WO2008058765A1

WO2008058765A1 - Multi-part component, in particular a multi-part heat shield

Info

Publication number: WO2008058765A1
Application number: PCT/EP2007/009989
Authority: WO
Inventors: Jutta Reiss; Martin Wuchenauer
Original assignee: Reinz-Dichtungs-Gmbh
Priority date: 2006-11-17
Filing date: 2007-11-19
Publication date: 2008-05-22
Also published as: EP1923577B1; EP1923577A1; DE502006003902D1

Abstract

The invention relates to a multi-part component (1) in which at least one of the parts (2,3) is a laminar shielding part for shielding an object from temperature and/or noise, which is joined to at least one other part in that in the first one of the parts (2,3) at least one tab (4) is provided, which is connected on one side (41) with the part and the free end (42) of which projects over one of the surfaces (21) of the first part (2) in the direction of the second part (3). The tab (4) comes to rest on one surface (31) of the second part and the sections (22,23) of the first part (2) laterally adjacent to the free end (42) of the tab (4) come to rest on the opposing surface (32) of the second part (3), clamping the second part (3) between them.

Description

MULTI-PART COMPONENT, IN PARTICULAR A MULTI-PART HEAT SHIELD

[0001 ] The invention relates to a multi-part component, in which at least one of the parts is a laminar shielding part for shielding an object from temperature and/or noise. Laminar shielding parts of this kind are generally known as heat shields and are employed for instance in the engine compartments of motor vehicles, inter alia in the region of the exhaust system, to protect adjacent temperature sensitive components and assemblies against excessive heat. These heat shields often also serve as soundproofing at the same time. Specifically, such heat shields can for instance be employed to shield a catalytic converter or primary catalytic converter, a diesel particulate filter or other components in the area of the exhaust gas pipe or a turbocharger.

[0002] To save space, components installed in engine compartments are often nested within each other to a high degree. Consequently, there is often very little space available for the heat shield and it must often be of a three dimensional shape in order for it to follow the contour of the component being shielded as closely as possible. The resultant highly complex three-dimensional design of many heat shields leads to problems with respect to their manufacture. If possible, heat shields are stamped or deep drawn into the desired three-dimensional shape from an initially flat, layered structure by means of a suitable stamping tool or punch. However, in the case of structures subject to extreme three-dimensional deformation this is generally no longer possible as for instance fissures appear in the layered structure as a result of excessive deformation. Heat shields with extreme projections and recesses or undercuts cannot be manufactured in one piece anyway using a stamping tool or punch as in such cases demoulding is no longer possible. For this reason, extreme three dimensionally shaped heat shields are as a rule assembled from a number of parts that are each manufactured separately.

[0003] Various options are known according to the state of the art for assembling the parts of a multi-part heat shield. For example, the parts are manufactured in such a way that they overlap in an area with a screw fastening and are connected to each other by being screwed together in this overlapping section. It is also known for two parts of a heat shield to be joined together by means of a hinge. It is also common for parts of a heat shield to be fastened to each other by means of clips. One example of this is described in DE 102004030622 A1.

[0004] However, a disadvantage of these options is that connecting the parts of the heat shields is relatively costly and additional fasteners such as hinges or connecting clips are often required. In cases where the parts of a heat shield are screwed together, the individual parts must be handled separately and individually placed around the object being shielded until they can be joined together to form the finished heat shield by means of a common screwed connection. However, fastening the individual parts of a heat shield is more complicated and awkward than attaching a heat shield that has already been assembled.

[0005] Accordingly, the o b j e c t of the invention is to disclose a multi-part component in which at least one of the parts is a laminar shielding part to shield an object from temperature and/or noise which can be assembled in a simple manner before it is attached in the area of the object being shielded or during such attachment and which does not involve the use of separate fasteners if possible.

[0006] This object is fulfilled by means of the multi-part component in accordance with Claim 1. Preferred embodiments are described in the dependent claims.

[0007] Therefore, the invention relates to a multi-part component in which at least one of the parts is a laminar shielding part to shield an object from temperature and/or noise. It is connected with at least one other part by means of at least one tab developed in the first part, with the tab connected to this part on one side and its free end projecting in the direction of the second part above one of the surfaces of the first part. The tab is developed in such a manner that it comes to rest on one of the surfaces of the second part, while the sections of the first part laterally adjacent to the free end of the tab come to rest on the opposing surface of the second part such that the second part is clamped between the tab and the laterally adjacent sections.

