• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.224-229
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• 2008

With the wide use of mobile phones, a paging signal by a sound transducer acts as an environmental noise on many occasions, thus necessitating an alternative paging signal by a vibration motor. Conventional vibration motors employ three-phase windings with mechanical brushes for commutation. In this paper, a new one-phase brushless and sensorless vibration motor is introduced utilizing digital signal processor chips in cell-phones. For electromagnetic field analysis, two-dimensional modeling can be implemented to determine the back electromotive force using axisymmetric boundary conditions. Geometric design parameters, such as coil pitch and magnet pitch. are considered for performance optimization. Through the experiments, it is shown that the proposed design has the equivalent performance with reduced number of parts, thus enhancing manufacturing productivity and reducing manufacturing cost.

• 기술혁신연구
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• 제23권4호
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• pp.245-287
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• 2015

아키텍처 혁신은 급진적 혁신과 달리 기술적 불연속성의 정도는 낮지만 제품 아키텍처의 변경을 통한 기술적 성능개선 폭은 큰 혁신으로 이해되고 있다. 신생 산업의 초기, 급진적 혁신 제품의 개발에 성공한 기업은 이후, 열등한 아키텍처 효율성 문제를 극복하지 않으면 더 이상 기술적 성능 개선이 둔화되는 시점에 도달하게 된다. 이 지점에서는 급진적 혁신 단계에서의 열등하지만 창의성이 깃든 제품 아키텍처의 창출 경험은 오히려 아키텍처 혁신의 장애물로 작용하게 될 수 있다. 본 연구는 아키텍처 혁신 전후의 시장 요구변화와 이에 대한 기술적 해결 전략을 단계모델의 관점과 문제해결 모델의 관점이 결합된 분석틀의 구축을 통해 이해해보고자 하였다. 한국의 중소기업 자화전자(주)는 산업 초창기 휴대폰에 장착되는 진동모터의 급진적 혁신에 성공 후 아키텍처 혁신과 연관된 장애물들을 극복함으로써 마침내 자신이 개발한 진동모터의 본격적 확산에 성공할 수 있었다. 본 연구는 진동모터의 개발과정에 대한 능동적 참여관찰을 통해 단일 사례를 종단적으로 깊이 연구함으로서, 이 과정이 어떻게 진행되었는지를 이해하고자 하였다.

• 한국소음진동공학회논문집
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• 제13권11호
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• pp.875-881
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• 2003

The received signal of a mobile phone is normally sensed through two independent means which are the sound generation of a speaker and vibration generation of a vibration motor. As an improvement scheme to meet the consumer's demand on weight reduction and miniaturization of a mobile phone, the design and development of an integrated vibration and sound generating device are performed in this research. To this purpose, the optimal shapes of the voice coil. the permanent magnet and the vibration plate are designed, and the excitation force applied to the vibration system of the new device is estimated and verified through theoretical analyses, computer simulation, and experiments using an expanded model. In addition, vibration performance comparison of the device with the existing vibration motor is performed, and from the overall process, therefore, the method and procedure for the vibration performance analysis of the integrated vibration and sound generating device are established.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.218-223
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• 2008

Cell-phone becomes a necessary communication device in modern society. However, a paging signal by a sound transducer often acts as an unpleasant noise, thus necessitating a paging signal by a vibration motor. The conventional flat type vibration motor uses three-phase windings with three phase coils. In this article, a new design of a vibration motor using a V connection with two phase coils is presented, increasing mass productivity. For electromagnetic field analysis, due to the motor symmetry, two-dimensional modeling can be implemented for fast computation, and performance is predicted by the finite element method. The winding distribution angle turns out to be the most important design parameter for the elimination of dead points, and a new coil configuration is suggested which has no adverse effect on motor size and weight. Experimental tests of vibration confirm the validity of the proposed design.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 추계학술대회 논문집
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• pp.101-104
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• 2000

Milli-structure components are classified as component group whose size is between macro and micro scale. that is, about less than 20mm and larger than 1mm. The forming of these components has a typical phenomenon of bulk deformation with thin sheets because of the forming size. In order to conventional metal forming, where numerical process simulation is already idly applied, the micro-forming process is characterized by some scale effects which have to be considered in an advanced process simulation. milli-structure rectangular cup drawing is analyzed and designed using the finite element method and experiment. The result of the finite element analysis is confirmed by a series of experiment.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.471-476
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• 2001

Milli-structure components ate classified as a component group whose size is between macro and micro scales, that is, about less than 20mm and larger than 1mm. The forming of these components has a typical phenomenon of bulk deformation with thin sheets because of the forming size. In this study, milli-structure rectangular cup drawing is analyzed and measured using the finite element method and experiment. Generally, milli-structure containers or cases like cellular phone vibrator consist of rectangular-shaped drawing to save installation space. A systematic approach is established for the design and the experiment of the forming processes for rectangular milli-structure cases. To verify the simulation results, the experimental investigations were also carried out on a real industrial product. The numerical analysis by FEM shows good agreement with the experimental results in view of the deformation shape of the product.