FR2962074A1 - COOLING A BATTERY BOX FOR FEEDING A DRIVE MOTOR OF A MOTOR VEHICLE. - Google Patents

Abstract

Motor vehicle battery tray cooling system (2) comprising a first part (10) out of the battery tray (2) and a second part (20) inside the battery tray, characterized in that the first part (10) comprises: - a first truncated circuit (11) cooling a first cooling liquid and - first connection means (19) arranged on a traffic lane of the first circuit (11), and in that the second part (20) comprises: - second connecting means (29) cooperating with the first connecting means (19) removably to form a connection (30) adapted to close or open the first circuit (11) circulation, - an exchanger (22) in which the first cooling liquid circulates for cooling a second cooling fluid, - a second circuit (21) in which the second cooling fluid circulates for cooling at least one battery (8) of the battery tray.

Description

The present invention relates to a cooling system for battery tray of a motor vehicle. It also relates to the two main parts of this cooling system, on a battery tray, a motor vehicle and a battery charging device comprising at least one of these parts. Finally, the invention also relates to a method of mounting or dismounting a battery tray on a motor vehicle or a battery charging device.

Some motor vehicles, such as electric or hybrid vehicles, include one or more batteries for powering an electric drive motor. Such a battery heats up during use, both during the driving period of the motor vehicle and charging period. This heating may induce premature aging of a battery. Thus, the solutions of the state of the art use cooling solutions of the battery.

The document FR2876223 describes for example the cooling of several battery packs arranged in a compartment by a flow of air, taken by means of a blower. The disadvantage of this solution stems from the fact that the cooling obtained remains generally mediocre.

On the other hand, it is interesting to exchange a battery when its energy level is low against a new charged battery. This can be done in a station similar to a service station in which one can fill a gas tank of a motor vehicle. Such a solution, however, makes it more difficult to cool the battery because the chosen solution must remain compatible with the removable nature of the battery, and allow a large number of assembly / disassembly operations of the battery. The object of the invention is therefore to provide an improved solution for cooling a battery of a motor vehicle.

More specifically, the invention seeks to achieve the following objects:

A first object of the invention is to provide a battery cooling solution of a motor vehicle which involves a high-performance heat exchange, to obtain efficient cooling at lower cost.

A second object of the invention is to provide a battery cooling solution of a motor vehicle compatible with the removable nature of a battery.

To this end, the invention is based on a cooling system for a motor vehicle battery tray, comprising a first part out of the battery tray and a second part inside the battery tray, characterized in that the first part part comprises: - a first truncated circuit cooling a first cooling liquid and - first connection means arranged on a circulation path of the first circuit, and in that the second part comprises: - second connecting means cooperating with the first releasably connecting means for forming a connection adapted to close or open the first circulation circuit, an exchanger in which the first cooling liquid circulates for cooling a second cooling fluid, a second circuit in which the second circulation circulates. second coolant for cooling at least one battery of the battery tray. This first part of a battery tray cooling system may comprise a first truncated circuit cooling a first coolant and first connecting means arranged on a circulation path of the first circuit.

The first circuit may comprise a first exchanger to allow cooling of the first cooling liquid by ambient air and / or a second exchanger to allow cooling of the first cooling liquid using another type of cooling circuit. air conditioner.

The first part may comprise a valve for opening or closing the circulation of the first coolant in the first exchanger and / or in the second exchanger.

The first part may include an expansion vessel forming a reservoir for the first coolant.

The first part may comprise a valve on the path comprising the expansion vessel under this expansion vessel for opening or closing the circulation of the liquid in the expansion vessel.

The first part of a battery tray cooling system may include at least one pump for the circulation of the first coolant.

The first part may comprise a first pump on the track comprising the expansion tank under this expansion tank and a second pump near a connecting means forming the outlet of the first part for the first cooling liquid.

The invention also relates to a motor vehicle or battery charging device, characterized in that it comprises a first part of a cooling system for motor vehicle battery tray as described above.

The invention also relates to a battery tray for a motor vehicle comprising at least one battery, characterized in that it comprises second connecting means arranged on a traffic lane of a first circuit, an exchanger in which a first coolant of the first circuit for cooling a second cooling fluid, and a second cooling circuit in which the second cooling fluid circulates to cool the at least one battery.

