motors

DESCRIPTION

The invention relates to a compact panel-like air filter cartridge with improved efficiency for l.C. motors.

Panel-like air filter cartridges with several shapes and sizes are known in the art. Such cartridges usually comprise a pack of filtering material having a prismatic shape. The filtering material has an upstream face and a downstream face relative to the air flow. The upstream face is the first to be hit by the impure air flow passing through the cartridge. The impure air flow releases particles of dirt while passing through the filtering material. The purified air flow exits the cartridge through the downstream face. The upstream face and the downstream face are usually flat and lie on mutually parallel planes. Overall, therefore, this type of cartridges has the shape of a parallelepiped panel. Cartridges with oblique faces or crooked shapes are also known, devised for adapting to the particular shape of the cartridge container, which in turn has to adapt to the space, sometimes limited and irregular, available in the motor compartment. An example of a cartridge of the aforementioned known type is described in WO 2013/093685.

In the field, the need for air filter cartridges with high filtration capacity and compact size is particularly felt. The main object of the present invention is to meet such need. Therefore the object of the present invention is to provide a panel-like air filter cartridge with high efficiency that can be made with small size and thus adapt to motor compartments which are small-sized or in which there is limited space for the filter cartridge.

This object is achieved with the characteristics claimed in the appended Claim 1. Further objects of the invention are achieved with the characteristics claimed in the dependent claims.

The cartridge according to the invention is of the kind comprising a pack of filtering material, preferably made of pleated paper. The cartridge further comprises a gasket defining at least two coplanar peripheral frames having a side in common. The gasket may further comprise further frames coplanar to the first two frames and provided or not with filtering material. A first frame surrounds the downstream face of the cartridge and a second frame surrounds a cartridge portion free from filtering material. The gasket is made of polyurethane material, preferably of a hot-melt, hardened polyurethane resin. The purpose of the gasket is to guarantee adequate sealing between the cartridge and the walls of the housing of the filter box in which the cartridge is housed.

Advantageously, the invention provides that the upstream face defines at least two flat portions lying on non-coincident planes, wherein the thickness of the pack of filtering material at the first portion is greater than the thickness of the pack at the second portion. Preferably, the second portion, in which the cartridge has a smaller thickness, lies on a plane oblique relative to the downstream face. According to the invention, it is therefore possible to increase the overall area of the surface of the upstream face and reduce the space requirement of the cartridge and, consequently, of the housing of the housing of the filter box. When the second portion is oblique, the thickness of the filtering material pack of the cartridge is progressively reduced, depending on the inclination of the oblique portion, along a preferably transverse direction. According to the invention, the thickness of the filtering pack along a first longitudinal face is about one third of the thickness of the cartridge along the opposite longitudinal face. In this way, the filtering capacity of the pack of filtering material remains high and the size of the cartridge is remarkably reduced. In particular, the overall height requirement of the cartridge is reduced, this involving the advantage that the cartridge can be incorporated in small-sized spaces.

According to a particular aspect of the invention, the gasket comprises an outer side in which an oblique portion is defined. This arrangement allows to reduce the length of one of the sides of the cartridge and, correspondingly, the overall size of the cartridge and, consequently, of the housing of the filter box.

The invention will be described below with reference in particular to the annexed figures, in which:

- Fig. 1 is a perspective view from above of a filter cartridge made according to the invention;

- Fig. 2 is a top plan view of the cartridge of Fig.1;

- Fig. 3 is a plan view of a side face of the cartridge of Fig.1;

- Fig. 4 is a bottom plan view of the cartridge of Fig.1;

- Fig. 5 is a plan view of a front face of the cartridge of Fig.1.

Referring to the annexed figures, there is illustrated a panel-like air filter cartridge 11 made according to the invention. The cartridge 11 is arranged to be inserted into the air intake circuit of an I.C. motor. The cartridge 11 comprises a pack 13 of filtering material. The pack 13 has a prismatic shape in which an upstream face 15 and a downstream face 17 are defined. The upstream face 15 serves for inletting the air to be purified. The downstream face serves for outletting the air that has been purified.

The cartridge 11 comprises a polyurethane peripheral gasket 19. The gasket 19 defines a first frame 21 and a second frame 23. The first frame and the second frame 23 are mutually coplanar and have a side 25 in common. The first frame 21 further surrounds the downstream face 17. The second frame 23 surrounds a portion 27 of the cartridge 11 that is free from filtering material. In the illustrated example, the gasket 19 comprises two frames only, however, according to the invention, said gasket 19 may also comprise further frames coplanar to the first two frames and provided or not with filtering material.

According to the invention, the downstream face 17 is substantially flat. Still according to the invention, the upstream face 15 comprises a first flat portion 29 parallel to the downstream face 17, and a second flat portion 31 oblique relative to the downstream face 17. Advantageously, still according to the invention, the area of the surface of the second portion 31 oblique relative to the upstream face 15 is at least equal to the area of the surface of the first portion 29 of the upstream face 15.

According to a particular aspect of the invention, the area of the surface of the second portion 31 oblique relative to the upstream face 15 is at least 5% and more preferably at least 10% larger than the area of the surface of the first portion 29 of the upstream face 15.

According to the invention, the pack 13 of filtering material defines a longitudinal section 33 and a cross-section 35 that are perpendicular to the downstream face 17 and to the first portion 29 of the upstream face 15, the longitudinal section having a substantially rectangular shape and the cross-section 35 having a substantially rectangular trapeze-like shape.

As can be appreciated particularly from Fig. 3, the thickness of the filtering material pack 13 of the cartridge 11 is progressively reduced, depending on the inclination of the second, oblique portion 31, along the transverse direction. In a preferred embodiment, the second, oblique portion 31 is inclined at an angle a of about 30° relative to the plane of the first portion 29 of the upstream face 15. According to the invention, the thickness di of a first front face of the pack 13 is about one third of the thickness d ₂ of the opposite face. More preferably, the thickness di is comprised between 1/3 of the thickness d ₂ of the opposite face and 1/8 of said thickness d ₂ . According to another particular aspect of the invention, the filtering material pack 13 comprises pleated paper in which the pleats of the paper are mutually parallel and arranged longitudinally, i.e. parallel to the longitudinal section 33.

According to the invention, the first frame 21 has a substantially rectangular shape with its sides being parallel in pairs and rectilinear, whereas the second frame 23 has an approximately rectangular shape with a transverse side 37 having an oblique portion 37a adjoining a transverse rectilinear portion 37b and a perpendicular longitudinal side 39. Still according to the invention, the frames, be they two as in the illustrated example or more than two, may have a rectangular trapeze-like shape and have or not have a side provided with an oblique connecting portion. Advantageously, in this way the longitudinal side 39 of the gasket 19 is shorter than the opposite side 41 and thus the overall size of the cartridge is reduced.

The invention as described and illustrated is capable of variants and modifications.