Chassis frame is a part of automobile body structure, which is the backbone of the structure and the basis of all parts of vehicle body structure, it plays a very important role in automobile body structure
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?
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.
Difference between Chassis and Frames
Chassis: A vehicle’s chassis is the bare minimal design that allows it to move, such as a frame that is equipped with an engine, tyres, axles, steering, and brakes, among other things. The skeleton structure of a vehicle that has been equipped with the majority of its mechanical components.
Frame: The frame of a vehicle serves as the vehicle’s body, with all other pieces linked to it (either with bolts, rivets, or welds) by means of the frame. The chassis is fastened to the frame via bolts.
Side Members and Cross Member Construction 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 a side chassis member. This gives a 15-fold bending resistance to the same cross-sectional area as 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?
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 load-carrying capacity. The 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 World Master buses, simply known as Leyland Worldmaster historically piled by, the 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.
What do you mean by Auto Chassis?
How many types of car chassis are there?
1. Conventional frame
2. Integral frame
3. Semi-integral frame
What does the frame of a car do?
The traditional method of making vehicles began with a frame, which was a type of ladder-looking structure consisting of steel rails and crosspieces. After that, everything was fastened to that foundation. Axles, engine, and drive train are all examples of mechanical components. Then there’s the body. This kind of construction is still often used for heavier vehicles.
Nowadays, the majority of passenger automobiles are constructed using the body as a structural component. Axles, engine, and drive train are generally bolted directly to the body instead of being welded. It reduces the amount of material used, the weight of the assembly, and the amount of time required.
What are sub frames in automobiles?
How important is the frame in an automobile?
How is a car frame made?
Afterwards, in the 1970s, the Uni-body was developed, which was essentially a box for each axle affixed to the proper end of the cabin compartment between the fenders, with the intermediate structure being reinforced bodywork. Nowadays, automobiles are composed of both frame and body components.
Which factors are to be considered for car frame design?
1. Composite Monocoque or Tubular space frame design for the chassis.
2. Material Considerations for the Chassis – While aluminium is not as robust as steel, it is much lighter. Its rigidity is about one-third that of steel; nevertheless, it is approximately one-third the weight of steel. Steel, the most often used material for tubular space frames, keeps its strength and ductility even after being welded together.
3. There are five fundamental load cases resulting from typical operating circumstances. Bending loading – Torsion loading – Combination of bending and torsional loading – Lateral Loading– Loading from the front and rear
4. Inertia loading of the structure adds to overall loading; Inertial loading is always larger than static loading; longitudinal loading is formed when the vehicle accelerates and decelerates. These inertial loading and longitudinal loading are the parts of dynamic loading.
5. If the car traverses an uneven road, t he front and rear axles are subjected to a moment referred to as Lateral loading.
6. Asymmetric loading occurs when one wheel impacts a raised obstacle or falls into a pit while the other wheel does not.
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