• Title/Summary/Keyword: Assembly Force

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Optimum Design of Lock Snap-fit Using Design of Experiment (실험계획법을 이용한 이탈방지 스냅핏의 최적설계)

  • Son, In-Seo;Shin, Dong-Kil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.8
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    • pp.378-385
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    • 2017
  • This study investigated the design of a snap fit, which is widely used for fastening plastic parts. We analyzed the assembly mechanism of a lock snapfit, measured the assembly force and separation force based on the design of experiments, and derived a regression equation through an analysis of variance. The response surface methodology was also used. Polybutylene terephthalate was used to fabricate specimens, and the assembly force and separation force were measured using a micro-tensile tester. The length, width, thickness, and interference were considered as factors. A second-order regression model was used to derive the regression equation. The assembly force decreased with increasing length and width, but it increased with increasing thickness and interference. The finite element method was used to analyze the assembly mechanics. The width decreased the assembly force by increasing the ductility. The influences of the factors for low assembly force and high release force were shown to be opposite to each other. It was necessary to design a structure that minimized the assembly force while maintaining an appropriate level of separation force.

Finite Element Analysis of Thermal Fatigue Safety for a Heavy-Duty Diesel Engine (대형디젤엔진의 열적 피로안전도 분석을 위한 유한요소해석)

  • 조남효;이상업;이상규;이상헌
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.1
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    • pp.122-129
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    • 2004
  • Finite element analysis was performed to analyze structural safety of a new heavy-duty direct injection diesel engine. A half section of the in-line 6-cylinder engine was selected as a computational domain. A mapping method was used to project heat transfer coefficients from CFD results of engine coolant flow onto the FE model. The accurate setting of thermal boundary condition on the FE model was expected to result in improved prediction of temperature, cylinder bore distortion, and stresses. Characteristics of high cycle fatigue were investigated by assuming the engine was operated under the following five loading conditions repeatedly; assembly force, assembly force with thermal loading, alternating maximum gas pressure loading at each cylinder combined with assembly force and thermal loading. Distribution of fatigue safety factor was calculated by using it Haigh diagram in which the maximum and the minimum stresses were selected from the five loading cases.

Development of Process of A Force Sensorless Interference fit Assembly Robot System using Sliding Perturbation Observer (슬라이딩 섭동관측기를 이용한 힘 센서리스 억지끼워맞춤 조립로봇시스템 공정개발)

  • Byun, Gyu Ho;Moon, Young Geun;Yoon, Sung Min;Lee, Min-Cheol
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.3
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    • pp.243-251
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    • 2014
  • In inference fit assembly process of the industrial robot, it basically needs the force data. One of the typical methods to get the force data is attaching torque sensors on the robot arm joint or end effector. This is effective way to reduce time delay and to improve preciseness of force control, but this method has several problems. To solve that problem, this paper suggests method which measures assembly force without torque sensor by using the sliding perturbation observer(SPO) and assembly process based on SPO to assemble successfully in inference assembly

Structural Analysis on the Heavy Duty Diesel Engine with Compacted Graphite Iron (CGI를 이용한 대형 디젤엔진의 구조해석)

  • Lee, Jae-Ok;Lee, Young-Shin;Lee, Hyun-Seung;Kim, Jae-Hoon;Jun, Joon-Tak;Kim, Chul-Goo
    • Proceedings of the KSME Conference
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    • pp.602-607
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    • 2007
  • The heavy duty diesel engine must have a large output for maintaining excellent mobility. The compacted graphite iron (CGI) is a material currently under study for the engine demanded for high torque, durability, stiffness and fatigue. In this study, three dimensional finite element model of a heavy-duty diesel engine was developed to conduct the stress analysis by using property of CGI. The FE model of the heavy duty diesel engine section consisting with four half cylinder was selected. The heavy duty diesel engine section include cylinder block, cylinder head, liner, bearing cap, bearing and bolt. The loading conditions of engine are pre-fit load, assembly force and gas force.

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Development of machinery parts test device for the rising high temperature and measuring large and tiny scale torque (기계류부품의 고온상승, 고 토크와 미소토크의 시험장치 개발)

  • Lee, Yong Bum;Park, Hong Won;Lee, Geun Ho
    • Journal of Applied Reliability
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    • v.13 no.1
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    • pp.11-18
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    • 2013
  • For a reliability assessment of machinery parts, accurate performance test, environmental test, life test, etc. are required on the sample. In the performance test conditions of various machinery parts, some problems happen such as needs to rise temperature rapidly with large flow of oil having very low thermal conductivity and to measure very high torque or tiny torque, etc. This study brings out the method to apply heat to rise temperature for large flow of oil without chemical change in a performance test of oil cooler. To measure large scale of torque in a performance test of planetary gearbox of excavator, the method of torque measurement is proposed by replacing the large torque meter priced very expensive. To measure very small torque on lubricated friction, a methode of force balance type test mechanism is introduced for tests of piston assembly.

Identification of Compound Heterozygous Alleles in a Patient with Autosomal Recessive Limb-Girdle Muscular Dystrophy (상염색체 열성 지대형 근이영양증 환자로부터 TTN 유전자의 복합 이형접합성 대립유전자의 분리)

  • Choi, Hee Ji;Lee, Soo Bin;Kwon, Hye Mi;Choi, Byung-Ok;Chung, Ki Wha
    • Journal of Life Science
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    • v.31 no.10
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    • pp.913-921
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    • 2021
  • Limb-girdle muscular dystrophy (LGMD) which is characterized by progressive muscle weakening of the hip and shoulder shows both dominant and recessive inheritances with many pathogenic genes including TTN. This study performed to identify genetic causes of a male patient with late onset (45 years old) autosomal recessive LGMD and atrial flutter. By application of the whole exome sequencing, we identified bi-allelic variants of TTN gene in the patient. One allele had a single missense variant of [c.24124G>T (p.V8042F)], while the other allele consisted of three missense variants of [c.29222G>C (p.R9741P) + c.67490A>G (p.H22497R) + c.75376C>T (p.R25126C)]. The p.V8042F allele was transmitted from his mother, while the other haplotype allele was putatively transmitted from his father. His two unaffected sons had only the p.R9741P. These variants have been not reported or rarely reported in the public human genome databases (1,000 Genome, gnomAD, and KRGDB). Most variants were located in the highly conserved immunoglobulin or fibronectin domains and were predicted to be pathogenic by the in silico analyses. The TTN giant protein plays a key role in muscle assembly, force transmission at the Z-line, and maintenance of resting tension in the I-band. In conclusion, we think that these bi-allelic compound heterozygous mutations may play a role as the genetic causes of the LGMD phenotype.