JP2007182113A - Front portion vehicle body structure for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain oscillation of a cowl panel while keeping foot passenger protection capability. <P>SOLUTION: In this front portion vehicle body structure for an automobile, a lower end rear edge 23d of the cowl panel 23 is fixed on a dash panel 20, and a cowl upper panel 24 for supporting a windshield 3 is fixed at an upper end front edge 23u of the cowl panel 23. A bent portion 23w constituted so as to be bend when collision load F is received is formed at the cowl panel 23 so as to extend in a vehicle width direction, and a dash front panel portion 25 overhanging forward under the cowl panel 23 is provided at the dash panel 20, and at least one portion adjacent to the bent portion 23w of the cowl panel 23 is jointed with the dash front panel portion 25 in a vehicle width direction by a joint member 45. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention has a configuration in which a lower end rear edge of a cowl panel extending in the vehicle width direction is fixed on a dash panel that divides the inner side and the outer side of the passenger compartment, and also extends in the vehicle width direction at the upper end front edge of the cowl panel. The present invention relates to a front body structure of an automobile in which a cowl upper panel that supports a lower end portion of a front window from the inside is fixed.

With respect to the front body structure of automobiles, various proposals have been made regarding shock absorbing structures from the viewpoint of so-called pedestrian protection measures.
As shown in FIG. 6, the front body structure of the automobile described in Patent Document 1 has a cowl 103 extending in the vehicle width direction fixed on a dash panel 101 that divides the inside and outside of the passenger compartment. The cowl 103 supports the lower end of the front window W from the inside. The cowl 103 is formed in a hollow closed cross-section by a cowl upper panel 103u and a cowl lower panel 103d, and a lower end rear edge of the cowl lower panel 103d is fixed to an upper end edge of the dash panel 101. And the front window W is supported by the upper end front edge of the cowl upper panel 103u.
As described above, the cowl 103 is configured such that only the lower rear edge of the cowl lower panel 103d is supported by the dash panel 101. Therefore, a load (collision load) caused by a collision between the pedestrian and the vehicle is generated via the front window W. When added to the panel 103u, the cowl 103 is easily deformed downward. For this reason, the collision load is absorbed to some extent by the deformation of the cowl 103, thereby protecting the pedestrian.

JP 2005-104179 A

However, in the above-described front body structure of an automobile, only the cowl 103 is easily deformed to improve the pedestrian protection performance (shock absorption performance), so that the cowl 103 is excited by the electric fan of the radiator. The vibration is amplified and the vibration is amplified and easily transmitted to the room. This impairs driving comfort.
The present invention has been made to solve the above-described problems, and the problem to be solved by the present invention is to suppress the vibration of the cowl panel while ensuring the pedestrian protection performance.

The above-described problems are solved by the inventions of the claims.
In the first aspect of the invention, the lower end rear edge of the cowl panel extending in the vehicle width direction is fixed on the dash panel that divides the inside and the outside of the passenger compartment, and the upper end front edge of the cowl panel is also in the vehicle width direction. A front body structure of an automobile in which a cowl upper panel that supports a lower end portion of a front window from the inside is fixed in an extended configuration, and the cowl panel collides with the cowl panel via the cowl upper panel. A bent portion configured to bend when subjected to a load is formed to extend in the vehicle width direction, and the dash panel is provided with a dash front panel portion that projects forward below the cowl panel. And the vicinity of the bent portion of the cowl panel is connected to the dash front panel portion by a connecting material at at least one point in the vehicle width direction. Characterized in that it is.

