Cassettes are a key component for power transmission and smooth shifting, and their construction consists of sprockets and spiders. The sprocket receives the force generated by pressing the pedal through the chain and rotates the rear wheel. It is a circular part. As the shifting system for efficient driving of bicycles has been developed, chains and sprockets require more complicated shapes than the conventional ones, and researches are being conducted to increase the production efficiency of sprockets. Cr-Mo steel is mainly used as the material for sprockets, but the trend of converting high-performance cassette material to titanium, which is a material with high specific strength, is gradually increasing. In this study, we also studied the molding technology of titanium material for the 5th and 6th stage shape design, the finite element analysis and the mass production using the press mold.

Recently, bicycle has means of effective healthy transportation, and riding the bicycles is considered as popular recreational and sporting activities. Also, the saddle, steering system, driving device and braking device are researched briskly because of consumer’s need for driving performance and comfort. Especially, the importance of a cassette responsible for transmission function by transmitting power to the drive shaft through the chain is very focused. The writer conducted structural analysis for the sprocket of each level using the ANSYS widely used for the analysis. Speed shifting performance was enhanced by minimization / simplification of shifting point through a sort of tooth profile of the cassette. By partitioning a clear value type and other shifting point, it has been modified to enable smooth speed-shifting. In addition, as titanium precision forming process, this study studied the molding technique by blanking and dies forging for mass production of the cassette. so it could be expected that the entire drive train would utilize that in the future. The stamping process capability for thin materials for the mass production of the sprockets is applicable to producing automobile parts, so lightweight component production is likely to be possible through that, for the safety of driving.

본 연구의 목적은 플랫 벤치 프레스에서 하지를 지면에 지지한 자세와 하지를 벤치에 지지한 자세에서의 동작 수행 시 대흉근 및 척추기립근의 근 활성 분석을 통해 벤치 프레스 응용동작에 뒷받침 할 만 한 근거자료를 찾고, 운동수행에 관한 효율적인 기초자료를 제시하는데 있다. 대상자는 아마추어 보디빌더 4명, 헬스 트레이너 2명으로 선정하였다. 측정을 위해 연구대상들의 대흉근과 척추기립근에 표면전극을 부착하였다. 벤치 프레스에 대한 동작구간을 설정하고 하지를 지면에 지지한 동작과 하지를 벤치에 지지한 동작으로 나눠 피험자별 10RM으로 각각 1세트씩 실시하는 방식으로 진행하였다. 데이터는 SPSS 20.0을 통하여 분석하였으며 다음과 같은 결과를 얻었다. 플랫 벤치 프레스 동작 시 하지의 지지 유형이 대흉근에는 영향을 미치지 않았지만, 척추기립근에서는 차이가 나타났다.

서평

A press which has a 20 percent share in machine tools is one of the production facilities. Recently hydraulic press is used to reinforce competitiveness of the manufacturing industry. The press by using metal powder makes products without additional process while conventional processing machine makes products after removing unnecessary parts. In this way, large quantity of products can be produced in a short time. Researches to manufacture products by the press have been proceeding after 1970. In this study, structure and displacement analysis for shape parameters for punch used as the component for hydraulic press was investigated and structural stability was identified based on the results.

The driving efficiency in vehicles depends on a weight lightening of wheels. Lightweight aluminum wheel research has been widespread over the years. Carbon wheels reduce weight by 50% compared to aluminum wheels and have high tensile strength and low heat absorption. This study was investigated to apply the carbon fiber of molding pressure to produce the carbon wheel. Carbon wheel of mold structure analysis was performed.

A press which has a 20 percent share in machine tools is one of the production facilities. The press has been used to make a hole or to bend metal plates. However, recently hydraulic press is used to reinforce competitiveness of the manufacturing industry. The press by using metal powder makes products without additional process while conventional processing machine makes products after removing unnecessary parts. In this way, large quantity of products can be produced in a short time. Researches to manufacture products by the press have been proceeding after 1970. In this study, structure and displacement analysis for punch used as the component for hydraulic press was investigated and structural stability was identified based on the results

In this paper, research development about a bladder press forming system has been carried out for sheet metal forming. The bladder press forming system consists largely of three units as follows forming process unit, driving unit and hydraulic power unit including bladder. Structural analysis of frame of total system by the ANSYS program, flow analysis of bladder by CFX version 14 and hydraulic circuit analysis by AMESim were carried for basic design of bladder press forming system. We can get a good forming results from bladder press system. Developed bladder press forming system will be largely used in aircraft manufacturing industry field.

The objective of this study is to predict the formability of sheet metal for the bladder press. The static implicit finite element method is applied effectively to analyze bladder forming processes using AutoForm software. The material used for forming analysis is AL2024, and the thickness of the plate is 1.6mm, 1.8mm and 2.0mm. Forming force is shown by 101.92kN～87.22kN. The result from the simulation analysis was applied to the bladder press system.

