The present invention relates to an air flow temperature and humidity sensor device, for use in combination with the passenger compartment air conditioning system of a motor vehicle.

There is a known air flow sensor device of this type which is inserted for use into an opening or passage provided in a confining panel of the passenger compartment of a motor vehicle.

In use, a miniature fan inside this sensor device is activated to draw from the passenger compartment of the motor vehicle a flow of air whose temperature and degree of humidity are determined. This miniature fan gives rise to vibrations which are transmitted to the panel of the passenger compartment of the motor vehicle to which the sensor device is connected. The vibrations transmitted to this panel create noise.

One object of the present invention is to provide an air flow temperature and humidity sensor device which enables the aforementioned drawback of the prior art devices to be overcome.

This and other objects are achieved according to the invention by means of an air flow temperature and humidity sensor device for insertion into an opening or passage provided in a confining panel of the passenger compartment of a motor vehicle, comprising:

a hollow supporting housing forming an inner region or chamber communicating with the exterior tlirough an inlet opening formed in an end portion of the housing, and a plurality of outlet openings formed in an intermediate portion of the housing,

an inner carrying structure mounted in the region or chamber of the supporting housing, and including a circuit board, which carries an electrical temperature sensor and an associated electrical humidity sensor adjacent to the inlet opening of the housing; a miniature electric fan adapted to create a flow of air from the passenger compartment through the opening or passage of the panel and the inlet and outlet openings of the supporting housing, while also including an impeller located in the proximity of the aforesaid outlet openings; an associated electric driving motor, preferably of the brushless type; and a multi-pole electrical connector, and wherein

the end portion of the supporting housing is provided with one or more resilient formations which can be inserted at least partially into the opening or passage in the panel, and which, when in use, can limit the transmission of vibrations from the supporting housing to the panel.

Preferably, the aforesaid resilient formation or formations are made of elastomeric material, and are overmoulded on the supporting housing.

Conveniently, the supporting housing comprises two half-shells coupled together, and the inlet opening of this housing is defined jointly by respective end portions of the two half- shells, each provided with one or more of the resilient vibration-damping formations. In an advantageous embodiment, the aforesaid end portion of the supporting housing has a first and a second resilient formation of substantially annular shape, spaced apart from each other longitudinally and interconnected by a plurality of essentially wedge-shaped formations, which are spaced apart angularly and which project outwards progressively from the inlet opening to the outlet openings of the supporting housing.

Further characteristics and advantages of the, invention will be made clear by the following detailed description, provided purely by way of non-limiting example, with reference to the attached drawings, in which:

Figure 1 is a perspective view of an air flow temperature and humidity sensor device according to the invention;

Figure 2 is a partially exploded perspective view of the sensor device of Figure 1 ;

Figure 3 is a partial perspective view which shows, on an enlarged scale, part of a half-shell of the sensor device according to the preceding figures; and

Figures 4 to 6 are perspective views which show the procedure for coupling a sensor device according to the invention to a confining panel of the passenger compartment of a motor vehicle. In the drawings, the number 1 indicates the whole of an air flow temperature and humidity sensor device according to the present invention.

As shown in Figures 4 to 6, and as described more fully below, the sensor device 1 is intended to be coupled to an opening or passage 50 (Figure 4) provided in a confining panel P of the passenger compartment of a motor vehicle, in order to draw from the passenger compartment a flow of air whose temperature and degree of humidity are to be determined. In the embodiment shown by way of example in the drawings, the sensor device 1 comprises a hollow supporting housing, indicated as a whole by 2, including two half- shells 2a and 2b, which form the upper and lower half-shells respectively, and which are coupled together. The upper half-shell 2a has a plurality of integral loop formations 3 which protrude downwards and are snap-fastened to corresponding retaining projections 4 provided on the lower half-shell 2b.

As shown in Figures 2 and 3, the upper edge of the half-shell 2b has a plurality of upwardly projecting studs 5, which engage in corresponding recessed seats 6, provided near the lower edge of the half-shell 2a, only one of these seats being shown, in broken lines, in Figures 1 and 2.

