http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 정준기 (검색결과 889 건)
- 무료
- 기관 내 무료
- 유료
-
-
AE 신호에 의한 선삭과정의 칩형성기구 예측에 관한 연구
鄭準基 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.5 No.-
In metal cutting, untended machining is being realized to increase the efficiency of working. As the unmanned automation comes true, the friction and abnormal state of machine tools are being closed up as important matters. The method using AE(Acoustic Emission) has more merits like convenience in handling, sensitivity in signaling, etc, than any other method. Therefore, the application to detecting the wear from machine tools has been tried and the method of detecting the value of AErms Volt has been made use of to study the wear of machine tools. However, in high-speed cutting, occurence of chip breaking as well as wear of tools has become a important problem. Chip rupture is a crucial factor of manufacturing system's stability. In this study, AE signal has been detected and analyzed from chip rupture of turning process. Thus, at the result of experiments to detect the formation of chip by analyzing AE signals, the conclusion like the following are obtained, by way of adjusting the threshold value, it is possible separate and detect signals from continuous AE signals and burst AE signal. The count rate of burst AE signal is directly related with the formation of chip generated. It is possible to detect the chip formation by use of event count rate of burst AE signal.
-
鄭準基 弘益大學校 科學技術硏究所 1992 科學技術硏究論文集 Vol.2 No.-
Acoustic emission sensing is found to be very promising for monitoring plstic deformation, tool wear, tool chipping,qr friction induced chatter. All these factors haveqr a certainqr contribution to theqr final surfaceqr roughness in machinred workpieces. As a result,qr AE should contain the information about what makes the machined surface roughness deviate from theoretical values. Consequently, a properly designed AE sensingqr scheme should be a good candidate for on-line monitoring of surface finish in and may cause the scrapping of the workpiece which waste ther long cutting time andqr substantially reducer the efficiency. If the surface generation mechanisms can be monitored during the rough cutting stage of the start of the finishing stage, any malfunction of the tools or machines can be detected and corrected before the final surface is generated. That will dramatically increase the effectiveness of finishing processes. Therefore, the aim of this study is to evaluate the possibility of using AE technologies to develop an online surface finish monitoring system. In the beginr of this chapter, surface roughness monitoring based of measured acoustic emission in finish turning of steel is evaluated. Several signal processing schemes are applied to the raw AE signals to reveal the information related to the changes of cutting mechanisms and thereby deterioration of surface finish.
-
鄭準基 弘益大學校 1987 弘大論叢 Vol.19 No.2
Chatter vibration is considered as a linear single degree of freedom spring mass damper system 'with forces acting upon it. The effects of the equivalent spring constant, mass and damping ratio of the system an the amplitude of the chatter vibration are qualitatively investigated in relation to the cutting prccess which provides the system with the exciting forces. Cutting experiments have been carried out to evaluate the validity of the theoritical considerations using the modified toolpost. The comparison between the theoretical predictions and the experimental results shows a good qualitative agreement. In the present study, the following conclusions are made. The modified tool-post model for chatter vibration can be quantified as a linear single degree of freedom vibration system. Chatter frequency is higher than the natural frequency of the tool-post. And increase in the equivalent damping ratio and the equivalent spring constant causes the decrease in the gain of the frequency response of the tool-post at the chatter frequency, which reduces the amplitude of the chatter vibration.
-
-
鄭準基,沈昇天 弘益大學校 科學技術硏究所 2004 科學技術硏究論文集 Vol.15 No.-
The feasibility of application of the rotary carbide tools in the machining of aluminium alloys is studied in this paper. For the experiment, a new rotary tool holder has been designed and manufactured. Experiments were performed using Taguchi methods and regression analysis to analyse the influence of various factors and their interactions on the cutting characteristics of rotary carbide tools during machining. It turns out that the inclination angle has the greatest influence on the cutting force and the depth of cut has a clear effect on the surface roughness. The cutting force and surface roughness can be estimated using an equation proposed in this paper, which will be well matched to the data of physical experiments.
-
-
음향방출신호 감지에 의한 공구마모와 표면거칠기 사이의 관계 연구
鄭準基 弘益大學校 科學技術硏究所 1993 科學技術硏究論文集 Vol.3 No.-
AE signal contains the informations the information about what makes the machined surface roughness decrease and deviate from theoretical values. So, a properly designed AE sensing scheme should be used to investigate the surface finish at the on-line monitoring condition in precision machining On The other hand, any defect existing on the tools will deteriorate the surface finish and may cause the scrapping of the workpiece which waste the long cutting time and substantially reduce the efficiency. If the surface generation mechanisms can be related with the tool condition during the rough cutting stage of the start and the finishing stage, any malfunction of the tools or machines can be detected and also can be corrected before the final surface is generated by changing the tool or cutting conditions. In this reason, AE signals were sensed and analyzed using various signal processing technique to correlate the surface qualities with the tool wear conditions during the actual cutting condition.
-
-
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
