• Design & Manufacturing
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• v.9 no.3
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• pp.19-23
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• 2015

Non-pneumatic wheels have been widely used instead of general tube type wheels beause of many reasons, for example, wheel size, price restriction, heavy-duty problem and so on. Almost small size wheels or casters were non-pneumatic type but structural stability was not certified. This paper presents a double structured non-pneumatic wheel, called "smart caster", which consisted with inner and outer wheels connected by chips, and finite element analysis processes were conducted in order to determine important dwsign factors before actual design for mass production. For structural analysis ABAQUS was used under various boundary conditions with incrementally varied loads until 2,000N. Then structural staility was evaluated according to varied loads below ultimate stress. Generally stresses were concentrated at the lower parts of the wheel, and especially contact parts between wheel and ground. In addition, maximum stress appeared at contact parts between the wheel lower part and chips.

• Korean Journal of Materials Research
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• v.24 no.10
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• pp.538-542
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• 2014

Microstructural and mechanical characteristics of Al-6Si-2Cu alloy for lightweight automotive parts were investigated. The test specimens were prepared by gravity casting process. Solution heat treatments were applied to as-cast alloys to improve mechanical properties. The microstructure of the gravity casting specimen presents a typical dendrite structure, having a secondary dendrite arm spacing (SDAS) of $37{\mu}m$. In addition to the Al matrix, a large amount of coarsened eutectic Si, $Al_2Cu$ intermetallic phase, and Fe-rich phases were identified. After solution heat treatment, single-step solution heat treatments were found to considerably improve the spheroidization of the eutectic Si phase. Two-step solution treatments gave rise to a much improved spheroidization. The mechanical properties of the two-step solution heat treated alloy have been shown to lead to higher values of properties such as tensile strength and microhardness. Consequentially, the microstructural and mechanical characteristics of Al alloy have been successfully characterized and are available for use with other basic data for the development of lightweight automotive parts.

• Journal of Mechanical Science and Technology
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• v.19 no.3
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• pp.768-777
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• 2005

This paper shows that the performance of a nonlinear fluid engine mount can be improved by an optimal design process. The property of a hydraulic mount with inertia track and decoupler differs according to the disturbance frequency range. Since the excitation amplitude is large at low excitation frequency range and is small at high excitation frequency range, mathematical model of the mount can be divided into two linear models. One is a low frequency model and the other is a high frequency model. The combination of the two models is very useful in the analysis of the mount and is used for the first time in the optimization of an engine mount in this paper. Normally, the design of a fluid mount is based on a trial and error approach in industry because there are many design parameters. In this study, a nonlinear mount was optimized to minimize the transmissibilities of the mount at the notch and the resonance frequencies for low and high-frequency models by a popular optimization technique of sequential quadratic programming (SQP) supported by $MATLAB^{(R)}$subroutine. The results show that the performance of the mount can be greatly improved for the low and high frequencies ranges by the optimization method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.136-144
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• 1992

Recently, Silicon Nitrde ceramic is regarded as the representative engineering ceramic with the excellent mechanical properties and many functions for mechanical components and parts among various kinds of ceramics in the mechanical industry. But, during the manufacturing of engineering ceramics, there is many volumetric shrinkage coupled with a distortion of the parts which is produced. Due to the requirement for high accuracy of size, form, and surface finish of the components, machining is needed surely. Nowdays, grinding with a resin bond type diamond wheels has been generally applied to machining of the engineering ceramics in the whole world because that it can be conveniently proceeded for workers to dress of tool and made with high reliability in producing factories among many bond type super-abrasive wheels yet. It is important task for attaining prescribed mechanical components with high reliability to observe the grinding mechanism of ceramics as like generation of cracks and chipping of material during process. Because they considerably effects on the strength characteristic of machined mechanical components. In this study, various surface grinding experiments using resin bond type diamond wheels are carried out for Silicon Nitride ceramic. Grinding mechanism of ceramics is observed experimentally and the relationship with various conditions is also attained. Form this experimental study, some useful machining data and information to determine proper machining condition for grinding of Silicon Nitride ceramic is obtained.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.1
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• pp.47-51
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• 2017

Generally, a working excavator has only one directional bucket tilting angle, which is up-forward. However, side direction rotation of the bucket would allow variety of working output. We designed a hydraulic rotary actuator comprising a double rod hydraulic cylinder with a rack-pinion gear set for use in excavator bucket with side tilting mechanism, thus converting the linear to angular motion. The proposed side tilting rotary actuator was designed with parts suitable for medium size of heavy duty excavator. These mechanical parts were inexpensive to purchase and the manufacturing cost was reasonable. The proposed mechanism is potentially useful for excavator with variety of working output.

