Patent Description:
More specifically, the invention according to a first aspect concerns a method for manufacturing first and second trim parts of vehicles, the first trim part having a first thickness and the second trim part having a second thickness different from the first thickness.

Indeed, car manufacturers usually propose, for the same type of car, regular trim parts and premium trim parts, with different coverings or finishes. The regular trim part for example comprises a NFPP layer (Natural Fiber Poly Propylene), covered by a thin decorated layer. The premium trim part comprises a foam layer between the decoration layer and the NFPP layer.

The decoration layer defines the visible surface, or A-surface, while the NFPP layer defines the non-visible surface, or B-surface. The regular and premium trim parts must be integrated in the same interior equipment. They must fit in the interior equipment, with no visible gap between the trim part and the surrounding parts.

It is possible to produce the first and second trim parts in different forming moulds. However, it is necessary in this case to buy two differents moulds, and the investment cost as a consequence is high.

<CIT> discloses an assembly with a forming mould adapted for manufacturing different trim parts, with different thicknesses. <CIT> discloses a method for manufacturing trim parts of an automobile.

The aim of the invention is thus proposing a method according to which the same mould can be used for manufacturing different trim parts having different thicknesses, and especially used for manufacturing a first trim part that has a compressible layer such as a foam layer, and a second trim part that does not have the compressible layer.

According to the invention, the method is as defined in the claim <NUM>.

Since the front and back inserts final positions can be adjusted by changing the settings of the mould, trim parts having different thicknesses can be formed in the same mould.

Moreover, and as explained in a more detailed manner below, the method allows producing in the same mould a first trim part with a foam layer and a second trim part without a foam layer. The front insert final position is adjusted taking into account the final expansion of the compressible layer, for the first trim part with a compressible layer. The back insert final position is adjusted as a function of the thickness of the trim part.

The method of the invention may include as well the features defined in the depending claims <NUM> to <NUM>.

According to a second aspect, the invention is directed to an assembly for manufacturing first and second trim parts of vehicles, the first trim part having a first thickness and the second trim part having a second thickness different from the first thickness, the assembly being as defined in the claim <NUM>.

The assembly of the invention may include as well the features of the depending claims <NUM> to <NUM>.

Other features and advantages of the invention will become apparent from the following detailed description of a non-limitative embodiment, made in respect of the following figures:.

<FIG> shows a cross section of an interior equipment <NUM> of a vehicle. The interior equipment is for example a door panel, a dashboard or any other equipment. The vehicle is typically an automobile or a truck.

The interior equipment shown on the left side of <FIG> comprises a first trim part <NUM>, and another part <NUM> to which the first trim part <NUM> is secured, for example by mean of one or several clips <NUM>, welding points or any suitable fixing means.

The first trim part <NUM> comprises a non-compressible layer <NUM>, and a compressible layer <NUM>. The compressible layer <NUM> is typically covered by a decorative layer <NUM>. The first trim part may also include one or several other layers. The first trim part has a first thickness.

The non-compressible layer <NUM> is for example a NFPP layer (Natural Fiber Poly Propylene). In another embodiment, the non-compressible layer is in a plastic material, or in any other material. Non compressible layer is understood here as meaning rigid or semi-rigid material which may be formed, with in some case a slight thickness reduction, during a forming operation but which do not expand after the forming operation.

The compressible layer <NUM> is typically a foam layer or a 3D textile layer.

The first trim part <NUM> comprises a central area <NUM>, where the non-compressible layer <NUM> is covered by the compressible layer <NUM>, and a surrounding area <NUM> , where the non-compressible layer <NUM> is not covered by the compressible layer <NUM>.

The other part <NUM> is fixed directly to the surrounding area <NUM>. As shown on the <FIG>, the surrounding area <NUM> is hidden behind the other part <NUM>. Most of the central area <NUM> is not located behind the other part <NUM> and is visible.

More precisely, the clips <NUM> are directly connected to the surrounding area <NUM>.

