JP4728899B2 - Automotive hood - Google Patents

Description

  The present invention relates to an automobile hood used by joining an outer panel and an inner panel.

  In recent years, pedestrian protection in automobile accidents has been regulated, and pedestrian protection performance has attracted attention as an index for rating automobile hoods. On the other hand, as the engine increases in size due to the higher output of the engine, the number of parts in the engine room also increases due to the increase in functionality, so the space under the hood necessary for pedestrian protection has also become smaller. Yes. Therefore, in order to achieve both a sporty design and pedestrian protection performance, it is important to develop an automobile hood that can efficiently absorb collision energy in a small space.

  As the automobile hood as described above, Patent Document 1 describes an automobile hood having a hood structure having a cross-sectional structure with a space portion between the two panels when the outer panel and the inner panel are joined. ing.

  An example of an automobile hood having a hood structure similar to the hood structure described in Patent Document 1 is shown in FIGS. As shown in FIGS. 10A to 10C, the automobile hood 101 includes a plurality of outer panels 102 having a predetermined curvature, a frame recess 131 at the periphery, and a parallel arrangement in the vehicle width direction at the center. And the inner panel 103 having the panel plane 132 serving as the bottom of the concave portion formed between the beads 133, the peripheral edge of the outer panel 102, and the inner panel 103. By joining the end portions of the frame recess 131 by hem processing, a cross-sectional structure through the space 104 is taken. Moreover, the panel joining part 133a is arrange | positioned on the upper surface of the bead 133 by predetermined spacing, and the bead 133 and the back surface of the outer panel 102 are adhere | attached through this panel joining part 133a. In addition, although the inner panel of a horizontal bead is shown in FIG. 10, the inner panel in which the bead (vertical bead) was provided in the vertical direction with respect to the vehicle traveling direction is also known (not shown).

In addition, the pedestrian protection performance of an automobile hood is generally evaluated by a head injury value (hereinafter abbreviated as an HIC value). The HIC value is expressed by the following formula ( 1 ) (2. The maximum value of the product of the fifth power and the generation time). And the smaller the HIC value, the better the pedestrian protection performance.

  Here, a is a three-axis combined acceleration at the head center of gravity (unit: G), t1, t2 are times when the HIC value is maximum at time t where 0 <t1 <t2, and calculation time (t2-t1) is It is determined to be 15 msec or less.

  Here, the acceleration when the pedestrian's head collides with the automobile hood is usually the collision acceleration at the time of the primary collision that occurs when the head collides with the automobile hood 101, and then the automobile hood 101. Can be broadly divided into collision acceleration at the time of a secondary collision that occurs in contact with the installation structure in the engine room.

On the other hand, automobile hoods must satisfy the basic performances conventionally required, such as tension rigidity, dent resistance, bending rigidity, and torsional rigidity. Further, in the case of a high-speed collision, it is necessary to bend and deform near the center position in the longitudinal direction of the vehicle body so that the automobile hood does not enter the cabin (automobile). Tension rigidity is necessary to suppress elastic deformation when pushing when waxing or locking the hood for automobiles, and the Young's modulus and thickness of the outer panel, and the joint position of the outer panel and inner panel (In FIGS. 10A to 10C, it is determined by the bonding position of the panel joint portion 133 a). Dent resistance is necessary to suppress plastic deformation remaining due to flying stones, etc., and is affected by the strength and thickness of the outer panel. Bending rigidity is necessary to suppress the elastic deformation of the periphery of the hood for automobiles caused by the pulling force when locking the hood for automobiles and the reaction force of cushion rubber, damper stays, seal rubber, etc. It is influenced by the shape of the inner panel and reinforcement of the peripheral edge (second moment of cross section) and Young's modulus. The torsional rigidity is affected by the bending rigidity at the periphery of the automobile hood and the thickness and shape of the inner panel center.
Japanese Patent No. 3674918

  The automobile hood must satisfy both of these basic performances and pedestrian protection performances, but the space under the automobile hood between the automobile hood and the engine and other structures is limited. In many cases, a hood designed with material, plate thickness, and shape so as to satisfy only basic performance cannot satisfy pedestrian protection performance.

