WO2008078010A1

WO2008078010A1 - Method for shaping an annular or polygonal part of cellular foam

Info

Publication number: WO2008078010A1
Application number: PCT/FR2007/001727
Authority: WO
Inventors: Antonio Morgado Loureiro
Original assignee: Antonio Morgado Loureiro
Priority date: 2006-12-19
Filing date: 2007-10-19
Publication date: 2008-07-03
Also published as: EP2125308A1; FR2909917A1

Abstract

The invention relates to a shaping method that first comprises preparing a perform (3) by T-punch cutting in a plate or a strip of a cellular foam coil, then transforming said preform (3) so that it takes a shape corresponding to the final part (1), i.e. a polygonal or nearly cylindrical shape, depending on the case. The preform (3) has an outline that fits in a rectangular imprint, and it is cut for forming a slot (6) in the middle longitudinal portion thereof while keeping a portion of material at each end which is sufficient to be used as a hinge (7); it further comprises deep V-shaped notches (8) on its outer outline while also maintaining at said slot (6) a portion of material that is sufficient to be used as a hinge (9).

Description

Process for forming an annular or polygonal piece of cellular foam

The present invention relates to a method for shaping annular or polygonal parts which are made by means of a flexible material of the type - cellular foam, synthetic or not. These foam parts have multiple applications. They are commonly used to form a seal, for sealing and / or acoustic absorption, or for filling and / or wedging between two components.

This kind of piece is prepared by cutting, with a punch, from a sheet of foam or a strip drawn from a foam roll. These parts can also, depending on their destination, be totally or partially provided with an adhesive, and they are delivered as such to the user, in the automotive field, for example.

The cost of these parts is of course relatively modest, but they have many disadvantages, especially when it comes to parts whose shape is annular, polygonal, square or rectangular, for example.

Indeed, the manufacture of these parts generates a large amount of waste and their size is relatively important. These are parts that are not convenient to store and their transport is done with a weight / volume ratio that is not interesting.

To reduce the size of these parts, it is known to give them a first compact temporary form and then for their use, a definitive shape adapted to their function.

Documents US 3583711 and 5647255 show this type of part which, in a first step, is cut in a compact form so as to occupy the minimum surface area on the foam plate and which is then put into volume in the form of a polygonal or circular ring.

This piece is in fact carefully cut to form rectilinear sections, or curves as appropriate, which sections are connected by a portion of material and this portion of material acts as a hinge between two adjacent sections that can bend at an angle more or less important depending on the case.

These different hinges allow, when the time comes, to volume the piece, that is to say, to give it a devolved form, related to the application. But this setting in volume does not give a definitive piece which is stable.

Hinges, when deformed, introduce permanent tension between adjacent sections. The installation of a piece of this type requires the operator a certain dexterity and attention to keep the piece in the devolved form.

To counter this internal tension at the hinges and the tendency of the part to return to its original shape after its setting volume, complementary means are provided to assemble the ends of adjacent sections, at each hinge. This assembly can be mechanical with means of the type mortise and tenon.

In the field of air filters in the form of a cylindrical sleeve, it is also known to shape a small piece of space which is then placed in volume on a cylindrical support of metal or other.

This type of product is described in particular in document US Pat. No. 3,766,629 and, alternatively, in document FR 1387618. This variant has a part which is particularly compact after it has been shaped by cutting.

This document FR 1387618 shows a part which is cut with a rectangular contour and which is provided with a central longitudinal slot at the ends of which there remains a portion of material which acts as a hinge. Indeed, before use, the split piece is open and is returned and then strung on a perforated tubular support.

The end surfaces of the walls that constitute the filter are pressed against each other at these hinges to ensure maximum sealing at this level of said filter. As before, these pieces do not have a stable shape when used; moreover, for the parts described in the aforementioned documents US 3766629 and FR 1387618, a support is needed to maintain them in volume.

The present invention provides a method which solves, as previously, the problem of size of these annular or polygonal parts. But this method provides a solution to the problem of stability of the finished part; it allows the operator to have a piece to pose that corresponds to conventional parts, that is to say a piece whose form is stable, permanent, which does not require to be shaped simultaneously to the operation of pose. The present invention makes it possible to have a part which is both compact in its compact and stable configuration in its ready-to-install configuration, but this stable and permanent configuration for the installation results, on the one hand, from an arrangement original and, secondly, a particular intervention of the operator to turn said compact part into a piece ready to pose.

