JP2001001945A - Engine compartment structure for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce sound pressure over a wide frequency band, thereby improving acoustic characteristics in an engine compartment. SOLUTION: A front dash cover 28 consisting of a vertical wall 24 roughly perpendicular to a road surface and a top board 26 in roughly parallel with a hood are formed near the right and left corner of the rear part of an engine compartment E. In the vertical wall 24, a front end side 24a is disposed close to a strut housing 16, a rear end side 24b is disposed close to a dash panel 20, and a lower end side 24c is disposed close to a front side member 14. In the top board 26, a front end side 26a is disposed close to the strut housing 16, a rear end side 26b is disposed close to the dash panel 20, and a width- direction outside end side 26c is disposed close to a hood ridge 18, and the width-direction inside end side 26d of the top board 26 is connected to the upper end side 24d of the vertical part 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine room structure of a motor vehicle capable of improving radiation characteristics of engine noise entering a vehicle cabin.

[0002]

2. Description of the Related Art Conventionally, as a structure for improving the acoustic characteristics of an engine room of this kind of automobile, for example, Japanese Patent Laid-Open No. 10-324
As described in Japanese Patent Publication No. 267, a sound insulation wall having a plurality of partition walls formed continuously from a strut tower in an engine room to a dash panel is provided. That is, the sound insulation wall is joined to the hood ridge panel at one end, and is provided along the upper part of the front surface of the strut tower, and is joined to the other end of the first partition wall, along the upper part of the side part of the strut tower. And a front end is joined to a rear end of the second partition and a rear end of a side portion of the strut tower at a position outside the front side member in the vehicle width direction, and a lower end is formed on an upper surface of the front side member. A third partition wall, the rear end of which is joined to the dash panel at a position inward of the front side member in the vehicle width direction;
One end is joined to the rear end of the second partition along the dash panel, and the other end is constituted by a fourth partition joined to the hood ridge panel. This sound insulation wall is arranged closely or close to the lower surface of the hood via a weather strip, so that the space in the sound insulation wall is isolated from the space in the engine room and reduces the resonance mode in the engine front and rear direction in the engine room. Thereby, the acoustic characteristics in the engine room are improved.

[0003]

However, in the engine room structure of an automobile as described above, the sound pressure in the engine room can be reduced in some frequency bands, but increased in other frequency bands. Can be a problem. In addition, when the space between the upper end of the sound insulating wall and the hood is not completely adhered / insulated, the space in the sound insulating wall and the space in the engine room are not completely shut off, so that a sufficient effect cannot be obtained. . Further, in such a conventional structure, since the sound insulating wall is joined to surrounding members such as a front side member, for example, when there is a pipe that straddles the sound insulating wall such as a hose of an air conditioner, the structure of the sound insulating wall is changed. There is also the problem of complexity.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and the invention according to claims 1 to 8 can reduce the sound pressure over a wide frequency band and improve the acoustic characteristics of an engine room. It is an object of the present invention to provide an engine room structure of an automobile which can be manufactured by using the same.

Further, in addition to the above objects, the invention according to claim 4 provides an engine room structure of an automobile that can improve the acoustic characteristics of the engine room while facilitating the setting of parts such as piping. For that purpose.

[0006]

In order to achieve the above object, according to the present invention, a front end side is arranged near a strut housing and a rear end side is arranged near a dash panel in an engine room of an automobile. It is arranged, the lower end side is arranged close to the front side member, the vertical wall portion substantially perpendicular to the road surface, and the front end side is arranged close to the strut housing,
A rear end side is arranged close to the dash panel, a vehicle width direction outer side end is arranged close to the hood ridge, and a vehicle width direction inner side end is connected to an upper end side of the vertical wall portion, substantially parallel to the hood. And a top plate part.

According to a second aspect of the present invention, a space is formed between the top plate and the hood, which acts as a side branch for a sound having a frequency to be reduced.

[0008] The invention described in claim 3 is claim 1 or 2.
The left and right corners of the rear of the engine room formed between the strut housing and the dash panel are closed by the vertical wall portion and the top plate portion.

The invention described in claim 4 is the first to third aspects of the present invention.
Wherein at least a part of the lower end side of the vertical wall portion is higher than the upper surface of the front side member by a distance smaller than 1/4 of the distance between the lower surface of the hood and the upper surface of the front side member. Is arranged at the position of.

