Developing an Assembly Method to Fix the Glass to the Body with High Precision

Another difficult problem was figuring out how to fix the glass to the pillars. In particular, there was an extremely minute gap between the glass on the body side and door side outside the pillar, and the roof panel, and even a slight misalignment in the position of the glass would make it difficult to open the doors. To make matters worse, the manufacturing process resulted in a +/-1 mm error in external dimensions. In order to ensure a smooth outer surface and smooth opening and closing of doors, we had to allow for the error in the external dimensions of the glass while also coming up with a precise method for fixing the glass to the body.

The conventional method involved securing the glass to the body, and then covering the surrounding area with rubber strips. This method would require the use of wide strips of rubber in order to allow for the dimensional error in the glass. Since we had put so much effort into the design of the SVX, we were not willing to use this method.

A new method was proposed, using encapsulated strips. This method involved setting the glass into a mold and then injecting a urethane resin around the glass, in order to integrate it with the glass. As long as the glass was positioned accurately in the mold, this method allowed the problems of dimensional error and appearance to be overcome. In addition to finishing the glass with extremely high precision, quality was also dramatically improved.

A variety of other efforts were made to improve precision, including the technology for fixing the windshield and rear window to the body. One such improvement was the use of guide pins to determine positioning. The alignment of pins installed in windows with holes created in the roof allowed precise positioning. However, this precision positioning affected the precision in the body manufacturing.

In order to monitor the pinholes in the body, a method was devised to install television cameras. With this system, images from cameras monitoring the positions of holes were processed by computer, so that the robots performed welding only when the holes were in the correct positions. If the holes were misaligned, the work was stopped so that the parts would not continue on to other lines.

Shigeo Nomura, project manager of the Body Design Department, said,

“The SVX is a completely new model that overcomes design challenges unprecedented in various fields. Our team succeeded in part due to strong support from developers at cooperating manufacturers. In particular, the round canopy was achieved through the efforts of our team working closely together with glass manufacturers and rubber manufacturers.”

Devising Pillar Structure and Shape to Ensure Body Rigidity 

While the problem with glass was resolved, there were still many problems in achieving a round canopy. One of these problems was how to structure pillars, doors, and glass. When it became possible to manufacture glass with large curvatures, it also became possible to combine it with conventional pillar structures. However, this resulted in unevenness between the pillar and glass, which was unacceptable both visually and aerodynamically. If we were not able to reduce the projections from glass junction surfaces as much as possible to produce a flush glass-to-glass surface, we would not be able to say that we had achieved our goal of producing a round canopy. 

In order to not expose the pillar to the outer surface of the cabin, in other words to achieve a completely hidden pillar, we first had to make the pillar as thin as possible. However, reducing the strength of the pillar would reduce the rigidity of the entire body, adversely affecting handling stability and a variety of other areas. 

The staff made a dummy model, with daringly thin pillars, based on the Alcyone. This started from a desire to check how much thin pillars would affect strength and rigidity. The results of the first test were extremely disappointing. Even if the bottom of the body was reinforced, the required rigidity could not be obtained unless the pillars had sufficient strength to support the cross-sectional area. 

And this was the start of considerable trouble and effort. In addition to reviewing the thickness of the steel plate, we also considered what type of pillar structure and shape would be advantageous for strength, and repeated a variety of prototyping and testing. If the pillars were thickened in order to provide strength, they became visible through the glass, which was undesirable visually. This might have also obstructed the driver’s view. The development staff worked together with the staff of the Design Department to perform in-depth checks of pillar shape. 

After repeating a variety of studies, they found a size and shape that did not obstruct the driver’s view and also provided the required cross-sectional area. In addition, one of the flanges required to shape the front/rear ends of a pillar by spot welding was no longer needed because arc welding was now used. The development of this new technology resulted in increased strength and ensured the required cross-sectional area. 

As a result, the final design was slightly thicker than the idea model. However, all conditions were satisfied and we were able to achieve strength that surpassed our goal. 

To be continued next week….

