FR3067291A1 - SENSOR FOR DETECTING PARTICULATE MATTER FOR MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a particulate matter detection sensor (10) for a motor vehicle comprising at least a first orifice defining a first air inlet (12) for a so-called external air flow and a second orifice defining a second air inlet ( 14) for said recirculating air flow, said air inlet (12) for the outside air flow and inlet (14) for the recycling air stream being distinct from each other. Application to the automotive field

Description

The invention relates to a particulate matter detection sensor for a motor vehicle.

It is known from document CN203221853 to equip a motor vehicle with a particulate matter detection sensor. Such a sensor is generally placed in the passenger compartment of the motor vehicle.

The term “particulate matter” means any particle of sufficiently small size, in general of size smaller than sizes of 10 μm in diameter, to be transported by air and to be inhaled.

The aforementioned document proposes a particulate matter detection sensor comprising two conduits making it possible to respectively sample an air flow coming from the exterior of a motor vehicle as well as an air flow coming from the passenger compartment of this same vehicle. automobile. One end of each of these two pipes is placed in communication with a solenoid valve which will determine the choice of air for which the particulate measurement must be carried out in the particulate matter sensor.

However, such a system is cumbersome and is not optimal in terms of cost.

The invention aims to improve the situation.

To this end, the present invention provides a particulate matter detection sensor for a motor vehicle comprising at least a first orifice defining a first so-called air inlet for a so-called external air flow and a second orifice defining a second air inlet. said air for a recirculating air flow, said air inlet for the outside air flow and inlet for the recirculating air flow being distinct from each other.

Embodiments propose that:

said particulate matter sensor comprises a first so-called main unit and a second unit said additional unit, said additional unit comprising said air inlet for the outside air flow and said inlet for the recirculating air flow,

- Said main unit includes a passage orifice defining an inlet of a fluid path for the air flowing in the main unit, the passage orifice being able to be placed in fluid communication with said air inlet for the flow of outside air and / or said inlet for the recirculation air flow of said additional unit,

- said air inlet for the outside air flow and / or said inlet for the recycling air stream are offset relative to said orifice for passage of said main unit,

said air inlet for the outside air flow and said inlet for the recirculating air stream are separated by at least one partition, said partition making it possible to define two channels called respectively channel for the outside air stream and recirculation air channel,

- said channel for the outside air flow comprises at least one baffle,

- the additional unit includes a first distribution means capable of distributing the air flow coming from the channel for the outside air flow or from the channel for the recirculation air flow at the level of a common chamber into which a end of the channels for the outside air flow and for the recycling air flow, in particular a distribution flap,

the additional unit has a third orifice for the injection of an air flow at the outlet of said particulate matter sensor into the additional unit,

- the additional unit includes a reinjection chamber,

- the re-injection chamber has an opening arranged near the air inlet for the outside air flow and the inlet for the recirculating air flow,

a second distribution means is provided for directing said flow of air leaving the particulate matter sensor from the reinjection chamber towards the channel for the outside air flow or the channel for the recirculation air flow from the housing additional,

- said additional unit comprises a partition facing the opening of the reinjection chamber,

- the second distribution means is provided at the level of the partition facing the opening of the reinjection chamber

- A micromotor is provided to actuate the first and / or the second distribution means.

- The additional unit comprises sealing means cooperating with the first or second distribution means so as to completely block the channel for the outside air flow or channel for the recycling air flow.

The invention also relates to a heating, ventilation and / or air conditioning device for a motor vehicle comprising or on which a particulate matter sensor as described above is disposed.

Other characteristics and advantages of the invention will emerge on reading the description which follows, with reference to the appended figures, which illustrate:

FIG. 1 illustrates a perspective view of a particulate matter detection sensor according to a first embodiment, FIG. 2 illustrates a perspective view of a particulate matter detection sensor of FIG. 1 without the cover of the additional box, Figure 3 illustrates a perspective view of a particulate matter detection sensor according to a second embodiment, Figure 4 illustrates a perspective view of the particulate matter detection sensor of Figure 3 without the cover of the additional box.

