FR3140799A1 - motor vehicle with heated floor - Google Patents

Abstract

The invention relates to an electrified motor vehicle (1) comprising an electric traction battery (12) located under a floor (11) of a passenger compartment (10) of the motor vehicle (1) and a tank (13) for a washing liquid. -ice extending under the floor (11), the tank (13) being thermally coupled, on the one hand, with the electric traction battery (12) – directly or indirectly – and, on the other hand, with the floor (11) of the passenger compartment (10) – directly or indirectly. Figure to be published with the abstract: Fig. 1

Description

motor vehicle with heated floor

The technical context of the present invention is that of thermal comfort in a motor vehicle passenger compartment, and in particular thermal management systems for motor vehicles of the electrified type. More particularly, the invention relates to an electrified motor vehicle comprising a heated floor.

In the state of the art, heating and air conditioning systems are known which make it possible to regulate a temperature in the passenger compartment of a motor vehicle. Such heating and air conditioning systems include:

– an inlet flap located at the front of the motor vehicle and allowing fresh air from the outside to be injected into the heating and air conditioning system;

– a heating, ventilation and air conditioning unit, known by the English acronym HVAC meaning “Heating, Ventilation and Air-Conditioning” which makes it possible to produce temperature-regulated air – hot or cold – and to control a flow in the direction of passenger compartment;

– interior shutters located in the passenger compartment, typically near a windshield and glass walls of the motor vehicle, at the level of an upper part of a dashboard in order to blow the regulated air in the direction of a driver and/or a passenger, and at a lower part of the dashboard in order to blow the regulated air towards the feet of the driver and/or passengers;

– an air extractor located at the rear of the motor vehicle and allowing stale air to be extracted from the passenger compartment in order to be able to renew it.

Such heating and ventilation systems are particularly energy-intensive, because the heating, ventilation and air conditioning unit requires a high electrical input to be able to operate, despite the ease of heat production in thermal motor vehicles due to the thermal engine located in the engine compartment.

On the other hand, electrified motor vehicles, and in particular electric motor vehicles, do not have such a heat source making it possible to easily heat the air blown into the passenger compartment, since they do not have a thermal engine and the electric motor(s) do not do not produce enough calories to be able to use them for the thermal regulation of the passenger compartment.

Also, the electrical energy necessary for the operation of a heating, ventilation and air conditioning unit of an electrified motor vehicle must be taken from the electric traction battery of said motor vehicle, significantly reducing its autonomy. A loss of autonomy of around 35% is estimated when the heating, ventilation and air conditioning unit is used to cool the air or dehumidify, in hot or cold climates.

Furthermore, as is known, for the majority of journeys made, only one or two passengers are present in motor vehicles, obviously placed in the front seats. This results in a certain lack of optimization of the thermal regulation of the passenger compartment, since the latter is always heated or cooled entirely even in the event of partial occupancy. Such passenger compartments have a volume of around 2m3 while only the m3 associated with the front seats could be regulated in the vast majority of usage situations.

This results in a lack of performance and difficulty in thermally regulating the passenger compartment, leading to a feeling of thermal discomfort for its occupants.

The object of the present invention is to propose a new motor vehicle in order to respond at least largely to the preceding problems and also to lead to other advantages.

Another aim of the invention is to improve the thermal comfort of the occupants of such a motor vehicle.

Another aim of the invention is to facilitate the heating in such a motor vehicle, by reducing thermal discomfort upon starting the motor vehicle.

Another aim of the invention is to reduce the electrical consumption necessary in particular for heating the passenger compartment of such a motor vehicle.

According to a first aspect of the invention, at least one of the aforementioned objectives is achieved with an electrified motor vehicle comprising an electric traction battery located under a floor of a passenger compartment of the motor vehicle and a reservoir for a windshield washer fluid. extending under the floor, the tank being thermally coupled, on the one hand, with the electric traction battery and, on the other hand, with the floor of the passenger compartment.

In the context of the present invention, the longitudinal axis, the lateral axis and the vertical axis are defined relative to the motor vehicle. More particularly, the transverse axis is understood as a direction taken between a lateral side of the motor vehicle and an opposite lateral side of said motor vehicle. In other words, the transverse axis is understood in a direction which extends from a passenger side of the motor vehicle towards a driver's side of said motor vehicle, or vice versa. The adjectives lateral, interior and exterior refer to such a transverse axis. Additionally, the longitudinal axis extends as taken along a direction that extends from front to rear or rear to front of the motor vehicle. The longitudinal axis is perpendicular to the transverse axis. The adjectives frontal, front and rear refer to this longitudinal axis. Finally, the vertical axis is understood as being taken along an axis which extends from the wheels of the motor vehicle and towards the roof of said motor vehicle, or vice versa, the vertical axis being simultaneously perpendicular to the axis transverse and to the longitudinal axis. The adjectives above and below, or inferior and superior refer to this vertical axis.

