Air-distribution device for motor vehicles

Described herein is an air-distribution device which uses means designed for causing deviation, by Coanda effect, of a flow of air coming from an inlet duct into a plurality of outlet ducts. The invention is applicable both to a motor-vehicle air-conditioning assembly, which incorporates a conveyor with a heating element, and to a motor-vehicle dashboard.

BACKGROUND OF THE INVENTION

The present invention relates to air-distribution devices for motor vehicles, of the type comprising a body with an inlet duct for inflow of air, a plurality of outlet ducts for outflow of air, and means designed for distributing the flow of air coming from the inlet duct into the various outlet ducts.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a device of the type referred to above that will present a simple, light structure, with small overall dimensions, and nevertheless characterized by efficient and reliable operation.

In order to achieve the above purposes, according to a first aspect, the subject of the invention is an air-distribution device for motor vehicles, comprising a body with an inlet duct for inflow of air, three outlet ducts for outflow of air and means of perturbation of the flow of air coming from said inlet duct, the said means having three different operating positions, which cause deviation, by Coanda effect, of the flow of air selectively into the first, second, or third outlet duct.

The Coanda effect has been known and studied for some time. As a result of this phenomenon, a flow coming from a duct that gives out into an enlarged chamber, which has two side walls set at different distances from the outlet mouth of the duct, tends to adhere to the wall that is closer to the outlet mouth.

In the preferred of embodiment of the invention, the inlet duct has a mouth giving out into a first chamber, which has a first side wall right up against the aforesaid mouth and a second side wall opposite to the first wall and at a greater distance from the mouth, said first outlet duct having a side wall set on the prolongation of said first side wall of the first chamber and said means of perturbation having a first operating position in which said means are deactivated, so that the flow of air coming from the inlet duct follows, by Coanda effect, the aforesaid first wall of the first chamber and the side wall of the first outlet duct set on its prolongation, so that the flow is sent into said first outlet duct.

Once again in the case of the aforesaid preferred embodiment, the means of perturbation have a second operating position, in which they define a projection on said first side wall of the first chamber in such a way as to detach the flow of air from said first wall and favour its deviation, by Coanda effect, into the aforesaid second outlet duct, which has a wall set substantially on the prolongation of said second wall of the first chamber.

Once again in the case of the aforesaid preferred embodiment, the aforesaid first chamber communicates with the first outlet duct by means of a second mouth that opens out into a second chamber, which has a wall that joins the first side wall of the first chamber with the aforesaid side wall of the first outlet duct, and a second side wall set further away from said second mouth, which prolongs in a side wall of the third outlet duct, said means of perturbation having a third operating position, in which they define a projection on said first side wall of said second chamber so as to detach the flow of air from said side wall and favour its deviation towards the second wall of the second chamber and consequently into said third outlet duct.

Once again in the case of the aforesaid preferred embodiment, the aforesaid means of perturbation preferably comprise a rocking member, which is mounted so that it oscillates on the body of the device and which has opposite end portions designed to project from respective slits of said first wall of said first chamber and of said first wall of said second chamber.

According to a further aspect of the invention, the aforesaid inlet duct receives the flow of air from a conveyor, in which one or more heating elements are interposed. Said characteristic is protected, according to the invention, also with reference to the case in which the distribution device envisages just two outlet ducts and there are envisaged deviator means, which may be means for creating perturbation or means designed for altering the geometry of the duct for passage of the air, said latter means being designed for causing deviation of the flow of air by Coanda effect.

Again according to a further aspect of the invention, it is possible to envisage a distribution device with two or more outlet ducts, which uses means for perturbation of the flow of air that have more than one operating position and are incorporated in a motor-vehicle dashboard, with the aim of distributing the air towards the air-outflow mouths provided on said dashboard.

DETAILED DESCRIPTION OF THE INVENTION

With reference toFIGS. 1-3, the reference number1designates, as a whole, a motor-vehicle air-conditioning assembly comprising a body2, in which there is defined an inlet duct3for a flow of air. The duct3gives out by means of a mouth3A into an enlarged chamber4, which has a first wall4A that is located right up against the mouth3A, and a second wall4B opposite thereto, which is located at a greater distance from the mouth3A. The chamber4gives out, by means of a second mouth4C, into a second chamber5.

The device comprises a first outlet duct6, a second outlet duct7, and a third outlet duct8. The chamber5has a first wall5A, which is right up against the mouth4A, and a second side wall5B, which is located at a greater distance from the mouth4B. As may moreover be seen in the drawings, the first outlet duct6has a side wall6A, which is set on the prolongation of the side wall5A of the second chamber5and of the side wall4A of the first chamber4. The latter in turn is set on the prolongation of a corresponding side wall of the inlet duct3. Said walls are set, one on the prolongation of the other, according to a curved pattern, as may be seen inFIGS. 1to3.

The device comprises an element for perturbation of the flow, consisting of a rocker member9, which is mounted so that it oscillates about an axis10on the body2of the device and which has end portions10A and10B (seeFIGS. 2 and 3) designed to project through respective slits made in the first side wall4A of the chamber4and in the first side wall5A of the chamber5, for reasons that will emerge clearly from what follows.

