JP7795100B2 - Dash panel and front body structure - Google Patents

Description

The present invention relates to an automobile dash panel and front body structure.

Autonomous driving technologies, which have been developed in recent years, require the installation of sensors and cameras to recognize road conditions and pedestrians, as well as electronic devices that perform image processing, etc., which increases the weight of the vehicle body. Furthermore, in recent vehicle body designs, there has been a trend toward increasing the size of vehicles to expand interior space in order to improve passenger comfort, which also contributes to an increase in vehicle weight.

Ensuring vehicle crash performance under these circumstances requires thickening of structural components. In particular, improving a vehicle's crash performance in frontal collisions requires thickening of relatively large components such as front side members, which has a significant impact on the weight of the vehicle body. Therefore, efforts are being made to increase the strength of interior panels in order to prevent the thickness of structural components from increasing.

One example of such an interior panel is the dash panel. The dash panel is located near the feet of occupants (driver and front passenger), and in the event of a frontal collision, it plays a role in distributing the collision load from the front side member to the side sill and floor tunnel. For this reason, from the perspective of occupant protection, it is desirable to increase the strength of the dash panel.

As a technology related to dash panels, Patent Document 1 discloses a vehicle front structure in which the dash panel, floor panel, and floor tunnel are reinforced with reinforcing members. Furthermore, Patent Document 2 discloses a vehicle front structure that focuses on the joining structure between the dash panel and the front pillar.

International Publication No. 2013/080305 Patent No. 6076774

In order to increase the strength of the dash panel while suppressing an increase in vehicle weight, it is desirable to increase the strength of the dash panel itself. However, the vehicle front structure described in Patent Document 1 is designed to improve collision performance using reinforcing members, so an increase in weight due to the addition of reinforcing members is unavoidable. Furthermore, the vehicle front structure described in Patent Document 2 is designed to increase rigidity against inputs in the vehicle length direction and the ability to absorb loads from above the vehicle without using reinforcing members, but does not consider increasing the strength of the dash panel itself.

The present invention was made in consideration of the above circumstances, and aims to improve the strength of the dash panel alone.

One aspect of the present invention that solves the above-mentioned problems is a dash panel for an automobile comprising: a front wall, a bottom wall, a wheel arch portion, an opening, a flange, and a first ridge portion; the front wall is a wall portion that extends in the vehicle height and width directions; the bottom wall is a wall portion that extends in the vehicle length and width directions; the wheel arch portions are formed at both ends of the dash panel in the vehicle width direction; the opening is formed in the center of the dash panel in the vehicle width direction, from the midpoint in the vehicle height direction to the rear end in the vehicle length direction; the flange protrudes from the front wall and the bottom wall toward the interior of the vehicle around the opening; the first ridge portion is formed continuously around the periphery of the flange between the front wall and the flange, and between the bottom wall and the flange ; and the first ridge portion is a bent portion where the radius of curvature at the boundary between two adjacent surfaces is 25 to 70 mm and the opening angle between the two adjacent surfaces is 145° or less .

Another aspect of the present invention is a front body structure for an automobile, characterized by comprising the above-mentioned dash panel, a front side member attached to the dash panel, and a floor panel joined to the dash panel.

This invention makes it possible to improve the bearing strength of the dash panel itself.

1 is an explanatory diagram showing a schematic configuration of a vehicle body front structure according to a first embodiment of the present invention; This is a view of the dash panel alone as seen from inside the vehicle. This is a view of the dash panel alone as seen from outside the vehicle. FIG. 3 is a diagram showing a cross section taken along line II of FIG. 2. FIG. 10 is an explanatory diagram for explaining the definition of a ridge line portion. FIG. 10 is an explanatory diagram showing a schematic configuration of a vehicle front body structure according to a second embodiment of the present invention. This is a view of the dash panel alone as seen from inside the vehicle. This is a view of the dash panel alone as seen from outside the vehicle. FIG. 8 is a cross-sectional view taken along line II-II of FIG. 7. FIG. 10 is an explanatory diagram for explaining the definition of a representative length of a convex portion. FIG. 2 is an explanatory diagram showing the first surface portion (the surface on which the convex portions are formed) viewed from a direction perpendicular to the first surface portion. 12 is an explanatory diagram for explaining the intervals between the convex portions, and is a cross-sectional view taken along line III-III in FIG. 11. FIG. FIG. 10 is a diagram showing the results of simulation (1). FIG. 10 is a diagram showing the results of simulation (1). FIG. 10 is a diagram showing the results of simulation (2).

