Adaptable device for shaping a bodywork element.

Abstract

The invention relates to a bodywork shaping device (1) for a body panel (2) designed to shape and position the body panel (2) on a chassis (3), the device (1) comprising a rigid structure (7) to which is fixed at least one flexible membrane (12) delimiting at least partially a hermetic volume (14), the rigid structure (5) and each membrane (12) delimiting a bearing surface (15) intended to be in contact with the bodywork panel (2), the hermetic volume (14) containing a fluid and a granular material, the latter being capable of undergoing a phase transition between a flowing phase and a static phase under the effect of a change in fluid pressure, means for modifying the fluid pressure in the hermetic volume (14), so as to modify the phase of the granular material to modify the shape of the bearing surface (15). (Figure 2)

Description

Title of the invention: Adaptable device for shaping a bodywork element.

[0001] The technical field concerns adaptable devices for shaping a bodywork element, assemblies comprising a template with such a device and finally methods for shaping a bodywork element.

[0002] It is becoming increasingly common for a motor vehicle to be offered to customers in several different versions, in particular with various body silhouettes. Each silhouette generally has its own particularities which imply structural differences between each silhouette, in particular on the body elements attached to the chassis.

[0003] Certain bodywork parts, in particular parts formed from sheet metal, are shaped on the chassis by ensuring local adjustments of the parts using specific tools before their attachment. These specific tools are of several types, all of which have defects, in particular by causing local deformations of the bodywork parts as well as inhomogeneities in the adjustment clearances between the chassis and the bodywork parts. Furthermore, a specific tool is generally required for each vehicle silhouette. These different tools are generally stored near the assembly lines to allow rapid adaptation of the assembly robots according to the silhouettes produced. However, the areas located near the assembly lines are particularly congested.

[0004] Among the bodywork parts that have a shape specific to each silhouette, there are the roof panels that must be positioned and conformed to the chassis. The specific tools for these conformations are particularly bulky and occupy a significant space in the areas located near the assembly lines. The diversity of silhouettes necessarily leads to an increase in development and production costs, in particular because of the diversity of specific tools, as well as a complication in the management of the assembly lines and the assembly of the different versions of the vehicle.

[0005] Thus, there is a need to reduce the diversity of tools allowing the shaping of body parts.

[0006] The present invention aims to overcome the problems set out above. In this technical context, one aim of the present invention is to provide a device for shaping an adaptable bodywork element which makes it possible to reduce the diversity of devices required and which facilitates the assembly of the different silhouettes of a family of vehicles.

[0007] For this purpose, the present invention relates to a device for shaping a bodywork element designed to shape and position the bodywork element on a motor vehicle chassis with a view to fixing it thereto, the device comprising a rigid structure on which is fixed a flexible membrane delimiting at least in part a hermetic volume, the rigid structure and the membrane delimiting a bearing surface intended to be in contact with the bodywork element and designed to exert pressure on the latter, the hermetic volume containing a fluid and a granular material, the granular material being capable of undergoing a phase transition between a flowable phase and a static phase under the effect of a change in pressure of the fluid contained in the hermetic volume, the device comprising means for modifying the pressure of the fluid in the hermetic volume, so as to modify the phase of the granular material,the granular material contained in the airtight volume allowing the shape of the support surface to be modified.

[0008] The invention also relates to a shaping assembly comprising, on the one hand, a device according to the invention and, on the other hand, a template having a reference surface making it possible to distribute the granular material in the flowing phase in the hermetic volume so as to form, after a phase transition of the material to a static phase, a support surface having a shape complementary to the reference surface.

[0009] Finally, the invention relates to a method for shaping and positioning a bodywork element using an assembly according to the invention consisting of forming the support surface using the template and then arranging and shaping a bodywork element on a vehicle chassis using the support surface of the device.

[0010] Thus, the device according to the invention allows the shaping of a bodywork element: the device makes it possible to give the bodywork element a shape, a curvature and / or a curve in order to facilitate a subsequent assembly operation, for example by welding, on the chassis thanks to the support surface. The support surface delimited by the frame and the flexible membrane is placed in contact with the bodywork element and pressure on the rigid frame makes it possible to transmit the force to the bodywork element to shape it. The granular material contained in the flexible membrane, mixed with the fluid, can change phase and transit from a flowing phase, in which it has a behavior similar to a fluid, to a static phase, in which it has a behavior similar to a solid, and vice versa. This change of phase makes it possible to distribute the granular material in the flexible membrane in order to modify the support surface.By means of the means for modifying the fluid pressure in the membrane, the granular material can then be fixed in the static phase in order to give the support surface a rigidity allowing a support force exerted on the frame to be transmitted to the bodywork element. The device is thus . adaptable at will since it is sufficient to modify the support surface by changing the pressure of the fluid contained in the membrane. In order to properly distribute the granular material, a template of the assembly can be used: thanks to its reference surface, the granular material can be distributed in the membrane, in the flowing phase, in order to match the reference surface. The granular material is then fixed in the static phase to form at least part of the support surface complementary to the reference surface. Thus, with the device according to the invention it is no longer necessary to have a plurality of tools each corresponding to a particular silhouette. A device according to the invention can adapt to each of the silhouettes.