In the context of the present invention, an electrified motor vehicle is of the type of an electric or hybrid motor vehicle. Generally speaking, a traction chain of such an electrified motor vehicle is rotated by an electric machine, electrically powered by the electric traction battery, in order to generate a motor torque used to set the motor vehicle in motion. . Complementarily or alternatively, the electric machine is configured to recover mechanical energy from the traction chain and convert it into electrical energy, thus producing a braking torque on said traction chain and making it possible to recharge the electric traction battery.

In the context of the present invention, the electric traction battery is a high voltage electric battery making it possible to generate a direct voltage of at least 300V, for example equal to 400V or 800V. Generally speaking, the electric traction battery is configured to supply electrical energy to an electric machine generating a motor torque on the traction chain of the motor vehicle.

In the context of the present invention, the windshield washer fluid is a mixture comprising water and/or an alcohol making it possible to clean the windshield of the motor vehicle via a windshield wiping system. broken. Additionally, such a windshield washer fluid can also be used to clean the rear window of a hatchback motor vehicle and/or on headlight optics.

In the context of the present invention, the windshield washer fluid reservoir forms a container in fluid communication with the wiping system in order to be able to extract a predetermined quantity of the windshield washer fluid used to clean the windshield. In a known manner, the tank has an interior volume of between 2.5 L and 5.5 L.

In the context of the present invention, the floor of the passenger compartment is the wall delimiting a lower zone of the passenger compartment, relative to the vertical axis. In particular, in an electrified motor vehicle, the floor is the wall separating the passenger compartment from the area located below and at which the electric traction battery is located.

In the context of the present invention, thermal coupling is understood as a mechanical, structural and functional organization which aims to organize a heat transfer between two thermally coupled parts. Thermal coupling thus consists of establishing a structural connection between the two parts so as to make heat transfer between them possible and effective.

Thus, in the motor vehicle conforming to the first aspect of the invention, the tank is not located in the engine compartment, as is generally the case, but it is located under the passenger compartment and in an intermediate position between the electric traction battery and the passenger compartment, relative to the vertical axis. The invention uses in a particularly clever manner the reservoir and the windshield washer fluid it contains as a heat storage space making it possible to preserve for a longer period the calories produced by the electric traction battery during its charge.

Indeed, in a known manner, the charging of the electric traction battery, whether slow or fast, leads to an exothermic reaction on the part of the electric traction battery. Generally, the calories thus produced are evacuated or not used and dissipated naturally. Conversely, the invention according to its first aspect aims to exploit these calories to authorize heating of the floor of the motor vehicle during charging of the electric traction battery. Thus, when the user of the motor vehicle enters the motor vehicle after recharging, the floor of the passenger compartment has been heated and the passenger compartment is less cold than without the invention.

Thus, the motor vehicle conforming to the first aspect of the invention makes it possible to improve thermal comfort in the passenger compartment, by allowing heating without electrical consumption.

The motor vehicle conforming to the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:

– according to a first alternative embodiment, the tank is thermally coupled directly with the electric traction battery, a wall of the tank bearing against one face of the electric traction battery or a box housing said electric traction battery . By direct coupling, we understand that part of the tank rests against one side of the electric traction battery or the box housing it. Thus, the calories produced by the electric traction battery during its recharge are transferred by thermal conduction towards the tank and the windshield washer fluid it contains.