According to the present invention, the vicinity of the bent portion of the cowl panel is connected to the dash front panel portion by the connecting material at at least one place in the vehicle width direction. That is, the cowl panel has a lower end rear edge supported by the dash panel, and a bent portion and the vicinity thereof are supported by the dash front panel portion via the connecting member. For this reason, it becomes difficult for the cowl panel to be displaced in the rotational direction around the lower edge at the lower end, and the vibration of the cowl panel is suppressed. As a result, for example, radiator fan electric fan noise or the like is hardly transmitted indoors through the cowl panel.
Here, at least one connection member is provided in the vehicle width direction, and is connected in the vicinity of the bent portion of the cowl panel. For this reason, the connecting material hardly affects the deformation performance of the cowl panel. Further, since the collision load is applied to the cowl upper panel via the front window, the collision load is not directly applied to the connecting member that supports the vicinity of the bent portion of the cowl panel.
That is, it is possible to suppress the vibration of the cowl panel while ensuring the pedestrian protection performance.

According to a second aspect of the present invention, the cowl panel is provided with irregularities for increasing the surface rigidity of the cowl panel at a position deviated from the bent portion.
For this reason, the cowl panel becomes difficult to bend, and the vibration of the cowl panel itself is suppressed. Further, since the unevenness of the cowl panel is formed at a position deviated from the bent portion, the unevenness hardly affects the deformation performance of the cowl panel when a collision load is applied.
According to the invention of claim 3, the cowl panel is characterized in that a plurality of recesses that are long in the vehicle width direction are formed substantially symmetrically across the center of the vehicle body.
According to the invention of claim 4, the center of the cowl panel in the vehicle width direction is connected to the dash front panel portion by the connecting material. For this reason, the vibration of the cowl panel can be efficiently suppressed with one connecting member.

  According to the present invention, it is possible to suppress vibration of the cowl panel in a state where pedestrian protection performance is ensured.

[Embodiment 1]
Hereinafter, a front vehicle body structure of an automobile according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 5. 1 and 2 are longitudinal sectional views showing the front body structure of the automobile according to the present embodiment, FIG. 3 is a perspective view of a cowl panel used in the front body structure of the automobile, and FIG. 4 is a connecting member. FIG. FIG. 5 is a front view of an automobile provided with the front body structure according to the present embodiment.
In addition, front and rear, right and left and up and down in the figure correspond to front and rear, left and right and up and down of the automobile.

<Outline of front car structure of automobile>
First, the outline of the front body structure of an automobile will be described with reference to FIGS. Here, FIG. 1 is a vertical cross-sectional view taken along the line II in FIG. 5A, and FIG. 2 is a vertical cross-sectional view taken along the line II-II in FIG.
A dash panel 20 is formed in the front portion of the automobile in the vehicle width direction for partitioning between the compartment H and the engine room E. The lower end rear edge of the cowl panel 23 is formed on the upper end front edge 20 w of the dash panel 20. 23d and the rear edge 25b of the dash front panel portion 25 are fixed by welding or the like. The cowl panel 23 is configured to extend in the vehicle width direction on the dash panel 20, and a rear end edge 24b of the cowl upper panel 24 that also extends in the vehicle width direction is fixed to the upper end front edge 23u of the cowl panel 23. ing. The rear end edge 24 b of the cowl upper panel 24 and the upper end front edge 23 u of the cowl panel 23 are fitted into the engagement recess 5 k of the instrument panel 5. Further, the lower end portion of the front window 3 of the passenger compartment H is supported by the cowl upper panel 24.

The dash front panel portion 25 is a panel portion that projects forward from the upper edge front edge 20 w of the dash panel 20, and is configured to extend in the vehicle width direction below the cowl panel 23. A rear end edge 26 b of the shelf-like cowl front panel 26 is fixed to the upper end front edge 25 s of the dash front panel portion 25. The cowl front panel 26 constitutes a ceiling portion of the engine room E, and is configured so that the cowl louver 30 can be supported from below by a tip end portion 26f thereof.
The cowl louver 30 is a panel that covers the lower end edge of the front window 3 over the entire vehicle width direction and supports the rear end edge 43 of the engine hood 40 from below. A seal mounting portion 35, which is a pedestal having a substantially trapezoidal cross section, is formed on the front end edge of the cowl louver 30 so as to extend in the vehicle width direction. A rubber seal member 36 (weather strip) is formed on the upper surface 35 u of the seal mounting portion 35. 36) is mounted along the seal mounting portion 35.
The seal member 36 is a member that seals between the front end edge of the cowl louver 30 and the engine hood 40 that covers the front end edge of the cowl louver 30, and prevents water, foreign matter, and the like from entering the engine room E from the outside. is doing.