Embodiments of the present invention will be described below with reference to the drawings. Note that in this specification and drawings, elements having substantially the same functional configuration will be designated by the same reference numerals, and redundant description will be omitted.

First Embodiment
1 is an explanatory diagram showing a schematic configuration of a vehicle front body structure according to a first embodiment. In this specification and the drawings, the X direction is the vehicle length direction, the Y direction is the vehicle width direction, and the Z direction is the vehicle height direction.

The vehicle front body structure 1 includes a dash panel 10, front side members 20, and a floor panel 30.

The dash panel 10 is a partition wall located between the engine compartment (not shown) and the interior space of the vehicle. In this specification, the term "dash panel" refers to a component formed by processing (e.g., pressing) a single sheet of plate material, and does not include a structure that functions as a dash panel by combining multiple components.

The material of the dash panel 10 is not particularly limited, and can be, for example, a metal material such as steel plate with a tensile strength of 270 MPa or more, or aluminum alloy or magnesium alloy member. If steel plate is used as the material for the dash panel 10, the tensile strength of the steel plate is more preferably 440 MPa or more, and even more preferably 590 MPa or more or 780 MPa or more. The plate thickness of the dash panel 10 is, for example, 0.8 to 5 mm.

The configuration of the dash panel 10 according to the first embodiment will be described in detail below. Figure 2 is a view of the dash panel alone as seen from the inside of the vehicle. Figure 3 is a view of the dash panel alone as seen from the outside of the vehicle. Figure 4 is a cross-sectional view taken along line I-I in Figure 2.

The dash panel 10 has a front wall 11, a bottom wall 12, a wheel arch portion 13, an opening 14, and a flange 15.

The front wall 11 is a wall facing the engine compartment that extends in the vehicle height direction (Z direction) and vehicle width direction (Y direction). This front wall 11 has a first surface portion 11a, a second surface portion 11b, and a third surface portion 11c.

The first surface portion 11a is a wall portion on which a convex portion 50, described below, is formed. The second surface portion 11b is a wall portion that is recessed forward in the vehicle length direction (X direction) relative to the first surface portion 11a, at the center of the first surface portion 11a in the vehicle width direction (Y direction). In this embodiment, both the first surface portion 11a and the second surface portion 11b are flat, but they may have curved surfaces depending on the vehicle body structure. Also, depending on the vehicle body structure, the second surface portion 11b may not exist, and the area of the second surface portion 11b may be formed by the first surface portion 11a.

The third surface portion 11c is a wall portion for attaching the front side member 20 and is located below the first surface portion 11a. The area indicated by the two-dot chain line within the plane of the third surface portion 11c in Figure 3 is the attachment surface 21 between the dash panel 10 and the front side member 20. The dash panel 10 and the front side member 20 are joined by welding means such as spot welding.

The above-mentioned mounting surface 21 is preferably a plane (vertical plane) perpendicular to the horizontal plane. This makes it easier to maintain the posture of the front side member 20 when an axial load is input from the front of the front side member 20 attached to the mounting surface 21, thereby increasing the strength of the front vehicle body structure 1.

The bottom wall 12 is a wall portion that extends in the vehicle length direction (X direction) and vehicle width direction (Y direction) and is joined to the floor panel 30. This bottom wall 12 has an inclined surface portion 12a and a joining surface portion 12b.

The inclined surface portion 12a is the portion that connects to the front wall 11, and the joint surface portion 12b is the portion that is joined to the floor panel 30 near the rear end in the vehicle length direction. The joint surface portion 12b and the floor panel 30 are joined by welding means such as spot welding. In this embodiment, the joint surface portion 12b is a substantially horizontal surface.