[0008] Thus, the second part is held in the first part in a force fit, to be exact between the tab and the sections adjacent to the tab of the first part. The adjacent sections can be present on one or preferably on both long sides of the free end of the tab and together with the tab form a yoke-like mount. No further fasteners are required to fasten the two parts to each other. Consequently, clamps or the like that are separate from the parts are not required. However, if desired, they can be used in a supplementary manner in order to provide additional strength to the insertion joint. Similarly, it is possible to strengthen the insertion joint by means of fasteners known in the state of the art, i.e. for example by means of welding, soldering, riveting, clinching, adhesive bonding. Moreover, the parts can be connected to each other prior to installation, something which facilitates installation considerably, for instance in an internal combustion engine compartment. However, this does not rule out that the multi-part component in accordance with the invention is installed in a known manner per se such that the parts are fastened additionally to each other by means of a common fastener, that is for instance fastened by means of a common screwed connection. On the other hand, fastening the parts to each other is easily possible. Consequently, fitting together can be undertaken very easily just before final assembly, which means that the more easily transported individual parts can be delivered, rather than the unwieldy finished component. Similarly, it is possible to fit the parts together during final installation, for example, when the parts encompass and enclose a part located between them from opposing sides.

[0009] Preferably, both parts of the multi-part component are connected to each other in a form- fitting manner. Advantageously, the first and the second part overlap across the entire border area and bear against each other directly in a form fitting manner. This has the advantage that production tolerances in the cut of the parts can be neutralised by the overlapping. [0010] In accordance with the invention, the multi-part component is provided with one part which is a laminar shielding part for shielding an object from temperature and/or noise. This part can be a partial section of a heat shield that is connected with one or a plurality of other partial sections of the heat shield or other components. However, the part can also be a complete heat shield that is fitted together in accordance with the invention in a form fitting manner by means of one or a plurality of tabs with another component that does not belong to that heat shield per se, but which is designed to be connected to it. This part to be fastened to the heat shield can for instance be a further heat shield for shielding another object or another mounted part such as for instance a mounting support for fastening another part to the heat shield, a bracket for the heat shield etc. Fastening by means of a tab-insertion joint also makes it possible to produce very complex three-dimensional structures in a simple way without additional fasteners, structures that cannot be achieved with a one-piece component. Basically, the number, shape and size of the parts is unlimited. If more than two parts are used, only two of the same can be fastened by means of a tab-insertion joint or more than two. As the construction of the multi-part component in accordance with the invention is simple, it seems natural to manufacture complex heat shields with a modular design. For instance, a part - preferably one without complex three-dimensional geometry - is manufactured such that it can be used for different heat shields and is then inserted together with other parts that are model specific to form a multi-part component in accordance with the invention. [0011] With respect to the connection of the parts to form the multi-part component in accordance with the invention, it does not matter on which of the parts the at least one tab for creating the insertion joint is located. The at least one tab can be developed on either the shielding part or on another part. It is also possible to make provision for tabs not only on the shielding part, but also on the part to be connected to the shielding part. Accordingly, each respective other part is provided with a complimentary mounting section which is clamped between the tab and the areas adjacent to the free end of the tab or in the case of a tab at the corner of a part, the area adjacent to the free end of the tab. Provision can be made for the at least one tab to be either near the edges of the first part or in the middle section of the first part. Combinations of both variants are also feasible. If the at least one tab is located near the edge of the first part, it is produced advantageously by providing two cuts or recesses running inward from the edge of the first part, forming the lateral boundaries of the tab. Consequently, the free front end of the tab constitutes a section of the outer edge of the first part. Such a tab located in the outer edge section of the first part is eminently suitable for holding a section of the outer edge of the second part in a force fit. However, due to its position, sometimes a lateral free end of the tab is also predestined to hold the corresponding section of the outer edge of the second part in a force fit.

[0012] Alternatively or in a supplementary manner, the tab can also be developed in the central area of the first part. To do so, the tab must then also be separated from the first part at the leading edge of the tab's free end, so that it is just connected with the part on only one side. In this case as well, the tab can be used to clamp an outer edge of the second part. However, it is preferable in this case for the tab to be inserted through a through-hole in the second part, developing an insertion joint. Of course, a through-hole in the second part can also be used to fasten a tab developed near the edge of the first part. When using a through-hole for inserting the tab, it is highly preferable to develop the through-hole such that when the tab is inserted through it, the tab essentially fits exactly between the sides of the opening. In this case, the through-hole can also serve to centre the first and second part with respect to each other.

