Glazing perspectives. at the Frankfurt Motor Show 1997 (second part) Automotive glazing

Transcription

1 Automotive glazing Glazing perspectives at the Frankfurt Motor Show 1997 (second part) The second part of the report on the main demands on automotive glazing from designers and car makers at the Frankfurt Motor Show 1997 assesses the consequences of increasingly complex shape and all round visibility for sunroofs and transparent roofs. The author also reports on glazing solutions for mirrors, plastic lenses and navigation display systems. The first part, published in issue 1/98, looked at the implications of the above trends for rear and side windows and windscreens. The consequent safety and comfort requirements for IR absorbing glass, IR reflecting glass, as well as stronger impact and break resistance, were also examined, together with the implications of the increased use of ergonomic colour inside the car. Giovanni Manfré* MG CONSULT 103

2 Introduction As shown in the first part of the report, the need, apparent in all market segments, to satisfy the desire for personalization of the cars, as well as for a feeling of driving in the open air, were a strong leitmotif of the Frankfurt Motor Show One of the main contributions to this multifunctional need is certainly the transparent roof, which has nearly reached industrial production in the different niches, while the sunroof has reached mass production in all segments of car production, even the most popular. This second part of the report will try to describe the result of codesign among designers, car and sunroof manufacturers and glassmakers. Transparent roofs The whole roof, conceived also as a sunroof, Fig. 2a & b Glass to glass joints on the Smart City Fig. 2b Fig. 1 Monolithic roof of the Mercedes SL320 might be realized in several ways, as seen in those exhibited at the Frankfurt Motor Show Fixed With this solution, the roof is composed of one monolithic pane of glass, as in the new SL320 (see Figure 1) by Mercedes. It is like a pavillon which wraps the windscreen and rear window in different ways, though the best example is the detailed glass to glass joints at the front and back in the SL320. Other examples of these kinds of joints are on the Smart City car at the front (see Figure 2a) and back (see Figure 2b). In three parts In this case the back of the roof is fixed, the front tilts as a wind panel, while the middle panel is movable, underlying the fixed back panel when open. This is already the classic solution for the Porsche Targa, where the three parts are closed. The glass to glass joints are shown in Figure 3. Pavillon This type of roof is composed of several moving lamella panels and can be considered the most advanced solution at present. It is a very innovative concept for glassmakers, on a level with the opaque lamellae solution in the Mercedes Class A. The best example of this solution is that of the five louvered glass panels on the MC2 concept car by Ford. The idea of a 104

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5 Fig. 3a Fig. 3b low noise and draught levels despite large opening; ventilator setting which can also be used in poor weather; no rattling or vibration with the roof open; security against break-in at least as good as existing sunroofs made of steel (as in the Class A) or glass (as in the MC2); electrical operation. When the roof is opened (see Figure 4b), the deflector props up first, followed by the other lamellae, which slide out parallel to the roof skin, moving along the same lines as the folding roof one after the other right to the rear (see Figure 4c). In the ventilator setting, the deflector is fully open, while the fifth lamella is Fig. 4a Fig. 3c Fig. 3a, b & c Three-part roof of the Porsche Targa Fig. 4a, b & c Opening opaque roof of the Mercedes Class A Fig. 4b roof made up of lamellae is based on the Multivent prototype, developed by Webasto as a new roof system for the Mercedes Class A (see Figure 4a) in five opaque twin-shell steel lamellae. The system seems to satisfy the following points: greatly enhanced ratio of roof area to roof opening; Fig. 4c 107

