KR0181692B1 - Fender structure of automotive vehicle - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fender structure of a motor vehicle, which is bent at an upper protrusion 1110, and has a fender panel 1100 having a vertical wall 1101 on which a step FA is formed so as to be easily broken. It has a reinforcement layer disposed on the vertical wall of the fender to absorb the impact applied to the fender, and a hood ridge reinforcement member 1200 for stopping the deformed reinforcement layer, the impact energy absorption rate of the reinforcement layer is the shortest of the fender panel In order to effectively reduce the head impact criterion in the stroke, the impact energy generated during the collision is determined to be absorbed according to the ideal shock energy absorption waveform. It relates to a fender structure.

Description

Fender Structure of Car

The present invention relates to a front upper structure of a vehicle, and in particular, when the vehicle collides with a pedestrian, the impact energy applied to the front upper body of the vehicle can be effectively absorbed by the head of the pedestrian (in the case of an impact test). It relates to a front upper side (eg hood and fender) structure of a motor vehicle.

An example of this kind of hood structure is shown in Japanese Laid-Open Patent Application No. 61-26682.

As shown in FIG. 1A, in this conventional hood structure, the inner panel 7 is attached to the inner side (side of the engine room 5) of the hood outer panel 3 of the hood 1. The inner panel 7 is composed of a frame 9 and an inner rib 11 formed on the inner side of the frame 9 to reinforce the frame 9. The frame body 9 is pivotally supported on the vehicle body via two hood hinges 13 attached to both rear sides of the frame body 9.

Further, as shown in FIG. 1B, a flat plate portion 17 is formed between two inner ribs 11 positioned on the engine 15, and the flat plate portion 17 has a plurality of punched protrusions 19. ) (Formed so that the flat plate 17 is cut out with a punch so that the curved piece 19 can protrude toward the lower engine side). As shown in FIG. 1C, the cross-sectional shape of each punching protruding piece 19 is formed in a substantially circular arc shape, and both ends thereof are connected to the flat plate portion 17. As shown in FIG.

In the hood structure as described above, when the head of the pedestrian collides with the outer surface of the hood outer panel 3, the hood outer panel 3 and the inner rib 11 are deformed into the engine room 5, The punch machining protrusion 19 also collides with the engine 15 and is deformed by compression. Therefore, the impact energy applied to the hood 1 on the engine 15 can be absorbed by reducing the moving distance (hereinafter referred to as 'stroke') of the hood 1 due to the deformation of the punching protrusion 19. .

However, as described above, even when the impact energy is absorbed by the hood 1, the impact energy applied to the head of the pedestrian may not necessarily be safely reduced in practice.

As experimental data on the impact characteristics of the head, the WSTC (Wayne State Tolerance Curve) shown in FIG. 2 is well known so far, which is produced by the New Automotive Vehicle Engineering Manual issued by the Japan Automotive Technology Association on September 30, 1983. 3rd edition], pages 2-30 and 201-203 of [Automotive Vehicle Engineering Encyclopedia, Vol. 16] published by Sankaido Inc. on March 20, 1980.

In this WSTC, effective acceleration (G) is used as a variable. This effective acceleration G is the average acceleration obtained by dividing the integral value of the acceleration by the time (ms). Therefore, the effective acceleration corresponds to the average effort taken by the head of the pedestrian in the event of a collision.

The WSTC shown in FIG. 2 has a small average action force (e.g. effective acceleration = G1) received by the head impactor (the head of a pedestrian in the case of a stratification) and a long time (e.g., Even at time T1), the impact energy applied to the head bombardment reaches the danger zone. On the other hand, even if the average working force received by the head impactor (pedestrian's head) is somewhat large (e.g. effective acceleration = G2) and the time is extremely short (e.g., time T2), the impact energy is in the dangerous area It is kept in the safe area without reaching.

In other words, since the head impact characteristic is determined based on acceleration and time, the head impact characteristic is not necessarily reduced even when a large impact energy is absorbed. In other words, the head impact characteristic may be improved by increasing the initial acting force applied to the head of the pedestrian to some extent within a predetermined short time without maintaining a relatively small acting force for a relatively long time.

In addition, WSTC is experimental data obtained assuming that the applied acceleration is linear.

In practice, however, the WSTC cannot be directly applied to the actual impact on the pedestrian head because the actual impact energy received by the head impactor upon impact with the hood is not linear but rather has a complex acceleration waveform. Therefore, a method of employing a HIC (Head Injury Criterion) value is well known as a method of evaluating safety based on WSTC and various impact test results using an impact body.

The HIC value can be inferred from the following equation.

Here, t1 and t2 represent a predetermined time (0t1t2) when the acceleration is applied, and a (t) represents the acceleration at the center of gravity of the head. The smaller the HIC value, the higher the safety will be. The safety limit is generally determined as HIC = 1000.

According to the above formula, the HIC value (1) first obtains an average acceleration between the times t1 and t2, (2) increases the obtained average acceleration a ₁₂ to 2.5 powers, and (3) increases the time (t2-t1) to the increased acceleration. Can be calculated as the maximum of what is obtained by multiplying Therefore, since the HIC value differs in principle when the impact behavior (acceleration waveform) is different, the HIC value can be determined based on the average acceleration a ₁₂ and the time t 2 -t 1. Further, since the relationship between the average acceleration a ₁₂ and the time t2-t1 can be replaced by the relationship between the hood action force and the hood stroke (movement distance), the HIC value can be determined based on the action force and the stroke of the hood.

As described above, since a large amount of impact energy can be absorbed, the HIC value does not necessarily decrease uniformly, that is, even if the amount of absorbed impact energy is the same, the HIC values may be different from each other. In addition, even if the HIC value is small only at a single point on the hood, the HIC value may be large at other points on the hood.

Therefore, in the conventional hood structure as shown in FIG. 1A, the force for collapsing the punching protrusion 19 whose cross section is deformed into a circular arc is not increased suddenly, so that it is relatively large for a relatively long time. There is a possibility that the working force is maintained. Therefore, in order to reduce the head impact characteristic, it is necessary to reduce the collapse force of the punching protrusion 19 and to increase the strobe of the hood. In other words, in the conventional hood structure as shown in Figs. 1A and 1B, it is necessary to arrange the hood at a relatively high position vertically from the engine to increase the stroke of the hood, so that the front view angle of the vehicle is narrowed. Problems arise.

Therefore, in view of the above problems, an object of the present invention is to reduce the HIC (Head Injury Criterion) value effectively to absorb shock energy sufficiently and safely despite the relatively short stroke of the hood or fender, that is, to reduce the head impact characteristics. To provide a front upper side of the vehicle (eg, hood, fender, etc.).

Figure 1a is a perspective view showing a hood structure of a conventional vehicle.

FIG. 1B is an enlarged perspective view showing only main parts of the hood shown in FIG. 1A. FIG.

FIG. 1C is a cross-sectional view taken along the line 1C-1C shown in FIG. 1B.

2 is a diagram showing the safe area and the dangerous area based on the relationship between various effective accelerations and time.

3 is a cross-sectional view showing a first specific example of the hood structure of a vehicle according to the present invention taken along line 3-3 shown in FIG.

4 is a plan view of the hood shown in FIG.

5 is an enlarged plan view of the shock absorber.

6 is a diagram showing an ideal impact energy absorption waveform (Cm).

7A to 7C are cross-sectional views showing three basic structures for explaining the first specific example of the hood structure according to the present invention.

8a to 8c are diagrams showing the relationship between the hood action force F and the hood stroke S. FIG. 8a corresponds to the basic structure shown in FIG. 7a with the ideal impact energy absorption waveform Cm. The impact energy absorption waveform C1 is shown, and FIG. 8b shows the impact energy absorption waveform C2 corresponding to the basic structure shown in FIG. 7b, and FIG. 8c is the impact energy corresponding to the basic structure shown in FIG. 7c. The absorption waveform (C3) is shown.

9 is a chart showing the relationship between the gap (gap between the hood outer panel and the engine) and the HIC value.

10A and 10B are cross-sectional views showing other basic structures.

11A to 11C are perspective views showing the actual shock absorber.

12 is a plan view showing a modification of the first specific example of the hood structure.

FIG. 13 is an enlarged plan view of the shock absorber shown in FIG. 12; FIG.

14A to 14C are perspective views showing the actual shock absorber.

15 is a cross-sectional view showing a second embodiment of the hood structure of the vehicle according to the present invention.

FIG. 16 is a plan view showing the hood shown in FIG.

FIG. 17 is a cross-sectional view taken along the line 17-17 shown in FIG.

18 is a perspective view showing an impact absorber provided with a sound absorbing material.

19 is a cross-sectional view showing a third embodiment of the hood structure of a vehicle according to the present invention.

FIG. 20 is a cross-sectional view taken along the line 20-20 shown in FIG. 19. FIG.

21A to 21E are sectional views showing the deformation order of the basic structure in the impact test.

22A to 22E are sectional views showing the deformation procedure of the hood of the third embodiment in the impact test.

23 is a chart showing the basic impact energy absorption waveform (C4) and the ideal impact energy absorption waveform (Cm) of the third embodiment.

24 is a perspective view showing a fourth embodiment of the hood structure according to the present invention.

25 is a cross-sectional view taken along the line 25-25 shown in FIG.

FIG. 26 is a plan view showing only main parts of a fourth embodiment of the hood structure shown in FIG. 24; FIG.

FIG. 27 is a cross sectional view taken along the line 27-27 shown in FIG.

FIG. 28 is a cross sectional view taken along the line 28-28 shown in FIG.

Fig. 29 is a sectional view showing the basic structure of the fourth embodiment.

FIG. 30 is a plot showing the basic impact energy absorption waveform (C1) along with the ideal impact energy absorption waveform (Cm).

31 is a cross-sectional view for explaining the function of the fourth concrete example.

32 is a plan view showing a modification of the fourth concrete example of the hood structure.

FIG. 33 is a cross sectional view taken along line 33-33 shown in FIG.

34 is a sectional view showing only main parts of a fifth embodiment of the hood structure according to the present invention;

35 is a perspective view of a fifth embodiment shown in FIG. 34;

36 is a perspective view showing only main parts of a sixth embodiment of a hood structure of a vehicle according to the present invention;

FIG. 37 is a cross sectional view taken along line 37-37 of FIG. 36;

38 is a cross-sectional view showing a basic structure of a sixth embodiment.

FIG. 39 is a chart showing the basic impact energy absorption waveforms C21 and C22 together with the ideal impact energy absorption waveform Cm.

40 is a perspective view showing a main portion of a seventh specific example of a hood structure of a vehicle according to the present invention;

FIG. 41 is a cross-sectional view taken along the line 41-41 of FIG. 40. FIG.

42 is a cross-sectional view showing a basic structure of a seventh embodiment.

FIG. 43 is a chart showing a basic impact energy waveform (C23) with an ideal impact energy absorption waveform (Cm).

44 is a perspective view showing the main parts of an eighth embodiment of the hood structure of a vehicle according to the present invention;

45 is a cross sectional view taken along the line 45-45 of FIG.

FIG. 46 is a cross sectional view taken along line 46-46 of FIG. 44;

Fig. 47 is a sectional view showing the basic structure of the eighth embodiment.

FIG. 48 is a plot showing the basic impact energy waveform (C24) along with the ideal impact energy absorption waveform (Cm).

49 is a sectional view for explaining the function of the eighth embodiment.

50A is a sectional view of another inner rib of a ladder cross section;

50B is a sectional view of another inner rib of a triangular cross section;

51 is a perspective view of a hood structure in which the distance between the hood outer panel and the engine is not constant.

52 is a perspective view showing a front upper structure of a vehicle.

FIG. 53 is a cross sectional view of a comparison fender structure taken along line 53-53 of FIG. 52;

FIG. 54 is a sectional view showing a ninth embodiment of the structure according to the present invention taken along line 53-53 of FIG. 52;

FIG. 55 is a half plan view showing the fender structure shown in FIG. 53;

FIG. 56 is a chart showing basic impact energy absorption waveforms (Cb) and improved impact energy absorption waveforms (Ca) (Cm) of the fender structure of Embodiment 9;

57A is a sectional view for explaining an impact stage of a fender structure in an impact test for obtaining a basic impact energy absorption waveform;

57B is a perspective view for explaining a deformation state of the fender structure in the same impact test.

58A is a sectional view for explaining another impact step of the fender structure in the impact test for obtaining the basic impact energy absorption waveform.

58B is a perspective view for explaining another deformation state of the fender structure in the same impact test.

59A is a cross sectional view for explaining another impact step of a fender structure in an impact test for obtaining a basic impact energy absorption waveform;

59b is a perspective view for explaining another deformation state of the fender structure in the same impact test.

60A is a cross-sectional view for explaining the impact stage of the fender structure in the impact test for obtaining the improved impact energy absorption waveform.

60b is a perspective view for explaining a deformation state of the fender structure in the same impact test.

61A is a cross sectional view for explaining another impact step of a fender structure in an impact test for obtaining an improved impact energy absorption waveform;

61B is a perspective view for explaining another deformation state of the fender structure in the same impact test.