The invention thus makes it possible to achieve gains at all levels:

- at the manufacturing level, it reduces the amount of waste inherent in the shape of the room;

- at the transport level, it allows to densify the load; - At the level of the end user, it makes it possible to provide the operator with products that are practical for use, which also has the effect of improving the ergonomics of the workstation where the work is done. laying operation of these parts.

The shaping process makes it possible to produce parts in the form of an annular or polygonal frame, or with a more complex contour which comprises rectilinear, rounded parts, and even variable sections as in the case of the seals described in the aforementioned document US Pat. No. 5,447,255.

The method according to the invention consists, in a first step:

- Cutting a blank of the workpiece, said blank having an outline which is part of a small footprint, rectangular,

- Partially slicing said blank in its longitudinal median portion to form a slot and two branches which are connected at their ends by a portion of material acting as a hinge,

- to practice, on the outer contour of each branch, deep notches which have a shape in Vé, which notches are opened on the outside with an appropriate angle, and, in a second time:

- To develop the blank by separating the two branches and opening said slot, - then, to return said branches by a counter-rotating movement to invert the contours of said blank: the outer contour, with said deep notches, passes inside and the inner contour, arising from the middle cleft, passes to the outside, becoming the outer contour, which notches, conjugated with the arrangements of said ends of the branches, by their number, their position and their shape, automatically and permanently and permanently print the contour of said part.

Still according to the invention, the method consists in forming on each branch of the blank, notches whose depth is between 1/3 and 5/6 ^th of the thickness of said branches.

According to another embodiment of the invention, the method also consists, for a part which must have a final quasi-circular shape, in making shallow complementary incisions in the branches, starting from the central longitudinal slot, which complementary incisions are arranged. on the one hand, perpendicularly to said median slot and, on the other hand, between the notches, midway between them, said complementary incisions lying on the outer contour of said part after the flipping of said panels.

Still according to the invention, the depth of the complementary incisions is between ¹ A and 1/3 of the thickness of the branches of the blank.

The invention also relates to the products obtained by the method and in particular the blank of cellular foam cut from a plate or a strip of a roll, said plate or strip may comprise a face covered with a material of the adhesive kind. It also relates, and above all, the piece produced from the blank and whose shape derives from the implementation of the method of the invention and in particular the method of converting said blank into a final piece.

The invention also concerns, as a new industrial product, an annular piece serving as a joint between a loudspeaker and a panel such as, for example, a trim panel on a motor vehicle door, said part possibly comprising, on one of its faces, an adhesive that allows it to be glued to said panel before the installation of said speaker.

But the invention will be further detailed with the aid of the following description and the appended drawings, given as an indication, and in which:

FIG. 1 shows a conventional annular piece of foam type seal for loudspeaker; - Figure 2 shows, on a smaller scale, the parts of Figure 1 and in particular their footprint on a plate after cutting with a punch;

FIG. 3 shows a plate with imprints corresponding to the size of the blanks of parts which are produced according to the first phase of the method according to the invention;

FIG. 4 shows an exemplary blank of a part according to the invention, the cutting of which makes it possible, ultimately, to give a part which is similar to the part shown in FIG. 1;

FIG. 5 shows an example of the possible arrangement of the imprints of the blanks of FIG. 4 on a foam plate;

FIG. 6 illustrates the first operation of the process of transforming the blank into a finished part;

- Figure 7 shows the finished part obtained from the blank shown in Figure 4; - Figure 8 shows a blank portion which has multiple external notches and, in several places, internal incisions, to achieve, after turning, a piece which is almost cylindrical;

FIG. 9 shows the shape of a portion of the finished part obtained from the blank shown in FIG. 8; - Figures 10 to 13 show alternative embodiments of blanks and the parts obtained which are shaped frames: square, Figure 10, and rectangular, Figure 12;

FIGS. 14 to 17 show several embodiments of the ends of the blank; - Figures 18 to 23 show several forms of cutouts of the ends of the slot which extends in the middle longitudinal portion of the blank.

The part shown in FIG. 1 corresponds to a piece (1) in the form of an annular seal such as can be found, for example, on a door trim panel of a motor vehicle to effect the junction between said panel and a loud speaker.

This kind of part is made of cellular foam of the polyurethane type, polyethylene, EPDM ... etc. The piece is traditionally obtained from a plate (2) or a strip drawn from a cellular foam roll, by die cutting, on a suitable press.

The impression of several annular pieces (1) and their distribution on the plate (2) appears in FIG.

This traditional manufacturing process generates a large amount of foam waste. In addition, for this type of room that may have an adhesive on one of its faces, as is the case for speaker joints, the recycling of this waste is not without posing serious problems to because of the presence of this adhesive and the protective paper.

