Technical field
[0001] The present invention relates to a housing of air filter for internal combustion
engines, and to an air filter incorporating said housing.
Prior art
[0002] As known, internal combustion engines, in particular vehicle engines, need a filter
for cleaning air sucked from the outside environment and directed to the combustion
chambers.
[0003] In many cases, the air filter consists of a cartridge of filtering material, housed
within a sealed housing, mainly equipped with air inlet and outlet ports and with
a holding recess for the cartridge. Inside the housing, there is defined a path compelling
the inflowing air to pass through the cartridge before flowing out through the outlet
port. The cartridge may be made for instance of pleated paper and be of different
shapes and sizes.
[0004] EP 1 433 947 discloses an air filter for IC engines including a housing, a cartridge equipped
with a fluid-tight gasket, and air inlet and outlet ports. The cartridge is housed
within the housing in a seat closed by a removable cover, which is secured to the
housing by means of screws arranged along a cover edge cooperating with a corresponding
edge of the housing in order to sandwich the cartridge gasket therebetween, to ensure
the required fluid seal between the cartridge and the housing.
[0005] EP 1 593 834 discloses another example of a housing for an air filter, which can be located in
the upper part of the engine compartment. A seat for the filtering element communicating
with air inlet and outlet ducts is provided and the housing includes a cover secured
by means of screws along an abutment edge retaining the gasket for the cartridge.
[0006] FR 2 922 269 discloses a further example of a housing for an air filter for IC engines, including
a container equipped with a cover and a side opening for the introduction of the filtering
cartridge, which is surrounded by a frame equipped with a gasket. The frame and the
gasket are sandwiched between the container and the cover when the housing is closed.
[0007] As known, the housings of air filters are to be designed so as to meet two requirements
that not always are compatible: on the one side, the housing is to internally define
an air flow path such that air flows through the cartridge, which in turn is to be
sized so as to meet the needs of the engine the filter is associated with, and on
the other side the housing is to fit to the conformation of the engine and the other
devices associated therewith, and in particular to the available room in the engine
compartment.
[0008] The latter requirement is particularly felt in the automotive field, where component
size reduction, while possibly improving the efficiency and the reliability of the
same components, is a strongly felt need.
[0009] The prior art devices are not sufficiently compact to meet the modern requirements
of size reduction, and thus it is a main object of the present invention to provide
a housing of air filter for internal combustion engines, which has a reduced size
while maintaining a considerable filtering capacity.
[0010] It is a further object of the invention to provide a housing of the above kind, which
is cheap and easy to be manufactured so that it can be industrially produced on a
large scale.
Description of the invention
[0011] The above and other objects are achieved by the housing and the filter according
to the invention, as defined in the appended claims.
[0012] According to a first advantageous aspect of the invention, the fluid seal between
the gasket surrounding the filtering element and the mechanical fastening between
the cover and the container of the housing take place in non-coplanar areas. More
particularly, according to the invention, the fluid seal and the abutment between
the cover and the container of the housing are defined in different planes, preferably
in substantially parallel planes. Thanks to this feature, it is advantageously possible
to reduce the housing thickness so that it is very close to the thickness of the filtering
element only.
[0013] Advantageously, still in accordance with the invention, thanks to the arrangement
of the air ducts that extend along the walls of the holding recess for the cartridge,
also the longitudinal and transversal sizes of the housing are considerably reduced.
Notwithstanding this, the filter generally maintains a high filtering capacity, determined
by the wide surface for passage of air towards the holding recess in which the cartridge
is held and from the holding recess towards the outlet duct.
[0014] The housing of air filter for internal combustion engines according to the invention
is thus extremely thin and compact and it can be located also in engine compartments
of small cars, for instance runabouts, in particular between the engine and the bonnet.
[0015] Another advantage of the invention is the possibility of making the housing by using
a reduced number of components.