62A is a cross sectional view for explaining another impact step of a fender structure in an impact test for obtaining an improved impact energy absorption waveform;

62B is a perspective view for explaining another deformation state of the fender structure in the same impact test.

FIG. 63 is a sectional view showing a modification of the ninth embodiment of the fender structure according to the invention taken along line 53-53 in FIG.

* Explanation of symbols for main parts of the drawings

31,131,231: Hood 33,133,233: Hood outer panel

35,135,235: engine room 37,253: engine

39: inner panel 41,239: inner rib

43,83,171: shock absorber 45: support bracket

47: shock absorbing member fixing portion 49: arm portion

53: cover 55,161,255: impactor

57: lower side plate 59: side plate

65: lower plate 67: vertical wall

77: protrusion 89,151: tower

91: sound absorbing material 95: hood

137,237: hood inner panel 141: plate part

147,167 Bumper Rubber 149: Hood Ridge

155,157,159,165: shock absorbing member 160: bumper rubber attachment member

171: shock absorber 251: reinforcing plate member

267: hard brittle member 1100: fender

1200: hood ridge reinforcement 1400: hood

1500: Bumper

In order to achieve the above object, the present invention stops the front upper outer panel, the shock absorbing means disposed below the front upper outer panel to absorb the impact applied to the front upper outer panel during deformation, and the modified shock absorbing means. A shock interfering body disposed below the shock absorbing means, and the impact energy absorption rate of the shock absorbing means and the total hollow gap formed between the front upper outer panel and the impact interfering body are based on the head impact criterion at the shortest stroke of the front upper panel. In order to effectively reduce the impact of the present invention provides a front upper structure for absorbing the impact applied to the front upper body of the vehicle during the collision, the impact energy generated during the collision is determined to be absorbed in accordance with the ideal impact energy absorption waveform.

Here, the ideal impact energy absorption waveform is the relationship between the action force and the stroke of the deformed front upper panel, and is obtained based on the amount of impact energy to be absorbed at the time of collision, and calculated according to the following head impact criteria analogy.

[Equation 1]

[Equation 2]

Where HIC represents the head impact criterion, a (t) represents the acceleration at the center of gravity of the test impact body, t1 and t2 represent the predetermined time (0t1t2) the acceleration is applied, and (t1, t2) aiL up to max) represents the maximum selected from [a ₁₂ ^2.5 (t2-t1)]. In addition, the shock absorbing means is deformed at a relatively appropriate energy absorption rate in the collision to generate the secondary reaction force required for the ideal shock energy absorption waveform.

The present invention also provides a hood outer panel for closing the engine compartment, shock absorbing means disposed under the hood outer panel to absorb shocks applied to the hood during deformation, and shock absorbing to stop the modified shock absorbing means. An impact interfering body disposed below the means, the impact energy absorption rate of the shock absorbing means and the total hollow gap formed between the hood outer panel and the impact interfering body collide to effectively reduce the head impact criterion at the shortest stroke of the front upper panel. Provided is a hood structure for absorbing a shock applied to a hood of a vehicle at the time of a collision, wherein the impact energy generated at the time is determined to be absorbed in accordance with an ideal shock energy absorption waveform.

Here, the ideal impact energy absorption waveform is the relationship between the action force and the stroke of the deformed hood outer panel, which is obtained based on the amount of impact energy to be absorbed at the time of the impact and by calculating according to the two head impact criteria analogies, The shock absorbing means is deformed at a relatively appropriate energy absorption rate at the time of collision to generate the secondary force required for the ideal shock energy absorption waveform. In addition, the predetermined total hollow gap is about 20 mm.

In a first aspect of the invention, the impact interceptor is an engine 37 and the shock absorbing means is a plurality of shock absorbers supported by a support bracket fixed to the hood outer panel 33 under the hood outer panel to cover the engine. (43).

Here, each of the shock absorbers 43 is a shock absorbing member 43a formed by winding a plate material 56 having a substantially rectangular cross section in a coil shape. Each shock absorber 43 is composed of an upper side and a lower side plate 57 and two side plates 59 and formed in a substantially rectangular cylindrical shape. The upper side and lower side plate 57 has a plurality of large holes. 61 is formed, and a number of small holes 63 are formed in the two side plates 59 to adjust the impact energy absorption rate. Each shock absorber 43 is a shock absorbing member 43c composed of a plurality of vertical walls 67 formed between the upper and lower plates 65 and the upper and lower plates 65. The shock absorber 43 is made of aluminum or resin.

Further, in a variant of the present invention, the impact interceptor is an engine 37 and the shock absorbing means is supported by a support bracket 45 fixed to the hood outer panel 33 under the hood outer panel to cover the hood outer panel. One shock absorber (69). The shock absorber 69 is a shock absorbing member 69a formed by punching a plurality of cutouts 73 at approximately right angles to the plate material 75 as the raised piece 75. The shock absorber 69 is formed by punching a plurality of rectangular protrusions 77 on the plate material 71 such that the bottom 77b of each protrusion 77 is connected to two inclined portions 77a. (69b). The shock absorber 69 is a shock absorbing member 69c formed by punching a plurality of right-angled triangular protrusions 77 on the plate material 71 such that the inclined portion 77a is connected to the vertical portion 77b.

In a second aspect of the invention, the impact interceptor is an engine 37 and the shock absorbing means is a shock absorber 83 provided under the hood outer panel 33 to cover the engine, with the shock absorber 83 in the center thereof. The upper plate member (83a) and the lower plate member (83b) is formed so as to form a closed cross section (N) is fixed to two support towers (89) provided on both sides of the engine room. Here, a plurality of holes 93 are formed in the upper and lower plate members 83a and 83b of the shock absorber 83 to adjust the shock energy absorption rate of the shock absorber 83, respectively. The lower plate member 83b is formed with a recess 86 for passing the wire member 85 connected to the engine.

The closed end surface N of the shock absorber 83 is filled with a sound absorbing material 91 to reduce engine noise. The sound absorbing material is glass wool.

In addition, in the third aspect of the present invention, the hood structure includes a hood inner panel 39 formed with a hood inner rib 41 and bonded to an inner surface of the hood outer panel 33.

In addition, in the fourth aspect of the present invention, the impact interfering body is a pair of support towers 151 provided on both sides of the engine room 135, and the shock absorbing means includes a support plate upper hood inner panel 137a and a hood outer panel ( 133 and a plurality of shock absorbing members 157, 155, 159 disposed between the hood inner panel 137a. Here, the plurality of shock absorbing members are disposed on each side of the hood so that the cross section is formed in a hat shape, respectively, and the bolt 152 of the support tower 151 between the hood outer panel 133 and the base plate upper hood inner panel 137a. ) And an outer shock absorbing member 159 coupled to a position corresponding to the nut 153, two intermediate shock absorbing members 155, and an inner shock absorbing member 157. In addition, the shock absorbing member is composed of a bumper rubber mounting member 160 formed by punching the support plate upper hood inner panel 137a downwardly from the outer shock absorbing member 159 in the shape of a hat, and the bumper rubber 147 is formed on each bearing. It is attached to the bumper rubber mounting member 160 on the upper side of the tower 151. The two intermediate shock absorbing members 165 are formed by punching the base plate upper hood inner panel 137a into hat-shaped protrusions, respectively, and are joined to the hood outer panel 133. The plurality of shock absorbing members 159, 155, and 157 are bonded between the hood outer panel 133 and the base top hood inner panel 137a using gum mastic resin.

In addition, in the fifth aspect of the present invention, the impact interceptor is a pair of support towers 151 provided on both sides of the engine room 135, and the shock absorbing means is an upper side of the support tower 151 to cover the support tower. Two shock absorbers 171 attached to 151a, respectively, which are each bent inward to be fixed to the support tower with an upper plate portion 181, bolts 152 and nuts 153, respectively. A number of straight legs 173, 175, 177 are formed. Here, the upper plate portion 181 is formed with a plurality of holes 171 for adjusting the impact energy absorption rate of the shock absorber. The shock absorber 171 is also composed of a bumper rubber 167 formed of elastic resin and attached to the upper plate portion 181 of the shock absorber 171.

Further, in the sixth aspect of the present invention, the impact interfering body is an engine 253, and the shock absorbing means includes an elongated channel type inner rib 239L having an outer flange portion 245, and an outer flange portion 245, respectively. An inner panel having two short channel-shaped inner ribs 239S intersecting the elongated channel inner ribs 239L with a predetermined distance therebetween and joined to the hood outer panel 233 at a plurality of different points to cover the engine. 237, wherein each intersection of the long and short channel ribs is connected through bends on both sides thereof, and two parallel straight portions 249 between the two intersections are each reinforced by the reinforcing plate member 251. Here, the inner panel 237 is bonded to the outer panel 233 on the entire surface of the flange portion 245 by using gum directed resin.

In addition, in the seventh aspect of the present invention, the impact interferer is an engine 253, and the shock absorbing means includes an elongated channel type inner rib 239L having an outer flange portion 245 and an outer flange portion 245, respectively. And intersect the long channel-shaped inner ribs 239L with a predetermined distance therebetween and joined to the hood outer panel 233 over the entire surface of the flange portion 245 of the ribs 239L and 239S to cover the engine. An inner panel 233 having a short channel-shaped inner rib 239S is formed, and each intersection of the long and short channel-shaped ribs is connected through curved portions on both sides thereof. Here, the inner panel 237 is bonded to the outer panel 233 on the entire surface of the flange portion 245 by using a gum direct resin.

In addition, in an eighth aspect of the present invention, the impact interfering body is an engine 253, and the shock absorbing means is formed in the inner panel 239 to cover the engine, and is formed with a straight inner rib 267 covered with a hard brittle member 267. 239A), wherein the inner ribs covered with the hard brittle member will stratify the engine. Here, the inner ribs 239A are provided with a plurality of slits 269 on both sides thereof to adjust the impact energy absorption rate. The cross-sectional shape of the ribs 239A is rectangular, ladder-shaped or triangular.

In addition, the present invention provides a fender panel 1100 having a vertical wall 1101 having a stepped portion FA formed thereon so as to be bent and easily broken in the upper protrusion 1110, and a fender to absorb the impact applied to the fender during deformation. A shock absorbing means disposed on a vertical wall of the shock absorbing means, and a hood ridge reinforcing member 1200 for stopping the deformed shock absorbing means. The impact energy absorption rate of the shock absorbing means is based on a head impact criterion at the shortest stroke of the fender panel. Provided is a fender structure for absorbing the impact applied to a fender of a vehicle in a collision, which is determined so that the impact energy generated during a collision can be absorbed according to an ideal impact energy absorption waveform to effectively reduce the impact.

Here, the ideal impact energy absorption waveform is an ideal relationship between the working force and the deformed fender's stroke, which is obtained based on the amount of impact energy that must be absorbed in the collision and calculated according to the two head impact criterion inference equations, The shock absorbing means is deformed at a relatively appropriate energy absorption rate at the time of collision to generate the secondary force required for the ideal shock energy absorption waveform.

The shock absorbing means is a synthetic resin layer 1002 attached on the inner side surface of the step FA of the vertical wall 1101. The synthetic resin layer 1002 covers approximately half or the entire surface of the step FA of the vertical wall 1101. In addition, the thickness of the synthetic resin layer 1002 is thin on the front side of the vehicle and thick on the rear side. In addition, a recess 1003 is formed in the hood ridge reinforcing member 1200 to accommodate the broken synthetic resin layer 1002.

As described above, in the front upper side (hood or fender) structure according to the present invention, the total energy between the impact energy absorption rate of the reinforcing layer and the front upper side outer panel (hood outer panel or fender panel) and the impact interference body (engine or support tower). The hollow gap is determined so that the impact energy generated during the collision can be absorbed according to the ideal impact energy absorption waveform so that the front upper panel can effectively reduce the head impact criterion in the shortest stroke. Therefore, since the shock absorbing means is deformed and deformed since the reinforcing layer starts to interfere with the impact interfering body when the front upper outer panel moves by a predetermined stroke, the desired secondary action force required for the ideal shock energy absorption waveform can be generated. As a result, it is possible to absorb impact energy under ideal absorption conditions, and as a result, the HIC value can be reduced even in a small stroke of the hood, that is, the head impact characteristic can be steadily reduced.

Hereinafter, a specific example of a hood structure of a vehicle according to the present invention will be described in detail with reference to the accompanying drawings. A feature of the hood or fender according to the invention is to effectively reduce the HIC value while reducing the head impact characteristics by reducing the stroke of the hood or fender of the vehicle under severe conditions.

In order to attain the above-mentioned characteristics, in practice (in order to reduce both the deformation stroke and the HICT value), the ideal impact energy absorption waveform (Cm) (hereinafter referred to as the ideal shock waveform (Cm), which represents an ideal relationship between the hood or fender force and the hood or fender stroke) Is first calculated based on the amount of impact energy to be absorbed at the time of collision and according to HIC inferences (1) and (2). Secondly, the actual (non-improved) impact energy absorption waveform (hereinafter referred to as the basic shock waveform) is obtained from an impact test conducted at a predetermined hood or fender position. Thirdly, the hood or fender structure is determined so that the basic shock waveform reaches the ideal shock waveform so that the HIC value can be effectively and reliably reduced even with short strokes of the hood or fender.