FIG. 3 immediately shows the advantage of the method according to the invention for producing pieces cut from a plate (2) identical to that of FIG. 2, that is to say a plate (2) which may comprise it also a side lined with adhesive with a protective paper. The method according to the invention makes it possible to limit the quantity of waste; the pieces (1) are no longer cut directly with their final shape but in a compact form; the piece is first of all a blank (3) which is part of a rectangular cut-out cavity, which makes it possible to eliminate the falls inherent in the conventional manufacturing method illustrated in FIG. 2. The detail of this form of blank 3 is in the form of an elongate body made of cellular foam and this body is split longitudinally in its median part, delimiting two branches (4). ) and (5).

The slot (6) longitudinal and median extends over a portion of the length of the blank (3), leaving a little material at each end to form hinges (7) whose role will appear later.

The length L of the blank (3) corresponds approximately to half the length of the circumference of the part (1) that one wants to obtain, that is to say to πD / 2 where D, is the outer diameter of said piece (1), as shown in Figure 1. The two branches (4) and (5) have regularly distributed, notches (8) which have a V-shaped open on the outside. These notches (8) are deep and extend to the level of the slot (6), leaving there also a little material which constitutes, in each of them, a hinge (9) whose role appears below.

The depth of the notches (8) is, for example, between 2/3 and 5/6 of the thickness of the branches (4) and (5). Each branch (4), (5), consists of segments, of which there are four in FIG. 4, and the length de of the facet (10) of each segment is a sub-multiple of the length of the inner circumference of the part (1), that is to say a sub-multiple of πd where d is the inside diameter of said part (1), as shown in FIG. 1. FIG. 5 shows, on a different scale, smaller, the imprints and the arrangement of the blanks (3) on a plate (2) of cellular foam.

The arrangement and the nesting of the blanks (3) on the plate make it possible to limit the waste; these waste correspond to the only contour of said plate and the notches (8), that is to say a derisory amount of waste compared to what can be found with the traditional cutting of parts (1) as shown in FIG. 2.

For ease of handling, transportation and delivery, the blanks (3) can be welded together with material bridges, whether foam and paper that protects the adhesive, as the case may be. The blanks (3) are in clusters and can be easily separated by the operator responsible for mounting them on site before the transformation and shaping operation.

The transformation operation which consists of passing the foam rod shown in FIG. 4, forming the blank (3), to an annular or polygonal shape which corresponds to the final part (1) shown in FIG. 7, appears in FIG. operation consists first of spreading the two branches (4) and (5) to open the blank (3) at its slot (6), then to turn on themselves these two branches (4) and (5) in a counter-rotating movement so as to pass the notches (8) from the outside of the blank (3) to the interior of the workpiece (1), as well as the facets (10) which are in contact -touche to delimit the internal contour of said part (1).

During this transformation operation, one passes from a stable part: the blank (3) whose contour is rectangular, to another stable part: the piece (1) definitive whose geometric shape is defined according to the destination. In the embodiment illustrated in FIGS. 4 to 7, the number of facets (10) is eight, which gives a polygonal appearance to the part (1).

It is also possible to make an elliptically shaped piece by playing on the angles of the notches (8) and on the cuts made at the ends of the blank (3). To obtain a part (1) quasi cylindrical, as shown in Figure 9, we can multiply the number of notches (8) and the number of facets (10).

The blank (3) which is partially shown in FIG. 8, comprises a larger number of facets (10), 16 for example.

It may also comprise, to approach even more of the cylindrical shape, the cutouts that appear, Figure 9, in the form of simple incisions (11) complementary made on the outer contour of the workpiece (1).

On the blank (3), these incisions (11) complementary are arranged on either side of the slot (6), from the latter; they are perpendicular to said slot (6) and extend in the limbs (4) and (5) to a shallow depth, the range, for example, between ¹ A and 1/3 of the thickness of said branches.

These modest incisions (11) complementary are to be taken into account for the determination of the length of the perimeter of the part (1).

FIG. 10 shows a finished piece (1) in the form of a square frame and this frame is obtained from the blank (3) which is represented in FIG. 11. This blank (3) comprises a slot (6) as previously FIGS. and 8 and two notches (8) which form a Vé whose opening angle is 90 °. The ends of the blank (3) are dihedral and the open angle of this dihedron is 180 ° + 90 °, 270 °.

