what is it in a car and what is its purpose?
Reading articles about cars, including on our website, readers come across many incomprehensible words. One of them is a spar.
What is it?
Definition
As we already wrote on Vodi.su, there are three main types of body structure:
- frame;
- frameless or load-bearing body;
- integrated frame.
Spars are used in any of them. In the frame structure, they are often called longitudinal beams - they stretch along the entire length of the body, and at the engine mounting points and at the rear they are made especially strong and rigid, since the greatest load is concentrated here.
In frameless cars, they are used in a subframe that sits under the hood and reinforces the front of the car where the engine is located. The same can be said about the integrated body. Also, with their help, mudguards, the floor of the passenger compartment and the trunk are reinforced.
The word itself, as can be seen from its pronunciation, does not belong to the original Slavic vocabulary, but comes from the French verb - Longer, which means to go along, to follow. That is, it stretches along the length of the body.
A similar design is used in aviation, machine tool manufacturing, shipbuilding and so on. Respectively, spar - this is the main load-bearing beam of the body, to which all other frame parts are attached.
The spars can have different shapes, but in cross section they resemble the letter P, that is, it is an ordinary channel, or they are made in the form of a hollow pipe with a rectangular section. Thanks to this, they can easily withstand the weight of the engine, gearbox, passenger compartment, without deforming. This shape provides them with strength - try, for example, bending a sheet of cardboard and a matchbox - the latter will be much harder to bend.
Design features and purpose
If you drive a frame-type SUV, then the spars stretch along the entire body. They can be welded together or connected with rivets and powerful bolts. Looking through the catalog of spare parts for your car, you can see the names: spar left, right, rear.
In the front, they are screwed to the crossbar. If we are talking about a load-bearing or integrated body, then a subframe can be welded to them, or all of them together form one structure.
The main tasks assigned to the spars:
- body reinforcement;
- additional depreciation;
- impact cushioning in the event of a collision.
In addition, thanks to them, the geometry is preserved. If an experienced driver buys a used car, then first of all he inspects not the interior and the condition of the upholstery, but the bottom, since it accounts for the entire weight of the car.
When inspecting the car, the spars can only be clearly seen from below.
Spars related problems
If the geometry of the body is broken, the car has been in an accident, or the bottom had to be digested due to corrosion, then the side members may crack or move. It should be said that their repair is very expensive even on a car with a frame body structure. If the body is a load-bearing or integrated frame, then they have to be digested, and it is almost impossible to do it qualitatively - the weld cannot provide the same level of rigidity as solid metal.
Pay attention to one more thing - if the body, especially the bottom, was repaired by welding, then their properties are completely violated.
It is not recommended to buy such a car, because when driving at high speed, the consequences can be disastrous:
- deterioration of depreciation characteristics;
- displacement or cracks of spars;
- deterioration in ride comfort.
Moreover, the dynamic characteristics of the car itself also change, it becomes more difficult to drive it.
If you cannot do without a replacement, then order it only from professionals who have equipment for arc welding. You can find these parts for sale, although they are quite expensive. Install spars of the same size and material as the old ones.
On a car with a load-bearing body, bent spars can be straightened at the stand - caroliner. A car drives onto it, specialists measure the angles of deflection of the load-bearing structural elements, and, thanks to hydraulic rods, align them to the desired level.
Loading…
