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DESCRIPTION

Technical field

The present invention relates to an element vehicle for thermal insulation, in particular motor vehicles, and to a relative method for manufacturing said element.

Technological background

In the field of thermal insulation some material are known, which include mineral fibers.

A material of the type mentioned above can comprise glass fiber, basalt fiber, etc.. These material are sometimes used to create products for thermal insulation.

Prior art solutions are affected by some drawbacks.

One drawback lies in the poor performances in terms of insulation, which makes it necessary for manufacturers to produce very large insulating products. This aspect has negative repercussions, in particular, in the field of vehicle thermal insulation, such as motor vehicles.

A further drawback lies in the production process with which products for thermal insulation are produced, which turn out to be scarcely efficient both from an economic point of view and from a technical point of view.

Summary of the invention

An object of the present invention is to provide an element for vehicle thermal insulation, which is able to solve this and other drawbacks of the prior art and which, at the same time, can be produced in a simple and low-cost fashion .

In particular, one of the technical problems solved by the present invention is that of providing an element for thermal insulation, which guarantees high performances.

A further object is to provide an element for thermal insulation, which has a shape that is convenient for the use for which it is intended.

A further object is to provide a method for manufacturing an element for vehicle thermal insulation.

According to the present invention, there is provided an element for vehicle thermal insulation having the features set forth in the appended independent claim.

The appended claims are an integral part of the technical teaches provided in the following detailed description concerning the present invention. In particular, the appended claims define some preferred embodiments of the present invention and describe optional technical features.

Brief description of the drawings

Further features and advantages of the present invention will be best understood upon perusal of the following detailed description, which is provided by way of example and is not limiting, with reference, in particular, to the accompanying drawings, wherein:

- figure 1 is a perspective view of an element for thermal insulation manufactured according to an explanatory embodiment of the present invention; and

- figure 2 is a front view of the element shown in figure 1 ;

- figure 3 is a cross-sectional view of the element shown in figure 2, along line III-III;

- figure 4 is a cross-sectional view of the element similar to the one shown in figure 3, but representing an element for thermal insulation manufactured according to a further embodiment of the present invention;

- figure 5 is a cross-sectional view of the element shown in figure 4, along line V-V;

- figure 6 is a cross-sectional view similar to the one of figure 2, but representing an element for thermal insulation manufactured according to another embodiment of the present invention;

- figure 7 is a cross-sectional view similar to the one of figure 2, but representing an element for thermal insulation manufactured according to a further embodiment of the present invention;

- figure 8 is a perspective view of an exhaust manifold according to an explanatory embodiment of the present invention; and

- figure 9 is a cross-sectional view of the manifold shown in figure 8.

Detailed description of the invention

With reference, in particular, to the accompanying figures, it is shown an element 10 for vehicle thermal insulation, in particular motor vehicles. As a person skilled in the art can easily understand, this use of element 10 should not be interpreted as limiting for the scope of protection of the present invention, since, as a matter of fact, it can also be used, if necessary, for other types of vehicles, for example vehicles for sea and lake navigation or aircrafts.

The invention is intended to be mainly applied to heat sources, such as the ones resulting from the presence of an engine, in particular an internal combustion engine.

Element 10 for vehicle thermal insulation comprises mineral fiber.

Element 10 has a substantially tubular shape and a cavity 24, and it comprises:

- an outer surface 20; and

- an inner surface 22, which faces said cavity 24.

Furthermore, element 10 is manufactured by means of a needle-punching process, to which said mineral fiber is subject .

Conveniently, said cavity 24 houses a foreign body, such as a heat source.

Examples of said foreign body can be parts or components of a vehicle that tend to heat up when they are working, for example parts of the engine, exhaust pipes, etc.. However, the use of element 10 associated with a foreign body suited to be subject to heating should not be interpreted as strictly limiting for the scope of protection of the present invention. As a matter of fact, the foreign body can also be - alternatively- a cold source or an object that tends to cool down when it is working, for example pipes in which a coolant flows within a conditioning or refrigeration system.

Preferably, the mineral fiber comprises basalt fiber.

Optionally, the mineral fiber consists of the sole basalt fiber .

