WO2023042174A1

WO2023042174A1 - Ventilation grid for electronic module

Info

Publication number: WO2023042174A1
Application number: PCT/IB2022/058834
Authority: WO
Inventors: Leonardo Busi
Original assignee: Leonardo Busi
Priority date: 2021-09-20
Filing date: 2022-09-19
Publication date: 2023-03-23

Abstract

A ventilation grid (1) is provided to protect a window (20) in an electronic module (M), and comprises a body (10) and a plurality of fins (14). The fins (14) are shaped with a respective profile, in which the outer part (141) has an ogive section, which is larger than the inner part (140), the fins comprising a straight central fin (14C) and two sets of lateral fins (14L, 14R), with a dihedral profile, in which the inner part (140) is parallel to the central fin (14C) and the outer part (141) is inclined outwards. The so-shaped fins (14) hide the internal components as much as possible from being seen from the outside, while allowing the free passage of air from the outside to the inside of the electronic module (M).

Description

VENTILATION GRID FOR ELECTRONIC MODULE

TECHNICAL FIELD

The present invention relates to the technical field concerning casings for electronic modules of various types, for example modules constituting integrated high frequency transmission systems used in radio and television stations.

More in particular, the invention relates to a ventilation grid which is placed so as to cover the windows, made in said casings to allow corresponding electric fans to draw fresh air from the outside, in order to cool the circuits and electronic components inside the module.

BACKGROUND ART

The purpose of a ventilation grid, in this case and in general, is to prevent foreign bodies which exceed certain dimensions from entering the window, i.e. from reaching the electric fan situated therebehind, and which could be sucked in and damage the internal components.

The just mentioned protection function must be combined with a permeability to the flow of air that is as high as possible, i.e. the grid must not form an obstacle for the air entering the module, such as to generate undesirable turbulence and pressure losses.

When an electronic module is provided with at least one of these windows situated in such a position as to be always visible from the outside, for example when the module is aimed at being recessed fitted in a "rack" type cabinet, either alone or together with other modules of the same type, the grid is required to fulfil also other functions, additional to the strictly functional ones, but no less important from a commercial point of view.

One of these additional functions relates to the aesthetic aspect of the grid, which must be attractive both when it is alone and when there are a number of grids, arranged in vertical and/or horizontal rows.

Another additional function consists in "hiding" the inner part of the module from being seen, since the rear electric fan, when in operation, becomes optically "transparent".

Finally, it is important that the grid retains a limited production cost, proportionate to its function. ventilation grids of prior art, both for the indicated technical sector and more generally, range in a vast array of forms that it is impossible to list; one can only distinguish between mesh grids and fin grids.

TECHNICAL PROBLEM

None of the known solutions was satisfactory for different, and sometimes conflicting, requirements that one would like to meet; the enclosed Figures 1 , 2, 3 of prior art illustrate an example honeycomb mesh grid which, despite its excellent functional characteristics, is deficient in particular in terms of ability to cover what is situated therebehind (see in particular Figs. 2 and 3).

The material used for the grids and the adopted production process affect the unit cost of each grid.

For example, the known illustrated grid is made by injection moulding and, as it is well known, there must be no so-called undercuts in the mould, as they would prevent the part from being removed unless further construction complications were added to the mould. Furthermore, the high cost of an injection mould is only justified for large-scale production.

OBJECTS OF THE INVENTION

Therefore, it is an object of the present invention to propose an original ventilation grid for an electronic module, which falls within the group of fin grids, carefully designed to obtain high fluid-dynamic performance and, at the same time, to have a good ability to hide what is situated therebehind.

Another object of the invention is to obtain a ventilation grid that has a good look, which appreciates the casing of the electronic module with which it is associated.

A further scope of the invention is to achieve a ventilation grid in which the longitudinal extension can be decided afterwards by cutting a semi-finished product to size.

A still further object of the invention is to design the shape of the ventilation grid so as it can be obtained by a rapid and low-cost production process.