6 Fig. 5 Fig. 6 only slightly ajar. Figure 5, showing the internal frame, gives an indication of the assembly production of the flushing roof. In order to understand the real evolution of the lamella concept, it is interesting to note the previous design of the roof, with a single, flexible, opaque fabric, used for example in the Ford Fiesta (see Figure 6), or in many cabriolet cars. In two parts An example of a two-part transparent roof is the Technas SUV by Mitsubishi. This kind of roof is composed of a glass wind deflector which can prop up, together with the Fig. 7 Fig. 5 Internal frame of the Class A Fig. 6 Opaque roof of the Ford Fiesta with folding fabric fixed or moving large part. The fixed part can be in glass, as in a particular Smart model, which has a wind deflector, a fixed glass panel in the middle and a fixed rear panel also in glass. Among other two-part roofs we can also mention the Megane Scenic (designed by Inalfa), with the wind flap in Venus glass and the second part (see Figure 7) in a flexible opaque fabric. Two examples, both by Webasto, and which belong to the category of sunroof equipment, are the three glass panels on the Peugeot 806 and the two twin moving glass panels in the Megane family by Renault. Sunroofs The variety of sunroofs, fixed-tilting, in one, two or three parts, with or without shading device and electrically sliding underneath, was one of the leitmotifs of the Frankfurt Motor Show This result can be taken as the first spin-off of the increasing interest of designers in the last five years. Flushing encapsulation The flushing encapsulation achieved with PU-RIM technology now gives full integration between the sunroof and the body roof. The best examples shown at Frankfurt 1997 were: the Opel Corsa Advantage (see Figure 8); the recent VW Passat; Fig. 8 Fig. 7 The Megane Scenic by Renault Fig. 8 The Opel Corsa Advantage with flushing sunroof 108

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8 Fig. 9 Fig. 10 the new VW Golf with OM flushing sunroof; the Mercedes Coupé Sport and E55 AMG Avant-garde. Two examples, the sunroof on the Mercedes E320 and on the Nissan Micra (see Figure 9), illustrate the difference between the flushing encapsulated sunroof mentioned above and previous, non-flushing encapsulated panels. Rockwell and Webasto also seem to have produced flushing encapsulated technology. Moving devices Competition on the moving device on sunroofs seems to be between sliding systems composed of either one or two parts, as in the Mercedes S500 (see Figure 10), or in the Mercedes Pullman (see Figure 11). In evolution with the sliding device, there are two new concepts of a tilting or winding up system. The latter has already been developed by Webasto, as well as a new concept (see Figure 12), designed by students of the Art Center College of Design in Pasadena, USA, an overall winner in a competition organized by Webasto for ideas on sunroof designs for MPV and SUV vehicles. The concept of a tilting sunroof was presented by Inalfa. Another interesting tilting device for large sunroofs has been produced by the VW Karman Ghia designer in a MPV Opel View II vehicle. Solar control and privacy glasses As seen in the first part of this report, there is increasing interest among car and sunroof Fig. 9 The Nissan Micra - an example of non-flushing sunroofs Fig. 10 Sunroof of the Mercedes S500 Fig. 11 Sunroof of the Mercedes Pullman Fig. 12 A new concept for tilting sunroofs Fig. 11 Fig

9 makers in using more solar control or privacy glasses in the sunroof. Evidence of this is Saint-Gobain s new Venus privacy glass, the moving part of the transparent roof on the Porsche Targa, shown at the Webasto stand, and the Inalfa sunroofs on the F1000, Farmont F1000 Plus and F1000 Compact, as well as the Volvo C70 (see Figure 13). Increased transparent surface The increased transparent surface is well represented by the Land Rover Freelander. The Station Wagon has one sunroof and the XE Hardback model has two transparent glass panels in the front area (see Figure 14). Photo-voltaic sunroofs Rockwell and Webasto have presented a Fig. 14 Fig. 13 The Inalfa sunroof on the Volvo C70 feasible industrial solution for a photo-voltaic sunroof which decreases the internal air temperature of a car in full sun by nearly 25 C. Mirrors Fig. 13 No real innovation seems to have been developed at present in this area, except for the AISIN deflector, with retractable rear-under mirrors. However, electrochromatic (EC) fluid anti-glare technology by Gentex has been consolidated, with a small increase of internal EC mirrors. In addition, there was a significant growth of aspherical mirrors, not only in Germany, but also in France and Japan. This is in line with the increase of all round visibility, for which other approaches were also noted. No mention was made either of microcamera or prismatic technologies. However, interestingly, a marked trend was noted among designers to situate the external mirror in a more convenient position, in order to reduce the dead angle both in width and height without the use of aspherical mirrors. Anti-glare EC internal mirrors are still confined to the upper class level of cars, while the only external EC mirror mentioned is by BMW (see Figure 15). As well as reducing glare, the BMW external mirror is equipped with an Fig. 14 The Landrover XE Hardback sunroof with two panels Fig. 15 External EC mirrors exhibited by BMW Fig