For example, in the conventional automobile hood 101 described above, when the space under the automobile hood 101 is small, the collision acceleration of the secondary collision is larger than the primary collision at the periphery of the automobile hood 101 and continues. Since the time also becomes longer, the collision acceleration of the secondary collision adversely affects the HIC value calculated by the above formula ( 1 ) (that is, the HIC value does not reach a satisfactory level).

  In addition, the inner panel of the vertical bead is generally provided with a structure that acts as an initial fraud, such as a crash bead and a trim hole to make it easier to bend and deform the hood during a high-speed collision. Since the initial fraud reduces the amount of energy absorbed at the time of the primary collision of the pedestrian's head, the collision acceleration at the time of the secondary collision increases to further adversely affect the HIC value.

  As described in Patent Document 1, when a bead is formed in a direction parallel to the width direction of the vehicle, when the head of the pedestrian collides from the front of the vehicle, the position of the pedestrian's head collides. Since it becomes difficult for the bead to be deformed at the time of the secondary collision, the deformation load becomes large and the HIC value may be further deteriorated.

  The present invention has been made in view of the above problems, and even when a bead is formed in a direction parallel to the width direction of the vehicle, a deformation load at the time of a secondary collision when a head or the like collides. An object of the present invention is to provide an automobile hood capable of reducing the size of the vehicle.

  In order to solve the above-mentioned problems, an automobile hood of the present invention has a cross-sectional structure with a space portion between predetermined positions of both panels when the peripheral portions of the outer panel and the inner panel are joined. In the hood, the inner panel includes an inner peripheral edge joined to an outer peripheral edge of the outer panel, a frame recess formed continuously with the inner peripheral edge and forming the space between the outer panel, A plurality of beads provided in a convex shape from the panel plane so that the longitudinal direction is substantially parallel to the width direction of the vehicle at a position that is the center of the panel from the frame recess, and the bead is provided on the outer panel. An upper surface having a panel joint portion to be joined, a front inclined surface that forms a slope over a panel plane ahead of the upper surface with respect to the vehicle traveling direction, A rear inclined surface that forms a slope from the upper surface to the rear panel plane with respect to the direction, an angle θ1 between the front inclined surface and the front panel plane, and the rear inclined surface, The angle θ2 with respect to the rear panel plane is configured to be 155 ° or more.

  The automobile hood of the present invention has an angle θ1 between the front inclined surface and the front panel plane, and an angle θ2 between the rear inclined surface and the rear panel plane, both of which are greater than a specific angle. Since the deformation load (compression force generated on the front inclined surface and / or the rear inclined surface) of the inner panel when the head or the like collides can be reduced, the HIC value can be reduced.

  In the automobile hood according to the present invention, the relationship between the angle θ1 and the angle θ2 preferably satisfies θ1 ≦ θ2.

In the automobile hood of the present invention, by making the relationship between the angle θ1 and the angle θ2 appropriate, the front inclined surface is bent even when the head collides with the front inclined surface from the front obliquely upward direction. It only deforms and can make it difficult to generate a compressive force. That is, since the deformation load of the inner panel can be reduced, the collision acceleration at the time of the secondary collision can be reduced.
In addition, with the automobile hood having such a configuration, when the head collides with the rear inclined surface from the front obliquely upward direction, the bent line on the front inclined surface and the upper surface and the bent line on the rear inclined surface and the upper surface are bent and deformed. The deformation load can be reduced. Therefore, it is possible to reduce the collision acceleration during the secondary collision.

When the vehicle hood according to the present invention draws an orthogonal line orthogonal to the tangent at the center position of the upper surface, the length L1 from the orthogonal line to the panel plane continuous with the front inclined surface, and the orthogonal line It is preferable that the relationship between the rear inclined surface and the length L2 to the continuous panel plane satisfy the following formula ( 2 ).

  By adopting such a configuration, for example, when the head collides with the center position of the upper surface of the bead, the bead is easily deformed evenly, and the deformation load can be further reduced.

