CA2345298A1

CA2345298A1 - Method and device for producing a van body, and van body thus produced

Info

Publication number: CA2345298A1
Application number: CA002345298A
Authority: CA
Inventors: Robert Nolte
Original assignee: RONO SYSTEMTECHNIK AG
Current assignee: Individual
Priority date: 1998-09-24
Filing date: 1999-09-09
Publication date: 2000-04-06
Also published as: JP2002525244A; BR9913915A; CN1319060A; TR200100856T2; DE19843969A1; ZA200102410B; PL346834A1; KR20010079900A; WO2000018637A1; EP1115607A1; AU5405699A

Abstract

The invention relates to a method for producing a box-type van body (1) for transport vehicles. A multi-layer flat part (9) substantially consisting of thermoplastic material has a supporting center (7) and covering layers (8) extending from both sides thereof. According to the method, the flat part, whose surface corresponds to at least two adjoining side walls of the van bo dy (1), is heated in substantially linear zones which are defined by the edges of the adjoining side walls (2, 3) of the van body (1). It is then folded in these zones. The flat part (9) is formed by a plurality of sandwich boards ( 6) which adjoin at the small faces thereof and are joined in a thermoplastic manner. A box-type van body (1) for transport vehicles produced according to said method has integral walls produced from the flat part (9) which is shap ed in a thermoplastic manner. Said walls adjoin at least in one circumferential direction of the van body (1) and form an at least angular or V-shaped parti al van body (1). The adjoining edges of said walls and optionally of additional walls are especially joined in a thermoplastic manner.

Description

Method and device for producing a van body, and van body thus produced The invention relates to a method for producing a box-type van body for transporting vehicles.
Such bodies are already known in a large number of designs. Thus, van bodies are known which are assembled from individual plate shaped elements and are joined at edge areas, if needed also in the planar areas by means of profiled bars. The assembling of such a van body is, however, quite time consuming and, therefore, also expensive.
Furthermore, with the conventionally used wooden boards a comparable large weight is arrived at.
Further known are aluminum van bodies of the so called cIarnped van body assembly design, in which aluminum sheets are joined by profiled bars. Also here the drawback exists that a comparatively high weight is arrived at and that the assembling is quite time consuming. A further drawback is that the comparativel'.y thin metal sheets, specifically if used for motor vehicles, are easily exited to vibrate in case of uneven roadways and then produce a corresponding noise.
In order to seal between the plates and the profiles plastic m<~terial strips are made use of which, however, grow porous after a prolonged time due to the influence of the relative movements between plates and profiled bars and also under the influence of W-rays and then lead to leaky areas at the van body.
In the case of the clamped van body assembly design wooden panels are quite often placed at the inner side of the thin outer skin of aluminum. Means for securing the cargo for instance in form of belts or similar can than be mounted to these wooden panels.
Furthermore, the inner wood paneling shall provide for a protection against damages by the cargo. Further van bodies are known which consist of compound plates with a foamed PU- core and GFK-layers laminated thereupon. Such bodies are, however, extremely expensive and quite demanding regarding their production.

AlI three of these various embodiments of van-bodies in accordance with the prior art have in common that due to the multitude of materials, only a limited or inferiorly workable possibility of repair is given. In case of the clamped van body design, for instance, there is a problem that the outer skin which consists of a thin aluminum material can easily be damaged for instance by branches, but than, however, considerable additional operations are necessary, namely they removing of the inner wood paneling in order to access the area to be repaired. In case of a repairing of the aluminum-insert profile bars a welding without a considerable assembly work is impossible because otherwise the bordering materials would not stand up against the heat strain.
Object of the present invention is to provide a method for producing a van body which can be practiced specifically easy and fast and necessitates a small expenditure of machines only. A accordingly produced van body shall display a excellent sealing property and be resistant against influences of the environment, shall have a small weight and if needed shall lend itself to a easy recycling. Finally, a device for producing the van body shall be provided which is of a simple design and is inexpensive and which also can be operated if necessary by non-professionals.
With regard to the method of production for a van body in accordance with the invention it is proposed to heat a mufti-layer flat part consislting substantially of thermoplastic material having a supporting center and covering layers at both sides thereof, of which the surface corresponds to at least two adjoining side walls of the van body at substantially linear zones which correspond to edge boundaries of the adjoining side walls of the van body and to bend it at those zones.
The main assembly operation for producing the van body consists in a folding or bending, respectively of a correspondingly dimensioned sandwich flat part under influence of heat, so that thereafter at least the largest part of the van body is available consisting practically of one part.

