FR2791088A1 - COOLING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

A cooling installation for an internal combustion engine of a motor vehicle, comprises a primary coolant circuit (2) for cooling the internal combustion engine (5), and at least one coolant circuit secondary (3) for cooling a fluid or a unit of the motor vehicle, a common compensation tank (9) being provided for the two circuits, and serving to compensate for variations in the volume of coolant in the circuits. In order to improve the operational safety of the internal combustion engine cooled by this installation, the primary coolant circuit is connected by a primary connector (23), and the secondary coolant circuit by a secondary connector (25), separate, to the compensation tank, the secondary connection opening into the compensation tank at a higher level than the primary connection.

Description

The invention relates to a cooling installation for a motor with

  internal combustion of a motor vehicle, comprising a primary coolant circuit for cooling the

  internal combustion engine, and at least one coolant circuit

  secondary for cooling a fluid or a unit of the motor vehicle, a common compensation tank being provided for the coolant circuits, and serving to compensate for variations in the volume of coolant in the circuits of coolant, and in particular to purge the circuits of coolant

cooling.

  Document DE-AS 1 206 211 shows a cooling installation

  of the type cited in the introduction. The known cooling installation comprises a primary coolant circuit which is used to cool the internal combustion engine of the motor vehicle, here a hydraulic diesel locomotive. The cooling installation further comprises a secondary coolant circuit, which is used for cooling a fluid or a unit of the motor vehicle, here for cooling the intake air of the internal combustion engine. For the two coolant circuits, a common compensation tank is provided, which serves to compensate for variations in the volume of the coolant in the coolant circuits, and

  preferably also bleeding the coolant circuits.

  The present invention aims to improve a cooling installation

  of the type mentioned in the introduction, so as to increase the operating safety of the internal combustion engine cooled by the

  primary coolant circuit of the cooling system

  sement. This is achieved in accordance with the invention, thanks to a cooling installation characterized in that the primary coolant circuit is connected by a primary connection to the compensation tank and opens into the compensation tank at a first level of agent

  and that the secondary coolant circuit

  daire is connected by a separate secondary connection to the compensation tank and opens into the compensation tank to a second

  coolant level, the second level of coolant

  ment being located higher than the first level of coolant.

  The invention is based on the general idea of connecting the primary coolant circuit and the secondary coolant circuit separately to the compensation tank, the connection points being chosen in such a way that in the case of '' a lowering coolant level in the compensation tank, that is all

  first the coolant flow from the compensating tank

  sation in the secondary coolant circuit which ends, while a coolant flow in the primary coolant circuit is still possible. In this way, the correct operation of the primary coolant circuit can

  be kept longer in case of coolant loss

  is lying. In particular, a leak in the secondary coolant circuit cannot cause a malfunction of the primary coolant circuit. This concept is carried out in accordance with

  the invention, by the fact that the mouth of the coolant circuit

  secondary in the compensation tank is at a level higher hydrostatically than the mouth of the primary coolant circuit. Overall, it is thus possible to reduce the risk of damage to the internal combustion engine, due to overheating.

  According to a preferred embodiment of the cooling installation

  In accordance with the invention, the level of the mouth of the secondary coolant circuit (second level of coolant) is chosen so that it is located at least as high as a minimum level necessary to maintain proper cooling of the internal combustion engine through the primary coolant circuit. In this way, it is possible to guarantee that the internal combustion engine will be operated without risk of damage, even when the secondary coolant circuit, due to losses of coolant, already works only with reduced capacity or is

already completely out of order.

  If in accordance with a development of the cooling system

  In accordance with the invention, the second level of coolant is below a limit level which, for the detection of a coolant leak, is monitored by monitoring means, which generate a alarm signal when the coolant level reaches the limit level, it is possible to guarantee that the coolant deficit is detected at a time when the coolant circuits are still working properly, so that it is thus possible to avoid damage resulting from the loss of

cooling.

  According to another characteristic of the invention, the primary connector opens into the compensation tank at the lowest point on

the hydrostatic plane.

  According to a configuration of the invention, the coolant circuit

  secondary secondary can be used to cool the intake air.

  According to a preferred embodiment of the invention, the secondary connector

  daire is formed by a tubular tip, which projects inside the

  compensation tank by being from the bottom thereof.

  According to one embodiment of the invention, several secondary coolant circuits can be provided, the secondary connection or the secondary connections of which emerge in the compensation tank at the second level of coolant or up to the second coolant level to coolant levels staged from top to bottom in accordance with their importance

  for safe operation of the vehicle.

  Other important characteristics and advantages of the cooling installation according to the invention result from the appended drawing as well as

  of the associated description of the figure in this drawing.

