JPH07285461A - Upper structure for car body front part - Google Patents

Abstract

PURPOSE:To reduce a head part shock property by efficiently decreasing an HIC value while performing sufficient energy absorption by a limited small deformation stroke. CONSTITUTION:In an upper structure 1 for a car body front part constituted by forming an upper side edge part of a fender in an upper protrusive part 110 by having a vertical wall 101 provided with a step differenced part A and connecting a lower end part of the vertical wall 101 to a hood ridge reinforce 200 provided in a longitudinal direction of a car body in its front both side upper parts, a synthetic resin layer 2 of length corresponding to the length in a car body longitudinal direction of the fender is connected to a reverse surface in the vicinity of the upper protrusive part 110 of the fender. Further, a recessed part 3 is provided in a corresponding location of the synthetic resin layer 2 of the hood ridge reinforce 200.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upper structure of a front part of a vehicle body, and particularly, to reduce a HIC value generated by an impact received by a fender when a head impactor (head impactor) is abutted against an upper edge of the fender. Related to the structure.

[0002]

2. Description of the Related Art As shown in FIGS. 17 and 18, a conventional upper structure of a front portion of a vehicle body has an upper edge portion of a fender 100 having a vertical wall 101 provided with a step portion A and an upper projection portion 110. The joint flanges 102 are formed on the lower end of the vertical wall 101 and are joined to the hood ledge reinforcement 200 provided in the front-rear direction of the vehicle body on the upper portions on both sides of the front portion of the vehicle body. 17 and 18
Reference numeral 201 denotes a hood ledge upper joined to the hood ledge reinforcement 200 and a closed cross-section structure, and reference numeral 30.
Reference numeral 0 denotes a strut housing joined to the closed sectional structure, and reference numeral 400 denotes a hood for opening and closing the engine room.

According to the conventional upper structure of the front part of the vehicle body,
When the head impactor (head impactor) hits the outer surface near the upper protrusion 110 of the fender 100, the stepped portion A of the vertical wall 101 becomes a crushing slash in the initial stage of deformation, so that the fender 100 near the upper protrusion 110 is removed. It is crushed so as to be inverted and deformed so as to project to the side of the hood ledge reinforcement 200, and the inverted portion of the fender 100 contacts the hood ledge reinforcement 200 and is further deformed in the latter stage of the deformation.

As described above, the conventional superstructure of the front part of the vehicle body is
The stepped portion A of the vertical wall 101 causes the fender 10 at the time of collision.
A proper collapse mode of 0 is realized, and this secures the amount of energy absorption required at the time of collision.

[0005]

However, if the energy absorption amount of the fender 100 is secured in this way, the head impact on the fender 100 is not always alleviated.

As experimental data on head impact resistance, WSTC (Wayne State Tolerance Cu) shown in FIG. 19 is used.
rve) is known (“New Edition Automotive Engineering Handbook <Volume 3>” published by the Society of Automotive Engineers of Japan (September 3, 1983)
See page 2-30 of the 1st edition of the 0th edition), and “Safety of automobiles”, Vol. 16 of the Automotive Engineering Bulletin, published by Sankaido Co., Ltd.

The effective acceleration used as a parameter of WSTC is the average acceleration (the integrated value of the acceleration waveform divided by the action time), and when a head impactor (head impactor) collides with the fender 100. Corresponds to the average reaction force that the head impactor receives.

According to this WSTC, even if the average reaction force received by the head is small to some extent (effective acceleration = G1), if the duration becomes long (duration> T1), the dangerous area is reached,
On the other hand, even if the average reaction force is large (effective acceleration = G2), if the duration is extremely short (duration <T2), it can be seen that it does not reach the dangerous area and belongs to the safe area.

That is, the head impact property is determined by both factors of acceleration and action time, and if the energy absorption amount is large, the head impact property is not always alleviated, and the initial reaction force at the time of impact is When the temperature is rapidly increased to a certain extent within a predetermined time, the head impact can be alleviated rather than maintaining the reaction force which is not so high for a long time.