[0016] A further, but not the last, advantage of the invention is that the housing made
in this manner is aesthetically appealing tanks to the provision of a substantially
flat top shell, of which the shape and the size can moreover be defined at will, for
instance in order to hide engine components.
Brief Description of the Figures
[0017] A preferred embodiment of the invention is disclosed by way of non-limiting example
with reference to the accompanying drawings, in which:
- Fig. 1 is a top perspective view of the housing according to the invention;
- Figs. 2A and 2B are top and bottom exploded views, respectively, of the filter according
to the invention;
- Fig. 3 is a bottom perspective view of the housing shown in Fig. 1;
- Fig. 4 is a bottom plan view of the housing shown in Fig. 1;
- Figs. 5 and 6 are cross sectional views taken along lines V - V and VI - VI, respectively,
of Fig. 4.
Description of a Preferred Embodiment
[0018] Referring to Fig. 1, the housing of air filter for internal combustion engines according
to the invention has been generally denoted by reference numeral 11 and is shown from
above, i.e. substantially as it would appear when opening the bonnet of a vehicle
into which the filter is incorporated according to a standard arrangement.
[0019] Turning to Figs. 2A, 2B and 3, housing 11 includes a container 13 where a holding
recess 15 housing a removable cover 31 is defined.
[0020] A duct 19 for the dirty air, equipped with an aperture 21 for the entrance of air
to be filtered, and a duct 23 for the cleaned air, equipped with an aperture 25 for
the exit of the filtered air, are further defined in container 13
[0021] Container 13 further includes an upper base 27, substantially made as a shell in
the illustrated example, which further preferably defines a corresponding upper portion
of the walls of ducts 19 and 23. Said base 27 moreover closes upwards one of the bases
of holding recess 15 and preferably it is permanently associated with container 13,
for instance by welding or gluing, when housing 11 is being made.
[0022] Holding recess 15 is further equipped in its lower portion, i.e. on the side opposite
upper base 27, with an aperture 29 through which removable cover 31 can be introduced
into holding recess 15, until closing said aperture 29.
[0023] According to the invention, holding recess 15 has a substantially prismatic shape,
preferably a parallelepiped shape with two parallel opposite short walls 15a and two
parallel opposite long walls 15b.
[0024] Introduction of cover 31 into holding recess 15 takes place according to an approach
direction substantially parallel to said side walls 15a, 15b of holding recess 15
and, in the illustrated embodiment, substantially perpendicular to the portion of
upper base 27 closing holding recess 15 upwards.
[0025] Dirty air duct 19 communicates with holding recess 15 through an aperture 20 provided
along one of the side walls of said holding recess 15. In the illustrated example,
aperture 20 is located on one of the long side walls 15b of holding recess 15.
[0026] Clean air duct 23 communicates with holding recess 15 through a passageway 24 defined
between base 27 and the side walls of holding recess 15. In the illustrated example,
said passageway 24 substantially extends between base 27 and two adjacent side walls
15a, 15b.
[0027] Cover 31 internally houses a filtering element 17, which may include a prism-shaped
or, in the illustrated example, parallelepiped-shaped cartridge. In an exemplary embodiment,
the cartridge may be obtained by means of a corresponding panel of pleated paper or
other material with appropriate separation properties. The cartridge will be further
provided with a peripheral sealing gasket 17a, preferably integrated and made of plastic
material, for instance a polyurethane foam. Said gasket 17a extends around the panel
defining filtering element 17 and projects radially outwards from the side walls of
said filtering element 17.
[0028] Cover 31 includes a body with complementary shape to holding recess 15, thus substantially
parallelepiped-shaped in the illustrated example, with a base 30 and two parallel
opposite short walls 31a and two parallel opposite long walls 31b. Walls 31a, 31b
surround a holding recess 32, parallelepiped-shaped in the illustrated example, housing
filtering element 17.
[0029] An aperture 22 is provided on the wall of cover 31 facing air inlet aperture 20 when
cover 31 is housed in holding recess 15. In the illustrated example, said aperture
22 is provided on one of long walls 31b.
