Generally, a car body has three pillars, namely, front pillar (A pillar), middle pillar (B pillar) and rear pillar (C pillar) from front to back. For an automobile, the column not only plays a supporting role, but also plays the role of a door frame. In front of the column is a connecting column connecting the left and right front roof and the front cabin. The front pillar is between the engine compartment and the cockpit, above the left and right rearview mirrors, which will block part of your turning vision, especially the left turn, so there are many discussions.
When designers consider the geometric scheme of the front column, they must also consider the angle at which the front column blocks the driver's sight. Under normal circumstances, when the driver passes through the front column line of sight, the binocular overlap angle is 5 ~ 6 degrees. From the driver's comfort, the smaller the overlap angle, the better. However, this involves the rigidity of the front column. It is a contradiction to have a certain geometric size to maintain the high rigidity of the front column and to reduce the influence of the driver's line of sight occlusion. Designers must strive to balance the two to achieve the best results.
At the North American International Auto Show 200 1, Sweden Volvo introduced the latest concept car SCC, which changed the front column into a transparent form and embedded transparent glass, so that drivers can observe the outside world through the column and minimize the blind area of vision. The center pillar not only supports the roof, but also supports the front and rear doors. Some accessories, such as seat belts in front seats, are installed on the center pillar, which sometimes wears wires and harnesses. Therefore, most central columns have convex radius to ensure good force transmission performance.
The cross-sectional shape of the center pillar of modern automobile is complex, which is welded by several stamped steel plates. With the development of automobile manufacturing technology, the closed cross-section center pillar has appeared without welding. Its rigidity is greatly improved and its weight is greatly reduced, which is beneficial to the lightweight of modern cars. However, some designers simply canceled the center pillar from the convenience of passengers getting on and off.
The most typical car is French Citroen C3 car. The center pillar on the left and right sides of the car body is cancelled, and the front and rear doors are opposite, so passengers can get on and off completely without obstacles. Of course, if the center pillar is abolished, the front and rear pillars should be strengthened accordingly, and the body structure should have a new form and the material selection is different.