FR3087706A1 - PROCESS FOR PRODUCING A TRIM ELEMENT WITH A DECORATIVE SURFACE - Google Patents

Abstract

The invention relates to a method of producing a decorative surface of a trim element of a vehicle, the decorative surface comprising a pattern formed of a plurality of adjacent strips, the method comprising the following steps: - superposition of a plurality of layers (16) of material in a main direction (Z) to form a stack (18), - Cutting the stack (18) along at least one cutting surface, each layer (16) being intended to form a strip of the pattern. The cutting surface defines a cutting angle (α) with respect to a plane defined by the main direction (Z) and a cutting direction (X), the cutting angle (α) being non-zero at least partially during l 'cutting step. The cutting angle (α) is calculated as a function of a width of the bands, measured in a transverse direction of the pattern.

Description

The present invention relates to a method of producing a decorative surface of a vehicle upholstery element, the decorative surface comprising a pattern formed from a plurality of adjacent strips. , the method comprising the following steps: - superposition of a plurality of layers of material in a main direction to form a stack of layers, - cutting of the stack of layers according to at least one cutting surface, each layer of material being intended forming a strip of the pattern of the decorative surface.

WO 2010136348 describes a production method of the aforementioned type.

The cutting surface follows the desired shape for the packing element.

However, this method does not make it possible to obtain a trim element comprising a decorative surface in which the width of the set of bands is variable.

Indeed, the strips of the decorative surface here have the width of the layer of the corresponding stack.

An aim of the invention is therefore to provide a production method suitable for producing trim elements having a decorative surface comprising a pattern of a plurality of adjacent bands, the width of all the bands being variable.

To this end, the invention relates to a production method of the aforementioned type, in which the cutting surface defines a cutting angle with respect to a plane defined by the main direction and a cutting direction, the cutting angle being non-zero at least partially during the cutting step, the method comprising a step of calculating the cutting angle as a function of a width of the strips of the pattern, measured in a transverse direction of the pattern.

By varying the angle of cut according to the width of the stripes of the desired pattern, the dimension of the cutout of the visible layer varies along the direction of cut so as to allow stripes of the pattern having a varying width to be formed. of said cutout.

The production process can also have one or more of the characteristics below, considered individually or according to all the technically possible combinations: - the cutting angle is equal to the arc cosine of the ratio of a height of the layers across the width of the strips, - each layer is formed in a woody or polymer or mineral material, 2 - the cutting step is carried out with a blade moving in the direction of cutting, the blade forming with the plane defined by the main direction and the cutting direction an angle equal to the cutting angle, - before the step of calculating the cutting angle, the method comprises the following steps: - modeling of the decorative surface of the element of filling to be manufactured in three dimensions to form a three-dimensional model, and - two-dimensional simulation of a flattened model of the three-dimensional model, of the bands made of a material of the respective corresponding layer and aya nt dimensions according to the flattened model being adapted to obtain the decorative surface of the lining element by deformation of the respective material. - the method comprises a step of defining a generating curve corresponding to a median curve of the decorative surface of the lining element, - the definition of the generating curve is carried out on the model laid flat, the generating curve being the median curve of the flattened model, the width of the bands preferably being measured on the flattened model perpendicular to the generating curve, 20 - the method comprises a step of cutting each layer of material from a block of material, so that each layer of material extends along the generating curve, - the method comprises a step of assembling the strips on a support to form the decorative surface of the lining element, and / or - the stack is cut according to at least two cutting surfaces, two consecutive cutting surfaces being spaced by a distance of between 0.2 millimeters and 2 millimeters, preferably between 0.5 millimeters and 0.8 millimeters.

