WO2019239022A1 - Heating, ventilation and/or air-conditioning device for a motor vehicle comprising at least one mass sensor - Google Patents

Abstract

This invention relates to a heating, ventilation and/or air-conditioning device (1) for a motor vehicle (2), according to which said heating, ventilation and/or air-conditioning device (1) comprises: - a passenger-compartment air filter (10); - at least one mass sensor (11) configured to: - measure a weight (p1) of the passenger-compartment air filter (10) in use; - transmit said weight (p1) to a clogging detection device (3) so that the latter can calculate a weight difference (ΔP) from said weight (p1) and an initial weight (p0) of said passenger-compartment air filter (10) and compare it with a reference weight value (Pref).

Description

 HEATING, VENTILATION AND / OR AIR CONDITIONING DEVICE FOR A MOTOR VEHICLE COMPRISING AT LEAST ONE

MASS SENSOR

TECHNICAL FIELD OF THE INVENTION The present invention relates to a heating, ventilation and / or air conditioning device for a motor vehicle. The invention also relates to a device for detecting clogging of a cabin air filter of a heating, ventilation and / or air conditioning device for a motor vehicle. Finally, the invention also relates to a method for detecting clogging of a cabin air filter of a heating, ventilation and / or air conditioning device for a motor vehicle.

 It finds a particular, but not limiting, application in motor vehicles.

TECHNOLOGICAL BACKGROUND OF THE INVENTION A heating, ventilation and / or air conditioning device known to a person skilled in the art comprises a cabin air filter for ensuring the quality of the cabin air in said motor vehicle.

 A cabin air filter has different layers of filter materials known as filter media. A cabin air filter filters particles and gases. The end of life of a cabin air filter is defined by the clogging (fouling) of the filter media. This clogging corresponds to the moment when the different layers of filtering materials are saturated with particles and no longer allow the passage of sufficient air flow in the passenger compartment.

The lifetime of a cabin air filter is arbitrarily defined on the basis of a number of kilometers traveled by the motor vehicle, for example 15,000 km or once a year and therefore without technical data on the actual use of the cabin air filter by the end user. This arbitrary lifetime does not take into account conditions for using the cabin air filter. Depending on the conditions of use (for example use in a more or less polluted area), the cabin air filter may clog more or less quickly.

 A drawback of this prior art is that the user, such as the owner of the motor vehicle, does not know at what stage of clogging his cabin air filter is located, which can lead him to replace his filter. cabin air more often than necessary or use a cabin air filter that no longer performs its filtering functions.

 In this context, the present invention aims to provide a heating, ventilation and / or air conditioning device which makes it possible to solve the drawback mentioned above.

GENERAL DESCRIPTION OF THE INVENTION

To this end, the invention provides a heating, ventilation and / or air conditioning device for a motor vehicle, according to which said heating, ventilation and / or air conditioning device comprises:

 - a cabin air filter;

 - at least one mass sensor configured for:

 - measure a weight of said cabin air filter during use;

- transmit said weight to a clogging detection device so that the latter can calculate a weight difference from said weight and an initial weight of said cabin air filter and compare it with a reference weight value.

Thus, by measuring the difference in weight of the cabin air filter between its new state (initial weight) and its state in use (measured weight), it can be determined whether the air filter is clogged or not and s '' it has reached its maximum clogging capacity thanks to the comparison of the weight difference with a reference weight value which represents a clogging threshold value. The clogging capacity is in fact a function of the increase in the weight of the cabin air filter due to the accumulation of particles in its filter media. In fact, the more particles accumulated by the filtering media of the cabin air filter, the more the weight of the cabin air filter increases.

 According to non-limiting embodiments, said heating, ventilation and / or air conditioning device for a motor vehicle may further include one or more additional characteristics among the following:

 According to a nonlimiting embodiment, said reference weight value is characteristic of an end of life of said cabin air filter.

 According to a nonlimiting embodiment, said heating, ventilation and / or air conditioning device comprises two or three mass sensors. Two mass sensors are sufficient when the cabin air filter is arranged vertically in the heating, ventilation and / or air conditioning system. Three mass sensors allow three points of contact with the cabin air filter and thus obtain isostatic support.