  It is obvious that the characteristics mentioned above and which will be explained further below, are not only valid

  according to the combinations indicated, but also according to other combinations

  sounds or taken individually, without departing from the scope of the present invention.

  A preferred embodiment of the invention is shown in the

  drawing and will be explained in more detail in the description which follows.

  Figure 1 single shows a schematic representation of principle for an arrangement of the cooling installation according to the invention.

  The lines carrying coolant are shown

  felt by double lines in Figure 1, while lines

  carrying gas are represented by simple lines.

  In accordance with FIG. 1, the cooling installation 1 according to the invention comprises a cooling agent circuit

  primary 2 as well as a secondary coolant circuit 3.

  The primary coolant circuit 2 is used for cooling an internal combustion engine 5 and includes an air / coolant heat exchanger 4 supplied with air. The air supply to the air / coolant heat exchanger 4 is symbolized by an arrow 6. A coolant pump 7 conveys the coolant having been cooled, the air heat exchanger /agent of

  cooling 4 to the internal combustion engine 5. The coolant

  overheated comes out of the internal combustion engine 5 and is transferred to

  the air / coolant heat exchanger 4.

  The primary coolant circuit 2 communicates with a

  compensation tank 9, via a connecting pipe

  primary ment 8. In addition, a purge line 10 is provided which connects a suitable place in the coolant circuit

  primary 2 with the compensation tank 9.

  The secondary coolant circuit 3 is used for cooling

  intake air, which is supplied to the internal combustion engine for combustion. The cooled intake air is supplied here by means of a section, designated by the reference 11, of a supply air supply pipe. The coolant circuit

  secondary 3 contains an air / coolant heat exchanger

  ment 12 supplied with air. The air supply is here also symbolized by an arrow 6. A coolant pump 13 conveys the cooled coolant from the air / coolant heat exchanger 12 to a coolant heat exchanger / intake air 14. The heated coolant exits the coolant / intake air heat exchanger 14 and is recycled to

  the air / coolant heat exchanger 12.

  Coolant / intake air heat exchanger 14

  is supplied by an exhaust turbocharger 16 with intake air

  pressure which has been heated by compression in the exhaust turbocharger 16. A section of the intake air supply supplying the heated intake air from the exhaust turbocharger 16 to the coolant heat exchanger / intake air 14, is here designated by the reference 15. In the embodiment shown, the

  exhaust turbocharger 16 is driven by exhaust gases

  ment of the internal combustion engine 5, which is symbolized by an exhaust gas line 17. The exhaust gases expanded in the exhaust turbocharger 16 are sent, via

  from a line 18, to an exhaust gas depollution system.

  The air provided for combustion in the internal combustion engine 5 is taken from the environment by the exhaust turbocharger 16,

  via a suction line 19.

  The secondary coolant circuit 3 communicates, via a secondary connection line 20, with the compensation tank 9. For the secondary coolant circuit 3, a purge line 21 is also provided, which connects a suitable place in the coolant circuit

  secondary 3 with the compensation tank 9.

  The compensation tank 9 thus serves for the two circuits of coolant 2 and 3, to compensate for variations in the volume of coolant, which are, for example, to be taken into account for thermal expansion effects. In addition, the purge of the two agent circuits

  cooling 2 and 3 is also carried out by the compensation tank

  tion 9 common. In addition, the common compensation tank 9 allows simultaneous filling of the cooling agent for the two cooling agent circuits 2 and 3, via a manifold of

  filling 22 of the compensation tank 9.

  In accordance with the invention, a primary connector 23, through which the primary connection pipe 8 and connected to the compensation tank 9, opens at a first level of coolant 24 in the compensation tank 9. Conversely, a secondary connection, by which the secondary connection line 20 is connected to the compensation tank 9, opens at a second level of coolant 26, in the compensation tank 9. According to the invention, the second level of coolant 26 is higher on the hydrostatic plane, than the first level of coolant

cooling 24.

  While the first level of coolant 24 represents the minimum possible level of liquid in the compensation container 9, i.e. a completely empty compensation tank 9, the second level

  coolant 26 corresponds to a coolant level

  still providing sufficient coolant

  in the compensation tank 9, to operate correctly-

  the primary coolant circuit 2 for cooling

of the internal combustion engine 5.

  In the embodiment shown by way of example in the figure

  1, the primary connector 23 is connected to a bottom 32 of the compensation tank

  sation 9, so that the mouth of the primary connection 23 arrives

  substantially flush with the bottom 32, the first level of coolant

  ment 24 thus corresponding to the level of the bottom. Conversely, the secondary connector 25 is produced in the form of a tubular end piece, which passes through the bottom 32 and, coming from it, projects upwards, inside the compensation tank 9 , up to the second agent level

cooling 26.