The other part <NUM> has an edge <NUM>, which bears against the decorative layer <NUM>. There is no gap between the decorative layer <NUM> and the edge <NUM>.

The decorative layer <NUM> defines the visible side of the trim part (A-surface) and the non-compressible layer <NUM> defines the non-visible side of the trim part (B-surface).

The <FIG> shows on the right side the same interior equipment <NUM>, equipped with a second trim part <NUM>. The second trim part <NUM> does not comprise a compressible layer. It has a second thickness, which is lower than the first thickness.

The second trim part comprises a non-compressible layer <NUM>. Typically, it comprises a decorative layer <NUM>, covering the non-compressible layer <NUM>. The non-compressible layer <NUM> is a NFPP layer, or a plastic layer, or is in any other adapted material.

Typically, in the surrounding area <NUM> of the second trim part <NUM>, the decorative layer <NUM> does not cover the non-compressible layer <NUM>.

Again, the other part <NUM> is fixed directly to the surrounding area <NUM>. The surrounding area <NUM> is hidden behind the other part <NUM>, whereas the greatest part of the central area <NUM> is not located behind the other part <NUM>.

The clips <NUM> are connected to the surrounding area <NUM>.

The edge <NUM> bears against the decorative layer <NUM>, with no gap between the decorative layer <NUM> and the edge <NUM>.

The A-surfaces of the first and second trim parts <NUM>, <NUM> are exactly at the same position, such that there is no gap, even though the first and second trim parts <NUM>, <NUM> do not have the same thickness. The surrounding areas <NUM> of the first and second trim parts, or at least the zones of the surrounding areas to which the other part <NUM> is fixed, are at the same positions. In other words, in the first and in the second trim parts <NUM>, <NUM>, the A-surfaces have exactly the same position with respect to the zones of the non-compressible layer <NUM>, <NUM> to which the other part <NUM> is fixed.

In the invention, the first and second trim parts <NUM>, <NUM> are manufactured using the assembly <NUM> depicted on the <FIG>.

The front tool <NUM> has a front fixed part <NUM> and a front movable insert <NUM> movable with respect to the front fixed part <NUM> along a main direction.

The back tool <NUM> has a back fixed part <NUM> and a back movable insert <NUM> movable with respect to the back fixed part <NUM> along the main direction.

The front fixed part <NUM> and the front insert <NUM> are mounted to a front frame <NUM>. The front fixed part <NUM> is rigidly secured to the front frame <NUM>. The front tool <NUM> includes an actuator <NUM>, for example a cylinder, connecting the front insert <NUM> to the front frame <NUM>.

The back fixed part <NUM> and the back insert <NUM> are mounted as well to a back frame <NUM>. The back fixed part <NUM> is rigidly secured to the back frame <NUM>. The back tool <NUM> includes an actuator <NUM>, for example a cylinder, or a spring, connecting the back insert <NUM> to the back frame <NUM>.

The front and back tools <NUM>, <NUM> are typically moved with respect to one another along the main direction to open or close the mould <NUM>.

The front and back fixed parts <NUM>, <NUM> form between them the surrounding area <NUM> of the first and second trim parts <NUM>, <NUM>. The front and back inserts <NUM>, <NUM> form between them the central area <NUM> of the first and second trim parts <NUM>, <NUM>.

The device <NUM> for introducing the first or second trim parts <NUM>, <NUM> in the forming mould <NUM> is typically a movable frame, equipped with means for clamping the first or second trim parts <NUM>, <NUM>.

The assembly <NUM> further includes front and back clamps <NUM>, <NUM> for clamping the first or second trim parts <NUM>, <NUM> after it is introduced into the mould <NUM>. The front clamp <NUM> is mounted on the front tool <NUM> and is moved with the front tool. It is for example connected to the front frame by an actuator <NUM>, for example a cylinder, so that its position along the main direction with respect to the front frame is adjustable selectively. The back clamp <NUM> is mounted on the back tool <NUM>. It is for example connected to the back frame <NUM> by an actuator <NUM>, for example a cylinder, so that its position along the main direction with respect to the back frame is adjustable.

