• 터널과지하공간
• /
• 제32권6호
• /
• pp.386-396
• /
• 2022

로드헤더에 미치는 변수의 영향력을 분석하기 위해 픽커터 절삭시험 관련 참고문헌들을 조사하였고, 수록된 데이터들을 수집하였다. 입력 인자는 일축압축강도, 절삭 깊이, 절삭 간격, 받음각, 비틀림각, 출력 인자는 비에너지, 절삭력, 수직력으로 결정했다. 입력 인자와 출력 인자로 분류 후 실험계획법을 작성하였고 분산분석을 이용해 변수들에 대한 기여도를 조사하였다. 그 결과, 절삭력과 비에너지에 가장 큰 영향을 미치는 요인은 일축압축강도와 절삭 간격으로 분석되었다.

• 한국정밀공학회지
• /
• 제14권4호
• /
• pp.38-45
• /
• 1997

A new dynamic model for the cutting process inb the end milling process is developed. This model, which describes the dynamic response of the end mill, the chip load geometry including tool runout, the dependence of the cutting forces on the chip load, is used to predict the dynamic cutting force during the end milling process. In order to predict accurately cutting forces and tool vibration, the model which uses instantaneous specific cutting force, inclueds both regenerative effect and penetration effect, The model is verified through comparisons of model predicted cutting force with measured cutting force obtained from machining experiments.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집A
• /
• pp.724-729
• /
• 2000

In end milling process the undeformed chip thickness and the cutting force components vary periodically with phase change of the tool. In this study, up end milling process is transformed to the equivalent oblique cutting. The varying undeformed chip thickness and the cutting force components in end milling process are replaced with the equivalent average ones. Then it can be possible to analyze the chip-tool friction and shear process in the shear plane of the end milling process by the equivalent oblique cutting model. According to this analysis, when cutting SM45C steel, 72% of the total energy is consumed in the shear process and the balance is consumed in the friction process.

• 대한기계학회논문집A
• /
• 제25권10호
• /
• pp.1520-1527
• /
• 2001

In end milling process the undeformed chip thickness and the cutting force components vary periodically with phase change of the tool. In this study, up end milling process is transformed to the equivalent oblique cutting. The varying undeformed chip thickness and the cutting force components in end milling process are replaced with the equivalent average ones. Then it can be possible to analyze the chip-tool friction and shear process in the shear plane of the end milling process by the equivalent oblique cutting model. According to this analysis, when cutting SM45C steel, 72% of the total energy is consumed in the shear process and the balance is consumed in the friction process.

• International Journal of Precision Engineering and Manufacturing
• /
• 제3권1호
• /
• pp.76-82
• /
• 2002

This paper presents an experimental study of the effect of cutting tool materials on surface quality when turning hardened steels. Machining tests on a lathe are performed using polycrystalline cubic boron nitride (PCBN) and ceramic tools at various cutting conditions without coolant. From the experiments, it is observed that the radial force is the largest force component regardless the type of tool used. The specific cutting energy for the hard turning is estimated to be considerably smaller than the specific grinding energy. It is also found that cutting force and surface roughness with the PCBN tools are higher and better than those with the ceramic tools under the same cutting condition. It is due that the PCBN tools transfer the generated heat more effectively than the ceramic tools due to their higher thermal conductivity. The optimal cutting conditions for the best surface quality are selected by using an orthogonal array concept.

• 대한기계학회논문집
• /
• 제17권9호
• /
• pp.2214-2222
• /
• 1993

With the use of the NC machine tool, the unmanned production system has been growing recently in the manufacturing field. This there are problems with monitoring adequate tool fracture during the cutting process efficiently. This study was planned and carried out to discover a way of monitoring tool condition in NO-LINE systems during the cutting process. The acquisition of data in cutting force and tool wear has been made in the section examined, to extract the RMS value of the cutting force as specific factors in the cutting process. The fluctuation of the RMS characteristics. From the results, it has been shown that the fluctuation of the RMS values for the cutting force has a close relation to flank wear.

• 한국공작기계학회논문집
• /
• 제13권4호
• /
• pp.9-15
• /
• 2004

A reasonable analysis of cutting force in end milling may give much advantage to improvement of productivity and cutting tool life. In order to analyze cutting force, the cutting dynamics was modelled mathematically by using chip load, cutting geometry, and the relationship between cutting forces and the chip load. The specific cutting constants of the cutting dynamics model were obtained by average cutting forces, tool diameter, cutting speed, feed, axial depth, and radial depth of cut. The model is verified through comparisons of model predicted cutting forces with measured cutting forces obtained from machining experiments. The results showed good agreement and from that we could predict reasonably the cutting forces in end milling.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1998년도 제28회 추계학술대회
• /
• pp.343-349
• /
• 1998

A modeling of machined geometry and cutting force was proposed for the case of round shape machining, and the effects of internally machined profile are analyzed and its realiability was verified by the experiments of roundness tester, especially in boring operation in lathe. Also, harmonic cutting force model was proposed with the parameter of specific cutting force, chip width and chip thickness, and in this study, we can see that bored workpiece profile was also mapped into cutting force signal with this model. In general, we can calculated the theoretical lobe profile with arbitrary multilobe. But in real experiments, the most frequently measured numbers are 3 and 5 lobe profile in experiments. With this results, we can predict that these results may be applied to round shape machining such as drilling, boring, ball screw and internal grinding operation with the same method.

• 한국생산제조학회지
• /
• 제7권2호
• /
• pp.40-46
• /
• 1998

In order to achieve high flexibility in manufacture, chip control is one of the most serious problems at present. The continuous type chip (uncontrolled chip), which interrupts the normal cutting process and damages the operator, tool and workpiece have a higher force ratio. while the controlled chip which is 6 or 9 type and C type, has the values of the force ratio below 0.6 The chips were classified by 4 types. in chip formation and by described chip history during the cutting process. Finally, the feasibility of utilizing force ratios in chip control will be pointed out while comparing generated force signals during the cutting process.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2002년도 추계학술대회 논문집
• /
• pp.192-197
• /
• 2002

In this study, examined the cutting characteristics of alumuminum alloy AC8A-T6 that is used to present car piston materials. And in been holding materials machining empirically escape as result that experiment comparison changing the cutting speed and feed on various condition to choose efficient machining condition. The following results can be summarized from this research. 1. As the cutting speed decreased, principal cutting force and thrust cutting force is increased, and reason that cutting force interacts greatly in the low cutting speed is thought by result by BUE's stabilization. 2. The feed speed and cutting speed increase, friction factor is decrescent and the cause appeared the thrust cutting force is fallen than cutting force relatively because chip flow according to increase of the feed rate is constraint. 3. Though specific cutting resistance grows cutting area and the feed rate are few, the cause was expose that shear angle decreases by rake face of tool gets into negative angle remarkably as wear of a cutting tool or defect part of workpiece is cut. 4. Cutting speed do greatly depth of cut is slow, surface roughness examined closely through an experiment that becomes bad, and know that it can get good surface that process cutting speed because do feed rate by 0.1mm/rev low more than 250m/min to get good surface roughness can.