JP3451139B2 - Monocoque body cowl box structure - Google Patents

Description

Description: 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 transmission of vibration noise. 2. Description of the Related Art In a monocoque body, an upper portion of a dashboard separating an engine room and a vehicle compartment is constituted by a cowl box extending fully in a vehicle width direction.
Generally, a support portion of a lower edge of the front windshield is provided on an upper side of the cowl box, and a support portion of a steering wheel and a mounting portion of an instrument panel are provided on a rear side. [0003] By the way, in order to reduce the air resistance or to enlarge the cabin space and obtain a sense of openness, a vehicle body design in which the inclination of the front windshield is gentle may be adopted. In this case, the dashboard cannot be moved forward due to the size of the engine room, and the rear surface of the cowl box is also located at a lower position than before due to the provision of the steering wheel support and instrument panel mounting. Cannot be changed significantly. for that reason,
The cross-sectional shape of the cowl box becomes longer in the front-rear direction, and the area of the sheet metal forming the upper and lower surfaces of the cowl box becomes larger. [0004] Therefore, the cowl box is likely to vibrate due to the sound or vibration generated in the engine room, and the sound may be easily transmitted to the vehicle interior. In particular, this tendency is more conspicuous on the upper surface formed of a single plate than on the lower surface where relatively high rigidity is obtained because the dashboard is connected. The present invention has been devised to solve such disadvantages of the prior art, and its main objects are as follows.
An object of the present invention is to provide a cowl box structure of a monocoque body configured to make it difficult for vibration to be transmitted even when the area is increased. [0006] According to the present invention, the above objects can be attained by providing an upper member (2) and a lower member (3).
It is joined in a flat box shape, and the front edge of the dashboard (7) that separates the engine room from the cabin
Serial cowl box lower member is welded (1), wherein
The lower member and the dashboard in the upper member
A plurality of holes (12) are formed at positions corresponding to the welded portions of the member, and the holes (12) are made of a member having a low vibration transmissibility (elastomer material cap).
This is achieved by having it closed in step 13) . According to the above construction, the cowl box can be
When performing spot welding on the upper edge of the
Make the tip of the welding gun reach the inner surface of the lower member through the hole
Therefore, welding workability is improved. Moreover
By closing the hole with a member having a low vibration transmissibility, the cowl box itself is less likely to vibrate, and the attenuation efficiency of sound and vibration transmitted from the engine room is increased. Hereinafter, the structure of the present invention will be described in detail with reference to specific embodiments shown in the accompanying drawings. FIG. 1 and FIG. 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 near the base of the front pillar 4 of the vehicle body in the vehicle width direction. At the front edge of the upper member 2, a support portion 6 at the lower edge of the front windshield 5 is formed, and at the lower surface of the lower member 3, an upper edge of a dashboard 7 raised from a vehicle body floor (not shown) is formed. It is connected. The inside of the cowl box 1 is partitioned by a bulkhead 8 fixed at an intermediate 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 room 10 side basically functions as a structural member having a closed cross section. This closed section 11 on the side of the cabin 10
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 section 11, a plurality of oblong holes 12 are arranged 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 a closed cross section in advance is connected to the upper edge of the dashboard 7. When spot welding is performed on the inner surface of the lower member 3, the tip 14 of the spot welding gun functions as a passage. As shown in the above embodiment, in the cowl box structure in which the area of the sheet metal forming the upper member 2 is large because the front windshield 5 has a gentle inclination, the cowl box 1 itself is not used. Since the vibration easily occurs, the sound is easily transmitted into the vehicle interior 10. Therefore, in the present invention, a plurality of holes 12 are formed in the closed cross section 11 of the cowl box 1, and a cap 13 formed of a material having a low vibration transmissibility is fitted into the holes 12.
As a result, the upper member 2 itself of the cowl box 1 is less likely to vibrate, and at the same time, the
Is effectively attenuated by the cap 13. As described above, according to the present invention, the cowl box is provided.
A hole is formed in the upper member of the box, and this hole is
By closing with a low member, the cowl box itself does not easily vibrate, and the attenuation efficiency of the sound and vibration transmitted from the engine room is increased, so that a great effect can be achieved in quieting the vehicle interior. Also, a hole located at the position corresponding to the weld between the cowl box and the dashboard
Since <br/> that can be plugged tip of a spot welding gun from large effect is obtained in terms of Ru enhances weldability.

[Brief description of the 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 the 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 cabin 11 Closed section 12 holes 13 caps 14 Welding Gun Tips

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B62D 25/08 B62D 23/00 B62D 25/14

Claims (1)

(57) [Claims] [Claim 1] The upper member and the lower member are generally flat boxes.
The lower member is welded to the upper edge of the dashboard that separates the engine room from the cabin.
The lower member and the dash board of the upper member.
A cowl box structure for a monocoque body, characterized in that a plurality of holes are opened at positions corresponding to the welded portions with the arm and the holes are closed with a member having a low vibration transmissibility.