WO2014167199A1

WO2014167199A1 - Cooling circuit for an internal combustion engine

Info

Publication number: WO2014167199A1
Application number: PCT/FR2014/050640
Authority: WO
Inventors: Anthony Frainet; Jeremy Gambazza; Jacques Dusi; Kiwan NOSSIN
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2013-04-12
Filing date: 2014-03-19
Publication date: 2014-10-16
Also published as: FR3004490B1; FR3004490A1

Abstract

The invention relates to a cooling circuit (2) of a power train comprising, in particular, an internal combustion engine (1) provided in a motor vehicle. The power train (1) comprises an internal circuit (3) for the cooling fluid to flow into the internal combustion engine (1). The internal circuit (3) is provided with a housing (4) at the outlet of the internal circuit (3). The cooling circuit (2) comprises a first conduit (6) linking the housing (4) to a unit heater (7) and a first pipe (14) linking a radiator (13) to the housing (4). The first pipe (14) is provided with two tappings (20, 21), including an upstream tapping (20) provided with an upstream tapping channel (22) and a downstream tapping (21) provided with a downstream tapping channel (23). A heat exchanger (25) is interposed between the upstream tapping channel (22) and the downstream tapping channel (23). A first bypass channel (27) links the first conduit (6) to the upstream tapping channel (22).

Description

ENGINE COOLING CIRCUIT

INTERNAL COMBUSTION

The invention relates to a cooling circuit and more particularly to a cooling circuit of a powertrain, in particular an internal combustion engine preferably associated with a gearbox, and one or more other bodies composed for example of one or more heat exchangers, for example water / oil in the case of an automatic gearbox, equipping a motor vehicle. The power train, in particular the internal combustion engine, comprises an internal circuit for circulating the cooling fluid inside the internal combustion engine, the internal circuit being provided with a casing at the outlet of the internal circuit, the cooling circuit comprising a first conduit connecting the housing to a heater and a first pipe connecting a radiator to the housing, the first pipe being provided with two connections, including an upstream branching provided with an upstream branch pipe and a downstream branch provided with a downstream tapping channel, a heat exchanger (which may be an external exchanger of the type of a water / oil exchanger of a gearbox) being interposed between the upstream tapping channel and the downstream tapping channel.

The document FR 2,838,477 describes a cooling circuit of an internal combustion engine fitted to a motor vehicle. The cooling circuit comprises a radiator which constitutes a heat exchanger for cooling the cooling fluid at the outlet of the internal combustion engine. The internal combustion engine houses an internal cooling fluid circulation circuit which is connected to a first pipe for supplying the cooling fluid to the radiator. The radiator is also connected to the internal coolant circulation circuit via a second conduit which returns the cooled coolant to the internal combustion engine. The cooling circuit also comprises a heater circuit connected to the internal circulating circuit by a first cooling fluid return duct to the internal combustion engine and a second supply duct of the air heater circuit from fluid from the internal combustion engine.

The second supply duct of the circuit heater and the first duct bringing the cooling fluid leaving the internal combustion engine in the radiator are connected to a housing containing a thermostat. At low temperature cooling fluid, for example during the cold start of the internal combustion engine, the thermostat closes the first pipe supplying the radiator with cooling fluid. The cooling fluid then circulates only in the air heater circuit. When the temperature rises the thermostat opens the first pipe supplying the radiator with cooling fluid so as to effectively cool the latter. When the temperature of the coolant is for example of the order of 90 ° C the thermostat completely releases the opening of the first pipe supplying the radiator.

The cooling circuit also includes a heat exchanger for cooling an automatic gearbox. The heat exchanger is connected to the second pipe. Two taps are made on the second pipe to connect the heat exchanger in parallel through an upstream channel and a downstream channel. The downstream channel is provided with a degassing conduit which connects the downstream pipe to the housing and which comprises an expansion jar.

When the temperature of the cooling fluid is low, the cooling fluid flow inside the radiator is low, or zero, since the circulation of the cooling fluid is mainly carried out inside the air heater circuit. Therefore, to force the fluid to circulate inside the heat exchanger a section restriction is made in the second radiator outlet pipe between the two connections of the heat exchanger. The section reduction of the second pipe causes a counterpressure upstream restriction which tends to promote the circulation of the cooling fluid inside the heat exchanger. In addition, the second restriction, air heater side, will allow to circulate liquid in the bypass to supply the gearbox. The disadvantage of not having this bypass thermostat closed is that there is no flow, so no heat exchange in the exchanger.

