JPH07149262A - Dash panel structure - Google Patents

Abstract

PURPOSE:To reduce a vibrational noise without increasing weight of a dash panel. CONSTITUTION:In a dash panel 16 to partition an engine room 12 and the interior 14, a car width directional left half is formed as a corrugated left side curved structure 16A which has a projecting part 26 swelling to the engine room 12 side and runs in the car width direction with the car width directional center line 24 as a boundary. A car width directional right half part of the dash panel 16 is also formed as a corrugated side curved structure 16B which has a projecting part 28 swelling to the interior 14 side and is put in an almost reverse phase to the left side curved structure 16A in the car width direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dash panel structure for partitioning an engine room and a vehicle compartment of a vehicle such as an automobile.

[0002]

2. Description of the Related Art Conventionally, a vehicle such as an automobile is provided with a dash panel for partitioning an engine room and a vehicle compartment, and an example of this dash panel is shown in Japanese Utility Model Laid-Open No. 59-1267.
No. 76 publication.

As shown in FIG. 6, in order to reduce vibration noise, various components such as a central surface portion 70A facing the rear portion of the engine and a side surface portion 70B facing the air conditioner mounting portion are attached in principle to the dash panel 70. The dash panel surface of the non-existing portion is formed on the curved forming portion 72 such as a curved surface or a spherical surface, and these curved forming portions 72 are
A plurality of vertical beads 74 are formed, and the upper ends of these vertical beads 74 are connected to a joint between a cowl outer panel and a cowl inner panel (not shown).

[0004]

However, in this dash panel structure, the dash panel 70 is formed with the curved forming portion 72 and the vertical bead 74, whereby the rigidity of the dash panel 70 is improved and the dash panel 70 is improved.
To suppress the vibration of the dash panel 7
By forming the vertical beads 74 at 0, the total area of the dash panel 70 increases and the weight increases, which leads to an increase in the weight of the vehicle body.

In view of the above facts, it is an object of the present invention to provide a dash panel structure capable of reducing vibration noise without increasing the weight of the dash panel.

[0006]

According to the dash panel structure of the present invention, in a dash panel arranged between an engine room and a vehicle compartment of a vehicle, the dash panel is formed in the left half of the dash panel in the vehicle width direction. And a right-side curved structure formed in the right half of the dash panel in the vehicle width direction and formed in a right half in the vehicle width direction of the dash panel and having a wavy shape substantially in antiphase with the left-side curved structure. It is characterized by that.

[0007]

In the structure of the dash panel of the present invention, the vibration of a frequency of 180 Hz or less is generated by the force in the substantially vehicle width direction input from the rear end portions of the front side members connected to the vehicle width direction both end regions of the dash panel. In mode,
When both ends of the dash panel in the vehicle width direction move to the front of the vehicle, when the center of the dash panel in the vehicle width direction moves to the rear of the vehicle and when both ends of the dash panel in the vehicle width direction move to the rear of the vehicle , The center of the dash panel in the vehicle width direction moves to the front of the vehicle body and sounds.

In this case, in the dash panel structure of the present invention, the left-side curved structure formed in the left half of the dash panel in the vehicle width direction and the right-side curved structure formed in the right half of the dash panel in the vehicle width direction are substantially mutually. Since it is wavy with the opposite phase, the phase of the acoustic mode on the left side of the dash panel is
180 degrees out of phase with the acoustic mode on the right side of the dash panel and cancel each other out to reduce vibration noise.

Therefore, unlike the conventional structure, it is not necessary to form a bead on the dash panel, so that vibration noise can be reduced without increasing the weight of the dash panel.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the dash panel structure of the present invention will be described with reference to FIGS.

In the figure, an arrow FR indicates the front direction of the vehicle body, an arrow IN indicates a vehicle width inner direction, and an arrow UP indicates the vehicle body upward direction.

As shown in FIG. 2, the vehicle body 10 is provided with a dash panel 16 for partitioning an engine room 12 and a vehicle room 14. Rear ends 20A of the pair of front side members 20 are welded to both end regions of the dash panel 16 in the vehicle width direction.

The front side members 20 have a closed cross-section structure extending in the front-rear direction of the vehicle body, and have front subframes (not shown) attached thereto. In addition, a tunnel portion 22 is formed at the lower center of the dash panel 16 in the vehicle width direction. This tunnel section 22
The shape viewed from the front is a trapezoidal shape with an open bottom, and is connected to a tunnel portion of a floor panel (not shown).

As shown in FIGS. 1A and 1B, in the dash panel 16, the left half in the vehicle width direction bulges toward the engine room 12 with the center line 24 in the vehicle width direction as a boundary. A wavy left side curved structure 16A having a convex portion 26 along the vehicle width direction is formed. Further, the right half of the dash panel 16 in the vehicle width direction has a convex portion 28 that bulges toward the vehicle compartment 14 side, and has a wavy side curved structure that is substantially in opposite phase to the left side curved structure 16A along the vehicle width direction. 16B.

