JP4240485B2 - Car cowl structure - Google Patents

Description

  According to the present invention, a flat dash upper panel that forms a cowl rear wall and supports a lower end portion of a windshield at an upper end portion thereof has a rectangular opening extending in the vehicle width direction and has the same depth from the opening surface. In particular, the present invention relates to a cowl structure of an automobile provided with a bent portion with a cross-sectionally U-shape and an inclined bottom surface formed on an upper side and a lower side extending in a vehicle width direction by projecting obliquely to either the front or rear of the vehicle. .

As a damaged portion of the head at the time of a collision with a pedestrian, there is a dashboard area in addition to a hood, a fender and the like. According to Patent Document 1, in the windshield support structure in which the support of the windshield is extended from the upper part of the dashboard and the lower side of the windshield is supported by this support, the bent portion of the substantially V-shaped cross section extended from the dashboard; A windshield support structure is known in which a box portion having a hollow rectangular cross section and a flange portion that receives a windshield are formed, and the box portion is a cantilevered support disposed sufficiently away from the upper portion of the dashboard. According to Patent Document 2, as a conventional technology of the invention, the lower end of the windshield is supported by a cowl top garnish attached to the front bulkhead, that is, a cowl louver panel. It is also well known that the dash upper panel has a dogleg-shaped bend.
JP-A-11-321709 JP 2002-46649 A

  However, as shown in FIG. 6, for example, as shown in FIG. 6, a shock absorbing structure for reducing HIC (Head Injury Criterion, head damage value) is welded between the cowl top side inners on both sides, and A flat dash upper panel 30 that supports the lower end portion of the windshield with the rear end portion of the cowl louver panel 36 is formed with a bent portion 31 having a cross-sectional shape and a flat end portion on both sides thereof. When closed by the closing surface 33, the strength is locally increased in the end region. This increase in the bending strength is not affected by the bent portion terminating at the position close to the front pillar, but the air supply duct opening 35 may be provided in the middle of the dash upper panel 30 in the vehicle width direction. In addition to increasing the bending strength of the region, the strength of the intermediate region is further increased by the adjacent closing surface 33. Conventionally, no connection structure has been proposed between such a bent portion and a part in the middle region.

  In view of such a point, the present invention can suppress that the bending strength of the side end region is locally increased due to the presence of the closing surface at the side end of the bent portion having a cross-sectional shape. The object is to provide a car cowl structure of the kind mentioned at the beginning.

  In order to achieve this object, according to the present invention, a flat dash upper panel that forms a cowl rear wall of a box-shaped cowl portion and supports a lower end portion of a windshield at an upper end portion is provided in the vehicle width direction. A bent portion having a cross-sectional shape formed in a rectangular opening extending to the same, and the bent portion has the same depth from the opening surface of the opening to either the vehicle front or the vehicle rear, In addition, in the cowl structure of an automobile that is formed with an inclined bottom surface on the upper side and the lower side that extend obliquely and extend in the vehicle width direction, the bent portion body having a cross-sectional shape is continuously connected to the upper and lower peripheral edges of the opening portion. A bent side portion formed in a side opening portion having a side edge that extends in a curved shape in the vehicle width direction is extended, and the bent side portion includes a fold between the upper and lower inclined bottom surfaces. Side part circumference in the vehicle width direction following the bending line A curved side bottom surface is formed on the upper and lower sides of the side folding line extended to the side, and the side edge is opposed to the folding line with the width between the upper and lower edges as a short axis. It is formed in a semi-elliptical shape whose major axis is at least twice the relatively long distance from the bent plane view line on the opening surface to the upper and lower peripheral edges, and the side folding line is in the vehicle width direction. Formed in a substantially elliptical shape with the major axis being twice the distance to the intersection with the side edge of the folded planar view line extended to the long axis and the minor axis being twice the depth of the folding line, The upper and lower side bottom surfaces are displaced in the depth direction, with the short axis being twice the distance from the bent plane view line displaced in the depth direction to the upper and lower inclined bottom surface portions, respectively. The long axis is twice the distance to the intersection with the side fold line of the folded plane view line extending in the vehicle width direction. Rukoto by, characterized in that it is set by a set of substantially 1/4 ellipse determined each time displacing the folding plan view line in the depth direction.