In the Attic named Pleiades
“THE PHILOSOPHY OF GRAND TOURER”

The most characteristic part of the SVX was the round canopy made of glass-to-glass construction. In order to achieve this canopy, extremely advanced technological innovations were required. However, if this canopy had been designed simply for the sake of its design, we probably would not have spent so much time and effort on it. The fresh driving experience surrounded by this canopy, excellent visibility, and aerodynamic performance were backed by functional support, and were the reason we decided to develop it. 

For the car itself, although enjoyment is an important element, the underlying point is the pursuit of functionality. I believe that is the way forward for Subaru. 

We are sincere in our enjoyment of “driving”. Although I’ve listed it as the final of these three points, it would not be strange to list it as the first. The fundamental appeal of a car is to “drive”, and driving is what I enjoy doing more than anything else. 

The same is true in its driving quality. The SVX has been given the characteristics of a grand tourer. It is comfortable even when driving long distances, and yet provides enjoyment of driving comparable to a sports car. If I were told I could pick only one car, this is what it would be. 

“Safety”, “functionality”, and “driving”. When written this way, it seems like nothing more than common sense. However, these words represent the blood and soul of Subaru engineering. I could find no greater joy than if you “feel Subaru soul” in the Alcyone SVX. 

Extract from THE PHILOSOPHY OF GRAND TOURER”

When the Alcyone SVX was developed as a “4WD grand touring sports car”, the catchphrase used to first introduce it to the public was “500 miles a day”. Subaru’s enthusiasm to achieve a new-generation grand tourer was reflected in this catchphrase. This week we reprint the prefatory note of Nobumasa Saeki, the general manager of the Subaru engineering division at that time, from the booklet “THE PHILOSOPHY OF GRAND TOURER”. 

Our goals

Alcyone SVX. This car is the new symbol of Subaru. We made the SVX from our hearts. It is the kind of car that we wanted to drive. It was the kind of car we wanted. It was what we wanted a car to be. As engineers, as drivers, we built this car based on our own true feelings. That is why both technologically and emotionally, it is appropriate to call the SVX the symbol of Subaru. 

For the development of this car, those of us at Subaru had an unwritten law to represent our unique values. This can be referred to as technological policy, or the philosophy of Subaru. In summary, this can be squeezed into three points; our starting point was to fulfill each of these, and they were also our final goal in the process of making the car. So, these three basic points should be examined at the start of this book. 

First, we wanted to build “safety”. Although it goes without saying at this point, a car cannot be enjoyed without advanced safety features. In particular, the concept of “active safety to prevent accidents” is so deeply ingrained in each individual engineer that it could be called a Subaru tradition. 

As you know, Subaru was the first manufacturer in Japan to implement FF and 4WD, and these were technological challenges based on the concept of active safety. During the development of the SVX, for which we wanted to obtain handling comparable to a sports car, we thoroughly felt the appeal of driving FR. However, not even one of us considered selecting FR. This is because, when thinking about standards for active safety, obviously 4WD takes precedence over FR. Everyone wants to drive the safest car possible.

We were particular about “functionality”. In the same way as “safety”, our functional realism comes from Subaru’s backbone in the tradition of the manufacture of aircraft. This is based on the concept that technology that is backed by superior functionality has true meaning. 

Recently, we often speak of a “new function principle” and “sure engineering”. Advanced technology is apt to be a technology for the sake of technology. The “new function principle” is a pledge to not fall into the trap of technology supremacy. “New” refers to a strong sense of purpose to “pursue sure technology that serves people”. It also plays the role of strictly checking trends in technology. 

Extract from THE PHILOSOPHY OF GRAND TOURER

Alcyone

The Alcyone, designed as the “world’s first two-plus-two 4WD specialty”, featured innovative ideas such as L-shaped spoke steering and airplane-type door handles. In “Cartopia Vol. 156” (June 1985), four engineers involved in development discussed the concept, exterior, interior, and aerodynamic performance in the “Talking about Alcyone” column. Here we reprint their comments about the concept and aerodynamic performance.

Alcyone, featuring creativity and international appeal, is Subaru’s leading model.

Mitsuo Takahashi (Manager of the Engineering Division, Subaru at that time)
Photo published in magazine

Subaru pioneered the FF method, as well as 4WD in a passenger vehicle, and continues to do new things that other manufacturers are not doing. We were aware that we had high creativity, and the purpose of this vehicle was to use such creativity to appeal to the general public, and it was a start point for this vehicle.