Other characteristics and advantages of the invention will emerge from the detailed description which is given below, by way of indication and in no way limiting, with reference to the appended figures, among which: FIG. 1 is a perspective view of 'a first embodiment of a decorative surface of a trim element, - figure 2 is a schematic view of the flattened model of the decorative surface of figure 1, - figure 3 is a curve showing the variation of the width of the strips along the generating curve, 3 - figure 4 is a schematic perspective view of the step of cutting a stack according to a method of the invention to obtain the decorative surface of figure 1 - Figure 5 is a schematic block view of the steps of a production method according to one embodiment of the invention, 5 - Figure 6 is a perspective view of a second embodiment of a surface decorative element of a trim element, - figure 7 is a schematic view of the flattened model of the decorative surface of figure 6, and - figure 8 is a schematic perspective view of the step of cutting a stack according to the method of invention to obtain the decorative surface of Figure 6.

The invention relates to a method for producing a decorative surface 12 of a trim element of a vehicle, a first example of which is shown in FIG. 1.

The decorative surface 12 comprises a pattern formed of a plurality of adjacent bands 14.

Each strip 14 is made from a given material, for example from a respective woody or polymer or mineral material.

Each strip 14 is translucent or opaque.

Each strip 14 has a respective apparent width 13D measured in a local transverse direction T of the pattern.

The transverse direction T is, for example, defined locally at a point of the strip as the perpendicular to a so-called longitudinal direction L corresponding to the local tangent of said strip at this point.

The apparent width 130 of each strip 14 is variable along the strip.

The variation in the apparent width 130 of each strip 14 is similar for all of the strips along the longitudinal direction L, i.e. the ratio between the apparent width I3D of a given strip and the apparent width of another strip taken along the same transverse direction T is constant for any point of the given strip.

A particular embodiment of the production method is shown in FIG. 5.

The method comprises the following steps: - superposition 110 of a plurality of layers 16 of material to form a stack 18 of layers, and - cutting 120 of the stack 18 of layers 16 according to at least one cutting surface, each layer 16 of material being intended to form a strip 14 of the pattern of the decorative surface 12.

4 Each layer of material 16 is, for example, previously cut from a block of material during a preliminary cutting step 100.

Each layer of material 16 extends along the same main curve 26, that is to say that the general curvature of the layer 16 follows the main curve 26.

Each layer of material 16 is invariable in a direction called extension Y.

Each layer 16 has a constant dimension taken perpendicular to the main curve 26 along said main curve 26, said dimension being called the height of the layer 16.

The superposition of the plurality of layers 16 of material is carried out in a main direction Z.

When the main curve 26 is a straight line as shown in FIG. 4, the height of the layer in the stack extends in the main direction Z.

The main direction Z is, for example, the vertical direction defined by gravity.

The stack 18 of layers is, for example, held by two pieces on either side of said stack, to form a vise 19.

The cutting surface defines a cutting angle a with respect to a plane defined by the main direction Z and a cutting direction X.

The cutting direction X, the direction of extension Y and the main direction Z are perpendicular to each other in pairs.

More particularly, the cutting surface has a cutting angle varying along the cutting direction X and constant along the main direction Z.

The cutting step 120 is carried out with a blade 20 moving in the cutting direction X as can be seen in FIG. 4.

The blade forms with the plane defined by the main direction and the cutting direction an angle equal to the cutting angle.

The blade 20 passes through the entire stack 18.

In particular, the blade 20 passes through the stack 18 right through in the main direction Z.

The blade extends mainly in a direction being one made up of the Y and main Z extension directions.

The cutting angle a is at least partially non-zero during the cutting step 120 and is calculated as a function of a width of the strips 14 of the pattern.

The cutting angle a varies, for example, during the cutting step 120.

The cutting angle varies as the blade moves in the X cutting direction.

The cutting surface then has, for example, undulations.

5 This makes it possible in particular to obtain a pattern with a strip 14 whose respective apparent width 13D is variable in the longitudinal direction L.

In a particular embodiment, the stack is cut along at least two cutting surfaces.

Each strip 14 of the pattern of the decorative surface 12 is thus cut between two consecutive cutting surfaces in each layer 16 of material.

The cutting surfaces are identical by translation in the direction of extension Y.