10 automatic dip function, which lowers the reflecting surface as soon as the driver shifts to reverse, providing a good view of the curb when backing into a parking space, for instance. Aspherical mirrors Aspherical mirrors seem to be increasing their penetration in all parts of the world. In fact, Frankfurt 1997 showed many cars in which aspherical mirrors have been adopted for final production. In previous reports, great interest was noticed especially among German car makers. Now, however, aspherical mirrors are part of the equipment for car makers in France and Japan, even in mass produced cars. Citroen s choice for the mass produced car Xsara can be considered the typical aspherical mirror in France, while in Japan it is Mitsubishi s choice in the mass produced Carisma car. Mercedes has also adopted the aspherical mirror in the Smart City car (see Figure 16), demonstrating its necessity in all car segments. However, car makers also commented on the present limitations of aspherical mirrors. One of these is the distortion of the reflecting image in the curved part of the mirror. They also give an incorrect perception of the rear distance of approaching cars, especially ones appearing in the dead lateral zone. Aspherical mirrors also need to be larger than normal mirrors. In fact on Fig. 16 Aspherical mirror of the Smart City car by Mercedes Fig. 17 Image distortion in the Smart City s aspherical mirror the Carisma car, the increase of the dead angle of an aspherical mirror - without increasing the size of the mirror - is quite small, only 5.3. In most cases, when the aspherical mirror is enlarged to the necessary size it does not integrate well, especially on the small cars (see Figures 16 and 17), or even on middle size cars. Innovative concepts The only really innovative concept, which is perhaps a sign that the micro-camera is not yet ready for mass production, is the AISIN prototype Rear deflector with folding mirror. The rear mirror is placed on the back bumper and operates by an electrical mechanism which retracts and opens the deflector. When the deflector is opened, the mirror view is quite large both in height and breadth. When the deflector is closed, the rear shape of the car looks aerodynamically simple and pleasing to the eye. Designers trends for mirror positions The main trends were for increasing the rear visibility of mirrors and achieving better integration of external mirror supports. Hence the external mirror is joined with the external body, rather than the lateral window. This is in order to improve lateral and lower rear vision, as well as to better integrate the mirror support with the body shape and colour. Typical examples are the solution on the concept car 112

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12 Audi Al 2 (see Figure 18) and the BMW car. Even the innovative Unicar, designed by IKA, and the Technas, by Mitsubishi, show an integrated solution for the external mirror. Internal mirrors have also begun to be conceived as more integrated with the internal body, using joints, as opposed to the present solution of glue on the inside of the glass windscreen. A very representative example is the Smart City car, where the well designed support for the internal mirror is attached to the inside of the car roof. The mirror producers Metagal (Brazil) and Ficosa (Spain) showed they are ready to satisfy the latest trends of designers. Mirror producers stands The presence of mirror producers was scattered among the stands of assemblers such as Marelli (AISIN) and a number of others. However, a larger number of mirror producers had their own stands at Frankfurt 1997 compared to the previous edition of the show. The most noticeable stands of verticalized rear mirror manufacturers were those of Metagal Fig. 18 External mirror on the Audi Al 2 concept car Fig. 19 Fig. 20 and Ficosa. Metagal can be considered one of the most international verticalized mirror manufacturing companies, for its wide range of mirrors (see Figure 19), as well as the very special shape, size, integrated plastic support, electrical and electronic devices. Ficosa also showed a wide range of car mirrors, as well as the most recent advancement in aspherical reflecting surfaces (see Figure 20) and a fairly complex and integrated plastic support. Antiglare mirrors were presented at Metagal s stand but not at Ficosa s. The latter intends to penetrate the South American and Far Eastern (China and Malaysia) markets much more intensively. Navigation display systems As mentioned in the first part of this report, the trend for greater colour variety of the trim and dashboard has certainly made it necessary to reduce internal reflection in the glazing of interior surfaces, especially for the monitor of the navigation system map. Navigation systems Fig. 19 Metagal mirrors with sophisticated plastic support Fig. 20 Automotive mirror products by Ficosa 114