The goal was to design a creative specialty car as Subaru’s leading model with international appeal and suitable for the era of high-speed 4WD passenger vehicles, infused with everything that Subaru has to offer. Simply put, we set out to make the “symbol of Subaru” that you would want most as your own car.

Development of the Alcyone proceeded at the same time as the Leone series. The Leone four-door sedan is Subaru’s flagship model, and must not have a very outlandish design. It must appeal to a broad range of customers. On the other hand, for a touring wagon we felt a bit more adventurous and wanted to try something a bit more imposing. So, with the Alcyone we decided to try something new. Actually, the All New Leone was based on the Alcyone. Much of what was developed for the Alcyone was used in the All New Leone. Therefore, with this we were finally able to come up with a scenario.

Even though we were trying many new things, there were three cornerstones.

The first was aerodynamics. Aerodynamic characteristics are an advanced technology for automobiles. We think we were entering the era to compete over the efficiency rather than pure horsepower build-up. Increasing efficiency while increasing performance. Reduce noise while improving performance. Improve riding comfort while improving maneuverability. In this way, although in the past we had to choose between the two, now we must have both. We decided to do our best to see what we could achieve in aerodynamics, and specifically we wanted to get a CD value of less than 0.30.

The second was the two-plus-two concept. There are some four-passenger cars in the world that are categorized as specialty cars. We decided to design such a car while focusing on the front seats to provide comfort. As a result, it would have a better look and better aerodynamics. This would achieve comfortable driving at high speed. Comfortable even at full speed. Although there are speed limits in the United States and Japan, this comfort at very high speeds can be experienced in Europe. A car that is designed to be driven with confidence at high speeds over 200 km/h will be extremely comfortable at 100 km/h. Also, the Alcyone is comfortable at low speeds because it was improved starting with the low speed range and as a result we attained comfortable high speed performance from low speed to full throttle.

The third was finding how far we could take high-speed driving in 4WD. Our idea was to make the most of 4WD, and 4WD is extremely rare in this class of car. Maybe only Audi, but that is a redesigned coupe, not a drastically new design like this. So, we were aiming to create a new genre of car with high-speed 4WD.

Others can better explain the details in each area, but as soon as we had completed a 1/5 model the enthusiasm had spread throughout the entire company. For example, we have tried many times to see how far we can reduce the hood surface to make the most of aerodynamic characteristics of flat-four engines, until we were unable to go any further. However, let’s try it again. We showed them the 1/5 model and said, “Look, this is what we are making. Don’t you want to help?” And they said, “Give us a week.” Then they came back with some ideas. So, in a way the 1/5 model was the motivation that led us and sped up the project.

Extract from Cartopia Vol.156

In November 1993, 300 units of a special limited edition SVX S40 were sold to commemorate the 40th anniversary of the founding of FHI. This limited edition model was based on version E, with blue glass for the windows and an instrument panel with an enhanced monotone especially for the S40. The seats featured Jacquard fabric, and the limited edition body color, peacock blue metal, was used on the roof and trunk lid as well.

This was followed in July 1994 with the release of 300 units of a limited edition S40II with redesigned interior and exterior. The interior featured a specially designed instrument panel and misty Moquette seats. The same body color was used for the roof and trunk lid, in either light silver metallic or emerald green mica. In addition, 500 units of a limited edition SVX S3 were released in December of the same year, featuring 16-inch BBS aluminum wheels and a new “SVX Super Real Sound System”. Body colors included light silver as well as blue mica and bright green mica.

The SVX S4 released in July 1995 featured four-sensor four-channel ABS, rear viscous LSD, and dual SRS airbags (driver and passenger seats) as standard, as well as a mesh-type front grille, wood grain instrument panel, and Ecsaine seats and trim. Available body colors included Bordeaux red mica, bright green mica, and light silver metallic.

