JPS63291778A - Soundproof construction of cabin of automobile and the like - Google Patents

Abstract

PURPOSE:To restrict the low-frequency sound or confined sound in a crew's cabin by providing a resonance room connected to the crew's cabin of an automobile or the like and arranging a sound absorbing material having a continuous, draft hole at least a part of the connecting part and/or the inner wall of the resonance room. CONSTITUTION:When this invention is applied to a passenger car 1, in order to use a laggage boot T as a resonance room 3, a partitioning plate separating a crew's cabin 2 from the laggage boot T is removed, and a sound absorbing material 5 having a continuous draft hole is installed instead. This sound absorbing material 5 is formed by laminating the foaming aluminum 6 over a sound absorbing material 7 of a urethane family, and the foaming aluminum 6 is installed so that it faces the crew's cabin 2. With this contrivance, the low-frequency sound or confined sound in the crew's cabin can be restricted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a soundproof structure for a vehicle interior of an automobile, and more particularly, to a soundproof structure capable of reducing so-called muffled sounds.

[Conventional technology]

BACKGROUND ART There are various types of noise in the passenger compartment of an automobile, such as the sound generated by the rotation of the engine and the sound generated during the process of transmitting power.

Therefore, various soundproofing measures have been taken in the past.

For example, in the three-box passenger car A shown in Fig. 8, a double wall structure is used for the partition wall a to separate the engine room E and cabin C, and the floor B is laminated with asphalt sheets, felt, and carpet. In addition, urethane and perforated PVC leather are laminated on the blind panel C of the partition from the trunk room T and on the ceiling d.

In addition, the two-box type passenger car B shown in Fig. 9 and the 1θ
Similar soundproofing measures have been taken for the one-box type passenger car shown in the figure.

[Problem that the invention seeks to solve]

In conventional automobiles, etc., soundproofing measures such as those mentioned above have been taken, but these soundproofing measures are ineffective at low frequencies (and have the problem of not being able to effectively suppress muffled sounds caused by low-frequency sounds). be.

Accordingly, an object of the present invention is to provide a soundproof structure for the cabin of a UJ vehicle, etc., which is capable of suppressing sounds in the low frequency range in particular and reducing muffled sounds.

[Means for solving problems]

The soundproof structure for a vehicle interior of a vehicle, etc. of the present invention includes a resonance chamber that communicates with a passenger compartment of the vehicle, and has continuous ventilation holes in the communication portion and/or at least a part of the inner wall of the resonance chamber. The structural feature is that a sound absorbing material is provided.

In the above configuration, the term "automobile" refers to a vehicle in general that has an engine and generates muffled noise in its passenger compartment. This includes not only automobiles such as passenger cars and trucks, but also construction machinery vehicles such as wheel loaders, cranes, and backhoes.

Also, it is preferable to provide the resonance chamber at a location far from the engine room, and its volume is 0.015r+? It is preferable to set it as above.

Further, it is preferable that the communication portion between the passenger compartment and the resonance chamber has a cross-sectional area of 0.01 m or more.

Further, it is preferable that the sound absorbing material is provided so as to partition the communication portion, or provided on the inner wall of the resonance chamber in a portion where the air particle velocity is high (sound pressure is low).

The sound absorbing material having continuous ventilation holes preferably has a sound absorption coefficient of 0.3 or more.

[Effect]

By making muffled noise generated in the passenger compartment due to transmission of vibrations from the engine and tires resonate in the resonance chamber communicating with the passenger compartment, the air particle velocity increases near the communication part and/or a specific inner wall of the resonance chamber. Therefore, a sound absorbing material with continuous ventilation holes that effectively converts the air particle velocity into heat energy is installed in this area, and the energy of the muffled sound generated in the passenger compartment is converted into heat. By converting it into energy, it attenuates and efficiently reduces muffled noise in the passenger compartment.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on embodiments shown in the drawings. Here, FIG. 1 is a schematic sectional view of an example of a passenger car implementing the soundproof structure of the present invention, FIG. 2 is a schematic sectional view of the sound absorbing material used in the example shown in FIG. Figure 4 is a diagram of pressure level measurement data, and Figure 4 is a diagram corresponding to Figure 1 on the other side of a passenger car equipped with the soundproof structure of the present invention. Figure 5 is a schematic diagram of an example of an industrial vehicle equipped with the soundproof structure of the present invention. The cross-sectional view, FIG.
The corresponding figures and FIGS. 7+al to 7+d+ are illustrative cross-sectional views of sound absorbing materials that can be used in the present invention, respectively.

Note that the present invention is not limited to the embodiments shown in the figures.

A passenger car 1 shown in FIG. 1 is a three-box type passenger car, and is basically the same as the passenger car A shown in FIG. The passenger compartment 2 is the same as the cabin C, and the partition wall a from the engine room E, the floorboards, and the ceiling d have the same soundproofing measures as the passenger car A.

However, in order to utilize the trunk room T as a resonance chamber 3, the partition plate C is removed and a sound absorbing material 5 having continuous ventilation holes is installed in its place.

Due to this sound absorbing material 5, the passenger compartment 2 and the resonance chamber 3 are apparently separated from each other, but since the sound absorbing material 5 has continuous ventilation holes, the two rooms 2 and 3 are in communication with each other in terms of musical conventions. crew room 2
The muffled sound generated in is guided to the resonance chamber 3 through the communication section 4.

As shown in FIG. 2, the sound absorbing material 5 is made by laminating foam aluminum 6 with a thickness of 15n+ and a urethane sound absorbing material with a thickness of 50 mm. will be installed.