The perturbation member9is designed to assume three different operating positions, which are respectively illustrated inFIGS. 1,2and3for causing deviation of the flow coming from the inlet duct3in the first outlet duct6(FIG.1), or else in the second outlet duct7(FIG.2), or else in the third outlet duct8(FIG.3).

FIG. 1illustrates the perturbation member9in a first operating condition that corresponds to an intermediate position, in which neither of the two end portions10A,10B of the perturbation member9projects from the respective wall. In said condition, the flow tends to remain adherent to the curved wall defined by the wall4A, the wall5A, and the wall6A. This occurs by Coanda effect, in so far as the flow that gives out into the chamber4tends to remain adherent to the side wall closer to the outflow mouth3A, and the same occurs when the flow gives out through the mouth4A into the second chamber5.

Starting from the condition described above and illustrated inFIG. 1, the perturbation member9can be made to oscillate into one or into the other of the two end positions illustrated inFIGS. 2 and 3. In the case of the position illustrated inFIG. 2, the end portion10A projects from the first side wall4A of the chamber4so that it causes a detachment of the flow of air from the wall4A and a consequent attraction, again by Coanda effect, of the flow of air towards the second outlet duct7, with consequent formation of an area of negative pressure11in the part of the chamber4more adjacent to the wall4B.

FIG. 3illustrates the opposite situation, in which the end portion10B projects from the wall5A, causing detachment of the flow of air from said wall and its consequent attraction towards the outlet duct8, with consequent formation of an area of negative pressure12in the part of the chamber5more adjacent to the wall5B.

According to a further characteristic illustrated in the drawings, englobed in the body2of the device is a conveyor13, which contains heating elements14for heating the flow of air, as well as an evaporator15forming part of the air-conditioning system.

The provision of an air-conditioner assembly which incorporates both deviator means by Coanda effect and a heating element forms the subject of the present invention independently of the provision of the three outlet ducts described above and of the corresponding perturbation rocker member.

FIGS. 4 and 5illustrate an example of embodiment in which the air-conditioner assembly has a plurality of outlet ducts20, which branch off two by two from a common inlet duct21, which receives air by means of a conveyor22, associated to which is a fan assembly23. Inserted in the conveyor22is an evaporator24and a plurality of independent heating elements25, each of which controls a respective inlet duct21(FIG. 2illustrates just two of the four inlet ducts21). For each inlet duct21, the distribution of air in the two outlet ducts associated thereto is controlled by a fluid device26consisting of a roller-type open/close element designed to open or close a window27on one side of a chamber28, into which there gives out the inlet duct21and from which there branch off the two outlet ducts20. When the open/close element26is in the condition in which it keeps the window27closed, the flow coming from the inlet duct tends to remain adherent to the side wall of the chamber28that is closer to the mouth of the inlet duct21. When the window27is open, the side wall closer to the outlet of the duct21becomes the opposite wall, so that the flow is deviated into the second outlet duct. It should be noted that a roller-type fluid element of the kind described above has already been illustrated in the international patent application of the present application No., which was still secret at the date of filing of the present patent application.FIG. 4illustrates also the motor assembly30, which controls the angular position of the two roller-type open/close elements26, for example by means of a mechanism of the type illustrated in the aforesaid international patent application, which does not form a subject of the present invention.

Finally,FIGS. 6 and 7illustrate a third embodiment of the invention, which is applied in this case to the distribution of air to the outflow mouths arranged above a motor-vehicle dashboard. In said figures, the reference number40designates a motor-vehicle dashboard, illustrated in cross-sectional view, in a vertical plane parallel to the longitudinal direction of the motor vehicle. Inside the body of the dashboard there is obtained an inlet duct41for a flow of air, which gives out, by means of a mouth42, into a chamber43, from which there branch off a first outlet duct44that gives out on the top surface of the dashboard40, immediately underneath the windscreen45of the motor vehicle, and in a second outlet duct46that conducts the flow of air to aeration mouths47set on the front wall of the dashboard, facing the driver.

The chamber43, which gives out into an inlet duct41, has a side wall48immediately adjacent to the mouth42, in a side wall49opposite thereto, which is, instead, at a greater distance from the mouth41. Incorporated in the wall48is a fin48A that can be deflected, which can be displaced between the inoperative condition, illustrated inFIG. 6, in which it does not project inside the chamber43, and an operative condition, illustrated with a dashed line once again inFIG. 6, in which it does project into said chamber. In the first condition, the flow that comes from the duct41tends to remain adherent to the wall48closer thereto, so that it is deviated into the duct46. When the fin48A is, instead, in the operative condition, illustrated with a dashed line, it causes detachment of the flow from the wall48and its consequent attraction towards the opposite wall and inside the outlet duct44. The displacement of the fin48A between the two operating positions can be obtained in any way, for example by cam means (not illustrated).FIG. 7is substantially similar toFIG. 6, except for the different disposition of the fin48A, which in this case has its anchoring area facing the inlet duct41. With said disposition, it is also possible to envisage an analogical regulation, i.e., the possibility of regulating continuously the amount of air distributed into the two ducts, between a first extreme condition, in which the entire flow of air enters the duct46, and a second extreme condition, in which the entire flow of air enters the duct44. In this configuration, in fact, the jet tends to remain attached to the wall48, once again by Coanda effect.