[0013] Fastening the tab in a through-hole must also be understood to include a case where the tab is inserted through a bar protruding from one of the surfaces of the second part. In these cases, the tab also fits closely with a section on one of the surfaces of the second part and with another section on its opposing surface. The bar may only be fastened at one end of the part, but it is preferable for it to be developed in a bridge-like manner, being held firmly with both lateral ends on the second part. [0014] In order to be able to clamp the second part securely between the tab and the sections adjacent to the free end of the tab, the tab is advantageously only formed out so far over a surface of the first part that the second part with its mounting area can just be accommodated under tension in the space formed. Preferably, the free end of the tab is shaped such that essentially it runs parallel to the clamped surface of the second part. Furthermore, it can be advantageous if additional measures are taken to increase the clamping tension and to secure the attachment of the first and second part to each other.

A first option involves for example provision being made in the region of the lab joint for a locking means in order to develop a locking joint between the first and second part. To this end, provision is made in a known manner per se for an arresting projection and a corresponding arresting recess. In this case it is principally irrelevant whether the arresting projection is located in the first or second part and inversely, the arresting recess is in the second or first part. In the first part, provision can be made for the locking joint to be either in one or both of the regions adjacent to the tab and/or on the tab itself. The latter is preferred as the tab will already have certain resilient qualities itself owing to its design, which facilitate the development of the locking joint.

[0015] The clamping tension can also be increased by providing the tab with at least one elastic member. Imminently suitable in this case is a bead that increases the clamping tension with which the tab is pressed onto the second part. Alternatively, more compact geometries are possible, e.g. round or oval elevations with a flat or domed surface. A plurality of elastic members can also be provided on the tab one after the other along a longitudinal axis. One advantage of such a development lies in an increase in the flexibility of the tab, which allows it to accommodate the other part better and can compensate movements impacting upon the multi-part component. In addition, the development of the tabs can produce a topography. For example, the height of the elastic members can change along the longitudinal axis of the tab. For example, it can be expedient to increase the height of a bead or another elastic member in the direction of the free end in order to maintain high clamping tension along the full length of the tab. If desired, the elastic member can also serve simultaneously as an arresting projection to develop the aforementioned locking joint. A depression or a recess in the second part or an area behind a dome, for example in the form of a bead, can for instance serve as an arresting depression behind which the arresting projection of the first part locks into place. Essentially it is also possible for the elastic member to be solely in the second part and not on the tab. However, at present this is not preferred as it is simpler to press the bead or any other elevation forming the elastic member at the same time as the tab is punched from the planar surface of the first part. [0016] In order to simplify joining the parts with an exact fit, provision is made advantageously for at least one centering mechanism in the area of the insertion joint. Preferably, a plurality of centering mechanisms are provided for each pair of inserted parts, a situation that can be achieved either by having one centering mechanism in each case in the area of one of a plurality of tabs or a plurality of centering mechanisms for each inserted lap joint. The centering mechanism can be developed in a known manner per se by means of complimentary guide members in the first and second part. Reference has already been made to the option of developing a tab in the first part to fit perfectly into a through-hole in the second part. The above-mentioned locking joints can be developed in such a way that they serve as a centering mechanism at the same time. Similarly, the elastic members can be developed in such a way that they align the parts with respect to each other. For example, a stiffening bead can extend longitudinally along the tab and it is pushed onto a complimentary bead in the second part when the parts are fitted together. The outer contour of the tab itself can also be used as a guiding member, for example with a longitudinal edge section of the tab coming to rest on a complimentary outer edge section of the second part after the parts are fitted together.