In the automobile hood according to the present invention, the length L1 from the above-described orthogonal line to the panel plane continuous with the front inclined surface is set to 15 to 100 mm, and the length from the above-described orthogonal line to the panel plane continuous with the rear inclined surface is set. The length L2 is preferably 25 to 125 mm.
In this way, by defining the length L1 and the length L2 within a specific range, it is possible to reduce the deformation load and ensure an effective stroke to protect this even when the head collides. Can be secured.

In the automobile hood according to the present invention, the bead pitch p is preferably 50 to 200 mm.
By defining the bead pitch p in such a specific range, it is possible to provide an automobile hood that is easy to press-mold while increasing the rigidity of the bead. Moreover, since the adhesion (mastic) between the inner panel and the outer panel is appropriately performed, it is possible to sufficiently secure the tension rigidity.

In the automobile hood according to the present invention, it is preferable that the height h of the bead from the panel plane is 5 to 30 mm.
By defining the height h of the bead from the panel plane within such a specific range, it is possible to provide an automobile hood having high bead rigidity and easy press molding while reducing deformation load.

In the automobile hood according to the present invention, it is preferable that a width dimension Lu of the flat portion of the upper surface of the bead is 5 to 30 mm.
As described above, by defining the width dimension Lu of the flat portion of the upper surface of the bead within such a specific range, the automobile hood of the present invention can more appropriately bond the inner panel and the outer panel (mastic). Therefore, it is possible to sufficiently secure the tension rigidity while reducing the deformation load.

  According to the automobile hood of the present invention, the angle θ1 between the front inclined surface and the front panel plane is formed to be equal to or smaller than the angle θ2 between the rear inclined surface and the rear panel plane. Even when the beads are formed in a direction parallel to the width direction, the beads are easily deformed at the time of a secondary collision when the head or the like collides from an obliquely upward front side, and the deformation load can be reduced. Therefore, the HIC value can be improved.

  Next, the best mode for carrying out the automobile hood according to the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is an exploded perspective view of an automobile hood. FIG. 2 is a perspective view of the inner panel of the automobile hood. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2 and is a diagram for explaining the action when the head collides in the automobile hood of the present invention. FIG. 4 is an enlarged cross-sectional view of a main part of FIG. 2, and is a diagram for explaining an action when the head collides in one aspect of the automobile hood of the present invention. FIG. 5 is a diagram for explaining the relationship between the angles θ1 and θ2, and FIG. 5A is a diagram for explaining a state in which the head collides obliquely from the upper front when θ1 ≦ θ2. FIG. 6B is a diagram illustrating a state in which the head collides obliquely from the upper front when θ1> θ2. FIG. 6 is a graph showing the relationship between the stroke S (mm) and the collision acceleration a (G) when the angles θ1 and θ2 are θ1 ≦ θ2 and θ1> θ2. 7A and 7B are diagrams for explaining the formation angle of the angle θ1, and FIG. 7A is a diagram for explaining a state in which the head collides obliquely from the upper front when θ1 ≧ 155 °. ) Is a diagram illustrating a state in which the head collides from diagonally forward and upward when θ1 <155 °. 8 and 9 are diagrams illustrating the shape of the bead of the automobile hood of the present invention.

  As shown in FIGS. 1 and 2, the automobile hood 1 according to the present invention has a predetermined position of both the panels 2 and 3 when the outer peripheral edge portions 2 a and 3 a of the outer panel 2 and the inner panel 3 are joined. A cross-sectional structure with a space 4 interposed therebetween.

The outer panel 2 has a predetermined curvature (see FIG. 3) and is made of a lightweight and high-tensile metal plate. The metal used for this is preferably steel or a 3000 series, 5000 series, 6000 series or 7000 series aluminum alloy. Further, the plate thickness of the outer panel 2 is preferably 0.5 to 1.1 mm or less for a steel plate and 0.8 to 1.5 mm or less for an aluminum alloy plate, for example. The outer panel 2 may be made of a plate material made of resin or carbon fiber.
The outer panel 2 is joined to the inner peripheral edge 3a of the inner panel 3 described later by fitting, bonding, brazing, etc. by hem processing or the like at the outer peripheral edge 2a. A cross-sectional structure with a space 4 in between is taken.