 According to a nonlimiting embodiment, the measurement of said weight is carried out when said heating, ventilation and / or air conditioning device is switched off.

 According to a nonlimiting embodiment, which said at least one mass sensor is also configured to measure the initial weight of said cabin air filter. This avoids loading the initial weight of said cabin air filter into the clogging detection device into memory.

 A clogging detection device is also proposed for a cabin air filter of a heating, ventilation and / or air conditioning device for a motor vehicle as described above, according to which said clogging detection device is configured. for :

 - receive from at least one mass sensor a weight of said cabin air filter during use;

calculating a difference in weight from said weight and from an initial weight of said cabin air filter; - compare said weight difference with a reference weight value.

 According to a nonlimiting embodiment, said clogging detection device is further configured to generate an alarm if said difference in weight is greater than or equal to said reference weight value.

 According to a nonlimiting embodiment, said initial weight of said cabin air filter is loaded into memory in said clogging detection device.

 There is also proposed a method for detecting clogging of a cabin air filter of a heating, ventilation and / or air conditioning device for a motor vehicle as described above, according to which said method of detecting clogging comprises following steps :

- measurement by at least one mass sensor of a weight of said cabin air filter during use;

 - Calculation by a clogging detection device as described above of a difference in weight from said weight and an initial weight of said cabin air filter;

 - Comparison by said clogging detection device of said weight difference with a reference weight value.

 According to a nonlimiting embodiment, if said weight difference is greater than or equal to said reference weight value, said clogging detection method further comprises the generation of an alarm.

 According to a nonlimiting embodiment, said clogging detection method further comprises the transmission by said at least one mass sensor of said weight to said clogging detection device of said cabin air filter.

BRIEF DESCRIPTION OF THE FIGURES The invention and its various applications will be better understood on reading the following description and on examining the accompanying figures:

 - Figure 1 shows a block diagram of a heating, ventilation and / or air conditioning device for a motor vehicle comprising a cabin air filter and at least one mass sensor, and configured to cooperate with a clogging detection device , according to a first non-limiting embodiment of the invention;

 - Figure 2 shows a block diagram of a heating, ventilation and / or air conditioning device for a motor vehicle comprising a cabin air filter and at least one mass sensor, and configured to cooperate with a clogging detection device , according to a second non-limiting embodiment of the invention;

 - Figure 3 shows a block diagram of the operation of said heating, ventilation and / or air conditioning device of Figure 1;

 - Figure 4 shows a block diagram of the operation of said heating, ventilation and / or air conditioning device of Figure 2;

 - Figure 5 shows a sectional diagram of a cabin air filter in a housing of the heating, ventilation and / or air conditioning device of Figures 1 or 2, which rests on two mass sensors, according to one embodiment not limiting;

 - Figure 6 shows a sectional diagram of a cabin air filter in a housing of the heating, ventilation and / or air conditioning device of Figures 1 or 2, which rests on three mass sensors, according to one embodiment not limiting;

 - Figure 7 schematically shows a clogging curve used to determine the end of life of the cabin air filter of the heating, ventilation and / or air conditioning device of Figures 1 or 2, according to a non-limiting embodiment; and

- Figure 8 schematically shows a method of detecting clogging of the cabin air filter of the heating, ventilation device and / or air conditioning for a motor vehicle of FIGS. 1 or 2, according to a nonlimiting embodiment.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Identical elements, by structure or by function, appearing in different figures keep, unless otherwise specified, the same references.

 The heating, ventilation and / or air conditioning device 1 for a motor vehicle 2 and the clogging detection device 3, according to the invention are described with reference to FIGS. 1 to 7. The heating, ventilation and / or air conditioning device 1 is called HVAC "Heating Ventilation Air Conditioning"), otherwise called HVAC device.

 By motor vehicle is meant any type of motor vehicle.

 For the rest of the description, pressure drop Pa means the reduction in the air flow due to the mechanical resistance to air of the cabin air filter 10.

 • HVAC device

 As illustrated in Figures 1 and 2, the HVAC device includes:

 - a cabin air filter 10;

 - at least one mass sensor 1 1.

 As illustrated in Figures 3 and 4, the HVAC device further comprises an air duct 12, which is an air inlet duct.

