Automotive floor panel structure

Abstract

The present invention is a floor panel structure of a car body where an automobile floor comprises a floor panel that is connected to the frame members of the car body and also has a vibration mode adjusting structure that suppresses the generation of acoustic emission by generating 2x1 mode vibration in a predetermined frequency band. The floor panel has a non-rectangular vibration region and the vibration mode adjusting structure of the floor panels the vibration mode adjusting structure of the floor panel comprises a vibration adjusting part that defines the vibration distribution and vibration amplitude of the antinodes of 2x 1 mode vibration, and the vibration adjusting part is disposed within the a non-rectangular vibration region so as to make the vibration volumes of two antinodes of vibration in 2x1 mode nearly the same.

Description

technical field [0001] The present invention relates to a floor panel structure of a vehicle body, and more particularly, to a floor panel structure of a vehicle body, wherein the floor includes a floor panel connected to a frame element of the vehicle body. Background technique [0002] It is well known that vibrations are transmitted from the frame connected to the engine or the suspension to the floor panel, causing the floor panel to vibrate. As a result, the air in the passenger compartment vibrates violently, resulting in unpleasant vibration and noise in the cabin. [0003] At this time, the vibration source that causes the above problem may be the vibration of the engine itself or the road noise transmitted from the suspension, and this road noise usually includes the component generated by the resonance in the tire and the component generated by the suspension resonance. [0004] Common measures taken to suppress such vibration and noise include the use of vibration...

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Problems solved by technology

[0008] However, as described above, in the conventional case where the vibration-damping material and the vibration-proof material are fixed on the entire surface of the floor panel, there are problems of increased material cost and increased vehicle weight.

In addition, if the thickness of the floor panels increases, there is also the problem of increased vehicle weight.

[0009] In addition, with the floor panel structure described in the above-mentioned Japanese Patent Unexamined Publication, for example, in order to generate vibration in the 2×1 mode, the vibration region of the floor panel must have an approximately 2×1 rectangular shape, but since parts are placed Under the vehicle floor including drive shafts, differentials and other drive train components, suspension and other suspension system components, exhaust pipes, mufflers and other exhaust system components, and fuel tanks, and also because of the distance between seats in the passenger compartment In relation to each other, the layout of the frame elements is limited, so that the floor panel connected to the frame elements cannot be in a roughly 2×1 rectangular shape, and therefore there is a problem that it is impossible to create Vibration in ×1 mode

[0010] On the other hand, when the vibration area of ​​the floor panel is not approximately 2×1 rectangular shape, it is conceivable to form a rectangular vibration area by means of high rigidity bead or the like to form a 2×1 vibration area, but if the plate of the floor panel If the stiffness of the parts is very high or the vibration area is narrow, the original resonance frequency of the floor panel itself is very high. If this bead is set on such a floor panel, the stiffness of the floor panel will be greatly improved, and the resonance frequency will be lower. It is further increased, so that the vibration of the 2×1 mode is generated in a frequency band higher than 250Hz, so there is a problem that it is impossible to generate a 2×1 mode in a frequency of 250Hz close to the road noise generated by resonance in the tire

[0011] In addition, even if the 2×1 mode vibration is generated in a vibration region that is not a 2×1 rectangular shape, since the amplitude and distribution of the two vibration antinodes in the 2×1 mode are different, the respective vibrations of the two vibration antinodes There is a difference between the vibration volumes and there is a problem that the mutual canceling effect of the sound waves of each vibration antinode becomes weak

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