As shown in Figures 2 and 3, the wheel arch portion 13 is a portion that surrounds the tire (not shown) at both ends in the vehicle width direction (Y direction), and has a shape that bulges toward the inside of the vehicle so as not to interfere with the tire.

The opening 14 is provided so that the dash panel 10 does not interfere with the floor tunnel (not shown). This opening 14 is formed in the center of the dash panel 10 in the vehicle width direction (Y direction), from the middle in the vehicle height direction (Z direction) to the rear end in the vehicle length direction (X direction).

The flange 15 is formed by processing a single sheet of plate material and is provided so as to surround the periphery of the opening 14. This flange 15 has a shape that protrudes toward the interior of the vehicle from each of the first surface portion 11a and third surface portion 11c of the front wall 11, and the inclined surface portion 12a and joint surface portion 12b of the bottom wall 12.

As shown in FIG. 3, the dash panel 10 has a first ridge 41, a second ridge 42, and a third ridge 43 between the front wall 11, the bottom wall 12, and the wheel arch portion 13.

The first ridge portion 41 is a ridge portion located between the front wall 11 and the flange 15, and between the bottom wall 12 and the flange 15. In other words, the first ridge portion 41 is a ridge portion sandwiched between the flange 15 and each of the first surface portion 11a and the third surface portion 11c of the front wall 11, and also sandwiched between the flange 15 and the inclined surface portion 12a of the bottom wall 12. This first ridge portion 41 is formed continuously around the flange 15 to follow the shape of the flange 15, and is curved three-dimensionally.

The second ridge portion 42 is a ridge portion formed continuously between the front wall 11 and the wheel arch portion 13, and between the bottom wall 12 and the wheel arch portion 13. In other words, the second ridge portion 42 is a ridge portion sandwiched between the first surface portion 11a and the third surface portion 11c of the front wall 11 and the wheel arch portion 13, and also sandwiched between the inclined surface portion 12a of the bottom wall 12 and the wheel arch portion 13.

The third ridge portion 43 is a ridge portion located between the first ridge portion 41 and the second ridge portion 42. In other words, the third ridge portion 43 is a ridge portion sandwiched between the third surface portion 11c of the front wall 11 and the inclined surface portion 12a of the bottom wall 12. This third ridge portion 43 is formed continuously from the first ridge portion 41 to the second ridge portion 42, connecting the first ridge portion 41 and the second ridge portion 42.

In this specification, "ridge line portion" refers to a bent portion at the boundary between adjacent surfaces A and B, as shown in Figure 5, where the radius of curvature R is 25 to 70 mm and the opening angle θ between surfaces A and B is 145° or less. A bent portion that meets these conditions contributes to improving the surface rigidity of each of the adjacent surfaces A and B.

Whether a bent portion between two adjacent surfaces is a ridgeline is determined as follows. For example, in the bent portion at point _P1 shown in Figure 3, the two adjacent surfaces are the third surface 11c of the front wall 11 and the inclined surface 12a of the bottom wall 12. If the radius of curvature of the bent portion at the boundary between these two surfaces 11c and 12a is 25 to 70 mm and the opening angle between the two surfaces 11c and 12a is 145° or less, the bent portion is determined to be a ridgeline.

At point _P2 , the two adjacent surfaces are the third surface portion 11c of the front wall 11 and the flange 15, and whether or not the bent portion is a ridgeline portion is determined from the radius of curvature of the bent portion at the boundary between these two surfaces 11c, 15 and the opening angle between the two surfaces 11c, 15. At point _P3 , the two adjacent surfaces are the inclined surface portion 12a of the bottom wall 12 and the flange 15, and whether or not the bent portion is a ridgeline portion is determined from the radius of curvature of the bent portion at the boundary between these two surfaces 12a, 15 and the opening angle between the two surfaces 12a, 15.

In addition, in this specification, "a continuous ridge line" refers to a state in which the ridge line extends continuously without interruption. For example, if an opening (not shown) is provided in a portion of the first ridge line 41 shown in Figure 3 between the third surface portion 11c and the flange 15, the ridge line on either side of the opening will be in an interrupted state. In other words, in that case, there will be no "ridge line that continues around the flange 15."

