Filtering device for intake air of an engine for a vehicle

Abstract

 Filtering device (9) for the air taken in by the engine (4) of a vehicle (1) which is housed inside the engine compartment (2) of said vehicle (1); the filtering device (9) comprises: an air-box (10) internally comprising at least one cavity (11) having at least one intake opening (12) towards the external environment and at least one outlet opening (13) towards a suction system (5) of the engine (4); and at least one filtering element (14) housed inside the air-box (10) and arranged between the intake opening (12) and the outlet opening (13); the air-box (10) having a flattened form which reproduces in plan view the horizontal section of the engine compartment (2), and being suitable to be located inside said engine compartment (2) above the engine (4), so that it constitutes an upper cover of the engine (4) and an upper closure of the engine compartment (2).

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a filtering device for the air taken in by the engine of a vehicle.

PRIOR ART

[0002] In the vehicles currently available on the market, the filtering device for the air taken in by the engine comprises an air-box which is typically of a parallelepiped shape and internally houses a filtering element; the filtering element divides the air-box into an intake chamber, which is arranged upstream of the filtering element and communicates with the external environment via an intake opening, and an outlet chamber, which is arranged downstream of the filtering element and communicates with the suction system of the engine via an outlet opening. The filtering element must have a clear passage large enough to ensure a sufficiently limited pressure drop (i.e. difference in pressure between the air upstream and downstream of the filtering device) in that the greater the drop in pressure due to the filtering device the greater the reduction in the maximum power that can be generated by the engine. Moreover, the volume of the outlet chamber must be big enough in order for it to act as a lung of the suction system, i.e. to store a sufficiently large amount of air to absorb any fluctuations in the amount of air that is taken in by the suction system.

[0003] From the above it is clear that the air-box must be rather large in size to prevent any reduction in engine performance; however, in the vehicles currently on the market there is increasingly little room available in the engine compartment to house the filter box. Consequently, in the engine compartment of the latest vehicles it is increasingly complicated to fit an air-box that is large enough not to reduce engine performance.

[0004] WO2007131497A1 and EP1308373A1 describe a filtering device for the air taken in by an engine of a vehicle housed in an engine compartment of said vehicle. The filtering device is provided with: an air-box internally comprising a cavity provided with an intake opening towards the external environment and an outlet opening towards a suction system of the engine, and a filtering element housed inside the air-box and arranged between the intake opening and the outlet opening; the air-box has a flattened form which reproduces in plan view the horizontal section of the engine compartment and is suitable to be arranged inside said engine compartment above the engine so as to form an upper cover of the engine and constitute an upper closing of the engine compartment.

DESCRIPTION OF THE INVENTION

[0005] The object of the present invention is to provide a filtering device for the air taken in by the engine of a vehicle, said filtering device overcoming the drawbacks described above and, at the same time, being easy and inexpensive to produce.

[0006] According to the present invention there is provided a filtering device for the air taken in by an engine of a vehicle as claimed in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention will now be described with reference to the accompanying drawings, illustrating some non-limiting embodiments thereof, in which:

• figure 1 is a schematic, perspective view with some parts removed for the sake of clarity of an engine compartment of a vehicle provided with a filtering device according to the present invention;
• figure 2 is a schematic plan view of the engine compartment of figure 1, with some parts removed for the sake of clarity;
• figure 3 is a schematic, horizontal cross-sectional view of the filtering device of figure 1, with some parts removed for the sake of clarity;
• figure 4 is a schematic, vertical cross-sectional view along the line IV-IV of the filtering device of figure 1, with some parts removed for the sake of clarity;
• figures 5, 6 and 7 are schematic cross-sectional views of the filtering device of figure 1, with some parts removed for the sake of clarity;
• figures 8 and 9 are two different schematic perspective views of an alternative embodiment of the filtering device of figure 1, with some parts removed for the sake of clarity;
• figure 10 is a schematic perspective view, with some parts removed for the sake of clarity, of an alternative embodiment of a filtering device according to the present invention coupled to an internal combustion engine;
• figure 11 is a schematic, horizontal cross-sectional view of the filtering device of figure 1, with some parts removed for the sake of clarity;
• figure 12 is a schematic, vertical cross-sectional view along the line XII-XII of the filtering device of figure 8, with some parts removed for the sake of clarity;
• figures 13 and 14 are two different schematic perspective views of an alternative embodiment of the filtering device of figure 10, with some parts removed for the sake of clarity; and
• figures 15 and 16 are two different schematic perspective views of an alternative embodiment of the filtering device of figure 1, with some parts removed for the sake of clarity.