Further, WSTC is experimental data under linear acceleration, and the actual shock received when the head impactor collides with the fender 100 shows a complicated acceleration waveform rather than linear acceleration, and therefore WSTC is directly applied. You cannot do it. Therefore, from the result of the impact test using the impactor,
As a method for evaluating safety based on STC, a method using HIC (Head Injury Criterion), which is one of the obstacle reference values, is known.

The HIC value is obtained by the following derivation formulas (1) and (2).

[Equation 1]

[Equation 2] Is calculated according to. T ₁ and t _{2 in} both equations are 0 <t ₁ <
t ₂ is an arbitrary time during the acceleration action, and a (t)
Is the acceleration at the center of gravity of the impactor's head. The smaller the HIC value, the higher the safety, and generally HIC = 100.
0 is the safety limit.

According to the equation, the HIC value is 2.5 of the average acceleration a ₁₂ in the action time from arbitrary t ₁ to t _2.
It is calculated as the maximum value of the product of the product value and the action time (t ₂ −t ₁ ). That is, if the impact behavior (acceleration waveform) is different, the HIC value is also different in principle, and the average acceleration a ₁₂ and its action time (t ₂ −t ₁ ) are factors that determine the magnitude of the HIC value. Therefore, it cannot be said that the HIC value decreases uniformly even if the amount of impact energy absorbed is large.
There are many cases where the values differ.

Therefore, in the conventional upper structure of the front part of the vehicle body, the average reaction force of the fender 100 at the initial stage of deformation at the time of impact becomes small due to the step portion A of the vertical wall 101, and a long time elapses from the initial stage of deformation. Fender 10 in the later stage of deformation
The average reaction force of 0 may be increased due to further deformation of the hood ledge reinforcement 200 of the reversal portion of the fender 100, and as a result, in order to reduce the head impact, the hood ridge and the fender are overflyed. It was necessary to secure sufficient clearance between departments.

Therefore, according to the present invention, the upper structure of the front part of the vehicle body is capable of sufficiently absorbing energy with a limited small deformation stroke and efficiently reducing the HIC value to reduce the head impact. The purpose is to provide.

[0015]

In order to achieve the above-mentioned object, the invention according to claim 1 is such that the upper edge portion of the fender has a vertical wall provided with a step portion and is formed in the upper protrusion portion, In the upper structure of the front part of the vehicle body, in which the lower ends of the vertical walls are joined to the upper parts on both sides of the front part of the vehicle body to join the hood ledge reinforcements provided in the front-rear direction of the vehicle body, the rear surface near the upper protrusion of the fender In addition, a synthetic resin layer having a length corresponding to the length of the fender in the vehicle body front-rear direction is joined, and a recess is provided at a corresponding portion of the synthetic resin layer of the hood ledge reinforcement. There is.

The invention according to claim 2 is the upper structure of the front part of the vehicle body according to claim 1, wherein the synthetic resin layer is extended and joined in the width direction so as to cover the stepped portion of the vertical wall. It is characterized by being.

The invention according to claim 3 is the upper structure of the front part of the vehicle body according to claim 1, wherein the recess has a width and a depth that allow impact deformation in the vicinity of the upper projection of the fender. It is characterized in that it is formed with.

Further, the invention according to claim 4 is the same as claim 1.
The upper structure of the front part of the vehicle body described above is characterized in that the synthetic resin layer is formed such that a front side of the vehicle body is thin and a rear side of the vehicle body is thick.

[0019]

Since the invention according to claims 1 to 4 has the above-mentioned structure, it has the following effect.

That is, according to the first aspect of the present invention, by providing the synthetic resin layer on the back surface near the upper projection of the fender, the impact input near the upper projection can be performed without disturbing the proper crush mode at the time of impact. This makes it possible to widen the deformation range.

According to the first aspect of the present invention, the deformation stroke of the upper protrusion can be increased by providing the hood ledge reinforcement with a recess.

According to the second aspect of the present invention, the rigidity of the vertical wall can be improved by joining the synthetic resin layer so as to cover the step portion of the vertical wall of the fender.

According to the third aspect of the present invention, the impact is formed by forming the recess provided in the hood ledge reinforcement with a width and a depth that allow impact deformation near the upper protrusion of the fender. The transformation can be completed without bottoming out.