Data obtained by measuring the sound pressure at the ear in the passenger compartment 2 of such a passenger car 1 are shown in FIG. 3 by a characteristic curve α (solid line). On the other hand, the characteristic curve β (broken line) shown in FIG. 3 is data obtained by setting the ear sound pressure level at 41 in the cabin C of the passenger car A shown in FIG. As you can understand by comparing these, for example, 9
A sound pressure level reduction effect of approximately 7 dB was obtained near 011z, which means that approximately 90% of the generated sound was reduced in terms of sound energy. In fact, human senses sensed that the muffled sound was significantly reduced.

Note that the sound absorbing material 5 also functions as a blindfold for the trunk room T.

FIG. 4 shows an example in which the present invention is implemented in a two-box type passenger car 11.

This passenger car 11 is similar to the passenger car B shown in FIG. 8, but the luggage compartment R is used as a resonance chamber 13, and a sound absorbing material 15 having continuous ventilation holes is provided on the surface S of the backrest of the rear seat on the side of the resonance chamber 13. is attached.

In this passenger car ¥L11, approximately 70% of the generated noise was reduced compared to passenger car B shown in FIG.

FIG. 5 shows an example in which the present invention is applied to a wheel loader 21. As shown in FIG.

A resonance chamber 23 is provided under the seat 26 of the driver's cab 22,
They are communicated with each other through a communication section 24 on the front side thereof, and are partitioned by a sound absorbing material 25 having continuous ventilation holes. Note that the resonance chamber 23 can also be used as a tool box.

FIG. 6 shows an example in which the present invention is implemented in a one-box type passenger car 31.

This passenger car 31 is similar to the passenger car shown in FIG. 10, but the luggage compartment R is used as a resonance chamber 33, and the sound-absorbing 1-hole having continuous ventilation holes is provided on the surface S of the backrest of the rear seat on the side of the resonance chamber 33. I am wearing 35.

A sound absorbing material 35' is also attached to the back door.

FIG. 7 (al to fd+ illustrate the structures of various sound absorbing materials that can be used in the present invention.

That is, FIG. 7 fa) is a sound absorbing material such as glass wool or rock wool. In these cases, reinforcing materials are required to maintain shape.

Further, FIG. 7 (bl) indicates a sound absorbing material such as a porous metal material such as foamed aluminum, sintered aluminum, porous casting, or a porous wood material formed by compressing wood chips.

Further, FIG. 7(C) shows a porous resin such as an aggregate of small diameter pipes or a honeycomb-shaped resin plate.

Further, FIG. 7fd) shows a sound absorbing material in which a sound absorbing material 41 such as glass wool or rock wool is accommodated in a casing 42 made of a perforated plate.

〔Effect of the invention〕

According to the present invention, a resonance chamber communicating with a passenger compartment of an automobile or the like is provided, and a sound absorbing material having continuous ventilation holes is disposed in the communication portion and/or at least a part of the inner wall of the resonance chamber. There is provided a soundproof structure for the cabin of a vehicle, etc., which can suppress low frequency sounds and muffled sounds in the passenger compartment.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of an example of a passenger car implementing the soundproof structure of the present invention, Fig. 2 is a schematic cross-sectional view of the sound absorbing material used in the example shown in Fig. 1, and Fig. 3 is a sound pressure level FIG. 4 is a diagram corresponding to FIG. 1 of another example of a passenger car equipped with the soundproof structure of the present invention, and FIG. 5 is a schematic cross-sectional view of an example of an industrial vehicle equipped with the soundproof structure of the present invention. , FIG. 6 is a view corresponding to FIG. 1 of still another example of a passenger car implementing the soundproof structure of the present invention, and FIG.
Figures fal to (d+ are illustrative cross-sectional views of sound-absorbing materials that can be used in the present invention, respectively, and Figure 8, Figure 9, and Figure 10 are cross-sectional views of main parts for explaining the conventional soundproof structure of automobiles. [Explanation of symbols] 1, 11.31...Passenger car 2.12...Crew compartment 3.13...Resonance chamber 4.14...Communication part 5.15...Has a continuous ventilation hole Sound absorbing material.

Claims (1)

[Scope of Claims] 1. A resonance chamber communicating with a passenger compartment of an automobile or the like is provided, and at least a portion of the communication portion and/or an inner wall of the resonance chamber is provided with:
A soundproof structure for a vehicle interior of an automobile, etc., characterized in that a sound absorbing material having continuous ventilation holes is provided. 2. A passenger compartment according to claim 1, which communicates the cabin and trunk of a three-box type passenger car, uses the trunk as a resonance chamber, and partitions the communication section with a sound absorbing material having continuous ventilation holes. Soundproof structure. 3. Claims that utilize the luggage compartment of a one-box type or two-box type passenger car as a resonance chamber, and at the same time, a sound absorbing material having continuous ventilation holes is attached to the part of the seat back facing the luggage compartment. The soundproof structure of the vehicle interior described in paragraph 1. 4. A soundproof structure for a vehicle interior of an automobile or the like according to any one of claims 1 to 3, wherein the resonance chamber has a volume of 0.015 m^2 or more. 5. A soundproof structure for a vehicle interior of an automobile or the like according to any one of claims 1 to 4, wherein the communication portion has a cross-sectional area of 0.01 m^2 or more. 6. A soundproof structure for a vehicle interior of an automobile or the like according to any one of claims 1 to 5, wherein the sound absorbing material having continuous ventilation holes has a sound absorption coefficient of 0.3 or more. 7. Claims 1 to 6, in which the sound absorbing material having continuous ventilation holes is mainly made of one selected from glass wool, rock wool, porous metal material, porous wood material, and porous resin. A soundproof structure for the interior of a vehicle, etc., as described in any one of the above.