  The inner panel 3 includes an inner peripheral edge 3 a that is joined to the outer peripheral edge 2 a of the outer panel 2, and a frame recess 31 that is formed continuously with the inner peripheral edge 3 a and forms a space 4 between the inner panel 3. And a plurality of beads 33 provided on the ridge-like ridges from the panel plane 32 so that the longitudinal direction is parallel to the width direction of the vehicle at a position that is the center of the panel from the frame recess 31. .

As shown in FIG. 3, the bead 33 has an upper surface 33 b having a panel joint portion 33 a to be joined to the outer panel 2, and a front slope that forms a slope from the front surface 33 b to the front surface 33 b with respect to the vehicle traveling direction. It has the surface 33c and the back side inclined surface 33d which forms a slope over the panel plane 32 of the rear side rather than the upper surface 33b with respect to the vehicle advancing direction.
3 and 4, the bead 33 includes an angle θ1 between the front inclined surface 33c and the front panel plane 32, and an angle θ2 between the rear inclined surface 33d and the rear panel plane 32. Are formed at 155 ° or more.

The bead 33 is formed so that the relationship between the angle θ1 between the front inclined surface 33c and the front panel plane 32 and the angle θ2 between the rear inclined surface 33d and the rear panel plane 32 satisfies θ1 ≦ θ2. It is preferable to do this.
If the relationship between the angle θ1 and the angle θ2 is θ1> θ2, when the head or the like collides from diagonally forward and upward, a compressive force is generated on the rear inclined surface 33d so that the bead 33 is not easily deformed. It becomes difficult to do.

In this case, the angle θ1 and the angle θ2 preferably satisfy the above relationship, and the angle θ1 is preferably set in the range of 155 to 175 °, and the angle θ2 is also preferably set in the range of 155 to 175 °. .
If the angle θ1 is less than 155 °, the front inclined surface 33c becomes steep, so that, for example, a predetermined angle from the front obliquely upper direction (for example, a line HL parallel to the vehicle traveling direction) near the front inclined surface 33c. When the head (from the direction of α (65 °, 50 °, etc.) collides, a compressive force is generated in the direction of compressing the front inclined surface 33c, so that the bead 33 is not easily deformed and the HIC value is deteriorated. To do. On the other hand, when the angle θ1 exceeds 175 °, it is difficult to secure the height and number of the beads 33, which is not preferable.
Further, when the angle θ2 is less than 155 °, the rear inclined surface 33d becomes abrupt. For example, when the head or the like collides with the vicinity of the rear inclined surface 33d, the rear inclined surface 33d is compressed. Since the compressive force is generated, the bead 33 is hardly deformed, and the HIC value is deteriorated. On the other hand, when the angle θ2 exceeds 175 °, it is difficult to secure the height and number of the beads 33, which is not preferable.

  Further, for example, when an orthogonal line OL orthogonal to the tangent line TL at the center position of the upper surface 33b is drawn, the length L1 from the orthogonal line OL to the panel plane 32 continuing to the front inclined surface 33c, and the orthogonal line described above The length L2 from the OL to the panel plane 32 continuous with the rear inclined surface 33d, the pitch p of the beads 33, the height h of the beads 33, the width dimension Lu of the flat portion of the upper surface 33b of the beads 33, and the like. The shape of the inner panel 3 (see FIGS. 3 and 4) and the plate thickness affect the inertial force generated by the relative speed difference between the head and the automobile hood 1 when the head collides. Therefore, by optimizing the shape and the plate thickness, the acceleration at the time of the primary collision is increased, a sufficient energy absorption amount is ensured, and the pedestrian protection performance of the automobile hood 1 can be improved. .

The automobile hood 1 of the present invention has the above-described length L1 in order to easily deform in the vehicle traveling direction even when the head collides with the bead 33 and to reduce the collision energy at the time of the secondary collision. The relationship with the length L2 preferably satisfies the following formula ( 1 ) (see FIG. 4). If the front inclined surface 33c and the rear inclined surface 33d can be deformed so as to have substantially the same shape when a collision occurs at a predetermined angle α (α is 65 °, 50 °, etc.), the front inclined surface 33c or the rear It becomes difficult to generate a compressive force that compresses in only one direction of the side inclined surface 33d. In this case, the length L1 and the length L2 need only satisfy the relational expression of L2−L1 = 2 · h · tan (90−α−β) in order to be transformed into the same shape. If they are within a certain range that satisfies the equation, they can be deformed so as to have substantially the same shape.