<About the cowl panel>
Next, the cowl panel 23 will be described with reference to FIGS. Here, FIG. 3 is a perspective view of the cowl panel 23 viewed from the vehicle interior side. The cowl panel 23 is a plate material having a vertical cross-sectional shape that is substantially "<"-shaped and protrudes toward the engine room E, and is bent at a substantially central position in the vertical direction (see FIGS. 1 and 2). ) Extending in the vehicle width direction. When a collision load F when a pedestrian collides with the automobile is applied to the cowl panel 23 via the front window 3 and the cowl upper panel 24, the cowl panel 23 is further bent at the position of the bent portion 23w. ing. Thus, the collision load F is absorbed to some extent by bending of the cowl panel 23 and the like, and pedestrians are protected.
Further, the cowl panel 23 has a substantially square recess 23k that is long in the vehicle width direction as shown in FIG. 3 in order to increase the surface rigidity of the panel surface between the bent portion 23w and the lower end rear edge 23d. A plurality of layers are formed almost symmetrically across the center.

Further, as shown in FIG. 1, the upper end surface 45 u of the connecting member 45 is welded at a position near the bent portion 23 w on the engine room E side of the cowl panel 23 at a substantially central position in the vehicle width direction of the cowl panel 23. . The lower end surface 45d of the connecting member 45 is welded to the front end edge 25s of the dash front panel portion 25. That is, the cowl panel 23 is supported from the front lower side by the connecting member 45 at a substantially central position in the vehicle width direction.
As shown in FIG. 4, the connecting member 45 has a shape obtained by bending a groove-shaped iron plate having a “U” cross section into a substantially “<” shape, and is configured to be difficult to deform even if it is a thin iron plate. Yes. Further, the connection member 45 is reduced in weight by forming the opening 45h in a portion that does not significantly affect the strength.
Note that only one connecting member 45 is provided at a substantially central position in the vehicle width direction, and the connecting member 45 is not provided at other portions as shown in FIG.

<Advantages of the front body structure of the automobile according to this embodiment>
According to the front body structure of the automobile according to the present embodiment, the cowl panel 23 is formed with a plurality of recesses 23k for increasing the surface rigidity of the cowl panel 23 at a position away from the bent portion 23w. For this reason, the cowl panel 23 becomes difficult to bend, and the vibration of the cowl panel 23 itself is suppressed.
Further, the vicinity of the bent portion 23w of the cowl panel 23 is connected to the dash front panel portion 25 and the connecting member 45 at least at one place in the vehicle width direction. That is, the cowl panel 23 is supported at the lower end rear edge 23 d by the dash panel 20, and the vicinity of the bent portion 23 w is supported by the dash front panel portion 25 through the connecting member 45. For this reason, it becomes difficult for the cowl panel 23 to be displaced in the rotational direction around the lower end rear edge 23d, and the vibration of the cowl panel 23 is suppressed.

Here, FIG. 5B shows the result of the simulation of the response vibration level (dB) at the excitation point for each frequency when the cowl panel 23 is vibrated using the excitation point. The characteristic I in FIG. 5B is a vibration characteristic (response of the cowl panel 23 to the vibration frequency (Hz) when the cowl panel 23 is not provided with the recess 23k and the cowl panel 23 is not supported by the connecting member 45. (Change in vibration level (dB)). A characteristic II represents a vibration characteristic when the cowl panel 23 is simply provided with the recess 23k and is not supported by the connecting member 45. A characteristic III represents a vibration characteristic when the cowl panel 23 is provided with a recess 23k and supported by the connecting member 45.
Thus, by providing the recess 23k in the cowl panel 23 and further supporting it by the connecting member 45, the vibration of the cowl panel 23 can be greatly reduced.
For this reason, for example, radiator fan electric fan noise (frequency about 190 Hz) or the like is hardly transmitted to the vehicle interior via the cowl panel 23.