Experiments have shown that that the expenditure on time fix a producing of such a van body amounts to only a fraction of up to one tenth of the time needed to produce a conventional design.
The use of a thermoplastic material for the flat part to be foamed allows a simple working under the influence of heat and has due to the practically homogeneous structure of the material the advantage of a considerable saving of material and the substantial advantage that it can be easily recycled. Additionally, a large advantage is the considerable saving on weight which leads to a great many advantages resulting thereof, specifically in combination with vehicles.
Advantageously several mufti-layer sandwich plates adjoining each other at their narrow faces and consisting substantially of a thermoplastic material, having a supporting core and at both sides thereof covering layers are joined in a thermoplastic manner to form the flat part, whereby to this end a portion of the supporting core of the face side of one of the plates to be joined is removed for producing a receiving recess and from the other sandwich plate a portion of the cover layers is removed at its face side, then the core zone is inserted into the receiving recess and thereafter the fiwo sandwich plates are joined under influence of pressure and heat.
This also adds substantially to a simple production, because the sandwich plates can be produced practically in series and unitarily relative to the size; independent from the size of the flat part. The sandwich plates used can be produced practically endlessly at a predetermined width and can then be cut to size in accordance with the circumferential length of a van body. Should the width of the sandwich strand not be sufficient, a corresponding number of further sandwich strands may be added thereto laterally in accordance with the above described procedure.
The connecting together of the individual sandwich plates is possible at a small expenditure due to the property of being able to be welded in a thermoplastic manner, and due to the zone wise overlapping meshing a rigid connection is arrived at and due to this a practically homogeneous structure having at all areas substantially the same strength properties. Advantageously it is foreseen that alI sides located at least in a direction of the circumference of the van body structure are; part of the flat part and that after the folding of the sides the possibly each other adjoining free ends are joined together at least under the influence of heat, preferably meshing with each other.
Thus, it is possible to produce in practically one production step a complete van body which needs only a few additional processing steps, for instance in order to connect it to the chassis of a vehicle or for the mounting of a door or sirrular. There exists, thereby, the possibility to produce in a interconnected manner the side walls, the roof and the floor from one single piece or even additionally to include at least one of the front walls, It is, furthermore, foreseen, that for a joining of a seen in ci:rcumferential direction angle shaped or U-shaped or closed partial van body structure to a wall extending at an angle thereto and consisting of one or several sandwich plates, at the one hand a supporting core portion is removed partly at one of the facing ends of one wall and at the face end of the other wall the covering layers are removed up to a certain zone, and that the cover layers of the zone without the supporting core are joined in a thermoplastic manner and in an overlapping manner at least to the zone of the other wall having no covering layers.
By means of this stable joints can also be produced at the corner areas of walls joined to each other. Also here a welding of the thermoplastic material is carried out by an influence of heat and no additional joining elements are needed.
A advantageous embodiment of the invention foresees that a preferably thermoplastic tube is inserted in the flat part at least at the zone of a foreseen fold and that the tube is heated for a folding of the flat part and the folding is carnedf out thereafter.
The inserted tubes can be used as installation channels, specifically for electric cables.
It is, however, especially advantageous if the supply of heat proceeds by tubes located in fold zones at the zones of the tubes and especially through the tubes. By this supply of heat through the tube the plastification of the folding zone proceeds from the inside and accordingly especially effective and fast. In this case the. zones of the folds are determined by the location of the tubes and this forms a additional stabilization of the edge.