As shown in FIG. 4, the length L1 of the automobile hood 1 of the present invention is preferably 15 to 100 mm, for example, and the length L2 is preferably 25 to 125 mm, for example. .
If the length L1 and the length L2 are less than the appropriate ranges described above, the angle θ1 and the angle θ2 described above often increase, and the front inclined surface 33c and the rear inclined surface 33d are too steep. When a head or the like collides with the vicinity of the front inclined surface 33c or the rear inclined surface 33d, a compressive force is generated in the direction of compressing the front inclined surface 33c or the rear inclined surface 33d, so that the bead 33 is not easily deformed. The HIC value may be deteriorated.
On the other hand, when the length L1 and the length L2 exceed the above-described appropriate range, it is not preferable because it may be difficult to secure the height and the number of the beads 33.

  The length L1 can be, for example, the start portion, the central portion, the end point portion, etc. of the bent portion (R portion) from the front inclined surface 33c in the panel plane 32 continuous from the front inclined surface 33c. Similarly, the length L2 can be a start portion, a center portion, an end point portion, or the like of a bent portion (R portion) from the rear inclined surface 33d in the panel plane 32 continuing from the rear inclined surface 33d. In addition, although the start part, the center part, and the end part of the bent part (R part) can be arbitrarily set, the definitions of the lengths L1 and L2 need to be constant. If the length L1 is defined as “the end portion of the bent portion (R portion) of the panel plane 32 continuous from the front inclined surface 33c”, the other length L2 is “continuous from the rear inclined surface 33d”. It is defined as “the end portion of the bent portion (R portion) of the panel plane 32”.

The pitch p of the beads 33 is preferably 50 to 200 mm. The height h of the bead 33 from the panel plane 32 is preferably 5 to 30 mm.
In any case, if the lower limit value is less than the above-described appropriate range, the rigidity of the bead 33 is insufficient, so that the collision energy cannot be sufficiently absorbed in the primary collision. Therefore, the collision acceleration of the secondary collision increases. On the other hand, if the upper limit value exceeds the above-described appropriate range, not only press molding becomes difficult, but also the bonding pitch between the outer panel 2 and the inner panel 3 is widened, so that the tension rigidity is insufficient.

  Further, the width dimension Lu of the flat portion of the upper surface 33b of the bead 33 is preferably 5 to 30 mm. This is for reliably bonding the outer panel 2 and the inner panel 3 together.

The plate thickness of the inner panel 3 is selected according to the bending rigidity of the outer panel 2 determined by the vehicle type in which the automobile hood 1 is used.
Among these, the appropriate value of the plate thickness in the frame recess 31 of the inner panel 3 is preferably 0.7 to 1.5 mm in the case of an aluminum alloy plate and 0.5 to 1.1 mm in the case of a steel plate. . When the plate thickness is less than the lower limit value, the bending rigidity of the hood 1 for an automobile is likely to be insufficient, and when the plate thickness exceeds the upper limit value, the crushing deformation load increases, so that the pedestrian protection performance is likely to deteriorate. Although it is possible to ensure bending rigidity only by the inner panel 3 and omit reinforcement (not shown), the thickness of the inner panel 3 in this case is a plate further increased than the above. Thickness is preferable, 1.5 to 3.5 mm for an aluminum alloy plate, and 1.1 to 2.5 mm for a steel plate.

  In addition, when producing the inner panel 3 with metals other than an aluminum alloy and steel, it is good to determine the upper limit of the said board thickness in inverse proportion to the specific gravity of the metal to be used.

  The inner panel 3 having such a bead 33 is preferably formed integrally by press molding or the like, but when the shape is complicated, a plurality of members having appropriate shapes are separately manufactured, These may be integrally formed by, for example, mechanical joining joined by hem processing, welding, adhesion by a resin layer, or the like.