[0030] Said walls 31a, 31b are further provided with a peripheral edge 36 projecting radially
outwards from walls 31a, 31b, and preferably extending without interruptions around
the whole cover 31. Said edge 36 forms a corresponding abutment for cover 31, allowing
the mechanical fastening of cover 31 into holding recess 15. Cover 31 may be fastened
to container 13 by means of fastening means, such as for instance screws 33 passing
through holes provided in abutment edge 36 and intended to engage container 13. By
removing screws 33, cover 31 can therefore be removed from holding recess 15, to allow
replacing filtering element 17 located inside cover 31.
[0031] Removal of cover 31 from holding recess 15 takes place according to a removal direction
substantially parallel to said side walls 15a, 15b of holding recess 15 and, in the
illustrated embodiment, substantially perpendicular to the portion of upper base 27
closing holding recess 15 upwards.
[0032] According to the invention, the depth of holding recess 32 is chosen so that filtering
element 17 can be received in recess 32 by leaving the portion surrounded by peripheral
gasket 17a outside, and said gasket will abut against the axially sealing free edge
34 of side walls 31a, 31b of cover 31.
[0033] Correspondingly, the depth of holding recess 15 defined in container 13 is chosen
so that, when cover 31 is introduced into holding recess 15 and edge 36 abuts against
the corresponding abutment edge 18 of walls 15a, 15b of holding recess 15, gasket
17a is in contact with a peripheral sealing edge 16 projecting into holding recess
15 and extending on a plane spaced apart from base 27 in order to define passageway
24 between said sealing edge 16 and base 27. It is evident that sealing edge 16 and
edge 34, being to define the fluid seal with gasket 17a, preferably extend each on
a respective single plane and without interruptions.
[0034] In such a manner, by closing cover 31 by means of screws 33, the flattening of gasket
17a between sealing edge 34 and sealing edge 16 and the consequent fluid seal are
determined, thereby ensuring that dirty air entering holding recess 15 through aperture
20 passes through filtering element 17 before being exhausted through passageway 24.
On the contrary, the closure between sealing edge 36 and sealing edge 18 needs not
to be a fluid-tight one, since air possibly entering between both edges is directed
towards the region where air to be filtered is present.
[0035] From the above description it will be appreciated that, according to the invention,
the fluid seal between gasket 17a surrounding filtering element 17 and the mechanical
fastening between cover 31 and container 13 take place in separate areas, more precisely
non-coplanar areas. More particularly, according to the invention, the fluid seal
and the abutment between cover 31 and container 13 are defined on different planes.
The plane on which the mechanical fastening between cover 31 and holding recess 15
occurs is indeed separate from the plane on which fluid seal is determined thanks
to gasket 17a. Actually, according to the invention, abutment edge 36 for fastening
screws 33 lies on a plane other than that on which gasket 17a extends. Said planes
are spaced apart by a distance of the order of the thickness of cover 31, and consequently
of the order of the thickness of filtering element 17, typically a few centimetres,
for instance in the range 3 to 10 cm.
[0036] As it can be better seen in Fig. 4, clean air duct 23 extends over at least part
of two adjacent walls of holding recess 15, which in the illustrated example are a
short wall 15a and a long wall 15b of said holding recess 15 and, correspondingly,
of cover 31, and are parallel to transversal axis "T" and longitudinal axis "L", respectively.
More precisely, always referring to the illustrated example, a first section 23a of
duct 23 extends along short wall 15a of holding recess 15 and a second section 23b
extends along the adjacent long wall 15b. Moreover, ducts 19, 23 will preferably have
a wall portion in common with walls 15a, 15b.
[0037] Moreover, according to the invention, dirty air duct 19, besides extending over at
least part of one of the walls (long wall 15b in the illustrated example), also has
a corresponding section 19a extending along base 30 of said cover 31.
