The automobile horn system is an essential part that produces sound for safety reasons. Production of horn system is classified based on two main processes. One of them is the caulking process which makes body assembly and forms the lower part of the horn system. The control dimension of body assembly is a crucial factor for quality control as the sound of the horn is largely determined by the control dimension. In this paper it has been found that plastic deformation of body and its restoration after caulking process is the main reason for the change in control dimension. Typically, 100 specimens of the body assembly were employed and the results were compared (Restore the Length of the Body) with another data set that had the same body but different parts in the assembly. Monte carlo simulation was used for tolerance analysis of control dimension for the body assembly including the deformation of the body in the caulking process. The simulation was identified as a good model to predict the satisfaction ratio of the control dimension with high accuracy and was observed to be useful in designing parts of the assembly and equipment used in the caulking process.

Snow removal equipment in Korea has been developed to remove snow from roads by pushing it away with snow shovels or dispersing it into the air with snow blowers. However, in urban areas, it is difficult to use snow blowers. And piled snow on sidewalks not only hinder pedestrians from walking by, but also melt onto the roads during the day and freeze at night, causing traffic accidents. As a solution to this, there has been a need to develop a machine which melts snow on the place where high priority is given for snow clearing such as airports, roads of frequent black ice occurrence, and main traffic facilities. This paper describes the main design points and experimental results in developing the snow melting system composed of the burner, blower, water tank, etc. Hot air from the burner spouts into the water tank and some of it rises through the outer jacket where hot air is mixed with water in the tank, heating it. Hot air spouted to the bottom of water tank and hot water pouring from the head of the outer jacket are two sources of snow melting in designing the equipment.

Quality of manufactured goods under mass production system depends largely upon accuracy rate of quality control. Tolerance analysis is a useful method to set up a guide for inspection of product. However it usually would happen that strict tolerance provoke very high manufacturing cost. It is the main concern of tolerance analysis to find optimal values of tolerance to satisfy both quality and cost. This paper presents three tolerance analysis methods and its corresponding results upon automobile steering system to analysis the merits and demerits of each method.

Every mechanical part for mass production has dimensions with tolerances in engineering drawing. Tolerance is given to guarantee assemble parts together satisfying functional requirements and dimensional constraints. Tolerance is essential factor for standardization of parts or assembly and has huge influence on manufacturing cost. It will be desirable to have tolerances as broad as possible for minimizing manufacturing cost. This paper describes tolerance analysis of u-joint assembly that is a part of automobile steering system. Within the range of tolerances of parts, accumulated effect is estimated by arithmetic calculation, probability theory and Monte carlo simulation. Each result is compared to investigate the method for increasing productivity.