Method of producing a part by decomposition into layers, said part having fluid transfer channels extending through the interlayers thereof

The present invention relates to a method for producing a part comprising a circulation of a medium, and a part obtained by the method.

[0002] In particular, the invention aims at solving problems arising in the provision of a channel ensuring the transfer of media (liquid or gaseous) through the part wall, i.e. transferring the medium from the inner channel to the outer surface (and vice versa). This invention is advantageously used in forms intended for the field of plastics processing (thermoforming, polystyrene injection), foundry (sand casting), hydraulics (filter production), mechanics (tooling), glassware, this list being unlimited.

In particular, the invention aims to replace and / or improve, in the tooling, the use of slit filters or micro-holes formed on the surface of the tooling, these micro-holes most often serving:

- as vents to facilitate the extraction of assisted or non-assisted factors;

- as diffusers of factors necessary in the process of the production under consideration. [0004] The problems of the prior art are solved by the invention, which involves the use of the Stratoconception ® method for use in the manufacture of a part and its built-in circulation of the medium.

[0005] The Stratoconception method is described in patents and patent applications FR 2 845 492, FR 2 673 302, WO 00/31599 and WO 00/31600.

[0006] The object of the invention is a new application that solves the above-mentioned problems of processes known in the art.

[0007] The invention will be better understood by the following description presented with reference to the accompanying figures of the drawings.

Figure 1 shows a part of the tooling seen from the side of the blank of the form of the element to be made, according to the first non-limiting embodiment of the invention,

Figure 2 - part of the tooling of figure 1, seen from the back side, Figure 3 - view of the fragmentation of the tooling of figure 1 restricted for purposes of explanation, with two planes (P1, P2) perpendicular to the mold opening plane and to the lamination direction,

Figures 4a and 4b - views defining the arrangement of the channels for carrying the medium, and detail G,

Figure 5 - cross-sectional view of the tooling of figures 4a, 4b, made at the level of the interlayer plane (Pi) and showing the layer (6i), the view according to the direction of the arrows AA,

Figures 6a and 6b - a three-dimensional view of the tooling according to the invention made with inter-layer planes having a flat surface, and detail H,

Figures 7a and 7b - a three-dimensional view of the tooling according to the invention made with inter-layer planes with a curved surface, and detail I,

Figure 8 - detail view of the interlayer plane (Pi) showing the structure of the channels by folding the layers (6i) and (6i + i) into one inter ground plane Pi,

Figure 9 - detail view of one of the media transfer channels made in the interlayer plane Pi according to the first embodiment,

Figure 10 - detail view of one of the media transfer channels made in the interlayer plane Pi according to a second variant,

Figure 11 - three-dimensional view of the obtained channels made in the interlayer plane Pi according to the second solution,

Figure 12 - detail view showing the third variant of the factor channels provided in the Pi interlayer layers,

Figure 13 - view of a detail of the instrumentation made according to the invention and provided with a supply or diffusion conductor with a rectangular section,

Figure 14 - view of a detail of the instrumentation made according to the invention and provided with a power or diffusion conductor with a circular cross-section,

Figure 15 - view of a detail of the instrumentation made according to the invention and provided with a supply or diffusion conductor of any cross-section,

Figures 16a, 16b, 16c - views showing the angle of inclination (α) relative to ^kand^this (Β).

[0008] It is described, by way of a non-limiting example of the application of the invention, to make channels for the removal or diffusion of a medium in the part of the tooling intended for the car, in connection with figures from to 16.

[0009] The invention can, of course, be applied to any part other than instrumentation containing channels for circulating the agent.

The invention is based on the use of a method called Stratoconception ® to be carried out, at the level of various interlayers (these inter plane layers may be flat or curved), channels (2) allowing the medium to pass through the tooling (1) and around the object during its formation (figs) .1 and fig.2).

[0011] Said tooling is formed from the back side 7 and the front side constituting the plane of opening of the tooling and comprising a molding cavity (9) for forming an object not shown. According to this method, the tooling (1); it is, in its conception, divided into layers (... 6, 6j + and ....), which, when assembled, form tooling (1) (fig.3). At the time of designing the tooling, a set of ducts (2) (hatched area in Figure 4) is predicted at the level of each interplanar plane around the mold cavity (9) (and opening therein) through the tooling.

[0012] These channels are thus closed and open at one end in the mold cavity (9) and at the other end on the back (7) so as to allow the medium to pass from one side to the other of the tooling or parts.