- S -In order to mount a door or similar there exists the possibility that at least at one circumferentially extending face rim of a in circumferential direction U-shaped or closed part-van body structure a portion of the core area is removed for the forming of a receiving groove and a end profile piece is set into this receiving groove and joned therein. Hinge and/or Iock parts may be mounted to this end profile piece.
This end profile piece may if needed be formed of a profiled aluminum strip, for instance a square tube. Instead of a aluminum tube it may also be possible to insert a profiled strip of a thermoplastic material which may be welded in a thermoplastic manner to the sandwich plate.
In order to form a hinge and for a mounting of a door it is I>ossible to locate between walls of the van body which are to be pivotally mounted tol;ether recesses at their longitudinal edges which face each other in a in the longitudinal direction staggered manner, into which the respective remaining edge portions of the other side engage, and that pivot pins are inserted into the not removed edge areas. Also in this case a closing off profiled strip may be inserted into the outer edges, According to a further embodiment of the invention it is foreseen to slit a thermoplastic tube in its longitudinal direction and to place heating wires <~t the edges of the slit, and to insert thereafter the tube with the slit facing the inner side of the fold at the angled area between adjoining walls into the flat piece or between l:he sandwich plate(s), respectively, and that thereafter during the thermoplastic folding the edges of the slits are placed against each other and welded together.
In the folded or bent, respectively state of the flat part a addfitional reinforcement can be obtained by the melting together of the edges of the slits which in the initial position are at a distance from each other corresponding to the foreseen fold. During the folding process proper the force needed for the folding is reduced.
The invention refers also to a van body for transport vehicles produced in accordance with the method of the present invention. This van body is characterized by walls adjoining each other in a circumferential direction of the van body forming at least one angularly or U-shaped van body portion, and which consist integrally of a thermoplastic - g -deformed flat piece having a supporting core with cover layers located at bath its outer sides, and in that the other adjoining edges of these and possibly further walls are interconnected especially in a thermoplastic manner.
Such as already described in part in connection with the method in accordance with the invention, the foreseen structure of the van body leads to substantial advantages in addition to the production also regarding the mounting to vehicles. Due to the use of sandwich plates the structure of the body displays a high st<~bility at a at the same time low weight, whereby the low weight benefits further by not needing the otherwise necessary mounting means such as connecting bars, edge b~~rs, screw bolts, angle pieces and similar. In comparison with van bodies of plywood the weight can be reduced by more than 50 %. For vehicles this means a considerable incn~ease of the payload and thus of the economy. Due to the thermoplastic integral connection of the materials of the walls of the body, the body structure is leak-tight and weatherproof.
A embodiment foresees that securing elements with a roughly spherical segment shaped supporting body of a thermoplastic material are foreseen, that the supporting body includes at its concave side a transverse pin consisting preferably of steel and being located at a distance from the bottom of the supporting body and is joined by its concave side in a thermoplastic manner to a wall of the van body and engages thereby at least at a zone into the wall.
Such securing bodies can be mounted at arbitrary places of the van body, whereby also here a thermoplastic welding connection is foreseen. For this, the supporting body and the place of the mounting to the wall can be correspondingly heated and the joining is made by pressing the two parts together. Such mounting bodies are especially useful for the securing of the cargo whereby in regard to this the mounting bodies are expediently placed in rows at the inner sides of opposite walls of the var.~ body and than form practically a replacement for the otherwise conventional securing rails.
A advantageous further embodiment of the invention foresees that the sandwich plates) comprises) one or more condensed zones as connecting points for a joining of sandwich plates and/or for a joining to other parts, and that at these condensed zones the cover layers have relative to their by the supporting body caused initial position being at a distance from each other, a condensed position with a at IE:ast reduced distance. The van body features at these connecting zones a high stability .due to the condensing by a heat flow, so that a corresponding transmission of forces is possible. The zones of the joint form here within the compound system no weakened area and the excellent strength properties of the sandwich plate and the van body formed therewith, respectively, are effective thereby also at the total structure. It is hereby also important that the two cover layers are included in the zone of the joint and thus for the transmission of forces. Because the absorption of forces proceeds substantially through these cover layers, such is of a substantial importance for a lugh stability in the mounting and connecting zone.
The invention relates also to a device for practicing the method and also for the producing of a van body. This device is characterized in that it comprises a support for a multilayer sandwich plate consisting substantially of a thermoplastic material including a supporting core and at both sides thereof cover layers or a flat part formed of one or a plurality of joined sandwich plates and that the support has by at least one of its edges a heating zone.
By means of such a device it is possible to form by a specifically simple procedure plate shaped thermoplastic flat parts or similar which can be folded, whereby the thermoplastic plate is positioned on the support in such a manner that it rests by the foreseen folding zone along the heating zone. When the heating zone is activated, the portion of the plate protruding over the heating zone can be folded in case of a su~cient heating. In a simplest case this occurs by the influence of gravity such that as a rule folding drives are not needed. If necessary the folding process can be supported manually.
A embodiment of the device according to the invention foresees that the support is formed substantially by a supporting frame which includes at least one heatable tube - g -which can be heated at an edge for forming a heating zone. By means of this it is possible to realize a folding device with a minimum of expenditure. Regarding its cross-sectional shape and its position this heatable tube can be made to conform with the prevailing demands.
In order to produce parts with a plurality of folds it is advantageous if the supporting frame includes tubes located at edges and arranged advantageously in parallel opposite of each other which can be heated and of which the distance can advantageously be adjusted. By means of this thermoplastic plates can be folded simultaneously at areas located at a distance from each other.
it is preferably foreseen that the supporting frame is located within the course of a production line for van bodies and especially at a feeding table for a flat part consisting of one or several sandwich plates and bordered by a following conveyor with rollers for a transporting the partial van body away. Specifically in case of a series production it is possible to arrive therewith at very short cycle times with a corresponding high production output number.
According to a further embodiment of the invention the device may also comprise a pressing apparatus with pressing pads which can be heated and/or pressing rollers which can be heated and which preferably are placed at both sides at opposite areas of the joining zone of sandwich plates or flat pats in order to join edges of flat parts or sandwich plates which mate at the narrow sides.
By means of this pressing apparatus the zones of the joints :may be acted upon under a influence of heat in such a manner that at the one hand a integral thermoplastic joint and at the other side continuous planar outer surfaces are produced. Further, a certain condensing of the material occurs by the acting upon by pressure which leads to a high stability at the zone of the joint. There exists thereby, however, also the possibility to carry out the thermoplastic welding itself through integrated heating wires and the forming for planar, continuous outer surfaces by pressure pads or rollers.
Additional embodiments of the invention are set forth in the further dependent claims.
Below, the invention will be described still more in detail regarding its substantial particulars with reference to the drawings.