In the supporting housing 2 there is formed an inner region or chamber 7 (Figures 2 and 3) which communicates with the exterior through an inlet opening 8 formed in a front end portion 2c of the housing 2. and also through a ring of outlet openings 9 formed in an intermediate portion 2d of the housing 2.

In the inner region or chamber 7 of the housing 2 there is mounted a carrying structure indicated as a whole by 10 in Figure 2. This structure comprises, in particular, a circuit board 1 1 , for example a printed circuit board, which carries, adjacent to the inlet opening 8 of the housing 2, an electrical temperature sensor 12 and an electrical humidity sensor 13.

In the illustrated embodiment, the humidity sensor 13 is substantially cylindrical in shape, and is connected at its base to the board 1 1 , while the temperature sensor 12 extends above the humidity sensor 13.

A miniature electric fan, indicated as a whole by 14 in Figure 2, is also connected to the circuit board 1 1. This miniature fan comprises an impeller 15, having a plurality of radial blades 16, connected to a disc 17. The blades 16 of the impeller 15 extend into the proximity of the outlet openings 9 of the supporting housing 2, as can be seen in Figure 1.

The miniature fan 14 further comprises an electric motor 18, preferably of the brushless type, on the shaft 18a of which the impeller 15 is fixed (Figure 2).

The circuit board 1 1 also carries a plurality of electrical and/or electronic components of circuits associated with the sensors 12, 13 and with the electric motor 18, together with a multi-pole electrical connector 19 (Figures 1 and 2) conveniently located in the end portion 2e of the housing opposite to the front inlet portion 2c.

The electric motor 18 for driving the miniature fan 14 is fixed to a supporting plate 20 of resilient material, which is clamped between the two half-shells of the supporting housing 2. The resilience of this supporting plate helps to damp the vibrations caused by the motor in use.

With reference to "Figures 4 to 5, the front inlet portion 2c of the supporting housing is intended to be coupled to a tubular positioning and retaining formation 51 provided on the rear face of the panel P of the motor vehicle, around the aforementioned opening 50.

In the illustrated embodiment, the edge of the tubular formation 51 facing the sensor device 1 has a plurality of angularly spaced indentations 52.

The front end portion 2c of the housing of the sensor 1 is provided with a set of resilient formations adapted to be inserted at least partially into the tubular formation 51 , and if necessary into the indentations 52 of the edge of the latter, to limit the transmission of vibrations from this housing 2 to the panel P during use. These resilient formations, one embodiment of which is described in detail below, are conveniently made of a resilient material, and are overmoulded on the supporting housing 2.

With particular reference to Figure 1 , the end portion 2c of the supporting housing 2 is provided, in particular, with a first and a second resilient formation of substantially annular shape, indicated by 21 and 22, which are coaxial with the opening 8 and are spaced apart from each other longitudinally. These annular resilient formations 21 and 22 are interconnected by a plurality of essentially wedge-shaped formations 23 which are integral with the former and are spaced apart from each other angularly.

With particular reference to Figures 2 and 3, since the inlet opening 8 of the supporting housing 2 is formed jointly by respective end portions of the two half-shells 2a and 2b, in practice the resilient formations 21 , 22 and 23 are formed partially on the half-shell 2a, and partially in the lower half-shell 2b.

The formations.23 project outwards progressively, in the direction from the inlet opening 8 towards the intermediate openings 9 of the supporting housing 2.

With further reference to Figures 4 to 6, the front end 2c of the housing 2 of the sensor 1 is force-fitted into the tubular formation 51. The end 2c of the housing 2 of the sensor 1 is thus inserted with resilient interference into the tubular formation 51 of the panel P. Because of this distinctive coupling procedure, the transmission of vibrations from the housing 2 of the sensor device 1 to the panel P of the passenger compartment of the motor vehicle can be limited to a very great extent.

Clearly, provided that the principle of the invention is retained, the forms of application and the details of construction can be varied widely from what has been described and illustrated purely by way of non-limiting example, without thereby departing from the scope of the invention as defined in the attached claims.