PREFERRED EMBODIMENTS OF THE INVENTION

[0008] In the accompanying figures, designated as a whole by number 1 is a road vehicle 1 (in particular a car) comprising an engine compartment 2 arranged in a front position and closed at the top by a pivotally attached bonnet 3, and an internal combustion engine 4 (illustrated in figure 2) housed inside the engine compartment 2. As illustrated in figure 2, the engine 4 comprises a suction system 5 provided with an intake butterfly valve 6 that regulates the flow of fresh air into an intake manifold 7 that communicates with the cylinders (not illustrated) of the engine 4 via respective intake ducts 8.

[0009] As illustrated in figures 1 and 3, the engine 4 is provided with a filtering device 9 for the air taken in by the engine 4. The filtering device 9 comprises an air-box 10 internally comprising a cavity 11 having at least one intake opening 12 towards the external environment and at least one outlet opening 13 towards the suction system 5 of the engine 4; the filtering device 9 also comprises at least one filtering element 14 that is housed inside the air-box 10 and is arranged between the intake opening 12 and the outlet opening 13. The filtering element 9 divides the cavity 11 into an intake chamber, which is arranged upstream of the filtering element 14 and communicates with the external environment via the intake opening 12, and an outlet chamber, which is arranged downstream of the filtering element 14 and communicates with the suction system 5 of the engine 4 via the outlet opening 13.

[0010] As illustrated in figures 1, 3 and 4, the air-box 10 has a flattened form which reproduces in plan view the horizontal section of the engine compartment 2 and is suitable to be arranged inside said engine compartment 2 above the engine 4 so that it constitutes an upper cover of the engine 4 and an upper closure of the engine compartment 2. In other words, the vertical thickness of the air-box 10 in correspondence with the cavity 11 is much smaller than a horizontal extension; for example the vertical thickness of the air-box 10 in correspondence with the cavity 11 is in the region of some centimetres and is generally between 3 and 10 cm while the horizontal extension of the air-box 10 is in the region of some tens of centimetres on each side and the transverse width is between 80 and 150 cm and the longitudinal length is between 50 and 120 cm.

[0011] According to a preferred embodiment, the air-box 10 has a variable vertical thickness so that it can adapt to the vertical dimensions of the engine 4 and the air-box 10 thus has a vertical thickness that is lower at the centre and higher at the ends; in this way, the air-box 10 achieves a cavity 11 with a large volume while taking up a minimum amount of space inside the engine compartment 2.

[0012] The air-box 10 has a more or less parallelepiped form and comprises a horizontal upper wall 15, a horizontal lower wall 16 which is parallel and opposite to the upper wall 15, a vertical front wall 17, a vertical back wall 18 which is opposite to the front wall 17, and two vertical side walls 19 which are opposite to each other. According to a preferred embodiment illustrated in the accompanying figures, the intake opening 12 is arranged in proximity to the front wall 17 and preferably through the front wall 17 and the outlet opening 13 is arranged in proximity to the back wall 18 and preferably through the lower wall 16; in this way the outlet opening 13 can be arranged immediately above the butterfly valve 6 and the air-box 10 can thus discharge directly into the butterfly valve 6 without any need for connecting ducts.

[0013] According to a preferred embodiment, the intake opening 12 is suitable to receive the air from a dynamic air intake 20 obtained through a front wall 21 of the vehicle 1; in particular, the filtering device 9 comprises a tubular intake pipe 22, which is suitable to connect the intake opening 12 to the dynamic air intake 20 obtained through the front wall 21 of the vehicle 1. It is important to note that the intake opening 12 is very close to the dynamic air intake 20 so that, if necessary, the intake pipe 22 is very short and thus results in extremely reduced pressure drops. Thus, when the vehicle 1 is travelling the pressure of the air against the front wall 21 of the vehicle 1 generates an overpressure inside the cavity 11 which is greater the faster the vehicle 1 is travelling; this overpressure inside the cavity 11 results in increased filling of the cylinders of the engine 4 and thus increased power generated by said engine 4.

