JPH08104256A - Cowl box structure for monocoque body - Google Patents

Abstract

PURPOSE: To provide a constitution so as to prevent vibration from being easily transmitted even when an area is enlarged. CONSTITUTION: In a cowl box 1 provided on a dash board 7 of isolating an engine room 9 from a car room 10, a plurality of holes 12 are opened partly in this cowl box, to close the holes 12 with a member of low vibration transmissibility. In this way, the cowl box 1 itself is made difficult to vibrate, also to increase a damping factor of sound ad vibration transmitted from the engine room 9, so that quietness can be obtained in the car room 10. When a hole is arranged in a position corresponding to a welding part of the cowl box 1 and the dash board 7, since the hole can be utilized also as a passage for inserting a chip of a spot welding gun, also a secondary effect of improving welding workability can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cowl box having a monocoque body, and more particularly to a structure for suppressing vibration sound transmission.

[0002]

2. Description of the Related Art In a monocoque body, the upper part of a dashboard that separates the engine room from the vehicle compartment is formed by a cowl box that extends fully in the vehicle width direction.
It is general that a supporting portion of a lower edge of the front windshield is provided on an upper side of the cowl box, and a supporting portion of a steering wheel and an instrument panel mounting portion are provided on a rear side thereof.

By the way, in order to reduce the air resistance or to expand the vehicle interior space to obtain a feeling of openness, a vehicle body design with a gentle inclination of the front windshield may be adopted. In this case, the dashboard cannot be moved forward due to the size of the engine room, and the position of the rear surface of the cowl box is smaller than that of the conventional one because of the provision of the steering wheel support and the instrument panel attachment. Cannot be changed significantly. for that reason,
The cross-sectional shape of the cowl box becomes long in the front and rear, and the area of the sheet metal constituting the upper and lower surfaces of the cowl box becomes large.

[0004]

Therefore, the cowl box is likely to vibrate due to the sound and vibration generated in the engine room, and the sound may be easily transmitted to the vehicle interior. In particular, this tendency is more prominent on the upper surface side formed by a single plate, as compared with the lower surface side on which a relatively high rigidity is obtained because the dashboard is connected.

The present invention has been devised in order to eliminate such disadvantages of the prior art, and its main purpose is to:
It is an object of the present invention to provide a cowl box structure of a monocoque body that is configured to make it difficult for vibration to be transmitted even if the area is increased.

[0006]

According to the present invention, a cowl box provided at an upper portion of a dashboard that separates an engine room from a vehicle compartment is provided with a plurality of holes in a part thereof. This is achieved by opening and closing the hole with a member having a low vibration transmissibility.

[0007]

With this structure, the cowl box itself is less likely to vibrate, and the sound and vibration transmitted from the engine room are more efficiently damped.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to specific embodiments shown in the accompanying drawings.

1 and 2 show a cowl box portion of a monocoque body constructed according to the present invention. The cowl box 1 is formed by joining an upper member 2 and a lower member 3 formed by press forming a steel plate,
It has a substantially flat box shape and extends fully in the vehicle width direction near the base of the front pillar 4 of the vehicle body. A support portion 6 at the lower edge of the front windshield 5 is formed on the front edge of the upper member 2, and an upper edge of the dashboard 7 raised from the vehicle body floor (not shown) is formed on the lower surface of the lower member 3. It is connected.

The inside of the cowl box 1 is partitioned by a bulkhead 8 which is fixedly provided in the middle portion in the front-rear direction.
The engine room 9 side functions as an air scoop duct whose front upper surface is open, and the vehicle compartment 10 side basically functions as a structural member with a closed cross section. The closed cross-section portion 11 on the side of the passenger compartment 10
The inner space of is used as a ventilation duct of the air conditioner.

On the upper surface of the upper member 2 on the side of the closed cross section 11, a plurality of oval holes 12 are arranged in a row in the vehicle width direction. The hole 12 is closed by a cap 13 made of an elastomer material.

Each of the holes 12 formed in the upper member 2 corresponds to a connecting portion between the lower member 3 and the dashboard 7, and the cowl box 1 formed in advance in a closed cross section is attached to the upper edge of the dashboard 7. The spot welding gun functions as a passage for reaching the tip 14 of the spot welding gun to the inner surface of the lower member 3 during spot welding.

As shown in the above embodiment, in the cowl box structure in which the area of the sheet metal constituting the upper member 2 is large because the front windshield 5 is gently inclined, the cowl box 1 itself is Since it is easy to vibrate, it becomes easy to transmit sound into the vehicle interior 10. Therefore, in the present invention, a plurality of holes 12 are opened in the closed cross-section portion 11 of the cowl box 1, and a cap 13 made of a material having a low vibration transmissibility is fitted into the holes 12.
As a result, the upper member 2 of the cowl box 1 is less likely to vibrate, and at the same time, the engine room 9 to the vehicle compartment 10
Sounds and vibrations transmitted to the cap 13 are effectively damped by the cap 13.

[0014]

As described above, according to the present invention, the cowl box itself is less likely to vibrate and the efficiency of damping the sound and vibration transmitted from the engine room is increased. Therefore, a great effect can be obtained in quieting the passenger compartment. Can play. Also, by arranging a hole at a position corresponding to the welded portion of the cowl box and the dashboard, it can be used as a passage for inserting the tip of the spot welding gun, so there is also a secondary effect that welding workability can be improved. can get.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a cowl box according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a cowl box according to the present invention.

[Explanation of symbols]

 1 Cowl Box 2 Upper Member 3 Lower Member 4 Front Pillar 5 Front Windshield 6 Support 7 Dashboard 8 Bulkhead 9 Engine Room 10 Vehicle Cabin 11 Closed Section 12 Hole 13 Cap 14 Weld Gun Tip

Claims (1)

[Claims] 1. A cowl box structure provided on an upper part of a dashboard that isolates an engine room from a vehicle compartment, wherein a plurality of holes are formed in a part of the cowl box, and the holes have a vibration transmissibility A cowl box structure with a monocoque body characterized by being closed with a low member.