Windshield

Here we consider the evolution of frontal glass in general-purpose cars. It should be noted that it was slower on trucks, and in the 1970s, many models of open-air sports cars used a simple glass shield instead of the windshield, which barely covers the driver.

Early Period

The first cars had an open body and, like open horse-drawn carriages, did not need glazing. However, the growth of speeds quickly forced the designers to think about protecting the driver and passengers from the oncoming air flow. In addition, carriage-type closed bodies began to appear in which the windshield was a necessary detail.

The very first version of the windshield was a round transparent shield, fixed in front of the driver on the steering column. The protection given to them was close to symbolic, nevertheless its presence has already made it possible to make driving more comfortable and safe.

Already at the beginning of the 20th century, many models had a windshield made from the same material as the usual window. Later, it was made of tempered glass, which significantly increased safety. However, tempered glass shatters into fragments even with a not very strong impact, so this technology was suitable for windshield only with reservations.

On open bodies, the windshield was folded completely or out of two halves, and on closed ones it was usually suspended on the upper hinges and could be folded out to improve the ventilation of the cabin (therefore, the wiper axes were located on top of the glass). So the windshield was until the mid 1930s, the changes affected only the shape of the glass; besides, they began to make it only solid, without division into two halves and air vents. In the 1920s, there are wipers with an electric, mechanical (manual or motor shaft) or pneumatic (vacuum from the engine intake manifold) drive.

Some models of open cars (they were commonly called "dual-cowl phaeton", they had two separate passenger compartments) had two windshields, separately for the front and rear passenger compartments. Probably the last car of this type was the Chrysler Imperial Parade Phaeton , produced in the USA in 1952 to participate in various official events.

Back in the 1920s, "safe" windshields of the " triplex " type appeared - from two layers of glass and a layer of film laid between them; for example, on the Ford A and its licensed version of the GAZ-A, the windshield was three-layered. The first such glass was installed on a 1919 Ford T model. Such a glass upon impact did not break into pieces, as usual, and did not crumble into small fragments, as hardened, and crack, remaining on the film. The film of the first three-layer glass quickly turned yellow, but in an accident (which were not rare in the motorized America of those years), this windshield was much safer.

V-shaped glasses

Already by the mid-1930s, the development of automotive design triggered an important change in the design of frontal glass. As a result of the popularization of the work of a number of researchers, for example, the German Edmund Rumpler and Hungarian Paul Yaraya ^[1] , in the area of ​​air flow around a car, the shape of the body becomes more rounded, better meeting the aerodynamic requirements. In such conditions, a solid flat windshield, installed vertically or almost vertically, did not suit the designers.

However, the technology of mass production of curved glass in those years did not exist. The output was V-shaped windshields of two flat halves that fit well into the rounded contours of the car bodies of the second half of the 1930s. The separation of the glass into two parts connected with a sealer at a certain angle to each other forced the two wipers to be installed, since one could not clean both halves of the V-shaped glass (although the wiper on the passenger’s side was for some time available extra money).

One of the first examples of the use of such a solution was the Chrysler Airflow model, created as a result of continuing research in the direction given by the earlier works of P. Yaray ^[2] . It is curious that the body of this car by modern researchers is classified as a “false stream”, since the real decrease in air resistance did not exceed 25%. ^[2]

V-shaped glass was placed at an angle to the vertical (initially it was small and was about 20-35 °), which allowed not only to improve the external perception of the car, to make it more visually dynamic, but also to improve the streamlined body in practice.

For security reasons, there is a gradual abandonment of folding and folding glass, popular in the previous era - to the detriment of the cabin ventilation, which was now carried out through a system of side windows that appeared in the glazing of the side doors. The windshield on all types of bodies begin to install inside a powerful opening with a rubber seal. With a strong blow to the head of the driver or passenger on such a glass, it completely flew out of the opening, quenching the impact energy. Machines with a windshield fixed in the opening can often be distinguished by the lower location of the wiper axles, - previously they had to be placed on top of them so that they were folded down with the glass.