– alternatively, according to a second embodiment, the tank is coupled indirectly with the electric traction battery, the motor vehicle comprising a thermal coupling device placed in an intermediate position between the tank and the electric traction battery, the device thermal coupling being thermally coupled to the electric traction battery and to the tank. By indirect coupling, we understand that the thermal coupling device is placed between a part of the tank and the face of the electric traction battery or the box housing it. Thus, the calories produced by the electric traction battery during its recharge are transferred by thermal conduction towards the reservoir and the windshield washer fluid it contains via the thermal coupling device. Such a thermal coupling device can take any shape, depending on the geometry of the tank and the electric traction battery, or the space available under the floor of the motor vehicle. Generally speaking, the thermal coupling device comprises any element making it possible to transfer the calories generated at the level of the electric traction battery towards the tank, by thermal conduction, by convection or by any mode of propagation of the calories ;

– particularly advantageously, the thermal coupling device comprises a heat pipe and/or a deflector and/or a thermal tab making it possible to improve the thermal contact between the electric traction battery and the tank. In the context of the invention, the heat pipe is a set of heat-conducting elements housing a fluid in equilibrium under two phases, liquid and gas. The fluid housed in the heat pipe thus makes it possible to transport the calories captured at a first end of the heat pipe, thermally coupled to the electric traction battery, towards a second end thermally coupled to the reservoir, by phase transition of the fluid;

– according to a first embodiment compatible with any of the variants mentioned above, the tank is thermally coupled directly with the floor of the passenger compartment, one wall of the tank resting against the floor. By direct coupling, we understand that part of the tank is resting against the floor of the passenger compartment. Thus, the calories temporarily stored in the tank, following recharging of the electric traction battery, are transferred by thermal conduction towards the floor.

– according to a second embodiment compatible with any of the variants mentioned above, the tank is coupled indirectly with the floor, the motor vehicle comprising a thermal coupling member placed in an intermediate position between the tank and the floor and thermally coupled to them. By indirect coupling, we understand that the thermal coupling member is placed between a part of the tank and the floor. Thus, the calories temporarily stored in the tank, following recharging of the electric traction battery, are transferred by thermal conduction towards the floor via the thermal coupling member. Such a thermal coupling member can take any shape, depending on the geometry of the tank and the floor, or the space available under said floor. Generally speaking, the thermal coupling member comprises any element making it possible to transfer the calories stored in the tank towards the floor, by thermal conduction, by thermal convection or by any mode of propagation of the calories;

– particularly advantageously, the thermal coupling member comprises a heat pipe and/or a deflector and/or a thermal tab making it possible to improve the thermal contact between the electric traction battery and the tank;

- the tank extends under a row of front seats in the passenger compartment of the motor vehicle, and/or under a row of rear seats in the passenger compartment of the motor vehicle;

- the reservoir has a general parallelepiped shape having a thickness of between 4 cm and 8 cm, preferably equal to 5 cm, taken relative to a vertical axis;

- a width of the tank, taken relative to a transverse axis of the motor vehicle, is between 15 cm and 50 cm;

- a length of the tank, taken relative to a longitudinal axis of the motor vehicle, is less than 1 m.

- the motor vehicle comprises a device for deactivating a thermal coupling between the tank and the electric traction battery, the deactivation device being able to be configured selectively in a thermal coupling configuration in which the tank is thermally coupled to the electric battery of traction, and a thermal insulation configuration in which the tank is thermally decoupled from the electric traction battery. This advantageous configuration thus makes it possible to avoid transferring too many calories to the tank, from the electric traction battery and during its recharge. In fact, when recharging, the temperature of the electric traction battery can exceed 100°C. However, it is not desirable for the windshield washer fluid contained in the reservoir to exceed 70°C. in fact, beyond such a temperature, the alcohol possibly present in the windshield washer fluid could evaporate, reducing the effectiveness of the windshield washer fluid when cleaning the glass walls of the motor vehicle in accordance with the first aspect of the invention, which is not desired. In addition, it is also not desirable to bring the windshield washer fluid above 100°C so as not to evaporate the aqueous phase thereof. Consequently, the deactivation device is configured to thermally uncouple the tank from the electric traction battery when a temperature of or in the tank exceeds a temperature limit of between 50°C and 65°C;

– advantageously, the deactivation device comprises in particular a bistable material making it possible to selectively establish thermal coupling or to thermally uncouple the electric traction battery from the tank as a function of a temperature of said bistable material. Preferably, the bistable material is chosen to be able to switch into one or other of its stable states around the limit temperature defined previously.

Thus, the vehicle conforming to the first aspect of the invention makes it possible to effectively heat the passenger compartment of the motor vehicle and without consuming electrical energy from the electric traction battery, and during its recharge. The invention thus makes it possible to bring the floor of the motor vehicle, by simple thermal coupling – direct or indirect – to a temperature between 20°C and 23°C which makes it possible to significantly improve thermal comfort when a user enters the motor vehicle according to the invention, to limit the feeling of cold when starting the motor vehicle, while avoiding feeling a burning sensation with the floor.