The exchanger may be a vertical exchanger in which the first coolant flows from bottom to top.

The invention also relates to a cooling system for battery tray for a motor vehicle, characterized in that it comprises a first part as described above and a battery tray as described above.

The invention also relates to a motor vehicle, comprising a battery tray for powering its drive motor, characterized in that it comprises a cooling system of its battery tray as described above.

The invention also relates to a method of disassembling a battery tray of a motor vehicle or a battery charging device, characterized in that it comprises a step of disconnecting a connection between two means of connection arranged on a taxiway of a first circuit of a cooling system of the battery tray in which a first coolant circulates, for separating a first part out of the battery tray of a second part within the tank battery pack cooling system and in that it comprises a step of separating the battery tray.

The method of disassembling a battery tray may include a step of draining at least partially the first circuit of the cooling system of the battery tank of the first coolant. The coolant draining step may include suctioning a coolant pump into an expansion tank and closing a valve to hold it in the expansion tank. The invention also relates to a method of mounting a battery tray on a motor vehicle or on a battery charging device, characterized in that it comprises a step of connecting a link between two connecting means. arranged on a taxiway of a first circuit of a cooling system of the battery tray in which circulates a first coolant, for connecting a first part out of the battery tray of a second part within the tray battery of the cooling system of the battery tray and a second part within the battery tray and a step of securing the battery tray.

The method of mounting a battery tray may include a step of filling the first cooling circuit with coolant. The method of mounting a battery tray may comprise a step of opening a valve under the expansion tank and then a step of circulating a first cooling liquid from the expansion tank by a pump.

These objects, features and advantages of the present invention will be set forth in detail in the following description of a particular embodiment made in a non-limiting manner in relation to the appended figures among which:

FIG. 1 represents a motor vehicle equipped with a battery bank and a cooling system according to the invention.

Figure 2 shows a schematic view of a cooling system of the battery bank according to an embodiment of the invention.

Figure 3 shows a schematic perspective view of a first battery tray including a battery cooling system according to the embodiment of the invention.

Figure 4 shows a schematic perspective view of a second battery tray including a battery cooling system according to the embodiment of the invention. FIG. 5 represents a schematic view of the battery supply cooling system during a disassembly phase of the battery tray according to the embodiment of the invention. Figure 6 shows a schematic view of the battery pack cooling system during a battery tray mounting phase according to the embodiment of the invention.

The concept of the invention is based on the cooling of a battery tank of a motor vehicle by the combination of a dual cooling circuit, the first circuit, mainly out of the battery tray, extending inside. of the battery tank by a removable link arranged at the level of circulation lanes of its coolant and the second circuit, totally integrated in the battery tank, yielding the heat coming from the batteries to the coolant of the first circuit by a heat exchanger arranged within the battery tray. The invention will be more precisely presented using a particular embodiment.

FIG. 1 represents a motor vehicle 1 equipped with a battery tray 2, removably attached under its chassis 3 and connected to an electric traction drive means 4, of the traction type, by an electrical connection 5. The removable connection of the battery tray 2 with the motor vehicle is based on a mechanism not shown, requiring a constraint in a vertical direction to disengage the mechanism in order to actuate a latch in rotation about a substantially vertical axis, to finally unlock and release the battery tray 2, become free to move downward relative to the vehicle, in a substantially vertical direction. Its attachment to the vehicle is done in the reverse stages by the same mechanism. Alternatively, the battery tray 2 could be fixed in a different housing on the motor vehicle, at the trunk for example, and / or by a different mechanism.

According to the concept of the invention, the vehicle 1 further comprises a cooling system of the battery tray 2 which comprises a first portion 10 disposed within the motor vehicle and a second portion 20 disposed within the battery tray. These two parts 10, 20 comprise connecting means for removably connecting them, in a sealed connection 30 located level of the vehicle body. The assembly and disassembly of the battery tray on the motor vehicle causes the automatic connection and disconnection of this link 30, according to a mounting / dismounting process which will be detailed later.

Figure 2 shows more precisely the battery cooling system according to the embodiment of the invention.