When the mould <NUM> is closed, the front insert <NUM> occupies a final front position, and the back insert <NUM> occupies a final back position, the front and back inserts <NUM>, <NUM> defining a gap <NUM> between them (<FIG>).

The device <NUM> allows adjusting the followings settings of the mould <NUM>: the final front position of the front insert <NUM> with respect to the front fixed part <NUM>, and the gap <NUM> between the front and back insert <NUM>, <NUM>. More precisely, the device <NUM> allows adjusting the height of the gap <NUM>, taken along the main direction.

As will be explained below, the position of the front insert <NUM> remains unchanged with respect to the front fixed part <NUM> when the mould <NUM> closes. In other words, the front fixed part <NUM> and the front insert <NUM> are moved as one piece. The device <NUM> in this case comprises a control device <NUM>, controlling the actuator <NUM> in order to position the front insert <NUM> at a selected position with respect to the front fixed part <NUM>.

On the other hand, the mould <NUM> is arranged such that, when the mould closes by moving the front and back tools <NUM>, <NUM> toward one another, the central area <NUM> of the first or second trim part <NUM>, <NUM> is first pressed by the front insert <NUM> against the back insert <NUM>, the peripheral area of the first or second trim part <NUM>, <NUM> being not pressed by the front fixed part <NUM> against the back fixed part <NUM> at this stage.

When the front and back tools <NUM>, <NUM> are further moved toward one another, the back insert <NUM> is moved with the front insert <NUM> with respect to the back fixed part <NUM> along the main direction, until the peripheral area of the first or second trim part <NUM>, <NUM> is pressed by the front fixed part <NUM> against the back fixed part <NUM>.

The gap <NUM> is controlled for example by adjusting the height of a spacer <NUM>, attached to the front or to the back insert <NUM>, <NUM>, and extending between the front and back insert <NUM>, <NUM> (<FIG>). The height of the spacer <NUM> is controlled by the device <NUM>.

The first values of the settings are chosen such that, when the first trim part <NUM> is inside the mould and when the mould <NUM> is closed (situation of the <FIG>, left side), the front insert <NUM> has a first front final position along the main direction with respect to the front fixed part <NUM> and the back insert <NUM> has a first back final position along the main direction with respect to the back fixed part <NUM>.

The second values of the settings are chosen such that, when the second trim part <NUM> is inside the mould <NUM> and when the mould <NUM> is closed, the front insert <NUM> has a second front final position along the main direction with respect to the front fixed part <NUM> different from the first front final position, and the back insert <NUM> has a second back final <NUM> position along the main direction with respect to the back fixed part <NUM>, different from the first back final position.

To take into account that the first trim part <NUM> has a non-compressible layer <NUM> toward the back tool <NUM> and a compressible layer <NUM> toward the front tool <NUM>, the second trim part <NUM> having no compressible layer, the second front final position is shifted away from the back tool <NUM> along the main direction with respect to the first front final position by a quantity ΔA (<FIG>), chosen as indicated below.

As shown on the <FIG>, the compressible layer <NUM> is compressed when the mould <NUM> is in its closed position. When the first trim part <NUM> is outside of the mould <NUM>, the compressible layer <NUM> expands, toward the A-surface. The thickness of the compressible layer <NUM>, and of the central part <NUM> of the first trim part <NUM>, increases by a quantity Δth. The order of magnitude of Δth is frequently <NUM>. ΔA is chosen substantially equal to Δth.

The surrounding areas <NUM> of the first and second trim parts <NUM> and <NUM> are at the same final position when the mould <NUM> is closed.

Because of the shift of ΔA in the final position of the front insert, the A-surface of the second trim part <NUM> is at the same position with respect to the surrounding area <NUM> as the A-surface of the first trim part <NUM>, after the expansion (<FIG>).