  The side edge is smoothly continuous with the upper and lower edges of the opening in a substantially semi-elliptical shape. In addition, the major axis corresponds to the relatively wide vertical width of the inclined bottom surface, and the side bottom surface is formed in a substantially ¼ ellipse shape that smoothly continues to the upper and lower inclined bottom surfaces. The bent portion bends according to the impact force including not only the bent portion main body having a cross-sectional shape but also the upper and lower side bottom surfaces of the bent side portion. The long axis can be set to be appropriately long in the vehicle width direction.

  In the case where the major axis and the minor axis of the ellipse have the same length, according to claim 2, the distance from the bent plane view line to the upper and lower peripheral edges is equal, and the side peripheral edge is formed in a substantially semicircular shape. Or the depth of the folding line is equal to the distance from the folding planar view line to the upper and lower peripheral edges, so that the side bottom surface is formed in a substantially 1/4 spherical shape. The

  According to claim 4, as a connecting structure between a part and a bent part provided in the dash upper panel, a part for increasing the bending strength is provided in the dash upper panel, and a bent side part is formed in the adjacent region. Is done.

  According to the first aspect of the present invention, the bent portion of the U-shape returns to the general surface of the dash upper panel via the bent side portion of the elliptical curved surface that is smoothly continuous and has a sufficient extension amount. As a result, the bending strength gradually changes in the vehicle width direction and asymptotically approaches the bending strength of the general surface, and it is avoided that the shock absorption stroke is locally excessively small at the side end portion of the bending portion. Asymptotically approaches the shock absorption stroke. At that time, depending on the shape of the dogleg shape, the side edge is formed into a semicircular shape according to the invention of claim 2, and the side bottom surface is formed into a 1/4 spherical shape according to the invention of claim 3. According to the invention of claim 4, when a component that increases the bending strength such as an air duct opening is provided in the dash upper panel, the bent portion is connected to the component through such a bent side portion. It is avoided that the bending strength further increases in the adjacent region.

  The structure of the cowl portion of the automobile according to the embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 4, the cowl portion 4 has a cowl top outer front panel 5 connected to a dash upper panel 11, which is an upper portion of a steel-made dash panel 10, via a dash front panel 12, and a cowl at the tip thereof. A louver panel 6 is joined to form a box having a cavity 6a. Each of these parts is connected to the cowl top side inner 3 which is attached between the front pillar 8 and the front suspension tower 7 and closes the end face of the cavity 6a. Between the glass support plate 13 welded to the upper end portion of the dash upper panel 11 and the rear end portion of the cowl louver panel 6, the front glass 9 attached to the front pillar 8 on both sides and the opening surrounded by the roof is sandwiched.・ Supported in an adhesive state.

  Such a cowl louver panel 6 is closed at both ends by a cowl top side inner 3 on a dash upper panel 11 as a cowl rear wall of a box-shaped cowl portion 4 that forms part of an upper wall and a front wall. A duct opening 28 (FIG. 1) to which the air supply duct is connected is provided on the side, and a bent portion 20 is formed in the vehicle width direction in the remaining area so as to absorb the impact applied from the windshield 9 side. ing. Further, the impact applied to the rear end portion of the hood at the time of a collision accident is absorbed by the deformation of the cowl top outer front panel 5 or the cowl louver panel 6 that forms the cavity 6a.

  As shown in FIGS. 1 and 2, the bent portion 20 has a rectangular opening 29 having upper and lower peripheral edges 21 and 21a extending at equal intervals in the vehicle width direction and having the same depth from the opening surface 29A. a bent portion main body 20a in which inclined bottom surfaces 26 and 26a are formed in a cross-sectionally U-shape on the upper and lower sides of a bending line L1 extending forward in the vehicle width direction at c, and upper and lower peripheral edges 21 and 21a. A side opening 29a having a curved side periphery 24 continuously extended in the vehicle width direction is continuously extended in the vehicle width direction continuously from the inclined bottom surfaces 26 and 26a and is continuous to the folding line L1. And the bent side portion 20b on which the upper and lower curved side bottom surfaces 25, 25a of the side bending line L2 extending in the vehicle width direction up to the side edge 24 are formed. It is configured.

  The bending portion main body 20a has a bending strength that supports the windshield 9 in a normal state on the assumption that the depth c is assumed in consideration of avoiding interference with the components arranged in the cavity 6a and bending strength. It is configured to be relatively longer than the distance b so as to be able to bend with respect to an impact load assumed when the head hits the windshield 9 of the pedestrian who is secured and flipped up.