This cooling system comprises a first portion 10 mounted within the motor vehicle. This first part 10 mainly comprises a part of a first circuit 11 in which circulates a first cooling liquid. This first circuit 11 is equipped with a first exchanger 12, which consists of a front radiator of the motor vehicle, which is suitable for cooling the first cooling liquid when the ambient temperature is low. It further comprises a second exchanger 13, which cooperates with the air conditioning circuit 6 of the motor vehicle, so as to be able to cool the first coolant, especially when the ambient temperature is high. In addition, an expansion tank 14 performs a function of storing and filling the first circuit 11 with coolant. It extends vertically and is connected to the first circuit 11 at the same time by its upper part and its lower part. A first valve 15 makes it possible to cut off the circulation of the first cooling liquid in the first exchanger 12 and / or in the second exchanger 13. A second valve 16 makes it possible to cut off the circulation of the cooling liquid through the expansion tank 14. Alternatively, a single valve could fulfill the function of the two valves 15, 16. The first circuit 11 also comprises a first pump 17 which ensures the circulation of the first coolant throughout the loop. It includes a second pump 18 whose function is the emptying of the circuit, as will be detailed later. Finally, the first circuit 11 is truncated and comprises connecting means 19, arranged on the flow paths of the first cooling liquid, in order to cooperate with the second part 20 of the cooling system which comprises in particular the missing part of the first circuit 11. .

This second portion 20 of the cooling system is mounted inside the battery tray 2. The latter is in the form of a compartment 7 incorporating one or more batteries 8 and comprising a second cooling circuit 21 in which circulates a second coolant. The battery tray 2 further comprises an exchanger 22 which allows the first cooling liquid from the first circuit 11, cooled in the first part 10 of the cooling system, to cool the second cooling liquid of the battery tray. According to the embodiment, this exchanger 22 is of the "plate" type, oriented vertically, in which the first cooling liquid flows from bottom to top. This vertical positioning of the exchanger facilitates the method of mounting or dismounting the battery tray, which will be described later. Finally, the second portion 20 of the cooling system further comprises two connecting means 29 which cooperate with the connecting means 19 of the first part 10, to form a first closed circulation circuit 11 for the first coolant when the tank battery 2 is mounted on the motor vehicle.

The connecting means 19, 29 of respectively the first part 10 and the second part 20 of the cooling system make it possible to make the battery tray removable. They can be in a very simple form, similar to the sealed connections used for garden hoses, which allows an automatic implementation of the method of mounting and / or disassembly of the battery tray on the motor vehicle. When they are connected to each other in the position of fixing the battery tray on the motor vehicle, they provide a sealed connection 30 which allows the circulation of the first cooling liquid.

Thus, during the operation of the motor vehicle, the first coolant is cooled in the first circuit 11, before cooling the second coolant within the exchanger 22 of the battery tray, which itself circulates around the batteries 8 to cool them. Note, when the ambient temperature is cold, the valve 15 is first closed to allow the heating of the battery at first. On the contrary, when the ambient temperature and hot, the valve 15 closes the channel comprising the radiator 12 and uses the exchanger 13 connected to the air conditioning loop 6 to ensure cooling of the first cooling liquid. Between these two situations, when the ambient temperature is neither too cold nor too hot, the front radiator or exchanger 12 is sufficient for cooling the first coolant.

Figures 3 and 4 illustrate two examples of architecture of a battery tray according to the invention. The first example of FIG. 3 is in the form of the association of two stacks of flat modules, forming a set of dimension substantially equal to 120 × 120 × 30 centimeters, whereas the second example of FIG. stacks of superimposed modules. In both cases, the part added to the battery tank belonging to the cooling system according to the invention, essentially comprising the heat exchanger 22 and a circulation pump 23 for the second cooling liquid, is integrated in a lateral part of the cooling block. The invention also relates to a method of mounting or dismounting a battery tray on a motor vehicle equipped with a cooling system of the battery tray according to the invention. Such a method of disassembling a battery tray when the batteries are discharged must eliminate or limit any leakage of the first coolant of the first circuit that is open during operation.

Thus, when the battery tray is unloaded, the motor vehicle is driven into a battery exchange station. It is positioned above an automatic exchange device, operated by a robot that disassembles the empty battery tray and refit a loaded battery tray. However, before disassembly of a battery tank, the first cooling circuit 11 is at least partially drained before the connection 30 of the first circuit 11 is disconnected to prevent any flow of the first cooling liquid.