Further, in the invention according to claim 4, the synthetic resin layer is formed such that the front side is thin and the rear side is thick, so that the small impact force input to the front side and the small impact force input to the rear side are input. It is possible to increase the average acceleration of the fender in the initial stage of deformation corresponding to each large impact input.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to illustrated embodiments.

FIG. 1 is a sectional view taken along line XX of FIG. 17, showing an upper structure 1 at the front of the vehicle body as an embodiment.

The upper structure 1 has the same structure as the conventional upper structure of the front portion of the vehicle body described above except that the synthetic resin layer 2 is provided on the fender 100 and the recess 3 is provided on the hood ledge reinforcement 200. Has become. For this reason, the same structural elements will be denoted by the same reference symbols and redundant description will be omitted.

The upper structure 1 has a length corresponding to the length of the fender 100 in the longitudinal direction of the vehicle body on the back surface near the upper protrusion 110 formed by forming the vertical wall 101 on the upper edge of the fender 100. The synthetic resin layer 2 (hatched portion in FIG. 2) is welded, and the recess 3 is provided in the corresponding portion of the synthetic resin layer 2 of the hood ledge reinforcement 200. At this time, the synthetic resin layer 2 includes the corner portion on the rear surface side of the upper protrusion 110 of the fender 100, and the one end portion 2a reaches the upper step portion A ₁ of the step portion A of the vertical wall 101,
The other end portion 2b is welded with a width that reaches the portion of the fender 100 corresponding to the vicinity of the outer end of the flat surface portion 200a of the hood ledge reinforcement 200.

The recess 3 is formed in the plane portion 200a of the hood ledge reinforcement 200 corresponding to the synthetic resin layer 2 in the length direction and the entire length. At this time, the concave portion 3 preferably has the fender 100 as in the present embodiment.
It is formed to have a width and a depth that allow impact deformation near the upper protrusion 110. In FIG. 2, reference numeral 500 indicates
Shows bumper.

The upper structure 1 thus obtained has a structure suitable for reducing head impact.

That is, the upper structure 1 has a waveform approximate to an ideal waveform (average reaction force of fender (F) -deformation stroke of fender (S) waveform) which can effectively reduce the HIC value in the impact experiment. The structure is obtained.

This ideal waveform has a schematic shape of 2 in FIG.
It is obtained by the above-described derivation formulas (1) and (2) based on a basic waveform represented by a dotted chain line a, and a schematic shape is obtained as a solid line b in FIG. 3 by the following impact experiment.

In the impact test, the above-described conventional upper structure of the front part of the vehicle body is used as a basic structure, and an impactor is applied to the upper protrusion 110 of the fender 100 of this upper structure so that the center of gravity of the impactor hits the impactor at that time. This is done by measuring the moving distance and acceleration of. The moving distance and the acceleration of the impactor correspond to the deformation stroke (S) and the average reaction force (F) of the fender 100, respectively, and the impact experiment provides the basic waveform b shown in FIG.

FIGS. 11 to 16 show the impact process by the impactor and the deformation process of the fender 100 in this impact experiment, and the results are as follows when compared with the basic waveform b in FIG.

That is, FIGS. 11 and 12 show a state in which the impactor M is in contact with the upper protrusion 110 of the fender 100,
The upper protrusion 110 is in a non-deformed state, and the position on the basic waveform b at this time is point b ₁ at which the average reaction force (F) and the deformation stroke (S) of the fender 100 are zero.

13 and 14, the impactor M starts to deform the vicinity of the upper protrusion 110 of the fender 100, and the vicinity of the upper protrusion 110 becomes convex toward the plane portion 200a of the hood ledge reinforcement 200. The state in which the tip end of the reversal portion B has abutted against the flat surface portion 200a is shown. The deformation process at this time is indicated by the initial deformation α in FIG. 3, and the time point when the tip of the reversal portion B hits the flat surface portion 200a is indicated by point b ₂ in the basic waveform b. The average reaction force F of the fender 100 at the initial stage α of deformation cannot be obtained because the vertical wall 101 of the fender 100 is easily deformable due to the stepped portion A.