  Above the second level of coolant 26, in the compensation container 9, is defined a limit level 27 which represents the minimum filling level for the coolant, for which it is still possible to guarantee operation correct of all the cooling agent circuits 2 and 3. The cooling installation 1 according to the invention preferably comprises monitoring means, for example a detector 28, making it possible to monitor the filling level, namely the coolant level in the compensation tank 9, with a view to generating, when the limit level 27 is reached, an appropriate alarm signal, which is supplied by a signal line 29,

  for example to a motor control not shown.

  Above the limit level 27, a level of coolant 30 is shown, which the coolant can take for normal and correct operation of the coolant circuits 2 and 3. Above this level of normal coolant 30, one

  defines in the compensation tank 9, a maximum level 31, which represents

  feels the maximum filling level for the coolant.

  When in the cooling installation 1 losses of coolant appear, in particular when the secondary coolant circuit 3 has a leak, the coolant which escapes is correspondingly replaced by coolant in the compensation tank 9, resulting in a gradual lowering of the level of coolant in the compensation tank 9. Thanks to the arrangement according to the invention of the mouths of the coolant circuits 2 and 3 in the compensation tank 9, at different coolant levels 24 and 26, a flow of coolant from the compensation tank 9 in the secondary coolant circuit 3 is interrupted or terminated as soon as the level of coolant in the compensation tank 9 reaches the second level of coolant 26. In the case where one is in the presence of a leak in the secondary coolant circuit 3, it is then no longer possible to guarantee a correct operating mode of the secondary coolant circuit 3, which however does not at first constitute a direct risk for the internal combustion engine 5. In the present case, the intake air can no longer be cooled, which however only causes a degradation of the efficiency of the internal combustion engine. However, the primary coolant circuit 2 remains fully capable of operating properly, even when the coolant level has reached the second coolant level 26,

  so that overheating of the internal combustion engine can be excluded 5.

  By decoupling the secondary coolant circuit 3 from the compensation tank 9, from the second level of coolant 26, the volume of coolant still remaining

  in the compensation tank 9, can be used exclusively to serve the primary coolant circuit 2, which ensures sufficient cooling of the internal combustion engine 5 for a relatively long time, thereby preserving the internal combustion engine 5 as long as possible from overheating.

Claims (7)

R E V E N D I C A T I ON S   1. Cooling system for an internal combustion engine   (5) of a motor vehicle, comprising a coolant circuit   primary ment (2) for cooling the internal combustion engine (5), and at least one secondary coolant circuit (3) for cooling a fluid or a unit of the motor vehicle, a reservoir for common compensation (9) being provided for the coolant circuits (2 and 3), and serving to compensate for variations in   volume of coolant in coolant circuits   ment (2 and 3), and in particular to purge the coolant circuits   ment (2 and 3), characterized in that the primary coolant circuit (2) is connected by a primary connection (23) to the compensation tank (9) and opens into the compensation tank (9) at a first level of coolant (24), and in that the secondary coolant circuit (3) is connected by a separate secondary connection (25) to the compensation tank (9) and opens into the tank compensation (9) to a second level of coolant (26), the second level of coolant (26) being   located higher than the first level of coolant (24).   2. Cooling installation according to claim 1, characterized in that the second level of cooling agent (26) is located at   less so high than a minimum level necessary to keep it cool   of the internal combustion engine.   3. Cooling installation according to claims 1 or 2,   characterized in that the second level of coolant (26) is located below a limit level (27) which, for the detection of a coolant leak, is monitored by monitoring means ( 28), these monitoring means (28) generating an alarm signal when   the coolant level reaches the limit level (27).   4. Cooling installation according to one of claims 1 to 3,   characterized in that the primary connection (23) opens into the tank   compensation (29) at the lowest point on the hydrostatic plane.   5. Cooling installation according to one of claims 1 to 4,   characterized in that the secondary coolant circuit (3)   used to cool the intake air.   6. Cooling installation according to one of claims 1 to 5,   characterized in that the secondary connection (25) is formed by a tubular end piece which projects inside the compensation tank (9) in being from the bottom of it.   7. Cooling installation according to one of claims 1 to 6,   characterized in that several coolant circuits are provided   secondary ment (3) whose secondary connection (25) or secondary connections (25) open into the compensation tank (9) at the second level of coolant (26), or up to the second level of coolant cooling to coolant levels staged from top to bottom in accordance with their importance to the safety of the vehicle operation.