These constructive innovations became generally accepted during the second half of the 1930s - 1940s. The only exceptions were some open cars, for example, the military Willys MB (1941) had a folding windshield in a light frame.

For these years, the first attempts have been made to improve the driver’s view by creating a panoramic glass, while at the same time improving the streamlining of the car, and to a greater extent giving it a more streamlined appearance.

Since the production technology of curved glasses of this size was still absent, the windshield was assembled from several smaller planar sizes separated by racks ^[3] ( on the illustration. On the left ).

After the war, the shape of the car body began to change rapidly, however, the glass still remained V-shaped. At the turn of the 1940s and 50s, there was a revision of the proportions of passenger car bodies, the height of the sides of the body decreased, and the glazing area increased, thereby also increasing the area of ​​the windshield ^[4] ( on the ill. Right ).

Curved windshields

The increased demands on the optical quality of the windshield for a long time did not allow it to be bent, although the rear windows were made curved long before that; for example, the Victory, which was mastered in production in 1946, had a curved rear window. In this case, its use was not very successful - the glass was small in size, moreover, the defect in the production was not uncommon ^[5] , and because of the imperfect production technology, the glass did not have the necessary optical properties - the direct rails through it looked strongly curved . ^{[6] The} rear window of the ZIM (1949) was also curved ^[7] , and by that time technological problems were solved, and the size of the glass was significantly increased compared to Victory. The windshield on these cars remained V-shaped from two flat halves ^[7] .

The first curved windshield on a production car appeared in 1934 on the most expensive versions of the Chrysler Airflow model line, however, it didn’t get any spread. On mass models, curved windshields began to appear only in the early 1950s. Of course, they are better than the V-shaped, fit into the smooth rounded contours of cars of these years. Meanwhile, from a practical point of view, they had quite a few flaws - they were worse cleaned with a wiper, they were harder and more expensive to manufacture, they were blinding in the sun. In addition, the technology of manufacturing curved glass of the "triplex" type did not exist for some time, and after its appearance they were expensive, so the original curved glass was forced to be simple reddened, although the technology of manufacturing flat "triplexes" was well mastered in the prewar period. In the US, curved "triplexes" have learned to do in the fifties, but in Europe, as well as in the USSR, their widespread use begins only in the seventies.

Initially, curved windshields were made of two halves, like old V-shaped. On cars Cadillac such windshields appeared in the 1948 model year. Somewhat later, curved windshields appeared on the cars of other American manufacturers (on the Buick in 1949, on the Chevrolet in 1950, on the Dodge and Plymouth in 1951, Fordy in 1952, and one-piece etc.). Bend start to make and rear window. Manual, vacuum or electric actuated washers begin to appear, first as an option.

Later curved windshields spread around the world. The first curved windshields in the USSR were installed on the Moskvich-402 and Volga GAZ-21 (1956).

The windshield area, as well as the glazing in general, continuously increased over the next decade, both due to the increase in its height and bend, and due to a greater inclination, which made it possible to significantly improve visibility and, consequently, the active safety of the car. The increased area of ​​glazing has led to the fact that the car's interior has become more noticeable to an external observer - this has led designers to the need for more careful study of its style, bringing it in line with the body. In particular, in the 1950s, salons became popular, according to the color of the trim corresponding to the body, or, on the contrary, forming a specially selected pleasant contrast combination with it. To this were added the latest developments in the field of plastics - plastics, leatherette, Lurex fabrics, and so on.

Panoramic windshields

Panoramic windshields were the height of the 1950s technology development in the field of car glass manufacturing. The Cadillac again became a pioneer here - in 1953 a panoramic windshield appeared on the Eldorado model, the corners of which were bent on the sidewalls of the body, and the uprights were vertical. In those years, it seemed very unusual, and technologies that allow making such glasses were just developed. However, in 1954, all Cadillacs already had such a windshield. And in 1955 they were joined by most American manufacturers. Rear windows also begin to make panoramic, at first - from three parts.

