• 소성∙가공
• /
• 제32권6호
• /
• pp.376-383
• /
• 2023

The torsion bar, which is a steering torque sensor, is mounted between the steering pinion and the input shaft in the IPA(input pinion assembly). Accurate torque measurement is important to improve the sense of operation, and the straightness of the torsion bar can affect torque measurement. In this study, the amount of bending was measured and the exact shape was analyzed regarding the bending phenomenon in the press-fitting process for torsion bars. The effect of alignment error was analyzed through finite element forming analysis. Process data analysis was conducted for the double-end press fit model. If there is an alignment error of about 10% of the serration tooth height, the indentation load is reduced by about 10%. If there is an alignment error, the torsion bar is rotated.

• 한국해양공학회지
• /
• 제25권6호
• /
• pp.80-85
• /
• 2011

The Ultrasonic Nanocrystal Surface Modification (UNSM) technology improves the fatigue life of a torsion bar by inducing compressive residual stress on the surface layer. The UNSM is applied to replace the presetting method and shot peening technology. The torsion bar must be changed periodically because of a lack of durability and a phenomenon related to the stress relaxation. The torsion fatigue test specimens were made of DIN17221 material, and the results showed that the fatigue life was 5 times more than under durability test conditions. A comparison test between the commercial vehicles' presetting method and shot peened torsion bar and the UNSM torsion bar showed that the UNSM could replace the presetting method and shot peening.

• 대한기계학회논문집A
• /
• 제36권9호
• /
• pp.979-984
• /
• 2012

Antiroll-bar Assembly는 철도 차량의 롤링을 제어하도록 설계된 정밀 부품이고 안전과 편안한 승차감을 위해 중요하다. Antiroll-bar Assembly의 주부품인 토션바는 소모품으로써 프랑스에서 전량 수입되고 있다. 따라서 비용절감과 성능향상을 위해 국내 환경에 적합한 토션바 국산화 개발이 필요하다. 본 연구에서는 국내 철도에서 측정된 로드 히스토그램을 활용하여 개발된 토션바에 대한 해석 및 시험을 진행하였고, 수입품과의 비교 시험 결과 만족할만한 결과를 얻었다. 또한 토션바의 부식현상을 방지하기 위해서 스테인리스강 소재의 Ring cover를 씌울 수 있도록 설계를 변경하였다. 변경된 설계 안전성은 CAE해석과 마모시험을 통해서 검증하였다. 이 결과 설계변경에 의한 정적 및 피로에 대한 안전성은 큰 차이가 없었다. 그리고 2종류의 스테인리스강 중에서 내마모성이 우수한 소재를 채택하였다.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
• /
• pp.97-98
• /
• 2011

This paper is about the study of a new exo-skeleton device applying a gravity compensator. The exo-skeleton devices is to reduce the external torque applied to the human body joint for the purpose of helping the disabled, reducing heavy payload for industry workers or military soldiers. Most of the exoskeleton devices are actuated by the motors, but motors are limited in energy such that a short durability is always a big problem. In this paper, an exoskeleton device using a new gravity compensator based on a torsion bar is proposed to reduce the torque load applied to human body joints. The exoskeleton device is designed for the lower body of human. Analyses on the torsion bar spring and link of the exoskeleton device using FEM method were performed. To reduce the applied torque to the human joint, a torsion bar gravity compensator is applied to the exoskeleton. The effect of the torsion bar compensator for the exoskeleton device was verified through load test using developed test equipment.

• 대한기계학회논문집A
• /
• 제32권2호
• /
• pp.170-176
• /
• 2008

Anti roll bar model for real time multibody vehicle dynamics model has been proposed using kinematic constraint. Anti roll bar have been modeled by kinematic relationship, and mass properties are neglected. Relative angle of torsion bar spring is computed by constraint about drop-link using Newton-Raphson iteration, and then the torque of torsion bar spring can be computed with the angle and torsion spring stiffness. Finally anti roll bar force acting on both knuckle can be calculated. To validate the proposed method, half car simulations of McPherson strut suspension and full car simulations are also carried out comparing with the ADAMS vehicle model with anti roll bar. CPU times are also measured to see the real-time capabilities of the proposed method.

• Journal of Advanced Marine Engineering and Technology
• /
• 제36권4호
• /
• pp.467-475
• /
• 2012

이 논문에서는 비틈 봉을 기반으로 한 중력보상기가 적용된 새로운 외력증강기를 이용하여 인체 다리관절에 작용하는 부하를 경감시키는 방법에 대해 제안한다. 비틈 봉 특성을 추정하고 측정하기 위하여 설계와 구조 해석을 행하였다. 설계와 구조해석을 바탕으로 매우 경량이고 소형인 새로운 외력증강기를 개발하였다. 구조해석은 외력증강기를 매우 경량으로 하기위해 최적두께의 링크에 대한 FEM해석을 행하였다.

• 호남수학학술지
• /
• 제20권1호
• /
• pp.121-133
• /
• 1998

We find some properties of the pro-torsion products. Under the suitable conditions, we also show that the map ${\bar{H}}_P({\chi};G){\rightarrow}{\bar{H}}_p^{s(r)}({\chi};G)$ is an isomorphism and the n-th homotopy group of X is isomorphic to the n-th ${\check{C}}ECH$ homology group.

• 대한수학회보
• /
• 제50권1호
• /
• pp.83-96
• /
• 2013

Let K be a number field and fix a prime number $p$. For any set S of primes of K, we here say that an elliptic curve E over K has S-reduction if E has bad reduction only at the primes of S. There exists the set $B_{K,p}$ of primes of K satisfying that any elliptic curve over K with $B_{K,p}$-reduction has no $p$-torsion points under certain conditions. The first aim of this paper is to construct elliptic curves over K with $B_{K,p}$-reduction and a $p$-torsion point. The action of the absolute Galois group on the $p$-torsion subgroup of E gives its associated Galois representation $\bar{\rho}_{E,p}$ modulo $p$. We also study the irreducibility and surjectivity of $\bar{\rho}_{E,p}$ for semistable elliptic curves with $B_{K,p}$-reduction.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.1009-1010
• /
• 2012

• 한국기계가공학회지
• /
• 제11권3호
• /
• pp.86-91
• /
• 2012

Door effort was calculated for a new door checker with torsion bar spring and integrated checker case by FE analysis. A hybrid checker arm which has peaks and valleys only on the upper surface was adopted to reduce noise in operation and make operation with more distinctive steps. The checker arm was modeled using shell elements to estimate both the longitudinal and the lateral resistance force by checker arm. By combining the checker arm resistance force obtained from analysis and the door self-closing force by the theoretical calculation, door effort was predicted to show the good correlation with test results. In addition the unrolling effect of roller model was investigated and a new roller type for more smooth rolling was studied.