There is illustrated schematically in:
Fig. 1 a perspective rear side view of a truck with a van body according to the invention, Fig. 2 a flat part consisting of sandwich plates for producing a partial van body, Fig. 3 a device for a folding of a thermoplastic flat ;part to a U-shaped partial van body, Fig. 4 a side view of two sandwich plates prepared to be connected to each other, Fig. 5 the sandwich plates illustrated in Fig. 4 in a state plugged into each other as well as pressure punches arranged at the areas of this connection zone, Fig. 6 the two sandwich plates illustrated in Fig. 4 i,n a state in which they are welded together in a thermoplastic manner, Fig. 7 a pressing apparatus with pressing pads for the connecting of sandwich plates, Fig. 8 a joined corner area, Fig. 9 another embodiment of a corner joint, Fig. 10 a sandwich plate with tubes inserted in the zone of foreseen folds, Fig. 11 a schematic illustration of a device for folding sandwich plates with tubes integrated therein for the heat supply, Fig. 12 a partial view of a sandwich plate with a longitudinally slit tube with heating wires located at the edges of the slit , which is foreseen to be placed at the zone of a foreseen folding, Fig. 13 a sandwich plate having a longitudinally slit tube in a folded state and Fig. I4 a perspective illustration of a sandwich plate ,with a mounting zone for a mounting to a supporting element.
Fig. 1 illustrates in a perspective partial view the rear side of a truck with a van body I .
The box shaped van body I illustrated in the embodiment includes two side walls 2 and 3, a top wall 4 and a bottom, as well. The front wall located at the front end of the van body is not visible.
The van body or body is composed of several sandwich plates 6 (see also Fig. 4 to 6), which consist of a supporting core 7 with outer covering layers 8. A plurality of such sandwich plates are combined to a flat part 2 (Fig. 2) from which the body is produced.
The sandwich bodies consist at least to the largest part of a thermoplastic material such that they can be correspondingly deformed under a influence. of heat and a flat part 9 such as for instance illustrated in Fig. 2 may be folded to a van body or partial van body.
As already mentioned above, the flat part is composed of several sandwich plates 6.
Such sandwich plates 6 lend themselves to be produced in a predetermined width practically endlessly, so that they may be placed adjoining each other either extending in the longitudinal direction of the body or, however, in its circumferential direction and joined together in order to form a suitable flat part 9.
The Figs. 4 to 6 illustrate a suitable joining method, whereby initially according to Fig.
4 at the left sandwich plate a portion of the supporting core its removed for forming a receiving groove I O and from the other sandwich plate at its front end portions of the cover layers 8 are removed. The core area which has been fi.eed of the cover layers 8 is then inserted into the receiving groove 10, whereby the cover layers 8 overlap each other somewhat such as is schematically illustrated in Fig. 5. By aid of a pressing device 11 which comprises heated pressing pads 12, 13 the zone of the joint 14 is thereafter acted upon by pressure and is heated, so that the ends of the: two sandwich plates 6 set into each other are welded together in a thermoplastic manner. The hot pressure pads 12,13 are led together to a distance which corresponds to the thuckness of the sandwich plates, so that the zone of overlap of the cover layers is urged somewhat towards the inside and forms a slightly thickened zone 15 such as can be seen in Fig. 6.
By this thermoplastic integral fusing flat parts 9 of any dimensions nnay be produced.
Especially advantageous is thereby that no tosses of strength occur, so that practically the same properties regarding the stability are present over the entire :flat part .
Fig. 7 illustrates a pressing device 11 in a somewhat more detailed state whereby it is here specifically recognizable that the pressure pads 12 are rnounted on pressing arms 16 which reach transversely over the sandwich plates) 6. Ait this embodiment the pressing pads 12 are equipped with pressing rollers 7 which are heated electrically. In this embodiment a additional material strip 18 is placed at the zone of the joint onto the joined zone 14 and welded in a thermoplastic manner to the two sandwich plates which are to be joined. The material strip 18 which is fed for instance from a supply roll I9 can consist specifically of the same material which is also used for the cover layers 8. By the hot pressing together by aid of the pressure pads 12 or the pressure rollers 17, respectively, also here a condensing of the materi,~l can occur insofar in that a continuous flat surface is arnved at.
The two sandwich plates to be connected together and the pressing device can be positionable either step wise or continuously relative to each other along the joint 14. It is preferably foreseen that the sandwich plates 6 rest stationa~.ry on a support and that the pressing device 11 is positioned.