The peak of the development of “panoramas” was the 1958 and 1959 model years. During this period, windshields appeared with “piled up” rear pillars with a backward inclination, variously curved pillars, etc. Mercury offered cars with a windshield that has a bend in the upper part, coming onto the roof and supposedly allowing you to see traffic lights better. in the town. In the same years, tinted windows and windshields with a darkened upper part became widespread in the USA; even the so-called athermal glass appeared , that is, not letting the heat into the car and not letting it heat up from the sun (true, their prevalence in those years was low).

The most extreme version of glazing on the production car in those years was, perhaps, the “Cadillacs” and “Buicky” of the 1959 model year in the body of the “four-door hardtop”: they had not only a huge panoramic windshield with a reverse inclination of the uprights, but also a very wide panoramic rear of the so-called “Vista” type, besides - a completely flat roof panel resting on very light racks. Appearance was excellent, however, such a roof structure was dangerous when overturning a car, and a year later it was discontinued.

The American concept cars of those years had even larger panoramic windshields, for example, on the project of the atomic car Ford Nucleon, the entire panoramic windshield had to go far to the sidewall. Other concept cars even included the replacement of a glass-enclosed cabin with a fully glazed airplane-type lantern, or even two separate lanterns (for the right and left halves of the cabin), but in practice this did not happen.

In Europe, however, they reacted to the new product with more restraint - all the more so because the technical level of Europe lagged behind that of North America, and many cars in those years still had V-shaped glass installed (including the domestic GAZ-M- Victory). 20 and ZIMe ), and even solid flat (" Moskvich-400 ", still produced the old models Fiat and Renault, Lloyd 600 / Alexander, and many others). On more modern cars, such as the Volga , BMW 501 or Mercedes-Benz Ponton, already curved front and rear windows were installed, but most manufacturers did not even think about introducing panoramas according to the American model. European firms that are closely associated with the American auto industry - Facel-Vega , Opel and Vauxhall - tried in the late fifties to bring to the market models with panoramic glazing of the “American type”, but on a European-sized car - much more compact than most American ones - this design solution led to a sharp decrease in the size of doorways and difficult landing in the salon, which caused quite fair criticism. More practical Europeans have opted for the convenience of entry and exit, rather than bright design. As a result, panoramic windows in Europe were used infrequently, and as a rule, in the least extravagant version - minimally setting on the sidewall and with traditionally hemmed back racks. These were the windshields and on the domestic "Seagull" and ZIL-111. The majority of European car manufacturers relatively short era of the heyday of panoramic windows just “slipped”.

By the end of the 1950s, it turned out that the vertical - and, especially, reverse-tilting - windscreen pillar (in the United States, such a pillar was called the dog leg for the characteristic bend) prevents entry and exit from the car, weakens the body and causes excessive deformation in an accident. ^[4] The panoramic glass itself is also not without flaws - it glares strongly, distorts the picture. Finally, the very development of American design at the very beginning of the 1960s led to the appearance of cars with more square, “chopped” contours, the exterior of which panoramic windows did not fit well. As a result, the latest novelty of the 1961-62 model years in the United States was a simple, almost flat windshield. A few years existed half-panorama glass, which had small bends in the lower part and a curved stand of the opening, but by the middle of the decade they also completely disappeared.

Thus, even in the USA, the history of panoramic glasses actually boiled down to a relatively short period - from 1953 to 1961, and they were generally widespread only from 1955 to 1959 ... 1960. And only the company "Chrysler" produced several models of the highest class ( Imperial ) with half-panoramic windshields until the mid-sixties.

Nowadays, however, there is a partial return to the idea of ​​a panoramic windshield, but now this term means not very curved glass, setting on the sidewall of the body, but only the presence of relatively small additional windows in the front roof pillars, separated from the front windshield. This style appeared on minivans (for example, Renault Espace ), and is now often used on small cars with relatively high bodies, like the Toyota Auris . Some of the distribution, mainly - on the French models, also have windshields, partially calling on the roof of the car. About the return of these "panoramas" in the foreseeable future, speech is no longer coming due to the radical tightening of requirements for car safety in a collision.

