Bridgestone Corporation

Bridgestone Tire Company Limited

Other

Hitachi, Ltd.

Nissan Motor Company Limited

Hitachi Plant Engineering Construction Co., Ltd.

Topy Industries, Limited

Keiichiro Mizuno

Kazuyoshi Iida

Kazutomo Murakami

Yoshikazu Kondo

Kazuo Kondo

Toshihiro Miyazaki

Masanori Murase

Masayasu Matsumoto

Sadao Nomoto

Noriaki Murayama

Kei Watanabe

Hirohumi Kikuchi

Katsumi Tashiro

Tomonori Katayama

Minoru Takahashi

Kenichi Onda

Naotaka Tomita

Noriharu Sato

Keiichiro Tabata

Akio Kinoshita

Tanetoshi Miura

Michiyuki Yamaguchi

Hareo Hamada

Nobuo Masaki

Yoji Suizu

Hirokazu Kudoh

An elastic wheel includes a disk () having a base rim (), a rim () for supporting a tire (), and an annular elastic rubber body () arranged between the outer peripheral surface of the base rim () and the inner peripheral surface of the rim (). A gap is formed between the elastic rubber body () and the outer peripheral surface of the base rim () or the inner peripheral surface of the rim (). The elastic rubber body () with the gap has a spring constant that shifts from a smaller value to a larger value as the input load increases, so that it absorbs vibration under small input conditions while being prevented from undergoing substantial deformation under large input conditions. The elastic wheel ensures riding comfortablesess performance and provides improved vibrationproof performance and soundproof performance, regardless of whether the input load is small or large, without sacrificing durability and safety. In terms of soundproof performance, provision of the gap is particularly effective in suppressing high-frequency noise of 100 Hz or higher.

Elastic wheel

An elastic wheel having a disk equipped with a base rim and a rim for supporting a tire includes a pair of guides fixed annularly on the inner peripheral surface of the rim and a pair of wall portions fixed annularly on the both side areas in the axial direction of the wheel on the outer peripheral surface of the base rim , where rubber elastic bodies are fitted annularly between the side surfaces of the guides and the side surfaces of the wall portions, respectively. The elastic bodies being installed are able to absorb vibrations by their shearing deformations, so that especially the riding comfortableness performance, the vibrationproof performance, and the soundproof performance can be improved against the small input load. Regarding the soundproof performance, furthermore, it is extremely effective on a high frequency area of 100 Hz or higher.

Acoustics or vibrations at a plurality of predetermined positions are respectively detected in the form of analog values, and the detected analog values are respectively converted into digital values. The digital values are subjected to digital filtering by using the digital values and filter factors, and at least one of the filter factors is changed such that the difference between the total sum of the results of digital filtering and a targeted value becomes minimum. The rate of contribution to an evaluation point is computed by using the results of digital filtering within a predetermined time when the difference becomes minimum, and the computed rate of contribution is displayed.

Method and apparatus for diagnosing sound source and sound vibration source

Disclosed is a vibration control method being largely effective in vibration-proof even when a natural frequency is relatively low and its transmissibility of vibration is high and being thus effective in reducing vibration in a wide range of frequencies; and its apparatus. In the above method, vibration information of a vibration source as a reference signal and vibration information of a vibration-proof object as an error signal are inputted into an adaptive filter. The reference signal is processed by regenerating a filter coefficient on the basis of adaptive algorithm, to form a feedforward signal. In the other hand, vibration information of the vibration-proof object is inputted in a feedback calculating means, and a feedback control signal is formed on the basis of a feedback control rule. The feedforward control signal and the feedback control signal are synthesized, to form a drive signal for a vibration exciting means. The vibration exciting means is thus controlled and driven on the basis of the drive signal.

Method and apparatus for controlling vibration

A method for electrically attenuating a noise in an area for a sound wave to be propagatable in a three dimensional direction by making up a drive signal from the information on the noise and previously given filter coefficients by use of an adaptive digital filter and then generating an additional sound wave in accordance with the drive signal for cancellation of the noise. In the electric noise attenuation method, there are provided in a given region for noise attenuation, first and second error sensor groups for detecting an interference sound wave produced between the noise and additional sound wave, at a sampling time, a filter coefficient is calculated based on the information relating to the first error sensor group, at the next sampling time, another filter coefficient is calculated based on the information relating to the second error sensor group, and these operations are repeatedly executed sequentially for each error sensor to thereby update the filter coefficient of the adaptive digital filter.

Electronic noise attenuation method and apparatus for use in effecting

A vibration isolating device comprises a base, a plurality of support members each placed onto the base and comprised of a two series layer of an electroviscous body and an elastomeric body, and a cradle supported through these support members. These support members are provided with circuit for applying voltage to each electroviscous body, respectively.