The above describes the general configuration of the dash panel 10.

In the dash panel 10 according to this embodiment, the first ridge 41 is formed continuously across the front wall 11 and the bottom wall 12. As a result, when an axial load is input from the front side member 20 to the front wall 11, the restraining force from the flange 15 and the first ridge 41 is increased, thereby increasing the surface rigidity of the front wall 11 and the bottom wall 12 near the flange 15. As a result, deformation of the front wall 11 and the bottom wall 12 near the flange 15 can be suppressed during a frontal collision, improving the strength of the dash panel 10 as a single unit.

Furthermore, because the strength of the dash panel 10 alone can be improved without the need for reinforcing members (not shown), the weight of the vehicle body front structure 1 can be reduced by the weight of the reinforcing members. In addition, by not providing reinforcing members, the foot space for occupants can be expanded by the amount of the thickness of the reinforcing members, improving comfort inside the vehicle.

Furthermore, in the event of a frontal collision, when an axial load is input to the front side member 20, the dash panel 10 is less likely to deform, making it easier for the front side member 20 joined to the dash panel 10 to maintain its original position. This allows the front side member 20 to withstand a greater load. In addition, the dash panel 10 is less likely to deform, which increases the efficiency with which the collision load is transmitted from the front side member 20 to the side sill (not shown) and floor tunnel (not shown), improving the strength of the front vehicle body structure 1.

In addition, the dash panel 10 according to this embodiment is provided with the second ridgeline 42 and the third ridgeline 43 in addition to the first ridgeline 41, thereby improving the surface rigidity of each wall portion adjacent to each of the ridgelines 41 to 43. In other words, the surface rigidity of the entire dash panel 10 is improved, resulting in even greater crash resistance and quieter operation than when only the first ridgeline 41 is provided.

In order to further enhance this effect of improving resistance to collisions, it is preferable that the mounting surface 21 of the front side member 20 be located between the first ridgeline 41 and the second ridgeline 42 and above the third ridgeline 43, as shown in Figure 3. The area near the first ridgeline 41 to the third ridgeline 43 has particularly high surface rigidity, so by mounting the front side member 20 in this area, the posture of the front side member 20 is more effectively maintained during a frontal collision.

Second Embodiment
Fig. 6 is an explanatory diagram showing a schematic configuration of a vehicle body front structure according to a second embodiment. Fig. 7 is a diagram showing the dash panel alone as viewed from the inside of the vehicle. Fig. 8 is a diagram showing the dash panel alone as viewed from the outside of the vehicle. Fig. 9 is a cross-sectional view taken along line II-II in Fig. 7.

In the vehicle body front structure 1 according to the second embodiment, a plurality of protrusions 50 (bead portions) are provided on the first surface portion 11a of the front wall 11 of the dash panel 10 according to the first embodiment.

The protrusion 50 protrudes forward in the vehicle length direction relative to the first surface 11a. The protrusion 50 may also protrude rearward in the vehicle length direction relative to the first surface 11a.

The protrusions 50 are formed in a diamond shape when viewed from a direction perpendicular to the first surface 11a. However, the protrusions 50 may also be, for example, trapezoidal or parallelogram-shaped, and are not limited to a rectangle but may also be polygonal or circular, such as a perfect circle or ellipse. Furthermore, there are no particular limitations on the arrangement of the multiple protrusions 50.

The first surface portion 11a has a relatively large area compared to the other two surfaces, the second surface portion 11b and the third surface portion 11c, and accounts for the majority of the overall area of the front wall 11. In such a first surface portion 11a, vibrations are likely to occur starting from the flat area, and road noise from the front upper mount (not shown) is easily transmitted.

On the other hand, if multiple protrusions 50 as described above are provided, the number of continuous flat areas within the first surface portion 11a is reduced, thereby increasing the surface rigidity of the first surface portion 11a. This enhances the vibration suppression effect of the dash panel 10 and improves quietness within the vehicle. In other words, the dash panel 10 according to the second embodiment not only improves the strength of the dash panel 10 itself, as described in the first embodiment, but also improves quietness within the vehicle.