 Said HVAC device is configured to receive an air flow F at the inlet, and said cabin air filter 10 is positioned in said air duct 12 so as to process said air flow F at the inlet of said device HVAC.

The HVAC device further comprises a housing 13 configured to receive said cabin air filter 10. This housing 13 illustrated in FIGS. 5 and 6 comprises an opening 130 through which said cabin air filter 10 is inserted, and a bottom 131 to which said at least one mass sensor 11 will be fixed. The HVAC device further comprises a fan (not illustrated) configured to bring the air flow F with a certain air flow q into said HVAC device. The fan can be controlled by the user of the motor vehicle 2 so as to obtain a determined air flow. The determined air flow is controlled by an electronic device or manually.

In a nonlimiting example, there are up to seven possible airflows possible.

 The HVAC device is configured to cooperate with the clogging detection device 3 described later in the description.

 The elements of the HVAC device are described in detail below.

 o Air duct 12

 The air duct 12 is configured to direct the air flow F towards the interior of the passenger compartment 21 of the motor vehicle 2 in order to allow a renewal of the air of said passenger compartment 21. In one embodiment not limiting, the air flow F comes from outside the vehicle 2. In another non-limiting embodiment, the air flow F comes from inside the passenger compartment 21 of the vehicle automobile 2 in the context of air recycling.

 The air circulating in said air duct 12 comprises particles such as dust, pollen, residual fine particles from the combustion of internal combustion engines, the chemical industry, atmospheric pollution, etc.

 o Air filter 10

 Said cabin air filter 10 is configured to filter the air circulating in the air duct 12.

 For this purpose, it comprises a filtering medium 100 illustrated diagrammatically in FIG. 1 configured to retain upstream the particles present in the air flow F. The more said particles accumulate in the filtering medium 10, the more the air flow F will have a hard time crossing it.

The filter medium 100 acts as a brake on the passage of air in the duct 12. Also, the more the cabin air filter 10 accumulates particles, the more it will slow the passage of air. The more particles it accumulates, the more the weight of the filter medium 100 and therefore that of the cabin air filter 10 as a whole. Thus, as it wears out, the cabin air filter 10 will be heavier and heavier until it is completely blocked, in other words clogged.

 The cabin air filter 10 includes an initial weight pO when it is new, that is to say when it has never been used.

 The cabin air filter 10 is disposed in the housing 13 of the HVAC device configured to receive it. Said housing 13 is connected to the air duct 12.

 The cabin air filter 10 is in contact with said at least one mass sensor 11.

 The cabin air filter 10 has four sides and two opposite sides of each other. It is oriented vertically or horizontally in the HVAC device.

 In a first nonlimiting embodiment illustrated in FIG. 5, the cabin air filter 10 is arranged vertically in the HVAC device, namely that when the cabin air filter 10 is installed in the HVAC device, the cabin air filter 10 is inserted and held in a direction parallel to gravity. The cabin air filter 10 is thus maintained either by friction with the side walls of the housing 13 or by abutting against the bottom 131 of the housing 13. In this case, one of its sides is opposite the bottom 131 of the housing 13. Its side is far from the bottom. The cabin air filter 10 thus rests on the edge.

 In a second nonlimiting embodiment illustrated in FIG. 6, the cabin air filter 10 is arranged horizontally in the HVAC device, namely when the cabin air filter 10 is installed in the HVAC device, the filter passenger compartment air 10 is introduced and maintained in a direction orthogonal to gravity. In this case, one of its faces faces the bottom 131 of the housing 13. It is at a distance from the bottom 131.

o Mass sensor 11 Said at least one mass sensor 1 1 is configured for:

 - measure a weight p1 of the cabin air filter 10 during use (function illustrated in Figure 1 MEAS (p1));

 In a nonlimiting example, the weight p1 is measured every 1000 kilometers.

 Thus, the cabin air filter 10 is measured during use, namely when it is in use and therefore when it has already accumulated particles.

 In a nonlimiting embodiment, the measurement of said weight p1 is carried out when said heating, ventilation and / or air conditioning device 1 is switched off.

