Automotive Suspension - Coursework Example

Automotive Suspension Section A) Review the function of your selected component and describe how it operates within the system of which it is a part Function The automotive suspension is a system in the automobiles design that is used to make a connection of the vehicle parts to its wheel system and in isolation and management of vibrations as well as vibrations (Asthana, Jain & Titi, 2002). Generally, the suspension system serves to ensure that the automobile maneuver on the surface is facilitated through an efficient control design that takes care of the terrain or road nature. In such an aspect, the automobile suspension system enables the body of the automobile to be protected against various movement positions that can damage its condition. In light of such protection needs, springs as well as shock absorbers are incorporated to the system in order to reduce the impact that the rest of automobile makes on various road conditions. The braking system is also part of the larger suspension system since it enables the control of the vehicle through the wheel control. Automotive suspension spring or the leaf spring is one of the suspension system components. Carriage or a leaf spring has been considered being one of the simplest springs that are often used to offer suspension and linkages in vehicles. In addition, a leaf spring is known to be the ancient springing model that reminds one of the ancient medieval designs in the automobile industry. Most of these systems have the got similar basic components and usually operate in a similar manner. Their differences are usually experienced in the arrangement method of their basic components. Generally, the spring is the core of nearly all suspension system. Operation The component absorbs shock forces while maintaining correct riding height. If the spring is worn out or damaged, other suspension elements shift out of their proper positions and are subject to increased wear. The increased effect of shock impairs the vehicle’s handling. However, various types of springs are used in the suspension systems. These in clued the following coil, torsion bar, leaf inclusive of both mono and multi-leaf types, and finally air springs. Generally, automotive suspension springs are classified by the amount of deflection exhibited under a specific load. This is usually referred to as the spring rate. In relation to the physics law, a force (weight) applied to a spring causes it to compress in direct proportion to the force applied. Whenever that force is removed, the spring regains its original position if not overloaded (Erjavec and Knowles, 2003). It is imperative to note that, a heavy vehicle requires stiffer springs than a lightweight car. Automotive springs usually take care of two fundamental vertical actions: jounce and rebounce. Jounce occurs when a wheel of a vehicle hits a bump and moves up. When this action is experienced, the suspension system acts to pull in the top of the wheel, maintaining an equal distance between the two front wheels and preventing a sideways scrubbing action as the wheel moves up and down. Rebounce occurs when the wheel hits a dip or hole and moves downward. For this case, the suspension system acts to move the wheel in at both the top and bottom equally, while maintaining an equal distance between the wheels. Section B) Describe both the operational requirements and in-service conditions for your component and relate them to the material properties required Operational Requirements Operational requirements of an efficient suspension system must cater for the various systems linkage with a special focus on the shock isolation and elimination of excessive carriage vibrations. The suspension system cannot be considered in isolation without making consideration of related systems such as the contact system given by the wheels. The integrity of the suspension system must consider the other systems in order to facilitate a compatible suspension material. Various operational requirements must be met for the suspension system to be operational, which must take care of the carriage and shock alleviation needs. To incorporate the suspension system to the core of the automobile integrity, these system requirements are connected with focus on the ability of the automobile to deal with different stability issues. In light of the convergence of various automobile system needs at the suspension point, there are various operational requirements that come into the front line. The tire is perhaps one of the most important parts of the suspension system due to its interaction with impact that the suspension system is intended to solve. Contact point between the tire and the rest of the automobile becomes an integral requirement for the overall suspension design. This is the first stage of the suspension system, which is enhanced by ensuring that the pneumatic tires are compressed and flexed to facilitate a solid contact with the rest of the suspension system (Asthana 2002, p293). The other important requirement in the suspension system is the wheel system, which connects the wheels by way of an axle. Besides connecting the wheels in a system that creates a control system particularly in steering, the connectivity on to the carriage is important in determining how efficient the suspension system is designed. Various components of the wheel system enable the suspension system to operate in alleviation of shock. Shock and vibration that can damage or are undesirable for the carriage and the body should be arrested at the suspension contact. These components include the shock absorbers and connecting systems that link the wheel system with the body. In-Service Conditions Wear and tear value exerted by the weight must be considered when choosing the choice of material and the design. The material for the leaf spring should be hard and therefore wear resistant. It should also be resistant to corrosion and natural weathering. The material chosen for the suspension system must support the weight of the carriage in various respects. In this respect, the young modulus and Poisson’s ratio must be considered in choosing the material. This means that the material should be strong and therefore having a high modulus of elasticity. Springs and shock dampers are usually applied in several suspension systems. Considerations to be made for an operational system must therefore comprise of all tire and wheel factors such as pressure and spring strength. Carriage weight may dictate the specific type of material and suspension material design. Section C): From a consideration of the required material properties outlined in part a), justify a material for your selected component based on maximizing functionality and minimizing weight and cost. Relevant performance indices should be used to justify material selection. Maximizing Functionality Functional value of the suspension system of choice must address the various issues of the automotive design with respect to arresting shock and vibration needs. The leaf spring for instance made from strong material such as high quality steel is capable of handling various flexibility issues. Suspension flexibility must be exact as dictated by the demands of the weight and road conditions (Srinivasan, 2003). The automobile in question will be supported by various suspension requirements that the automobile has, which must be catered