• Title, Summary, Keyword: pressing force

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Fabrication of Linear Ultrasonic Motor and Effects of the Pressing Force Applied to Rotors on Characteristics (선형 초음파 전동기의 제작과 특성에 미치는 회전자의 가압력)

  • Lee, Myung-Hun;U, Sang-Ho;Kim, Young-Gyun;Kim, Jin-Soo
    • Proceedings of the KIEE Conference
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    • pp.741-743
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    • 2000
  • In this paper the relationship between the pressing force applied to rotors and the characteristics of ultrasonic motor are discussed. The characteristics of ultrasonic motor using a piezoelectric vibrator were systematically studied. And these were applied to the construction of a card forwarding device. The principle of ultrasonic motor is to use an elliptical motion generated on the side of the vibrator, and the elliptical motion of the ultrasonic motor was obtained by complex oscillation of $L_1-B_4$ mode. As the experimental results. the forwarding speed of the card increased linearly as the pressing force applied to rotors increased. The forwarding speed of the card was 16.0 cm/s when the pressing force applied to rotors was 1 N. The forwarding force of the card increased linearly as the pressing force applied to rotors increased. The forwarding force of the card was 398 mN when the pressing force applied to rotors was 1 N. Therefore, this ultrasonic motor can be expected to be used for card-forwarding device and so on.

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AIx Change According to Pressing Angle and Pressing Force of the Radial Artery Pulse by Tonometry (토노메트리 방식 맥파 측정의 가압 각도와 가압력에 따른 AIx 변화)

  • Cho, JungHee;Jeon, Young Ju;Jun, Min-Ho;Kim, Young-Min
    • Journal of Sensor Science and Technology
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    • v.27 no.4
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    • pp.259-263
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    • 2018
  • A radial artery pulse wave is measured while pressing an artery with constant force. However, pulse waveform measurements vary depending on pressing force and direction. Accurate pulse waveform measurements are important for analysis. Thus, it is necessary to define the measurement range of the permissible force and direction from which a correct pulse waveform is derived. In this study, pulse waves were generated by a pulse wave generator for accurate control. The pulse waves generated for different angles and pressing forces were analyzed. The augmentation index (AIx), which is the most commonly used index for evaluating vascular stiffness, was analyzed. The AIx was measured within ${\pm}6^{\circ}$ of the vessel direction and within ${\pm}8^{\circ}$ perpendicular to the vessel direction with a force that was 25% or more of the pressing force at which the maximum pressure wave was generated. We identified the applicable pressing force and angle range by analyzing the effect of pressing angle on the pulse wave. The AIx analysis performed using the pulse wave measurement device is reliable and reproducible.

Relationship between Movements of the Foot and Electromyographic Activities of Lower Leg Muscles in Young Women (젊은 여성의 발동작과 몇몇 하퇴근 근전도와의 관계)

  • Choe, Myoung-Ae;Shin, Dong-Hoon
    • The Korean journal of physiology & pharmacology
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    • v.18 no.1
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    • pp.81-96
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    • 1984
  • As the crippled persons work mostly in a sitting position and would be engaged in a foot-pressing job, it is necessary to assess their degree of participation of important muscles in various modes of foot activities. In this regard, it deems to be urgent to establish the reference standards for healthy persons. The present study has been undertaken to determine the degree of participation of the M. tibialis anterior, M. gastrocnemius and M. soleus in heel pressing, foot-flat pressing and forefoot pressing motion under varying forces, and in order to compare the electrical activities of three muscles with each other, and to analyse the time sequence between force and appearance or disappearance of EMG recording. Sixty-three healthy young women ranging from age of 18 to 23 were examined. The results obtained were as follows: 1. Participation of three muscles in foot movement under varying forces: A) Both gastrocnemius muscles or left soleus muscle did not contribute to heel pressing motion. Activity of both tibialis anterior muscles was the greatest among three muscles at heel pressing motion and the degree of their activities was proportional to force. B) Activities of left tibialis anterior muscle and both gastrocnemius muscles were negligible under 3 kg force at foot-flat pressing movement. Left gastrocnemius muscle did not contribute to foot-flat pressing under 6 or 9 kg force. Although activities of both soleus muscles and both tibialis anterior muscles were small, the degree of their activities increased with force at foot-flat pressing movement. C) Activities of both tibialis anterior muscles were negligible under 3 kg force at forefoot pressing motion. Activity of both soleus muscles was the greatest among 3 muscles and the degree of their activities increased with force at forefoot pressing motion. Both tibialis anterior muscles participated in forefoot pressing motion with severe exertion. 2. Electrical activities by foot movement under varying forces : A) Electrical activities were prominent in both tibialis anterior muscles and the level of their activities was linear with force at heel pressing motion. The degree of participation of both soleus muscles was small at heel pressing motion. B) Electrical activity of tibialis anterior muscle was the greatest among 3 muscles at foot-flat pressing movement and was followed by that of soleus muscle. Level of electrical activities increased with force in left soleus muscle and right tibialis anterior muscle at foot-flat pressing movement. C) Electrical activity of both soleua muscles was the greatest among 3 muscles at forefoot pressing movement and that of tibialis anterior muscle was next to soleus muscle. Level of electrical activities was proportional to force in left tibialis anterior muscle, right gastrocnemius muscle and both soleus muscles at forefoot pressing movement. 3. Time between starting signal and initiation of contraction of heel pressing and forefoot pressing motion in 3 muscles was longer than that of foot-flat pressing movement. Time of relaxation in 3 muscles was longer than that of contraction under varying forces. EMG recording appeared before initiation of contraction in both tibialis anterior muscles at heel pressing motion and in both soleus muscles at forefoot pressing movement under varying forces. Time of initiation of contraction was similar in both sides of tibialis anterior muscles under varying forces and time of onset of contraction at foot-flat pressing motion was the shortest. 4. Forefoot pressing movement would be encouraged in paralysis of tibialis anterior muscle, while heel pressing motion would be encouraged in paralysis of triceps surae muscle.