[0010] The invention according to claim 5 provides the invention according to claims 1 to 4.
Wherein at least a part of the top plate portion has a distance between the lower surface of the hood and the upper surface of the front side member.
The hood is disposed at a position lower than the lower surface of the hood by a distance smaller than / 4.

[0011] The invention according to claim 6 is the invention according to claims 1 to 5.
Wherein the cross-sectional area of the space formed between the top plate portion and the hood decreases toward the outside in the vehicle width direction.

The invention according to claim 7 is the invention according to claims 1 to 5
The cross-sectional area of the space formed between the top plate portion and the hood according to any of the above, increases as it goes outward in the vehicle width direction.

[0013] The invention according to claim 8 is the invention according to claims 1 to 7.
The vertical wall portion and the top plate portion according to any one of the above are configured as an integrated product that is continuously connected.

[0014]

According to the first aspect of the present invention, the sound field passes between the vertical wall portion and the hood by the vertical wall portion substantially perpendicular to the road surface and the top plate portion substantially parallel to the hood. It blocks the space in the engine room and the space enclosed between the vertical wall and the top panel, and the front and rear of the vehicle that has a node between the strut housing and the dash panel in the engine room. The direction resonance mode can be reduced more effectively.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the space between the top plate and the hood is provided with a space serving as a side branch for a sound having a frequency to be reduced. By doing so, in other words, assuming that the wavelength of the sound to be reduced is λ, the sound having the desired frequency can be reduced by setting the length of the space to be λ / 4.

According to the third aspect of the invention, in addition to the effects of the first or second aspect, the engine formed between the strut housing and the dash panel by the vertical wall portion and the top plate portion. By closing the rear left and right corners of the room, it is possible to reliably suppress the resonance mode that is conventionally excited between the rear corner of the engine room and the front of the engine room.

According to the invention described in claim 4, in addition to the effect according to any one of claims 1 to 3, the lower surface of the hood is provided between the lower end side of the vertical wall portion and the upper surface of the front side member. 1/4 of the distance from the top of the front side member
Since a gap can be provided if the distance is smaller, it is possible to easily set a component such as a pipe extending between components partitioned by the vertical wall portion.

According to the fifth aspect of the invention, in addition to the effect of any one of the first to fourth aspects, the distance between the top plate and the lower surface of the ceiling is increased by adjusting the distance between the lower surface of the hood and the front side member. By setting the distance smaller than 1/4 of the distance from the upper surface, a sufficient resonance mode reduction effect can be obtained, the function as a side branch can be maintained, and the sound pressure can be reduced over a wide frequency range. .

According to the invention described in claim 6, in addition to the effect according to any one of claims 1 to 5, the space acting as a side branch is obtained by changing the cross-sectional area toward the outside in the vehicle width direction. By changing the length, the function as a side branch can be exhibited for a plurality of frequencies, and the sound pressure can be reduced over a wide frequency band.

According to the seventh aspect of the invention, in addition to the effect of any one of the first to fifth aspects, the volume of the space acting as the side branch can be increased, and the resonance mode reducing effect can be maintained. Thus, the sound pressure reducing effect of the side branch can be increased.

According to the eighth aspect of the present invention, since the vertical wall portion and the top plate portion are formed as a continuous and integrated product, the upper edge of the vertical wall portion and the vehicle of the top plate portion are formed. The gap with the width direction inner side edge can be completely eliminated, and the leakage of sound waves from the gap can be prevented, and the number of parts can be reduced. Setting can be easily performed.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIGS. 1 and 2 are views showing a first embodiment of the present invention. FIG. 1 is a perspective view mainly showing a rear portion of the engine room E as viewed from the front, and FIG. 2 is a view taken along the line AA in FIG. Reference numeral 12 denotes an engine, in which an engine mount, other accessories, piping, and the like are omitted.

Front side members 14, 14 extending in the front-rear direction of the vehicle are disposed on both left and right sides of the engine room E, and a suspension is supported outside the front side members 14, 14 in the vehicle width direction. Are disposed, and further, hood ridges 18 are disposed on the outer side in the vehicle width direction. On the rear side of the engine room E, a dash panel 20 that partitions the engine room E from the vehicle interior is provided.
In FIG. 2, a wheel house 21 is joined to the front and rear ends of the strut housing 16.
Is Fender. The upper side of the engine room E is covered with a hood 22 (FIG. 2) so as to be freely opened and closed.