Here, since the recess 23k of the cowl panel 23 is formed at a position excluding the bent portion 23w, the recess 23k hardly affects the deformation performance of the cowl panel 23 when the collision load F is applied.
Further, the connecting member 45 is provided in at least one place in the vehicle width direction, and is connected to the vicinity of the bent portion 23w of the cowl panel 23. For this reason, the connecting member 45 hardly affects the deformation performance of the cowl panel 23. Further, since the collision load F is applied to the cowl upper panel through the front window, the collision load F is not directly applied to the connecting member 45 that supports the vicinity of the bent portion 23w of the cowl panel.
That is, it is possible to suppress the vibration of the cowl panel 23 while ensuring the pedestrian protection performance.

<Examples of changing the front body structure of an automobile>
In addition, this invention is not limited to the said embodiment, The change in the range which does not deviate from the summary of this invention is possible. For example, in the present embodiment, an example in which a plurality of recesses 23k are formed between the bent portion 23w of the cowl panel 23 and the lower end rear edge 23d has been shown. In addition to this, the upper end front edge 23u and the bent portion 23w It is also possible to form a plurality of recesses 23k between them.
It is also possible to form a protrusion instead of the recess 23k. Further, the cross-sectional shape and the planar shape of the unevenness can be changed as appropriate.
Moreover, although the center part in the vehicle width direction of the cowl panel 23 is supported by the connecting member 45, a plurality of locations in the vehicle width direction of the cowl panel 23 can be supported by the connecting member 45, respectively.

It is a longitudinal cross-sectional view (II arrow longitudinal cross-sectional view of FIG. 5 (A)) showing the front vehicle body structure of the motor vehicle concerning Embodiment 1 of this invention. It is a longitudinal cross-sectional view (II-II arrow longitudinal cross-sectional view of FIG. 5 (A)) showing the front vehicle body structure of the motor vehicle concerning Embodiment 1 of this invention. It is a perspective view of the cowl panel used for the front body structure of a car. It is a perspective view of the connection material used for the front body structure of a motor vehicle. It is the front view (A figure) of a motor vehicle provided with the front body structure concerning Embodiment 1, and the graph showing the vibration characteristic (B figure). It is a longitudinal section showing the front body structure of the conventional automobile.

Explanation of symbols

3 Front window 20 Dash panel 23 Cowl panel 23k Recess (unevenness)
23w bent part 23u upper end front edge 23d lower end rear edge 24 cowl upper panel 25 dash front panel part 30 cowl louver 40 engine hood 45 connecting material

Claims (4)

The rear edge of the lower end of the cowl panel that extends in the vehicle width direction is fixed on the dash panel that divides the inside and the outside of the passenger compartment, and extends in the vehicle width direction at the upper edge of the cowl panel. A front body structure of an automobile to which a cowl upper panel that supports a lower end portion from the inside is fixed,
The cowl panel is formed so that a bent portion configured to be bent when the cowl panel receives a collision load via the cowl upper panel extends in the vehicle width direction.
The dash panel is provided with a dash front panel portion that projects forward under the cowl panel,
A front body structure of an automobile, wherein the vicinity of the bent portion of the cowl panel is connected to the dash front panel portion by a connecting member at at least one place in the vehicle width direction. A vehicle front body structure according to claim 1,
A front body structure of an automobile, wherein the cowl panel is formed with irregularities for increasing the surface rigidity of the cowl panel at a position deviated from the bent portion. A vehicle front body structure according to claim 2,
A front body structure of an automobile, wherein the cowl panel is formed with a plurality of recesses that are long in the vehicle width direction and are substantially symmetrical with respect to the center of the vehicle body. A vehicle front body structure according to any one of claims 1 to 3,
A front body structure of an automobile, characterized in that the center of the cowl panel in the vehicle width direction is connected to the dash front panel portion by a connecting material.

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