Here, the effective hood or fender structure for approaching the basic (non-improved) shock waveform to the ideal shock waveform is not constant according to various conditions such as the basic hood structure of the impact test, permissible hood stroke, etc. Only the most effective hood or fender structure will be described for each.

The ideal shock waveform (Cm) represents how the basic structure of the hood or fender is designed to reduce head impact properties, even with small strokes of the hood or fender. Therefore, the hood or fender structure of the embodiment of the present invention is constructed based on the design concept described above.

A first embodiment of the present invention will now be described with reference to FIGS. 3 to 5. 3 is a cross-sectional view taken along the line AB-AB of FIG. 4, FIG. 4 is a plan view showing the hood, and FIG. 5 is an enlarged view of the shock absorber shown in FIG.

As shown in FIG. 3 and FIG. 4, the hood 31 is comprised from the hood outer panel 33, the inner panel 39, and the hood cover 53. As shown in FIG. The hood outer panel 33 is used to close the upper side of the engine compartment 35. The engine 37 (acting as an interference body) is arranged in the middle of the engine room 35. The inner panel 39 is joined to the lower (inner) surface 33a of the hood outer panel 33 from the side of the engine room 35. The inner panel 39 is formed with a plurality of cap-shaped inner ribs 41 protruding downward into the engine room 35 so as to surround the hood outer panel 33 positioned on the engine 37. In addition, the shock absorber 43 is disposed between the hood outer panel 33 and the engine 37.

4 and 5, the shock absorber 43 has a hood outer panel 33 parallel to each other along the width direction of the vehicle so that both ends of each impact member are connected between the two support brackets 45. As shown in FIG. It consists of two shock absorbing members (43a, 43b or 43c) arranged on the side. As shown in FIG. 5, each of the support brackets 45 extends radially from the shock absorbing member mounting portion 47 for mounting and fixing the shock absorbing members 43a, 43b or 43c and the ends of the shock absorbing members, respectively. Two arm portions 49 are formed. As shown in FIG. 3, the end portion 49a of each arm portion 49 of the support bracket 45 is connected to the inner rib 41. Further, each arm portion 49 is provided with an easy deformation portion 51 so that the shock absorber 43 can be deformed below the vehicle.

Meanwhile, a cover 53 is disposed between the shock absorber 43 and the engine 37 to cover the lower surface of the shock absorber 43. In addition, a predetermined distance between the hood outer panel 33 and the engine 37 so that the shock absorber 43 starts to interfere with the engine 37 when the hood outer panel 33 is deformed below the vehicle body by a predetermined distance. A gap is formed. In other words, the above-mentioned predetermined distance includes the gap D1 between the hood outer panel 33 and the shock absorber 43, the gap D2 between the shock absorber 43 and the cover 53, and the cover 53. The sum of the gaps D3 between the engines 37, which is about 20 mm in the first embodiment.

11A to 11C, the actual shape of the shock absorbing members 43a to 43c used in the first embodiment will be described in detail.

The shock absorbing member 43a shown in FIG. 11A is formed by winding a plate material 56 having a substantially rectangular cross section into a coil shape. The shock absorbing member 43b shown in FIG. 11B is composed of an upper and lower side plate 57 and two side plates 59, and is formed in a substantially rectangular cylinder shape. In addition, a plurality of rectangular large holes 61 are formed in the upper and lower plates 57, and a plurality of small slits 63 are formed in the two side plates 59. In addition, the shock absorbing member 43c shown in FIG. 11C is composed of a plurality of vertical walls 67 connected between the upper and lower plates 65 and the upper and lower plates 65. These shock absorbing members 43a to 43c are made of a metal material (for example, aluminum) or resin.

Hereinafter, the function of the hood structure will be described in detail with reference to FIGS. 6 to 10.

In the hood of this embodiment, when the shock is applied to the hood 31 positioned on the engine 37, and the hood outer panel 33 interferes with the engine 37, the HIC value at the above-described position decreases, so that the hood outer panel 33 It is configured to alleviate the head impact characteristics of the hood 31 in the shortest stroke of. For this reason, this structure is determined to obtain a shock waveform close to the ideal shock waveform Cm. Here, the ideal shock waveform (Cm) means the ideal relationship between the hood action force (F) and the hood stroke (5) by the hood deformation, which can effectively reduce the HIC value despite the short stroke in the impact test. Further, the ideal shock waveform Cm can be calculated on the basis of the amount of impact energy to be absorbed in the collision as described above, and according to equations (1) and (2).

FIG. 6 shows the ideal shock waveform (Cm), FIGS. 7A-7C show the basic structural model of the impact test, and FIGS. 8A-8C are obtained using the basic structural model together with the ideal shock waveform (Cm). Basic shock waveforms (C1), (C2) and (C3) are shown.

With reference to the ideal shock waveform Cm in FIG. 6 (ideal shock waveform Cm), FIGS. 7a to 7c (basic structural model), and FIGS. 8a to 8c (basic shock waveforms C1, C2, C3) It will be described in more detail.

FIG. 6 shows the ideal shock waveform Cm which represents the ideal relationship between the action force F and the hood stroke S, which can reduce the stroke (travel distance) and HIC value of the hood 59 when the basic structure is used. . In Fig. 6, the inner region A blocked by the ideal shock waveform Cm and the stroke S (lateral coordinate) represents the impact energy to be absorbed. Therefore, this inner region should be determined to be equal to the amount of impact energy to be absorbed. In addition, the amount of impact energy to be absorbed in a collision can be obtained based on various impact tests and calculations.

In the ideal shock waveform Cm shown in FIG. 6, the initial action force F due to the initial deformation of the hood outer panel 33 rapidly increases at a relatively small stroke S, so that the maximum action force at the stroke S1. (F1) (Pm) is reached. Thereafter, the action force F drops rapidly from the stroke S2 to the F2. In the second deformation part after the stroke S2, since the secondary action force (described later) is generated, the reduction rate (gradient) of the action force F is lowered, and the shoulder portion qm appears. In addition, when the stroke reaches S3, the action force F rapidly decreases and reaches approximately zero in the stroke S0, where the impact energy is completely absorbed.

The basic structure of the impact test will be described with reference to FIGS. 7A to 7C.

In the basic structure shown in FIG. 7A, the shock absorber 43 is provided between the hood outer panel 33 and the engine 37. As shown in FIG. The shock absorber 43 is mounted on the upper side 37a of the engine 37, and a predetermined gap d is formed between the hood outer panel 33 and the upper side of the shock absorber 43. In the impact test, the impactor 55 collides with the hood outer panel 33 on the shock absorber 43, and the acceleration and stroke (moving distance) of the impactor 55 are measured. The measured acceleration and stroke of the impactor 55 correspond to the action force F (vertical coordinate) and stroke S (abscissa) of the hood outer panel 33 due to hood deformation, both of which are shown in FIG. 8A. It is.

Thus, as shown in FIG. 8A, the basic shock waveform C1 approximating the ideal shock waveform can be obtained.

On the other hand, Figure 7b shows a basic structure in which the shock absorber 43 is not provided. In this case, the shock waveform C2 shown in FIG. 8B can be obtained. 7C also shows a basic structure in which only the shock absorber 43 is provided without providing the hood outer panel 33. In this case, the shock waveform C3 shown in FIG. 8C can be obtained.

Therefore, it can be understood that the impact waveform C1 shown in FIG. 8A can be conceptually obtained by the combination of the impact waveforms C2 and C3 shown in FIGS. 8B and 8C.

Specifically, in the case of the impact test in which only the hood outer panel 33 is provided without providing the shock absorber 43 as shown in FIG. 7B, the shock waveform C2 shown in FIG. 8B can be obtained. . In the initial deformation immediately after the impact, the hood outer panel 33 is locally deformed along the contour of the impactor 55, so that the initial action force F suddenly increases due to the tension of the hood outer panel 33, and thus the stroke S1. ) The maximum working force (F1) (P1). After the maximum action force, the force force F suddenly decreases to zero action force with the increase of the stroke S since the hood outer panel 33 starts to deform from the surface in a large area due to the inertia force of the impactor 55. do. In this case, since a sufficient amount of impact energy absorbed up to this stage (area A1 in FIG. 8A) cannot be obtained, the hood outer panel 33 is further deformed and then interferes with the upper surface 37a of the engine 37. Stops later.

Thus, when the hood outer panel 33 and the engine 37 interfere with each other, another amount of impact energy (area A2 in FIG. 8A) must be absorbed. Therefore, it can be understood that the impact energy amount (region A2) must be absorbed by the shock absorber 43 in order to reduce the deformation stroke S. FIG.

As shown in FIG. 7C, in the case of an impact test in which only the shock absorber 43 is provided without providing the hood outer panel 33, the shock waveform C3 shown in FIG. 8C can be obtained. In this case, since the hood outer panel 33 interferes with the shock absorber 43 which is delayed due to the gap between the hood outer panel 33 and the upper side of the shock absorber 43, the shock absorber 43 starts to deform later. The amount of impact energy absorbed corresponds to the area A2.

Therefore, when the gap d between the hood outer panel 33 and the shock absorber 43 is determined to be a predetermined gap, the shock waveform (C1) is combined with the shock waveforms C1 and C2 shown in FIG. 8A. C1) can be obtained, which approaches the ideal shock waveform (Cm). Further, in FIG. 8A, the area A surrounded by the waveform C1 and the abscissa is the sum of the areas A1 and A2, which corresponds to the amount of impact energy absorbed. 8A also shows that the impact energy must be absorbed almost completely by the shock absorber 43 before the hood outer panel 33 interferes with the engine 37. In addition, FIG. 8A shows that the shock absorber 43 can absorb the impact energy at a relatively small reduction rate (small negative gradient) with respect to the stroke S, thereby generating a secondary action force to form the shoulder portion at the impact waveform C1. Indicates.

FIG. 9 shows the HIC values obtained by various impact tests in which the gap d between the hood outer panel 33 and the upper side of the shock absorber 43 is changed as in FIG. 7A. 9 shows that the HIC value decreases as the gap d increases or decreases. In addition, it can be understood that the HIC value decreases relatively rapidly until the gap d increases to about 20 mm, but is relatively gentle after the gap d increases to 20 mm or more. On the other hand, in order to ensure the driver's forward field of view (visible range), the gap between the hood outer panel 33 and the shock absorber 43 is preferably as small as possible. Therefore, to reduce the HIC value and hood stroke, the gap d should be determined to be about 20 mm.

10A also illustrates a case in which a shock absorber 43 is provided on the inner side surface of the hood outer panel 33 so that a gap d is formed between the lower side of the shock absorber 43 and the engine 37. 10b shows that the shock absorber 43 is provided in the middle between the hood outer panel 33 and the engine 37 so that the gap d is below the gap d1 and the shock absorber 43 above the shock absorber 43. The case where it is the sum of gap d2 is shown. In both cases shown in FIGS. 10A and 10B, the same result as shown in FIG. 7A (a gap d is provided between the hood outer panel 33 and the upper side of the shock absorber 43). Can be obtained. In summary, the total gap of the gaps formed between two adjacent elements among all the elements interposed between the hood outer panel 33 and the engine 37 is preferably determined to be d = 20 mm.

As described above, in this embodiment, the hood 31 (see FIG. 3) is provided such that the gap between the hood outer panel 33 and the engine 37 is (D1 + D2 + D3 = 20mm). When applying the impact test, a shock waveform C1 (shown in FIG. 8) approximating the ideal shock wave (Cm) (shown in FIG. 6) can be obtained as follows. That is, in the initial deformation, since the hood outer panel 33 is locally deformed along the outer shape of the impactor 55, the initial action force F increases rapidly from the stroke (approximately S2) to the maximum action force (approximately F1). . After the maximum force F1, the hood outer panel 33 begins to deform from the surface in a wide area due to the inertia force of the impactor 55, so the force F rapidly decreases from stroke S2 to approximately F2. do. After that, since the hood outer panel 33 interferes with the shock absorber 43, a preferable secondary action force is generated by the shock absorber, so that an obvious shoulder qm can be obtained in the shock waveform C1. In addition, when the shock absorber 43 is sufficiently destroyed to completely absorb the impact energy, the action force F decreases rapidly to approximately zero again.

Therefore, in this embodiment, the shock wave C1 close to the ideal shock wave Cm can be obtained, so that the HIC value can be effectively reduced despite the relatively short stroke of the hood outer panel 33. Head impacts on pedestrians can be mitigated in a crash.

In addition, since the shock absorber 43 is provided on the hood side without providing the shock absorber 43 on the engine room 35 side, the engine room 35 is simplified, and thus the additional effect of improving the freedom of design is improved. Occurs.