[0014] According to the embodiment illustrated in figures 3 and 4, the filtering element 14 is arranged in correspondence with the intake opening 12; in this embodiment the intake chamber is practically non-existent and the entire cavity 11 coincides with the outlet chamber. According to the embodiments illustrated in figures 5 and 6, the filtering element 14 is arranged inside the cavity 11 (closer to the intake opening 12 in the embodiment shown in figure 5, closer to the outlet opening 13 in the embodiment shown in figure 6); in this embodiment the cavity 11 contains both the intake chamber and the outlet chamber. According to the embodiment illustrated in figure 7, the filtering element 14 is arranged in correspondence with the outlet opening 13; in this embodiment the outlet chamber is practically non-existent and the entire cavity 11 coincides with the intake chamber (this configuration is not disadvantageous in that the intake chamber has a very large volume and is arranged immediately upstream of the filtering element 14 and thus capable of acting as a lung of the suction system 5).

[0015] Figures 8 and 9 illustrate a further alternative embodiment of the filtering device 9, in which the cavity 11 is provided with two intake openings 12 towards the external environment arranged side by side and a single outlet opening 13 towards the suction system 5 of the engine 4; the filtering element 14 is arranged inside the cavity 11 and in the vicinity of the outlet opening 13.

[0016] In the embodiment illustrated in figures 1 to 9, the cavity 11 of the air-box 10 substantially extends over the entire area of the air-box 10. Alternatively, according to the embodiment illustrated in figures 10 to 12, the cavity 11 of the air-box 10 only extends over a limited part of the air-box 10; in this embodiment, the remaining part 23 of the air-box 10, over which the cavity 11 does not extend, is internally solid and has a smaller vertical thickness (normally less than 1 cm) compared to the vertical thickness of the part of the air-box 10 over which the cavity 11 extends. In other words, the air-box 10 has some raised and internally hollow parts which define the cavity 11 and other lower and internally solid parts 23 which are arranged around the cavity 11 (i.e. the parts 23 are substantially flat).

[0017] According to the embodiment illustrated in figures 10 to 12, the cavity 11 comprises two main tubular portions 11a and 11b, each of which is provided with its own intake opening 12 separate and independent from the intake opening 12 of the other and is provided internally with its own filtering element 14 separate and independent from the filtering element 14 of the other. Moreover, the cavity 11 comprises a tubular connecting portion 11c that receives the air from both of the main tubular portions 11a and 11b and ends in correspondence with the outlet end 13; the tubular connecting portion 11c carries the air passing through the two main tubular portions 11a and 11b towards the outlet end 13.

[0018] In the embodiment illustrated in figures 10 to 12, the two main tubular portions 11a and 11b are parallel to one another; alternatively, the two main tubular portions 11a and 11b could be arranged in a V-shape and converge towards one another in correspondence with the tubular connecting portion 11c.

[0019] In the alternative embodiment illustrated in figures 13 and 14, the tubular connecting portion 11c is shaped differently with respect to that illustrated in figures 10 to 12 and the outlet opening 13 is arranged at the centre of the tubular connecting portion 11c.

[0020] In the alternative embodiment illustrated in figures 15 and 16, instead of arranging two filtering elements 14 in the two main tubular portions 11a and 11b, a single filtering element 14 is arranged in the tubular connecting portion 11c.

[0021] According to a further alternative embodiment that is not illustrated, the cavity 11 comprises a single tubular portion that extends from the intake opening 12 to the outlet opening 13; in other words, in this embodiment the cavity 11 is tubular in shape and extends from the intake opening 12 to the outlet opening 13.

[0022] Numerous advantages are achieved with the filtering device 9 described above, as it is easy and inexpensive to produce and above all has an air-box 10 with a very large volume (thus suitable to house a filtering element 14 with a large clear passage) while taking up very little or even no space in the engine compartment 2. This result is achieved thanks to the fact that the air-box 10 is flat (i.e. "board"-shaped) so that it can be arranged above the engine 4 to constitute an upper cover for the engine and to constitute an upper closure of the engine compartment 2; in other words, the air-box 10 is shaped so as to occupy the space within the engine compartment 2 that is normally free (i.e. not used by any other devices) and thus does not actually take up any space inside the engine compartment 2.

