• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.448-451
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• 1986

An automatic welding system is designed for a part of fork lift. The system is composed of articulated type welding robot, welding positioners, shuttle for robot, system controller and welding equipment. From the application of the system, stable weld quality and production cost saving are achieved. In this paper, the hardware features and control structure of the system are presented.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1473-1478
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• 2000

Severe fork-lift truck noise is annoying to an operator as well as one of the noise pollution elements. This paper presents the noise contribution analysis of a cabin type fork-lift truck to identify the major sources and its usage to reduce the interior noise level. The methodologies for this work are sound field analysis, sound intensity test, insertion loss test of duct system and etc. An effective method to suppress interior noise level of fork-lift truck and design guides are suggested.

• 대한안전경영과학회지
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• 제18권1호
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• pp.75-82
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• 2016

According to the statistics, occupational fatal injuries by the fork lifts were about 30 per year in whole industrial. Fork lifts are widely used in various parts of industries to improve the efficiency of the work. In this study, the current regulations to be adequate in industrial site have to be renew in order to prevent the fatal injuries by the fork lifts. Fatal injury analysis were conducted with several accident cases by the fork lifts. For each accident, the causes of the injuries were examined and proper safety measures were proposed. In this study, the fork lift showed a high fatality rate in industrial accidents and no detailed cause analysis of fatal accidents was conducted in terms of unsafe acts or conditions. First, fork lifts were the highest of the machines caused the accidents. In order to prevent fatal injuries by the fork lifts, the tarket was manufacturing industry. Second, the order of the cause of cognitive engineering agenda in the manufacture industrial was visibility, responsibility and affordance, and revision of acts was proposed. Third, there was not a lots of different points of human error between occurrence types and business sizes. Forth, number of fatalities by the attacker was more than by the inducer.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
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• pp.155-160
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• 1996

The vibration analysis of the automobiles has been a good subject for the engineers seeking solutions for more comfortable life. In the area of industrial vehicles, however, the seriousness of the vibration annoyance has not been considered so much. In this paper, a finite element model was built which was good for the low-frequency system(of fork-lift truck), and a forced vibration analysis was obtained for the component of 2n of harmonic orders from engine excitation to this model. Finally, a design optimization upon dynamic responses was made to minimize the vibration acceleration level at selected points representing the vibration level of the whole system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.913-914
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• 2006

In industrial field, electric fork-lift has been mainly powered by batteries which are varied from DC 36V to 80V. Operating electric fork-lift truck depends on stable electric power supplies which are ensured by using Switched Mode Power Supply (SMPS). This paper presents design of SMPS for stable electric power supply. The SMPS has much strength such as high effectiveness, low cost and high stability of output voltage. At the same time, SMPS is small and multi output and has simple design of circuit.

• 한국기계가공학회지
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• 제18권4호
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• pp.62-68
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• 2019

The aim of this study was to interpret the structure and dynamics of a transfer shuttle system as a material supply device for small machine tools. The following conclusions were obtained by performing a structural interpretation of the material supply equipment with respect to workload and the dynamical interpretation of a flexible multibody carriage shuttle. When a 1,000-kg workload was applied to a fork lift, the safety factor was approximately 1.86. To conservatively assess the integrity of the structure, a 1,000-kg workload would be proper. In the case of a deflection of the fork system, the width increased with increasing time. The greatest deflection occurred at 5.5 s, which was the largest increase in the time point of the fork system.

• 한국기계가공학회지
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• 제17권2호
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• pp.124-129
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• 2018

A forklift is used to lift materials above a height of 2 m. The width of the fork determines the weight of the material it can carry. In this paper, three models of fractured forklifts were analyzed to determine if the fracture was caused by load fatigue due to the width of the fork. The position of the fork was fixed on each model, and a 2.5 ton load was placed at the upper part of the fork. The width distances on each of three models were 500 mm, 750 mm and 1000 mm, and the maximum equivalent stresses were 237.5MPa, 227.62MPa and 230.99MPa, respectively. This analysis demonstrated that as the load increased with use of the wider fork, the fatigue life remained to be nearly equivalent irrespective of fork width among all three models. The results of this study contribute to the durability and safety design of forklifts.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1176-1178
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• 1992

This paper shows enhanced working performance of the battery fork-lift truck by developing the IGBT full bridge dc-dc convertor using one-chip micro-processor. The PWM pulse is generated from a 16 bit one-chip micro-processor for the speed control of DC motor. In order to ensure the operation of IGBT and motor pecewisely, IGBT gate drive circuit was designed by using current limiting IC and hige voltage limit IC. And also It is able to regenerative braking.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.557-563
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• 1997

In order to satisfy the regulations concerned with the noise emission of fork-lift trucks and thereby increase export to the western countries, a noise reduction technique should be developed in the early design stage. In this paper, several noise sources are identified using the sound suppression method and sound intensity measurement, and their contributions to the sound levels at the operator's ears and at the distance of 7m from the vehicle are studied. For each of the major noise producting components, noise abatement alternative are suggested and their effects are analyzed.

• 대한환경공학회지
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• 제27권7호
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• pp.677-685
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• 2005

본 연구에서는 국내외에서 법적, 제도적 측면의 외적 정비뿐만 아니라, 학계 및 산업계의 제품별 사례분석 및 적용 측면에서 활발한 연구가 진행되고 있는 LCA와 DfE기법을 제조공정에 적용하였다. 구체적으로, 지게차 제조공정을 대상으로 LCA 기법을 적용하여 환경부하가 가장 큰 제조공정을 규명하고, 그 공정에 DfE 기법을 적용하여 친환경적인 제조공정을 설계하였다. 지게차 제조공정에 대해 LCA를 수행한 결과, 영향범주별로는 생태독성과 인간독성에 대해, 그리고 공정별로는 제관공정과 도장공정에서 환경부하가 크게 나타났다. 제관공정에서 환경부하를 줄이기는 현실적으로 어렵기 때문에, 도장공정에서 발생하는 환경부하를 저감하고자 하였다. 이를 위해 지게차의 도장공정에 기존에 사용하고 있는 용제형 도료의 고형분 함량을 늘려 high solid형 도료를 개발하여 적용한 결과, 환경영향(LCA의 환경영향지수)가 20% 저감되었다. 또한, VOC발생량은 약 32%, 도료 사용량은 약 20%의 저감효과를 얻을 수 있었다.