Further history

By the mid-1960s, panoramic windows were almost forgotten. Rare outdated models, developed in the previous era, were supplied with them for some more time, but the majority of cars received windshields, curved only to fit into the angular design of cars of this era. In the following decades, no special innovations occurred. Windshields every year tilt back more and more to improve aerodynamics; accordingly, their area and labor intensity of production grows.

In the 1980s - 1990s, due to the advent of new technologies, the design of the windshield and its opening changes: rubber seals disappear, the glass is now glued directly into the opening, this reduces the aerodynamic resistance and increases the rigidity of the body and the development of a technology of applying a special coating on its edges to hold it firmly in the opening with glue.

There are new coatings that reduce the pollution of glass. Некоторое распространение получает встроенный в лобовое стекло обогрев . Технология получения трёхслойных стёкол продолжает совершенствоваться, они становятся всё безопаснее. Массовое распространение получают атермальные стёкла, не пропускающие в салон тепло солнечного света. Стеклоочистители и стеклоомыватели получают автоматическое включение от датчика дождя.

Любопытная разработка — система отображения на лобовом стекле данных о скорости движения и иной информации. Другая новинка — прибор ночного видения для езды в темноте, проецирующий картинку прямо на лобовое стекло.

В настоящее время лобовое стекло современного автомобиля — изготовленное с прецизионной точностью, технически сложное, наукоёмкое изделие, продукт занявшей десятилетия эволюции.

Как показали опыты американского исследователя В. Э. Лэя ^[4] на моделях в аэродинамической трубе, геометрия и расположение лобового стекла серьёзно влияют на аэродинамику автомобиля.

Минимальные значения коэффициента обтекаемости Сх (то есть, наименьшее аэродинамическе сопротивление) при прочих равных получаются, когда угол наклона ветрового стекла составляет 45…50 градусов к вертикали, дальнейшее увеличение наклона к серьёзному улучшению обтекаемости не ведёт. Разница между наилучшим и наихудшим (при вертикальном лобовом стекле) значениями составила 8…13 %.

Те же опыты показывают, что разница в коэффициентах обтекаемости автомобиля с плоским лобовым стеклом и с лобовым стеклом наиболее выгодной с точки зрения аэродинамики формой (полукруглого сечения, недостижимого на реальном автомобиле) при прочих равных составляет 7…12 %.

Кроме того, в литературе ^[4] указано, что немалую роль в формировании аэродинамической картины кузова легкового автомобиля играет оформление переходов от лобового стекла к крыше, боковинам кузова и капоту, которые должны быть максимально плавными. Сегодня широко используется спойлер-отсекатель в виде «вздёрнутой» задней кромки капота, отводящий поток воздуха от границы капота и ветрового стекла, благодаря чему стеклоочистители оказываются в аэродинамической «тени». Водосточные желобки недопустимо располагать в местах перехода от лобового стекла к боковинам кузова и крыше, так как на этих переходах резко возрастает скорость потока воздуха. ^[4] Отмечается важность использования современных вклееных стёкол, которые не только снижают ощутимо сопротивление воздуха, но и повышают структурную прочность кузова в целом.

В британском английском ( Великобритания , Австралия , Новая Зеландия ) для обозначения лобового стекла используется термин «windscreen» . Кроме того, лобовое стекло — щиток старинных открытых спортивных автомобилей высотой ниже 20 см (точнее, 8 дюймов) иногда обозначается как «aeroscreen» . ^[eight]

В американском английском используется термин «windshield» , а «windscreen» обычно означает ворсистую или полиуретановую накладку на микрофон, уменьшающую фоновые шумы. В британском английском всё с точностью наоборот.

В японском английском аналогичным термином для обозначения лобового стекла является «front window» .

На немецком «лобовое стекло» будет «Windschutzscheibe» , а на французском — «pare-brise» . В итальянском и испанском используются похожие и лингвистически родственные термины «parabrezza» и «parabrisas» соответственно.