SVX　S40

S40II

SVX S3

SVX S4

From October 26th to November 6th in 1989, the 28th Tokyo Motor Show was held as the formal opening event for at the Japan Convention Center (Makuhari Messe), an exhibition hall in Makuhari, Chiba Prefecture, which was larger in scale than the previous venue in Harumi, Tokyo. Subaru presented an exhibition that focused on “driving” with the theme “Creating a New Driving Experience:  Subaru The Excellence”. The “SVX” concept car exhibited on the main stage was a “grand sporty specialty” developed with the goal of providing a new dimension in the joy of driving. The power unit featured a 3.3L four cam 24-valve horizontally opposed six cylinder engine. This concept model was full of dreams and the latest technology of the time, including VTD (variable torque distribution system) to maximize the driving force of 4WD, electric rear steering that actively steered the rear wheels for ideal steering stability, and four-sensor four-channel controlled four-wheel anti-lock braking. 

This concept model was released, with very few changes in styling, as the “Alcyone SVX” on September 18th, 1991. The development concept was a “grand tourer that achieves an abundant personal life for adults”. Aiming to embody the three points of “driving pleasure”, “driving satisfaction”, and “proud ownership”, this model featured a 3.3L horizontally opposed six cylinder engine, a newly developed VTD 4WD system, a four-wheel steering system (4WS), and a “glass to glass” round canopy reminiscent of a jet fighter canopy. 

There were two grades available: Version E and Version L (with CD auto-changer (12 CDs), leather seats, 4WS, four-sensor four-channel ABS, cruise control, and automatic headlights). 

The 3.3L horizontally opposed six cylinder engine featured a redesigned valve system from four-cylinder DOHC engines. Direct type DOHC combines high output with low fuel consumption and low noise, and has continued to expand into four-cylinder DOHC engines. 

To improve handling in 4WD VTD (variable torque distribution) systems that were front heavy due to the use of six cylinders, the front and rear torque distribution for the center differential was variable from the initial 36: 64 to direct four-wheel drive. First introduced in the SVX, this became an indispensable system for future high-output cars from Subaru. 

The Alcyone, released in Japan in June 1985, featured an OHC/EGI 1.8L horizontally opposed four cylinder turbo engine. Variations included “VS Turbo” with front-wheel drive and 5-speed manual transmission, and “VR Turbo” with 4WD and either 5-speed manual transmission or 3-speed automatic transmission. The name Alcyone comes from the name of the brightest star in the Pleiades star cluster.

In February 1986, an automatic transmission model was added to the “VS Turbo”, and the “VR Turbo Sunroof”, 4WD model with a sunroof, was added (February 27th). In November 1985, the “Subaru ACX-II”, a four-wheel drive concept model based on the Alcyone, was exhibited at the 26th Tokyo Motor Show. This model featured a 2.7L horizontally opposed six cylinder engine, and a center differential full-time 4WD.

This concept model was released in July 1987 as “VX”. This model featured the most advanced technology of the time, including a 2.7L flat-six engine with an “EGI” electronically controlled fuel injection system, a four-wheel drive system equipped with an “ACT-4” electronically controlled active torque split 4WD, an “ABS” four-wheel anti-lock braking system, electronically controlled motor driven hydraulic power steering, an all-range electronically controlled 4-speed automatic “E-4AT”, and an “EP-S” electronically controlled air suspension system. The 4WD and 5-speed manual transmission “VR” featured a center differential full-time 4WD with a bevel gear. The automatic transmission variations of both the “VR” and “VS” featured E-4AT, while the automatic transmission variation of only the “VR” featured ACT-4. In February 1989, the body colors were renewed, but no further changes were made to the line up.

“Subaru ACX-II”

Alcyone VX 4WD

Size: Length 4,510 mm x Width 1,690 mm x Height 1,335 mm
Wheelbase: 2,465 mm
Tread: (Front) 1,435 mm  (Rear) 1,440 mm
Min. ground clearance: 165 mm
Vehicle weight: 1,300 kg
Riding capacity: Four persons

Engine: ER27
Model: Horizontally opposed six cylinder water cooled OHC
Displacement: 2,672 cc
Max. output: 150 PS / 5,200 rpm.
Max. torque: 21.5kg” m / 4,000 rpm.

Suspension
Front: Strut independent suspension
Rear: Semi-trailing arm-type independent suspension