  Such an inner panel 3 is preferably made of a light and high-tensile metal plate such as a steel plate or a 3000, 5000, 6000 or 7000 series aluminum alloy plate.

As described above, the main configuration of the automobile hood 1 according to the present invention is as shown in FIGS. 1 to 4, when the outer peripheral edge portions 2a and 3a of the outer panel 2 and the inner panel 3 are joined. The inner panel 3 is provided with a cross-sectional structure with a space 4 between predetermined positions of both the panels 2 and 3, and the inner panel 3 includes an inner peripheral edge 3 a joined to the outer peripheral edge 2 a of the outer panel 2, A frame recess 31 that is formed continuously with the inner peripheral edge 3a and forms a space 4 between the outer panel 2 and the longitudinal direction is parallel to the vehicle width direction at a position that is the panel center from the frame recess 31. And a plurality of beads 33 provided in a convex shape from the panel plane 32, and this bead 33 has an upper surface 33 having a panel joint 33 a that joins the outer panel 2. And a front inclined surface 33c that forms a slope toward the front panel plane 32 from the upper surface 33b with respect to the vehicle traveling direction, and a rear surface that forms the slope toward the panel plane 32 behind the upper surface 33b with respect to the vehicle traveling direction. And an angle θ1 between the front inclined surface 33c and the front panel plane 32 is formed to be equal to or smaller than an angle θ2 between the rear inclined surface 33d and the rear panel plane 32. Yes.
By setting it as the above-described structure, the automobile hood 1 of the present invention improves pedestrian protection performance and secures rigidity as described below.

That is, when the relationship between the angle θ1 and the angle θ2 is made appropriate, the bead 33 is easily deformed when the head collides with the vicinity of the rear inclined surface 33d, which is preferable. 5A, the position of the bead 33 itself is the same as FIG. 5B to be described later, but the angle θ1 is set to be equal to or smaller than the angle θ2 (θ1 ≦ θ2), so that the upper surface 33b is moved to the vehicle. It is provided in front of the traveling direction. On the other hand, in (b), the angle θ1 is increased and the angle θ2 is decreased (θ1> θ2), so that the upper surface 33b is provided rearward with respect to the vehicle traveling direction.
In (a), when the head collides, the rear inclined surface 33d is mainly deformed so as to be displaced forward, so as shown by the solid line in FIG. 6 (θ1 ≦ θ2: the automobile hood according to the present invention). It can be seen that the collision acceleration a (G) in the secondary collision can be reduced by increasing the stroke. On the other hand, in (b), when the head collides at the same position, the rear inclined surface 33d is mainly deformed so as to be further displaced rearward, so that the broken line (θ1> θ2) in FIG. The collision acceleration a (G) in the secondary collision is remarkably increased.

  Further, in the automobile hood 1 of the present invention, for example, when the bead 33 is formed so that the angle θ1 is θ1 ≧ 155 °, if there is a head collision with the bead 33, the bead 33 shown in FIG. The bead 33 is deformed as indicated by the broken line in the left figure. The component of the force acting on the bead 33 at this time is as shown in the right diagram of FIG. That is, when there is an input to the bead 33 at an angle of 65 ° from the horizontal direction, for example, the bead 33 is easily deformed because no compressive force is generated on the front inclined surface 33c of the bead 33.

On the other hand, when the bead 33 is formed so that the angle θ1 is θ1> 155 ° as in the conventional automobile hood 1, if the head 33 collides with the bead 33, FIG. The bead 33 is deformed as indicated by the broken line in the left diagram of FIG. The component of the force acting on the bead 33 at this time is as shown in the right diagram of FIG. That is, when there is an input to the bead 33 at an angle of, for example, 65 ° from the horizontal direction, a compressive force is generated on the front inclined surface 33c of the bead 33, so that the bead 33 is not easily deformed.
Note that FIG. 7 shows a state in which the head collides with approximately the center of the upper surface of the bead 33, but substantially the same result is obtained when the head collides with the vicinity of the front inclined surface 33c.