Modifications of the first embodiment of the hood structure according to the present invention will be described with reference to FIGS. 12 to 14c. In this modification, instead of the two shock absorbing members 43a, 43b or 43c as shown in FIGS. 11A to 11C, the plate-shaped shock absorber 69 is covered to cover the upper surface 37a of the engine 37. ) Is provided. This shock absorber 69 is also supported by the support bracket 45 in the same manner as in the case of the shock absorber 43.

14A to 14C show the actual shapes of the shock absorbing members 69a to 69c, respectively. In the case shown in 14a, the impact absorbing member 69a is formed by cutting a plurality of cutouts 73 in the plate material 71, and the cutouts 73 are in the punching vertical piece 75. Is bent. In the case shown in Fig. 14B, the impact absorbing member 69b has two bottoms 77b of each protrusion 77 in punching a plurality of ladder-shaped protrusions 77 on the plate material 71. It is formed by processing to be formed between the inclined portion (77a) of. In the case shown in FIG. 14C, the impact absorbing member 69c punches a plurality of right-angled triangular protrusions 77 on the plate material 71 such that the inclined portion 77a is connected to the vertical portion 77b. Is formed.

As described above, when the shock absorber 69 is provided to cover the upper side 37a of the engine 37, the ideal shock waveform over almost the entire range of the hood outer panel 33 located above the engine 37 Since the impact waveform C1 approximating the Cm can be obtained, the HIC value can be effectively reduced despite the relatively short stroke of the hood outer panel 33, that is, the head impact characteristic on the head of the pedestrian can be alleviated in the event of a collision. have.

Hereinafter, a second embodiment of the hood structure according to the present invention will be described with reference to FIGS. 15 to 18. In the second embodiment, the shock absorber 83 is provided on the engine room 35 side.

In Figs. 15 to 18, the same reference numerals are maintained for similar parts having the same function as in the first embodiment.

FIG. 15 is a sectional view showing a hood structure of the vehicle body, FIG. 16 is a plan view of FIG. 15, and FIG. 17 is a sectional view taken along line 17-17 of FIG.

As shown, a shock absorber 83 is provided between the hood outer panel 33 of the hood 81 and the engine 37. The gap between the hood outer panel 33 and the engine 37 is the gap D4 between the hood outer panel 33 and the upper side 83a of the shock absorber 83 and the lower side 83b of the shock absorber 83. The sum of the gaps D5 between the engine and the engine 37 is determined to be about 20 mm as in the case of the first embodiment.

Two support towers 89 are provided on both sides of the engine room 35 in the width direction of the vehicle body so as to be inclined from the hood ridge portion 87 of the hood 81 to the inside of the vehicle. A cylindrical portion 89b is formed on each upper side 89a of the base tower 89, and three bolts and nuts 90 are arranged around the circumference of the cylindrical portion 89b.

On the other hand, the shock absorber 89 is formed by combining the upper plate body 83a and the lower plate body 83b so that the closed end surface N is formed between the upper and lower plate bodies 83a and 83b. The shock absorber 83 is joined to the upper surface 89a of the base tower 89 at both ends thereof so as to cover the engine 37 from the top. More specifically, the shock absorber 83 has two holes 84a coupled to the cylindrical portion 89b of the upper surface 89a of the two support towers 89 at both side portions 84 thereof. Therefore, after both ends 84 of the shock absorber 83 are coupled to the cylindrical portions 89b of the two support towers 89 on both sides in the vehicle width direction, the shock absorbers 83 are respectively bolts and nuts 90. It is fixed to the support tower (89). Therefore, when the shock absorber 83 is fixedly supported by the support tower 89, the support tower 89 can be prevented from falling inward, that is, the shock absorber 83 is used as the support tower reinforcing member.

In addition, since the wire member (for example, acceleration wire) 85 connected to the engine 37 is generally provided on the engine 37, the lower plate body 83b of the shock absorber 83 is shown in FIG. As the curved concave portion 86 is formed, a predetermined space can be maintained away from the wire member 85, that is, the shock absorber 83 can be prevented from interfering with the wire member 85.

In the above-described second embodiment, the total gap D4 + D5 between the hood outer panel 33 and the engine 37 is determined to be about 20 mm as in the first embodiment, so that the ideal shock waveform Cm Since an approximate shock waveform can be obtained, despite the relatively short stroke of the hood outer panel 33, the HIC value can be effectively reduced, that is, the head impact characteristic on the pedestrian head in the event of a collision can be alleviated.

In addition, since the shock absorber 83 is provided in the engine room 35, the weight of the hood 35 can be reduced, and thus the hood 81 can be easily opened and closed.

In addition, since the shock absorber 83 is supported by being coupled to the support tower 89, the support tower 89 can be prevented from falling without providing additional parts (eg, support tower rods). 89) improves the robustness of the vehicle to improve the running stability.

Further, since the shock absorber 83 is provided to cover the engine 37, the head impact characteristic of the entire surface of the hood outer panel 33 located on the engine 37 can be alleviated as in the first embodiment. .

In addition, the closed end surface N of the shock absorber 83 is preferably filled with a sound absorbing material 91 (for example, glass wool). In this case, the engine noise can be reduced because the engine 37 can be covered with the sound absorbing material 91. In addition, when a plurality of holes 93 are formed in the upper plate 83a and the lower plate 83b, the collapse force or impact energy absorption rate of the shock absorber 83 can be reliably adjusted, and the sound absorbing material 91 Sound absorption effect can be further improved.

Hereinafter, a third embodiment of the hood structure according to the present invention will be described with reference to FIGS. 19 and 20, wherein the inner rib 41 is additionally between the hood outer panel 33 and the shock absorber 83. Is provided. FIG. 19 is a sectional view showing a hood structure, and FIG. 20 is a sectional view taken along line 20-20 of FIG.

As shown in FIG. 19 and FIG. 20, the hood 95 of this embodiment consists of the hood inner panel 39 in which the hood outer panel 33 and the several hood inner ribs 41 were formed. The hood inner panel 39 is joined to the hood outer panel 33. The total gap between the hood outer panel 33 and the engine 37 is the gap D6 between the hood inner rib 41 and the upper side 83a of the shock absorber 83 and the lower side of the shock absorber 83. As the sum of the gap D7 between 83b) and the engine 37, it is determined to be about 20 mm as in the case of the first and second embodiments. In addition, when the gap G6 (gap between the shock absorber 83 and the hood outer panel 33) is deformed downward by a predetermined distance as the hood outer panel 33 is described later, the hood action force reaches a maximum value. The inner rib 41 is set to a predetermined value so as to start interfering with the shock absorber 83.

In addition, as in the case of the second embodiment, a shock absorber 83 is provided to cover the engine 37 from above, and both ends 84 are joined to the upper side 89a of the base tower 89. Therefore, since the shock absorber 83 is connected to and supported by the two support towers 89, the support tower 89 may be prevented from falling. In addition, as shown in FIG. 20, since the wire member 85 is usually disposed on the engine 37, the lower plate body 83b of the shock absorber 83 provides a predetermined space away from the wire member 85. As shown in FIG. A bending recess 86 is formed for this purpose.

Hereinafter, the functions of the third embodiment will be described with reference to FIGS. 21A to 23.

As in the case of the first embodiment, the hood 95 is formed such that a shock waveform approximating the ideal shock waveform Cm can be obtained in the impact test.

21A to 21E show the deformation state of the basic (non-improved) structure (without the shock absorber 83) in the impact test, and FIGS. 22A to 22E show the deformation of the hood 95 of this embodiment in the impact test. The deformed state is shown, and FIG. 23 shows the shock wave C4 of the basic (non-improved) structure together with the ideal shock wave Cm. In FIG. 23, the shock waveform obtained by the hood 95 of this embodiment is omitted because the ideal shock waveform Cm is approached in the impact test.

The basic hood structure shown in FIGS. 21A to 21E is basically the same as that of the third embodiment except that the shock absorber 83 is not provided. The relationship between the deformation state of the basic structure without the shock absorber 83 and the action force F and the hood deformation stroke S in the impact test will be described with reference to FIGS. 21A to 21E and 23.

As shown in FIG. 21A, when the impact body 55 (its initial speed V00) starts to interfere with the hood outer panel 33 in the initial stop state (its initial speed V0 = 0), the impact body 55 Since a force is applied to the hood outer panel 33 from the hood, the hood outer panel 33 is accelerated as shown in Fig. 21B. During this time, since the speed V1 of the impactor 55 is larger than the speed V1 of the inner rib 41 (V1V1), the hood outer panel 33 is locally deformed along the outer shape of the impactor 55. Therefore, as shown by the range I of FIG. 23, the initial action force rises from the point P4 to the maximum action force F1. Thereafter, the hood outer panel 33 starts to deform downward because of the inertial force of the impactor 55, and the action force F suddenly begins to decrease.

As shown in FIG. 23C, when the hood outer panel 33 is sufficiently accelerated such that the speed V ₂ of the impactor 55 is smaller than the speed v ₂ of the inner rib 41 (V ₂ v _2). ), The hood action force F reaches zero in stroke S2 as indicated by range II in FIG.

As shown in FIG. 21D, when the hood outer panel 33 is further moved so that the inner rib 41 starts to interfere with the engine 37, the speed V ₃ of the impact body 55 is not zero but is inward. Since only the velocity v ₃ of the rib 41 reaches zero (V ₃ 0, v ₃ = 0), the inner rib 41 absorbs the impact energy and is deformed and destroyed. Therefore, a high action force F occurs as indicated by range III in FIG.

As shown in FIG. 21E, when the inner ribs 41 are sufficiently deformed and the impact energy is fully absorbed, the hood 95 stops, so that the action force F is zero at the position IV in FIG. To reach.

As described above, the shock wave C4 of the basic (non-improved) structure is ideal only until the initial action force F of the hood outer panel 33 suddenly deforms from the initial deformation until the maximum action force P4 is reached. Approach the shock waveform (Cm).

However, in the shock wave C4 of the basic (non-improved) structure, the action force F decreases more abruptly after the maximum action force F1 than the ideal shock wave Cm and also after the action force F reaches F2. Since the force decreases directly to zero, the action force F does not relieve after (F2) and thus no shoulder qm is formed (because no secondary action force is generated by the shock absorber 83), and consequently the impact Waveform C4 differs significantly from ideal shock waveform Cm. In other words, it is not possible to obtain a sufficient amount of impact energy to be absorbed only by the impact energy (area A3 in FIG. 23) obtained before the inner ribs 41 interfere with the engine 37. FIG.

In addition, since the large amount of impact energy (area A4 in FIG. 23) is absorbed when the inner rib 41 interferes with the engine 37, a large working force F after a relatively long time has elapsed after the impact is started. (Referred to as r4 in FIG. 23), resulting in a detrimental effect on the head impact properties.

In contrast, in the third embodiment having the shock absorber 83 as shown in FIG. 22A, the impact body 55 (its initial speed V ₂ 0) is in an initial stop state (its initial speed v ₂ =). Since the force is applied to the hood outer panel 33 from the impactor 55 when it interferes with the hood outer panel 33 at 0), the hood outer panel 33 is accelerated as shown in FIG. 22B.

In the meantime, since the speed V ₁ of the impact body 55 is larger than the speed v ₁ of the inner rib 41 (V ₁ v ₁ ), the hood outer panel 33 is the impact body 55 similarly to the case of the basic structure. The local deformation along the contour of the N) increases the initial action force F to the maximum action force F1 at the point Pm in the range Im shown in FIG.

After the maximum action force, the hood outer panel 33 starts to deform downwards due to the inertia force of the impactor 55 on the wide side. At this time, since the inner rib 41 starts to interfere with the shock absorber 83, as shown in FIG. 22B, an acting force is generated by the interference between the inner rib 41 and the shock absorber 83, and thus the action force F is obtained. This can be prevented from suddenly decreasing. As a result, the action force F decreases almost as in the case of the ideal shock waveform Cm in the range IIm in FIG.

When the hood stroke S reaches a predetermined distance as shown in FIG. 22d, the inner rib 41 passes through the shock absorber 83 because the shock absorber 83 starts to interfere with the engine 37. As shown in FIG. Interference with engine 37. At this time, since the velocity V ₃ of the impactor 55 is not zero and only the velocity v ₃ of the inner rib 41 reaches zero (V ₃ 0, v ₃ = 0), the inner rib 41 is formed. And the shock absorber 83 both absorb shock energy and deform and destroy. Therefore, the preferred secondary action force can be generated by the shock absorber 83. That is, since the total reduction rate of the action force F can be alleviated, the shoulder portion qm can be obtained as in the ideal waveform Cm in the range III in FIG. As shown in FIG. 22E, the hood 95 stops after the inner ribs 41 are sufficiently deformed and the shock energy is completely absorbed, so that the acting force F is shown in FIG. ) To zero.