SUMMARY OF THE INVENTION These and other purposes are fully achieved by a ventilation grid for an electronic module, the latter comprising a box-like, prism shaped casing which houses electronic circuits and components, electrically powered and defining a predetermined apparatus, and an electric fan for cooling said electronic circuits and components, with said box-like casing provided with a window having regular shape and placed in front of said electric fan in order to allow the fan to draw fresh air from the outside, said ventilation grid being provided to protect said window and comprising: a body whose perimeter, shape and surface area are at least sufficient to cover said window, with said body formed by two lateral laths mutually connected by a curved pantile-like wall, with its extrados facing outwards; an opening, made in the central area of said curved, pantile-like wall; a plurality of fins, integral with said body, projecting outwards from said curved wall, arranged parallel to said lateral laths and extending by the same length as said lateral laths, to pass through said opening, with each of said fins shaped with a respective profile, in which the external part has a section which is enlarged with respect to the internal part, aimed, in conjunction with the adjacent fins, at hiding as much as possible the interposed portions of said curved wall, or of said opening, from being seen from the outside, with said profile also aimed at letting the air flow freely, through said portions of the opening, from the outside to the inside of said box-like casing, without causing aerodynamic turbulences in the air flow itself.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the present invention will be apparent from the following description of a preferred embodiment of the ventilation grid for an electronic module, referred to above, in accordance with the claims and with the help of the enclosed drawings, in which:

Fig. 1 illustrates a ventilation grid of known type;

Figs. 2 and 3 illustrate a rack containing a plurality of electronic modules equipped with the known grid of Fig. 1 ;

Fig. 4 is a front view of the ventilation grid according to the invention; Fig. 5 is a plan view from below of Fig. 4; Fig. 6 is an axonometnc front view of the grid of Figs. 4 and 5;

Fig. 7 is an axonometric back view of the grid of Figs. 4, 5 and 6;

Fig. 8 is an axonometric view of an electronic module provided with the grid according to the invention;

Figs. 9 and 10 illustrate a rack containing a plurality of electronic modules provided with the grid according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the above-mentioned figures, the ventilation grid proposed by the present invention, as a whole, is indicated by reference number 1.

In a way known in itself, the grid 1 is provided to protect a window 20, that has a regular shape, for example rectangular, and is made in a box-like casing 2 that has a prismatic shape, preferably made of sheet metal.

The box-like casing 2 houses thereinside electronic circuits and components (not illustrated), electrically powered and defining a predetermined electronic module M, by way of non-limiting example, an integrated high-frequency transmission system, used in radio and television stations, already mentioned in the introductory note.

Still in a known manner, an electric fan (not illustrated) is provided inside said electronic module M, at said window 20, and is aimed at drawing fresh air from the outside to cool said electronic circuits and components; after having touched and cooled the latter, the input air is evacuated through other openings of the box-like casing 2, not illustrated.

The ventilation grid 1 comprises a body 10 whose perimeter, shape and surface area are at least sufficient to cover said window 20, formed by two lateral laths 11 mutually connected by a curved, pantile-like wall 12, with its extrados facing outwards.

The figures take into consideration the most common situation, in which said window 20 has a rectangular shape, therefore also the body 10 of the grid 1 has a similar conformation.

In the preferred embodiment shown in the figures, the aforesaid lateral laths 11 have a symmetrical L-like section, with the wings 11 A of said "L" turned towards the inside of the same grid 1 (horizontal with reference to the drawing in cross- section of Fig. ), to define the support abutments of the latter on said box-like casing 2.

In the central area of the curved, pantile-like wall 12, an opening 13 is made, likewise having preferably rectangular shape and extending so as to cover a major area of the same curved, pantile-like wall 12.

In the following description, certain aspects concerning the formation of the body 10 and the opening 13 will be better highlighted.

A plurality of fins 14, projecting outwards from the curved wall 12 and extending parallel to the aforementioned lateral laths 11 along the entire length of the body 10, are attached to the body 10 of the grid 1 across said opening 13 thereabove.