Such a restriction generates pressure losses inside the cooling circuit which penalizes all the heat exchange carried out inside the cooling circuit, both by the radiator and the heater. In other words, the presence of such a restriction decreases the flow rates in the various lines that comprise the cooling circuit, which it is preferable to avoid. It follows that such a restriction disturbs and minimizes a cooling function of the internal combustion engine via the radiator and a heating function of a flow air delivered inside the passenger compartment of the motor vehicle, such a function being performed via the heater.

An object of the present invention is to provide a cooling circuit of an internal combustion engine fitted to a motor vehicle that is able to effectively cool another element fitted to the motor vehicle, such as an automatic gearbox or analogous, under various operating conditions of the internal combustion engine, such as a cold start of the internal combustion engine in particular. Another object of the present invention is to provide a cooling circuit comprising minimized pressure losses while allowing optimized heat exchange through at least one radiator, a heater and a heat exchanger that the cooling circuit comprises .

A cooling circuit of the present invention is a cooling circuit of a powertrain, including an internal combustion engine, and equipping a motor vehicle. The powertrain comprises an internal circuit for circulating the cooling fluid inside the internal combustion engine. The internal circuit is provided with a housing at the output of the internal circuit. The cooling circuit includes a first conduit connecting the housing to a heater and a first conduit connecting a heater to the housing. The first pipe is provided with two connections, one of which is an upstream branch with an upstream tapping channel and a downstream branch with a downstream tapping channel. A heat exchanger is interposed between the upstream tapping channel and the downstream tapping channel.

It understands by powertrain at least one internal combustion engine, preferably associated with a gearbox (which can be automatic, manual or any other type).

According to the present invention, a first bypass channel connects the first pipe to the upstream stitching channel.

[001 1] The cooling circuit advantageously comprises a second bypass channel which connects the first bypass channel and a degassing box.

The housing is advantageously provided with a second conduit connecting the housing to a coolant collector equipping an input of the internal circuit.

The housing is advantageously provided with a third pipe connecting the housing to the radiator. The radiator is advantageously provided with a second pipe which connects the radiator to the degassing box.

The degassing box is advantageously provided with a third pipe which connects the degassing box to the collector.

The heater is advantageously equipped with a fourth pipe that connects the heater either indifferently to the second pipe or manifold.

[0017] A motor vehicle of the present invention is equipped with an internal combustion engine provided with such a cooling circuit.

The heater is preferably housed inside a heating system of the motor vehicle, to be traversed by an internal air flow.

The radiator is preferably housed inside a front facade of the motor vehicle, to be traversed by an external air flow.

Other features and advantages of the present invention will appear on reading the description which will be made of embodiments, in connection with the figures of the attached sheet, in which:

FIG. 1 is a schematic view of a cooling circuit of the present invention,

• Figure 2 is a schematic view of an insert that includes the cooling circuit illustrated in the previous figure.

In Figure 1, an internal combustion engine 1 equips a motor vehicle to allow movement of the latter. The internal combustion engine 1 is provided with a cooling circuit 2 of the internal combustion engine 1 inside which circulates a cooling fluid, such as a mixture of water and glycol, for example. The cooling circuit 2 comprises an internal circuit 3 for circulating the cooling fluid inside the internal combustion engine 1 to charge the cooling fluid in calories inside the internal combustion engine 1. The cooling circuit is intended to take the calories generated by the internal combustion engine 1 and to evacuate them to maintain the internal combustion engine at an acceptable operating temperature.

The internal combustion engine 1 is equipped at the output of the internal circuit 3 of a casing 4 for the output of the cooling fluid. The housing 4 is intended to distribute the fluid cooling inside various lines 6, 9, 12 that includes the cooling circuit 2.

The housing 4 comprises a first outlet 5 of cooling fluid which is provided with a first pipe 6 connecting the housing 4 to a heater 7. In other words, the first pipe 6 is provided to allow circulation of the cooling fluid. from the housing 4 to the heater 7. The heater 7 is traversed by an internal air flow which is intended to be delivered inside a passenger compartment of the motor vehicle to heat an air present inside the vehicle. the cockpit. The heater 7 is preferably housed inside a heating installation of the motor vehicle.

