JPH1178981A - Sound insulating structure between cabin and engine compartment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the rigidity and vibration damping characteristics of a cowl and dash panel by overlappingly installing the upper part of a dash panel fixed to a box-shaped cowl openably on the front surface of the cowl and openably installing a highly damping adhesive material in a space between the dash panel and the cowl. SOLUTION: A cowl 3 having a frame-shaped cross section is disposed on the upper side of a dash panel 2 which partitions an engine compartment 10 from a cabin 11 adjacently to a hood 4 and a windshield 8. Also brackets 13 and 14 for supporting a steering column 15 are fixed to the cowl 3, and an instrument panel 12 is connected to it. In this case, the upper side of the dash panel 2 is extended to the hood 4 side so as to arrange it overlappingly with the front surface of the cowl 3. Then an area equivalent to the overall overlapped area is disposed at a specified gap from the cowl 3, and a high damping adhesive material mixed favorably with rubber material is provided in the gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproof structure between a vehicle room and an engine room, which is suitable for reducing a muffled sound in a vehicle room mainly due to sound waves generated from attached devices such as an engine and an air cleaner.

[0002]

2. Description of the Related Art FIG. 4 shows an outline of a structure around an engine in a general vehicle. The engine 6 having the air cleaner 7 and the like is shielded on the front side by the grill 5 and the like, provided with the dash panel 2 on the rear side, and covered by the hood 4 on the upper side. That is, the engine 6 and the like are surrounded by these, and the engine room 10 is formed. The lower side of the engine room 10 is opened. Also,
A floor panel 9 is connected to a lower end of the dash panel 2.

A box-shaped cowl 3 is arranged above the dash panel 2. Cowl 3 is cowl outer panel 3
a and a cowl inner panel 3b, and has a frame-like cross section. The cowl outer panel 3a and the cowl inner panel 3b are flanged at the lower end on the engine room 10 side and fixed by spot welding or the like to fix the flange 3c.
To form The dash panel 2 has its upper edge flange 2a fixed to the flange 3c of the cowl 3 by spot welding or the like. A hood 4 and a windshield 8 are arranged close to the cowl 3, respectively.

In the above-described vehicle structure around the engine 6, the engine room 10 and the vehicle room 11 are partitioned via the dash panel 2 and the cowl 3. Therefore, sound waves generated from the engine 6 and the air cleaner 7 hit the dash panel 2 and the cowl 3 and vibrate them. Vibration waves due to these vibrations are transmitted into the passenger compartment 11 and generate a so-called muffled sound. It is required to reduce the muffled sound due to unpleasant sound. For this purpose, a dash panel 2 having a double structure or a means for improving the rigidity of the cowl 3 can be considered, but this increases the weight and the cost. I was

[0005] On the other hand, as a known means for reducing the muffled sound and the like, for example, JP-A-5-189596 and JP-A-4-349051 can be mentioned. JP-A-5-18
No. 5956, the “body structure” is such that the upper end of the rain force fixed to the vehicle compartment side of the dash lower panel which is flanged toward the lower surface of the cowl box with a vibration damping member interposed is extended to the lower surface of the cowl box, A space is formed at the joint, and the space is filled with a structural adhesive (filler). By filling the space with this structural adhesive, the sealing of the joint between the cowl box and the dash lower panel is completed, and these vibrations are suppressed to improve the vibration damping performance and sound insulation performance. It was made.

On the other hand, Japanese Patent Laid-Open Publication No. Hei 4-349051 discloses a "sound-absorbing material mounting structure" in which a cowl-side sound absorbing material integrally formed with a dash sound absorbing material attached to an engine room side of a dash panel is provided. A sound insulating space is formed between the inner surface of the cowl-side sound absorbing material and the cowl box, and the upper end of the cowl-side sound absorbing material is connected and fixed to the hood panel side. By forming this sound insulation space, the sound pressure from the engine room side is reduced, and the intrusion of noise into the vehicle interior is reduced.