The second back final position is shifted toward the front tool along the main direction with respect to the first back final position, by a quantity ΔB. The quantity ΔB is chosen according to the following equation:
ΔB - ΔA = T1 - T2, where T2 is the second thickness and T1 is the thickness of the first trim part in a compressed state corresponding to the closed position of the mould.

The non-compressible layers <NUM>, <NUM> of the first and second inserts <NUM>, <NUM>, as a consequence, have the same physical properties: density, weight per area. This point is especially important when the non-compressible layers <NUM>, <NUM> are made of NFPP or other similar materials.

The manufacturing process using the assembly above will now be described, with respect to <FIG> and <FIG>.

The manufacturing process will be described for a case where the first and second trim parts <NUM>, <NUM> described above have to be produced.

Initially, the forming mould <NUM> is in its open position, as shown on <FIG>.

The manufacturing method comprises the following steps:.

The first trim part <NUM> is laid down on the back clamping frame <NUM> by the device <NUM>. The first trim part <NUM> is initially flat, as shown on the <FIG>. The first trim part is oriented such that the compressible layer <NUM> faces the front tool <NUM>, and the non-compressible layer <NUM> faces the back tool <NUM>.

Then the front and back tools <NUM>, <NUM> are moved toward one another, for closing the mould. In the example shown on the figures, the front tool <NUM> is moved along the main direction toward the back tool <NUM>, the back tool being fixed. In other embodiments, the front tool is fixed and the back tool moves along the main direction, or both the front and back tools move along the main direction.

During the travel of the front and back tools <NUM>, <NUM> toward one another, the front insert <NUM> remains at the same position with regard to the front fixed part <NUM>. The front insert <NUM> and the front fixed part <NUM> are moved as one piece.

The front clamping frame <NUM> remains at the same position with regard to the front fixed part <NUM> as well. It is moved as one piece with the front insert <NUM> and the front fixed part <NUM>.

During a first part of the travel (<FIG>), the back clamping frame <NUM> and the back insert <NUM> remain at the same position with respect to the back fixed part <NUM>.

The first part of the travel ends when the first trim part <NUM> is clamped between the front and back clamping frame <NUM>, <NUM>.

During a second part of the travel (<FIG>), the back insert <NUM> remain at the same position with respect to the back fixed part <NUM>. The back clamping frame <NUM> moves with the front clamping frame <NUM> along the main direction, toward the back tool <NUM>. The actuator <NUM> is passive during the second part of the travel. It is driven by the pressure exerted by the front clamping frame <NUM> on the back clamping frame <NUM>.

The second part of the travel ends when the central area <NUM> of the first trim part <NUM> is pressed between the front and back inserts <NUM>, <NUM>.

During a third part of the travel (<FIG>), the back insert <NUM> moves with the front insert <NUM> with respect to the back fixed part <NUM> along the main direction toward the back tool <NUM>. The actuator <NUM> is passive during the third part of the travel. It is driven by the pressure exerted by the front insert <NUM> on the back insert <NUM>.

The back clamping frame <NUM> moves along with the front clamping frame <NUM> along the main direction, toward the back tool <NUM>. The actuator <NUM> is passive during the third part of the travel. It is driven by the pressure exerted by the front clamping frame <NUM> on the back clamping frame <NUM>.

The third part of the travel ends when the surrounding area <NUM> of the first trim part <NUM> is pressed between the front and back fixed parts <NUM>, <NUM>.

The mould <NUM> is then opened, and the formed first trim part <NUM> is removed from the mould, typically using the device <NUM>. The back clamp <NUM> and the back insert <NUM> are brought back to their initial position by the actuators <NUM> and <NUM>, respectively. The front clamping frame <NUM> is brought back to its initial position by the actuators <NUM>.

Typically, other trim parts, similar to the first trim part <NUM>, are manufactured as described above, before the settings of the mould are changed.

The settings of the forming mould <NUM> are then adjusted to the second values.