As described above, in the impact test of the hood 95 according to the present invention, the initial action force rapidly increases because the hood outer panel 33 is locally deformed along the outer shape of the impactor 55 during the initial deformation. . Therefore, the maximum working force F1 at the stroke S1 can be obtained. Thereafter, the hood outer panel 33 starts to deform in a wide area by the inertial force of the impactor 55. In this case, since the inner rib 41 interferes with the shock absorber 83, the action force F decreases at an appropriate reduction rate. When the stroke S reaches S2, the action force decreases to F2. After that, since both the inner rib 41 and the shock absorber 83 are deformed by interfering with the engine 37, a desired secondary action force may occur, so that the shoulder portion qm can be obtained in the shock waveform. In addition, after the inner rib 41 and the shock absorber 83 are sufficiently destroyed, the hood 95 stops because the action force decreases to zero again. Therefore, in this embodiment, a shock waveform approximating the ideal shock waveform Cm can be obtained as in the first embodiment.

Further, since the gaps D6 and D7 between the hood outer panel 33 and the engine 37 in the third embodiment are determined to be about 20 mm as in the first embodiment, the hood outer panel 33 and the shock absorber ( Since the gap D6 between 83 is determined to be a predetermined value, the action force can be reduced to an appropriate reduction rate after the maximum value, and the secondary action force can be reliably increased in the hood structure of the vehicle. Therefore, a shock waveform close to the ideal shock waveform Cm can be obtained and the HIC value can be effectively reduced in a short stroke, thereby alleviating the head impact characteristics.

In addition, in the third embodiment, since the shock absorber is provided on the engine room side, the weight of the hood 81 is reduced, so that the hood 81 can be easily opened and closed. In addition, since the shock absorber 83 is fixed to and supported by the support tower 89, vehicle driving stability can be improved. In addition, since the shock absorber 83 is provided to cover the entire upper side of the engine 37, the head shock characteristic can be alleviated at almost the entire surface of the hood outer panel 33 on the engine 37.

In addition, when the sound absorbing material is provided in the closed end face of the shock absorber 83, the engine noise can be reduced as in the second embodiment.

Hereinafter, a fourth embodiment of the hood structure of a vehicle according to the present invention will be described with reference to FIGS. 24 to 28. A feature of the fourth embodiment is to effectively reduce the HIC value on the pedestal 151.

FIG. 24 is a perspective view showing the hood structure, FIG. 25 is a sectional view taken along the line 25-25 of FIG. 24, FIG. 26 is a plan view showing the main part of the hood inner panel 137a, and FIG. 27 is a line 27-27 of FIG. 28 is a cross sectional view taken along the line 28-28 of FIG.

As shown in FIGS. 24 and 25, the hood outer panel 133 of the hood 131 blocks the upper side of the engine compartment 135, and the hood inner panel 137 is a hood on the engine compartment 135. It is attached to the inner panel of the outer panel 133. The hood inner panel 137 is formed with a hat-shaped inner rib 139 along the inner circumference of the hood outer panel 133 to increase the rigidity of the hood inner panel 137.

On both sides of the engine room 135, a support tower 151 is provided to protrude from the hood ridge 149 into the engine room 135. The bolts of the world are vertically provided on the upper surface 151a of each support tower 151, and a nut 153 is coupled to each bolt 152.

A hollow portion H is formed between the hood outer panel 133 and the hood inner panel 137a (forwardly referred to as the upper hood inner panel 137a) positioned on the base tower 151. The flat plate portion 141 is integrally formed on the hood inner panel 137 extending from the base tower upper hood inner panel 137a to the inner side of the inner rib 139. The base top hood inner panel 137a is formed near the bolt 152 and the nut 153 disposed on the top of the base 151. The inner surface 145a (see FIG. 25) of the inner rib 139a extending from the flat plate portion 141 is bonded to the hood outer panel 133 with an elastic resin 146 (for example, gum directed resin). The outer surface 145b (see FIG. 25) of the inner rib 139b extending from the flat plate portion 141 is press-coupled to the bent portion formed along the outer circumference 133a of the hood outer panel 133.

The hollow portion H formed between the inner top panel 137a of the support tower and the hood outer panel 133 near the bolt 152 and the nut 153 includes a plurality of shock absorbing members 155 in this embodiment. 1157 and 159 are arranged as shock absorbers. The base panel upper hood inner panel 137a and the shock absorbing members 155, 157, and 159 constitute a shock absorber. These shock absorbing members 155, 157, and 159 have two intermediate shock absorbing members 155 arranged in the middle of the flat plate portion 141, and one inner shock absorbing member 157 and one outer shock absorbing member 159. Are arranged in such a manner that they are arranged one inside and one outside of the flat plate portion 141 in the vehicle width direction. In addition, two intermediate shock absorbing members 155 are positioned on two bolts 152 and nuts 153, respectively, and the inner shock member 157 is a bolt 152 and a nut 153 of the base 151. Is located above one.

As shown in FIG. 27 taken along line 27-27 of FIG. 26, the outer shock absorbing member 159 is formed in a quadrangular or ladder-shaped (hat shape) cross section, and is joined to the hood outer panel 133. The connecting portion 159a, two straight leg portions 159b (each serving as an outer support portion) extending obliquely downward from both ends of the upper connecting portion 159a, and outwardly from both lower ends of the straight leg portion 159b. It is composed of two lower connection portions 159c that are bent and welded to the inner top panel 137a of the base tower.

In addition, a bumper rubber attachment member 160 for forming a shock absorber under the outer shock absorbing member 159 is formed in the inner top panel 137a of the support tower. The bumper rubber attachment member 160 is formed by punching the support top upper hood inner panel 137a in a rectangular or ladder-shaped (hat shape) end face obliquely downward. The bumper rubber attachment member 160 is a bumper formed between two leg portions 160b (acting as an outer foil supporting portion) and two leg portions 160b extending obliquely downward from the inner top panel 137a of the support top. It consists of the rubber coupling part 160a. A hole 1606 is formed in the bumper rubber coupling part 160a, and a bumper rubber 147 made of an elastic resin is inserted into the hole to contact the upper surface 151a of the support tower 151. Therefore, when the bumper rubber 147 is in contact with the upper surface 151a of the base 151, the hood outer panel 133 is closed so that both outer ends of the hood outer panel 133 are respectively bumped through the bumper rubber 147. It may be supported by the support tower 151.

In FIG. 28 taken along line 28-28 of FIG. 26, the two intermediate shock absorbing members 155 are formed of two bolts 152 and nuts 153 protruding from the upper surface 151a of the support tower 151. It is arranged on the opposite side. As in the case of the outer shock absorbing member 159, the intermediate shock absorbing member 155 is composed of an upper connecting portion 155a, two straight leg portions 155b, and a lower connecting portion 155c. In addition, the inner shock absorbing member 157 is substantially the same as the intermediate shock absorbing member 155 in shape.

The straight leg portions 155b and 157b of the intermediate shock absorbing member 155 and the inner shock absorbing member 157 both use resin (for example, gum directed resin) at their both ends or are welded to the hood outer panel. It is connected between the 133 and the base tower upper inner panel (137a). In addition, the supporting pressure upper hood inner panel 137a is provided in the vicinity of the bolt 152 and the nut 153 of the supporting tower 151 serving as the impact interference member. Therefore, the vertical gap between the support tower 151 and the hood outer panel 133 is the straight legs 155b and 157b of the middle and inner shock absorbing members 155 and 157 in the support tower 151. It can be reduced by the support tower upper hood inner panel (137a).

In addition, the straight leg portion 159b of the outer shock absorbing member 156 has both ends thereof with a resin 146 (for example, gum directed resin) or by welding, the hood outer panel 133 and the base top upper hood. It is connected between the inner panel 137a. In addition, the leg portion 160b of the bumper rubber mounting portion 160 having the bumper rubber 147 is disposed perpendicular to the base top hood inner panel 137a. Therefore, the vertical gap between the support tower 151 and the hood outer panel 133 is a straight leg portion 159b of the outer shock absorbing member 159 and the support tower upper hood inner panel 137a at the support tower 151. And, it can be reduced by the leg portion 160b of the outer shock absorbing member 159.

Hereinafter, the function of the hood structure as described above will be described with reference to FIGS. 29 and 30.

The hood 131 of this embodiment is configured to obtain an impact waveform close to the ideal shock waveform Cm that can effectively reduce the HIC value with a relatively short stroke when an impact is applied to the hood 131.

FIG. 29 shows the basic (non-improved) structure (without the shock absorber) in the impact test, and FIG. 30 shows the basic shock wave (C11) with the ideal shock wave (Cm).

Here, the hood 163 of the basic structure shown in FIG. 29 is almost the same as that shown in FIG. 24 except that the shock absorbers (ie, the shock absorbing members 155, 157 and 159) are not provided. In addition, a bolt 152 and a nut 153 are provided to face the hood outer panel 133.

In the impact test using the basic structure as shown in FIG. 29, the impact body 161 collides with the upper surface of the hood outer panel 133 at the position where the bolt 152 and the nut 153 are arranged. In addition, the acceleration and the stroke of the impact body 161 are measured. The acceleration of the impact body 161 corresponds to the action force F of the hood 163 on the longitudinal coordinates of FIG. 30, and the stroke of the impact body 161 is the stroke S on the horizontal coordinates of FIG. 30 (hood outer panel 133). Of moving distance). Based on the impact test using the basic structure shown in FIG. 29, the basic shock waveform C11 shown in FIG. 30 can be obtained.

The ideal waveform Cm can be calculated on the basis of the amount of impact energy to be absorbed in the collision as described above, and according to the HIC inference equations (1) and (2). In FIG. 30, the inner region surrounded by the ideal shock waveform Cm and the stroke S on the abscissa represents the amount of impact energy absorbed, which is defined to be equal to the amount of impact energy to be absorbed at the time of impact. All. In addition, the amount of impact energy to be absorbed in a collision can be obtained based on the impact test and calculation.

In the ideal waveform Cm shown in FIG. 30, the initial action force due to the initial deformation in the small stroke S increases rapidly and reaches the maximum action force F11 (Pm) in the stroke S11. The action force drops sharply from stroke S12 to F12. In the second half deformation after the stroke S12, since the secondary action force is generated, the reduction rate of the action force is alleviated, and the shoulder portion qm appears. Also, when the stroke reaches S13, the action force F decreases sharply, reaching approximately zero in the stroke S0, where the impact energy can be completely absorbed.

In FIG. 30, in the case of the basic shock wave C11, the initial deformation immediately after the impact is that the hood outer panel 133 locally deforms along the contour of the impact body 161, so that the initial action is mainly performed by the hood outer panel 133. It is made to increase based on tension. However, sufficient tension cannot be obtained immediately because the hood outer panel 133 is about to deform or break at both ends of the hood outer panel 133. Therefore, the rate of increase of the initial action force of the basic shock wave C11 is smaller than the ideal shock wave Cm, so the maximum action force F13 (P1) that can be obtained is smaller than the maximum action force F11 of the ideal shock wave Cm. After the action force, the hood outer panel 133 starts to deform in a wide area due to the inertia force of the impact body 161, so as the stroke S increases, the action force F suddenly decreases and the action force decreases below F12. . In addition, when the inner rib 139 interferes with the bolt 152 and the nut 153, the action force increases to F14 again and the hood 163 stops.

As described above, in the case of the basic structure of the hood 163, the initial action force is small, and the action force increases again after the stroke is further increased. As a result, the shoulder portion qm of the ideal shock waveform Cm cannot be obtained. In other words, this is undesirable for the head impact characteristic because the action force F increases again when a predetermined time elapses after the impact is started. In addition, when the hood outer panel 133 stops interfering with the bolt 152 and the nut 153, the impact energy may not be sufficiently absorbed.

On the contrary, in the case of the hood 131 of the present embodiment, the initial action force suddenly rises because the hood outer panel 133 is locally deformed along the contour of the impact body 161 at the time of initial deformation. In this case, the hood outer panel 133 deformed because the vertical gap between the hood outer panel 133 and the bolt 152 and the nut 153 is reduced by the straight leg portion 155b of the intermediate shock absorbing member 155. Since it is immediately supported by the straight leg portion 155b, deformation of the hood outer panel 133 can be suppressed immediately. Therefore, a sufficient initial action force can be obtained in a small stroke, that is, a maximum action force F11 can be obtained in the stroke S11. In addition, since the bumper rubber 146 can prevent the outer end of the hood outer panel 133 from being destroyed, the initial action force can be surely increased.

After the initial action force is obtained, the action force suddenly decreases because the hood outer panel 133 starts to deform in a wide area due to the inertia of the impactor 161. In this case, however, the hood outer panel 133 is still supported by the straight leg portion 155b of the intermediate shock absorbing member 155 and the impact force on the hood outer panel 133 is caused by the straight leg portion 155b. Since the working force F is not extremely reduced because it is distributed to the base top hood inner panel 173a, the reduction rate of the working force F is maintained at a desired value. In addition, when the stroke S reaches (S12), the action force F drops to (F12). Then, since the straight leg part 155b starts to deform | transform, a desired secondary action force arises and a shoulder part qm arises. After the straight leg portion 155b is sufficiently destroyed, the force F is again zero because sufficient impact energy can be completely absorbed before the hood outer panel 133 directly interferes with the bolt 152 and the nut 133. Suddenly decreases until the hood 163 stops.