Alternatively, the mineral fiber can comprise glass fibers, carbon fibers, and other known mineral fibers.

Figures from 1 to 7 show, by way of a non-limiting example, and with special reference to figure 5, that the tubular shape has a circular cross section. However, it is also possible to have a tubular shape having a cross section with a different shape, for example one that transversely defines an oval or elliptical profile.

Figure 3 shows an explanatory embodiment of the present invention, wherein element 10 comprises a layer 29 of mineral fiber (e.g. basalt fiber), which, in turn, has:

- the outer surface, which is indicated with 20 and faces outwards, and

- the inner surface, which is indicated with 22 and faces cavity 24.

Figure 4 shows a further embodiment of the invention comprising :

- an outer layer 30 of mineral fiber, whose radially outer portion defines said outer surface 20; and

- an inner layer 32 of mineral fiber, whose radially inner portion defines said inner surface 22.

In the embodiment shown, inner layer 30 is transversely or radially adjacent to outer layer 32; in other words, layers 30 and 32 border one another and are in contact with one another.

As shown, in particular, in figure 5, said outer layer 30 and inner layer 32 of mineral fiber have a circular annular cross section and are concentric.

Preferably, at least one between said outer surface 20 and said inner surface 22 is associated with a metal coating layer.

In particular, the metal layer can be associated so as to coat surfaces 20 and 22 on the inside and/or outside.

Clearly, the aforesaid metal layer can be applied to the embodiment described above with reference to figure 3, which means the one in which element 10 comprises one single layer of mineral material indicated with 29. In this way, the metal layer can coat outer surface 20 and/or inner surface 22, for example according to one of the following configurations:

- the metal layer coats the sole outer surface 20;

- the metal layer coats the sole inner surface 22; and - the metal layer coats both outer surface 20 and inner surface 22.

With reference to figure 6, it shows another embodiment of the invention, wherein element 10 has inner layer 32 and outer layer 30, as described above. In the embodiment, the sole inner layer 32 - in correspondence to the inner surface - is coated with the metal layer, here indicated with number 42.

With reference to figure 7, a further embodiment of the invention is shown, which is similar to the one shown in figure 6. More specifically, unlike what is shown in figure 6, element 10 comprises a pair of metal layers, wherein the first metal layer 40 and the second metal layer 42 coat inner layer 30 and inner layer 32, respectively.

As an alternative to the embodiments shown in figures

6 and 7, the sole outer layer 30 - in correspondence to outer surface 20 - can be coated with the metal layer (details not shown) .

According to a further embodiment, which is not shown herein, element 10 can comprise the pair of layers of mineral fibers, as described above, and between the two layers of mineral fibers there in interposed a metal layer. In other words, in this embodiment, the metal layer transversely or radially separates the two layers of mineral fibers from one another.

According to further embodiments, which are not shown herein, element 10 can comprise a plurality of layers of mineral fiber, a larger number than the pair of layers shown, for example, in figures 6 and 7. This embodiment can also involve the use of one or more metal layers, which can coat the layers of mineral fiber in at least one of the following configurations (or, if necessary, combined with one another) :

- the metal layer coats the outer surface carried by the layer of mineral fiber arranged in a transversely or radially outer position;

- the metal layer coats the inner surface carried by the layer of mineral fiber arranged in a transversely or radially inner position; and

- the metal layer is interposed in the space arranged between two transversely or radially adjacent layers of mineral fiber.

Optionally, in the different embodiments shown herein, the aforesaid metal layer can be provided with a plurality of holes (not shown) . The holes carried by the metal layer can have different shapes and sizes, according to the technical needs of the case in point; for example, these holes can be circular holes, slits, holes with a geometric shape, holes with an irregular shape, etc..

According to a further variant, in the different embodiments described above the metal layer forms a metal net .

In other variants, the aforesaid metal layer is substantially continuous, namely without holes.

With a non-limiting reference to the examples shown and discussed herein, the particular substantially tubular shape of cavity 24, is adapted to house a foreign body with an oblong shape, such as an element having a substantially tubular shape as well, such as for example a pipe, an exhaust duct of an internal combustion engine, etc.. In this way, element 10 for vehicle thermal insulation surrounds the foreign body, thus guaranteeing better performances in terms of insulation and ensuring greater compactness for the assembly made up of element 10 for thermal insulation and the foreign body.