In order to form the van body initially and as described above, a flat part 9 such as for instance illustrated in Fig. 2 is assembled from sandwich plates 6. This flat part 9 can - i2 -then have a circumferential shape which corresponds to the development shape or partly developed state shape of the van body. In the embodiment according to Fig. 2 the flat part 2 includes the two longitudinal walls 2 and 3, the roof wall 4 and a end wall 20. For sake of clearness the borders of the individual walls are illustrated by broken lines which also form the folding lines when shaping the van body.
By means of the flat part 9 illustrated in Fig. 2 a partial body of a U-shaped cross section with a front end wall 20 can be formed, which then still must be joined to the bottom 5 in order to obtain a van body 1 in accordance with Fig. 1. There exists, however, the possibility that additionally bottom sections adjoin at the outside the longitudinal edges of the side walls 2 and 3, so that after thE; shaping of the van body merely a longitudinal joint zone 14 is present in the bottom area (Fig. 1).
A device for a forming of a flat part 9 to a van body or partial body is illustrated in Fig.
3. This device 21 comprises a support 22 with heating zones 23 located along its edge areas. In this embodiment the support is designed table like with a supporting frame 34, whereby the height of the support according to the arrow Pfl and also the distance between the two heating zones 23 are preferably adjustable in accordance with the double arrow Pfl. By means of this a adjusting of the device to variously dimensioned van bodies is made possible.
in the embodiment according to Fig. 3 a rectangular flat part 8 is fed to the device 21 whereby it is positioned in such a manner that it comes to lie with the areas of the intended fold 25 on the heating zones 23. By an activating of the heating zones 23 the areas of the flat part 9 resting thereupon are heated and can be bent downwards merely due to the force of gravity or, however, additionally aided manually.
The device 21 with the supporting frame 24 and the upper support is arranged in the embodiment within the course of a production line. A feeding table 26, which is designed here as a roller conveyor is utilized for the feeding.. This feeding table 26 can be moved for a passing on of the flat part 9 to the support 22 towards same in accordance with the arrow Pf3 and for the folding process it: can be moved back according to the arrow Pf4 at Ieast by the distance of the of the flat part 9 projecting beyond the heating zone facing the feeding table 26. Thus, a free space is then produced such that also at the le$ side a portion of the flat part 9 can be folded downwards. After the folding process a U-shaped partial body I a is available which can be transported off by means of a roller conveyor 27 adjoining the device 21 fo:r a further processing.
In the embodiment heatable tubes 28 are foreseen in the heating zones 23 arranged at edges at the supporting frame of which the distance from each other and also their height position may be adjusted in accordance with the doulble arrows Pfl and Pf2. The cross section of the heatable tubes and, thereby, specifically their surfaces which come to contact the flat part 9 may be designed variously depending from the respective required radiuses of the fold or the foreseen deformations, respectively. The tubes 28 may be heated electrically or a liquid could be made to flow through same when formed as hollow tubes.
In Fig. 3 the hollow tubes 28 which can be heated are connected through pipes for liquids to a heating device. It also shall be mentioned that a folding abutment which can be set for various folding angles may be located under the fi.~bes which can be heated.
There exists, furthermore, the possibility to equip the folding device 21 with further tubes 28 which may be heated, in order to produce besides the doubly folded van body illustrated in Fig. 2 also four times folded van bodies with bottom parts formed directly thereon. Furthermore, further heatable tubes may be foreseen which are oriented transverse to the illustrated heatable tubes 28 in order to undertake a folding of end walls 20 (see Fig. 2).
In order to join the corner edges, cover layers which project at an edge of the one wall are joined in a thermoplastic fashion to the supporting core and/or to the cover layers of the other wall. The Figs. 8 and 9 illustrate somewhat schematically such corner joints which Iead to a high stability. According to Fig. 8 respective cover layers 8 of one sidewall 3 which project beyond the supporting core 7 are folded at the front end and placed on top of each other, and the joining end for instance; of a front wall 20 which has been prepared in the same way set into the angle of the fold formed thereby. In this position then, a thermoplastic welding of the parts which contact each other takes place by means of pressure pads and under the influence of heat and pressure.