[0038] Similarly, clean air duct 23, besides extending along at least part of two adjacent
walls of holding recess 15, as said above, also extends along that portion of base
27 defining the base of said holding recess 15, thereby defining passageway 24 for
clean air outflow.
[0039] Thanks to a such an arrangement of ducts 19 and 23 relative to holding recess 15
for filtering element 17, air flowing though filtering element 17 housed in holding
recess 15 can reach clean air duct 23 through a large surface, with considerable advantages
for the overall filtering capacity of the filter, and yet housing 11 is kept extremely
compact in particular in respect of its thickness, i.e. in the direction of vertical
axis "V" (Fig. 5).
[0040] Always in accordance with the invention, dirty air inlet duct 21 preferably extends
along part of the same long wall 15b of holding recess 15 along which section 23b
of clean air outlet duct 23 extends.
[0041] Advantageously, thanks to such an arrangement, the housing according to the invention
is extremely compact in the direction of both longitudinal axis "L" and transversal
axis "T",
[0042] Referring to Figs. 5 and 6, filtering element 17 is substantially laterally surrounded
by walls 31a, 31b of cover 31.
[0043] Moreover, the thickness of region 14 occupied by filtering element 17 in holding
recess 32 in cover 31, which cover is in turn housed in holding recess 15, and consequently
the thickness of filtering element 17, i.e. its extension in the vertical direction
of axis "V", is lower than the overall thickness of holding recess 15.
[0044] Said region 14 is positioned in cover 31 at an intermediate location, always with
reference to the vertical direction of axis "V", so that, when cover 31 is housed
in holding recess 15, in said holding recess 15 there are defined a first portion
with thickness "d1" (lower portion in Fig. 5), associated with aperture 20 of dirty
air duct 19, a second portion with thickness "d2" (upper portion in Fig. 5), associated
with clean air passageway 24 and a third portion, or intermediate region 14, with
thickness "d3", in which filtering element 17 is arranged.
[0045] According to the invention, housing 11 cab be advantageously made by assembling a
reduced number of components, each obtained by moulding plastic materials.
[0046] In the illustrated example, housing 11 is substantially made of three parts, namely
a single container, integrating air inlet and outlet ducts 19, 23 and walls 15a, 15b
of holding recess 15, shell-shaped upper base 27 and cover 31. The single container
integrating air inlet and outlet ducts 19, 23 and walls 15a, 15b of holding recess
15 is preferably permanently joined with base 27 by welding or gluing, whereas cover
31 is removably joined with the walls of holding recess 15. Moreover, said three parts
possibly have associated therewith fittings mainly intended to contribute to noise
reduction, to allow associating the housing with the air circuit and to allow fastening
the housing to the engine.
[0047] Even if the invention has been disclosed with reference to a presently preferred
particular embodiment, all obvious changes and modifications that will be apparent
to the skilled in the art are included within the scope of the invention.
1. Housing (11) of air filter for internal combustion engines, comprising:
- a container (13), where a holding recess (15) for a filtering element (17) is defined;
- a cover (31), removably housed in said holding recess (15) and in turn arranged
to house said filtering element (17);
- a duct (19) for the dirty air, communicating with said holding recess (15) through
an aperture (20) and equipped with an inlet aperture (21) for the air to be filtered;
- a duct (23) for the cleaned air, communicating with said holding recess (15) through
a passageway (24) and equipped with an outlet aperture (25) for the filtered air;
- wherein said holding recess (15) is of a substantially prismatic shape and the duct
(23) for the cleaned air extends over at least part of two adjacent walls (15a, 15b)
of said holding recess (15);
- wherein said cover (31) has side walls (31a, 31b) surrounding a holding recess (32)
for the filtering element, said side walls defining a sealing edge (34) for a fluid-tight
gasket (17a) for said filtering element;
- wherein said cover (31) has a peripheral edge (36) projecting radially outwards
from said side walls and defining an abutment edge for said cover (31), allowing the
mechanical fastening of the cover (31) into the holding recess (15);
- wherein said sealing edge (34) for the fluid-tight gasket (17a) and said abutment
edge (36) for said cover are non coplanar.
