DEVICE CONFIGURED TO TEST THE TIGHTNESS OF A COOLING CIRCUIT OF A BATTERY CASE AND ASSOCIATED METHOD

Abstract

The invention relates to a device (100) configured to test the tightness of a cooling circuit of a battery box (200) of an electric or hybrid motor vehicle, said battery box (200) comprising a plurality of accumulators (4) arranged in rows and a plurality of crosspieces (5) between each row, characterized in that said cooling circuit comprises an injection network comprising a plurality of rails (6) of which each rail (6) comprises a channel (7) capable of transporting a dielectric fluid, each channel (7) comprising a plurality of nozzles (8), said device (100) comprising a plurality of semi-circular gutters (1) connected to each other by flat surfaces (2), each gutter (1) being intended to entirely cover one of the channels (6) and each gutter (1) comprising one end comprising a pressure sensor. Figure 2

Description

Title of the invention: DEVICE CONFIGURED TO TEST THE TIGHTNESS OF A COOLING CIRCUIT OF A BATTERY CASE AND ASSOCIATED METHOD

[0001] The invention relates to motor vehicles with partially or fully electric propulsion, and more particularly to the battery boxes of these vehicles and their cooling.

[0002] Known from the prior art is a patent application KR100969065 which describes a method for checking the airtightness of a fuel cell during its assembly. The method consists of injecting a cooling fluid, in a gaseous or liquid state, into the cooling circuit of the fuel cell in order to measure a pressure variation during the passage of said fluid. If the pressure variation is within a range of predetermined standard values, then there is no leak. If the pressure variation is greater than a threshold value, then there is a leak in the cooling circuit of the fuel cell. The patent application also relates to a device comprising a press for exerting pressure on said fuel cell. The press comprises a plurality of openings allowing the injection of the cooling fluid.The device comprises a gas supply pipe located at the inlet of the openings and a valve allowing the opening or closing, completely or partially, of said gas supply pipe. In addition, the device comprises pressure sensors. The device allows the implementation of the method previously described. However, a disadvantage remains. Indeed, the cooling circuit only has a single pressure sensor, which only gives an overall measurement of the pressure within the cooling circuit. Consequently, if a fluid leak is detected, then it is impossible to locate it. Other tests will have to be implemented to locate said leak, which represents a waste of time.

[0003] The objective of the present invention is to remedy these drawbacks by proposing a device for checking the tightness of a cooling circuit of a battery tray and for locating the leak when it is detected.

[0004] To achieve this objective, the invention proposes a device configured to test the tightness of a cooling circuit of a battery box of an electric or hybrid motor vehicle, said battery box comprising a plurality of accumulators arranged in rows and a plurality of crosspieces between each row, remarkable in that said cooling circuit comprises an injection network comprising a plurality of rails, each rail of which comprises a channel capable of transporting a dielectric fluid, each channel comprising a plurality of nozzles, said device comprising a plurality of semi-circular shaped gutters connected to each other by flat surfaces, each gutter being intended to entirely cover one of the channels and each gutter comprising an end comprising a pressure sensor.

[0005] Thanks to the invention, it is possible to detect a possible leak precisely before the final assembly of the battery tray.

[0006] Advantageously, each gutter has a height of between 10 mm and 30 mm, preferably 20 mm.

[0007] Advantageously, each gutter has a width of between 20 mm and 40 mm, preferably 30 mm.

[0008] These dimensions allow easy positioning of said device on the channels of a standard battery tray.

[0009] Advantageously, each gutter has four edges, each edge comprising a sealing gasket.

[0010] This configuration makes it possible to avoid gas leaks during the leak test, which would distort the test.

[0011] Advantageously, each gutter has four edges, each edge comprising a sealing foam.

[0012] Advantageously, said injection network comprises at least four channels, each channel comprising at least four nozzles.

[0013] Preferably, said injection network comprises seven channels, each channel comprising seven nozzles.