[0011] According to one embodiment of the invention, each membrane is an elastic membrane.

[0012] According to one possibility, the fluid is a gas, the phase transition from the flowing phase to the static phase being obtained by a decrease in the pressure of the gas in the sealed volume. Conversely, an increase in the pressure of the gas allows a phase transition from the static phase to the flowing phase.

[0013] According to one embodiment, the granular material contained in the hermetic volume makes it possible to vary the thickness of the device.

[0014] According to one possibility, the rigid structure forms a frame.

[0015] According to one possibility, the method further comprises a step consisting of welding the bodywork element shaped and positioned on the chassis.

[0016] The invention will be better understood on reading the detailed description which follows, given solely by way of non-limiting example and made with reference to the appended drawings in which:

[0017] [Fig-1] [Fig.l] represents a perspective view of a device according to the invention and a vehicle on which a bodywork element must be positioned and shaped;

[0018] [Fig.2] [Fig.2] represents a detailed view of the device of [Fig.l] showing the membrane.

[0019] In these figures, the same references are used to designate the same elements.

[0020] A shaping device 1 according to the invention is illustrated in Figures 1 and 2. The device 1 makes it possible to shape and position a bodywork element 2, illustrated in [Fig.2], on a chassis 3 of a motor vehicle 4, visible in the figures, with a view to fixing the bodywork element 2 to the chassis 3. In the embodiment illustrated in the figures, the device 1 is intended to shape a roof panel 5 on the chassis 3. The roof panel 5 is made of a pre-cut sheet 6 of metal, for example aluminum. The vehicle 4 has several bodywork silhouettes available, one of which is illustrated in [Fig.l]. The roof panel 5 is adapted to the silhouette shown in [Fig.l], the other silhouettes having for example a curve or a different length.

[0021] The device 1 comprises a rigid structure 7 forming a frame 8. In the embodiment illustrated in the figures, the frame 8 has two longitudinal bars 9 each consisting of three rectilinear sections 10 assembled end to end and inclined relative to each other. The two longitudinal bars 9 are connected to each other by at least two transverse bars 11 whose respective lengths are advantageously adjustable. The connections between the transverse bars 11 and the longitudinal bars 9 are also advantageously articulated.

[0022] The device 1 according to the invention also comprises, fixed to the rigid structure 7, at least one, in this case two flexible membranes 12, each extending between an inner face and an outer face 13, which delimit at least in part a hermetic volume 14. In a first embodiment, the hermetic volume 14 is delimited by the frame 8 and the inner face of each membrane 12. Alternatively, the membranes 12 fully delimit the hermetic volume 14.

[0023] The rigid structure 7 and the membranes 12 delimit a bearing surface 15. Advantageously, each membrane 12 is made of elastic material such as rubber. The bearing surface 15 is intended to be in contact with the bodywork element 2 and is designed to exert pressure on the latter.

[0024] Each membrane 12 is advantageously impermeable to gas, such as air, so that it is possible to maintain a differential pressure between the inner face of the membrane 12 and the outer face of the membrane 12 in contact with the outside air at atmospheric pressure, for example. In the embodiment illustrated in the figures, each membrane 12 forms a cylindrical tube 16 each extending along at least a portion of a longitudinal bar 9. The bearing surface 15 is formed by a portion of the outer faces 13 of each membrane 12. In this configuration, the hermetic volume 14 is split into two parts, each corresponding to the inner volume of one of the tubes 16.

[0025] The hermetic volume 14 contains a fluid and a granular material, not illustrated in the figures.

[0026] The fluid is for example a gas such as air. As for the granular material, it is chosen so that it is capable of undergoing a phase transition between a flowing phase and a static phase under the effect of a change in pressure of the fluid contained in the hermetic volume 14. In the flowing phase, the material exhibits behavior comparable to a liquid and can in particular flow. In the static phase, the material exhibits behavior comparable to a solid and is capable of retaining a particular shape. During a phase transition between the two aforementioned phases, such a granular material has a modulus of elasticity which varies by a factor of at least 10.

[0027] By way of non-limiting examples, the granular material may include small individual solid granules or grains made from any type of metallic, insulating, or semiconducting solid, including one or any combination of one or more of the following: plastic or polymer particles, coffee grounds, corn starch, crushed glass, sand, rice, sawdust, crushed nutshells, oats, corn flour, metal particles, dried and crushed corn husk, salt, seeds, crushed rubber, rocks, and other items known in the art.

