• 한국기계가공학회지
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• 제18권5호
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• pp.17-22
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• 2019

In this study, Cermet Reamers for planet carrier was manufactured and the machining characteristics were analyzed through processing experiment. Cermet reamer with ∅14, ∅15, ∅18, and ∅21mm was used and machining characteristics were compared and analyzed by observing tool wear, machining hole dimensions and surface roughness. In the flank wear of the tool, the result is less than 0.2mm, which is the target value for each tool size. The experimental results of the machining hole dimensions show the results of the process control range of 3/100 or less according to the size of the tool. Also, the surface roughness measurement result showed a value of less than $0.5{\mu}m$ in the process control range for each tool size. As a result of observing the experimental results of each ∅, the results satisfied the process standard in both the tool wear, the machining hole dimension and the surface roughness.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.1003-1008
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• 1997

In this paper, the prediction of cutting force and tool deflection in the ball-end milling process are studied. Identifying various cutting region using Z-map, cutting force in the ball-end milling process can be predicted. Cutting force deflects the tool and the tool deflection changes the cutting force. Tool deflection is included in the cutting force prediction. Tool deflecition also causes machining error of the machined surface. A series of experiments were performed to verify the simulated cutting force and machining error.

• 산업경영시스템학회지
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• 제10권15호
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• pp.33-38
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• 1987

In establishing Multi-Stage Machining process inspection procedures, however, where costs of inspection md defective products are often directly measurable, a better method for formulating inspection plans is available. If one of the primary interest of a manufacturing concern is to maximize profits, then optimal inspection plans ought to be selected so as to minimize costs. This paper is aimed to find a methodology of optimal inspection planning in Multi-stage Machining process and to develope a proper algorithm.

• 한국기계가공학회지
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• 제1권1호
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• pp.38-47
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• 2002

Machining quality has been improved with the development of cutting tools. However, it is difficult to obtain a high degree of quality in machining a deep pocket with a long end mill, since machining accuracy is mainly dependent on the stiffness of the cutting tool and tool holder. To improve machining quality in machining a deep pocket using an end mill, the performance by cutting condition compare with others. Owing to this problem, it is necessary to select suitable tool and holder in the deep pocket machining. In this study, the hydraulic holder for the high speed machining is introduced and the performance of that is compared with others according to cutting conditions. The cutting parameters involved were; slenderness ratio in the range of 3 to 6 (L/D), radial depth of cut from 0.01 to 0.05 mm. Cutting force and surface roughness, precision of form were observed during the experiment to investigate cutting state.

• 한국정밀공학회지
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• 제23권8호
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• pp.195-202
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• 2006

High-speed machining (HSM) with excellent quality and dimensional accuracy has been widely used to create 3D structures of metal and plastics. However, the high-speed machining process is not suitable for the rapid realization of 3D thin-walled product because it consumes considerably long time in fixturing process of a work piece. In this paper, an effective rapid manufacturing process is proposed to fabricate 3D thin-walled products directly using HSM, phase change filling and ultrasonic welding. The filling process is useful to hold the thin-walled product during the machining step. The ultrasonic welding process is introduced to make one piece product from two piece parts that are machined by HSM and filling process. The proposed rapid manufacturing (RM) process has been shown that the RM process enables to fabricate the 3D thin-walled products using ABS plastics and aluminum metals from 3D CAD data to functional parts.

• 한국CDE학회논문집
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• 제6권4호
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• pp.244-253
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• 2001

For more complete process planning, machining sequence determination is critical to attain machining economics. Although many studies have been conducted in recent years, most of them suggests the non-unique machining sequences. When the tool approach directions(TAD) are considered fur a feature, both machining time and number of setups can be reduced. Then, the unique machining sequence can be extracted from alternate(non-unique) sequences by minimizing the idle time between operations within a sequence. This study develops an algorithm to generate the best machining sequence for composite prismatic features in a vertical milling operation. The algorithm contains five steps to produce an unique sequence: a precedence relation matrix(PRM) development, tool approach direction determination, machining time calculation, alternate machining sequence generation, and finally, best machining sequence generation with idle times. As a result, the study shows that the algorithm is effective for a given composite feature and can be applicable fur other prismatic parts.

• 한국기계가공학회지
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• 제7권3호
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• pp.67-74
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• 2008

Polycrystalline diamonds(PCD) tools are widely used in machining a large variety of advanced materials. However, the manufacture of PCD tool blanks is not an economical process. The shaping of PCD blanks with conventional machining methods(such a grinding) is long, labor-intensive process. This paper reports experimental investigation of the influence of electrical machining conditions on the metal removal rate of WEDM of PCD. Experimental results show that the longer pulse-on time and the shorter pulse-off time increase the metal removal rate and worsen the surface quality. The smaller grain size of diamond yields the metal removal rate and shows the better surface quality. Higher electrical conductivity of water yields worse surface roughness.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1338-1343
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• 2007

High-efficient machining, which means cutting a part in the least amount of time, is the most effective tool to improve productivity. In this study, a new feed optimization method based on the cutting power regulation was proposed to realize the high-efficient machining in turning process. The cutting area was evaluated by using the Boolean intersection operation between the cutting tool and workpiece. And the cutting force and power were predicted from the cutting parameters such as feed, depth of cut, spindle speed, specific cutting force, and so on. Especially, the reliability of the proposed optimization method was validated by comparing the predicted and measured cutting forces. The simulation results showed that the proposed optimization method could effectively enhance the productivity in turning process.

• 한국기계가공학회지
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• 제2권3호
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• pp.5-12
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• 2003

In order to reduce the lead-time and cost, many useful methods have been applied to rapid prototyping (RP) in recent years. But cutting process is still considered as one of the effective RP methods that have been developed and currently available in the industry. It also offers practical advantages in aspects of precision and versatility. However, traditional 3-axis NC machining has some inherent limitations such as the restriction of tool accessibility and the complex setup. In this work, a new rapid prototyping system with high speed 5-axis machining of plastics has been developed to overcome those limitations. And cutting experiments were conducted to determine the design factors of the system and the cutting conditions of plastics. The architecture of developed system is described in detail and the successful application examples are presented.

• 한국기계가공학회지
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• 제14권4호
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• pp.100-107
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• 2015

Recently, high-efficiency machining in the production of high-value products with a complex shape has constantly been required with the need for hybrid machining. In this study, in addition to the wire-cut E.D.M. and vibration used to present the possibility of a hybrid process by carrying out the aluminum alloy experiment, the hybrid process determines the nature of the surface. The selected experimental parameters are horizontality, waveform, amplitude, peak current, and frequency. The experimental results give guidelines for selecting reasonable machining parameters. The surface roughness was improved by about 20% with increases in the amplitude of the vibration.