Furthermore, the vehicle body front structure 1 having the dash panel 10 according to the second embodiment is provided with multiple protrusions 50 spaced apart on the front wall 11, thereby reducing equivalent radiation power, enhancing noise and vibration suppression effects and improving quietness inside the vehicle.

The following describes the preferred arrangement of the convex portions. To begin with, the representative length of the convex portion 50 will be explained. Figure 10 is an explanatory diagram for explaining the definition of the representative length of the convex portion 50.

The representative length is the length from the center of gravity of the top surface 51 of the convex portion 50 to the outer edge of the convex portion 50 that is farthest from the center of gravity of the top surface 51 when the convex portion 50 is viewed from a direction perpendicular to the top surface 51 of the convex portion 50. For example, as shown in FIG. 10(a), if the convex portion 50 is circular, the radius of the circle is the representative length, and as shown in FIG. 10(b), if the convex portion 50 is elliptical, the semi-major axis of the ellipse is the representative length. Also, as shown in FIGS. 10(a) and 10(b), if the convex portion 50 is a regular polygon, the length from the center of gravity of the top surface 51 to the vertex is the representative length.

Regarding the preferred arrangement of the convex portions 50, Figure 11 is an explanatory diagram showing the first surface portion 11a viewed from a direction perpendicular to the first surface portion 11a (the surface on which the convex portions 50 are formed).

It is preferable that the multiple protrusions 50 are arranged so that the representative lengths of the multiple protrusions 50 are aligned in at least one direction when viewed from a direction perpendicular to the first surface 11a.

Specifically, in the example shown in Figure 11, each protrusion 50 has a regular square shape, so the representative length of the multiple protrusions 50 is the length from the center of the diagonal to one of the vertices. In other words, the direction of the representative length of the multiple protrusions 50 is the direction from the center of the diagonal to one of the vertices.

The direction D _A (Z direction in this embodiment) shown in Fig. 11 is the same as the direction of the representative lengths of the multiple protrusions 50, and the representative length directions of the multiple protrusions 50 are aligned in this direction D _A. In addition, in the example shown in Fig. 11, the protrusions 50 have a regular square shape, so there are multiple representative length directions. The direction D _B (Y direction in this embodiment) shown in Fig. 11 is different from the direction D _A , but this direction D _B is also the direction of the representative lengths of the multiple protrusions 50.

In other words, in the example shown in Figure 11, multiple protrusions 50 are arranged so that the representative lengths are aligned in two directions. When the representative lengths of multiple protrusions 50 are aligned in at least one direction, the regularity of the arrangement of multiple protrusions 50 is increased, and variations in surface rigidity on the first surface portion 11a can be reduced. Furthermore, to further enhance this effect, it is preferable that the representative lengths of all protrusions 50 be aligned in at least one direction.

Note that the direction D _C shown in FIG. 11 is a direction that is not related to the representative length of each of the convex portions 50, and therefore this direction D _C is not a direction in which the representative lengths of the plurality of convex portions 50 are the same.

From the perspective of further increasing the surface rigidity of the first surface portion 11a, it is preferable that the surface occupancy rate of the protrusions 50 on the first surface portion 11a be 25% or more. The surface occupancy rate is a value calculated by "total area of the top surfaces of the multiple protrusions 50 / area of the surface on the front wall 11 on which the multiple protrusions 50 are formed."

11 , the sum of the areas S ₁ , S ₂ , S ₃ , ..., S _n-1 , S _n of the top surfaces of the respective protrusions 50 is the "total area of the top surfaces of the plurality of protrusions 50." The "area of the surface on which the plurality of protrusions 50 are formed" is the area of the first surface 11a. The area of the first surface 11a is the area when the first surface 11a is flat and does not have the plurality of protrusions 50 formed thereon. The second surface 11b, which does not exist within the first surface 11a, is not a surface on which the plurality of protrusions 50 are formed, and therefore the area of the second surface 11b is not included in the "area of the surface on which the plurality of protrusions 50 are formed."

From the perspective of increasing the surface rigidity of the first surface portion 11a, the surface coverage of the above-mentioned protrusions 50 is more preferably 40% or more, and even more preferably 50% or 60% or more. On the other hand, there is no particular upper limit to the surface coverage, but from the perspective of facilitating the molding of the protrusions 50, the surface coverage is preferably 90% or less, and more preferably 80% or less.