Two consecutive cutting surfaces are spaced a distance between 0.2 millimeters and 2 millimeters (mm), preferably between 0.5 millimeters and 0.8 millimeters (mm).

This in particular makes it possible to have thin bands, which in particular makes it possible to deform them slightly to allow them to take a final shape.

Following the cutting step, the strips are assembled during an assembly step 130 of the strips on a support to form the decorative surface 12 of the trim element 10.

The assembly step 130 consists, for example, in gluing each strip 14 on a flexible woven or non-woven support, for example textile, depending on its position in the pattern.

The support is previously or successively fixed to the rest of the lining element on a surface to be decorated, so that the strips form an outer surface of the lining element then forming the decorative surface of said lining element.

The bands are, for example, sufficiently deformable to allow the support to adapt to the surface to be decorated of the lining element.

Alternatively, the support corresponds directly to a surface to be decorated of the lining element.

An example of a method for calculating the cutting angle α is described below.

In a modeling step 200, the decorative surface 12 of the trim element to be manufactured is modeled in three dimensions to form a three-dimensional model, as shown in FIG. 1.

Then, a flattened model 22 shown in FIG. 2 of the three-dimensional model is simulated in two dimensions during a simulation step 210.

Each strip 14 of the decorative surface 12 is fitted to the flattened pattern 22 such that each strip made of a material of the respective corresponding strip 35 and having dimensions according to the flattened pattern is adapted to obtain the strip. of the decorative surface of the trim element by deformation of the respective material.

The flattened pattern 22 corresponds, for example, to the result which would be obtained by flattening the decorative surface 12 in a press in a given direction, more particularly perpendicular to the longitudinal L and transverse T directions.

The flattened model 22 is, for example, obtained by a digital calculation of the evolute of the three-dimensional model, for example in the median plane orthogonal to the surface of the three-dimensional model.

The flattened model 22 makes it possible in particular to calculate or define various parameters of the decorative surface, such as a generating curve or a width of or at least one strip (s) as described below.

A generator curve 24 is defined during a step of defining said generator curve 220.

The generating curve corresponds to a median curve of the decorative surface 15 12 of the trim element.

More particularly, the definition of the generating curve is carried out on the flattened model 22, the generating curve 24 being the median curve of the flattened model 22 as visible in FIG. 2.

The generating curve 24 makes it possible in particular to determine the general curvature 20 of the decorative surface 12 of the trim element.

During the cutting step 100, each layer 16 is, for example, cut such that the main curve 26 follows the generating curve.

Furthermore, the width I; at least one strip 14 and / or width 1 m of all the strips 14 is measured on the flattened model 22 during a step 25 of measuring said width 230.

The width of all the bands lm and / or at least one of the bands I is measured perpendicular to the generating curve 24.

It is considered, for example, that the apparent width 13D of a strip is substantially equal to the width I, at the corresponding point on the model 22 flattened.

The stretches in the longitudinal L and transverse T directions are locally negligible here.

Said measuring step 230 is carried out at several points along the generator curve 24, for example, at regular intervals along the generator curve 24.

The pitch is, for example, chosen to have an evolution of the width I, or of the width lm less than or equal to 5% between each measurement.

7 The cutting angle a is then calculated during a step of calculating said angle 240.

The cutting angle a is equal to the arc cosine of the ratio of the height of the stack 18 to the width hot of all the strips of the model flattened out.

Alternatively, the cut angle a is equal to the arc cosine of the ratio of the height of a given layer 16 of the stack 18 to the width h of the corresponding strip of the flattened model 22.

Each of the ratios is calculated for the same point of the generator curve, that is to say that the width I, of a band or the width hot of all the bands of the flattened model 22 is measured at point of generator curve 24 corresponding to the point of main curve 26 at which the height of the corresponding layer 16 of stack 18 or the height of stack 18 is measured.

By varying the cut angle α, the width of each of the cut strips also vary.

This then makes it possible to obtain a decorative surface in which the bands have a variable width.