[0007]

Problems to be Solved by the Invention Japanese Patent Application Laid-Open No. 5-18595
No. 6 discloses a sound insulating effect as described above, but does not improve the rigidity of the cowl and the dash panel as in the present invention. I do not have. Therefore, the effect of reducing the muffled noise in the passenger compartment is lower than in the present invention.
Further, the present invention is characterized by the structure of the joint portion between the cowl and the dash panel, and is different from the present invention in configuration. On the other hand, JP-A-4-3490
The technology disclosed in Japanese Patent Publication No. 51 does not improve the rigidity of the cowl box and the rigidity of the dash panel itself. The technology differs greatly from the present invention in the configuration, and the muffled sound in the vehicle compartment is similar to the above-described known technology. The effect of reducing is small.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and the known art. The cowl and the dash panel are formed by relatively simple means for devising the structure at the joint between the cowl and the dash panel fixed thereto. It is an object of the present invention to provide a soundproof structure between a vehicle compartment and an engine room, which improves the rigidity and vibration damping characteristics of the vehicle and reduces vibration caused by sound waves from the engine side to reduce the muffled sound in the vehicle room. .

[0009]

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention provides a box-shaped cowl formed below a windshield and sandwiched between front pillars. A dash panel having an upper portion fixed thereto and arranged behind the engine and having a lower end connected to the floor panel, and a hood or the like covering the engine, for generating sound waves generated in an engine room formed around the engine in a cabin side. Soundproof structure to reduce transmission to the
The dash panel has an upper portion overlapped with the front surface of the cowl, and is disposed in the space between the overlapped dash panel and the cowl with a high damping adhesive. And a soundproof structure between the engine room. More specifically, the high damping adhesive is formed by mixing a rubber material into an epoxy resin. Further, the ratio of the actual overlap area of the dash panel to the entire area where the dash panel can overlap the cowl is at least 50% or more.

A dash panel is arranged on the front face of the box-shaped cowl so as to overlap, and a high-damping adhesive is provided in a gap between the two, and the two are integrally formed via the adhesive. Fixed. Therefore, the rigidity and vibration damping characteristics of the cowl and the dash panel are improved, and the vibration of the cowl and the dash panel due to sound waves from the engine side is reduced.
As a result, the muffled sound in the vehicle interior can be reduced. In addition, by using an epoxy resin mixed with a rubber material as an adhesive, the damping effect can be improved, and the bonding strength between the two can be improved. In addition, it is desirable that the area of the overlap portion between the cowl and the dash panel is large, but in some cases, the entire area cannot be used in relation to the members attached to the cowl, but in order to surely increase the effect of the present invention. The cowl and the dash panel have at least 5
It is desirable to overlap by 0% or more and to interpose an adhesive in that portion.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, an engine room 10 for housing an engine 6 having an air cleaner 7 and the like.
And the cabin 11 are partitioned via the dash panel 2.
The engine room 10 is formed by being surrounded by the grill 5, the dash panel 2 and the hood 4, and its lower side is opened. On the other hand, the vehicle interior 11 has a dash panel 2 and a windshield 8 arranged on the front side, and a roof panel (not shown) upward,
It consists of a space in which a back panel (not shown) is arranged on the rear surface and a floor panel 9 is arranged on the lower surface.

A cowl 3 is arranged above the dash panel 2. Cowl 3 is hood 4 and windshield 8
And is sandwiched between front cowls (not shown) arranged on both sides of the cowl 3. The cowl 3 has a frame-shaped cross section in which the periphery is surrounded by a cowl panel to form a space inside. Also, as shown in FIG.
Brackets 13 and 14 for supporting a steering column 15 are fixed to the cowl 3, and an instrument panel 12 is connected thereto. A floor panel 9 is connected to a lower end of the dash panel 2.

As shown in FIGS. 1 and 2, the dash panel 2 of the present invention has an upper side extending to the hood 4 side and an upper side overlapping with the front surface of the cowl 3. That is, as shown in FIGS. 2 and 3, the dash panel 2 is arranged so as to overlap the front surface of the cowl 3 by an area of a × b. Note that, for convenience of explanation, the area of the overlap of a × b is temporarily referred to as the entire area of the overlap.

As shown in FIG. 2, a portion corresponding to the entire area of the overlap of the dash panel 2 is not fixed to the cowl 3 as it is, but is arranged at a distance δ (FIG. 2). In this gap δ, a high damping adhesive 1 is interposed. That is, the dash panel 2 and the front surface of the cowl 3 are fixed via the adhesive 1.