Various embodiments of the invention are planned, integrating according to all of their possible combinations the different optional characteristics exposed here.

Other characteristics and advantages of the invention will appear further through the description which follows on the one hand, and several examples of embodiment given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which :

illustrates a first embodiment of a motor vehicle conforming to the first aspect of the invention;

illustrates a second embodiment of a motor vehicle conforming to the first aspect of the invention;

illustrates a third embodiment of a motor vehicle conforming to the first aspect of the invention;

illustrates a fourth embodiment of a motor vehicle conforming to the first aspect of the invention.

Of course, the characteristics, variants and different embodiments of the invention can be associated with each other, in various combinations, to the extent that they are not incompatible or exclusive of each other. In particular, it will be possible to imagine variants of the invention comprising only a selection of characteristics described subsequently in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from to the prior art.

In particular, all the variants and all the embodiments described can be combined with each other if nothing opposes this combination on a technical level.

In the figures, elements common to several figures retain the same reference.

With reference to FIGURES 1 to 4, the invention addresses an electrified motor vehicle 1, that is to say of the electric type or of the hybrid type, comprising an electric traction battery 12 located under a floor 11 of a passenger compartment 10 of the motor vehicle 1 and a reservoir 13 for a windshield washer fluid also extending under the floor 11, the reservoir 13 being thermally coupled, on the one hand, with the electric traction battery 12 and, on the other hand, with the floor 11 of the passenger compartment 10.

Tank 13 is located under floor 11 and above electric traction battery 12.

Thus, when the electric traction battery 12 is being recharged, that is to say when it is electrically connected to a charging station 2 via a charging cable 3, then the transfer of The electrical energy in the direction of the electric traction battery 12 is accompanied by an exothermic reaction at the level of the electric traction battery 12. Calories thus generated at the level of the electric traction battery 12 are then transferred, mainly by conduction thermal, between the electric traction battery 12 and the tank 13 located nearby and in thermal coupling with the electric traction battery 12.

The calories transferred to the reservoir 13 are then transmitted to the windshield washer fluid contained in said reservoir 13. If the reservoir 13 is mostly full, then the windshield washer fluid plays the role of temporary heat storage. If the reservoir 13 is lightly filled with windshield washer fluid, then it is the reservoir 13 itself, the air contained in the reservoir 13 and the portion of windshield washer fluid contained in the reservoir 13 which play the role of temporary heat storage.

These calories thus heat the tank 13 and its contents, windshield washer fluid or air.

Consequently, as the tank 13 is also thermally coupled to the floor 11 of the passenger compartment 10, the calories stored in and by the tank 13 are transferred to the floor 11 of the passenger compartment 10 by thermal conduction. The floor 11 can then rise in temperature and heat the passenger compartment 10 by convection.

Thus, during charging, if the temperature of the electric traction battery 12 reaches 100°C or more, it is possible, through such a heat transfer, to organize a rise in temperature of the floor 11 of several tens of degrees.

A temperature between 20 and 23°C is considered optimal at the level of the floor 11 of the passenger compartment 10 in order to sufficiently heat the floor 11 to provide a feeling of comfort at the level of the feet for the user of the motor vehicle 1 who enters. in the motor vehicle 1 once the electrical charge is complete, while avoiding bringing said floor 11 to too high a temperature which would cause a feeling of discomfort or even almost burning in the event of direct contact with the floor 11.

In order to organize this heat transfer by thermal conduction between the electric traction battery 12 and the floor 11 of the passenger compartment 10 of the motor vehicle 1, several configurations are provided and illustrated in FIGURES 1 to 4:

– FIGURES 1 and 2 illustrate two different examples of embodiment in which the tank 13 is directly thermally coupled both to the electric traction battery 12 and to the floor 11 of the passenger compartment 10 of the motor vehicle 1. By direct thermal coupling, we understand that the tank 13 is in direct support – or via a thermal tab in order to improve thermal coupling – with a support face of the electric traction battery 12 on the one hand, and with a support face of the floor 11 on the other hand.