The housing 4 comprises a second cooling fluid outlet 8 which is provided with a second pipe 9 connecting the housing 4 to a collector 10 of cooling fluid equipping an inlet of the internal circuit 3. In other words, the second pipe 9 is provided to allow circulation of the cooling fluid from the housing 4 to the collector 10. The collector 10 is intended to receive the cooling fluid at the inlet of the internal circuit 3.

The housing 4 comprises a third outlet 1 1 of cooling fluid which is provided with a third pipe 12 connecting the housing 4 to a radiator 13. In other words, the third pipe 12 is provided to allow a circulation of the fluid of cooling from the housing 4 to the radiator 13. The radiator 13 is traversed by an external air flow to cool the cooling fluid inside the radiator 13. The radiator 13 is preferably housed inside a facade front of the motor vehicle to facilitate a heat exchange between the external air flow and the cooling fluid inside the radiator 13.

The radiator 13 is provided with a first pipe 14 which connects the radiator 13 to an inlet 15 which comprises the housing 4. In other words, the cooling fluid cooled inside the radiator 13 is conveyed from the radiator 13 to the inlet 15 of the housing 4 via the first pipe 14.

The radiator 13 is provided with a second pipe 16 which connects the radiator 13 to a degassing box 17 of the coolant. The degassing box 17 allows degassing of the cooling fluid when the latter reaches a temperature at which the cooling fluid contains air bubbles detrimental to heat exchange. The degassing box 17 is provided with a third pipe 18 which connects the degassing box 17 to the collector 10 for supplying the internal circuit 3 with degassed cooling fluid.

The heater 7 is equipped with a fourth pipe 19 which connects the heater 7 to the second pipe 9 or manifold 10 to bring the coolant from the heater 7 to the manifold 10.

The first pipe 14 is provided with two connections 20,21 including an upstream branching 20 provided with an upstream stitching channel 22 and a downstream stitching 21 provided with a downstream stitching channel 23. The upstream stitching 20 is formed upstream of a downstream tapping 21 in a direction of circulation 24 of the cooling fluid from the radiator 13 to the inlet 15. A heat exchanger 25 is interposed between the upstream tapping channel 22 and the downstream tapping channel 23 In other words, the coolant flows from the upstream tapping 20 inside the upstream tapping channel 22, then the heat exchanger 25, then inside the downstream tapping channel 23 before joining the first pipe. The heat exchanger 25 equips an element 33 of the motor vehicle, such as preferably an automatic gearbox, so that the cooling fluid present inside the heat exchanger 25 calge for cooling said element 33. These arrangements are such that the cooling fluid circulating inside the heat exchanger 25 comes from the radiator 13 inside which the cooling fluid has been previously cooled, which allows to effectively cool said element 33.

The housing 4 houses a thermostat 26 which is adapted to allow a flow of the cooling fluid through the second outlet 8 and / or the third outlet 1 1 depending on a coolant temperature. During a start of the internal combustion engine 1 to cold, the thermostat 26 closes the third output 1 1 and leaves open the second output 8. When the temperature of the coolant exceeds a threshold temperature, the thermostat 26 closes the second output 8 and leaves at least partially open, or even fully open, the third outlet 1 1 to allow cooling of the cooling fluid as it passes through the radiator 13.

According to the present invention, the cooling circuit 2 comprises a first bypass channel 27 which connects the first duct 6 to the upstream quench channel 22. In other words, the first bypass channel 27 extends between a point of contact. inlet 28 provided on the first pipe 6 and an outlet point 29 formed on the upstream tapping channel 22. These arrangements allow the cooling fluid passing the first outlet 5 at the outlet of the casing 4 to flow preferentially inside the first bypass channel 27, the heater 7 generating pressure drops against the circulation of the cooling fluid therethrough while the first bypass channel 27 is free of heat exchanger or similar component forming an obstacle to the flow of the cooling fluid. In other words, the bypass channel 27 is more permeable to the flow of the cooling fluid than the heater 7, so that at the point of entry 28 the cooling fluid easily borrows the first bypass channel 27. Provisions allow a permanent cooling of said element 33, and therefore including the automatic gearbox of the motor vehicle, regardless of the position of the thermostat 26, and whatever the temperature of the cooling fluid.

Such cooling is also obtained without a nozzle and / or restriction affecting the cooling circuit 2, which avoids additional pressure drops on the cooling circuit 2 in addition to those generated by the heat exchangers that includes the cooling circuit 2, such as the heater 7, the radiator 13 and the heat exchanger 25, or other components of the cooling circuit 2, such as the internal circuit 3, the housing 4, the collector 10 and the box 17. The result of these provisions is a natural flow of the cooling fluid, that is to say a non-forced flow, from the housing 4 to the heat exchanger 25.

