In this study, we examined the assembly and components of a 40-feet container chassis based on its 3D shape. Utilizing the finite element method, we conducted structural analysis considering the total weight, including the 40-ton weight specified in automotive regulations, along with a safety margin of 1.5 under extreme load conditions. And also fixed and junction conditions were applied to the chassis system. Subsequently, we presented the maximum stress results derived from the structural analysis of both the overall chassis system and its individual components. Finally, we evaluated the structural stability of the 40-feet container chassis by comparing and reviewing the maximum stress with the yield strength of the material used for each component.
In this study, in order to review the structural stability of a Sub-frame assembly mounted on a 5-ton dump truck with a telescopic cylinder type that can secure price competitiveness through cost reduction effect and an extended loading box that satisfies automobile safety standards, the 3D shape design technique for a main component parts is presented. In addition, structural analysis based on the finite element method is performed with the load condition applied to a safety factor 3.0 and boundary condition assigned to the lower part of the Sub-frame. By comparing and examining the maximum stress result from the structural analysis of the entire Sub-frame assembly and individual component and a yield strength of each material applied to each component, a design technique that can assure the structural stability of the Sub-frame assembly is presented.
In order to develop a 1 ton truck rear wheel air suspension module, this study designed and manufactured a Z-type spring and air suspension module test jig to optimize the design and reliability of the Z-type spring and vibration-free air suspension module, which are core parts, and to secure the reliability of the developed parts. We were able to achieve the technology development goal of this thesis by making a prototype and conducting a test evaluation at an external test and research institute to perform the vibration endurance test aimed in this study.
This study aims to respond to the market of Tata Daewoo commercial vehicles in emerging countries (Southeast Asia) lightweight and cost-saving type for the production of dump trucks with secured price competitiveness requested to develop a square deck, and accordingly. This study is a 15-ton dump modified the reinforcement frame of the side gate to reduce the weight of the new truck model deck. It is designed to maintain the strength of 80% or more of the existing gate by (reducing input material). The system and structure rationalization proceeded.
The Z-type spring is a key part of the non-vibration air suspension. The non-vibration air suspension was developed long ago and widely used in developed countries. It has strong durability, provides a smooth ride, protects the vehicle body, and protects luggages from damage in truck. In this study, the structural strength of the Z-type spring was evaluated by computing the maximum displacement and the von Mises maximum stress results from applying the load condition based on the maximum weight of luggage in the rear space of a truck.
In this study, in order to solve the quality problem (Safety accident) that the chain breaks out of the wheel gear due to the problem of the spare tire carrier device, the wheel gear is rotated in such a way that the upper part of the chain is caught on one side of the triangular wheel gear. When falling, the tire falls due to the chain falling off and the chain is caught by the wheel gear so that it cannot bear the tire load and slip occurs. Also, in order to solve the quality problem that the chain is caught (Due to malfunction), the “ㄷ” shaped chain the guide should play the role of guiding the movement of the chain by holding the chain in the direction. The technical development goal is to solve the problem of the chain dropping and the chain hanging from the wheel gear of this product.
In this study, to reduce the weight of cross member assembly for small truck. In order to optimize the design of the cross member structure by changing the equation into the rivet coupling method, The size and the hole spacing of the large sheet plate, the rivet hole size of the large sheet plate, In the structural analysis, we looked at what was going to happen, and the tensile, shear The load test was carried out to investigate the damage caused by the maximum load acting on the rivet. Riveting work, but to improve productivity, we developed automated riveting device using robot To reduce the number of workers, reduce jig transfer and installation time, and reduce load factor. To produce the maximum output of the product.
The aim of this study was to compare the carcinogen classification systems of developed countries or global organizations with domestic system under Industrial Safety and Health Act (ISHA). We selected the representative institutions which had carcinogen classification system such as International Agency for Research on Cancer (IARC), National Toxicological Program (NTP), Environmental Protection Agency (US-EPA), American Conference of Governmental Industrial Hygienists (ACGIH), and European Union (EU). We collected the carcinogen lists issued by 5 institutions, and merged by CAS number of each chemical with Microsoft Access 7.0. We found that confirmed human carcinogens, probable human carcinogens and possible human carcinogens were 34, 179, and 252, respectively. All of the institutions classified chemicals as 2 (NTP), 3 (EU) or 5 (IARC, ACGIH, US-EPA) categories based on the weight of scientific evidences for carcinogenicity and periodically updated the carcinogen list by regular procedure. However, a total of 90 chemicals could be classified as carcinogen under ISHA in Korea. There was no procedure or system which periodically update the carcinogen lists. In addition, the status of carcinogen classification according to regulation was confused. In conclusion, these findings suggest that the carcinogen classification and management system should be amended by consideration of systems of advanced institutions and the domestic regulation system.
In this study, we have developed the database of safety and health information for pesticide active ingredients used in Korea. There were 1,283 pesticide items among which 296 were found to be out of use in current. A total of 349 pesticide ingredients were being used in Korea. The database consists of 32 types of information including chemical characteristics, acute toxicity, chronic toxicity (carcinogenic and reproductive toxicity), specific symptoms by exposure route and first aid. When pesticide ingredients were assessed in terms of key properties such as color, odor, acute toxicity, carcinogenic and reproductive toxicity, they were white, colorless and odorless, in general. When ingredients were classified by category of acute toxicity, 'Non-hazardous' represented 29%, followed by 'Slightly hazardous' at 16%, 'Moderately hazardous' at 14%, 'Highly hazardous' at 5%, and 'Extremely hazardous' at 2%. 85 out of 349, or 24% of ingredients were found to be possibly carcinogenic to human. This database is expected to provide an easy access for farmers, agriculture supervisors, researchers and consumers, and it can ultimately be used as basic data on farmer's safety and health.
This study surveyed the reading discomforts and the reasons for discomfortable reading of the safety and health information (texts and icons) presented on the agricultural vehicles/machines, pesticides, fertilizers, and feeds. Eighty seven people residing in rural area participated in the survey interview. Questionnaire survey showed that the most discomfortable product in reading the texts was pesticides. Forty three (49%) among participants had very-discomfortable or discomfortable in reading the texts used in the label of pesticides, and the main reason for the discomfort was small text size. The reading discomforts in reading the texts (varied from 4 point to 19 point and presented in 50 cm reading distance) showed different pattern according to the age groups. Three age groups (50s, 60s and older than 70s) showed a similar discomfort pattern, but different from the group of 30s and 40s. Forty four people (51%) had a problem in understanding the meaning of the icons and the main reasons were the small size and the difficulty in inferring the meaning of the icons. Thus, the more detailed and practical guidelines for the presentation format, particularly about the text heights and the size of icons, are required. Also, more comprehensive research is needed to investigate the readability and legibility of texts and icons.