Elevator device and noise reduction method in car

Abstract

The present invention provides an elevator apparatus and a method for reducing noise in a car. An object of the present invention is to simply and inexpensively provide a method for effectively and stably reducing noise in a car by suppressing standing acoustic waves generated in an elevator car, and a structure for realizing the same. The car is composed of six surfaces, namely a floor surface, a ceiling surface, a front surface, a back surface, and both side surfaces. When the shape of the ceiling viewed from the inside of the car is viewed as a substantially quadrilateral, it is installed near the center of each of the four sides constituting the quadrilateral. For the reference microphone, a second-order sound wave generating device is arranged in the center of the ceiling surface, and a second-order sound wave generating signal is generated based on the sound pressure signals collected by the plurality of reference microphones. The 2nd-order sound wave generation converts the signal into sound and transmits it.

Description

technical field [0001] The present invention relates to the technique of reducing the noise inside the car of an elevator device, in particular to the technique of suppressing the standing acoustic wave generated in the car at low frequency. Background technique [0002] With the development of high-rise building construction technology, high-speed elevators are also being sought. Recently, high-speed elevators with a speed of more than 1000m per minute have begun to appear. In these high-speed elevators, the car moves at high speed in the hoistway, but since the fluid noise generated by the separation of the flow of air increases in proportion to the sixth power of the speed, the noise inside the car becomes very Large, so that the comfort of the car significantly worse. In order to improve this, in a general high-speed elevator, a streamlined airtight chamber as shown in Patent Document 1 or a member called a spoiler is arranged above and below the car to suppress the sep...

AI Technical Summary

Problems solved by technology

[0011] As mentioned above, it is known that a standing acoustic wave is generated inside a box-shaped structure that does not absorb any sound, such as the elevator car. Even if the inner wall of the car vibrates slightly, the standing wave will be excited. In other words, it is difficult to reduce the noise only by adding the above-mentioned sealed chamber to reduce the sound source

As a countermeasure against such standing waves generated in the car, there is active noise control, but on the other hand, based on the reference The position and control method of the microphone are different, and there are also cases where the noise is not reduced smoothly but diverges and the noise increases

In addition, if the number of reference microphones is increased or the control method is complicated, the system necessary to achieve the goal becomes expensive, and the cost-effectiveness deteriorates

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