[0017] The number, shape and size (length, width, thickness) of the tabs can essentially be arbitrary and be selected for instance according to the requirements with respect to the stability of the joint. Preferably, 1 to 15 tabs, in particular 1 to 5 tabs, are used for connecting two parts. In the simplest embodiments, the tab is rectangular or lingular. However, more complicated shapes can also be chosen if the tab is intended to assume for instance the centering function or the parts are to be prevented from sliding apart too easily. The development of special outer contours, projections and elastic members on the surfaces has already been mentioned. The various tabs on a part can be designed very differently in this respect. The tabs are mostly only deformed slightly in order to provide the requisite gap for inserting the other part. However, if the parts are considerably deformed three dimensionally, the tabs can be formed out of their original plane in order to facilitate fitting together with a curved complimentary part. In this case, the bending of different consecutive tabs, for instance along the outer edge of this edge, can vary in the same way as the aforementioned qualities of the tabs, i.e. shape, length, width and thickness as a function of the curvature of the complimentary part. It is also possible to make provision for one or a plurality of sections in the area of the tab to be deformed after the parts have been fitted together. Such a development serves the primary purpose of preventing the parts from sliding apart. Provision can be made for instance for deformable sections in the leading edge section of the free end of the tab. In a preferred variant of the invention, they are inserted with the free end of the tab through a through-hole in the second part and then bent so that they project laterally over the through- hole and can no longer be retracted through it. A similar effect could also be achieved by caulking the edge sections of the tab.

[0018] Not only an edge section or a through-hole of the second part can serve to fasten the tab of the first part to the second part, but a tab can also be used that is developed essentially in the same manner as that in the first part. For example, two tabs with their leading free ends opposing each other can be pushed one after the other. Alternatively or additionally, opposing tabs can be inserted into each other. Opposing means that the tabs are essentially bent to be U or V shaped and the frontal ends of the tabs face away from each other. If desired, in addition the tabs can be interlocked by deforming them after being fitted together. Furthermore, one or both of the tabs fitted together can be provided with deformable sections which fasten the tabs to each other after bending as described. The tabs can be attached in the edge sections of the first or second part and/or their inner section.

[0019] In addition to clamping another part, the free ends of the tabs can also serve to fasten further members. If of sufficient length, they can for instance be used for guiding cables. In addition, they can serve to accommodate a threaded connection or similar fastener in order to connect other components to the tab.

[0020] In most cases, only one further part is encompassed with a particular tab. However, it is also possible to insert a plurality of parts, in particular two, between one tab and its adjacent sections, with the aforementioned two parts lying on top of each other in the region of the tab. In this case, in order to increase stability it is preferred when the two aforementioned parts are fixed to each other by means of the aforementioned elastic members.

[0021 ] In order to facilitate fitting the parts together and to prevent friction between the multi-part components following their installation, provision can be made for a sliding member between the parts at least in the joint area. For example, it can involve a per se known anti-friction coating on one or both of the connected parts. Additionally or alternatively, a damping member can be inserted into the described area in order to absorb the movement of the parts against each other. Suitable damping members are elastomer buffers made of synthetic material, spring members made of metal or other suitable materials. An anti-friction coating can also assume an additional damping function. In a similar manner, sealing members, also additionally or alternatively, can be inserted for instance in the form of temperature resistant chords, beads or strips.

[0022] The parts connected by means of inserted lap joints can consist of any arbitrary material. Different materials such as metal, synthetics, fibre materials etc. can also be combined. The part which serves to shield against heat and/or noise consists advantageously of materials already used previously for heat shields. These are often individual metal sheets or multi-layered materials with two metallic surface layers and in certain cases an insulating layer embedded between these.

[0023] Thus, as is known from the state of the art, heat shields on the one hand can be constructed from only one - especially metallic - layer, which then preferably has some surface structuring in order to increase e.g. its stiffness or its shielding properties. In order to provide sufficient stability to the tab, it is preferable if this structure is not present in the tab but only the round or oval elevations etc. mentioned above with respect to some embodiments of the invention. The mounting area in the second part can either be structured or unstructured, the latter facilitating the attachment of the tab, the former preventing its sliding back.

[0024] On the other hand, several multi-layer constructions are known for head shields, they can e.g. be constructed from two metallic layers. Structuring of one or both of these layers is known from the state of the art as well. Heat insulation of such two-layer constructions can be improved with an air gap between the two layers or with a further insulating layer between the two metallic layers. The insulating layer comprises mica, temperature-stable paper, inorganic or organic fiber composite materials, or other suitable insulation materials, for example. The outer edges - as well as some through-openings - of the two-layer constructions - with or without an insulation layer - can be designed in such a way that they are flush in both metallic layers with the layers connected to each other by welding along the outer edge. An insulating layer, if present, preferably does not reach into the welding area. In an alternative embodiment, and this is preferred especially with particulate insulating layers, the outer contour of one of the layers (layer A) is larger than the other one (layer B) in order to be hemmed around the outer edge of the other layer. Here, the insulating layer may extend as far as the smaller layer, i.e., layer B, but not further. Thus, it is not hemmed around another layer.