In addition, the same function and effect can be obtained in the hood outer panel 133 on the inner and outer shock absorbing members 157 and 159.

As a result, in the present invention, since the shock waveform approximating the ideal shock waveform Cm can be obtained, the head impact characteristic can be alleviated because the HIC value can be effectively reduced in spite of the short thrust of the hood outer panel 133. .

Hereinafter, a modification of the fourth specific example of the hood structure according to the present invention will be described with reference to FIGS. 32 and 33. FIG. 32 is a plan view showing the main portion of the hood structure, and FIG. 33 is a sectional view taken along the line 33-33 of FIG.

In the present modification, the two intermediate shock absorbing members 165 are formed by punching the base top outer hood outer panel 137a, and thus are formed integrally with the bottom chip top hood outer panel 137a. As in the case of 155, each intermediate shock absorbing member 165 is composed of an upper connection portion 165a, two straight leg portions 165b, and two lower connection portions 165c, all of which are top of the pedestal upper hood. It is bent from the inner panel 137a.

In the present modified example, since the shock absorbing member 165 is formed integrally with the upper hood inner panel 137a of the base tower, the number of parts may be reduced and assembly workability may be improved.

Hereinafter, a fifth embodiment of the hood structure according to the present invention will be described with reference to FIGS. 34 and 35. A feature of this embodiment is to provide a shock absorber 171 in addition to the upper side (151a) of each base tower (151).

The shock absorber 171 is composed of an upper plate portion 181 and a plurality of straight leg (support) portions 173, 175 and 177. The upper plate portion 181 is disposed near the hood outer panel 133. Each of the straight leg portions 173, 175, and 177 is bent downward and inward from the edge portion of the upper plate portion 181 so as to extend vertically from the hood outer panel 133 side toward the support tower 151.

In addition, the upper plate portion 181 is fixed to the support tower 151 to cover the three bolts 152 and nuts 153. Three holes 179 are formed in the upper plate portion 181 to adjust the collapse force of the shock absorber 171 to a predetermined desired value. These holes 179 are preferably formed on the bolts 152 and the nuts 153 so that the shock absorber 171 can be fixed by the use of the bolts 152 and the nuts 153. In addition, the lower ends 182 and 183 of the two straight legs 173 and 175 are bent toward the bolt 172 and the nut 153, and the lower ends 182 and 183 are the shock absorbers 171. It is fixed to the upper side (151a) of the base tower 151 to fix the).

In addition, a bumper rubber 167 made of an elastic resin is attached to the outer side of the upper plate 181 to support the outer end of the closed hood outer panel 133.

In this fifth embodiment, the same functions and effects can be obtained as in the fourth embodiment.

Specifically, since the hood outer panel 133 is locally deformed along the outer shape of the impact body 161 during the initial deformation, the initial action force suddenly rises. In this case, since the deformation of the hood outer panel 133 is suppressed since the hood outer panel 133 is immediately supported by the straight legs 173, 175 and 177, sufficient initial acting force can be obtained at a small stroke, i.e., the maximum acting force ( F11) can be obtained at stroke S11. In addition, since the bumper rubber 167 can prevent the outer end of the hood outer panel 133 from being destroyed, the initial action force can be surely increased.

After the initial action force is obtained, the action force suddenly decreases because the hood outer panel 133 starts to deform deep in a wide area due to the inertia force of the impactor 161. However, in this case, since the impact force on the hood outer panel 133 is still supported by the straight legs 173, 175 and 177 of the shock absorber 171, the action force F does not suddenly decrease and the reduction rate of the action force F is reduced. This can be kept at the desired value. In addition, when the stroke S reaches (S12), the action force F drops to (F12). Thereafter, since the straight legs 173, 175 and 177 start to deform, a desired secondary action force can occur, resulting in a shoulder qm. After the straight legs 173, 175 and 177 have been sufficiently destroyed, the action force F is again restored because sufficient impact energy can be completely absorbed before the hood outer panel 133 directly interferes with the bolts 152 and 153. The hood 131 stops because it suddenly decreases to zero.

As a result, in the present invention, since the shock waveform approximating the superficial shock waveform Cm can be obtained, the HIC value can be effectively reduced despite the small stroke of the hood outer panel 133, so that the head impact characteristic can be alleviated.

In addition, since the shock absorber 171 is provided on the support tower 151, the weight of the hood 170 may be reduced, so that the hood 170 may be easily opened and closed.

In addition, since the shock absorber 172 may be fixed to the support tower 151 using the bolt 152 and the nut 153 already provided, the configuration may be simplified.

Hereinafter, a sixth specific example of the hood structure according to the present invention will be described with reference to FIGS. 36 to 38. FIG. 36 is a perspective view showing the hood structure, FIG. 37 is a sectional view taken along the line 37-37 of FIG. 36, and FIG. 38 is a sectional view showing the basic (non-improved) hood structure of this embodiment.

In FIG. 36, the hood outer panel 233 of the hood 231 closes the upper side of the engine room 235. The hood inner panel 237 is joined to the lower side 233 of the hood outer panel 233 on the engine room 235 side. The hood inner panel 237 is formed with a plurality of inner ribs 239 having a channel-shaped cross section disposed to cross each other. The inner rib 239 is composed of one elongated inner rib 239L and two short inner ribs 239S perpendicularly intersecting with the inner rib 239L.

Each inner rib 239 is deformed to absorb shocks applied to the hood outer panel 233. Each inner rib 239 includes a bottom plate 241 parallel to the hood outer panel 233, two side walls 243 bent from both sides of the bottom plate 241, and two side walls 243. And an opening 244 formed in the inner side, and two flange portions 245 bent from both ends of the two side walls 243 in both directions parallel to the hood outer panel 233. At each intersection portion 247 of the inner rib 239, the adjacent bottom plate 241 and the adjacent flange portion 245s are integrally formed on the same plane with each other. The side wall 243a is formed in a curved shape at each intersection point 247 but is deformed linearly at a position away from the intersection point 247 when viewed from the lower side 233a of the hood outer panel 233. In other words, two side straight portions 249 are formed on the side walls 243b of the respective inner ribs 239, respectively, as viewed from above.

The reinforcing plate member 251 is fixed to the upper side of the flange portion 245 on each straight portion 249 of the inner rib 239 so that the closed cross-sectional space between the reinforcing plate member 251 and the inner rib 237 ( Form N). The upper surface 245a and 251a of the flange part 245 and the reinforcement board member 251 are made of resin (for example, gum directed resin) at various positions at regular intervals as shown in FIG. Since the bottom outer surface 233a of the hood outer panel 233 is bonded, the inner rib 239 may be coupled to the hood outer panel 233.

As shown in FIG. 37, the engine 253 as the impact interfering body is disposed in the middle of the engine room 235. As shown in FIG. The inner ribs 239 are positioned away from the upper side 253a of the engine 253 so as not to interfere with the engine 253 after being deformed to absorb shocks. In other words, the distance L1 between the upper surface 253a of the engine 253 and the lower surface 239a of the inner rib 239 is smaller than the stroke S0 of the ideal shock waveform Cm shown in FIG. Largely determined.

Hereinafter, the function of this embodiment will be described.

In this embodiment, the head impact characteristics of the hood on the inner rib 239 can be mitigated without interference between the inner rib 239 and the engine 253, ie in the hood 231 on the inner rib 239. The HIC value can be reduced. In other words, the hood 231 is configured such that a shock waveform close to the ideal shock waveform Cm can be obtained.

FIG. 38 shows the basic (non-improved) hood structure for impact testing, and FIG. 39 shows the basic shock waveforms C21 and C22 along with the ideal shock waveform Cm.

The basic hood structure shown in FIG. 38 is the same as the embodiment shown in FIGS. 36 and 37 except that the reinforcing plate member 251 is not disposed. Therefore, the upper surface 245a of the flange portion 245 of the inner rib 239 is joined to the lower surface 233a of the hood outer panel 233 at regular intervals.

In the impact test using the basic structure shown in FIG. 38, the impact body 255 has a position P above the intersection point 247 of the inner rib 239 and a straight portion 249 of the inner rib 239, respectively. In the above position Q, the upper surface of the hood outer panel 233 collides, and the acceleration and the stroke of the impact body 255 are measured. The acceleration of the impactor 255 corresponds to the action force of the hood 259 on the longitudinal coordinates of FIG. 39, and the stroke of the impactor 255 is the stroke S on the horizontal coordinates of FIG. 39 (moving distance of the hood outer panel 233). ) Based on the impact test using the basic structure shown in FIG. 38, the basic shock waveforms C21 and C22 shown in FIG. 39 can be obtained. The basic shock waveform C2l at the impact position P is shown by the broken line in FIG. 39, and the basic shock waveform C22 at the impact position Q is shown by the dotted line.

The ideal shock waveform Cm is a relationship between the action force and the stroke (moving distance) of the hood outer panel 233 of the hood structure, thereby reducing the hood stroke and the HIC value. The ideal shock waveform Cm can be obtained on the basis of the amount of impact energy to be absorbed at the time of impact as described above and according to the HIC inference equations (1) and (2). In FIG. 39, the inner region A2l surrounded by the ideal shock waveform Cm and the stroke S on the abscissa represents the amount of impact energy absorbed, and this inner region A2l is the impact to be absorbed in the collision. It is determined to be equal to the amount of energy. In addition, the amount of impact energy to be absorbed in a collision can be obtained based on the impact test and calculation.

In the ideal shock waveform Cm shown in FIG. 30, the initial action force due to the initial deformation rapidly increases in the small stroke S to reach the maximum action force F21 (pm) in the stroke S21. However, the action force drops sharply from stroke S22 to F22. In the second half deformation after the stroke S22, since the secondary action force is generated, the reduction rate of the action force is alleviated and a shoulder portion qm may be generated. In addition, when the stroke reaches S23, the action force F suddenly decreases to reach approximately zero in the stroke S0 at which time the impact energy can be completely absorbed.

Referring to Fig. 38, the basic shock waveform at position P will be described. Since the hood outer panel 233 is locally deformed along the contour of the impact body 255 at the initial deformation immediately after the impact, the additional working force increases rapidly based on the tension of the hood outer panel 233 so that the maximum working force (F2l) ( P2l). After the maximum working force F2l, the hood outer panel 233 starts to deform deeply in a wide area by the inertia force of the impactor 255, so the working force F suddenly decreases as the stroke S increases, so the working force Decrease from stroke S22 to F22. Further, since the inner rib 239 is greatly deformed and broken after the stroke S22, a preferable secondary action force may occur, so that the shoulder portion q21 (here, the reduction rate of the action force F is alleviated) is produced. In addition, when the inner rib 239 is completely destroyed, since the impact energy can be completely absorbed before the inner rib 239 interferes with the engine 253, the working force F is suddenly reduced to zero again and the hood stops. . As described above, at the position P, a shock waveform approximating the ideal shock waveform Cm can be obtained.

On the other hand, in the case of the basic shock waveform C22 at the position Q, as in the case of the basic shock waveform C21, the acting force F suddenly decreases after the maximum acting force F21, but the acting force F is reduced to (F22). After reaching the force (F) decreases to (F23) below (F22).

Therefore, the reduction rate of the working force differs greatly from the reduction rate of the ideal shock waveform Cm. In other words, the shoulder portion q22 of the basic shock waveform C22 is lower than the shoulder portion of the ideal shock waveform Cm.

The reason for the difference between the two positions P and Q is that the strains of the side walls 243 of the respective inner ribs 239 are different from each other. More specifically, since the intersecting side walls 243 of the respective inner ribs 237 are bent at the position P, the side walls 243 easily deform outward at the time of a collision, so that the inner ribs 239 reliably deform. Therefore, high secondary force may occur. On the other hand, since the side wall 243 of each inner rib 237 is formed straight at the position (Q), the high side action force cannot be generated because the side wall 243 is easily deformed outward during the collision.

As described above, a sufficient amount of absorbed impact energy can be obtained because the inner region of the basic shock waveform C22 is reduced when the secondary working force is insufficient and the shoulder portion is smaller than the secondary working force of the ideal shock waveform Cm. As a result, since the lower side 239a of the inner side rib 239 collides with the upper side 253a of the engine 253, the inner side rib 239 is deformed and broken to absorb impact energy. Therefore, as shown by r22 in FIG. 39, the action force increases again after a relatively long time after the impact.

In contrast, in the present invention, since the reinforcing plate member 251 is provided at the straight portion 249 of the inner rib 239 as shown, a closed end surface N is formed at each intersection. Therefore, the inner rib 239 can be deformed certainly because the side wall 243b of the inner rib 239 is not easily deformed outward due to the deformation of the hood 231 at the straight portion 249 of the inner rib 239. Since the desired secondary action force is generated, the desired shoulder portion (qm) may occur. As a result, since the impact energy can be completely absorbed before the inner rib 239 is completely destroyed and interferes with the engine 253, the impact waveform C2l close to the ideal shock waveform Cm can be obtained.