The material of the adhesive 1 interposed between the dash panel 2 and the cowl 3 is not particularly limited as long as it has a high damping property, but it has good handleability and has adhesiveness. As a material having a function, for example, a material obtained by mixing a rubber material with an epoxy resin is used. This mixing ratio is not specified, and the dash panel 2 and the cowl 3
It is set as appropriate in consideration of the structure and rigidity. By interposing the adhesive 1 described above, the upper portion of the dash panel 2 and the front surface of the cowl 3 are actually integrally fixed. Therefore, the rigidity of both members is improved, and the vibration applied to the dash panel 2 and the cowl 3 is attenuated by the damping property of the adhesive 1.

It is desirable that the entire area of the overlap having an area of a × b functions as an area where the adhesive 1 is provided. However, a cutout portion to which a wiper motor and clamps are attached is required in the entire area of the overlap. That is, as schematically shown in FIG. 3, A ₁ , A ₂ ,
Portion indicated by A ₃ is used as the notch. Therefore, the dash panel 2 and the cowl 3 overlap only by the area of a × b− (A ₁ + A ₂ + A ₃ ). If the area that actually overlaps is small, the degree of improvement in the rigidity of the dash panel 2 and the cowl 3 is reduced, and the damping property is also reduced. Therefore, in the present invention, it is desirable that the area that actually overlaps is kept at least 50% or more of the total area (a × b) of the overlap. This is because 50% or more has been proved to achieve the desired effects of the present invention.

As will be apparent from the above description, the present invention makes the dash panel 2 and the cowl 3 overlap with each other, and the adhesive sound is provided at the overlap portion to make the booming sound in the vehicle interior very simple. Can be significantly reduced.

[0018]

【The invention's effect】

1) According to the soundproof structure between the cabin and the engine room according to the first aspect of the present invention, the dash panel and the cowl are overlapped and joined, and a high-damping adhesive material is interposed at the overlap portion. As a result, the stiffness and vibration damping characteristics of the dash panel and the cowl are improved, vibration due to sound waves from the engine side is suppressed, and the effect of reducing the muffled sound in the vehicle interior is enhanced. 2) According to the soundproof structure between the vehicle compartment and the engine room according to the second aspect of the present invention, since a high-damping adhesive material mixed with an epoxy resin and a rubber material is used, The improvement and the high damping property are surely performed. 3) According to the soundproof structure between the cabin and the engine room according to claim 3 of the present invention, the predetermined effect can be obtained if the actual overlap area between the dash panel and the cowl is 50% or more. Notches necessary for attaching a member such as a wiper motor to a cowl or a dash panel can be provided as they are, and can be easily implemented without requiring a special design change or the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an outline of a vehicle structure around an engine having a soundproof structure of the present invention.

FIG. 2 is a partial cross-sectional view showing an enlarged portion of an overlap between a cowl and a dash panel, which is a main part of the present invention.

FIG. 3 is a schematic plan view for explaining an actual overlapping state between a cowl and a dash panel in the present invention.

FIG. 4 is a sectional view showing an outline of a conventional vehicle structure around an engine.

[Explanation of symbols]

 Reference Signs List 1 adhesive 2 dash panel 3 cowl 4 hood 5 grill 6 engine 7 air cleaner 8 windshield 9 floor panel 10 engine room 11 cabin 12 instrument panel 13 bracket 14 bracket 15 steering column

Claims (3)

[Claims] 1. A box-shaped cowl formed below a windshield and sandwiched between front pillars, an upper portion is fixed to the cowl, the cowl is arranged behind an engine, and a lower end is a floor panel. And a dash panel connected to the engine and a hood or the like covering the engine to reduce the transmission of sound waves generated in an engine room formed around the engine to the passenger compartment side, wherein the dash panel is A vehicle body, wherein an upper portion is disposed so as to overlap a front surface of the cowl, and a high damping adhesive is provided in a gap between the overlapped dash panel and the cowl. Soundproof structure between the engine room. 2. The soundproof structure between a vehicle room and an engine room according to claim 1, wherein the high-damping adhesive is made of epoxy resin mixed with a rubber material. 3. The cabin according to claim 1, wherein a ratio of an actual overlapping area between the dash panel and the cowl is at least 50% of a total area where the dash panel can overlap the cowl. Soundproof structure between engine rooms.