for by the suspension system. Weight from the automobile’s body is usually required to be known in advance and the effective shock that creates impact on the suspension system is targeted for material choice and design purposes. In light of the needs that the weight and shock exerted on the body, the type of suspension design applied is guided by the needs that the entire automobile system has. The design of the leaf spring is such that the number of the leaves applied can be changed for purposes of fitting with the specific functional requirements. The material of choice for making spring leaves considering its function is high quality steel, more specifically high carbon steel. Minimizing Weight and Cost In order to minimize the weight that the leaf spring incorporates in to the automobile system, thin leaves or metal bars are applied instead of a single piece of metal. By such a design, the weight of the entire system is not only reduced by the effective cost is considerably reduced. Consequently, the spring goes back and forth from jounce to rebound. In most cases, jounce and rebounce become smaller and smaller. This is caused by friction of the spring’s molecular structure and the suspension pivot joints. A shock absorber is then added to each suspension to dampen and stop the motion of the spring after jounce. However, all of the vehicle’s weight supported by the suspension system is known as sprung weight (Erjavec, 2001). The weight of those components not supported by the springs is known as unsprung weight. The vehicle’s body, frame, engine, transmission, and all of its components are considered sprung weight. Under-car pars classified as unsprung weight include the steering knuckles and rear axle assemblies. It is good to note that, in general, the lower the ratio of unsprung weight to sprung weight, the better the vehicle’s ride will be. It therefore follows that the functionality elements and concerns that include weight and cost with regard to steel application in the manufacture of leaf spring for suspension systems. Section D) Assuming that your selected component is required in a large batch quantity (10,000), justify and explain a manufacturing route. Manufacturing Route In the manufacturing process for the leaf spring, there are various stages that can be identified for the complete design and production. The process can be traced from the production of the separate spring leaves made from high carbon steel. In light of the processing required on the various metal bars to constitute applicable spring leaves, they are first processed separately in preparation for the leaf spring assembling. Firstly, the metal bars are flattened in line with specific width needs by cold rolling the metal bars (Rajput, 2007). Since the spring leaves are joined at certain lengths for achieving of spring properties, it is important that they are then marked out for punching at the specific central points for adjoining purposes. The marked areas are then punched using a specific technique that befits the adjoining technique in order for the leaf spring to achieve its standards. The spring leaves are then heat treated to ensure that they serve the role of the part that each of the leaves plays in the composite structure. Heating is done and various treatments such as end tapering, end punching or eye forming are carried out on the separate leaves made from the previously flattened bars. In most cases, the metal is Blue-Tempered or Annealed. Alternatively, there are specialized treatments carried on each of the leaves depending on the role that each leaf plays, such as cambering, quenching and nibbing. In addition, the various metal leaves are polished in various surface enhancement techniques such as stress peening as well as painting (Erjavec, 2001). After making the various markings for the various enhancement processes such as eye boring and bush insertion, the eye processing is finished up allowing the final stage to take place. Final processing involves correction for various defects, presetting the final design and allowing specification testing followed by the actual assemblage of the individual leaves. Paint may be redone in areas where it may slough off during final touches to ensure that the product remains in a good condition. Packaging for marketing is then done with specific branding and load specification clearly being indicated. Justification It is important that each of the applied metal leaves is done separately to ensure that they all pass the quality aspect in achieving integrity for the suspension system. Assembling the separate parts after passing the quality standards ensures that the product will also be of high quality. The large quantity of 10,000 pieces may be enhanced by identifying the number of different pieces needed, rolling out a division of labour system and a comprehensive assemblage system to cater for the details. Automation of the system may however prove to be a more time and cost efficient option. Section E) Explain how your selected manufacturing route influences the microstructure of the material and the consequent affect on properties. Influence on Microstructure Manufacturing routes applied in the production of the leaf sprig involve fabrication of metal pieces to achieve the final product (Srinivasan, 2001). Intense heating on the metallic material during shaping needs does not significantly alter the quality of the product to withstand its shock and vibration forces from the automotive system. When the metal bars are annealed, the microstructure of the metal is refined such that its machinability is improved. Annealing is also done before cold working to soften the material in readiness for the succeeding process. . In most cases, the metal is tempered to give it the toughness required while alleviating brittleness of the high carbon steel. Tempering however leads to loss of yield strength even as it helps in relieving the stresses in the cold worked and previously annealed material. Various treatment processes in the production route enhance properties of the final product in different ways. Tapering end treatment and other end treatments for the various metal leaves applied in the product ensure that the product faces various adjoining challenges as well as meeting safety needs for use of the product. Punching and boring specific types of holes at specified locations enable the assembling of the leaves into the final product. Without such fastening techniques, the final product would be difficult to design with such features. Shaping of the final product in light with the pressure exerted by the body determines the efficiency of the suspension system. Other stages such as paining serve both protection purposes against rust and adding an appealing aesthetic touch to the product. References Asthana, K., Jain, B., & Titi K. (2002) Automobile engineering, New Delhi, India: Tata McGraw Hill Education Erjavec, J. & Knowles , D. (2003) Classroom manual for automotive suspension and steering systems, 3rd edn. Clifton Park, NY: Delmar Learning Erjavec, J. (2001) Automotive technology: a systems approach. Stamford, CT: Thomsom Learning Rajput, R. K. (2007) A textbook of automobile engineering, New Delhi, India: Laxmi Publications Srinivasan, S. (2001) Automobile engines, New Delhi, India: Tata McGraw Hill Education Srinivasan, S. (2003) Automobile mechanics, New Delhi, India: Tata McGraw Hill Education Read More