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Enslaving Effects on Finger Pressing Speed (손가락 누르기 속력에 따른 Enslaving 효과)

  • Woo, Byung-Hoon
    • Korean Journal of Sport Biomechanics
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    • v.17 no.3
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    • pp.217-224
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    • 2007
  • This study was to investigate the effects of enslaving on finger-tip force of other fingers on finger pressing speed. We hypothesized that the effects depend on finger pressing speed, and the fingers proximity and are larger for fingers that are closer to each other. Six healthy, right-handed subjects(age: $27.1{\pm}4.3yr$, height: $175.4{\pm}7.2cm$, weight $71.3{\pm}5.8kg$) participated in the experiment. Each finger showed no significant on task finger speed. In the tasks with two neighboring fingers (e.g. middle and ring finger tasks), the index and middle fingers showed larger forces than the other neighboring fingers. During the index and little finger tasks, the enslaving force magnitude decreased with distance to the task finger (i.e. index finger enslaving force was the smallest during the little finger task).

Quantitative Evaluation of Rehabilitation Therapy Based on a Two-Finger Force Measurement System

  • Kim, Gab-Soon
    • Journal of Sensor Science and Technology
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    • v.23 no.6
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    • pp.357-361
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    • 2014
  • This paper describes the evaluation of the effectiveness of rehabilitation therapy for patients with finger paralysis based on a two-finger force measurement system (TFFMS). The paralyzed fingers can be recovered through rehabilitation therapies. The finger pressing force of the patients can be measured utilizing the TFFMS previously developed by the author [7]. The TFFMS, however, has not been fully adopted as a standard method for evaluating the therapy owing to the lack of a standard protocol. The pressing force of healthy volunteers and patients is analyzed with the TFFMS to explore the feasibility of the TFFMS as an evaluation device. The test confirms that the established standard protocol is useful to quantitatively assess the progress of finger rehabilitation therapy.

Precision Simulation of Drawing Processes Considering Back Pressing or Tension with Artificial Body Force Scheme (인위적 체적력 기법에 의한 후방 가압 및 인장을 고려한 인발공정의 정밀 시뮬레이션 기술)

  • Eom, J.G.;Shim, S.H.;Cho, J.M.;Kim, H.S.;Joun, M.S.
    • Transactions of Materials Processing
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    • v.20 no.6
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    • pp.461-467
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    • 2011
  • An artificial body force method is presented to accurately simulate drawing processes in which back pressing is exerted. A rigid-plastic finite element method is applied together with a numerical scheme to eliminate the numerically incurred plastic deformation in rigid or elastic region, which significantly influences simulation results because it eventually changes reduction of area in drawing. Back tension or compression is applied by body force at the rear part of material to obtain numerically stable solution. Two typical examples are shown, a drawing process with back tension applied and a tube drawing with a fixed plug and back pressing applied.