It follows from all these provisions a maximization of cooling fluid flows inside the pipes 6,9,12, 14,16,18 pipes and stitching channels 22,23. This results in an optimization of the heat exchange inside the heater 7, the radiator 13 and the heat exchanger 25 and consecutively an optimization of the thermal performance of the cooling circuit 2 of the internal combustion engine 1. This finally results in a perpetuation of the internal combustion engine 1 and said element 33, such as the automatic gearbox of the motor vehicle.

According to an alternative embodiment of the present invention, the entry point 28 of the first bypass channel 27 is placed on the first pipe 6 directly at the outlet of the housing 4 to facilitate a flow of the cooling fluid to the upstream channel stitching 22 and consecutively to the heat exchanger 25.

A second bypass channel 28 connects the first bypass channel 27 and the degassing box 17 to allow degassing of at least one yoke equipping the internal combustion engine 1. In other words, the second branch channel 28 extends between an upstream point 30 that includes the first bypass channel 27 and a downstream point 31 that comprises the degassing box 17. These provisions allow degassing of the cylinder head without affecting the housing 4.

Referring also to Figure 2, such a cooling circuit 2 preferably comprises an insert 31 which constitutes the first conduit 6, the first bypass channel 27 and the second bypass channel 28, such an insert 31 comprising a pipe forming an internal space 32 of the insert 31 and having two first openings 31a, 31b in relation to the first pipe 6, a second opening 31c in relation to the first bypass channel 27 and a third opening 31 d in relation to the second bypass channel 28. Such an insert 31 advantageously forms a four-way insert for the flow of the cooling fluid.

It will be noted at this stage of the description that, in FIG. 1, the respective lengths of the pipes 6, 9, 12, the pipes 14, 16, 18 and the stitching channels 22, 23 are schematic and not representative of a real length of these components of the cooling circuit 2.

Claims

1. Cooling circuit (2) of a powertrain, comprising in particular an internal combustion engine (1), equipping a motor vehicle, the powertrain (1) having an internal circuit (3) for circulating the cooling fluid to inside the internal combustion engine (1), the internal circuit (3) being provided with a housing (4) at the outlet of the internal circuit (3), the cooling circuit

(2) comprising a first pipe (6) connecting the housing (4) to a heater (7) and a first pipe (14) connecting a radiator (13) to the housing (4), the first pipe (14) being provided with two taps (20,21), including an upstream tap (20) provided with an upstream taping channel (22) and a downstream tap (21) provided with a downstream taping channel (23), a heat exchanger (25). ) being interposed between the upstream tapping channel (22) and the downstream tapping channel (23), characterized in that a first bypass channel (27) connects the first pipe (6) to the upstream tapping channel (22) .

2. Cooling circuit (2) according to the preceding claim, characterized in that the cooling circuit (2) comprises a second bypass channel (28) which connects the first bypass channel (27) and a degassing box (17). ).

Cooling circuit (2) according to one of the preceding claims, characterized in that the housing (4) is provided with a second pipe (9) connecting the housing (4) to a fluid collector (10). cooling equipping an input of the internal circuit

(3).

Cooling circuit (2) according to one of the preceding claims, characterized in that the housing (4) is provided with a third pipe (12) connecting the housing (4) to the radiator (13).

Cooling circuit (2) according to one of Claims 2 to 4, characterized in that the radiator (13) is provided with a second pipe (16) which connects the radiator (13) to the degassing box ( 17).

Cooling circuit (2) according to claims 2 and 3, characterized in that the degassing box (17) is provided with a third pipe (18) which connects the degassing box (17) to the manifold (10). .

Cooling circuit (2) according to one of claims 3 to 6, characterized in that the heater (7) is equipped with a fourth pipe (19) which connects the heater (7) to the second duct (9) or at the collector (10).

8. Motor vehicle equipped with an internal combustion engine (1) provided with a cooling circuit according to one of the preceding claims.

9. Motor vehicle according to claim 8, characterized in that the heater (7) is housed inside a heating system of the motor vehicle, to be traversed by an internal air flow.

10. Motor vehicle according to one of claims 8 or 9, characterized in that the radiator (13) is housed inside a front facade of the motor vehicle, to be traversed by an external air flow.