Fig. 9 illustrates a corner joint at which only the one wall 3 lhas cover layers 8 which project beyond the supporting core 7 and of which one is folded over the front end at a right angle and the other one is guided loop like onto the other side of the front wall 20.
Also here the joining of the material takes place under the influence of heat and pressure.
At the van body 1 illustrated in Fig. 1 a flat part has been used which includes the two side walls 2 and 3, the top wall 4 and also the bottom 5. The; bottom is thereby completed of two half parts which are welded at the center in a thermoplastic manner such as is illustrated by the Figs. 4 to 6.By means of this a v,an body is formed which is practically integral in the direction of the circumference, whiich has homogeneous strength properties.
In order to mount a rear wall or a rear door a portion of the supporting core can be removed at the rear circumferentially extending end wall for obtaining a receiving groove, and a end profiled bar, for instance a squaxe tube made of aluminum or a plastic material set into the groove and mounted thereto. Hinges fo:r doors which consist preferably also of sandwich plates 6 can then be mounted to this end bas.
There exists, however, also the possibility that for producing a hinge between two walls of the van body which are to be pivotally connected (side walls 2 and 3 and wings of door) to provide these walls at their longitudinal edges which face ea~;,h other possibly with tubes set in at those edges and preferably welded in a thermoplastic manner into same, with recesses staggered in the longitudinal direction. The respective remaining edge portions of the other side engage into these recesses and than a hinge bolt can be stuck into the edges which mesh with each other.
As indicated in Fig. 1, the van body is connected by aid of screw bolt connections 30 to a supporting frame 32 of the motor vehicle which is depicted with broken lines. In the floor 5 condensed areas 31 (see also Fig. 14) produced by a deformation by heat are foreseen at the mounting area for forming joining points, each including a central hole 33 for receiving a screw bolt 34 extending there through. Due to the thermoplastic condensing at the connecting area the two cover layers S can be kept and are, therefore, included regarding the transmission of forces. This leads to a high stability at the connecting zone and a practically continuous transition of a flow of forces.
Material, which is located adjacent the condensed zone because it has been driven to that zone adds to mentioned fact. Fig. 14 does also depict that a interrnediate plate 41 for a distribution of forces is inserted between the bottom 5 and tile supporting frame 32 (of which only one single beam is illustrated). Condensed areas 'with cutouts formed in these areas can also be foreseen for the inserting of window:., hatches, doors or similar.
Fig. 10 and 11 illustrate a embodiment of a sandwich plate or flat part 9 formed from same. Two thermoplastic tubes 35 located at a distance frorr~ each other are placed here in the zone of foreseen folds which may be heated for a folding of the flat part. For this there is the possibility to temporarily place heating rods into the tubes for the folding operation. Furthermore, there is also the possibility to have heated air flowing through these tubes.
The inserted tubes 35 consist preferably also such as is the case of the other elements of the sandwich plate 6 of a thermoplastic material such that there is no detrimental effect regarding a recycling. For the folding process as such the flat part 9 can be, such as is shown in Fig. 11, placed onto a support 22 which has such dimensions, that the fold areas with the integrated tubes 35 come to rest at the longitudinal edges of the support 22.
Instead of a tube which is closed completely along its circumference, such as illustrated in Fig. 10 and 11 it is also possible to foresee in the zone of a intended fold a tube 36 which is slit at the inner side of the fold (fig. I2 and 13), whereby a heating wire 37 is inserted in at least one of the edges of the slit. The open dist2~nce between the edges of the slits corresponds in the not deformed state (Fig. 12) to about the foreseen angle of the fold and dimensioned such that at the foreseen angle of the fold the edges of the slit contact each other. In this position the heating wire is then a<;tivated and the edges of the slit weld together so that the tube is closed along its entire circumference, forms a stabilizing element and reinforces additionally the zone of the joint. Fig. 13 illustrates a flat part 9 and cut-out, respectively, of the van body which :has been formed under influence of heat and is reinforced by the welding together of the edges of the tubes.
It also shall be mentioned, that the tubes 35 illustrated in the Figs. 10 and 1 l and also the slit tube 36 illustrated in Fig. 12 and 13 can consist of a sandwich material.
The inserted tubes 35, 36 can also be used as installation tubes, for instance electrical conduits for the illumination system of the vehicle may be placed in these tubes.
At the inner side, at the side walls 2 and 3 of the van body, also a row of securing elements 38 for bracing belts 39 can be arranged such as can be seen in Fig.
1. These securing elements 38 consist of a roughly dish shaped supporting body consisting of a thermoplastic material which comprises at its concave side a transverse pin 40 arranged at a distance from the bottom of the supporting body and welded at its convex side to the inside to the side wall of the van body in a thermoplastic; manner. At the thermoplastic welding to the respective wall area of the van body the securing elements 38 are pressed somewhat into the wall which has softened after the heating.
Therefore, no additional mounting elements for a mounting of the securing elements 38 to the wall are needed. Hooks which are arranged at the end of the bracing belts 39 can be hooked on at the transverse pin 40.
It also shall be mentioned that directly with the producing of the sandwich plates or the flat part 9, respectively, consisting of such plate a outer protection layer is lacquered onto the plate which leads to a Long life time and a resistance against IJV-rays.