After the grid 1 has been mounted over the window 20, the fins 14 are arranged vertically, and more in detail they comprise: a straight central fin 14C, situated at the longitudinal centre plane of the curved, pantile-like wall 12 and projecting orthogonally therefrom; two sets of lateral fins 14L, 14R, situated symmetrically on either side of said central fin 14C, with each of said lateral fins 14L, 14R having a dihedral profile, the inner part 140 of which is parallel to said central fin 14C and the outer part 141 of which is inclined outwards.

Each of the fins 14 is advantageously shaped with a respective profile, in which the outer part 141 has an increased section with respect to the inner part 140; more particularly, it is envisaged that: said central fin 14C has the respective inner part 140 having a bladelike cross-section and the respective outer part 141 having an ogive cross-section, in each of said dihedral lateral fins 14L, 14R, the inner part 140 has a blade-like cross-section and the outer part has an ogive cross-section.

Advantageously, each lateral fin 14L has the respective outer part 141 bent so as to be parallel to the outer part of the adjacent fins 14L, the same as it occurs, mirror-like, for each lateral fin 14R with respect to the other adjacent ones of the same set.

The described profile of the fins 14, the overall protrusion of each of them, the free space therebetween, the overall number of fins 14 in relation to the size of the grid 1 , the thickness of the ogive outer part 141 , the inclination of the same outer parts 141 in the lateral fins 14L, 14R, have been carefully studied in mutual agreement in order to obtain, at the same time: also in conjunction with the pantile shape of the curved wall 12, a successful hiding from being seen from outside of the portions of the latter interposed between one fin and another, or of the opening 13 made in the same curved wall 12; a free passage of air from the outside to the inside of said box-like casing 2, between the fins 14 and through the opening 13, without creating aerodynamic turbulence in the air flow which could lead to significant pressure drops.

The ventilation grid 1 described above is advantageously made of aluminium alloy, using the extrusion technique, so that the body 10 and the aforementioned fins 14 constitute a single block.

As it is known, extrusion makes it possible to quickly obtain bars of specific length, which are then cut into pieces of a predetermined length in order to section all the single grids.

Respective channels 15 with an open circular cross-section are made in the lateral laths 11 by means of said extrusion process. The channels 15 are advantageously exploited when the grid 1 is assembled as seats for receiving selftapping fixing screws (not illustrated).

At this point of the machining, the semi-finished grid must be worked with machine tools from the inner side to make the aforementioned opening 13 in the curved, pantile-like wall 12.

Since, as specified above and instinctively comprehensible, the opening 13 must be as large as possible, it is envisaged that it extends towards the aforementioned L-shaped lateral laths 11 so as to be wider than the free space between the wings 11 A of the latter; the same wings 11A will therefore be partially reduced by the same mechanical machining performed for the production of the same opening 13.

In the case of box-like casings 2 intended to be recessed fitted in a "rack" cabinet 3, a handle 4 is advantageously provided to be removably joined to the body 10 of the ventilation grid 1 , in order to facilitate the grip during operations, in particular the extraction. In the embodiment illustrated in figure 8, the handle 4 is configured in an arc and is situated in the lower part of the casing. The arched handle 4 is placed on top of the fins 14 at an appropriate distance, so as to disturb the air flow as little as possible, if it is left in place.

The configuration of the handle 4, illustrated and described as a mere example, may be omitted, or take on any other configuration, however, without limiting the scope of the invention.

An auxiliary panel 5, of suitably coherent shape, housing connection sockets and/or LED indicator lights, may be attached to a head 1 of the grid.

The aforementioned channels 15 provided in the body 10 of the grid 1 can be advantageously used for attaching said auxiliary panel 5.

It is clear from the foregoing description that, due to the particular conformation of the body and fins, the proposed ventilation grid is able to hide properly what is therebehind from being seen.

Likewise, the numerous computer simulations carried out using suitable softwares, have made it possible to optimise all aspects of the shape of the fins in order to obtain excellent aerodynamic performance in the transit of the air flow, with minimal pressure drops and almost no turbulence.

The enclosed figures clearly show how the proposed ventilation grid can be considered aesthetically pleasing, both when looking at a single electronic module and when observing a rack with a plurality of them and with many grids arranged in horizontal and vertical rows.