[0014] Furthermore, the invention relates to a method for checking the tightness of a cooling circuit of a battery tray using said device previously described, remarkable in that a gutter (1) covering a tight channel has a predetermined pressure value, said method comprising the following steps: - a step of placing said device on said channels of the battery tray; - a step of injecting a gas into the injection network for a predetermined time; - a step of continuous measurement of the pressure in each channel by the pressure sensors; - a step of comparing each measured pressure value with said determined pressure value, said cooling circuit being sealed when the measured pressure value is equal to the predetermined pressure value.

[0015] Furthermore, the invention relates to a battery tray which is remarkable in that said battery tray comprises a cooling circuit whose sealing is capable of being controlled by said device previously described.

[0016] Finally, the invention also relates to an electric or hybrid motor vehicle characterized in that said vehicle comprises a battery box described above.

[0017] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which: - [Fig.l] schematically illustrates a device configured to test the tightness of a cooling circuit of a battery tray of an electric or hybrid motor vehicle according to one embodiment of the invention; - [Fig.2] schematically illustrates a section along an axial plane of said device positioned on the battery tray; - [Fig.3] schematically illustrates, in the form of a flowchart, a process for checking the tightness of a battery tray cooling circuit.

[0018] [Fig.l] schematically illustrates a battery tray 200 on which a device 100 rests. The device 100 is configured to test the tightness of a cooling circuit of the battery tray 200 during the assembly of said battery tray 200. The battery tray 200 comprises a bottom plate and walls thus creating a housing. A plurality of accumulators is arranged within the housing. All of the accumulators form the vehicle's battery. The battery allows the storage and distribution of electrical energy to the electric motor of a motor vehicle. A cover is added in order to hermetically close the housing. Thus, the battery is not at risk of receiving water splashes for example, which would be likely to damage it and cause a short circuit, and potentially a fire.The battery tray also includes a cooling circuit to prevent the battery from overheating, which could again cause a fire. The cooling circuit consists of spraying a dielectric fluid onto the accumulators via nozzles. Thus, the dielectric fluid spreads between the accumulators to the bottom plate where it is evacuated in order to be cooled. The cooling circuit is a closed circuit, the evacuated fluid therefore returns, after cooling, to the nozzles in order to be sprayed again onto the accumulators. The details of the configuration of the battery tray 200 will be detailed in [Fig. 2]. In [Fig. 1], said device 100 includes a plurality of gutters 1 connected to each other by a plurality of flat surfaces 2. The gutters are arranged so that the nozzles are completely covered. Each gutter 1 has a height of between 10 mm and 30 mm.Preferably, each gutter 1 has a height of 20 mm. In addition, each gutter 1 has a width of between 20 mm and 40 mm. Preferably, each gutter 1 has a width of 30 mm. At the end of each gutter 1 is located a pressure sensor 3. The sensors of . pressure 3 make it possible to determine whether the device 100 has a leak-tightness defect. The method for testing the leak-tightness of the cooling circuit will be described in [Fig. 3]. Advantageously, said device 100 comprises at least four channels 7 comprising at least four nozzles 8 each. Preferably, said device 100 comprises seven channels 7 comprising seven nozzles 8 each.

[0019] [Fig. 2] schematically illustrates a section of said device 100 along an axial plane. The device 100 is arranged on the battery box 200. In [Fig. 2], three accumulators 4 are shown, at least partially. In the battery box 200, the accumulators 4 are arranged in rows. A crosspiece 5 is arranged between each row of accumulators 4. Thus, two crosspieces 5 are shown in [Fig. 2]. The cooling circuit comprises an injection network comprising a plurality of rails 6. Each rail 6 is able to be positioned on one of the crosspieces 5. Each rail 6 comprises a channel in which the dielectric fluid is able to circulate. Each channel comprises a plurality of nozzles 8. In [Fig.2], two channels 7 are shown and each comprises a nozzle 8. The device 100 is positioned on the battery tray 200. In this way, the nozzles 8 are covered by the gutters 1. Each gutter has four edges.To ensure the sealing of each gutter 1, a sealing gasket 9 is arranged on each edge. In an alternative embodiment, each edge comprises a sealing foam. The invention also relates to a battery tray comprising a cooling circuit whose sealing is capable of being controlled by said device 100. Furthermore, the invention relates to an electric or hybrid motor vehicle comprising a battery tray 200 as previously mentioned.

