TYPES OF CHASSIS FRAMES:
There are three types of chassis frames and they are listed below. The Automobile chassis frame is exposed to both bending and torsional distortion during vehicle travel over typical ground surfaces. The various chassis-member cross-section forms that find use under certain running conditions include.
1. Conventional frame
2. Integral frame
3. Semi-integral frame
1. Conventional frame:
It has two long side members and 5 to 6 cross members joined together with the help of rivets and bolts. The frame sections are used generally.
a. Channel Section – Good resistance to bending
b. Tubular Section – Good resistance to Torsion
c. Box Section – Good resistance to both bending and Torsion
2. Integral Frame:
This frame is used now a days in most of the cars. There is no frame and all the assembly units are attached to the body. All the functions of the frame carried out by the body itself. Due to elimination of long frame it is cheaper and due to less weight most economical also. Only disadvantage is repairing is difficult.
3. Semi – Integral Frame:
In some vehicles half frame is fixed in the front end on which engine gear box and front suspension is mounted. It has the advantage when the vehicle is met with accident the front frame can be taken easily to replace the damaged chassis frame. This type of frame is used in some of the European and American cars.
What exactly is a frame? | Types of Chassis Frames
The frame is the most important aspect of the chassis, on which the other components are placed. The frame should be highly stable and solid in order to withstand the shocks, bends, stresses, and vibrations that the vehicle experiences when on the road.
The wheels and tyre arrangements are supported by the frame. The front of the frame is small to allow for a small turning circle for the front wheels. It widens out at the back to have more cabin space.
Side Members and Cross Member Construction | Types of Chassis Frames
The frame side-members that cross the wheelbase between the front and rear axles must be capable of supporting the full amount of sprung weight. The weight of the portion of the vehicle covered by the suspension structure is referred to as the sprung weight. These members’ binding stiffness must be able to withstand their inherent inclination to drag. The use of open-channel pressed sections or thin-walled hollow round or rectangular sections may provide the maximum bending stiffness of the frame members compared to their weight.
A 4 mm C-section channel with a channel web-depth ratio of around 3:1 is generally used as side chassis member. This gives a 15-fold bending resistance to the same cross-sectional area than the solid square section.
Two C-section channels may be mounted to establish a rigid load-supporting member for heavy-duty applications. The side members could have a dual-section channel to provide additional strength and support to the existing chassis across a highly loaded place.
What exactly are Sub-Frames? | Types of Chassis Frames
A motor vehicle’s various parts are bolted directly to the frame’s mainframe members or cross members. However, the engine and gearbox are often mounted on a simple sub-frame. The mainframe normally supports the sub-frame at three points. The aim of this design is to protect such modules from the mainframe’s twisting and bending.
Types of chassis frames according to the engine’s mounting position:
• Engine mount in front
• Engine mount in front yet crosswise
• Engine mount in the middle of the chassis
• Engine mount in the back of the chassis
Front-mounted engine / Engine mounted in front:
Traditionally, engines are mounted in the front and drive is delivered to the wheels from the back. The following are some of the benefits of this type: There is enough room for luggage behind the back seat; the weight of the cars is evenly distributed; the cooling system is more efficient;
The engine is mounted in the front, but it is installed crosswise:
There is a low-floor option. The vehicle has a greater potential for road carrying capacity. Clutch, gearbox, and differential are normally built as a single unit to save money.
The engine is mounted in the middle of the chassis:
As in Leyland royal tiger worldmaster buses simply known as Leyland Worldmaster historically piled by, drive is provided to the rear. This structure provides maximum floor space for use.
The engine is mounted in the rear of the vehicle.
This drive uses a real engine, and the cars that use it are called dolphins. The benefits include: A flat floor is possible due to the absence of long propeller shafts; The centre of gravity is reduced, resulting in stable driving; Better adhesion on the ground, especially while climbing hills.
The drawbacks are as follows: When climbing hills, adequate adhesion can be compromised because the vehicle’s weight shifts to the rear, decreasing the weight on the front wheel; Since the transmission, clutch, gearbox, and differential are all grouped together, repairing and adjusting them becomes complicated.