 In a first nonlimiting embodiment illustrated in FIG. 3, said at least one mass sensor 11 measures only the weight p1 of the cabin air filter 10 during use. The initial weight pO was initially loaded into the memory of the clogging detection device 3 described below, namely before the installation of the cabin air filter 10 in the housing 13 of the HVAC device, whether for pre-sales or after-sales of the motor vehicle 2.

 In a second nonlimiting embodiment illustrated in FIG. 4, said at least one mass sensor 11 is further configured to measure the initial weight pO of said cabin air filter 10. In this case, the initial weight pO was not initially loaded in the memory of the clogging detection device 3. For this purpose, the initiation of the measurement of the initial weight pO is carried out when the cabin air filter 10 is inserted in the housing 13 and comes to rest on said at least mass sensor 1 1.

 In a non-limiting embodiment, said at least mass sensor 1 1 is fixed to the bottom 131 of the housing 13 of the HVAC device. It is screwed or glued or clipped in non-limiting examples.

In a first nonlimiting embodiment illustrated in FIG. 5, the HVAC device comprises two mass sensors 11. This is advantageous when the cabin air filter 10 is arranged vertically. A side of the cabin air filter 10 rests while the two mass sensors 11 which are sufficient for the cabin air filter 10 to remain stable. It always remains in contact with the two mass sensors 1 1.

 In a second nonlimiting embodiment illustrated in FIG. 6, the HVAC device comprises three mass sensors 1 1. This makes it possible to have an isostatic support. This is advantageous when the cabin air filter 10 is arranged horizontally. One side of the cabin air filter 10 rests while the three mass sensors 11 which allow the cabin air filter 10 to remain stable, unlike a hypostatic solution with two mass sensors 1 1 only. It always remains in contact with the three mass sensors 1 1.

 After having carried out the measurement of the weight p1 and if necessary the measurement of the initial weight pO, said at least one mass sensor 11 communicates them to the clogging detection device 3.

 Thus, said at least one mass sensor 1 1 is configured to transmit said weight p1 (namely its measurement) to the clogging detection device 3 of said motor vehicle 2 (function illustrated in FIGS. 1 and 2 TX (p1)) from so that the latter calculates a weight difference ®P from said weight p1 and initial weight pO and compares it with at least one reference weight value Ready.

 It will be noted that, in a manner known to a person skilled in the art, a mass sensor 11 can perform a measurement to the nearest 0.1 g.

 In a nonlimiting embodiment, said at least one mass sensor 1 1 is further configured to transmit said initial weight pO to the clogging detection device 3 of said motor vehicle 2 (function illustrated in FIG. 2 TX (p0)) .

 In a nonlimiting embodiment, the transmission can for example be made by the communication protocol defined according to the vehicle.

 The clogging detection device 3 is described below.

• Clogging detection device 3 In a nonlimiting embodiment, said clogging detection device 3 corresponds to an electronic unit of said motor vehicle 2. In a nonlimiting alternative embodiment, said electronic unit is the central electronic unit, otherwise called ECU, of the motor vehicle 2 This central electronic unit is not part of the HVAC device.

In a nonlimiting variant, said electronic unit is an independent electronic unit capable of communicating with the central electronic unit via Bluetooth or other electronic means.

 The clogging capacity of the cabin air filter 10 is a function of the increase in weight of the cabin air filter 10. In fact, the more particles accumulated by the filter medium 100 of the cabin air filter 10, the more its weight increases. It will be recalled that the clogging capacity is the quantity in grams of particles that the filtering medium 100 can stop up to a certain acceptable pressure drop value Pa (a too high pressure drop Pa results in an insufficient air flow F in the passenger compartment 21 of the motor vehicle 2). The increase in weight is therefore a significant parameter for determining the life of the cabin air filter 100.

 Thus, the clogging detection device 3 is configured to:

 - receive from at least one mass sensor 11 a weight p1 of the cabin air filter 10 during use (function illustrated in Figures 1 and

2 RX (p1));

 - calculate a weight difference DR from said weight p1 and the initial weight pO of the cabin air filter 10 (function illustrated in FIGS. 1 and 2 MEAS (AP, pO, p1)).

The clogging detection device 3 calculates the difference in weight DR due to the accumulation of particles in the cabin air filter 1 1 by making the difference between the weight p1 measured during use of the air filter cockpit 10 and its initial weight pO.