In the vicinity of the rear left and right corners of the engine room E, a dash front cover 28 including a vertical wall 24 substantially perpendicular to the road surface and a top plate 26 substantially parallel to the hood 22 is provided. Specifically, the vertical wall portion 24 has a front end side 24a.
Are disposed adjacent to the strut housing 16 and the rear end side 2
4b is disposed adjacent to the dash panel 20, and the lower side 24
c is arranged close to the front side member 14.
Further, the top plate 26 has a front end 26a disposed close to the strut housing 16, a rear end 26b disposed close to the dash panel 20, and a vehicle width direction outer side end 26c disposed close to the hood ridge 18. The inner edge 26d of the top plate 26 on the inner side in the vehicle width direction is the upper edge 2 of the vertical wall 24.
4d. The close arrangement may be completely bonded to each panel, may be overlapped on each panel, or may have a gap between each panel.

The vertical wall portion 24 and the top plate portion 26 can be composed of a metal panel, a resin, a non-woven fabric, or a piece of damper paper alone or in combination. Alternatively, it may be formed as an integrated product.

The vertical wall portion 24 and the top plate portion 26 cover the rear left and right corners of the engine room E formed between the strut housing 16 and the dash panel 20, and the space in the engine room E is provided. And a space 30 surrounded by the vertical wall portion 24 and the top plate portion 26,
The brake booster attached to the dash panel 20 and various accessories are covered. Further, as shown in FIG. 2, a space 3 is provided between the top plate 26 and the hood 22.
2 are formed. Further, in the present embodiment, the top plate 2
An elastic body 27 such as a weather strip is provided on the front end side 26a, the rear end side 26b and the outer side end 26c in the vehicle width direction.
And the elastic body 27 is brought into close contact with the strut housing 16, the dash panel 20, and the hood ridge 18.

Next, the operation of the first embodiment will be described.

With respect to the engine noise that enters the cabin, the noise radiated from the upper surface of the engine 12 is generated by the dash panel 20.
The contribution of the component transmitted through is high. Considering the transmission process from the upper surface of the engine 12 to the position of the occupant's ear, first, the noise radiated from the upper surface of the engine 12 is amplified by the acoustic characteristics of the engine room E and acts on the dash panel 20 as a load. Next, the vibration of the dash panel 20 excited by the sound pressure radiates noise into the vehicle interior, and as a result, generates sound pressure at the occupant's ear position. Therefore, as the level of the noise acting as a load on the dash panel 20 increases, the level of the noise reaching the ear position of the occupant increases. In order to reduce the noise that enters the cabin, the engine room E
It is important to minimize the rise in sound pressure level in the interior. In the present embodiment, the vertical wall portion 24 that is substantially perpendicular to the road surface can reduce the resonance mode in the vehicle front-rear direction that has a node between the strut housing 16 and the dash panel 20 of the engine room E. At this time, a top plate portion 26 connected to the upper end side 24d of the vertical wall portion 24 and substantially parallel to the hood 22 prevents sound waves from passing between the vertical wall portion 24 and the hood 22 and provides an engine room. E
The interior space and the space 30 surrounded by the vertical wall portion 24 and the top plate portion 26 are shut off, and the resonance mode is reliably reduced. Since the resonance mode is excited mainly in the upper space in the engine room E, the connection between the vertical wall portion 24 and the top plate portion 26 is reliably connected, and the resonance mode is effectively reduced. be able to. Vertical wall portion 24 or top plate portion 26
And strut housing 16, dash panel 20,
It is desirable to be as close as possible to the surrounding parts such as the front side member 14 or the hood ridge 18, but it is not necessarily limited to the case where they are joined.
Even if there is a gap between the vertical wall portion 24 or the top plate portion 26 and peripheral components, the resonance mode can be sufficiently reduced. Therefore, a slight gap between the vertical wall portion 24 or the top plate portion 26 and peripheral components such as the strut housing 16, the dash panel 20, the front side member 14, or the hood ridge 18 is allowed. 24
Alternatively, the setting of the top plate 26 can be easily performed, and retrofitting can be performed.

Since a space is formed between the top plate 26 and the hood 22, this space functions as a side branch which is a kind of resonance type silencer (so-called side branch), and the length of this space = λ Wavelength λ that satisfies / 4
The sound pressure can be reduced for the sound of. That is, in the case of the conventional structure, the sound pressure near the frequency corresponding to this λ may be increased due to the presence of the sound insulating wall. However, according to the present invention, the function as the side branch is additionally provided. Can be.