[0025] In case the two metallic layers are connected without a hem, a tab may be formed in a comparable manner as in a one-layered part, with the tab protruding from the outer edge of the respective layer either in only one or in both layers. For two-layered tabs, it is preferred if the two layers are either welded together also within the extension forming the tab or linked by a corrugation which is simultaneously coined into both layers, e.g. a bead. A welding line connecting the two layers along the outer edge of the part in general can be continued by crossing the protrusion^) forming the tab without taking selective measures. [0026] For outer edges with a hem, the situation is not that straightforward. On the one hand, it is possible that a through-opening is formed in the bending area of the hem in layer A and a protrusion forming the tab in layer B is guided through this hole before the actual hem is folded over. If several tabs are to be provided, the protrusions need to be in perfect parallel alignment to avoid the disadvantages of too large through-openings. Moreover, it is not possible to arrange tabs on more than one lateral edge of a part in this way. Therefore, it is preferred to provide a recess in the complete bending area of the hem in layer A with a width slightly wider than the width of the protrusion forming the tab. Since the hem still encompasses most of the outer edge of layer B, this provides sufficient connection between the two layers. Areas of the edge, in which the hem shows either a through-opening or a recess, may be reinforced by any linear corrugation, e.g. a bead, which is preferably pressed-in simultaneously with bending over of the hem. This is especially advantageous for particulate insulating layers.

[0027] A multi-layered second part provides several opportunities to design the mounting area(s). With moderate layer thicknesses, coining as for one-layered solutions is possible as well. If there is an insulating layer, in particular a particulate insulating layer, it can be partially dispensed with in the mounting area of the second part. Advantageously, this is performed such that an area is free of the insulating layer between the metallic surface layers that is large enough to accommodate the tab of the first part. Therefore, the tab is inserted between the surface layers, while the lateral sections adjacent to the free end of the tab come to rest on the other side of one of the insulating layers such that one of the surface layers is clamped between the tab and the lateral areas. If there is no insulating layer, it is also possible to cut out one layer in the area to accommodate the tab. In principle, if several tabs with a distance relative to each other are to be accommodated, this can be done by providing such cut-outs alternately on the two layers leaving a two-layered intermediate area between two such cut-out areas.

[0028] The manufacture of the at least one tab can be integrated into the conventional manufacturing steps in a simple manner. Punching the tab free can be done for instance at the same time as the openings in a heat shield pre-form are punched and/or the pre-form is punched out. The tab can be formed and if required the elastic members, arresting projections etc. can be formed at the same time as the three-dimensional structure is embossed or deep drawn from the planar base material.

[0029] The invention is described below with reference to some drawing. The following figures, in which the same reference symbols designate the same parts, are purely schematic and serve solely to illustrate some preferred examples, without restricting the invention to these. Fig. 1 shows a partial top plan view of a first embodiment of a multi-part component in accordance with the invention with reference to an example of a heat shield in a non-assembled and an assembled state.

Figs. 2 to 11 show partial top plan views of further embodiments of a multi-part component in accordance with the invention with reference to an example of a heat shield in a non-assembled and assembled state,

Figs. 12 to 14 show further embodiments of the first part of the multi-part component according to the invention, all of them being two- or multi-layered

Figs. 15 and 16 show further embodiments of the second part of the multi-part component according to the invention and

Fig. 17 shows a perspective view of a multi-part component in accordance with the invention with reference to an example of a heat shield.

[0030] Figures 1 to 16 show sections of a multi-part component in accordance with the invention, namely a heat shield for installation in the engine compartment of a motor vehicle, such as the example shown in Figure 17. The heat shield 1 is assembled from a plurality of parts 2 and 3, with part 3 in the drawing covering a front left-hand section of the curved part 2 and standing essentially perpendicular in relation to it. The parts 2 and 3 each consist of a metal layer or a multi- layered structure that has been given the three dimensional form shown by means of embossing or deep drawing.

[0031] The parts 2 and 3 are connected to each other by means of insertion joints in the areas marked with the letter A (see Fig. 17). These joint areas are shown in detail in Figures 2 to 11.

