KR-102962259-B1 - DEVICE FOR REDUCING VIBRATIE

KR102962259B1KR 102962259 B1KR102962259 B1KR 102962259B1KR-102962259-B1

Abstract

A vibration reduction device is disclosed. A vibration reduction device according to one embodiment of the present invention is a vibration reduction device attached to a structure to block transmitted sound transmitted through said structure, wherein a plurality of unit cells made of acoustic metamaterial and having different target frequencies are connected via a first bridge to form a unit structure having a target frequency band, and wherein a set number of said unit structures are connected and attached via a second bridge according to the type of said structure, said unit structure comprises a mass part whose size is set according to the target frequency, a base frame formed in the shape of a rectangular frame in which the mass part is eccentrically disposed therein, and a support part connecting the mass part and the base frame and whose size is set according to the target frequency.

Inventors

장경진
홍상진
박동철

Assignees

현대자동차 주식회사
기아 주식회사

Dates

Publication Date: 20260507
Application Date: 20210316

Claims (11)

A vibration reduction device attached to a structure to block transmitted sound transmitted through the structure, A plurality of unit cells made of acoustic metamaterial and having different target frequencies are connected through a first bridge to form a unit structure having a target frequency band, and depending on the type of the structure, a set number of unit structures are connected and attached through a second bridge, The above unit cell is, A mass part whose size is set according to the target frequency; A base frame formed in the shape of a square frame, wherein the mass portion is eccentrically disposed therein; and It includes a support member that connects the above-mentioned mass part and base frame, and whose size is set according to the target frequency; A vibration reduction device in which a variable groove is formed in the central part of the connecting part of the above support member, and the size of the variable groove is changed according to the target frequency to adjust the overall length.
In paragraph 1, The above mass part A vibration reduction device formed in the shape of a square block.
In paragraph 2, The above mass part A vibration reduction device that increases the amount of vibration reduction by being set so that its magnitude increases as the above target frequency decreases.
In paragraph 1, The above mass part A vibration reduction device positioned at a certain height above the upper surface of the base frame.
In paragraph 1, The above mass part A vibration reduction device including an engraving section for numbering on the upper surface.
In paragraph 1, The above support A vibration reduction device that connects the mass part and the base frame, and is positioned in a direction facing inward, respectively, in each unit cell forming the unit structure.
In paragraph 1, The above support A vibration reduction device that is fixed to one side of the upper surface of the base frame through a first protruding fixing part, has a connecting part integrally extended at a position spaced a certain height from the first fixing part, and is connected to the center of one side of the mass part through a second fixing part at the other end that is integrally formed with the connecting part.
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In paragraph 1, The above first bridge is A vibration reduction device formed in the shape of a hemispherical ring and connected in multiple numbers between each base frame of the unit cell forming the unit structure.
In paragraph 1, The above second bridge is A vibration reduction device formed in the shape of a hemispherical ring, connecting one set base frame among the base frames of each unit cell forming a single unit structure and one set base frame of an adjacent unit structure.
In paragraph 1, A vibration reduction device attached to the structure, wherein an adhesive member is formed on the lower surface of the base frame.

Description

Vibration Reduction Device {DEVICE FOR REDUCING VIBRATIE} The present invention relates to a vibration reduction device, and more specifically, to a vibration reduction device capable of efficiently reducing vibration and noise transmitted through a structure. Vehicle weight reduction and increased engine power resulting from fuel efficiency reduction and power output improvement—essential challenges in the industry—are making development in terms of noise and vibration even more difficult. Accordingly, there is an even more urgent need for structural improvements that can robustly enhance the vehicle's NVH (Noise Vibration Harshness) performance. Meanwhile, a dash panel is located between the vehicle's engine compartment and the driver's seat, and a floor panel forming the interior floor surface is located from the lower end of the dash panel toward the rear of the vehicle body. When accelerating in a vehicle, structural noise transmitted through the dashboard panel acts as a very important issue for improving the vehicle's NVH performance. In conventional technology, to improve this, methods are applied to reduce and block noise transmitted from the engine room and road noise transmitted from the ground by increasing the thickness of the dash panel, increasing the curved surface, or adding reinforcing members or vibration dampers. However, while the aforementioned method of reducing vehicle body vibration is effective for noise reduction, it entails many limitations, such as increased manufacturing costs and vehicle weight. Therefore, a new method is required to reduce noise entering the vehicle's interior from the exterior or the engine compartment. The matters described in this background technology section are written to enhance understanding of the background of the invention and may include matters that are not prior art already known to those skilled in the art to which this technology belongs. FIG. 1 is a schematic diagram showing a vibration reduction device according to an embodiment of the present invention. FIG. 2 is a perspective view of a unit structure applied to a vibration reduction device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of a unit cell applied to a vibration reduction device according to an embodiment of the present invention. Figure 4 is a graph showing the dispersion relationship between the wavenumber vector and frequency of a vibration reduction device according to an embodiment of the present invention. FIG. 5 is a graph showing the vibration response of a vibration reduction device according to an embodiment of the present invention measured by an accelerometer. Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. To clearly explain the present invention, parts unrelated to the description have been omitted, and throughout the specification, identical or similar components are described using the same reference numerals. In addition, the classification of the names of the components in the following description as "1st," "2nd," etc., is intended to distinguish them because their names are identical, and is not necessarily limited to that order. The vibration reduction device according to an embodiment of the present invention is intended to reduce noise transmitted through structures in various industrial fields, such as automobiles, aircraft, home appliances, and mechanical structures. In other words, noise generated from engines or motors in automobiles, aircraft, home appliances, and mechanical structures is transmitted through the air or through the structures. Accordingly, the vibration reduction device according to an embodiment of the present invention can be applied to a structure to reduce noise transmitted through the structure. For example, the above structure may be an internal panel or support for electronic products such as a washing machine, refrigerator, dishwasher, microwave, air conditioner, or heater. In addition, the above structure may be a support or reinforcing material that supports a sound barrier of a road or a rainwater drainage pipe of a building, and may also be a device that performs milling, cutting, extrusion, and forming. In addition, the above structure may be a support or housing for rotating equipment such as pumps, compressors, and turbines of a power plant, and may also be a support for a computer hard disk. In particular, the structure applied in the automotive industry can be a roof panel as part of the vehicle body, or a top panel positioned on the upper side of the engine room cowl. In addition, it can be applied not only to the parts of the vehicle body where vibration and noise are transmitted, but also to all devices where