[0023] Moreover, the air-box 10 performs two functions: it guarantees the supply of fresh air to the engine 4 and constitutes an upper closure of the engine compartment 2. The latter function is not secondary or useless; on the contrary, it is important in that the current tendency is to build an aesthetically "ugly" engine 4 in order to cut costs (i.e. without having to consider the appearance of the engine and thus avoiding the use of expensive materials, not having to hide electric wiring and hydraulic/pneumatic hoses or to choose less rational but more "attractive" layouts) and at the same time to provide the engine compartment 2 with a cover screen having a suitably finished upper surface (in the present invention the air-box 10 acts as the cover screen).

[0024] Lastly, it is important to note that the function of acting as an upper closure of the engine compartment 2 is not only an advantage in terms of appearance, but is also useful for reducing the noise emissions of the engine 4 as it constitutes a valid acoustic screen (for that purpose the engine-box 10 can be further soundproofed by applying sound-absorbing materials).

Claims

1. Filtering device (9) for the air taken in by the engine (4) of a vehicle (1) which is housed inside the engine compartment (2) of the vehicle (1); the filtering device (9) comprises:

an air-box (10) internally comprising at least one cavity (11) which is provided with at least one intake opening (12) towards the external environment and at least one outlet opening (13) towards a suction system (5) of the engine (4), having a flattened form which reproduces in plan view the horizontal section of the engine compartment (2), and suitable to be located inside the engine compartment (2) above the engine (4), so that it constitutes an upper cover of the engine (4) and an upper closure of the engine compartment (2); and

at least one filtering element (14) which is housed inside the air-box (10) and is placed between the intake opening (12) and the outlet opening (13);

wherein the cavity (11) extends over a limited part of the air-box (10) and the remaining part of the air-box (10), over which the cavity (11) does not extend, has a vertical thickness which is lower than the vertical thickness of the part of the air-box (10) over which the cavity (11) extends; and

wherein the cavity (11) has a tubular shape and extends from the intake opening (12) to the outlet opening (13) ;

the filtering device (9) is characterised in that the cavity (11) comprises at least two main tubular portions (11a, 11b), each of which is provided with its own intake opening (12), which is separate and independent from the intake opening (12) of the other portion.

2. Filtering device (9) according to claim 1, wherein each main tubular portion (11a; 11b) is provided internally with its own filtering element (14), which is separate and independent from the filtering element (14) of the other main tubular portion (11b; 11a).

3. Filtering device (9) according to claim 2, wherein the cavity (11) comprises a tubular connection portion (11c) which receives air from both the main tubular portions (11a, 11b) downstream from the filtering elements (14) and ends in correspondence with the outlet opening (13).

4. Filtering device (9) according to claim 1, wherein the cavity (11) comprises a tubular connection portion (11c) which receives air from both the main tubular portions (11a, 11b), ends in correspondence with the outlet opening (13), and houses a sole common filtering element (14).

5. Filtering device (9) according to claim 3 or 4, wherein the outlet opening (13) is located above a butterfly valve (6) of the suction system (5).

6. Filtering device (9) according to one of the claims from 1 to 5, wherein the remaining part of the air-box (10), over which the cavity (11) does not extend, is internally solid.

7. Filtering device (9) according to one of the claims from 1 to 6, wherein the air-box (10) has a more or less parallelepiped form and comprises a horizontal upper wall (15), a horizontal lower wall (16) which is parallel and opposite to the upper wall (15), a vertical front wall (17), a vertical back wall (18) which is opposite to the front wall (17), and two vertical side walls (19) which are opposite to each other; the intake opening (12) is located through the front wall (17) and the outlet opening (13) is located through the lower wall (16).

5. Filtering device (9) according to claim 7, wherein the outlet opening (13) is located above a butterfly valve (6) of the suction system (5).

9. Filtering device (9) according to one of the claims from 1 to 8, wherein each intake opening (12) is suitable to receive air from a dynamic air intake (20) which is obtained through a front wall (21) of the vehicle (1).

10. Filtering device (9) according to claim 9 and comprising for each intake opening (12) a tubular intake pipe (22) which is suitable to connect the intake opening (12) with the dynamic air intake (20) which is obtained through the front wall (21) of the vehicle.

11. Vehicle (1) comprising:

an engine compartment (2);

an engine (4) which is housed inside the engine compartment (2); and

a filtering device (9) for the air taken in by an engine (4), which is located inside the engine compartment (2) above the engine (4) and is produced according to one of the claims from 1 to 10.

Drawing