Fruit peels are potential sources of proteases which can help to the proteins digestion and the encapsulation technique is widely used in food industry, which preserves active ingredients in food products by forming coating membrane. In the present study, the effect of addition of encapsulated fruit peels (kiwi, T1; pineapple, T2; pear, T3; fig, T4) on the quality stability of press ham was studied during refrigerated storage (1, 15 and 30 days). In the first experiment, the press ham was prepared with either encapsulated fruit peels or fruit peels powder (without encapsulation) and we observed that the press ham formulated with fruit peels powder showed a texture defect, but no change with encapsulated fruit peels probably due to the proteolytic activity of proteases were prevented by the encapsulation. In the second experiment, the press ham were made with 0.1% encapsulated fruit peels or normal press ham (control) and stored at different days as mentioned above. Our results revealed that T2 showed the highest moisture content, while the control had the highest fat content. The press hams made with all types of encapsulated fruit peels had significantly higher hardness value than the control throughout the storage. Additionally, higher taste, texture and acceptability scores were found in the press ham with encapsulated fruit peels than those in the control. Overall, it is suggested that the addition of encapsulated fruit peels into meat products may enhance the protein digestion and absorption during the digestive processes without the negative effect on texture and sensory traits.

The accident which is caused by the press work remains a Permanent obstacle in worker's hand or arms, the disaster ratio is high and the fatal case is many. Mainly Like this accident occurs because the hand to enter with inside of the press die, therefore, basic countermeasure is the safety press. In order to prevent access to mechanical moving part by the hand or any part of the body, it is important to making a safety die design Structurally. It presents the design of the safety press die with suitable structure in the Product's attribute which it had shown in samples, There is a possibility of being difficult because the attribute of safety die design that had present all the productions from research does not agree each other. but because the representative process which is used most at sample had designed, If you were imitates with safety die design base which is presented from this research, It comes to be thought to be the part which can are used at the various sides.

The reduction of setup time is very important in a lot production system. A punch press is a typical system of lot production. This paper describes a case study to reduce setup time of a punch press manufacturing system. Especially, this case study reduce

There are much dangerous machine in worksite. These make the rate of accidents increase. Specially, among them, the Press work has the highest rate of accidents. Therefore, it has been managed by Industrial safety-health law. It is very important to make a special study of work using the dangerous machine. In press work, it is also important to develop safety system program to improve productivity and work safely, In this reaserch, the safety management system is built for the work improvement of the Press. This paper showed method about dangerous machine.

Recently, WRMSD(Work-Related Musculoskeletal Disorders) that can be frequently found among simple and repetitious works has been a big occupational safety issue, and has begun to being studied actively by many Korean researchers. However, those researches have been largely relied on foreign ones, due to the lack of basic data in Korea. In this study, we have tried to search the actual conditions and factors on WRMSD of press workers in a local company. In addition, we examined how the contents of works and postures of the workers affect the disease. It is expected that the data collected in this study will be able to used for planning the preventive measures on WRMSD effectively and for implementing its corresponding programs.

In this study, it was researched a kind of the press machines which had been retained in the domestic press working companies. And then it was analyzed the present conditions with the working types, companies size, the aging types and the continuous working periods. Specially, the purpose of this paper is decreased the industrial accidents of the domestic press working companies by the proposing the safe prevention which are obtained by the analysing the accidential reasons.

In this study, it was researched a kind of the press machines which had been retained in the domestic press working companies. And then it was analysed the present conditions with the working types, the size of companies, the aging types and the continuous working periods. Specially, the purpose of this paper is decreased the industrial accidents of the domestic press working companies by the proposing the safe prevention which are obtained by the analysing the accidential reasons.

The purpose of this paper is to supply the principal methods for the safety in the press industrial accident preventions and the basic analyzing theory in the press industrial accidents. It was reached the press machine installed companys and was analyzed the accident characteristics, types, the worker's working period and the distributed worker's age of the happened the press machine industrial accidents. The direct reasons are almost reasons of the press industrial accidents. But it should be not ignore the indirect reasons of the accidents In this study, it was presented that the safety devices is selected by the amalyzed reasons in the press industrial accidents for the principal accident prevention.

The purpose of this paper is to supply the principal methods for the safety in the press industrial accident preventions and the basic analyzing theory in the press industrial accidents. It was reached the press machine installed companys and was analyzed the accident characteristics, types, the worker's working period and the distributed worker's age of the happened the press machine industrial accidents. The direct reasons are almost reasons of the press industrial accidents. But it should be not ignore the indirect reasons of the accidents In this study, it was presented that the safety devices is selected by the analyzed reasons in the press industrial accidents for the principal accident prevention.