FIG. 3 is a graph showing acoustic characteristics to show the effect of the present embodiment. This figure shows the sound pressure level acting on the dash panel 20 due to the noise radiated from the upper surface of the engine 12 when no sound insulation wall exists between the strut housing 16 and the dash panel 20 (conventional example 1). Dash panel 2
In the case where a sound insulating wall as shown in Japanese Patent Application Laid-Open No. 10-324267 is provided (conventional example 2) in FIG. This indicates that the sound insulation characteristics are more excellent. Comparing this embodiment with Conventional Example 1, in this embodiment, the sound pressure at around 200 Hz is suppressed, but the sound pressure at around 300 Hz is suppressed. This is considered to be due to the fact that the resonance mode excited in the engine room E is reduced by the vertical wall portion 24 and the hood 22. In addition, comparing this embodiment with Conventional Example 2, although the sound pressure at around 300 Hz is slightly deteriorated in this embodiment, the sound pressure at around 200 Hz, which has a high sound pressure level in Conventional Example 2, is suppressed. It is considered that the space 32 formed between the top plate 26 and the top plate 26 functions as a side branch and exerts an effect of lowering sound pressure at such a frequency. Further, in the conventional example 2, unless the close contact / sound insulation between the upper end side of the sound insulation wall and the hood is maintained, the sound insulation wall, the space in the sound insulation wall, and the space in the engine room are not completely shut off, as shown in the graph of FIG. However, in the first embodiment, the upper end 24d of the vertical wall portion 24 and the inner end 26d in the vehicle width direction of the top plate portion 26 are connected to each other. And the space 30 surrounded by the vertical wall portion 24 and the top plate portion 26 can be shut off.

As a result, according to the first embodiment, the average sound pressure can be reduced in a wide frequency band, and the occupant's comfort can be improved.

(Second Embodiment) FIGS. 4 and 5 are views showing a second embodiment of the present invention. In the figure, the same members as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The dash front cover 28-1 is provided with a vertical wall portion 24-1 substantially perpendicular to the road surface and a top plate portion 26 substantially parallel to the hood 22.
The vertical wall portion 24-1 has a front end side 24a.
Are disposed adjacent to the strut housing 16 and the rear end side 2
4b is arranged close to the dash panel 20. The lower side 24c of the vertical wall portion 24-1 is the front side member 1
4 is disposed at a position above the upper surface 14a by a distance L1. This distance L1 is a distance L0 between the lower surface 22a of the hood 22 and the upper surface 14a of the front side member 14.
Is set to be smaller than 1/4. Then, the pipe 34 (FIG. 4) passes through a gap corresponding to the distance L1.
Is passing.

It is preferable that the distance L1 between the lower end side 24c of the vertical wall portion 24-1 and the upper surface 14a of the front side member 14 is small, but the distance L1 is smaller than １ ／ of the distance L0. With this, the same effect of reducing the resonance mode as in the case where there is no gap can be obtained. The vertical wall 2
It is not always necessary that the entire lower end side 24c of 4-1 has a gap smaller than 1/4 from the upper surface 14a of the front side member 14, and the main part thereof is larger than the upper surface 14a and 1/4 of the front side member 14. It is only necessary to have a small gap.

FIG. 6 is a graph showing the effect of the distance L1 on the acoustic characteristics. One vertical wall 2 of the left and right sides
Under the condition that the distance L1 of 4-1 is L1 = 0, the distance L1 of the other vertical wall portion 24-1 is L1 = 0, L0 / 40, L0.
In the case of / 4, the sound pressure level acting on the dash panel 20 for the noise radiated from the upper surface of the engine 12 is shown. When the gap is large, the effect of providing the vertical wall portion 24-1 and the top plate portion 26 is not obtained, and L1 =
In L0 / 4, the effect is almost the same as that of the conventional example 2. On the other hand, in L1 <L0 / 4, the sound pressure around 200 Hz is suppressed, and the sound pressure can be reduced over a wide frequency band. it can.

As described above, the lower edge 24c of the vertical wall portion 24-1 is formed.
Since a gap can be provided between the front wall member 14 and the upper surface 14a of the front side member 14, it is possible to easily set components such as pipes extending between components partitioned by the vertical wall portion 24-1.

