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A.: It seems to me that now almost all the vehicles are frameless.
B.: I cannot agree with you. In 1920, every motor vehicle besides a few cars
based on motorcycles had a frame. Since then, nearly all cars have shifted
to a unitary construction but nearly all trucks and buses still use frames.
A.: Then maybe, you’ll remind me how frame rails are designed.
B.: Sure. There are three main designs for frame rails: C-shaped, boxed, and
hat.
A.: If I am not mistaken, the most common is the C-shaped frame rail which
is made by taking a flat piece of steel and rolling both sides over to form
a C-shaped beam running the length of the vehicle.
B.: You are right. And a boxed frame rail is made by bending a piece of steel
into four sides and then welding where both ends meet. So the construc-
tion resembles a box.
A.: And I have no idea what a hat frame rail is. What does it resemble?
B.: A hat frame rail resembles a “U” and may be either right-side-up or in-
verted with the open area facing down.
A.: Is it commonly used?
B.: You see, they were not commonly used due to weakness, however they
could be found on 1936—1954 Chevrolet cars and some Studebakers. For-
gotten for a while, the hat frame rail gained popularity again when compa-
nies started welding it to the bottom of unitary construction.
A.: Thanks a lot for your comments. I’d like to continue our discussion a little
bit later.
B.: You are welcome.
Достарыңызбен бөлісу: 