The particulate matter detection sensor 10 according to the present invention is suitable for use in a motor vehicle. This particulate matter detection sensor 10 comprises at least a first orifice defining a first air inlet 12 called for an air flow said outside and a second orifice defining a second air inlet 14 said for an air flow says recycling.

A flow of recycling air is understood to mean both an air flow taken from the living space and / or an air flow taken from a channel for circulating an air said to recycle an appliance. heating, ventilation and / or air conditioning for a motor vehicle.

According to the invention, the air inlet 12 for the outside air flow and the inlet 14 for the recirculating air flow are separate from each other.

In the embodiments illustrated here, the particulate matter sensor 10 comprises a first housing 16 called the main housing and a second housing 18 known as the additional housing.

The main box 16 main has at least one inlet or passage opening 20, an outlet 80 (visible in Figure 4), a particulate matter measurement chamber (not shown).

The passage orifice 20 defines an inlet of a fluid path for the air flowing in the main unit 16. This passage orifice 20 is capable of being placed in fluid communication with the air inlet 12 for the flow of outside air and / or inlet 14 for the recirculation air flow from the additional box 18.

Here, the main unit 16 is composed of two half-shells 60 and 62 connected together by screws (not shown) and / or clips 64.

The additional unit 18, meanwhile, has the air inlet 12 for the outside air flow and the inlet 14 for the recirculating air flow.

In the embodiments presented here, the air inlet 12 for the outside air flow and the air inlet 14 for the recirculating air flow are separated by at least one partition 22.

The partition 22 makes it possible to define two channels called channel 26 respectively for the flow of outside air and channel 28 for the flow of recycling air, a first end of which is defined, respectively, by the air inlet 12 for the outside air flow and the inlet 14 for the recycling air flow.

The channel 26 for the outside air flow and the channel 28 for the recirculating air flow both open, at the other end of the latter, into a common chamber 30 arranged at the end opposite the inlet. 12 for the outside air flow and at the inlet 14 for the recirculating air flow. The common room 30 communicates with the passage orifice 20 of the main box 16.

It will be noted that, in the embodiments illustrated here, the common chamber 30 has two bulges towards the interior of the latter. These two bulges making it possible to accommodate two screws for fixing the additional box 18 to the main box 16 without penalizing the size of the additional box 18.

According to a particular embodiment, the air inlet 12 for the outside air flow and / or the inlet 14 for the recirculation air flow are offset relative to the passage orifice 20 of the main unit 16. In other words, the air inlet 12 for the outside air flow and / or the inlet 14 for the recirculation air stream are spaced from the passage orifice 20.

Such an arrangement optimizes in particular the homogenization and stabilization of the speed of the air flow circulating in the channels and limits the impact on the impaction function of the particulate matter detection sensor 10.

In the embodiment illustrated in FIG. 1, the air inlet 12 for the outside air flow and the inlet 14 for the recirculating air flow are offset from one another.

An embodiment not described proposes that the inlet 14 for the recirculation air flow be placed near the passage orifice 20 of the main unit 16.

Here, the channel 26 for the outside air flow comprises at least one baffle 32. In other words, at least one baffle 32 is arranged in the channel 26 for the outside air flow. Such a baffle 82 makes it possible to create a balance of pressures between the air inlet 12 for the outside air flow and the air inlet 14 for the recirculating air stream thus leading to obtaining a constant air flow in the particulate matter detection sensor 10 at the main unit 16, and in particular at the level of the fluid path for the air circulating in the main unit 16 and in which the particulate measurement is carried out. In the particular embodiment illustrated in FIGS. 1 and 2, the channel 26 for the outside air flow comprises five baffles 32 arranged perpendicular to the partition 22.

It will be noted that the channel 26 for the outside air flow and the channel 28 for the recycling air flow of the first embodiment are of substantially identical length and width.