• Design & Manufacturing
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• v.16 no.1
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• pp.43-49
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• 2022

As technologies in various industrial fields develop, high-quality parts are required. In the past, precision parts were produced by the contact machining method, but the contact machining method has clear limitations. In order to solve this problem, research on a non-contact processing method has been conducted, and laser processing and electric discharge processing are representative. However, the non-contact method has a problem in that productivity is insufficient, and there is a problem that it takes a lot of time to continuously process microholes. Researchers have developed an electron beam drilling equipment for continuous processing of fine holes, and a vaporization amplification sheet to increase the processing efficiency of the equipment. In this study, a cylindrical vaporization amplification sheet using room temperature curing type silicon was fabricated, and the metal distribution and thickness uniformity of the produced sheet were analyzed. In order to manufacture a cylindrical vaporization amplification sheet, an equipment capable of using centrifugal force was developed, and a sample in which metal powder was evenly distributed and a constant thickness was produced.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.73-82
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• 2016

Recently, automobile industries have been developing many structural automotive parts made of thin, high-strength steel strips to produce safer and more environmentally friendly cars. The roll forming process has been considered one of the most efficient processes in manufacturing high-strength steel parts because it is a high-speed process that forms sheets in increments. However, most automotive parts vary longitudinally in their cross-sections. Therefore, it is difficult to apply the roll forming process to automotive parts made of high-strength steel. A variable section roll forming process has been proposed in recent studies. The rotational axes of the forming rolls are fixed, and the forming rolls have three-dimensional shape. As such, the cross-section of the part varies linearly along its length, and the angle between the bend line and longitudinal axis is less than 1 degree. Thus, the rate of cross-sectional variation along the length is relatively small. In this study, the rate of cross-sectional change along the length of a forming roll has been increased. Moreover, the angle between the bend line and longitudinal axis has been increased up to 15 degrees. The variable sections of the forming rolls have been designed for high strength steel parts with a symmetric u-type cross-section that varies linearly and symmetrically along the longitudinal axis.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.502-508
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• 2011

In this paper, we proposed vertical feeding mechanism for a slide parts feeder using the slide type method. This parts feeder of the slide type method have been proposed to suppress the dust generation from the feeding objects. The proposed parts feeder mechanism is composed with the casing hopper, the vertical feeding unit, the in-line feeder and linear shooter unit. And, these mechanisms did modularity through optimum design by means of mechanical and dynamical analysis using the RecurDyn(multi-body dynamics) analysis module. Also were carried out the virtual prototype using the 3-D CAD program. And it had been manufactured as the prototype of the slide parts feeder. The field test for validation of performance was performed directly at the inspection line of bolt and screw. In the field test, this slide parts feeder showed an efficiency of about 1.2 times the bowl feeder. It also showed an epoch reduction in the dust generation compared to the vibration bowl feeder. So this slide parts feeder will be applied useful in the vision inspection system for a screw and bolt.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.4
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• pp.357-364
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• 2017

Metal casting is a process in which molten metal or liquid metal is poured into a mold made of sand, metal, or ceramic. The mold contains a cavity of the desired shape to form geometrically complex parts. The casting process is used to create complex shapes that are difficult to make using conventional manufacturing practices. For the optimal casting process design of sleeve parts, various analyses were performed in this study using commercial finite element analysis software. The simulation was focused on the behaviors of molten metal during the mold filling and solidification stages for the precision and sand casting products. This study developed high-life sleeve parts for the sink roll of continuous hot-dip galvanizing equipment by applying a wear-resistant alloy casting process.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1289-1295
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• 2003

Most industrial products nowadays have been manufactured by being made up of many parts what these are made from various kinds of materials. These parts and goods should be disassembled simply and classified easily by material or kinds of parts for the recycling. But it is not so easy to know how to take disassembly ways and those orders must be known and also analyzed the assembled points and directions of the every part. This research presents an design process for recycling that it will be considering whole design process for recycling about easiness of disassembling units as the prior condition to reuse the parts and used material, and to reduce waste parts.