[0032] Fig. 1 shows a joint at the edge of parts 2 and 3. The tab 4, developed in the first part 2, is therefore only bordered at its free end 42 on the left by a lateral section 22. The tab 4 is only still connected on one side 41 with the part 2 and is developed as a rectangle. Its free end 42 projects over the surface 21 of the part 2 and extends essentially parallel to the surface 21, apart from the area of bending directly adjacent to the connecting edge 41. A yoke-like mounting section is formed by upturning the tab 4 into which an edge section 33 of the second part 3 can be inserted. The gap between the end of the tab 42 and the surface 21 is of such magnitude that the edge section 33 can be clamped in this area and held under tension there. The left-hand part of Fig. 1 shows the situation before parts 2 and 3 are fitted together, while the right-hand part shows the assembled parts. The edge sections 33 and 22 of the parts overlap after the parts are fitted together. The lateral section 22 comes to rest on the surface 32 of the part 3, on the other hand the free end of the tab 42 rests on the surface 31 such that a section of the part 3 is clamped between them in a yoke-like fashion. This results in a form-fitting joint that manages without additional fasteners.

[0033] The joint in Fig. 2 corresponds essentially to that in Fig. 1. However, the tab 4 is located between two lateral sections 22 and 23 of the first part 2, from which it is separated by means of bilateral cuts 25 extending from the outer edge 24 toward the centre. Furthermore, the surface 33 is provided with an anti-friction layer 7.

[0034] The difference between the embodiments in Figures 2 and 3 lies in the manner in which the tab 4 has been separated. Instead of the cuts 25, there are recesses 26 in Fig. 3, creating a lateral gap between the end of the tab 42 and the sections 22 and 23. In this manner, friction between both parts is prevented when the tab 4 is pressed out of the part 2.

[0035] In the embodiment in accordance with Fig. 4, in contrast to the tab 4 in Fig. 2, it is provided with a bead 6 extending longitudinally across the tab 4 and the adjacent section of the part 2. The bead 6 increases the stability of the tab 4 and increases the contact pressure with which this presses on the part 3.

[0036] In Fig. 5 the bead 6 serves not only to strengthen the tab 4, but also at the same time to act a guiding member as part of a centering device 8. In a complimentary manner to bead 6, a further bead 6 is impressed into the edge section 33 of the part 3. Furthermore, there are further beads 6' of this kind on either side of this bead 6. When the parts 2 and 3 are inserted into each other, the matching beads 6 (or 6') are pressed onto each other, centering the parts 2 and 3 with respect to each other in the desired position.

[0037] Fig. 6 shows a form of joint where the free end 42 of the tab 4 is not oriented toward the outer edge of the part 2, but is arranged in the inside of the part 2 and the free end 42 points away from the outer edge of the part. There is a through-hole 34 in the second part 3 for accommodating the free end 42 of the tab 4, with said through-hole being just large enough for the free end 42 to be inserted through it. In this way, the arrangement also serves the lateral orientation of the parts 2 and 3 with respect to each other.

[0038] In Fig. 7 the free end 42 of the tab 4 is once again oriented toward the outer edge of the part 2. In contrast with the embodiment in accordance with Fig. 2, the front section of the free end 42 is provided with a bead 6 extending transversely across the tab 4. This bead 6 snaps into a recess 51 extending parallel to the outer edge of the part 3, developing a locking joint 5 with it. The locking joint could also employ a recess instead of the recess 51, in which case the bead 6 is preferably at a greater distance from the free end 42 of the tab 4.

[0039] Fig. 8 shows an especially stable joint. The joint is maintained by the presence of projections 44, 45 near the leading edge section of the free end of the tab 4. In the unassembled state of the parts 2 and 3, the projections 44, 45 are bent upward away from the part 2 to such a degree that the free end of the tab 4 can be pushed through the opening 34. Then, the inserted section 43 is deformed such that it cannot be pulled out of the through-hole 34 any more. This is achieved by bending the projections 44 and 45 downward in the direction of the second part 3 until they extend essentially along one plane with the remaining free end of the tab 4. While Figure 8 shows an embodiment in which the second part 3 is not provided with a tab, in principle it is also possible for the section of the part 3 in which the through-hole 34 is developed and the frame surrounding this through-hole to also be developed as a tab, which preferably is separated from the part 3 on two sides.