As already mentioned above, an element 10 for thermal insulation similar to the one described above can easily be included in different types of vehicles, such as for example: a car, a motor vehicle, a motorcycle, and if necessary a ship, an aircraft, etc..

The present invention also relates to an exhaust manifold, generally adapted to expel exhaust gases generated by an endothermic engine and comprises an element 10 manufactured according to any one of the different embodiments and variants described above.

By way of example, figure 8 shows an exhaust manifold 50 comprising an inlet duct 52 and an outlet duct 54, among which there is interposed an intermediate portion (especially, though not necessarily, having a larger diameter compared to said ducts 52, 54), around which there is arranged element 10 according to the present invention.

As it can be seen in the explanatory embodiment shown in figure 9, element 10 included in the exhaust manifold 50 has a structure that resembles the one shown in figures from 4 to 8; namely, it comprises:

- outer layer 30 of mineral fiber defining said outer surface 20; and

- inner layer 32 of mineral fiber defining said inner surface 22.

In the preferred variant shown herein, a third layer 56 is arranged on the inside of said inner layer 32 of mineral fiber. In particular, the third layer 56 is arranged on the inside of cavity 24 formed by inner surface 22 and is in contact with said inner surface 22.

More specifically, the third layer 56 can comprise any material; conveniently, it comprises a catalytic material, a soundproofing material, etc.. In this way, the manifold can gain advantageous properties, such as a smaller environmental and/or noise pollution.

The third layer 56 has a passage duct 58, adapted to allow a fluid, such as for example an exhaust gas, to flow between inlet duct 52 and outlet duct 54.

According to a convenient embodiment, element 10 included in exhaust manifold 50 is coated, on the outside, with a protection layer 60 (for example made of metal), which is useful to protect the mineral fibers of element 10 from wear, abrasions, impacts, humidity, water, dirt, etc..

According to an embodiment, which is not shown herein, element 10 included in exhaust manifold 50 comprises one or more metal layers 40, 42, similarly to the embodiments described above. To this regard, coating layer 60 mentioned above can coincide with outer metal layer 40 described with reference to some of the embodiments discussed above, to which reference is made for the sake of brevity.

Furthermore, according to the present invention there is provided a method for manufacturing an element 10 for vehicle thermal insulation comprising the following steps:

- providing at least one thin layer of mineral fiber including (and, more preferably, consisting of) basalt fiber; and

- causing said thin layer of mineral fiber to undergo a needle-punching process so as to cause said thin layer to gain a substantially tubular shape for creating said element 10.

Preferably, the step of providing a thin layer of mineral fiber comprises the following operating steps:

- providing a mattress of said mineral fibers, and

- causing said mattress to undergo a carding process, so as to obtain the thin layer of mineral fiber.

More preferably, between the operating step of providing a mattress of mineral fibers and the operating step of causing said mattress to undergo a carding process, a further operating step is carried out in order to blend the mineral fibers of the aforesaid mattress.

According to a preferred embodiment of the present invention, during the carding step, a plurality of overlapping layers of mineral fiber are obtained in a known manner and are then subject to the needle-punching process, so as to make them "thick", thus obtaining a compact tubular structure for element 10.

In particular, the needle-punching step, which is carried out by shaping the plurality of overlapping thin layers into a compact tubular structure, can be performed in a fashion known to a person skilled in the art, for example using the relative machine.

Conveniently, after the needle-punching step, there is provided the step of cutting element 10, so that is has a predetermined length.

For example, if the machine for carrying out the needle-punching process expels the finished tubular element 10 in a continuous manner, element 10 is cut at predetermined time and/or space intervals, so as to obtain a plurality of elements 10 with a predetermined length.

At the end of the needle-punching process, a nonwoven fabric of mineral fiber, preferably basalt fiber, is obtained .

Naturally, the principle of the present invention being set forth, embodiments and implementation details can be widely changed relative to what described above and shown in the drawings as a mere way of non-limiting example, without in this way going beyond the scope of protection provided by the accompanying claims.