That is, when an impact is applied to the straight portion 249 (position Q) of the hood 231, the hood outer panel 233 is locally deformed along the outer shape of the impact body 255 at the initial deformation, and thus the stroke S22. The initial action force suddenly increases to the maximum action force (F1) at. After the maximum action force F1, the force force F suddenly decreases to F22 in the stroke S22 because the hood outer panel 233 starts to deform in a wide area due to the inertia force of the impactor 255. Thereafter, since the reinforcement plate member 251 of the hood inner rib 239 starts to deform, a desired secondary action force is reliably generated, so that a shoulder portion qm may occur. When the inner rib 239 is sufficiently destroyed, the action force F decreases back to zero again because impact energy can be completely absorbed before the inner rib 239 interferes with the engine 253.

Therefore, in the present invention, since the shock waveform C21 approximating the ideal shock waveform Cm can be obtained, the head impact characteristic can be alleviated by effectively reducing the HIC value even in a short stroke.

On the other hand, when an impact is applied to the intersection portion 247 (position P), the shock wave C22 is generally the same as the ideal shock wave Cm even though the reinforcing plate member 251 is not provided.

As described above, in the sixth embodiment, since two adjacent sidewalls 243a of the inner rib 239 are connected to each other along the curved shape and become stronger, on the intersection portion 247 (position P) of the inner rib 239. In the hood outer panel 23, a shock wave C2l approximating the ideal shock wave Cm can be obtained. On the other hand, since the reinforcing plate member 251 is provided and strengthened, a shock waveform close to the ideal shock waveform Cm is also obtained at the hood outer panel 233 on the straight portion 249 (position Q) of the inner rib 239. Can be. In summary, at any position (P) or (Q) of the inner rib 239, that is, the hood outer panel 233, an impact waveform close to the ideal shock waveform can be obtained.

Hereinafter, a seventh specific example of the hood structure according to the present invention will be described with reference to FIGS. 40 to 42. 40 is a perspective view showing the hood structure of this embodiment, FIG. 41 is a sectional view taken along the line 41-41 of FIG. 40, and FIG. 42 is a sectional view showing the basic (non-improved) hood structure of this embodiment.

A feature of this embodiment is to increase the secondary action by forming a closed cross section in the inner rib 239 without providing the reinforcing plate member 251 of the sixth embodiment.

More specifically, as shown in FIGS. 40 and 41, the inner ribs 239 are joined to the hood outer panel 233 to form a closed satin N therebetween. That is, the entire upper side of the flange portion 245 of the inner rib 239 is joined to the lower side 233a of the hood outer panel 233 (without joining at various positions at regular intervals). The used binder is, for example, an elastic gum frankincense resin.

In addition, the engine 253 is disposed in the middle of the engine room 235 as an impact interfering body, but at a position L1 from the upper surface 253a of the engine 253 so as not to interfere with the engine 253 after the shock absorption. Inner rib 239 is provided. The distance L1 between the lower side 239b of the inner rib 239 and the upper side 253a of the engine 253 is determined to be larger than the stroke S0 of the ideal shock waveform Cm as in the sixth embodiment. do.

The function of the seventh specific example will be described below.

FIG. 42 shows the basic hood structure (point junction) for impact testing, and FIG. 43 shows the basic shock waveform (C23) together with the ideal shock waveform (Cm).

Here, the basic hood structure shown in FIG. 42 is the same as that of the sixth embodiment shown in FIG. 38, but the structure and material of the hood outer panel 233, hood inner panel 237 and inner rib 239 are different from each other. Therefore, the impact test results are different even if the same impact test is performed as in the sixth embodiment. The shock waveform C23 obtained by the seventh embodiment is shown by the broken line in FIG. 43 together with the ideal shock waveform Cm.

In the basic shock waveform (C23), the action force (F) suddenly decreases after the maximum action force (F2l), almost as in the case of the ideal shock wave (Cm), but after the action force (F) reaches (F22), the action force (F) This is not relaxed and decreases linearly to zero as indicated by q23. Therefore, the reduction rate of the force is greatly different from the ideal shock wave (Cm). In other words, the shoulder portion qm of the ideal shock waveform Cm does not occur.

As described above, since the inner portion of the basic shock waveform C23 is small because no shoulder portion is generated, a sufficient amount of absorbed impact energy cannot be obtained. As a result, the inner rib 239 collides with the upper surface 253a of the engine 253, so the inner rib 239 is deformed and broken to absorb impact energy. Therefore, as shown by (r23) in FIG. 43, after a relatively long time elapses after the collision, the action force increases again.

The reason why sufficient absorbed impact energy cannot be obtained is because in the case of the basic structure shown in FIG. 42, the hood is opened because the space between the hood outer panel 233 and the hood inner panel 235 (inner rib 239) is opened. This is because the inner rib 239 is not deformed together with the deformed hood outer panel 233 even if the outer panel 233 is greatly deformed.

In contrast, in this embodiment, the inner rib 239 is joined to the hood outer panel 233 over the entire surface of the flange portion 245 of the inner rib 239 to form a closed space N therebetween. Therefore, when the hood outer panel 233 is greatly deformed, the side wall 243b of the inner rib 239 does not open outward, so the inner rib 239 is deformed with the hood outer panel 233. Therefore, the desired secondary action force is generated and thus a desirable shoulder qm can be produced. As a result, the impact energy can be completely absorbed before the inner rib 239 is completely destroyed and interferes with the engine 253, so that an impact waveform close to the ideal shock waveform Cm can be obtained.

That is, when the impact is applied to the hood 261, the hood outer panel 233 is locally deformed along the contour of the impact body 255 at the initial deformation, so that the initial acting force in the stroke S21 is up to the maximum working force F2l. Suddenly increases After the maximum action force F2l, the action force F suddenly decreases from stroke S22 to F22 because the hood outer panel 233 starts to deform in a wide area due to the inertia force of the impactor 255. Thereafter, since the hood inner rib 239 starts to deform, the desired secondary action force can be reliably generated, and thus a shoulder qm can occur. When the inner rib 239 is sufficiently broken, the working force F is rapidly reduced to zero again because the impact energy can be completely absorbed before the inner rib 239 interferes with the engine 253. Therefore, in the present invention, since the shock waveform approximating the ideal shock waveform Cm can be obtained, the head impact characteristic can be alleviated by effectively reducing the HIC value even in a short stroke.

As described above, in the seventh embodiment, since the inner ribs 239 are bonded to the hood outer panel 233 over the entire surface of the inner ribs 239, the secondary action force is reliably increased, so that the shock waveform is the ideal shock waveform ( Approximate to Cm).

In addition, even when the secondary action force at the straight portion 249 of the inner rib 239 is not sufficient as the secondary action force at the intersection portion 247 of the inner rib 239, the secondary action force is increased only at the straight portion 247. In order to provide the reinforcing plate member 251 to the straight portion 247.

Hereinafter, an eighth embodiment of the hood structure according to the present invention will be described with reference to FIGS. 44 to 46. FIG. 44 is a plan view showing the hood structure, FIG. 45 is a sectional view taken along the line 45-45 of FIG. 44, and FIG. 46 is a sectional view taken along the line 46-46 of FIG.

A feature of the hood structure 265 of this embodiment is to interfere with the engine 253 the inner ribs 239A covered with the hard brittle member 267 to increase secondary action.

44 to 46, a plurality of inner ribs 239 are formed in the inner panel 37. The outer surface of the straight inner rib 239A (one of the plurality of inner ribs 239) extending over the engine 253 is a hard home member 267 to increase the action of the inner rib 239A upon initial deformation. Covered with The hard brittle member 267 is made of hard resin or hard resin covered with a rapid thin film and bonded to the outer surface of the inner rib 239A of the channel-shaped cross section. In addition, both ends 267a of the hard brittle member 267 are joined to the inner surface of the hood outer panel 233. Both side walls 243 of the inner ribs 239A have a plurality of vertically extending vertically as shown in FIG. 46 to make the inner ribs 239A easily deform and break, i.e., to reduce the collapse force of the side walls 243. Slot 269 is formed. In addition, the collapse force of the side wall 243 can be freely adjusted according to the number, shape, and size of the vertical slots 269.

The entire upper surface 245a of the two flange portions 245 of the hard brittle member 267 is formed by the resin 263 (for example, an elastic gum directed resin), and the lower surface of the hood outer panel 233 ( 233a) to form a closed space therebetween.

The height position of the lower side 267b of the hard brittle member 267 is determined to interfere with the upper side 253a of the engine 253 at the end of the deformation of the hood outer panel 233 at the time of impact. In other words, the gap distance L2 between the upper surface 253a of the engine 253 and the lower surface 267b of the hard brittle member 267 is the stroke S0 of the ideal shock waveform Cm shown in FIG. Is determined to be smaller than

When interfering with the upper surface 253a of the engine 253, the hard brittle member 267 breaks down as shown in FIG. 49 after generating a predetermined action force. In addition, after the hard brittle member 267 is broken down as shown in FIG. 49, the inner rib 239A is greatly deformed by interference with the engine 253. FIG.

The function of the eighth embodiment will be described below.

FIG. 47 shows the basic hood structure without the hard brittle member 267 for impact testing, and FIG. 48 shows the basic shock waveform C24 along with the ideal shock waveform Cm.

Here, the basic hood structure of the eighth embodiment shown in FIG. 47 is almost the same as that of the sixth embodiment shown in FIG. 38, but the inner ribs (in the material of the hood outer panel 233 and the inner panel 237) The difference between the basic hood structure of both in the dimensions and material of 239A and in the gap distance L3L2 between the lower surface 239a of the inner rib 239A and the upper surface 253a of the engine 253. Even if the same impact test is carried out as in the sixth embodiment, the impact test results are different. The shock waveform C24 obtained by the seventh embodiment is shown in dashed lines along with the ideal shock waveform Cm in FIG.

Compared with the ideal shock waveform Cm, in the case of the basic shock waveform C24, the initial force of the hood outer panel 233 is slightly smaller, and the maximum force F23 and P24 and the force after maximum force F24. Even all are small. In addition, in the latter deformation of the hood outer panel 233, since the inner ribs 239A gradually start to deform, the action force increases slightly, and when the inner ribs 239A interfere with the engine 253, the inner ribs 239A are affected. The force F rapidly increases due to strain breakage (r24). Therefore, the basic shock waveform C24 is significantly different from the ideal shock waveform Cm. The reason for this is as follows. In the hood 262 of the basic structure, the shoulder qm is not generated because the initial action force is slightly small and greatly drops in the second half of the initial deformation. In addition, since the interference with the engine 253 starts later, the action force F suddenly increases after the stroke S exceeds (S0) r24. As a result, the action force F rises after a relatively long time elapses after the impact.

In contrast, in the hood 265 of this embodiment as shown in FIG. 45 and FIG. 46, the hood outer panel 233 is initially started because the surface of the inner rib 239A is covered with the hard brittle member 267. Since the hard brittle member 267 suppresses the deformation rate of the hood outer panel 233 when the depth starts to deform, it is possible to obtain a higher initial action force than the basic structure. In this deformation, since the entire surface of the inner rib 239A is joined to the hood outer panel 233, the strain rate of the hood outer panel 233 can be surely reduced.

Thereafter, when the hard brittle member 267 starts to interfere with the upper surface of the engine 253, a secondary action force is generated first, but then the hard brittle member 267 is broken as shown in FIG. 49. Since the inner ribs 239A are largely deformed and broken, the secondary action force is reduced. In this case, since the gap between the inner rib 239A and the engine 253 is determined by a predetermined distance L2, the secondary action force can be obtained from the stroke S22 as in the ideal shock waveform Cm. In addition, since the collapse force of the inner rib 239A itself can be determined to a desired value according to the number and size of the slits 269, the secondary action force can be reduced to a predetermined reduction rate.

Therefore, when the impact is applied to the hood 265 in the impact test of the hood 265 of the present embodiment, the initial action force is reduced because the hood outer panel 233 is locally deformed along the contour of the impact body 255 at the initial deformation. Suddenly increases In this case, since the initial action force is increased by the hard brittle member 267, the initial action force suddenly increases to the maximum action force F2l at the stroke S21. After the maximum working force F2l, since the hood outer panel 233 starts to deform in a wide area due to the inertia force of the impactor 255, the working force F suddenly decreases to F22 in the stroke S22. Thereafter, the secondary brittle force may occur because the hard brittle member 267 interferes with the upper surface 253a of the engine 253.

In addition, since the inner rib 239A greatly deforms when the hard brittle member 267 is broken as shown in FIG. 49, the secondary acting force is reduced, so that a desired secondary acting force may occur and a shoulder may be generated. After that, when the inner rib 239A is sufficiently destroyed, the impact energy is sufficiently absorbed, so the action force suddenly decreases to zero again. Therefore, in this embodiment, since the shock waveform approximating the ideal shock waveform Cm can be obtained, the head impact characteristic can be alleviated by effectively reducing the HIC value even in a short stroke.

As described above, in the eighth embodiment, since the inner ribs 239A are covered with the hard brittle member 267, the secondary action force can be reliably increased to approximate the shock waveform to the ideal shock waveform Cm.

