著者

永島 唯哉 池田 生馬 岩附 信行

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.85, no.873, pp.18-00439, 2019 (Released:2019-05-25)

参考文献数

13

被引用文献数

1

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When one rides a car on a gravel road, a noise due to collision of gravels rolled up by tires makes him uncomfortable. The collisions are assumed as random impacts with respect to mass, collision time, position, velocity, angle and so on. In order to probabilistically estimate the noise, the time history of impact force in the case where a force sensor on a rigid pendulum hits a peripherally clamped thin rectangular plate is precisely measured for various impact speeds, angles and positions. The vibration response and sound pressure radiating from the plate are then estimated with the measured impact forces based on Rayleigh-Ritz method and impulse response method. It was then revealed that the time history of impact force could be represented with a certain time function for any impact speeds, angles and positions and that the component of the impact force perpendicular to the plate determined the maximum of the impact force. The time history of impact force can also be approximated as a superposition of the extreme function and Gaussian function. The estimated vibration acceleration of the plate and sound pressure agree very well the measured values. The noise generated by random impacts was estimated probabilistically. It was found that the noise strongly depends on the natural vibration modes of the plate.

著者

木村 直人 岩附 信行 池田 生馬

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.863, pp.18-00092, 2018 (Released:2018-07-25)

参考文献数

12

被引用文献数

2

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Linkage mechanisms with 1 DOF consisting of links and lower pairs cannot completely generate the specified output motion. In order to solve that problem, the novel kinematic pair with 1 DOF is developed. This kinematic pair consists of two surfaces in line contact with each other and can generate relative rolling motion along the specified spatial trajectory. Thus, it is called the spatial rolling contact pair. The relative rolling motion along an arbitrary trajectory is specified so as to satisfy the kinematic condition of the spatial rolling motion. Rolling contact surfaces which can generate the specified motion are designed based on ruled surfaces of the instantaneous screw axis. Some norms to evaluate stability of rolling contact between designed pairing elements are introduced, and the pairing elements are constrained by many linear elastic elements so as to satisfy them. Some examples of the proposed kinematic pair are designed, and one of them is manufactured as a prototype. By some experiments, it is confirmed that the prototype generates the specified rolling motion and keeps rolling contact by designed elastic constraint. Finally, it is revealed that a spatial 4-bar mechanism with the spatial rolling contact pair can completely generate the specified output motion and can be synthesized more easily than the mechanism synthesized by conventional methods.