In a nonlimiting embodiment, the calculation of the difference in weight DR is carried out approximately every 1000 kilometers traveled by the motor vehicle 2. Said clogging detection device 3 is further configured to:

- compare said weight difference DR with the reference weight value Ready (function illustrated in Figures 1 and 2 COM P (AP, Pref)).

Said clogging detection device 3 is provided with a ready reference weight value in memory corresponding to zero air flow, namely when the fan of the HVAC device is switched off. More particularly, the clogging detection device 3 includes in memory at least one clogging curve Cb, each clogging curve Cb being defined by an operating point or a plurality of operating points. The clogging curve Cb illustrated in FIG. 7 illustrates a characteristic point E which corresponds to the limiting clogging capacity of the cabin air filter 10 at zero air flow. This characteristic point E comprises on the ordinate a limit reference pressure drop Paret (in Pascal) and on the abscissa a reference weight Ready in grams which corresponds to a limit quantity Qp of particles.

 The ready reference weight value is the weight threshold from which it must be considered that the cabin filter 10 (in particular its filter medium 100) is obstructed, in other words clogged. Thus, the reference weight value Ready is characteristic of the end of life of said cabin air filter 10.

Thus, in a nonlimiting example, between the start and the end of the life of the cabin air filter 10, the weight of the latter increases from 10 g to 30 g, ie between 5% and 15% of its initial weight. Thus, if the ready reference weight value is 30g, when its weight increases by 10g, we know that the cabin air filter 10 has a wear percentage of 33%. Note that in a non-limiting embodiment, the weight of a cabin air filter 10 of an HVAC device is between 50g and 500g.

This clogging curve Cb thus serves as an abacus for the calculated weight difference DR. In the nonlimiting example illustrated in FIG. 7, there is a ready reference weight value of 25 grams for a zero air flow. Note that the clogging curve Cb is a function of the cabin air filter 10. Also, it may be different from a cabin air filter 10 to another.

 The comparison between the weight difference DR and the reference weight value Ready consists in seeing whether said pressure drop Pa is greater than or equal to the reference weight value Ready.

 If so, this means that the difference in weight DR caused by the cabin filter 10 is too great and as a result that its filter medium 100 is obstructed.

 Thus, if said weight difference DR is greater than or equal to said at least one reference weight value Ready, in a nonlimiting embodiment, the clogging detection device 3 generates an alarm I (function illustrated in FIGS. 1 and 2 ACTIV (I)). The generation of the alarm I is expressed by textual or graphic or light information displayed on the HMI man-machine interface of the motor vehicle 2 intended for the user of the motor vehicle 2. In nonlimiting examples, the information indicates to the user that it is necessary to change his cabin air filter 10 or that the latter is clogged. One can indicate for example the percentage of clogging. The user thus knows that his cabin air filter 10 must be changed.

Thus, the clogging (fouling) of the cabin air filter 10 of the HVAC device is detected according to the clogging detection method PR of a cabin air filter 10 of the HVAC device illustrated in FIG. 8, according to a mode non-limiting implementation. In this nonlimiting embodiment:

 - the clogging detection device 3 is independent of the HVAC device;

 - the initial weight pO was initially loaded into the clogging detection device 3.

 The clogging detection method PR includes:

- The measurement by at least one mass sensor 11 of a weight p1 of the cabin air filter 10 in use (step 1 illustrated); - Calculation by a clogging detection device 3 of a weight difference DR from said weight p1 and an initial weight pO of the cabin air filter 10 (step 3 illustrated);

 the comparison by said clogging detection device 3 of said weight difference DR with a reference weight value Ready (step

4 illustrated).

 In a nonlimiting embodiment, said clogging detection method PR further comprises the transmission by said at least one mass sensor 11 of said weight p1 (namely its measurement) to the clogging detection device 3 of said air filter of passenger compartment 10 which receives it (steps 2/2 'illustrated).

 In a nonlimiting embodiment, if said weight difference DR is greater than or equal to said reference weight value Ready, said clogging detection method PR further comprises the generation of an alarm I (step 5 illustrated).

Of course, the description of the invention is not limited to the embodiments described above.