(Third Embodiment) FIG. 7 is a view corresponding to FIG. 2 showing a third embodiment of the present invention. In the figure, the same members as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The dash front cover 28-2 includes a vertical wall portion 24 substantially perpendicular to the road surface and a top plate portion 26-1 substantially parallel to the hood 22.
The top plate 26-1 is disposed at a position lower than the lower surface 22a of the hood 22 by a distance L2. This distance L2 is set to be smaller than １ ／ of the distance L0 between the lower surface 22a of the hood 22 and the upper surface 14a of the front side member 14.

The top plate 26-1 and the lower surface 22a of the hood 22
If the distance L2 is too large, the effect of reducing the resonance mode in the longitudinal direction of the vehicle, which serves as a node between the strut housing 16 and the dash panel 20 in the engine room E, is reduced. If the gap is smaller than 1/4 of L0, a sufficient effect of reducing the resonance mode can be obtained. In addition, all of the top plate 26-1 is the hood 2.
It is not necessary to have a gap smaller than 1/4 from the lower surface 22a of the hood 22, and the main part thereof is
It is only necessary to have a gap smaller than / 4.

The graph of FIG. 8 shows the effect of the distance L2 on the acoustic characteristics, where L2 = 0, L0 / 10, L0 /
4, L0 / 3 indicate the sound pressure level acting on the dash panel 20 for the noise radiated from the upper surface of the engine 12, respectively. The gap increases (L2> L
0/4), the effect as a side branch of the space 32 is increased, and the increase in sound pressure around 200 Hz is suppressed, but it approaches the state without the dash front cover 28-2 (conventional example 1), and becomes 300 Hz. The effect in the vicinity disappears, and the effect does not change even if the gap is further increased. When L2 = 0, in other words, the top plate 26
If no space is formed between -1 and the hood 22, the effect as a side branch is reduced, and
The sound pressure around Hz rises. On the other hand, if L2 is 0 <
If L2 <L0 / 4, around 200Hz and 300H
The sound pressure near z can be suppressed, and the sound pressure can be reduced over a wide frequency band.

(Fourth Embodiment) FIGS. 9 and 10 show a fourth embodiment of the present invention. In the figure, the same members as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the fourth embodiment, the dash front cover 28-3 is composed of a vertical wall portion 24 substantially perpendicular to the road surface and a top plate portion 26-2 substantially parallel to the hood 22.
2, a front end side 26a is disposed close to the strut housing 16, a rear end side 26b is disposed close to the dash panel 20, and the vehicle width direction outer side end 26
c is disposed close to the hood ridge 18 and the top plate 2
The inner side edge 26d in the vehicle width direction of 6-2 is the vertical wall portion 24.
Is connected to the upper side 24d. And the top plate 26-
A step portion 26f is formed on the upper surface 26e of the second 2, and the cross-sectional area of the space 32-1 between the top plate portion 26-2 and the hood 22 decreases as going outward in the vehicle width direction.

In this embodiment, since there are a plurality of changing points of the cross-sectional area of the space 32-1, it is considered that the function as a side branch is exhibited for a wide frequency band. Sound pressure can be reduced.

(Fifth Embodiment) FIGS. 11 and 12 show a fifth embodiment of the present invention. In the figure, the same members as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the fifth embodiment, the front dash cover 28-4 is composed of a vertical wall portion 24 substantially perpendicular to the road surface and a top plate portion 26-3 substantially parallel to the hood 22.
3, a front end side 26a is arranged close to the strut housing 16, a rear end side 26b is arranged close to the dash panel 20, and a vehicle width direction outer side end 26
c is disposed close to the hood ridge 18 and the top plate 2
The inner side edge 26d in the vehicle width direction of 6-3 is the vertical wall portion 24.
Is connected to the upper side 24d. And the top plate 26-
The upper surface 26g of the third 3 is inclined, and the cross-sectional area of the space 32-3 between the top plate 26-3 and the hood 22 increases toward the outside in the vehicle width direction. In the illustrated example, the distance between the top plate 26-3 and the lower surface 22a of the hood 22 near the inner side 26d in the vehicle width direction of the top plate 26-3 (=
L3) is minimized, the cross-sectional area is minimized, and the distance gradually increases toward the outside in the vehicle width direction of the top panel 26-3, and when the distance reaches a certain distance (= L4). ,
The upper surface 26g of the top plate 26-3 is substantially parallel to the hood 22 again, and the cross-sectional area is constant.