2. Housing according to claim 1, wherein said sealing edge (34) for the fluid-tight gasket
(17a) and said abutment edge (36) for said cover (31) extend on respective, substantially
parallel planes.
3. Housing according to claim 2, wherein said sealing edge (34) for the fluid-tight gasket
(17a) and said abutment edge (36) for said cover (31) extend on planes spaced apart
by a distance substantially equal to the thickness of the cover (31).
4. Housing according to claim 1 or 2 or 3, wherein the container (13) of the housing
further includes an upper base (27) defining a corresponding upper portion of the
walls of the air ducts (19, 23), and wherein said base (27) closes one of the bases
of the holding recess (15) for the filtering element (17), said holding recess (15)
being further equipped, on the side opposite said upper base (27), with an aperture
(29) through which the removable cover (31) can be introduced into the holding recess
(15), until closing said aperture (29).
5. Housing according to claim 4, wherein the holding recess (15) has a substantially
parallelepiped shape, and wherein the introduction of the cover (31) into the holding
recess (15) takes place according to an approach direction substantially parallel
to said side walls (15a, 15b) of the holding recess (15) and substantially perpendicular
to the portion of the upper base (27) closing the holding recess (15).
6. Housing according to any preceding claim, wherein the holding recess (15) has two
parallel opposite short walls (15a) and two parallel opposite long walls (15b).
7. Housing according to any preceding claim, wherein the cover (31) includes a body with
complementary shape to the holding recess (15) and having a base (30) and side walls
(31a, 31b), and wherein the side walls (31a, 31b) surround said holding recess (32)
for the filtering element (17).
8. Housing according to claims 6 and 7, wherein said cover (31) includes a substantially
parallelepiped-shaped body, with two parallel opposite short walls (31a) and two parallel
opposite long walls (31b).
9. Housing according to any preceding claim, wherein the cover (31) is fastened to the
container (13) by means of screws (33) passing through holes provided in the peripheral
edge (36) projecting radially outwards from said side walls and defining an abutment
edge for said cover (31), said screws being intended to engage the container (13).
10. Housing according to any preceding claim, wherein the depth of said holding recess
(32) in the cover (31) is chosen so that the filtering element (17) can be received
in said holding recess (32) by leaving the portion surrounded by peripheral gasket
(17a) outside.
11. Housing according to claim 10, wherein the depth of the holding recess (15) defined
in the container (13) for said cover (31) is chosen so that, when the cover (31) is
introduced into the holding recess (15), the fluid-tight gasket (17a) is in contact
with a peripheral sealing edge (16) projecting into the holding recess (15), so that,
by closing the cover (31) by the screws (33), the flattening of the gasket (17a) between
the sealing edge (34) of the cover and the sealing edge (16) of the holding recess,
and the consequent fluid seal, are determined, thereby ensuring that dirty air entering
the holding recess (15) passes through the filtering element (17) before being exhausted.
12. Housing according to claim 11, wherein said peripheral sealing edge (16) projecting
into the holding recess (15) extends on a plane spaced apart from the base (27) in
order to define the air outlet passageway (24).
13. Housing according to any preceding claim, wherein said cover has, on its side wall,
an aperture (22) facing the air inlet aperture (20) when the cover (31) is housed
in the holding recess (15).
14. Housing according to any preceding claim, wherein the dirty air inlet duct (19) preferably
extends over part of the same wall of the holding recess (15) over which a section
of the clean air outlet duct (23) extends.
15. Air filter for internal combustion engines, including a housing (11) according to
any of claims 1 to 14, in which there is housed a filtering element (17) including
a panel of a material with appropriate separation properties provided with a peripheral
sealing gasket (17a) surrounding the filtering element (17) and projecting radially
outwards from the side walls of said panel.