[0040] Fig. 9 shows a variant of the clamping joint from Figure 2, with both parts 2 and 3 provided with tabs 4 and 4¹. Once again, these are separated from their lateral sections 22, 23 and 37, 38 by means of recesses 26 and 36. The tabs 4 and 4¹ are provided with connecting sections 41, 41', each of which is provided with a step. The depiction of the assembled component shows that the tabs 4 and 4' not only overlap reciprocally, but also part of the surfaces 31 and 27 of the other part respectively.

[0041 ] Figure 10 shows an embodiment in which a sealing strip 9 made of a temperature- stabilised material, e.g. a fibrous material, is held between the two parts 2 and 3 when the parts are fitted together. In the example shown, the flat ceiling strip 9 lies between the tab 42 and the laterally adjacent sections 22 and 23. The sealing strip is provided with a width that is suitable for sealing the openings of the recesses 26 which would otherwise remain open after the two parts 2 and 3 are fitted together. This can for instance prevent a chimney effect, i.e. the rise of hot air, such that the shielding function is not interrupted locally.

[0042] The embodiment given in Figure 11 is distinguished from the one given in Figure 3 by both the first and the second part 2 and 3 being two-layered. Some reference numerals are omitted for clearness reasons. The second part 3 shows a welding line 305 connecting the two parts along its outer edge 304. The first part 2 shows a tab 4 which is only one-layered and protrudes from the upper layer 200. The lower layer 201 does not reach into the area of the tab, but is folded back with a hem 202. The two layers of the hem 202 are linked to the upper layer 200 by a bead 203 which ranges from the upper layer 200 through the folded section of the lower layer 201. In the area depicted, the upper layer 200 apart from the recesses 26 protrudes further than the lower layer 201. When the two parts are connected, the lateral edge sections 22 and 23 come to rest on the lower side, thus the lower layer 301 of the second part 3, while the actual tab 4 rests on the upper layer 300.

[0043] Figures 12 to 14 indicate further embodiments for multi-layered first parts 2. Figure 12 demonstrates how the tab 4 may extend from the upper layer 200 of part 1. The lower layer 201 is bent around the edge of the upper layer 200 with the exception of the protrusion forming the tab 4. Figure 13 depicts an embodiment in which the lower layer 201 contains a through-opening 207 through which the tab 4 is inserted before the hem 202 is folded over. In order to stabilize the area or in order to prevent particulate insulation material to crumble through the through- opening 207, a bead 209 is coined into the folded-back portion attaching the layers to each other. Such a bead is feasible in other embodiments as well. Both in the embodiment of Figure 12 and 13 further tabs might be arranged in the continuation of the outer edge.

[0044] Figure 14 shows an embodiment of a first part 2 with a two-layered tab 4 and two-layered lateral edge sections 22 and 23. In the tab area, the two layers 200 and 201 are connected to each other by welding. On the example of the lateral edge section 23, it is shown that single welding points 220 may be sufficient for the connection. The two layers of other lateral edge section 22 are linked by a welding line 210 which runs in parallel to its edge. On the example of the tab 4 itself, it is demonstrated that these two manners of welding may be combined, too. One may also think of a welding line running along all cutting edges. The choice of the connection manner will depend on the stiffness and/or resilience required in the tab and the lateral edge sections. Two-layered tabs of course can also show corrugations or guiding structures such as for instance presented on the examples of Figures 4, 5 and 7.

[0045] Figure 15 shows a two-layered second part 3. Two admission areas 310 and 311 for admitting tabs with corrugations are present near the edge 340. Both admission areas 310 and 311 are formed by through-holes in the upper and lower layer 300 and 301, respectively. For stability reasons, it is preferred that a sufficiently wide transition region 315 in which both layers 300 and 301 are present is given between these through holes. In the same way as with through-holes in the upper or lower layer, admission areas might be formed by leaving out the insulating layer in regions. [0046] Figure 16 finally demonstrates with a planar view and two sectional views of the edge of a second part 3 how a hem 302 can be used to design admission areas 310 for admitting tabs 4 by varying the height of the hem 302 along the outer edge 304 of the second part 3. While in the upper sectional view, the height of the hem 302 corresponds only to the general height of the part 3, so that no resistance against sliding back of a tab 4 is constituted, the height of the hem 302 in the lower sectional view is increased by imbedding the upper layer 300. A bead in a tab 4 (see for instance bead 6 in Fig. 7) can be admitted by this thickened hem area without the danger of its sliding back.

