Frame SUV - what is it? Device and principle of operation. Photo and video

As we wrote earlier on our website Vodi.su, the main differences between an SUV and a crossover are the presence of all-wheel drive, a transfer case with a reduction gear, an inter-axle or inter-axle differential that can be switched off, and a real SUV has a carrier frame.

Hence the question arises, which will be considered in this article - what is a frame and a frame SUV?

Car frame - device and purpose

To date, the most common are the following types of body structures:

• frame;
• with load-bearing body;
• with integrated frame.

The difference between them is significant.

1. In the first case, the frame is the skeleton of the car and all other components are attached to it: the suspension, the body itself, all the units.
2. In the second case, the cabin acts as a frame and all components and assemblies are attached to it. Cars with an integrated frame differ from frame cars in that the frame is tightly integrated with the body, that is, this is such a compromise between the two previous types.

There are several types of car frame:

• spars - the frame consists of spars - connected by welding, bolts or rivets - and cross members between the spars;
• spinal - the base of the frame is a transmission pipe, to which everything else is already attached;
• fork-spinal - forks from spars are attached to the transmission pipe for installation of power units on them;
• load-bearing base - the frame is combined with the floor of the car, resulting in a load-bearing platform on which the cab, units, suspension are mounted.

To reduce the weight of sports cars, tubular or lattice frames welded from lightweight pipes are used. This frame resembles a lattice, which is why it got its name.

Each of these types of frames is divided into a large number of subspecies, almost any manufacturer is trying to bring something of their own to the design.

For example, spar frames are X-shaped, transverse, ladder, X-shaped transverse, and so on. It is also worth noting that most SUVs are built on the basis of spar frames.

The frame is the heaviest part of any vehicle, accounting for approximately 15-20 percent by weight. That is why frame SUVs can weigh up to three and a half tons, or even more, while the trend today is that manufacturers are trying to minimize the overall weight of the car.

A number of requirements are put forward to the frame of modern cars, including SUVs:

• strength - it must withstand various bending, torsion loads;
• rigidity - during operation, it ensures the invariable position of all nodes attached to it;
• lightness - the level of fuel consumption, as well as the cost of producing a car, depends on this parameter;
• maintainability;
• manufacturability - ease of production and maintenance.

Thus, the main purpose of the SUV frame:

• take on and distribute the load;
• maintain the same arrangement of units, body elements, alignment of axles and universal joints;
• transfer of forces from the steering mechanism, brake system, axles to the total mass of the vehicle.

Pros and cons of frame construction

The first cars had a frame structure. A lot of things have changed since those times, but, as we can see, the engineers did not abandon the supporting frame.

What are its advantages?

First of all, it is quite simple to manufacture, it is much easier for engineers to calculate the structure and design of the frame, as well as its characteristics. Whereas the creation of cars with a monocoque body requires the use of more complex calculation methods.

The second important quality is the comfort of the passengers themselves. This is achieved by elastic joints and rubber dampers, such as reinforced rubber pads. Frame SUVs have better sound insulation and vibration isolation, since all the loads from the suspension are transferred to the frame and damped by the shock absorption system.

Thirdly, the frame greatly expands the possibilities for tuning and changing the shape of the car. It can be easily lengthened or shortened, for this it is enough to install shorter spars, or vice versa, add cross members (if you have the appropriate tools and skills). In addition, different cabs and body types can be installed on the same frame.

Frame cars are less prone to corrosion (surprisingly, this is true). The whole reason is that there are fewer hidden planes, and the frame itself is better ventilated.

It is easier to treat with anti-corrosion agents. Well, do not forget that the frame is assembled from a more durable metal, and the cross members and spars are thicker.

There are, of course, a number of disadvantages:

• a significant increase in mass with all the ensuing consequences - more fuel is consumed, a more powerful engine is required, lower speed;
• spars "eat up" part of the usable space, respectively, a less comfortable interior, hence the significant size of frame SUVs;
• the frame is inferior to the load-bearing body in terms of torsional rigidity - you probably noticed that it is easier to twist, for example, a sheet of rough cardboard than a cardboard box;
• worse passive safety due to the possibility of the cabin breaking off the mounts and further deformations.

The most popular frame SUVs

It is clear that there is nothing ideal and everyone decides for himself what to sacrifice when buying a particular car. However, frame SUVs still roam our roads.

Domestic - all off-road UAZ models: UAZ 469, UAZ Hunter, UAZ Patriot, UAZ 3160. Indeed, UAZ vehicles will be able to drive everywhere. True, if you recall the first models, they did not differ in comfort. More modern ones may well compete with the best examples of foreign SUVs, but, unfortunately, they do not differ in economy.

Comparison of some models in terms of stability in frontal impacts. (scale from 1 to 10)

Toyota - in an article about Japanese crossovers and SUVs on Vodi.su, we listed all the frame SUVs of this company: Land Cruisers, Tundra, Sequoia, Hilux are all frame SUVs.

The most expensive SUVs with a frame include the G, GL, GLA and GLK classes from Mercedes. In principle, they are all called - SUVs, which means "Off-road".

M-class cars are also built on the basis of a frame structure.

Land Rover Defender, Jeep Wrangler, Volkswagen Amarok, BMW X1-X6, Opel Antara and Frontera, Dodge RAM, Ford Expedition. Even quite affordable Chinese cars from Great Wall, or Korean SsangYong are also frame SUVs.

Video about Great Wall models.

Comparison of the best: Land Cruiser 200 vs. Nissan Patrol.

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