As shown in FIG. 3, the side edge 24 of the side opening 29a is bent in accordance with the following equation (1), with the half width d between the upper and lower edges 21 and 21a being the short axis as the short axis. the surface directly opposite semi-elliptical shape twice the distance a from plan view lines X ₀ flexural Ori is the projection line on the opening surface 29A to a relatively long rim 21 and the long axis to the line L1, the boundary It is formed so as to be continuous without causing a bending point. That is, in equation (1), e = a, d = (a + b) / 2.
x ² / e ² + y ² / d ² = 1 (1)

Side folding line L2, the distance f to the intersection α between the bent side rim 24 in plan view lines X ₁ obtained by extending the folding plan view lines X ₀ in the vehicle width direction on the side opening surface 29B It is formed in a quarter ellipse having a major axis of 2 times and a minor axis of 2 times the depth c of the folding line L1. That is, the side folding line L2 is smoothly continuous like the side edge 24 so that a bending point is not formed in the folding line L1 due to the elliptical shape.
x ′ ² / f ² + z ² / c ² = 1 (2)

Curves of the side bottom surfaces 25 and 25a on the opening surface along the opening surface 29B at a depth g obtained by displacing the folded planar view lines X ₀ and X ₁ in the depth direction perpendicular to the opening surface 29A are If the distances to the inclined bottom surfaces 26 and 26a corresponding to the length g are i and j and the distance to the intersection β with the side bending line L2 is h, h in accordance with the equations (2) and (3) The major axis is set to 2 times, and the minor axis is set to 2 times i and j. Thus, the curved shape of the side bottom 25,25a is set by a set of quarter elliptic required each time be displaced in extended folding deep bending plan view lines X ₁ direction, in fact deep For example, a quarter ellipse is calculated by dividing the length into ten, and a curved surface is set by a set of substantially ellipses between them by an approximate calculation process. The curved surface shapes according to the formulas (1) to (4) described above are applied to the bent side portions 20b on both sides, but the bent side portions 20b on the side adjacent to the front pillar 8 are slightly different from the dash upper panel 11. It is formed so as to have a substantially semi-elliptical side edge 24 that approximates a semi-elliptical shape and a substantially quarter-elliptical side bottom surface 25, 25a in accordance with a backward curve.
^{x 2 / h 2 + y '} 2 / i 2 = 1 ...... (3)
x ² / h ² + y ′ ² / j ² = 1 (4)

  In the bent side portion 20b described above, the major axis of the semi-elliptical side opening portion 29a is set corresponding to the longer one of the rotation radii centered on the bending line L1 of the inclined bottom surfaces 26 and 26a. As a result, the upper and lower inclined bottom surfaces 26, 26a and the ellipse-assembled side portion bottom surface 25a are bent to an extent corresponding to the impact force, and therefore the bending strength gradually increases in the vehicle width direction via the bent side portion 20b. As a result, it gradually approaches the bending strength of the flat general surface 11a of the dash upper panel 11.

  The operation of the cowl having such a structure is as follows. When the pedestrian's head that is bounced up by the collision collides with the windshield 9 with a large impact force (see FIG. 2A), the impact load follows the breakage and the impact load is applied to the upper end of the dash upper panel 11. When applied to the lower end, the inclined bottom surface 26, 26a of the bent portion main body 20a or the side bottom surface 25, 25a of the bent side portion 20b is folded with respect to each other with the folding line L1 or the side bent line L2 as a fulcrum. Bends to fold and absorb impact. At that time, the side bottom surfaces 25 and 25a have a sufficient width in the vehicle width direction and are substantially elliptical and continuous without causing a bending point. Absorbed. Further, although the shock absorption stroke varies depending on the impact location with respect to a predetermined impact force, the bending side portion 20b gradually increases the shock absorption stroke of the general surface 11a toward the outside of the passenger compartment without sharply increasing the bending strength. Get closer to. Incidentally, when the bottom surface of the bent side portion is formed with upper and lower flat inclined triangles, a bending point is generated at the boundary line with the bent portion main body 20a, and the inclined surfaces 26, 26a or the bent portions of the bent portion main body 20a corresponding to the impact force are generated. It becomes difficult to bend the side bottom of the side.