[0020] In [Fig. 3], a method for checking the tightness of a cooling circuit of a battery tray by said device is schematically illustrated in the form of a flowchart. During a placement step E1, said device 100 is positioned on said battery tray 200. All of the nozzles 8 are covered by the gutters 1. During an injection step E2, a gas is injected for a predetermined time into the injection network so that said gas travels in particular through each channel and is evacuated through each nozzle 8. The gas then accumulates in each gutter 1. During a measurement step E3, the pressure sensors 3 of each gutter continuously measure a measured pressure value over said predetermined time. A predetermined pressure value is expected when the pressure is measured by each pressure sensor.The predetermined pressure value corresponds to the value for which it is determined that said channel has no leaks. During a comparison step E4, the pressure value measured for each channel is compared with the predetermined pressure value. If all of the pressure sensors 3 measure an identical pressure value consistent with the predetermined pressure value, . then the device 100 is considered to be perfectly sealed. If at least one of the pressure values ​​measured in one of the gutters 1 varies with respect to the pressure values ​​measured in the other gutters 1, and with respect to said predetermined pressure value, then this means that the device 100 has a sealing defect. In this case, a technician replaces the rail concerned and repeats the sealing test procedure. This prevents the sealing defect from being detected after the complete assembly of the battery tray 200, or even after the assembly of said battery tray 200 in the electric or hybrid motor vehicle, which would result in more work to resolve the sealing problem, and consequently, a greater loss of time.

Claims

Claims

1. Device (100) configured to test the tightness of a cooling circuit of a battery box (200) of an electric or hybrid motor vehicle, said battery box (200) comprising a plurality of accumulators (4) arranged in rows and a plurality of crosspieces (5) between each row, characterized in that said cooling circuit comprises an injection network comprising a plurality of rails (6) of which each rail (6) comprises a channel (7) capable of transporting a dielectric fluid, each channel (7) comprising a plurality of nozzles (8), said device (100) comprising a plurality of semi-circular gutters (1) connected to each other by flat surfaces (2), each gutter (1) being intended to entirely cover one of the channels (6) and each gutter (1) comprising one end comprising a pressure sensor (3).

2. Device (100) according to claim 1 characterized in that each gutter (1) has a height of between 10 mm and 30 mm, preferably 20 mm.

3. Device (100) according to claim 1 or 2 characterized in that each gutter (1) has a width of between 20 mm and 40 mm, preferably 30 mm.

4. Device (100) according to any one of claims 1 to 3 characterized in that each gutter (1) has four edges, each edge comprising a sealing joint (9).

5. Device (100) according to any one of claims 1 to 3 characterized in that each gutter (1) has four edges, each edge comprising a sealing foam.

6. Device (100) according to any one of claims 1 to 5 characterized in that said injection network comprises at least four channels, each channel comprising at least four nozzles.

7. Device (100) according to claim 6 characterized in that said injection network comprises seven channels, each channel comprising seven nozzles.

8. Method for checking the tightness of a cooling circuit of a battery tray (200) implementing said device (100) according to any one of claims 1 to 7, characterized in that a gutter (1) covering a tight channel has a predetermined pressure value, said method comprising the following steps: - a step of placing (El) said device (100) on said channels of the battery tray (200); - a step of injecting (E2) a gas into the injection network for a predetermined time; - a continuous measurement step (E3) of the pressure in each channel (7) by pressure sensors (3); - a step (E4) of comparing each measured pressure value with said predetermined pressure value, said cooling circuit being sealed when the measured pressure value is equal to the predetermined pressure value.

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