(Mechanism for securing rigidity)
As shown in FIG. 3 and the like, in the hood 1 for an automobile, the space 4 secures a cross-sectional area of the hood, so that bending rigidity and torsional rigidity required for the hood can be obtained. At the same time, the inner peripheral edge 3a of the inner panel 3 and the outer peripheral edge 2a of the outer panel 2 are joined (adhered), or the inner panel 3 and the outer panel 2 are joined (adhered) at the panel joint 33a. Thus, it is possible to obtain tension rigidity and dent resistance required as a hood.

  As described above, the automobile hood according to the present invention has been described in detail. However, the gist of the present invention is not limited to the above-described contents, and the scope of the right should be broadly interpreted based on the description of the claims. is there. The contents of the present invention can be widely modified and changed as described below based on the above description.

  For example, as described above, the automobile hood 1 of the present invention is preferably provided with the beads 33 so as to be parallel to the width direction of the vehicle. However, the present invention is not limited to this, and the angle of the front inclined surface is not limited thereto. If θ1 is formed to be equal to or smaller than the angle θ2 of the rear inclined surface, the bead 33 may be provided so as to be inclined with respect to the width direction of the vehicle. The bead 33 having such a configuration may be provided by being curved along the outer shape of the inner panel 3 in a plan view.

  Moreover, when a pedestrian collides with the automobile hood 1, the collision area differs depending on whether the pedestrian is a child or an adult. Therefore, as shown in FIG. 2, with respect to the vehicle traveling direction, the front side of the automobile hood 1 is a child collision area CA where a child collides, and the rear side of the automobile hood 1 is an adult collision area AA where an adult collides. Yes.

The automobile hood 1 according to the present invention may be changed in shape as described below between the child collision area CA and the adult collision area AA.
In addition, the shape change to be described later may be formed separately on the front side (child collision area CA) and the rear side (adult collision area AA), and the shape gradually increases from the front end to the rear end. It may be formed so as to change, or may be formed so as to gradually change so that their shapes are connected in the vicinity of the boundary between the front side and the rear side.

  The thickness T (see FIG. 8) of the inner panel 3 is made thin in the child collision area CA and thick in the adult collision area AA. Thus, by changing the plate thickness T, the deformation load is reduced in the child collision area CA of the automobile hood 1 at the time of a head collision. Moreover, in the adult collision area AA of the automobile hood 1, a sufficient amount of energy absorption in the primary collision is ensured.

  The total length W (see FIG. 8) of the hem portion of the bead in a direction parallel to the vehicle traveling direction of the bead 33 is small in the child collision area CA and large in the adult collision area AA. With such a change in the width W, in the case of a head collision, in the adult collision area AA of the hood 1 for an automobile, rigidity is improved and a sufficient amount of energy is absorbed in the primary collision. In addition, the deformation load is reduced on the front side of the automobile hood 1.

  The cross sections R1 and R2 (see FIG. 8) of the bead 33 are made large in the child collision area CA and small in the adult collision area AA. By changing the cross sections R1 and R2, the deformation load is reduced in the child collision area CA of the automobile hood 1 in the case of a head collision. Moreover, in the adult collision area AA of the automobile hood 1, the rigidity is improved and a sufficient amount of energy is absorbed in the primary collision.

  The pitch MP of the panel joint portion 33a in the bead 33 (upper surface 33b) is made smaller on the front side of the automobile hood 1 that requires tension rigidity and dent resistance. The pitch MP may be set so as to gradually change between the front side and the rear side of the automobile hood 1.

  The automobile hood 1 according to the present invention includes a bead 33A (see FIG. 9A) in which a stepped flat portion 33e is formed on a bead inclined surface as a bead 33 of the inner panel 3, and a shelf portion 33f on the bead inclined surface. Alternatively, a bead 33B (see FIG. 9B) in which a recess 35 is formed on the upper surface 33b may be used. In this way, deformation at the time of collision can be promoted. In addition, (a), (b) of FIG. 9 is a figure which shows the other form of the hood for motor vehicles of this invention. The flat portion 33e and the shelf portion 33f may be provided only on the front side or the rear side of the automobile hood 1.