In an embodiment not described, the channel 26 for the external air flow and the channel 28 for the recirculation air flow have a width substantially identical to that of the fluid path for the air circulating in the main unit 16 and in which the particulate measurement takes place.

The additional box 18 here comprises at least two parts 66 and 68. The part 66 is substantially planar and forms a cover for the part 68. The cover 66 of the mode of the first embodiment is shown here in transparency. The cover 66 comprises, in this embodiment, the air inlet 12 for the outside air flow and the inlet 14 for the recirculating air flow.

The additional box 16 also includes a first distribution means 34 capable of distributing the air flow coming from the channel 26 for the outside air flow or from the channel 28 for the recycling air flow 28.

In this embodiment, the first distribution means 34 is disposed at the level of the common chamber 30 in which the distal end of the air inlets of the channels 26 for the outside air flow and 28 for the air flow recycling. The first distribution means 34 may in particular be a distribution flap.

A particular embodiment proposes that the first distribution means 34 make it possible to alternate the measurement of particulate matter between the flow of outside air and the flow of recirculating air.

In the embodiments presented here, the axis of the first distribution means 34 is arranged at the partition wall 22 and, in particular here, at its end adjoining the common chamber 30.

The additional box 18 further comprises, here, sealing means cooperating with the distribution means 34 so as to completely block the channel 26 for the outside air flow or the channel 28 for the recirculating air flow. In the embodiments illustrated here, the sealing means are partitions 26 arranged obliquely relative to the partition 22.

The part 68 cooperating with the cover 66 receives, for its part and in this embodiment, the partition 22, the baffles 32 and the first distribution means 34.

In the embodiments illustrated in the present application, the additional box 18 is distinct from the main box 16.

The main housing 16 and the additional housing 18 are secured to each other. This securing may, for example, be achieved by means of screws and / or clips. An embodiment not shown proposes that the additional box 18 be molded onto the main box 16.

An embodiment not shown proposes that a seal be disposed at least on the periphery of the additional housing 18 and interposed between the faces of the additional housing 18 and the main housing 16 in contact with each other.

It will be noted that in the embodiment illustrated in FIGS. 1 and 2, the width of the additional box 18 is substantially identical to that of the main box 16.

A second embodiment illustrated in FIGS. 3 and 4 proposes that the additional box 16 also has a third orifice 38 for injecting an air flow at the outlet of the particulate matter sensor 10 into the additional box 16. The third orifice 38 will be called reinjection orifice 38 in the remainder of this description.

Indeed, there is a pressure difference between the passage orifice 20 of the main housing 16 and the outlet 80 of the particulate matter sensor 10. This pressure difference can disturb the air flow at the level of the fluid path for the air flowing in the main housing 16 and thus leads to distorting the measurement of the particulate matter. The addition of the third reinjection orifice 38 makes it possible to limit this pressure difference.

Here too, the cover of the 66 of the additional box 18 is shown in transparency. In this embodiment, the air inlet 12 for the outside air flow and the inlet 14 for the recirculating air flow are all from an outside or indoor air supply pipe 84.

In the embodiment of FIG. 3, the outlet 80 of the main unit 16 and the reinjection orifice 38 are connected by means of a pipe 82.

Still in this embodiment, the additional box 16 also includes a re-injection chamber 40 into which the re-injection orifice 38 opens.

In the embodiment illustrated in FIGS. 3 and 4, the reinjection chamber 40 extends in parallel with the main axis of extension of the channel 26 for the flow of outside air and that of the channel 28 for the flow of recirculation air. In particular, the reinjection chamber 40 is interposed between these two channels 26 for the flow of outside air and 28 for the flow of recirculating air.

In this second embodiment, the air inlet 12 for the outside air flow and the air inlet 14 for the recirculation air flow are separated by the partition 22 and the reinjection chamber 40, the partition 22 allowing part of said reinjection chamber 40 to be defined.

As can be seen in FIG. 4, the reinjection chamber 40 has an opening 42 disposed near the air inlet 12 for the outside air flow and the inlet 14 for the recirculating air stream.