  Further, even when a collision with the region of the duct opening 28 having a relatively large bending strength occurs, the bending side portion 20b gradually terminates near the general surface 11a in the vicinity thereof, so that the bending strength is increased. It is avoided that the height is higher than the duct opening 25 itself. On the opposite side, the impact can be absorbed according to the curved bent shape of the bent side portion 20b up to the closest position of the front pillar 8.

  In addition, in order to make the bending strength of the bent side portion 20b asymptotic to the general surface 11a more gradual, it may be formed in a substantially semi-elliptical shape in which the major axis is further extended as e> a in the above-described formula (1). Conceivable. Further, in the above formula, when the bending strength is set as a = b = c, the peripheral edge of the side opening can be substantially semicircular, and the bent side can be formed into a substantially 1/4 spherical shape. . Furthermore, depending on conditions such as the arrangement of parts in the cavity 6a, the same action can be obtained by projecting the bent portion main body backward as shown in FIG. 5 and the bent side portion correspondingly projecting backward in a curved shape. It is also possible to obtain an effect.

It is a perspective view of the cowl part which provided the bending part in the rear wall which abbreviate | omitted the cowl top side inner part of the motor vehicle by embodiment of this invention. A sectional view of the cowl portion is shown. FIG. A is a sectional view taken along line AA in FIG. 1, and FIG. B is a sectional view taken along line BB. It is a figure explaining the setting method of the curved surface shape of the bending side part of the bending part. It is a perspective view of the vehicle front part containing the cowl part. It is sectional drawing of the cowl part by another embodiment of this invention. It is a perspective view of the conventional cowl part which provided the bending part in the dash upper panel.

Explanation of symbols

6 Cowl louver panel 6a Cavity 9 Windshield 10 Dash panel 11 Dash upper panel 11a Flat general surface of dash upper panel
20 bent portion 20a bent portion main body 20b bent side portion 21, 21a peripheral edge 24 side peripheral edge 28 duct opening 25, 25a side bottom surface 26, 26a inclined bottom surface 29 rectangular opening 29A opening surface 29B side opening surface L1 bending Line L2 Side Bending Line X ₀ Fold Plan View Line X ₁ Extended Fold Plan View Line

Claims (4)

A flat dash upper panel, which forms the cowl rear wall of the box-shaped cowl and supports the lower end of the windshield at the upper end, is formed in a rectangular opening extending in the vehicle width direction. The bent portions have the same depth from the opening surface of the opening portion to either the vehicle front side or the vehicle rear side and extend obliquely and extend in the vehicle width direction on the upper side and the lower side. In the cowl structure of an automobile formed by an inclined bottom surface,
A bent side portion formed in a side opening portion having a side periphery that extends in a curved shape in the vehicle width direction is extended to the bent portion main body having a cross-sectional shape in a cross section and extending continuously in the vehicle width direction. In addition, the bent side portion has curved surfaces on the upper side and the lower side of the side bending line that extends to the peripheral edge of the side portion in the vehicle width direction continuously to the bending line between the upper and lower inclined bottom surfaces. Shaped side bottoms are formed,
The side periphery is a relative distance of the distance from the folded planar view line on the opening surface facing the folding line to the upper and lower circumferential edges, with the width between the upper and lower circumferential edges as a short axis. Formed in a substantially semi-elliptical shape with the long axis as at least twice the long distance,
The side folding line has a major axis that is twice the distance to the intersection with the side edge of the folded plane view line that extends in the vehicle width direction, and doubles the depth of the folding line. It is formed in an approximately ¼ ellipse with a short axis,
The upper and lower side bottom surfaces have a minor axis that is twice the distance from the folded planar view line displaced in the depth direction to the upper and lower inclined bottom surface portions, respectively. The folding plane view line is moved in the depth direction by setting the major axis to twice the distance to the intersection with the side folding line of the folded plane view line that has been displaced and extended in the vehicle width direction. A cowl structure for an automobile, which is set by a set of approximately ¼ ellipses obtained each time the displacement is made.   2. A cowl structure for an automobile according to claim 1, wherein the distance from the bent plane view line to the upper and lower rims is equal, and the side rim is formed in a substantially semicircular shape.   The depth of the folding line is equal to the distance from the folding plane view line to the upper and lower rims, respectively, so that the side bottom surface is formed in a substantially 1/4 spherical shape. 2. The cowl structure of an automobile according to 2.   The automobile according to any one of claims 1 to 3, wherein the dash upper panel is provided with a part for increasing the bending strength, and a bent side portion is formed in an adjacent area. Cowl structure.

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