 Thus, the invention applies to any type of cabin air filter 10, whether it be particles, activated carbon or anti-allergen. Note that an activated carbon cabin air filter is generally heavier than a particulate filter.

Thus, in another nonlimiting embodiment, the clogging detection device 3 is an electronic unit other than the central electronic unit, which is part of the HVAC device.

 Thus, in another nonlimiting embodiment, the clogging detection device 3 is part of said at least one mass sensor 11.

In this case, there is no transmission of the weight p1 and, where appropriate, of the initial weight pO.

Thus, in another nonlimiting embodiment, the HVAC device comprises four mass sensors 1 1 which makes it possible to have hyperstatic support. Thus, the invention described has in particular the following advantages:

- it avoids increasing the power of the fan of said HVAC device to ensure a constant air flow which makes it possible to increase the air flow in the cabin air filter 1 if the latter is clogged. It therefore avoids overconsumption of energy and premature wear of the fan of the HVAC device;

 - It allows the user to know precisely when to change the cabin air filter 10. Thus, he no longer changes his cabin air filter 10 after it is already too clogged. Thus, it no longer changes its cabin air filter 10 before it is clogged, while it can still perform its filtering functions.

 - it allows always to have well-filtered air in the passenger compartment 21 of the motor vehicle 2 and thus avoids having polluted air.

Claims

1. A heating, ventilation and / or air conditioning device (1) for a motor vehicle (2), according to which said heating, ventilation and / or air conditioning device (1) comprises:  - a cabin air filter (10);  - at least one mass sensor (11) configured for:  - measure a weight (p1) of said cabin air filter (10) during use;  - transmitting said weight (p1) to a clogging detection device (3) so that the latter can calculate a weight difference (DR) from said weight (p1) and from an initial weight (pO) of said filter passenger compartment air (10) and compare it with a reference weight value (Ready). 2. A heating, ventilation and / or air conditioning device (1) according to claim 1, according to which said reference weight value (Ready) is characteristic of an end of life of said cabin air filter (10). 3. A heating, ventilation and / or air conditioning device (1) according to claim 1 or claim 2, wherein said heating, ventilation and / or air conditioning device (1) comprises two or three mass sensors (1 1). 4. Heating, ventilation and / or air conditioning device (1) according to any one of claims 1 to 3, according to which the measurement of said weight (p1) takes place when said heating, ventilation and / or air conditioning device (1 ) is off. 5. A heating, ventilation and / or air conditioning device (1) according to any one of claims 1 to 4, according to which said at least a mass sensor (1 1) is further configured to measure said initial weight (pO) of said cabin air filter (10). 6. Clogging detection device (3) of a cabin air filter (10) of a heating, ventilation and / or air conditioning device (1) for a motor vehicle (2) according to one of claims 1 to 5, according to which said clogging detection device (3) is configured to:  - receive from at least one mass sensor (1 1) a weight (p1) of said cabin air filter (10) during use; - calculate a weight difference (DR) from said weight (p1) and an initial weight (pO) of said cabin air filter (10);  - compare said weight difference (DR) with a reference weight value (Ready). The clogging detection device (3) according to claim 6, wherein said clogging detection device (3) is further configured to generate an alarm (I) if said weight difference (DR) is greater than or equal to said reference weight value (Ready). 8. A clogging detection device (3) according to claim 6 or claim 7, wherein said initial weight (pO) of said cabin air filter (10) is loaded into memory in said clogging detection device (3 ). 9. Clogging detection method (PR) of a cabin air filter (10) of a heating, ventilation and / or air conditioning device (1) for a motor vehicle (2) according to one of claims 1 to 5, according to which said clogging detection method (PR) comprises the following steps: - Measurement by at least one mass sensor (1 1) of a weight (p1) of said cabin air filter (10) in use; - Calculation by a clogging detection device (3) according to one of claims 6 to 8, of a weight difference (DR) from said weight (p1) and an initial weight (pO) of said filter cabin air (10); - Comparison by said clogging detection device (3) of said weight difference (DR) with a reference weight value (Ready). 10. Clogging detection method (PR) according to claim 9, according to which, if said weight difference (DR) is greater than or equal to said reference weight value (Ready), said clogging detection method (PR) further includes the generation of an alarm (I).