fluid core disposed near the base (4) of the engine cylinder head to recover thermal energy produced by combustion and dissipated by thermal conduction at the base (4).   6. Circuit according to any one of claims 1 to 5, characterized in that the management means (10, 11) of the fluid flow are connected to the arrivals (2a, 3a, 6a) and the outputs (2b, 3b, 6b) thereby allowing the coolant to flow in at least one of the passages of the cylinder head (1) and / or the cylinder block (6) in series or in parallel.   7. Circuit according to any one of claims 1 to 6, characterized in that the fluid flow is effected solely by the second passage (3) of the cylinder head (1) so as to recover thermal energy at the the base (4) of the cylinder head (1) for heating a passenger compartment of a vehicle, and to allow a rapid rise in temperature of the cylinder housing (6) and a pollution control system connected to the ducts (5) of exhaust.   8. Circuit according to any one of claims 1 to 7, characterized in that the flow direction of the cooling fluid is opposite in at least two of the cooling passages of the engine.   9. Circuit according to any one of claims 1 to 7, characterized in that the direction of flow of the cooling fluid is opposite in the first and second passages (2, 3) of the cylinder head (1), the passages being then arranged in series by the means (10, 11, 12) for managing the flow of the coolant, the outlet (2b) of the first passage (2) being thus connected to the outlet (3b) of the second passage (3) .   10. Circuit according to any one of claims 1 to 8, characterized in that the means (10, 11, 12) for managing the flow of heat transfer fluid allows a flow of fluid through at least one heat exchanger (13, 14) and / or a branch (16, 18) of derivation.   11. Circuit according to claim 9, characterized in that it comprises a means for measuring the temperature of the coolant preferably disposed at the outlet of the second passage (3) for cooling the cylinder head (1), so as to drive at least means (10, 11, 12) for managing the coolant flow.   12. Circuit according to claim 10, characterized in that the temperature sensing means controls the means (10, 11, 12) for managing the flow of the coolant according to at least two setpoints Ti and T2 temperature.   13. Circuit according to claim 10, characterized in that the temperature sensing means controls the means (10, 11, 12) for managing the coolant flow along three temperature instructions Ti, T2 and T3.   14. Circuit according to claim 12, characterized in that the setpoint T1 is lower than the setpoint T2, and the setpoint T2 is lower than the setpoint T3.   15. Circuit according to any one of claims 12 to 14, characterized in that the means (10, 11, 12) for managing the coolant flow comprises at least two openings.   16. Circuit according to any one of claims 12 to 15, characterized in that it comprises at least three means (10, 11, 12) for managing the coolant flow.   17. Circuit according to any one of claims 15 and 16, characterized in that the direction of flow of the coolant defines the nature of the openings of the means (10, 11, 12) coolant flow management, so to be either an exit or an entry.