Next, the operation of this embodiment will be described. In the dash panel 16 of this embodiment, the front side member 2
When 0 changes in the substantially vehicle width direction as indicated by the broken line in FIG. 3, the force in the substantially vehicle width direction indicated by the arrow A in FIG. 3 is applied from the rear end portion 20A of the front side member 20 to the dash panel 16. Entered in.

When a force in the direction of arrow A in FIG. 3 is input from the front side member 20 to the dash panel 16, vibration is generated in the dash panel 16 in the vehicle longitudinal direction. For example, in the vibration mode where the frequency is 180Hz or less,
When both ends of the dash panel 16 in the vehicle width direction move to the front of the vehicle body, the center portion of the dash panel 16 in the vehicle width direction moves to the rear of the vehicle body and both ends of the dash panel 16 in the vehicle width direction to the rear of the vehicle body. When the vehicle moves to, the central portion of the dash panel 16 in the vehicle width direction moves to the front of the vehicle body, and the dash panel 16 produces a sound.

The inertance of this vibration reaches about 30 dB at a frequency of 180 Hz, as shown in FIG.

In this case, the dash panel 16 of this embodiment
Then, since the left side curved structure 16A and the right side curved structure 16B have a wavy shape of substantially opposite phase with respect to the center line 22 along the vehicle width direction, the left side curved structure 16 of the dash panel 16 is formed.
The phase of the acoustic mode of A deviates from the phase of the acoustic mode of the right side curved structure 16B of the dash panel 16 by 180 ° and cancels each other. Therefore, unlike the conventional structure, it is not necessary to form a bead on the dash panel, so that vibration noise can be reduced without increasing the weight of the dash panel.

Further, in the dash panel 16 of this embodiment, since the vibration level of the dash panel 16 decreases in each frequency band, abnormal air conditioner noise, engine noise, etc. due to the resonance of the air conditioner unit directly input to the dash panel 16 are simultaneously produced. It can be reduced.

In this embodiment, the dash panel 16
The left curved structure 16A is formed with the convex portion 26 that bulges toward the engine room 12 side, and the right curved structure 16B is formed with the convex portion 28 that bulges toward the vehicle compartment 14 side. You may form. For example, FIG. 5 (A) and FIG.
As shown in (B), the left curved structure 16A of the dash panel 16 is provided with the convex portion 26 and the convex portion 3 that bulges toward the vehicle compartment 14 side.
The right curved structure 16B may have a wavy shape that is substantially opposite in phase to the left curved structure 16A that includes the convex portion 28 and the convex portion 32 that bulges toward the engine room 12 side. .

[0021]

According to the dash panel structure of the present invention, in the dash panel structure disposed between the engine room and the vehicle compartment of the vehicle, the dash panel structure is formed in the left half of the dash panel in the vehicle width direction and extends in the vehicle width direction. A left curved structure that is curved in a wavy shape, and a right curved structure that is formed in the right half of the dash panel in the vehicle width direction and has a wavy shape that is substantially in opposite phase to the left curved structure along the vehicle width direction are provided. Therefore, there is an excellent effect that vibration noise can be reduced without increasing the weight of the dash panel.

[Brief description of drawings]

FIG. 1A is a perspective view of a dash panel structure according to an embodiment of the present invention as seen obliquely from the rear of a vehicle body,
(B) is a BB line sectional view of (A).

FIG. 2 is a perspective view showing a front portion of a vehicle body to which a dash panel structure according to an embodiment of the present invention is applied, as seen from an oblique front inside of the vehicle body.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is a graph showing a relationship between vibration frequency of a dash panel and inertance.

FIG. 5 (A) is a perspective view of a dash panel structure according to another embodiment of the present invention, as viewed obliquely from the rear of the vehicle body;
(B) is a BB line sectional view of (A).

FIG. 6 is a perspective view showing a dash panel structure according to a conventional example, as viewed obliquely from the rear of the vehicle body.

[Explanation of symbols]

 12 engine room 14 vehicle compartment 16 dash panel 26 convex part 16A left side curved structure 16B side curved structure 28 convex part

Claims (1)

[Claims] 1. A dash panel structure disposed between an engine room and a vehicle compartment of a vehicle, wherein a left side curved structure is formed in a left half of the dash panel in a vehicle width direction and is curved in a wavy shape along the vehicle width direction. A dash panel structure comprising: a right half curved structure formed in the right half of the dash panel in the vehicle width direction along the vehicle width direction and having a corrugated right side curved structure substantially in opposite phase to the left side curved structure.