Vibration isolating support device

A vibration damping apparatus for transportation includes a vertical direction damping device having air springs and air dampers arranged in parallel on a base and horizontal direction damping device having laminated rubbers. The vertical and horizontal damping devices are combined in series for supporting a load base. The apparatus further includes an air supply source for supplying air into the air springs, control valves provided between the air springs and the air supply source for controlling air supply into and exhaust from the air springs, displacement detecting device for detecting displacements of the load base relative to the bases, and control device for controlling the control valves on the basis of results detected by the displacement detecting device to maintain the load base horizontally and at a constant level relative to the base whatever load is loaded on the load base.

Vibration damping apparatus for transportation

A vibration free container for transportation comprises vibration isolating device which are arranged under the container and comprises a lower layer and an upper layer. The lower layer consists of at least two long laminated rubber bodies in the form of a parallelepiped extending in parallel with each other and upper layer consists of a plurality of column-shaped vibration isolators fixed between a bottom plate of the container and upper surfaces of the laminated rubber bodies. Each of the laminated rubber bodies comprises rubber layers and metal plates alternately laminated. In another aspect the vibration free container comprises an outer casing and an inner casing received in the outer casing, and the vibration insulating device is interposed between the outer and inner casing to support the inner casing relative to the outer casing.

Vibration free container for transportation

A vibration absorbing apparatus for reducing vibrations of a vibration damping objective comprises a vibration member excited by a piezo-ceramic element. The voltage applied to the piezo-ceramic element is controlled in accordance with the vibration state of the objective.

Vibration absorbing apparatus

A vibration control system for damping vibration of an body to be isolated against vibration. The body is supported on a movable base through the medium of vibration-damping supporting structure. The control system comprises a vibration sensor for detecting vibration of the movable base. An inverse vibration signal generating circuit includes a digital sensor and in supplied with a detection signal outputted from the vibration sensor for generating a signal with a waveform to cancel out the vibration of the body through interference therewith. An actuator is connected operatively to the movable base and the inverse vibration signal generating circuit for converting the signal derived from the latter into a mechanical vibration to be applied to the body.

Vibration control system

An oscillating apparatus comprises a cylinder, a piston reciprocatingly movably fitted in the cylinder, shaft members connected to the piston and extending out of the cylinder. The cylinder, piston and shaft members form an oscillator. An inlet and an outlet for an electro-rheological fluid are provided at each of two cylinder chambers defined in said cylinder by the piston. The apparatus further comprises voltage applying devices for applying electric voltage to the electro-rheological fluid passing through the inlets and outlets, respectively, so that applications of the voltage to the inlet of one cylinder chamber and the outlet of the other cylinder chamber are simultaneously effected and applications of the voltage to the inlets of both the cylinder chambers are alternately effected. With this arrangement, the switching-over of the closing and opening of the inlets and outlets are very rapidly performed by the application and removal of the electric voltage so that the piston undergoes vibration which is transmitted through the shaft members to an object, structure or the like, with the result that the object is controllingly vibrated and vibration to which the object is subjected is effectively damped.

Oscillating apparatus for damping vibration

A vibration free container for transportation comprises vibration isolating device which are arranged under the container and comprises a lower layer and an upper layer. The lower layer consists of at least two long laminated rubber bodies in the form of a parallelepiped extending in parallel with each other and upper layer consists of a plurality of column-shaped vibration isolators fixed between a bottom plate of the container and upper surfaces of the lamianted rubber bodies. Each of the laminated rubber bodies comprises rubber layers and metal plates alternately laminated. In another aspect the vibration free container comprises an outer casing and an inner casing received in the outer casing, and the vibration insulating device is interposed between the outer and inner casing to support the inner casing relative to the outer casing.

A noise reducing apparatus is disclosed, comprising a lens-type hollow body consisting of a plurality of inclined hollow tubular passages. The lens-type hollow body has a plane incident surface and a curved emission surface and the length L.sub.2 of the hollow tubular passage is optimized in accordance with relevant dimensional parameters of setting of the lens-type hollow body in a sound field, to reduce noise from a spot sound source efficiently.

Noise reducing apparatus

Disclosed herein is an engine noise control device for use in automobiles or the like comprising a noise control member which is attached to an opening of an engine room of an automobile or the like. The noise control member has a plurality of hollow conduit passages penetrating from one of surfaces to the other surface thereof. The hollow conduit passages are so arranged that the length of the conduit passages becomes shorter from the central portion to the peripheral portion of the noise control member. Thereby, a noise-propagating direction is changed by controlling the noise to reduce the energy of sounds radiated and/or diffracted to the outside.

Engine noise control device for use in automobiles or the like

Disclosed herein is a sound wave control device which is shaped in a lens form or a prism form from an acoustically rigid porous material, wherein numerous paths having different path lengths are provided and the apparent medium density is varied. This second wave control device is used to improve the sound quality and the directivity of the sound waves from a speaker and the directional control of noises.

Growing community of inventors

Tokyo, Japan

Keiichiro Mizuno