For this, during a disassembly phase of a battery tray, the valve 15 of the cooling circuit 11 is first closed to cut the flow of the first coolant in the exchangers 12, 13. On the other hand , the pump 17 is stopped while the second pump 18 is turned on to suck the first coolant which is in the exchanger 22 of the battery tray 2 as well as in the traffic lanes. By this operation, the coolant is sucked into the expansion tank 14, in an inverted circulation direction, and replaced by the air contained in the latter, which flows to the exchanger 22 and the various channels of circulation. FIG. 5 illustrates this phase prior to the mechanical dismantling of the battery tray 2, on which the cooling liquid whose level rises within the expansion tank 14 in the direction d is distinguished. As soon as the pump 18 begins to suck air, the valve 16 is immediately closed, to keep the first cooling liquid within the expansion tank 14. The circulation lanes of the first cooling circuit 11 within the tank of battery 2 are thus filled with air and emptying of cooling liquid. Following this preliminary emptying, the battery tray is then mechanically removed from the motor vehicle, including the step of disconnecting the connection 30 by separation of the connecting means 19, 29.

During a mounting phase of a new battery tray, the tray is mechanically attached to the motor vehicle. During this fixing phase, the connecting means 19, 29 of the two parts 10, 20 of the cooling system are automatically connected. Then, the cooling circuit thus formed is filled with the first cooling liquid. For this, the valve 16 is first opened to allow filling the lower part of the cooling circuit, from the coolant stored in the expansion tank 14, which flows naturally in the lower part of the circuit by single gravity, in the direction b, as shown in Figure 6. When the liquid has reached the pump 17, the latter is started, which causes the circulation of the coolant to the exchanger 22 of the tank of drums. At the same time, the circuit is purged of the air which is there, which returns to the expansion tank 14, until reaching the operating configuration, in which the valve 15 is open.

It appears in the steps of the method of assembly and disassembly of the battery tray that the expansion tank, which comprises a mixture of air and coolant, makes it possible to fulfill the functions of emptying and filling the first cooling circuit. .

Note, when the battery tray is removed from the motor vehicle, it undergoes a charging phase within a battery charging station. During this charging phase, a battery cooling system according to the invention can also be implemented. For this, it is possible to use a cooling system in the battery charging station, the first portion 10 is integrated within the charging device, similarly to that of a motor vehicle as described herein below. above. Thus, the invention also relates to a battery charging device equipped with a battery cooling system according to the invention.

The management of the method of assembly and disassembly of the battery tray, as well as the operation of the cooling system according to the invention is carried out using software and / or hardware means, for example a computer, for controlling the various components of the battery. system.

The coolant used in the described cooling system may be simply water, or any other liquid whose thermal properties are considered to be of interest. The invention advantageously makes it possible to use two liquids, which makes it possible to achieve a higher heat exchange performance than the use of gas. As an alternative embodiment, the second integrated cooling circuit within the battery tray for directly cooling the battery (s) may take any other form, with any thermal fluid, not necessarily liquid, cooled by an exchange with the first liquid cooling within the battery tray.

The invention has been described from a battery tray comprising several separate separate battery modules. Naturally, it applies regardless of the number of modules, even for a single module. In addition, it is apparent from the description of the previous embodiment that alternative embodiments of the cooling system are possible, in particular by deporting certain components of the first part on the second part of the cooling system, such as a pump, a valve ...

Despite the process of draining the coolant during the process of mounting or dismounting the battery tray, there may be a loss of a few drops. Thus, we can associate with this solution a garden valve to eliminate any loss of water. It is also possible to provide a coolant level sensor and provide exceptional addition in case of lack, in a simple maintenance and accessible to any driver.

On the other hand, the invention is particularly suitable for a removable battery tray, allowing its disassembly of a motor vehicle for loading into a specific charging station. Naturally, the described cooling system remains effective in the case of a non removable battery tray.

The solution of the invention finally has the following advantages: it has a very good heat exchange due to the possibility of using coolants, which have a better performance than air; it is perfectly adapted to vehicles with removable battery, in particular by a vertical translation movement.