Claims

LANG & TOMERIUS FRIEDRICH LANCB ava r i a r i n g 29 . „ . . , ,_ ° , Lang@patented .dePatentanwalte D-80336 Mϋnchen b vEuropean Patent Attorneys TeI. 089-54369960 DR. ISABEL TOMERIUSEuro Trademark Attorneys Fax 089-54369970 Tomerius@patented.deReinz-Dichtungs-GmbHR.P 710 WOTO/peCLAIMS

1. Multi-part component (1), in which at least one of the parts (2, 3) is a laminar shielding part for shielding an object from temperature and/or noise, which is joined to at least one other part in that in the first one of the parts (2, 3) at least one tab (4) is provided, which is connected on one side (41) with the part and that its free end (42) projects over one of the surfaces (21) of the first part (2) in the direction of the second part (3), with the tab (4) coming to rest on one surface (31) of the second part and the sections (22, 23) of the first part (2) laterally adjacent to the free end (42) of the tab (4) coming to rest on the opposing surface (32) of the second part (3), clamping the second part (3) between them.

2. Multi-part component in accordance with Claim 1, wherein the at least one tab (4) is bordered by two cuts (25) or recesses (26) extending from one outer edge (24) of the first part (2) into its interior.

3. Multi-part component in accordance with Claim 1, wherein the at least one tab (4) is provided in the interior of the first part (2).

4. Multi-part component in accordance with any one of the previous claims, wherein the at least one tab (4) and the laterally adjacent sections (22, 23) clamp an outer edge section (33) of the second part (3) between them.

5. Multi-part component in accordance with any one of Claims 1 to 3, wherein a through-hole (34) is provided in the second part (3), through which the tab (4) is to be inserted.

6. Multi-part component in accordance with Claim 5, wherein the section (43) of the tab (4) inserted through the through-hole (34) is deformed in order to prevent the tab (4) from sliding out of the through-hole (34).

7. Multi-part component in accordance with any one of the previous claims, wherein provision is made for an arresting facility in the region of the tab (4) to develop a locking joint (5) between the first and second part (2, 3).

8. Multi-part component in accordance with any one of the previous claims, wherein provision is made in the area of the tab (4) and/or the laterally adjacent sections (22, 23) for at least one centering device (8) for aligning the parts (2, 3) in a desired position in relation to each other.

9. Multi-part component in accordance with any one of the previous claims, wherein the tab (4) is provided with at least one elastic member, in particular a bead (6).

10. Multi-part component in accordance with any one of the previous claims, wherein at least one tab (4') is provided in the second part (3).

11. Multi-part component in accordance with Claim 10, wherein one tab (4) of the first part (2) is hooked into one tab (4¹) of the second part (3) in each case.

12. Multi-part component in accordance with Claim 11, wherein the tabs are interlocked by means of deformation.

13. Multi-part component in accordance with any one of the previous claims, wherein at least in sections a sliding (7), sealing (9) and/or damping member is embedded in the joint area between the first and second part (2, 3).

14. Multi-part component in accordance with any one of the previous claims, wherein the parts (2, 3) constitute different sections of a heat shield.

15. Multi-part component in accordance with any one of the previous claims, wherein at least one of the parts (2, 3) comprises at least two metal layers.

16. Multi-part component in accordance with claim 15, wherein the at least one part (2, 3) at least in regions comprises an insulation layer between the two metal layers, with the insulation layer preferably comprising mica, temperature-stable paper, inorganic or organic fiber composite materials.

17. Multi-part component in accordance with one of claims 15 or 16, wherein the two metal layers of the at least one part (2, 3) are connected to each other at least in their edge region, with the connection preferably achieved by folding over into a hem (202) and/or welding.

18. Multi-part component in accordance with one of claims 15 to 17, wherein the hem (202) is formed in such a way that the tab (4) protrudes through a trough-opening (207) in the hem (202).

19. Multi-part component in accordance with one of claims 15 to 17, wherein the hem (202) is formed in such a way that it is discontinued in the region of the tab (4).

20. Multi-part component in accordance with one of claims 15 or 16, wherein at least one admission area (310, 311) for a tab (4) is formed by locally cutting out at least one of the metal layers (300, 301) or the insulation layer.

21. Multi-part component in accordance with one of claims 15 or 16, wherein at least one admission area (310) for a tab (4) is formed by locally increasing the thickness of the hem (302), preferably by imbedding in sections the edge of the other metallic layer or of the insulation layer in the hem (302).