13 are now being mass produced for a wide range of cars. The ergonomic concept of the suitable position for the map display is changing from the lateral position, beside the driver, to the front, just over the steering wheel area or on the windscreen, as an HUD using different technologies, such as a hologram or selective reflection. Frankfurt 1997 did not show any HUDs on the windscreen. However, it did show a more ergonomic and safer position of the map display in front of the steering wheel area, where it is almost integrated onto the dashboard. An example of this is the new massproduced Golf (VW) and the Trail Runner sports car by Nissan (see Figure 21). However, in my opinion, the challenge for the glassmaker is undoubtedly to find a solution for the mass production of HUD on the windscreen, as announced by Mitsubishi for the Technas model and by Nissan for the Trail Runner model. Another important feature related to navigation systems, which is already in production in some cases, is the glass aerial. There is a preference to insert this in the rear window, with implications for aesthetics and for multi-point terminal technology. An important example is a future solution by Ford for a rear window with five aerials, presented at the Ford stand at Frankfurt Other technology is also being developed for Mercedes cars. It includes, for instance, the Dynamic APS, for the transfer of traffic information, the Tele AID, for linking to emergency call centres and the Linguatronic Fig. 21 HUD in the Nissan Trail Runner Fig. 22 Drop shape lenses of the Mercedes Class A telephonic voice operation system. The main detailed presentations of navigation systems at the show were: the AISIN display or voice system, adopted mainly by Toyota (AISIN produced about 160,000 navigation display systems in 1996); the Delco system, adopted mainly by BMW; the Blaupunkt (Bosch) system, adopted mainly by Mercedes; the Alpine system, adopted mainly by GM, Chrysler, Volvo, Renault and Fiat; the Nippondenso system, adopted mainly by Toyota and Honda; the Marelli system, adopted mainly by Fiat, Alfa, Lancia and Peugeot; the Siemens system, operating mainly with GM and Ford. Plastic lenses The evolution of transparent plastic on headlight lenses shows two essential trends. On one hand, there has been a sharp increase of plastic lenses in nearly all innovative cars where the concept of complex shape involves greater integration of the lenses with the front body of the car. This has led to three main shapes of plastic lenses: the drop shape, as in the innovative Class A Mercedes (see Figure 22) and the Toyota Funcar; 115

14 adapted to the new high-tech concept of lighting is the Audi Al2, where a single light source (see Figure 24) positioned at one side projects a ray of light through a system of preliminary lenses and high guides to four head lenses. The new design is shorter and lighter and illuminates the road surface more effectively. The rear lights are also designed to illuminate the area surrounding the vehicle reliably, with improved all round visibility during night driving. The new lighting technology could also have consequences for glazing. The evolution of transparent plastic lenses should always be considered a precursor of what could happen if transparent plastic should replace glazing in the automotive field. the round shape, first brought in at Frankfurt 1995 by Mercedes and now applied in several high-level and sports cars such as the Porsche 911 Turbo (see Figure 23) and now the 911 Carrera, where the single round lens is split into three integrated lenses which blend very well with the front body; the rectangular shape, typified by the lenses in Ford cars, now more integrated with the front body by one very thin lens and a second lens in the lower front. On the other hand, the second trend is for versatility with the new lighting technology. Important innovations in this field are modifying the shape and integration of plastic headlight lenses, which have proved to be more versatile than glass. One example of lenses Fig. 23 Round plastic lenses of the Porsche 911 Turbo *Consultant MG Consult - Italy Information Service n. 13 See coupon on the last page Fig. 24 The new concept of lighting in the Audi Al 2 116