Further, in FIGS. 15 and 16, the impactor M further deforms the vicinity of the upper portion 110 of the fender 100, and at the final stage, the flat portion 200a of the hood ledge reinforcement 200 has the tip of the reversing portion B of the fender 100. The final deformed state of being pressed by and deformed into a concave shape is shown. The deformation process at this time is shown by β in the latter stage of deformation in FIG. 3, and the tip of the reversing portion B is the hood ledge reinforcement 20.
The time point at which the 0 plane portion 200a of 0 is started to be deformed is indicated by b ₃ point, and the final deformation time point is indicated by b ₄ point. Since the deformation in the latter period β of deformation is a bottomed deformation, the average reaction force F of the fender 100 is a peak high average reaction force F at the time point b ₃ when the flat portion 200a of the hood ledge reinforcement 200 starts to be deformed. Then, after the point b ₃ has passed, it drops sharply and becomes 0 at the final deformation point b ₄ . In this way, the basic waveform b is obtained.

At this time, the energy absorption amount of the basic structure corresponds to the area divided by the basic waveform b shown in FIG. 3 and the horizontal axis showing the deformation stroke S of the fender.

The ideal waveform a has the same energy absorption amount as that of the basic structure described above, and the above-described derivation formulas (1) and (2) are used so that the HIC value becomes lower than that of the basic structure. Obtained by calculation.

As shown by the chain double-dashed line in FIG. 3, the ideal waveform a has a higher average reaction force F of the fender than the basic waveform b with a peak a ₁ at the initial stage α of deformation and a later stage β of deformation. At the shoulder portion a ₂ which gradually decreases, and the fender deformation stroke S becomes long with an increase ΔS of the deformation stroke.

This ideal waveform a suggests how the design of the basic structure can be changed to obtain the upper structure of the front part of the vehicle body suitable for reducing the head impact in a small clearance. The upper structure 1 of this embodiment is constructed based on this design concept.

As described above, the upper structure 1 is provided with the synthetic resin layer 2 for increasing the average reaction force F at the initial stage α of deformation, and the average reaction force at the latter stage β of deformation as well as the conventional upper structure as the basic structure. It is configured by providing a concave portion 3 for decreasing F and increasing the deformation stroke of the fender. With this configuration, the upper structure 1 can exhibit a waveform similar to the ideal waveform a.

The upper structure 1 is deformed through the deformation process shown in FIGS. 4 to 9 in the same impact test as when the basic waveform b is obtained.

In FIGS. 4 and 5, the impactor M is the fender 100.
The upper protrusion 110 is in a non-deformed state in which the upper protrusion 110 is in contact with the upper protrusion 110. In this state, the average reaction force F and the deformation stroke S of the fender 100 are 0, which corresponds to point b ₁ shown in FIG.

6 and 7 show a state in the initial stage of deformation in which the vicinity of the upper protrusion 110 of the fender 100 starts to be deformed by the impactor M, and the vicinity of the upper protrusion 110 is the stepped portion A of the vertical wall 101. It is in a state of being inverted and deformed so as to be convex toward the flat surface portion 200a side of the hood ledge reinforcement 200 without inhibiting an appropriate crush mode. The inverted portion C at this time is obtained as a result of the synthetic resin layer 2 being welded so that a wider range than the inverted portion B in the basic structure is deformed as shown in FIG. Therefore, the upper structure 1 can obtain a higher average reaction force F than the basic structure, and as shown in FIG. 3, the ideal waveform a ₁ having the peak a ₁ at the initial deformation α is obtained.
It is possible to produce a waveform close to.

8 and 9, the impactor M further deforms the vicinity of the upper protrusion 110 of the fender 100,
The final point of deformation when the reversal portion C enters the inside of the recess 3 and is deformed is shown. This latter stage of deformation is a deformation process that does not bottom out. Therefore, the upper structure 1 can obtain a lower average reaction force F than the basic structure and can increase the deformation stroke S, has the shoulder portion a ₂ in the latter period β of deformation as shown in FIG. 3, and A waveform similar to the ideal waveform a having the increased deformation stroke ΔS can be produced.