– FIGURES 3 and 4 illustrate two other different examples of embodiment in which the tank 13 is indirectly thermally coupled both to the electric traction battery 12 and to the floor 11 of the passenger compartment 10 of the motor vehicle 1. By indirect thermal coupling , we understand that the tank 13 is not in direct support with a face facing the electric traction battery 12 on the one hand or the floor 11. Conversely, the heat transfer between the electric battery and the tank 13 d 'on the one hand, then between the tank 13 and the floor 11 on the other hand, is ensured by means of an intermediate part. More particularly, in the exemplary embodiments illustrated in FIGURES 3 and 4, the motor vehicle 1 comprises a thermal coupling device 14 placed in an intermediate position between the tank 13 and the electric traction battery 12, the thermal coupling device 14 being thermally coupled to the electric traction battery 12 and to the tank 13; and the motor vehicle 1 comprises a coupling member 15 placed in an intermediate position between the tank 13 and the floor 11 and thermally coupled to them.

Of course, in the context of the present invention, all coupling combinations – direct or indirect – are provided between the electric traction battery 12 and the tank 13 on the one hand and between the tank 13 and the floor 11 on the other. go.

Additionally, the tank 13 can extend under all or part of the floor 11 of the passenger compartment 10 of the motor vehicle 1. In particular, as visible in FIGURES 1 and 3, the tank 13 can extend mainly under the seats of row 1 of the motor vehicle 1, that is to say under a floor 11 located at the level of the front seats of the passenger compartment 10.

Alternatively or additionally, as visible in FIGURES 2 and 4, the tank 13 can extend mainly under row 2 seats of the motor vehicle 1, that is to say under a floor 11 located at the level of the rear seats of the passenger compartment 10.

Preferably, the tank 13 extends between two side wings of the motor vehicle 1, in order to provide heating of the floor 11 evenly between the two side edges of the passenger compartment 10 of the motor vehicle 1.

In summary, the invention relates to an electrified motor vehicle 1 comprising an electric traction battery 12 located under a floor 11 of a passenger compartment 10 of the motor vehicle 1 and a reservoir 13 for a windshield washer fluid extending under the floor 11 , the tank 13 being thermally coupled, on the one hand, with the electric traction battery 12 – directly or indirectly – and, on the other hand, with the floor 11 of the passenger compartment 10 – directly or indirectly.

Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the different characteristics, shapes, variants and embodiments of the invention can be associated with each other in various combinations to the extent that they are not incompatible or exclusive of each other. In particular, all the variants and embodiments described above can be combined with each other.

Claims (9)

Electrified motor vehicle (1) comprising an electric traction battery (12) located under a floor (11) of a passenger compartment (10) of the motor vehicle (1) and a reservoir (13) for a windshield washer fluid extending under the floor (11), the tank (13) being thermally coupled, on the one hand, with the electric traction battery (12) and, on the other hand, with the floor (11) of the passenger compartment (10) . Motor vehicle (1) according to claim 1, in which the tank (13) is thermally coupled directly with the floor (11) of the passenger compartment (10), a wall of the tank (13) bearing against the floor (11). Motor vehicle (1) according to claim 1, in which the tank (13) is coupled indirectly with the floor (11), the motor vehicle (1) comprising a thermal coupling member (15) placed in an intermediate position between the tank (13) and the floor (11) and thermally coupled to them. Motor vehicle (1) according to any one of claims 1 to 3, in which the tank (13) is thermally coupled directly with the electric traction battery (12), a wall of the tank (13) being supported against a face of the electric traction battery (12) or of a housing housing said electric traction battery (12). Motor vehicle (1) according to any one of claims 1 to 3, in which the tank (13) is coupled indirectly with the electric traction battery (12), the motor vehicle (1) comprising a thermal coupling device (14) placed in an intermediate position between the tank (13) and the electric traction battery (12), the thermal coupling device (14) being thermally coupled to the electric traction battery (12) and to the tank (13) . Motor vehicle (1) according to the preceding claim, in which the thermal coupling device (14) comprises a heat pipe and/or a deflector. Motor vehicle (1) according to any one of the preceding claims, in which the tank (13) extends under a row of front seats of the passenger compartment (10) of the motor vehicle (1), and/or under a row rear seats of the passenger compartment (10) of the motor vehicle (1) Motor vehicle (1) according to any one of the preceding claims, in which the motor vehicle (1) comprises a device for deactivating a thermal coupling between the tank (13) and the electric traction battery (12), the device deactivation can be selectively configured in a thermal coupling configuration in which the tank (13) is thermally coupled to the electric traction battery (12), and a thermal insulation configuration in which the tank (13) is thermally decoupled from the electric traction battery (12). Motor vehicle (1) according to the preceding claim, in which the deactivation device comprises in particular a bistable material making it possible to selectively establish a thermal coupling or to thermally uncouple the electric traction battery (12) from the tank (13) as a function of a temperature of said bistable material.