A second example of a decorative surface 1012 that can be produced by said method is shown in FIG. 6.

For this second example, the references for similar or identical elements are similar to the first example of Figures 1 to 4, each reference being incremented by 1000.

Only the elements by which this second example differs from the first will be described below.

As before, a flattened pattern 1022 is simulated so that the bands made of the given material and having dimensions according to the flattened pattern 1022 are adapted to form the bands 1014 of the decorative surface 1012.

The generator curve 1024 defined as previously is here a non-straight curve.

The width of each strip of the flattened model is measured perpendicular to said generator curve 1024, the cut angle being measured as a function of said width.

To achieve the decorative surface, each layer 1016 of material intended to form the stack 1018 is previously cut so as to extend along a curve 1026 extending along the generating curve 1024 and having a constant height along the curve 1026. .

Then the stack 1018 is cut as described above.

8 The fact that the generating curve 1024 may not be a straight line makes it possible in particular to produce decorative surfaces having various shapes.

The method of the invention makes it possible to obtain a great variability in the different possibilities of decorative surface produced, in particular by varying the angle.

Claims (10)

CLAIMS 1.- A method of making a decorative surface (12) of a vehicle trim element, the decorative surface (12) comprising a pattern formed from a plurality of adjacent strips (14), the method comprising the following steps: - superposition (110) of a plurality of layers (16) of material in a main direction (Z) to form a stack (18) of layers, - cutting (120) of the stack (18) of layers according to at least one cutting surface, each layer (16) of material being intended to form a strip (14) of the pattern of the decorative surface, characterized in that the cutting surface defines a cutting angle (a) with respect to a plane defined by the main direction (Z) and a cutting direction (X), the cutting angle (a) being non-zero at least partially during the cutting step (120), the method comprising a calculation step ( 240) of the cutting angle (a) as a function of a width of the strips (14) of the pattern, measured in a direction tr ansversale (T) of the pattern. 2. A method according to claim 1, wherein the cutting angle (a) is equal to the arc cosine of the ratio of a height of the layers (16) to the width of the strips (14). 3. A method according to claim 1 or 2, wherein each layer (16) is formed in a woody or polymeric or mineral material. 4. A method according to any one of claims 1 to 3, wherein the cutting step is carried out with a blade (20) moving in the cutting direction (X), the blade (20) forming with the plane defined by the main direction (Z) and the cutting direction (X) an angle equal to the cutting angle (a). 5.- Method according to any one of claims 1 to 4, wherein, before the step of calculating (240) of the cutting angle (a), the method comprises the following steps: - modeling (200) of the decorative surface (12) of the trim element (10) to be manufactured in three dimensions to form a three-dimensional model, and - two-dimensional simulation (210) of a flattened model (22) of the three-dimensional model, 10 strips made of a material of the respective corresponding layer (16) and having dimensions according to the flattened pattern (22) being adapted to obtain the decorative surface (12) of the lining element by deformation of the respective material. 5 6. A method according to any one of claims 1 to 5, comprising a step of defining a generating curve (24) corresponding to a median curve of the decorative surface (12) of the trim element (10). 10 7.- Method according to claims 5 and 6, wherein the definition of the generator curve (24) is performed on the flattened model (22), the generator curve (24) being the median curve of the flattened model ( 22), the width of the bands (14) being preferably measured on the model laid flat (22) perpendicular to the generating curve (24). 15 8.- The method of claim 7, comprising a cutting step (100) of each layer (16) of material in a block of material, so that each layer (16) of material extends along the generating curve. (24). 20 9. A method according to any one of claims 1 to 8, comprising a step of assembling (130) the strips (14) on a support to form the decorative surface (12) of the trim element (10). 10. A method according to any one of claims 1 to 9, wherein the stack 25 (18) is cut along at least two cutting surfaces, two consecutive cutting surfaces being spaced by a distance of between 0.2 millimeters. and 2 millimeters (mm), preferably between 0.5 millimeters and 0.8 millimeters (mm).