In this embodiment, a sound pressure reduction effect can be obtained by increasing the volume of the space 32-2 serving as a side branch.

The graph in FIG. 13 shows the relationship between the distances L3 and L4 and the acoustic characteristics, where L4 / L3 =
1 and the engine 12 in the case of L4 / L3 = 1.6
The sound pressure level acting on the dash panel 20 for the noise radiated from the upper surface is shown. However, in each case, L3 = L0 / 8. By increasing L4, the effect as a side branch increases, and 3
It is possible to suppress a rise in sound pressure near 200 Hz while maintaining a reduction in sound pressure near 00 Hz.

[Brief description of the drawings]

FIG. 1 is a perspective view mainly showing a rear part of an engine room as viewed from the front, showing a first embodiment of the present invention.

FIG. 2 is an arrow view taken along the line AA of FIG. 1;

FIG. 3 is a graph of acoustic characteristics for representing an effect of the first embodiment.

FIG. 4 is a diagram corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 5 is a view as viewed in the direction of arrows along the line AA in FIG. 4;

FIG. 6 is a graph of acoustic characteristics for representing an effect of the second embodiment.

FIG. 7 is a diagram corresponding to FIG. 2, showing a third embodiment of the present invention.

FIG. 8 is a graph of acoustic characteristics for representing an effect of the third embodiment.

FIG. 9 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention.

FIG. 10 is a view as seen in the direction of arrows along the line AA in FIG. 9;

FIG. 11 is a view corresponding to FIG. 1 showing a fifth embodiment of the present invention.

FIG. 12 is an arrow view taken along line AA in FIG. 11;

FIG. 13 is a graph of acoustic characteristics for representing the effect of the fifth embodiment.

[Explanation of symbols]

E engine room 12 engine 14 front side member 14a upper surface 16 strut housing 18 hood ridge 20 dash panel 22 hood 22a lower surface 24, 24-1 vertical wall portion 24a front edge 24b rear edge 24c lower edge 24d upper edge 26d, 26-1 , 26-2, 26-3 Top plate 26a Front end 26b Rear end 26c Vehicle width direction outer side 26d Vehicle width direction inner side 26e Upper surface 26g Upper surface 30 Space surrounded by vertical wall and top plate 32, 32-1, 32-2 Space between the top plate and the hood

Claims (8)

[Claims] 1. A vehicle, which is substantially perpendicular to a road surface, has a front end located close to a strut housing, a rear end located close to a dash panel, and a lower end located close to a front side member in an engine room of a vehicle. A vertical wall portion, a front end side is arranged close to the strut housing, a rear end side is arranged close to the dash panel, a vehicle width direction outside side end is arranged close to the hood ridge, and a vehicle width direction inside side end is An engine room structure for an automobile, comprising: a top plate portion connected to an upper end side of a vertical wall portion and substantially parallel to a hood. 2. The engine room structure of an automobile according to claim 1, wherein a space that acts as a side branch for a sound having a frequency to be reduced is formed between the top plate and the hood. 3. By the vertical wall portion and the top plate portion,
3. The engine room structure of an automobile according to claim 1, wherein left and right corners of a rear portion of an engine room formed between the strut housing and the dash panel are closed. 4. A method according to claim 1, wherein at least a part of a lower side of the vertical wall is higher than the upper surface of the front side member by a distance smaller than １ ／ of a distance between a lower surface of the hood and an upper surface of the front side member. The engine room structure of an automobile according to any one of claims 1 to 3, wherein the engine room is disposed at a position. 5. The apparatus according to claim 1, wherein at least a part of the top plate is a quarter of a distance between a lower surface of the hood and an upper surface of the front side member.
The engine room structure of an automobile according to any one of claims 1 to 4, wherein the engine hood is disposed at a position lower than a lower surface of the hood by a smaller distance. 6. The vehicle according to claim 1, wherein a cross-sectional area of a space formed between the top plate and the hood decreases as it goes outward in a vehicle width direction.
The engine room structure of the automobile according to the paragraph. 7. The vehicle according to claim 1, wherein a cross-sectional area of a space formed between the top plate and the hood increases as it goes outward in the vehicle width direction.
The engine room structure of the automobile according to the paragraph. 8. The apparatus according to claim 1, wherein said vertical wall portion and said top plate portion are formed as a continuous and integrated product.
The engine room structure of an automobile according to any one of claims 7 to 9.