In summarizing, following advantages are arrived at, among others, by the present invention:
Simplification of the assembly and, thereby, considerable time savings;
no drilling and welding processes needed for assembling;
saving of weight down to 1/3 to 1/4 of previous weights and therewith a considerable higher cargo loading capabilit~i;
only one kind of material and therewith improved environmental compatibility;
extremely weather proof;
no sealing problems;
suitable in connection with foodstuff.

Claims

claims

1. Method for producing a box-type van body for transport vehicles, characterized in that a multi-layer flat part (9) consisting substantially of a thermoplastic material having a supporting core (7) and cover layers (8) located at both sides thereof of which the surface corresponds at least to two adjoining sides of the circumference of the van body (1) are heated at roughly linear zones which correspond to the borders of the edges of the adjoining circumferentially extending side walls (2, 3) of the van body (1) and are folded thereat.

2. Method according to claim 1, characterized in that a plurality of multi-layer sandwich plates (6) consisting substantially of a plastic material having a supporting core (7) and at both sides thereof cover layers (8) contacting each other at their narrow sides are joined in a thermoplastic manner to the flat part (9), that to this end at one of the end sides to be joined a portion of the supporting core is removed for forming a receiving groove (10) and from the end side of the other sandwich plate (6) a portion of the cover layers (8) is removed and the core zone is inserted into the receiving groove (10) and thereafter the two sandwich plates (6) are joined under the influence of pressure and heat.

3. Method according to claim 1 or 2, characterized in that at the mating zone of sandwich plates (6) or ends of flat parts abutting each other at the narrow sides, overlapping cover layers (8) are arranged and/or possibly additional material strips (18) of a thermoplastic material are laid thereon and that then the adjoining parts at the joining area are joined together under influence of heat and pressure and the area of the joint (14) is condensed corresponding to the thickness of the plate.

4. Method according to one of the claims 1 to 3, characterized in that at least all sides which are arranged in the circumferential direction of the van body (1) are part of the flat part (9) and in that after the folding of the sides the free ends which possibly face each other are joined at least under the influence of heat and preferably meshing with each other.

5. Method according to one of the claims 1 to 4, characterized in that in order to join a partial van body (1a) having in the direction of the circumference a angular or U-shaped or closed form to a wall extending at an angle and consisting of one or of a plurality of sandwich plates (6), a portion of the supporting core of one of the walls and a portion of the cover layers (8) of the other wall at the respective end zones are removed and that the cover layers (8) are connected in a thermoplastic manner overlapping the zone of the removed portion of the supporting core and at least the zone of the other wall without a cover layer.

6. Method according to one of the claims 1 to 5, characterized in that the wall foreseen to be joined to a partial van body (1a) and extending at an angle thereto is located roughly within the contour of the circumference of the partial van body (1).

7. Method according to one of the claims 1 to 6, characterized in that at least at one circumferentially extending end edge of a in the circumferential direction U-shaped or closed partial van body (1) a portion of the supporting core is removed and a closing off profile bar is inserted into this receiving groove (10) and joined thereto.

8. Method according to one of the claims 1 to 7, characterized in that in order to produce a hinge between walls of the van body (1) which are to be pivotally joined, they are given at their longitudinal edges facing each other recesses arranged staggered in the longitudinal direction, into which respective remaining edge portions of the other wall engage, and in that hinge bolts are stuck through the remaining edge portions of the meshing edges.

9. Method according to one of the claims 1 to 8, characterized in that a preferably thermoplastic tube (35, 36) is set into the flat part (9) at least at the area of a foreseen fold (25) (folding line), and for a bending of the flat part (9) the tube (35, 36) is heated and thereafter the folding is carried out.

10. Method according to one of the claims 1 to 9, characterized in that a thermoplastic tube is slit lengthwise and is equipped by at least one longitudinal edge with a heating wire (37), and in that thereafter the tube (36) is placed with the slit facing the inner side of the fold at the area of a foreseen fold (25) between adjoining walls into the flat part (9) or the sandwich plate(s) (6), respectively, and that thereafter during the thermoplastic bending the edges of the slits are placed against each other and thereafter welded together.

11. Box-type van body for transport vehicles which has adjoining walls, produced in accordance with one of the claims 1 to 10, characterized in that that walls (2 to 5 which adjoin each other at least in one circumferential direction of the van body (1a) and forming at least a angle- or U-shaped partial van body (1a) consist integrally of a in a thermoplastic manner formed flat part (9) having a supporting core (7) and outer cover layers (8), and in that the other edges thereof and possibly of further walls are connected together especially in a thermoplastic manner.

12. Van body according to claim 11, characterized in that the flat part (9) shaped in a thermoplastic manner to form the van body (1) or the partial van body (1) consists of a plurality of sandwich plates (6) joined in a thermoplastic manner.