Here, a second distribution means 44 is provided for directing the flow of air leaving the particulate matter sensor 10 from the reinjection chamber 40 towards the channel 26 for the flow of outside air or the channel 28 for the flow of recycling air.

The additional unit 18 comprises, in this embodiment, a partition 46 facing the opening 42 of the reinjection chamber 40.

The second distribution means 44 is here provided at the partition 46 facing the opening 42 of the reinjection chamber 40. The second distribution means may be, for example, a distribution flap.

According to a variant of the invention common to the two embodiments illustrated here, a micromotor is provided for actuating at least one distribution means 34 or 44. This micromotor will, for example, be provided for actuating the distribution means 34 or 44 to regular and defined interval. This time interval will be linked to the time of passage of the air measured in the particulate matter sensor 10 and the precision desired for the measurement of this matter.

The particulate matter sensor 10 according to the present invention may, for example, be placed on or integrated in a heating, ventilation and / or air conditioning device for a motor vehicle. The expression heating, ventilation and / or air conditioning apparatus for a motor vehicle is understood to mean an apparatus capable of regulating the aerothermal parameters of a flow of air distributed to the interior of a passenger compartment of a motor vehicle. This heating, ventilation and / or air conditioning device for a motor vehicle generally comprises a housing delimited by walls and partitions in which openings are made.

Claims (10)

claims 1. Particulate matter detection sensor (10) for a motor vehicle comprising at least a first orifice defining a first air inlet (12) said for a so-called external air flow and a second orifice defining a second air inlet (14) called for a recirculating air flow, said air inlet (12) for the outside air flow and inlet (14) for the recirculating air flow being distinct from one of the other. 2. Particulate matter detection sensor (10) according to claim 1 wherein said particulate matter sensor (10) comprises a first housing (16) said main and a second housing (18) said additional housing, said additional housing (18 ) comprising said air inlet (12) for the outside air flow and said inlet (14) for the recirculation air stream. 3. Particulate matter detection sensor (10) according to claim 2 wherein the main housing (16) has a passage opening (20) defining an inlet of a fluid path for the air circulating in the main housing (16 ), the passage orifice (20) being able to be placed in fluid communication with said air inlet (12) for the outside air flow and / or said inlet (14) for the recirculating air stream of said additional box (18). 4. Particulate matter detection sensor (10) according to claim 3 wherein said air inlet (12) for the outside air flow and / or said inlet (14) for the recirculation air flow are offset relative to said passage orifice (20) of said main housing (16). 5. Particulate matter detection sensor (10) according to one of the preceding claims, in which said air inlet (12) for the outside air flow and said inlet (14) for the recirculation air stream are separated by at least one partition (22), said partition (22) making it possible to define two channels called channel (26) respectively for the outside air flow and channel (28) for the recirculation air flow . 6. Particulate matter detection sensor (10) according to the preceding claim wherein said channel for the outside air flow (26) comprises at least one baffle (32). 7. Particulate matter detection sensor (10) according to claim 5 or 6 in which there is provided a distribution means (34) adapted to distribute the air flow from the channel (26) for the external air flow or the channel (28) for the recirculation air flow at the level of a common chamber (30) into which one end of the channels opens for the external air flow (26) and for the recirculation air flow (28), in particular a distribution component. 8. Particulate matter sensor (10) according to one of claims 2 to 7 in which the additional box (16) has a third orifice (38) said reinjection orifice for the injection of an air flow at the outlet said particulate matter sensor (10) in the additional housing (16). 9. Particulate matter sensor (10) according to the preceding claim wherein the additional unit (16) further comprises a reinjection chamber (40) 10. Particulate matter sensor (10) according to the preceding claim wherein a second distribution means (44) is provided for directing said flow of air leaving the particulate matter sensor of the re-injection chamber (40) towards the channel (26) for the outside air flow or the channel (28) for the recirculating air flow.