Regarding the spacing between the multiple protrusions 50, Fig. 12 is an explanatory diagram for explaining the spacing between the protrusions 50, and is a diagram showing a cross section taken along III-III in Fig. 11. More specifically, Fig. 12 is a diagram in which the first surface 11a is cut in a direction perpendicular to the first surface 11a so as to include the direction in which the representative lengths of the multiple protrusions 50 are aligned (direction D _A or direction D _B in Fig. 11).

Regarding the spacing between the protrusions 50, in the cross section shown in FIG. 12, the ratio (d ₁ /d ₂ ) of the length d ₁ of the top surface of a protrusion 50 to the spacing d ₂ between that protrusion 50 and the adjacent protrusion 50 is preferably 1.5 to 2.5. Furthermore, the representative length L of the protrusions 50 is preferably 4 to 20 mm. By satisfying these conditions, the protrusions 50 can be arranged in a balanced manner across the entire first surface 11a, and the flat area on the top surface 51 of the protrusions 50 and the flat area of the first surface 11a between each protrusion 50 can be reduced. This increases the surface rigidity of the entire first surface 11a.

The above describes one example of an embodiment of the present invention, but the present invention is not limited to such an example. It is clear that a person skilled in the art could conceive of various modifications or alterations within the scope of the technical ideas set forth in the claims, and it is understood that these naturally fall within the technical scope of the present invention.

For example, in the above embodiment, a vehicle body front structure 1 was illustrated in which the dash panel 10 was not provided with a reinforcing member (not shown). However, if the product meets the weight requirements, interior space size, and other specifications, a reinforcing member may be provided in the dash panel 10. Even in this case, the effect of improving the bearing strength of the dash panel 10 alone can still be obtained.

<Simulation (1)>
In order to confirm the collision performance of the dash panel according to the embodiment of the present invention, a collision simulation was carried out using an analytical model in which a dash panel having the structure shown in Fig. 8 was mounted on a vehicle model. This simulation was an analysis simulating a full-lap test, and was carried out under the conditions of a vehicle speed of 56 km/h, a rigid barrier made of steel plate.

As a comparative example for performance comparison, a simulation was also conducted on a vehicle model equipped with a dash panel of conventional structure. The conventional structure in this simulation is a structure having only the second ridge line portion of the first to third ridge line portions described in the previous embodiment.

Figure 13 shows the simulation results for the maximum load on the floor tunnel of the vehicle model. Figure 14 shows the simulation results for the amount of setback of the dash panel. Note that the simulations in Figures 13 and 14 were performed using models with different material tensile strengths of 270 MPa and 1180 MPa.

As shown in Figure 13, the structure of the example has a higher maximum load on the floor tunnel than the structure of the comparative example, improving the bearing strength of the dash panel and transmitting more load to the floor tunnel. Furthermore, as shown in Figure 14, the structure of the example has a smaller amount of setback of the dash panel than the structure of the comparative example, improving occupant safety.

Furthermore, when comparing the results of the Examples and Comparative Examples when the tensile strength was 270 MPa with the results of the Examples and Comparative Examples when the tensile strength was 1180 MPa, the improvement in the effects of the Examples over the Comparative Examples was greater when the tensile strength was 1180 MPa. In other words, the structure according to the Examples of the present invention is useful when applied to higher strength materials, which effectively increases the yield strength of the dash panel 10 alone.

<Simulation (2)>
A simulation was carried out to simulate a measurement test of equivalent radiation power. This simulation was carried out under the condition that the front upper mount was vibrated for the vehicle models of the example and comparative example in simulation (1). The results are shown in Figure 15.

As shown in Figure 15, the structure of the example has reduced equivalent radiation power in the 200-250 Hz and 300-350 Hz frequency bands compared to the structure of the comparative example. In other words, the structure of the example improves quietness inside the vehicle.

The above describes an embodiment of the present invention. While the above explanation provides several examples of dash panel configurations, the dash panel configurations can be combined in any way as long as they do not impair the functionality of the dash panel.