13. Van body according to claim 11 or 12, characterized in that the joining zone of adjoining sandwich plates (6) is formed by slot and key like meshing edge sections of the sandwich plates (6), whereby the slot is formed by edge sections with a removed part of the supporting core at the one sandwich plate (6) and the key is formed at the section of the other sandwich plate (6) with a removed part of the cover layers, and in that the slots and keys are preferably dimensioned for a mutual overlapping.

14. Van body according to one of the claims 11 to 13, characterized in that walls of sandwich plates (6) of the van body (1) which adjoin each other at a corner area are joined by cover layers (8) of the one wall projecting beyond the edge of the supporting core (7) in a thermoplastic manner to the supporting core (7) and/or the cover layers (8) of the other wall in an overlapping manner.

15. Van body according to one of the claims 11 to 14, characterized in that the sandwich plate(s) (6) comprise(s) at the zone of their foreseen folds (25) between adjoining walls a tube (36, 36) as insert which fills preferably the distance between the cover layers (8) and consists specifically of a thermoplastic material.

16. Van body according to claim 15, characterized in that the thermoplastic tube inserted at the zone of a foreseen fold (25) between adjoining walls is slit longitudinally at the inner side of the fold and in that at least at one edge of the slit a heating wire (37) is inserted.

17. Van body according to claim 16, characterized in that the intermediate space between the edges of the slits corresponds in a not shaped initial state to the foreseen fold angle and is dimensioned in such a manner that the edges of the slits contact each other at the foreseen angle of the fold.

18. Van body according to one of the claims 15 to 17, characterized in that the tube (35,36) is a circumferentially closed circular tube or a slit rectangular tube preferably of a sandwich material.

19. Van body according to one of the claims 11 to 18, characterized in that mounting elements (38) with a roughly spherical segment shaped supporting body of a thermoplastic material are foreseen, that the supporting body includes at its concave side a transverse pin consisting preferably of steel and located at a distance from the bottom of the supporting body and joined by its convex side at the inside to a wall of the van body (1) in a thermoplastic manner and engages therewith at least at an of into the wall.

20. Van body according to claim 19, characterized in that the mounting bodies are located in rows at the inner sides of opposite walls of the van body (19).

21. Van body according to one of the claims 11 to 20, characterized in that the sandwich plates (6) have a core of a thermoplastic material which comprises either a thermoplastic honeycomb structure or consists of a thermoplastic foamed material, in that the core is joined to the cover layers (8) in a thermoplastic manner, in that the cover layers consist preferably of a reinforcing fabric with a thermoplastic material portion contained therein, and in that a outer layer of a thermoplastic material which at least can be varnished is laminated on to at least one cover layer in a thermoplastic manner.

22. Van body according to on of the claims 11 to 21, characterized in that the cover layers (8) consist of a reinforcing fabric, for instance of glass, a carbon material or similar with fibers of a thermoplastic material distributed in same, or of a thermoplastic material with a reinforcing fabric melted into same and/or a reinforcing fabric with a thermoplastic coating.

23. Van body according to claim 21 or 22, characterized in that the honeycomb or foamed material supporting core (7) and preferably also the thermoplastic material portion of the cover layers (8) consist of Polypropylene (PP) and outer layers (s) (8) consisting of Polycarbonate (PC), Polymethylmethacrylate (PMMA) or similar material which can be varnished are possibly arranged on the cover layers.

24. Van body according to one of the claims 11 to 23, characterized in that the sandwich plate(s) (6) comprises one or a plurality of condensed zones (31) produced by a hot forming as joining points for joining sandwich plates (6) together and/or for a joining to other parts and that in these joining zones (31) the cover layers (8) feature in relation to their initial position at a mutual distance due to the supporting core (7) a condensed position with a at least decreased distance.

25. Van body according to claim 24, characterized in that at or adjacent the condensed zone (31) of the sandwich plate (6) supporting core material is located which has been forced away during the heat shaping.

26. Van body according to claim 24 or 25, characterized in that inside of the sandwich plate (6) a condensed zone (31), possibly with a cut out for instance for a window, a hatch, a door or similar is foreseen.

27. Device for practicing the method according to one of the claims I to 10 as well as for producing a van body (1) according to one or several of the claims 11 to 26, with a support (22) for a flat part (9) consisting of a sandwich plate (6) comprising a multi-layer flat part (9) consisting substantially of a thermoplastic material having a supporting core (7) and cover layers (8) located at both sides thereof, which support (22) has by at least one of its edges a heating zone, characterized in that for a heating a sandwich plate (6) or similar equipped with tubes (35, 36) at the folding zones a heating bar is foreseen which can be temporarily inserted into the tube.

28. Device according to claim 27, characterized in that it comprises for a joining of flat part edges or sandwich plates (6) which adjoin each other at narrow sides a pressing device (11) with pressure pads (12) which can be heated and/or pressure rollers which can be heated and pressed on preferably at both sides at opposite areas of the zone of the junction (14) of sandwich plates (6) or flat parts (9).