Effect of Pressing Force Applied to a Rotor on Revolution Characteristics in the Windmill Type Ultrasonic Motor (풍차형 초음파 전동기의 회전자에 인가된 힘이 회전특성에 미치는 영향)

  • 김영균;김진수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.5
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    • pp.390-395
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    • 2000
  • The ultrasonic motor have recently begun to be used for certain unique practical utilizations in the fields of industrial medical consumer and automotive applications. Ultrasonic motor stimulated to ultrasonic oscillations by piezoelectrics to drive a rotor via friction contact. The metal and ceramic composite component was used as the stator element to generate ultrasonic vibrations. The ultrasonic motor used here was the windmill type ultrasonic motor operated by single-phase AC source. The windmill type ultrasonic motors has only three components; a stator element of two windmill shape slotted metal endcaps a rotor and a bearing. In this paper a prototype motor with 11.35 mm diameter was fabricated then relationship between the pressing force applied to a rotor and the rotation characteristic of windmill type ultrasonic motor are investigated when stator’s slots was changed from 4, 6, 8 and thickness changed from 0.15, 0.20 mm, respectively. Optimum pressing force applied to a rotor in the six stators was 1.2 mN.

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A Study on Pressing Conditions in the molding of Aspheric Glass Lenses for Phone Camera Module using Design of Experiments (DOE를 적용한 카메라폰 모듈용 비구면 Glass 렌즈의 가압성형조건 연구)

  • Kim, Hye-Jeong;Cha, Du-Hwan;Lee, Jun-Key;Kim, Sang-Suk;Kim, Jeong-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.8
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    • pp.720-725
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    • 2007
  • This study investigated the pressing conditions in the molding of aspheric glass lenses for the mega pixel phone camera module using the DOE method. Tungsten carbide (WC; Japan, Everloy Co., 002K),which contained 0.5 w% cobalt (Co), was used to build the mold. The mold surface was ultra-precision ground and polished, and its form accuracy (PV) was 0.85um in aspheric surface. We selected four factors, pressing temperature, force and time of first step, and force of second step, respectively, as the parameters of the pressing process. in order to reduce the number of experiments, we applied fractional factorial design considering the main effects and two-way interactions. The analysis results indicate that the only two main effects, the pressing temperature and the time of pressing step 1, are available for the form accuracy (PV) of the molded lens. The analysis results indicated that the best combination of the factors for lowering the form accuracy(PV) value of molded lens was to have them at their low levels.

Development of Force Measuring System using Three-axis Force Sensor for Measuring Two-finger Force (3축 힘센서를 이용한 두 손가락 힘측정장치 개발)

  • Kim, Hyeon-Min;Yoon, Jong-Won;Shin, Hee-Suk;Kim, Gab-Soon
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.9
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    • pp.876-882
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    • 2010
  • Stroke patients can't use their hands because of the paralysis their fingers. Their fingers are recovered by rehabilitating training, and the rehabilitating extent can be judged by measuring the pressing force to be contacted with two fingers (thumb and first finger, thumb and middle finger, thumb and ring finger, thumb and little finger). But, at present, the grasping finger force of two-finger can't be accurately measured, because there is not a proper finger-force measuring system. Therefore, doctors can't correctly judge the rehabilitating extent. So, the finger-force measuring system which can measure the grasping force of two-finger must be developed. In this paper, the finger-force measuring system with a three-axis force sensor which can measure the pressing force was developed. The three-axis force sensor was designed and fabricated, and the force measuring device was designed and manufactured using DSP (Digital Signal Processing). Also, the grasping force test of men was performed using the developed finger-force measuring system, it was confirmed that the grasping forces of men were different according to grasping methods.

Thermal-Structural Coupled Field Analysis of the Circumferential Pressing Type Brake Disc (원주가압형 브레이크 디스크의 열-구조 연성해석)

  • Kim, Hyeong-Hoon;Lee, Seong-Wook;Han, Dong-Seop;Han, Geun-Jo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.4
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    • pp.69-74
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    • 2008
  • The heat generated by the brake system of vehicles results in reduction of friction force on the brake surface and vibration during a braking. To solve these problems, extensive research for the brake shape has been conducted such as drilling cooling holes on the brake disc, accommodating ventilated holes and etc. In this study, we suggest the circumferential pressing type brake disc in order to improve its cooling performance. In order to compare the cooling-down efficiency between the conventional side-pressing type and the circumferential-pressing type, we adopted the FMVSS 105-77 as thermal analysis conditions and This newly proposed concept has been verified using Thermal-structure Coupled Field Analysis along with comparative analysis with the existing ventilated disk.