For example, the following configurations also fall within the technical scope of the present invention.
[1] A dash panel for an automobile,
a front wall, a bottom wall, a wheel arch portion, an opening, a flange, and a first ridge portion;
the front wall is a wall portion extending in a vehicle height direction and a vehicle width direction,
the bottom wall is a wall portion extending in the vehicle length direction and the vehicle width direction,
The wheel arch portions are formed at both ends of the dash panel in a vehicle width direction,
The opening is formed in a center portion of the dash panel in a vehicle width direction, from a midpoint in a vehicle height direction to a rear end in a vehicle length direction,
the flanges protrude from the front wall and the bottom wall toward the vehicle interior around the opening,
The dash panel, wherein the first ridge portion is formed continuously around the flange between the front wall and the flange and between the bottom wall and the flange.
[2] A second ridge portion and a third ridge portion are provided,
the second ridge line portion is formed continuously between the front wall and the wheel arch portion and between the bottom wall and the wheel arch portion,
The dash panel according to [1], wherein the third ridge portion extends from the first ridge portion to the second ridge portion.
[3] The front wall has a mounting surface to which a front side member is attached,
The dash panel according to [2], wherein the mounting surface is located between the first ridge portion and the second ridge portion and above the third ridge portion.
[4] The dash panel according to [3], wherein the mounting surface is a surface perpendicular to a horizontal plane.
[5] The dash panel according to any one of [1] to [4], wherein the front wall has a plurality of protrusions protruding in a direction perpendicular to the front wall.
[6] The dash panel described in [5], characterized in that the plurality of protrusions are arranged so that the representative length directions of the plurality of protrusions are aligned in at least one direction when viewed from a direction perpendicular to the surface on which the protrusions are formed.
[7] The dash panel described in [6], characterized in that the surface occupancy rate of the convex portions calculated by "total area of the top surfaces of the plurality of convex portions / area of the surface on which the plurality of convex portions are formed in the front wall" is 25% or more.
[8] In a cross section perpendicular to the surface on which the protrusions are formed, cut so as to include a direction in which the representative lengths of the plurality of protrusions are aligned, the ratio (d ₁ /d ₂ ) of the top surface length d ₁ of the protrusion to the distance d ₂ between the protrusion and an adjacent protrusion is 1.5 to 2.5,
The dash panel according to [6] or [7], wherein the representative length of the convex portion is 4 to 20 mm.
[9] A dash panel according to any one of [1] to [8], characterized in that it is formed from a steel plate having a tensile strength of 590 MPa or more.
[10] A front body structure of an automobile,
[1] to [9], and a dash panel according to any one of [1] to [9].
a front side member attached to the dash panel;
a floor panel joined to the dash panel.

In the dash panel described above, the provision of the first ridge line portion was essential from the perspective of solving the problem of improving the bearing strength of the dash panel alone. However, from the perspective of solving the problem of improving quietness inside the vehicle, the provision of the convex portion is essential, but the provision of the first ridge line portion is not. In other words, the following examples of aspects of the invention that solve the problem of improving quietness inside the vehicle may also be used.

[1] A dash panel for an automobile,
a front wall, a bottom wall, a wheel arch portion, an opening, a flange, and a first ridge portion;
the front wall is a wall portion extending in a vehicle height direction and a vehicle width direction,
the bottom wall is a wall portion extending in the vehicle length direction and the vehicle width direction,
The wheel arch portions are formed at both ends of the dash panel in a vehicle width direction,
The dash panel is characterized in that the front wall has a plurality of protrusions protruding in a direction perpendicular to the front wall.
[2] The dash panel described in [1], characterized in that the plurality of protrusions are arranged so that the representative length directions of the plurality of protrusions are aligned in at least one direction when viewed from a direction perpendicular to the surface on which the protrusions are formed.
[3] The dash panel described in [1] or [2], characterized in that the surface occupancy rate of the convex portions calculated by "total area of the top surfaces of the plurality of convex portions / area of the surface on which the plurality of convex portions are formed in the front wall" is 25% or more.
[4] In a cross section perpendicular to the surface on which the protrusions are formed, cut so as to include a direction in which the representative lengths of the plurality of protrusions are aligned, the ratio (d ₁ /d ₂ ) of the top surface length d ₁ of the protrusion to the distance d ₂ between the protrusion and an adjacent protrusion is 1.5 to 2.5;
The dash panel according to any one of [1] to [3], wherein the representative length of the protrusion is 4 to 20 mm.
[5] The dash panel according to any one of [1] to [4], characterized in that it is formed from a steel plate having a tensile strength of 590 MPa or more.
[6] A front body structure of an automobile,
[1] to [5], and a dash panel according to any one of [1] to [5].
a front side member attached to the dash panel;
a floor panel joined to the dash panel.