The front insert <NUM> is moved by mean of the actuator <NUM> with respect to the front fixed part <NUM>. If necessary, the position of the front clamping frame <NUM> is adjusted with respect to the front fixed part <NUM>, by mean of the actuator <NUM>.

The height of the spacer <NUM> is modified.

Then the second trim part <NUM> is introduced in the forming mould <NUM>, and laid down on the back clamping frame <NUM> by the device <NUM>. The second trim part <NUM> is initially flat. The second trim part <NUM> is oriented such that the decorative layer <NUM> faces the front tool <NUM>, and the non-compressible layer <NUM> faces the back tool <NUM>.

The mould is then closed. The travel of the front and back tools <NUM>, <NUM> toward one another comprises the same first, second and third parts as described above for the first trim part <NUM>.

The invention has been described for an example in which two trim parts, with different thicknesses, are manufactured. However, the invention encompasses cases where three trim parts, having thicknesses different from one to another, are manufactured, or more than three trim parts. For instance the third trim part do not have a decorative layer. The settings of the mould typically are adjustable such that the front and back final positions are freely selected each in a continuous range.

The terms front and back tools are not used in a limitative way. Typically, the two halves of a mold are placed above one another and are moved vertically, as shown on the figures. However, the invention could be implemented with the front and back tool moving along a horizontal direction with respect to one another. The main direction, along which the front and back inserts move with respect to the front and back fixed parts, is horizontal. The front tool is above the back tool in the example depicted on the figures. In another example, the back tool is above the front tool.

The first and second trim parts, in the example described above, respectively have a compressible layer, and do not have a compressible layer. According to another example, the first and second trim parts both have a compressible layer. The first and second front final positions are then chosen taking into account the expansion of the compressible layer of the two trim parts, such that the A-surface of the first and second trim parts are at the same position with respect to the respective surrounding areas of the first and second trim parts.

According to another example, the first and second trim parts both do not have a compressible layer. In this case, the settings adjustment device could adjust the followings settings of the mould: the final front position of the front insert with respect to the front fixed part, and the final back position of the back insert with respect to the back fixed part. In this case, the back insert remain fixed with respect of the back fixed part during all the travel of the front and back tools toward one another.

Claim 1:
A method for manufacturing first and second trim parts (<NUM>, <NUM>) of a vehicle, the first trim part (<NUM>) having a first thickness and the second trim part (<NUM>) having a second thickness different from the first thickness, the method comprising the following steps :
- adjusting settings of a forming mould (<NUM>) to first values;
- introducing the first trim part (<NUM>) between a front and a back tool (<NUM>, <NUM>) of the forming mould (<NUM>), the front tool (<NUM>) having a front fixed part (<NUM>) and a front movable insert (<NUM>) movable with respect to the front fixed part (<NUM>) along a main direction, the back tool (<NUM>) having a back fixed part (<NUM>) and a back movable insert (<NUM>) movable with respect to the back fixed part along the main direction;
- closing the forming mould (<NUM>) by moving the front and back tools (<NUM>, <NUM>) toward one another, the first values of the settings being chosen such that, when the forming mould (<NUM>) is closed, the front insert (<NUM>) has a first front final position along the main direction with respect to the front fixed part (<NUM>) and the back insert (<NUM>) has a first back final position along the main direction with respect to the back fixed part (<NUM>);
- adjusting settings of the forming mould (<NUM>) to second values different from the first values;
- introducing the second trim part (<NUM>) between front and back tools (<NUM>, <NUM>) of the forming mould (<NUM>);
- closing the forming mould (<NUM>) by moving the front and back tools (<NUM>, <NUM>) toward one another, the second values of the settings being chosen such that, when the forming mould (<NUM>) is closed, the front insert (<NUM>) has a second front final position along the main direction with respect to the front fixed part (<NUM>) different from the first front final position, and the back insert (<NUM>) has a second back final position along the main direction with respect to the back fixed part (<NUM>), different from the first back final position.