Thus, the upper structure 1 can exhibit a waveform similar to the ideal waveform a, and has a structure suitable for reducing the head impact property due to the reduction of the HIC value.

FIG. 10 shows an upper structure 10 at the front of the vehicle body as another embodiment. The upper structure 10 differs from the upper structure 1 described above in that the synthetic resin layer 2 is extended and welded in the width direction so as to cover the step portion A provided on the vertical wall 101 of the fender 100. It is the same.

That is, the synthetic resin layer 2 in the upper structure 10 is extended so that one end portion 2a in the width direction thereof reaches the lower step portion A ₂ of the step portion A and is welded so as to cover the step portion A.

The superstructure 10 thus constructed can improve the rigidity of the vertical wall 101 without impairing the proper collapse mode, and as a result, the average reaction force F of the fender 100 at the initial stage of deformation is further increased. As a result, a waveform more similar to the ideal waveform a can be produced. Superstructure 10
The waveform at the latter stage of deformation in the above is similar to that of the upper structure 1 due to the recess 3.

Therefore, the upper structure 10 has a structure suitable for reducing the head impact property due to the decrease in the HIC value.

Next, a modification of the present invention will be shown. The synthetic resin layer 2 welded to the upper structures 1 and 10 at the front of the vehicle body can be formed such that the front side of the vehicle body is thin and the rear side of the vehicle body is thick. By forming the synthetic resin layer 2 by changing the thickness of the vehicle body in the front-rear direction in this manner, the initial stage of deformation corresponding to the small impact force input to the front side and the large impact force input to the rear side, respectively. The average reaction force of the fender 100 can be increased.

For example, a small impact force is obtained by a small impact, a large impact force is obtained by an adult, and it is possible to reduce the head impact property by decreasing the HIC value of each.

[0054]

As described in detail above, the present invention has the following effects.

That is, according to the invention of claim 1,
By providing the synthetic resin layer on the back surface near the upper protrusion of the fender, it is possible to widen the deformation range due to the impact input near the upper protrusion without hindering the proper crush mode at the time of impact. It is possible to increase the average reaction force of the fender in the initial stage of deformation when the deformation stroke starts.

According to the first aspect of the invention, the recess is provided in the hood ledge reinforcement.
The deformation stroke in the vicinity of the upper protrusion can be increased, and as a result, the average reaction force of the fender in the latter stage of deformation at which the deformation stroke ends can be suppressed, and in addition to the appropriate crush mode described above, it is limited to a small amount. The deformation stroke can sufficiently absorb energy.

Therefore, according to the first aspect of the present invention, the HIC value is efficiently increased by the increased average reaction force of the fender in the initial stage of deformation, the suppressed average reaction force of the fender in the latter stage of deformation, and the increased deformation stroke. It is possible to obtain an average reaction force-deformation stroke waveform that is close to an ideal waveform that can be reduced to 1. Therefore, it is possible to provide a superstructure of the front part of the vehicle body suitable for reducing head impact.

According to the second aspect of the present invention, by fusing the synthetic resin layer so as to cover the step portion of the vertical wall of the fender, the rigidity of the vertical wall can be improved, and as a result, the fender in the initial stage of deformation. The average reaction force-deformation stroke waveform can be obtained, which is further approximated to the ideal waveform that can effectively lower the HIC value by further increasing the average reaction force. A suitable front superstructure can be provided.

According to the third aspect of the present invention, the recess formed in the hood ledge reinforcement is formed to have a width and a depth that allow the impact deformation in the vicinity of the upper protrusion of the fender. Can be ended without bottoming out, so that it is possible to efficiently achieve suppression of the average reaction force in the latter stage of deformation and sufficient energy absorption due to an increase in deformation stroke, which results in head impactability. It is possible to provide an upper structure of the front part of the vehicle body suitable for reducing

Further, in the invention according to claim 4, the synthetic resin layer is formed such that the front side is thin and the rear side is thick, so that the small impact force input to the front side and the small impact force input to the rear side are input. It is possible to increase the average reaction force of the fender at the initial stage of deformation corresponding to each large impact input, so it is possible to reduce the impact on the head according to the size of the impacted body. Can provide a superstructure of.