Claims (15)

1. A cooling system for battery tray (2) for a motor vehicle, comprising a first portion (10) out of the battery tray (2) and a second portion (20) inside the battery tray, characterized in that the first part (10) comprises: - a first truncated circuit (11) cooling a first cooling liquid and - first connection means (19) arranged on a traffic lane of the first circuit (11), and the second part (20) comprises: - second connection means (29) cooperating with the first connecting means (19) in a removable manner to form a connection (30) able to close or open the first circuit (11) circulation, - an exchanger (22) in which circulates the first cooling liquid to cool a second cooling fluid, - a second circuit (21) in which circulates the second cooling fluid for cooling at least one battery (8) of the battery tray e. 2. First part (10) of a cooling system for battery tray (2) for a motor vehicle, characterized in that it comprises a truncated first circuit (11) cooling a first coolant and first connecting means (19) arranged on a taxiway of the first circuit (11). 3. First part (10) of a cooling system for battery tray (2) for a motor vehicle according to claim 2, characterized in that it comprises an expansion tank (14) forming a reservoir for the first liquid of cooling. 4. Part 1 (10) of a cooling system for battery tray (2) for a motor vehicle according to the preceding claim, characterized in that it comprises a valve (16) on the track comprising the expansion tank under this expansion vessel for opening or closing the flow of liquid in the expansion vessel (14). 5. Part 1 (10) of a cooling system for battery tray (2) for a motor vehicle according to the preceding claim, characterized in that it comprises a first pump (16) on the track comprising the expansion tank (14) under this expansion vessel and a second pump (17) near a connecting means (19) forming the outlet of the first portion (10) for the first coolant. 6. Motor vehicle or battery charging device, characterized in that it comprises a first portion (10) of a cooling system for battery tray (2) of a motor vehicle according to one of claims 2 to 5. 7. battery tray (2) for a motor vehicle comprising at least one battery (8), characterized in that it comprises second connecting means (29) arranged on a running lane of a first circuit (11), an exchanger (22) in which circulates a first coolant of the first circuit (11) for cooling a second cooling fluid, and a second cooling circuit (21) in which the second cooling fluid circulates to cool the at least one battery (8). 8. Cooling system for battery tray (2) for a motor vehicle according to claim 1, characterized in that it comprises a first part (10) according to one of claims 2 to 5 and a battery tray (2) according to claim 7. 9. Motor vehicle, comprising a battery tray (2) for supplying its drive motor, characterized in that it comprises a cooling system of its battery tray (2) according to the preceding claim. 10. A method of dismounting a battery tray (2) of a motor vehicle or a battery charging device, characterized in that it comprises a step of disconnecting a link (30) between two means link (19, 29) arranged on a taxiway of a first circuit (11) of a cooling system of the battery tank (2) in which a first cooling liquid circulates, for separating a first part (10) ) outside the battery tray (2) of a second part (20) within the battery tray (2) of the cooling system of the battery tray (2) and in that it comprises a step of separating the tray battery (2). 11. A method of disassembling a battery tray (2) of a motor vehicle or a battery charging device according to the preceding claim, characterized in that it comprises a step of draining at least partially the first circuit (11) of the cooling system of the battery tank (2) of the first coolant. 12. A method of disassembling a battery tray (2) of a motor vehicle or a battery charging device according to the preceding claim, characterized in that the step of draining the coolant comprises the suction by a pump (18) of the coolant into an expansion tank (14), then closing a valve (16) to hold it in this expansion tank (14). 13. A method of mounting a battery tray (2) on a motor vehicle or on a battery charging device, characterized in that it comprises a step of connecting a link (30) between two connecting means (19, 29) arranged on a taxiway of a first circuit (11) of a cooling system of the battery tray (2) in which circulates a first cooling liquid, for connecting a first portion (10) out battery tray (2) of a second part (20) within the battery tray (2) of the battery tray cooling system (2) and a second part (20) within the battery tray (2) ) and a step of securing the battery tray (2). 14. A method of mounting a battery tray (2) on a motor vehicle or on a battery charging device according to the preceding claim, characterized in that it comprises a step of filling the first circuit (11) of coolant cooling. 15. A method of mounting a battery tray (2) on a motor vehicle or on a battery charging device according to the preceding claim, characterized in that it comprises a step of opening a valve (16). under the expansion tank (14) and then a step of circulating a first cooling liquid from the expansion tank (14) by a pump (17).