• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.717-720
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• 2000

Burr makes troubles on manufacturing process due to of deburring cost, quality of products and automation. This paper described the results of experimental study on the influence of the cutting parameters on the formation of exit burrs in face milling. Using the results of experimental study, we classified the burr type and developed data bases to predict burr formation result. This program will be used to predict burr type and geometry at a specified location. Simulation results on deformation strain and temperature are also available. Also algorithm which calculate the exit angle is proposed.

• 한국정밀공학회지
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• 제17권10호
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• pp.132-140
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• 2000

In conventional drilling, burr geometry can be changed according to the variation of drill geometry like point angle, rake angle. Step drilling is proposed to minimize the burr formation in drilling operation. The burr formed in first cutting can be removed in second cutting by the edge in step. The burr formed in second cutting by the edge in step can be minimized according to the change of geometry like, step angle and depth. The mechanism in step drilling is analyzed. Some step drills are applied to drilling the input shaft which is used for vehicle steering. To measure the burr formed in drilling, laser and height gage are used.

• 한국안전학회지
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• 제13권2호
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• pp.164-169
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• 1998

버(burr)는 절삭공정중 공작물의 표면상의 피드마크 뿐만 아니라 측면에도 발생할 수 있다. 이는 공작물의 정밀도와 작업자의 안전의 측면에서 바람직하지 않다. 본 연구에서는 3차원 절삭에서 발생하는 측면버에 관한 실험적 연구를 수행한다. 특히, 측면버의 크기와 절삭 파라메터 사이의 실험적 관계가 설정되며, 이를 통하여 버의 크기를 최소화할 수 있는 방법이 제안된다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.485-491
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• 1999

A burr is formed in every corner of parts as a result of machining, which produces undesirable edge geometry and influence deeply to surface quality of workpiece. Therefore these burrs must be removed certainly. The cost of removing these burrs is directly proportional to their size. Burrs have been among the most troublesome obstruction to high productivity and automation of machining processes. The proper selection of cutting condition and tool geometry will be helpful to reduce the occurrence of burrs. In paper will observe burr formation along helix angle in end milling and certificate experimentally mechanics relation of helix angle and burr formation.

• 한국정밀공학회지
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• 제19권9호
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• pp.166-171
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• 2002

The objective of this paper is to investigate the effect of clearance and the configuration of die system on burr formation by FEM analysis and experimental tests. Compared with casting, forging and machining, shearing has been known, especially in heavy or mass-production industries, as a very economical and fast way to obtain the desired shape Recently, the shearing process becomes widely used in the small and light electronic component manufacturing industries. When shearing a part of sheet metal, the burr formed on the cutting edge is usually unavoidable. The burr would not only degrade the precision of products but also causes additional cost for the deburring process. In this paper, the influence of shearing parameters such as clearance and configurations of the lower pad (ejector) on burr formation is investigated by using the experimental and numerical approach. From the experimental results, it has been shown that the more narrow clearance gives the smaller burr height and the higher shearing forces. The removal of lower holder also makes the sheared surface integrity and the dimensional accuracy become worse. The FEM results (using DEFORM-2D) show good agreement with the experimental results.

• 한국정밀공학회지
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• 제15권4호
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• pp.125-133
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• 1998

The objective of this study is to propose a new approach for modelling of burr formation process during orthogonal cutting when the tool exits the workpiece. This approach is based on the rigid-plastic finite element method combined with the ductile fracture criterion and the element kill method. This approach is applied to orthogonal cutting process to predict the fracture location and the fracture angle as well as the cutting force. To validate this approach, orthogonal cutting tests inside SEM(scanning electron microscope) at very low speed are carried out using A16061-T6 to observe the behavior of the material during the chip and the burr formation. The results of the experiment are compared with those of the finite element simulation.

• Journal of Mechanical Science and Technology
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• 제19권4호
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• pp.968-975
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• 2005

The shearing process for the sheet metal is normally used in the precision elements such as semi-conductor components. In these precision elements, the burr formation brings a bad effect on the system assembly and demands the additional de-burring process, so this imposes high cost on manufacturing. In this paper, we have developed the in-situ auto-aligning precision meso-punching system to investigate the burr formation mechanism and ultimately minimize burr. Firstly, we introduced the punch-die contact sensing method to align the punch and the die at initial state prior to the punching process. Secondly, by using the low-price semi-con­ductor laser, burr formed on the edges is measured intermittently during the punching process. We could, finally, make burr on the sheet metal uniformized and minimized by controlling of the precision X - Y table, $1\;{\mu}m$ resolution, and measuring burr height by semiconductor laser. Experimental results show the validity of our system for pursuing the burr-free punched elements.

• 한국정밀공학회지
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• 제19권2호
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• pp.133-139
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• 2002

A number of experimental studies on burr formation in face milling operations have been pursued. They usually focus on machining parameters such as depth of cut, leed rate, spindle speed and in-plane exit angle. But it if difficult to set the correlation between burrs and the parameters on burr when such parameters are considered at the same time. Therefore, in this paper, acoustic emission (AE) is considered as an alternate way to predict burr types regardless of machining conditions. AE signals during face milling were sampled and processed, then fed into an artificial neural network to classify burr types \\\"on-line\\\".\\\".uot;.

• 산업공학
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• 제18권3호
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• pp.247-252
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• 2005

In the automated production environment in the present days, the minimization of manual operation becomes a very important factor in increasing the efficiency of the production system. The exit burr produced through the milling operation on the edge of workpiece usually requires manual deburring process to enhance the level of precision of the resulting product. So far, researchers have developed various methods to understand the formation of exit burr in cutting process. One method to analytically identify the formation of exit burr was to use the geometrical information of CAD and CAM data used in automated machining. This method, in turn, generated the information resulting from the analysis such as burr type, cutting region, and exit angle. Up to now, the geometrical data were restricted to the single feature and single path. In this paper, a method to deal with the complicated geometric features such as line segment, arc, hole, and spline will be presented and validated using the field data. This method also deals with the complex workpiece shape which is a combination of multiple features. As for the cutting path, multiple tool path is analyzed in order to simulate the real cutting process. All this analysis is combined into a Windows based software and real data are used to validate the program in the conclusion.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1816-1819
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• 2003

As a result of milling operation, we expect to have burr at the outward edge of workpiece. Also, it causes undesirable problems such as deburring cost, low quality of machined surface, and bottleneck in manufacturing process. Though it is impossible to totally remove burr in machining, it is necessary to plan a machining process that minimizes the occurrence of burr. In this paper, a scheme is proposed which identifies the tool path of the milling operation with minimum burr. In the previous research, a Burr Expert System was developed where the feature identification, the cutting condition identification, and the analysis on exit burr formation are the key steps in the program. The Burr Expert System predicts which portion of workpiece would have the exit burr in advance so that we can calculate the burr length of each milling operation. Here, the critical angle determines whether the burr analyzed is an exit burr or not. So the burr minimization scheme becomes to minimize the burr with critical angle. By iterating all the possible tool paths in certain milling operation, we can identify the tool path with minimum burr.