The decision to use extrusion as the initial production process of the grid has provided numerous advantages, both in terms of cost, since an extrusion die is infinitely cheaper than an injection mould, and in terms of flexibility of use, delegating cutting to size of the required length and making of the opening to subsequent machine processes.

These machine processes, seemingly penalizing in terms of cost, are actually very fast, since they involve machining an aluminium alloy and are fully part of the logic of limited series production.

Moreover, aluminium can be easily aesthetically customized by anodising or painting.

However, it is understood that what is described above is illustrative and not limiting, therefore any detail variations that may be necessary for technical and/or functional reasons, both in the method and device, are considered from now on within the same protection scope defined by the claims below.

Claims

CLAIMS A ventilation grid for an electronic module (M), the latter comprising a boxlike, prism shaped casing (2) which houses thereinside electronic circuits and components, electrically powered and defining a predetermined device, and an electric fan for cooling said electronic circuits and components, with said box-like casing (2) provided with a window (20) having a regular shape and placed in front of said electric fan in order to allow said electric fan to draw fresh air from the outside, said ventilation grid (1) being provided to protect said window (20) and characterized in that it comprises: a body (10) whose perimeter, shape and surface are at least sufficient to cover said window (20), with said body (10) formed by two lateral laths (11) mutually connected by an arc-shaped pantile-like wall (12), with its extrados facing outwards; an opening (13), made in the central area of said arc-shaped pantilelike wall (12); a plurality of fins (14), integral with said body (10), projecting outwards from said curved wall (12), disposed parallel to said lateral laths (11) and extending by the same length as said lateral laths, so as to pass through said opening (13), with each of said fins (14) shaped with a respective profile, in which the outer part (141) has an increased section with respect to the inner part (140), aimed, in conjunction with the adjacent fins (14), at hiding as much as possible the interposed portions of said curved wall (12) that is of said opening (13), from being seen from outside, with said profile being also suitable to allow, through said portions of said opening, a free passage of air from the outside to the inside of said box-like casing (2), without causing aerodynamic turbulences in the air flow itself. The grid according to claim 1 , characterized in that said lateral laths (11) have a symmetrical L-shaped section and in that the horizontal wings (11 A) of said "L" are directed towards the inside of said grid (1), to define the support abutments of said grid on said box-like casing (2). The grid according to claim 1 , characterized in that said plurality of fins (14) is formed by a straight central fin (14C), situated at the longitudinal centre plane of said curved, pantile-like wall (12) and orthogonally protruding

9 therefrom and by two sets of lateral fins (14L, 14R), arranged symmetrically at the sides of said central fin (14C), with each of said lateral fins (14L, 14R) having a dihedral profile, whose inner part (140) is parallel to said central fin (14C) and whose outer part (141) is inclined outwards.

4. The grid according to claim 1 or 3, characterized in that said central fin (14C) has a respective inner part (140) having a blade-like cross-section and the consecutive outer part (141) having an ogive cross-section, and in that in each of said dihedral lateral fins (14L, 14R), said inner part (140) has a bladelike cross-section while the outer part (141) has an ogive cross-section.

5. The grid according to claim 3 or 4, characterized in that the lateral fins (14L, 14R) of each of said two sets have said respective outer part (141) bent so as to be parallel to the outer part (141) of the adjacent lateral fins (14L, 14R).

6. The grid according to any one of the preceding claims, characterized in that said body (10) and said fins (14) are made of a monobloc of aluminium alloy, obtained by extrusion with a rectangular shaped, and in that said opening (13) in the curved, pantile-like wall (12) is obtained by subsequent machining with a machine tool.

7. The grid according to claim 2 or 5, characterized in that said opening (13) in the curved, pantile-like wall (12) has a rectangular shape, and is extended towards said lateral L-like laths (11) so as to be wider than the free space between the wings (11 A) thereof, and in that said wings (11 A) are partially reduced by the machining for the production of said opening (13).

8. The grid according to any one of the preceding claims, characterized in that an arched handle (4), removably connected to said body (10), is provided to be placed on top of said fins (14) and intended to facilitate the extraction of said box-like housing (2) of the electronic module (M) from a cabinet (3) in which it is recessed fitted.