[0013] This set of ducts (2) is formed from a feed part (3) and from a diffusion part (4) joining a molding cavity (9) on one side and, on the other hand, a tool back side (7) (figure 4). To manage the flow of factors, the supply part (3) can have a depth (P'r) greater than or equal to the depth (Pr) of the diffusion part (4) (fig.5).

[0014] The use of "with curved surfaces" allows to eliminate problems with the play (Figure 6) and / or to always maintain the normal flow of the medium to the forming surface (Figure 7).

[0015] Channels (2) of the same plane between a sandwich (flat or curved surface) (Pi), made, in whole or in part, on one side of the layer (6j), are open towards said interlayer plane (Pi) during when the side opposite the next layer (6j + 1) (flat or curved) may comprise a complementary shape of the channels (2) (figure 8).

[0016] In the same interplanar plane, the separation of the supply part (3) from the diffusion part (4) is calculated by shifting by the value (d) from the profile (10) of the part (figure 9). Said profile is determined by calculating the intersection of the surface of the foundry cavity (9) with the interlayer plane (Pi). This value (d) may be subject to the law of changes depending on the needs of the circulation of the medium and allows changing the channel (2) depending on the profile (10) of the part at the level of each interlayer plane (Pi).

[0017] The interlayer layer is formed from channels (2) (the zone hatched in fig. 4) for the medium and the backrest zones (5) between the layers (6,) and (6_{and +}i), which may be located, in any case, in the diffusion part (figure 9) or in the supply part (fig.10). In this case, secondary support zones (11) may be provided in the supply part. These secondary support zones ensure the precision and stiffness of the stack of layers if the surface of the supply part is much larger than the surface of the diffusion part (Figure 10). In some cases, the stiffness of the tool may even need to be improved by providing a layer with a zipper as defined in patent applicant FR 2 834 803.

[0018] When the support zones (5) are in the supply part, it is formed of supply lines (12). This configuration defines the first variant (Figure 9). The power cables (12) are parallel to each other and are characterized by a width (l) and pitch (p) between two successive supply lines. The flow of the medium is then ensured by the diffusion part on the whole profile (10) of the molding cavity (fig, 9).

[0019] Similarly, in a second configuration variant, the diffusion part is provided with support zones and is formed of diffusion lines (13) (figure 10). The diffusion lines (13) can then be either parallel to each other or perpendicular to the forming surface, or inclined at an angle (β) with respect to the flow direction of the medium in the supply channel (fig.10), and are characterized by a width L and a pitch p between two consecutive diffusion lines (13). The obtained result on the tooling after the layers are deposited is a network of diffusers in the form of gaps (8) distributed over the entire forming surface. Seen from the rear, the tooling has a wide gap at the level of each interplanar plane formed by selecting the supply portion.

[0020] A third variant of the construction has also been proposed (figure 12). It concerns the execution of channels in parts or fragments of slender parts; their slenderness is such that the diffusion part with a thickness (d) is predominant. Well, the supply part takes the form of a normal cable, in which no backrest zone (5) is built-in. These support zones are therefore necessarily incorporated into the diffusion part, which is then formed from diffusion lines (13), which can be parallel to each other, perpendicular to the forming surface or inclined at an angle (β) with respect to the flow direction of the medium in the feed channel . The use of angle (β) is advantageous because it allows to optimize and homogenize the factor diffusion.

[0021] The geometry of the channels (2), i.e. (width (l) and stroke (p) between two successive wires (12) or (13), and constant or variable thickness (es) are parameterized depending on the flow rate of the medium The "p" travel is defined as the axial spacing between the two conductors (12) in the case of a parallel conductor system (Figure 9) and as the length of the profile section (10) separating the two conductors (13) ) perpendicular or two wires inclined at an angle (β) (figure 10, fig.12).

[0022] The geometry of the wires ((12) or (13) or 14)) is determined by their depth (Pr) and their section (14) along a plane perpendicular to the interplanar plane, which may be straight (Figure 13), with a circular cross-section ( FIG. 14) or any (FIG. 15).

[0023] The angle (β) is parameterized and computed numerically. It can vary over the entire length of the part so as to allow minimizing pressure losses (mainly for the third variant).

[0024] This angle (β) is determined in the plane of the layer, but it can also be supplemented by a second angle (α) defined in its thickness (figure 16).

[0025] All of these parameters allow, during tool design, to optimize and homogenize the flow of the medium over the entire forming surface so as to provide the best tooling parameters so that it can produce parts with optimized quality and / or with a minimum cycle time. Software dedicated to the Stratoconception® method perform mathematically and digital distribution into layers, create the above mentioned channels transferring factors and optimize their parameters, using the right algorithm.