The present invention can be applied to automobile dash panels.

1 Vehicle body front structure 10 Dash panel 11 Front wall 11a First surface portion 11b Second surface portion 11c Third surface portion 12 Bottom wall 12a Inclined surface portion 12b Joint surface portion 13 Wheel arch portion 14 Opening 15 Flange 20 Front side member 21 Front side member mounting surface 30 Floor panel 41 First ridge portion 42 Second ridge portion 43 Third ridge portion 50 Convex portion 51 Convex portion top surface d Length of _convex portion top surface d Spacing between _convex portions A Surface B Surface L Representative length of convex portion S Area of convex portion top surface R Radius of curvature θ of ridge portion Opening angle of ridge portion

Claims (10)

A dash panel for an automobile,
a front wall, a bottom wall, a wheel arch portion, an opening, a flange, and a first ridge portion;
the front wall is a wall portion extending in a vehicle height direction and a vehicle width direction,
the bottom wall is a wall portion extending in the vehicle length direction and the vehicle width direction,
The wheel arch portions are formed at both ends of the dash panel in a vehicle width direction,
The opening is formed in a center portion of the dash panel in a vehicle width direction, from a midpoint in a vehicle height direction to a rear end in a vehicle length direction,
the flanges protrude from the front wall and the bottom wall toward the vehicle interior around the opening,
the first ridge portion is formed continuously around the flange between the front wall and the flange and between the bottom wall and the flange ,
The first ridge portion is a bent portion having a radius of curvature of 25 to 70 mm at the boundary between two adjacent surfaces and an opening angle of the two adjacent surfaces of 145° or less . A second ridge portion and a third ridge portion are provided,
the second ridge line portion is formed continuously between the front wall and the wheel arch portion and between the bottom wall and the wheel arch portion,
2. The dash panel according to claim 1, wherein the third ridge portion extends from the first ridge portion to the second ridge portion. the front wall has a mounting surface to which a front side member is attached,
3. The dash panel according to claim 2, wherein the mounting surface is located between the first ridgeline portion and the second ridgeline portion and above the third ridgeline portion. The dash panel according to claim 3, wherein the mounting surface is a surface perpendicular to a horizontal plane. The dash panel described in any one of claims 1 to 4, characterized in that the front wall has multiple protrusions protruding in a direction perpendicular to the front wall. The dash panel described in claim 5, characterized in that the multiple protrusions are arranged so that the representative lengths of the multiple protrusions are aligned in at least one direction when viewed from a direction perpendicular to the surface on which the protrusions are formed. The dash panel of claim 6, characterized in that the surface coverage of the protrusions, calculated as "total area of the top surfaces of the plurality of protrusions / area of the surface of the front wall on which the plurality of protrusions are formed," is 25% or more. In a cross section perpendicular to the surface on which the protrusions are formed, cut so as to include a direction in which the representative lengths of the plurality of protrusions are aligned, the ratio (d ₁ /d ₂ ) of the top surface length d ₁ of the protrusion to the distance d ₂ between the protrusion and an adjacent protrusion is 1.5 to 2.5,
7. The dash panel according to claim 6, wherein the representative length of the protrusion is 4 to 20 mm. The dash panel described in any one of claims 1 to 4 is formed from a steel plate having a tensile strength of 590 MPa or more. A front body structure of an automobile,
A dash panel according to any one of claims 1 to 4;
a front side member attached to the dash panel;
a floor panel joined to the dash panel.