[0028] The device 1 further comprises means for modifying the pressure of the fluid in the hermetic volume 14, so as to modify the phase of the granular material. Such means may, for example, comprise a valve, not shown in the figures, arranged on each membrane 12, designed to modify the quantity of fluid contained in the hermetic volume 14. The means advantageously comprise a gas compressor coupled to each valve.

[0029] Finally, the granular material contained in the hermetic volume 14 makes it possible to modify the shape of the bearing surface 15. For this purpose, it is present in sufficient quantity and occupies a sufficient proportion of the hermetic volume 14.

[0030] The distribution of the granular material in the hermetic volume 14 is carried out when the granular material is in the flowing phase. Once the desired distribution is obtained, the pressure of the gas contained in the hermetic volume 14 is modified, in this case lowered to create a pressure difference between the inner face and the outer face 13 of the membrane 12 so as to obtain a phase transition of the granular material to freeze it in the static phase. A typical pressure difference required to obtain such a phase transition is of the order of 30 KPa or more. In the embodiment illustrated in the figures, the distribution of the granular material makes it possible to vary the thickness of each bead 16 along each transverse bar 9 in order to modify the thickness of the device 1 along a longitudinal axis parallel to each transverse bar 9.It should be noted that it is not necessary for the distribution of the granular material in each sausage 16 to be symmetrical.

[0031] An assembly according to the invention is formed of a device 1 according to the invention and a template, not shown. In order to correctly distribute the granular material in the hermetic volume 14, the template is advantageously used. The template has for this purpose a reference surface making it possible to distribute the granular material in the hermetic volume 14 so that each membrane 12 takes on the shape complementary to the reference surface.

[0032] Thus, the assembly according to the invention makes it possible to implement a method according to the invention for shaping and positioning the bodywork element 2. The method consists of forming the support surface 15 using the template and then arranging and shaping the bodywork element 2 on the chassis 3 of the vehicle 4 using the support surface 15 of the device 1. Advantageously, the method further comprises a step consisting of welding the bodywork element 2 shaped and positioned on the chassis.

[0033] Thus, the device 1 according to the invention makes it possible to conform several bodywork elements 2 of a vehicle family by adapting to each silhouette thanks to an adapted distribution of the granular material. The device 1 therefore makes it possible to reduce the diversity of tools necessary for the assembly of vehicles having different silhouettes.

[0034] The invention is not limited to the embodiment of the device or assembly described above, only by way of example, but other embodiments can be designed by those skilled in the art without departing from the scope and scope of the present invention.

Claims

Claims

1. Device (1) for shaping a bodywork element (2) designed to shape and position the bodywork element (2) on a chassis (3) of a motor vehicle (4) with a view to fixing it thereto, the device (1) comprising a rigid structure (7) on which is fixed at least one flexible membrane (12) delimiting at least in part a hermetic volume (14), the rigid structure (7) and each membrane (12) delimiting a bearing surface (15) intended to be in contact with the bodywork element (2) and designed to exert pressure thereon, the hermetic volume (14) containing a fluid and a granular material, the granular material being capable of undergoing a phase transition between a flowable phase and a static phase under the effect of a change in pressure of the fluid contained in the hermetic volume (14), the device (1) comprising means for modifying the pressure of the fluid in the hermetic volume (14),so as to modify the phase of the granular material, the granular material contained in the hermetic volume (14) making it possible to modify the shape of the support surface (15).,

2. Device (1) according to claim 1, characterized in that each membrane (12) is an elastic membrane (12).

3. Device (1) according to claim 1 or 2, characterized in that the fluid is a gas, the phase transition from the flowing phase to the static phase being obtained by a reduction in the pressure of the gas in the sealed volume (14).

4. Device (1) according to one of claims 1 to 3, characterized in that the granular material contained in the hermetic volume (14) makes it possible to vary the thickness of the device (1).

5. Device (1) according to one of claims 1 to 4, characterized in that the rigid structure (7) forms a frame (8).

6. Shaping assembly comprising, on the one hand, a device (1) according to one of claims 1 to 5 and, on the other hand, a template having a reference surface making it possible to distribute the granular material in the flowing phase in the hermetic volume (14) so ​​as to form, after a phase transition of the material to a static phase, a support surface (15) having a shape complementary to the reference surface.

7. Method of shaping and positioning a car- bodywork (2) using an assembly according to claim 6, the method consisting of forming the bearing surface (15) using the template then arranging and conforming a bodywork element (2) on a chassis (3) of a vehicle (4) using the bearing surface (15) of the device (1).

8. Method according to claim 7, characterized in that it further comprises a step consisting of welding the bodywork element (2) shaped and positioned on the chassis (3).

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