  The hood 1 for an automobile may appropriately change the total length W of the hem portion of the bead 33 in a direction parallel to the vehicle traveling direction of the bead 33 in accordance with the outer shape of the outer panel 2, a design with a step, or the like. Further, the bead 33 may be branched (not shown). Moreover, you may provide an appropriate hole (not shown) in the inner panel 3 for the purpose of attaching a hood silencer, a washer hose, a cushion rubber or the like.

It is a disassembled perspective view of the hood for motor vehicles. It is a perspective view of the inner panel of the hood for motor vehicles. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, and is a diagram illustrating an operation when the head collides in one aspect of the automobile hood of the present invention. It is a principal part expanded sectional view of FIG. 2, and is a figure explaining the effect | action at the time of the head colliding in the one aspect | mode of the hood for motor vehicles of this invention. It is a figure explaining the relationship between the formation angle of the angle (theta) 1 and the angle (theta) 2, Comprising: (a) is a figure explaining a mode that the head collided from diagonally forward upper direction, when (theta) 1 <= theta2. ) Is a diagram illustrating a state in which the head collides obliquely from the upper front when θ1> θ2. It is a graph which shows the relationship between stroke S (mm) and collision acceleration a (G) when the angle θ1 and the angle θ2 are θ1 ≦ θ2 and θ1> θ2. It is a figure explaining the formation angle of angle (theta) 1, Comprising: (a) is a figure explaining a mode that the head collided from front diagonally upward, when (theta) 1> = 155 degrees, (b) is (theta) 1. It is a figure explaining a mode that the head collided from diagonally forward upper direction when it is set to <155 degrees. It is a figure explaining the shape of the bead of the hood for cars of the present invention. It is a figure explaining the shape of the bead of the hood for cars of the present invention. It is a figure which shows an example of the conventional hood for motor vehicles.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automobile hood 2 Outer panel 2a Outer peripheral part 3 Inner panel 3a Inner peripheral part 31 Frame recessed part 32 Panel plane 33, 33A, 33B Bead 33a Panel junction part 33b Upper surface 33c Front side inclined surface 33d Rear side inclined surface 33e Flat part 33f Shelf Portion 35 Recess 4 Spatial portion θ1 Angle between front inclined surface and front panel plane θ2 Angle between rear inclined surface and rear panel plane

Claims (6)

In an automobile hood having a cross-sectional structure with a space portion between predetermined positions of both panels when joining the peripheral portions of the outer panel and the inner panel,
The inner panel is
An inner peripheral edge joined to an outer peripheral edge of the outer panel;
A frame recess formed continuously with the inner peripheral edge and forming the space with the outer panel;
A plurality of beads provided in a convex shape from the panel plane so that the longitudinal direction is substantially parallel to the width direction of the vehicle at a position that becomes the panel central portion from the frame concave portion,
The bead is
An upper surface having a panel bonding portion to be bonded to the outer panel, and a front inclined surface that forms a slope over a panel plane on the front side of the upper surface with respect to the vehicle traveling direction;
A rear inclined surface that forms an inclined surface over a panel plane on the rear side of the upper surface with respect to the vehicle traveling direction,
An angle θ1 between the front inclined surface and the front panel plane and an angle θ2 between the rear inclined surface and the rear panel plane are both formed at 155 ° or more. hood.   The automobile hood according to claim 1, wherein the relationship between the angle θ1 and the angle θ2 satisfies θ1 ≦ θ2. When an orthogonal line perpendicular to the tangent at the center position of the upper surface is drawn,
A length L1 from the orthogonal line to the panel plane continuous with the front inclined surface;
A length L2 from the orthogonal line to a panel plane continuous with the rear inclined surface;
The vehicle hood according to claim 1, wherein the relationship satisfies the following formula (1).

  The automobile hood according to any one of claims 1 to 3, wherein a pitch p of the beads is 50 to 200 mm.   The automobile hood according to any one of claims 1 to 4, wherein a height h of the bead from the panel plane is set to 5 to 30 mm.   The automobile hood according to any one of claims 1 to 5, wherein a width dimension Lu of a flat portion of an upper surface of the bead is set to 5 to 30 mm.

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