[Brief description of drawings]

FIG. 1 is a view of an upper structure of a front part of a vehicle body as an example.
It is a sectional view corresponding to line XX of FIG.

FIG. 2 is a plan view of one side half of the upper structure of the vehicle body front portion of FIG. 1 in the vehicle width direction.

FIG. 3 is a diagram showing an ideal waveform and a basic waveform of an average reaction force-deformation stroke of a fender related to the upper structure of the front part of the vehicle body of FIG.

FIG. 4 is an explanatory diagram showing an impact process in an impact experiment of the upper structure of the front portion of the vehicle body shown in FIG.

5 is a deformation state diagram of the fender in an impact test of the upper structure of the front part of the vehicle body of FIG.

FIG. 6 is an explanatory diagram showing a shock process in a shock experiment of the upper structure of the front part of the vehicle body of FIG.

7 is a deformation state diagram of the fender in an impact test of the upper structure of the vehicle body front portion of FIG.

FIG. 8 is an explanatory diagram showing a shock process in a shock test of the upper structure of the vehicle body front portion of FIG. 1.

9 is a deformation state diagram of the fender in an impact test of the upper structure of the front part of the vehicle body of FIG.

FIG. 10 is a cross-sectional view of the upper structure of the front portion of the vehicle body as another embodiment corresponding to line XX in FIG.

FIG. 11 is an explanatory diagram showing an impact process in an impact experiment for obtaining a basic waveform related to the upper structure of the front part of the vehicle body in FIG.

12 is a deformation state diagram of a fender in an impact test for obtaining a basic waveform related to the upper structure of the front part of the vehicle body in FIG.

13 is an explanatory diagram showing an impact process in an impact experiment for obtaining a basic waveform related to the upper structure of the front part of the vehicle body in FIG.

FIG. 14 is a deformation state diagram of the fender in an impact test for obtaining a basic waveform related to the upper structure of the front portion of the vehicle body in FIG.

15 is an explanatory diagram showing a shock process in a shock test for obtaining a basic waveform related to the upper structure of the front part of the vehicle body in FIG.

16 is a deformation state diagram of the fender in an impact test for obtaining a basic waveform related to the upper structure of the front part of the vehicle body in FIG.

FIG. 17 is a perspective view of the vehicle body showing a portion of an upper structure of a vehicle body front portion.

FIG. 18: XX of FIG. 17 of the conventional superstructure of the front part of the vehicle body
It is sectional drawing which follows the line.

FIG. 19 is a WSTC diagram.

[Explanation of symbols]

 1, 10 Upper structure of front part of vehicle body 2 Synthetic resin layer 3 Recessed portion 100 Fender 101 Vertical wall (of fender) 110 Upper protrusion (of fender) 200 Hood ledge reinforcement 200a Flat portion (of hood ledge reinforcement) A Stepped portion (Of the vertical wall)

Claims (4)

[Claims] 1. An upper edge portion of the fender has a vertical wall provided with a step portion and is formed in an upper protrusion, and lower end portions of the vertical wall are provided on upper portions on both sides of a front portion of the vehicle body. In the upper structure of the front part of the vehicle body joined to the hood ledge reinforcement provided in the direction, a synthetic resin layer having a length corresponding to the length of the fender in the vehicle body front-rear direction is provided on the back surface near the upper protrusion of the fender. Are joined together, and a recess is provided at a corresponding portion of the synthetic resin layer of the hood ledge reinforcement, and an upper structure of a front portion of a vehicle body. 2. The upper structure of the front portion of the vehicle body according to claim 1, wherein the synthetic resin layer is extended and joined in the width direction so as to cover the stepped portion of the vertical wall. Superstructure on the front of the vehicle. 3. The upper structure of the front part of the vehicle body according to claim 1, wherein the recess is formed to have a width and a depth that allow impact deformation in the vicinity of the upper protrusion of the fender. The superstructure of the front part of the vehicle body. 4. The vehicle upper structure according to claim 1, wherein the synthetic resin layer is formed such that the front side of the vehicle body is thin and the rear side of the vehicle body is thick. Front superstructure.