When the blank (3) is set in volume by turning its branches (4) and (5) to become the part (1) shaped frame, the notches (8) are positioned inside and closed, as well as the dihedrons of the two ends, around the hinges (9) and (7) respectively.

FIG. 12 shows a finished piece (1) in the form of a rectangular frame and this frame is obtained from the blank which is shown in FIG. 13. Again, the notches (8) are in the shape of a Vé whose angle is 90 ° and the ends of the blank (3) are identical to those of the blank of Figure 11.

When setting volume, the notches (8) and the dihedral closes on the hinges (9) and (7), as before. The shape of the ends of the blank (3) may vary slightly, as shown in Figures 14 to 17.

Figures 14 and 15 show a dihedral end whose open angle (13) is of the order of 270 °, as indicated above. The tip of the dihedron encloses the end of the slot (6) and is the hinge (7) which is the junction between the two branches (4) and (5).

This dihedral can be in peak as represented figure 15 or be truncated as represented figure 16.

Its shape can also be more complex, as shown in Figure 17, with an end that is truncated in the form of a circular arc whose center is located on the point of fictitious intersection of the dihedral or even beyond.

These forms represented in FIGS. 16 and 17 condition the shape of the hinge (7); they make it possible to put the facets (10) in contact with one another and to improve the sealing of the internal surface of the finished piece (1). The shape of the hinges (7) can also be influenced by the shape of the end of the slot (6).

Figure 18 shows an end of the slot (6) which ends with a notch (14) in the form of a small cylinder.

Figure 19 shows a small cut (14) which is straight and perpendicular to the slot (6).

FIG. 20 shows a notch (14) in the form of a small half-cylinder open on the slot (6) whereas FIG. 21 shows this small half-cylinder open on the contrary opposite of said slot (6).

Figures 22 and 23 show a V-shaped end, which V e is open, respectively, opposite the slot (6) or towards said slot.

All these cuts (14) will condition the shape of the periphery of the piece (1) finished, at the two hinges (J), as required.

This shaping applies to any type of parts whose final shape is annular, polygonal or a combination of both, that is to say a square piece or other with corners arranged in an arc with a large radius.

Similarly, it is suitable for complex parts whose sections may vary in certain parts of the outline.

Claims

1 - A method of forming an annular or polygonal piece of cellular foam, characterized in that it consists, in a first step:

- Cutting a blank (3) of said piece, having a contour which is part of a footprint of small size, rectangular,

- partially slicing said blank (3) in its longitudinal central part to form a slot (6) and two branches (4, 5) which are connected at their ends by a portion of material acting as hinge (7),

- to practice, on the outer contour of each leg (4, 5), deep notches (8) which have a V-shaped shape, which notches (8) are open on the outside with an appropriate angle, and, in a second time:

- developing said blank (3) by separating the two branches (4, 5) and opening said slot (6), - then, to return said branches (4, 5) by a counter-rotating movement to invert the contours of said blank (3): the outer contour, with said notches (8), passes inside and the inner contour, resulting from said middle slot (6), passes to the outside, becoming the outer contour, which notches (8) , combined with the arrangements of said ends of the branches (4, 5), by their number, their position and their shape, automatically and permanently and permanently print the annular or polygonal contour of said part.

2- A method of forming a cellular foam part according to claim 1, characterized in that it consists in shaping, on each branch (4, 5) of the blank (3), notches (8) shaped Ve whose depth is between 1/3 and 5/6 ^th of the thickness of said branches (4, 5).

3 - A method of forming a cellular foam part according to any one of claims 1 or 2, characterized in that it consists, for parts which must have a final shape almost circular, to make incisions (11) shallow complements from the median slot (6), which incisions (11) are arranged, on the one hand, perpendicular to said median slot (6) and, on the other hand, between the notches (8), half -distance of the latter. 4 - A method of forming a cellular foam part according to claim 3, characterized in that it consists in making incisions (11) from the slot (6) whose depth is between the ¹ A and the 1/3 of the thickness of the branches (4, 5) of the blank (3). 5 - blank of polygonal piece made of cellular foam, characterized in that it is obtained by the method according to any one of claims 1 to 4.

6 - part of the type cellular foam, characterized in that it is obtained from a blank (3) according to claim 5, and in that it has been shaped by the method according to any one of Claims 1 to 4. 7 - Part according to Claim 6, of the type of annular seal made of cellular foam interposed between a loudspeaker and a panel, such as, for example, a trim panel on a motor vehicle door, characterized in that it comprises, on one of its faces, an adhesive which allows it to be stuck on said panel before the installation of said speaker.