In addition, in the eighth embodiment, the inner rib of the rectangular cross section (channel type) has been described, but as shown in FIGS. 50a and 50b, it is formed in a ladder shape (hat shape) or a triangle and covered with a hard brittle member 267. The same effect as above can be obtained using the true inner rib 239a.

Further, although the distance between the hood outer panel 233 and the engine 253 is not the same as in the case of the hood 273 shown in FIG. 51, the lower side 267a of the hard brittle member 267 and the engine ( If the inner rib 239A is formed so that the distance L4 between the upper surface 253a of the 253 is set to a predetermined value, the same effect as described above can be obtained.

Hereinafter, a ninth embodiment of the present invention will be described, where the basic concept of the present invention is applied to a fender structure of a motor vehicle.

52 and 53 show a comparison fender structure, with FIG. 53 being a cross sectional view taken along line 53-53 of FIG.

As illustrated, in the comparison fender structure, a vertical wall 1101 having an upper protrusion 1110 and a step FA is formed on an upper edge portion of the fender 1100. In addition, the joint flange portion 1102 formed at the lower end of the vertical wall 1101 is coupled to the hood ridge reinforcement portion 1200 provided on both sides of the front of the vehicle to extend in the front and rear of the vehicle. In addition, in FIG. 53, reference numeral 1201 denotes a hood ridge upper side coupled to the hood ridge reinforcement 1200 to form a closed cross section, and 1300 denotes a support housing coupled to the closed cross-sectional structure. 1400 represents a hood for opening and closing the engine compartment.

In the comparative fender structure as described above, when the head impactor collides with the outer surface near the upper protrusion 1110 of the fender 1100, the vertical wall 1101 starts from the step FA at the initial deformation. Since the fender 1100 near the upper protrusion 1110 is deformed and deformed so as to protrude toward the hood ridge reinforcement 1200, the converted portion of the fender 1100 collides with the hood ridge reinforcement 1200. Because it is further deformed.

As described above, in the comparison fender structure, an appropriate fracture shape of the fender 1100 is determined based on the step FA formed in the vertical wall 1101. However, even if the impact energy is absorbed as described above, the head impact characteristic of the fender 1100 is not necessarily alleviated due to the reason described with reference to FIG. 2.

Accordingly, the ninth embodiment provides a fender structure capable of absorbing the impact energy by effectively reducing the HIC value even in a short deformation stroke to reduce the head impact characteristic.

54 and 55 illustrate a fender structure according to the present embodiment. 54 is a cross-sectional view taken along the line 53 of FIG. 55 is a plan view showing the fender 1100 and the hood 1400, and the bumper 1500 is also shown.

A feature of the ninth embodiment is to provide the synthetic resin layer 1002 on the inner side of the step FA of the vertical wall 1101 of the fender 1100, and to the flat portion 1200a of the hood ridge reinforcement 1200. A recess 1003 is formed. The other structure is basically the same as the case of the comparison structure shown in FIG. 53, and therefore the same number is maintained for similar parts having the same function.

In the fender structure 1001 of this embodiment, similar to the comparative example, the vertical wall 1101 is formed on the upper edge portion of the fender 1100 and the upper protrusion 1110 is formed on the upper side of the vertical wall 1101. However, the synthetic resin layer is further attached (attached in the molten state) to the step FA of the vertical wall 1101 of the fender 1100 in such a manner as to extend the entire length of the fender 1100 back and forth. In addition, the flat portion 1200a of the hood ridge reinforcement portion 1200 is formed with a recess portion 1003 at a position corresponding to the synthetic resin layer 1002.

More specifically, in FIG. 54, the synthetic resin layer 1002 has one end portion 1002a extending from an upper corner of the upper protrusion 1110 to an upper step portion FA1 of the step portion FA and having the other end portion ( The inside of the fender 1100 in such a manner that 1002b extends downward along the fender 1100 from the same upper corner of the upper protrusion 1110 to cover the flat portion 1200a of the hood ridge reinforcement 1200 from above. It is attached to the side. Further, the concave portion 1003 is formed over the entire length of the planar portion 1200a of the hood ridge reinforcement portion 1200 so as to correspond to the position of the synthetic resin layer 1002. In addition, the concave portion 1003 may be formed to have a width and a depth that can be accommodated when the upper protrusion 1110 of the fender 1100 is deformed and broken.

The fender structure of this embodiment is configured to reduce the HIC value even at a small stroke by obtaining a shock waveform Ca approximating the ideal shock waveform Cm in the impact test.

In FIG. 56, the shock wave Ca (Cm) of this embodiment is shown by the dashed line, and the basic (non-improved) shock wave (Cb) is shown by the solid line.

In the impact test, the gravity center of the impact body FM collides with the upper projection 1110 of the fender 1100 of the comparative fender structure as shown in FIGS. 57A to 59A. The stroke (traveling distance) is measured. The measured acceleration and the stroke of the impact body FM correspond to the average working force F and the deformation stroke S shown in FIG. 56, so that the basic shock waveform Cb shown in FIG. 56 is obtained by the impact test. Can lose.

Hereinafter, the basic shock waveform Cb will be described in more detail according to the impact stage of the impact body FM and the deformation of the fender 1100 with reference to FIGS. 57A to 59B.

As shown in FIGS. 57A and 57B, the upper waveform 1110 is not yet deformed under the condition that the impact body FM contacts the upper protrusion 1110 of the fender 1100, and thus the basic waveform b is The average working force F and the stroke S both become zero at the point b1.

However, as shown in FIGS. 58A and 57B, when the impactor FM collides with the upper protrusion 1110 of the fender 1100, the upper protrusion 1110 is deformed (inverted), i.e., hooded. Since it starts to deform to protrude toward the plane portion 1200a of the ridge reinforcement portion 1200, the converted portion FB reaches the plane portion 1200a. This initial deformation step is represented by Sa in FIG. The fundamental waveform Cb reaches the point b2 when the end portion of the switching portion FB reaches the planar portion 1200a. During the initial deformation Sa of the first half, the fender 1100 is relatively deformed due to the presence of the step FA, so that the average working force is relatively high.

As shown in FIGS. 59A and 59B, when the upper protrusion 1110 of the fender 1100 is further deformed, the planar portion 1200a of the hood ridge reinforcement portion 1200 is the switching portion FB of the fender 1100. Is deformed into a concave shape by an end portion. The deformation step of this latter part is shown by (Sb) in FIG. In addition, the point where the end of the switching portion FB starts to deform the planar portion 1200a of the hood ridge reinforcement 1200 is indicated by the point b4 in FIG.

Since the upper protrusion 1110 is deformed as the deformed bottom is in contact with the plane portion 1200a in the deformation step Sb of the latter half, the average working force F of the fender 1100 is changed by the plane portion 1200a. The maximum is reached at the starting point b3 but after the point b3 abruptly decreases to the final strain point b4. As described above, the fundamental waveform Cb can be obtained.

In the case of the basic structure, the amount of impact energy absorbed corresponds to the area surrounded by the basic shock waveform Cb and the stroke S (abscissa).

On the other hand, in the ideal shock waveform Cm obtained by the calculations of the HIC inference equations (1) and (2), the amount of impact energy absorbed is the same as that of the basic structure, but the HIC value is small.

In the shock waveform Ca as shown by the dashed line in FIG. 56, the average force F of the fender is higher at the peak a1 of the initial strain Sa compared to the point b2 of the basic shock waveform Cb, but the strain In Sb, it is low due to the shoulder a2. Further, the deformation stroke of the fender of the ideal shock waveform Cm is longer than the deformation stroke of the basic shock waveform b by (ds).

The ideal shock waveform (Cm) represents how the basic structure of the fender is designed to reduce head impact characteristics even at small strokes of the fender. Therefore, the fender structure of this embodiment is constructed based on this design concept.

As already explained, in order to approach the basic shock waveform Cb to the ideal shock waveform Cm, a synthetic resin layer 1002 is additionally provided to increase the average working force F at the initial deformation Sa and further follow-up. Further concave portions 1003 are formed to reduce the mean effort force F at strain Sb and to increase the deformation stroke S at the subsequent strain Sb.

Hereinafter, the shock waveform Ca approximating the ideal shock waveform Cm of the present embodiment will be described in more detail according to the impact stage of the impact body FM and the deformation of the fender 1100 with reference to FIGS. 60A to 62B.

60A and 60B, in the state in which the impact body FM is in contact with the upper protrusion 1110 of the fender 1100, the upper protrusion 1110 is not deformed yet, so the shock wave Ca may be The average working force F and the stroke S both become zero at the point b1.

However, as shown in FIGS. 61A and 61B, when the impact body FM collides with the upper protrusion 1110 of the fender 1100, the upper protrusion 1110 is deformed (inverted), i.e., hooded. The deformed portion FB reaches the planar portion 1200a because it begins to deform to protrude toward the planar portion 1200a of the ridge reinforcement 1200. In this deformation step, since the synthetic resin layer 1002 is additionally attached to the stepped portion FC of the upper protrusion 1110, a high average working force F can be obtained in comparison with the basic structure without changing the basic breakdown form. A peak close to the peak a1 of the impact waveform Cm can be obtained.

The upper protrusion 1110 of the fender 1100 is further modified as shown in FIGS. 62a and 62b. However, in this case, since the concave portion 1003 is formed in the planar portion 1200a of the hood ridge reinforcement portion 1200, the switching portion FC is deformed into the concave portion 1200a. In this state, the bottom of the upper protrusion 1110 is not in contact with the hood ridge reinforcement portion 1200, so that the average working force can be reduced compared to the basic structure. In addition, the deformation stroke S can be increased in comparison with the basic structure. Accordingly, the shoulder portion a2 may occur in the subsequent deformation Sb and the deformation stroke may be increased by dS, thereby obtaining a shock wave Ca that is close to the ideal shock wave Cm.

Hereinafter, a ninth embodiment of the present invention will be described with reference to FIG. In the ninth embodiment shown in FIG. 54, the synthetic resin layer 1002 has one end portion 1002a extending from the upper corner of the upper protrusion 1110 to the upper step portion FA1 of the step portion FA. The fender 1100 in such a manner that the end portion 1002b extends somewhat downward along the fender 1100 from the same upper corner of the upper protrusion 1110 to cover the flat portion 1200a of the hood ridge reinforcement 1200 from above. It is attached to the inner side of the. However, in this modification, the synthetic resin layer 1002 is attached to the inner side of the fender 1100 so that the entire step FA is covered with the resin layer 1002.

That is, as shown in FIG. 63, one end portion 1002a of the resin layer 1002 extends from the upper corner of the upper protrusion 1110 to the lower step portion FA2 of the step portion FA and the other end portion 1002b. ) Extends somewhat downward along the fender 1100 from the same upper corner of the upper protrusion 1110 to cover the flat portion 1200a of the hood ridge reinforcement 1200 from above. Other fender structures are the same as those of the ninth embodiment shown in FIG.

In this embodiment, the action force at the time of initial deformation can be increased so that the shock waveform Ca can be more closely approximated to the ideal shock waveform Cm.

It is also preferable to change the thickness of the synthetic resin layer 1002 thinly on the front side of the vehicle body and thickly on the rear side. In general, the impact force is relatively small when the head impact of a pedestrian (eg a child) is applied to the front side of the vehicle. On the other hand, the impact force is relatively large when the head shock of a pedestrian (for example, an adult) is applied to the rear side of the vehicle. Therefore, when the thickness of the resin layer 1002 is gradually adjusted, the average working force can be increased in accordance with the magnitude of the head impact applied to the fender.

As described above, in the hood structure according to the present invention, since the shock absorber starts to interfere with the shock interfering body (engine or support tower) when the hood moves by a predetermined stroke, the shock absorber is deformed and destroyed, thus providing an ideal shock energy absorption waveform. The desired secondary action force required for (Cm) can be generated. Therefore, the impact energy can be absorbed under ideal absorption conditions, and as a result, the HIC value (head impact characteristic) can be reduced in a small stroke of the hood.

Further, in the fender structure according to the present invention, since the shock absorber (resin layer) starts to deform when the fender moves by a predetermined stroke, a desired secondary action force necessary for the ideal shock energy absorption waveform Cm may be generated. Therefore, the impact energy can be absorbed under ideal absorption conditions, and as a result, the HIC value (head impact characteristic) can be reduced even in the stroke of the smallest hood.

Claims (6)

The fender panel 1100, which is bent from the upper protrusion 1110, is formed with a vertical wall 1101 on which a step FA is formed so as to be easily broken, and to absorb the impact applied to the fender during deformation. A hood ridge reinforcing member 1200 for stopping the deformed reinforcing layer having a reinforcing layer 1002 disposed on the upper protrusion 1110 and a concave portion 1003 for receiving the deformed reinforcing layer 1002. The impact energy absorption rate of the reinforcing layer is determined so that the impact energy generated during collision can be absorbed according to the ideal impact energy absorption waveform in order to effectively reduce the head impact criterion at the shortest stroke of the fender panel. Fender structure of a vehicle for absorbing the impact applied to the fender of the vehicle in the event of a collision. The method of claim 1, wherein the ideal impact energy absorption waveform is an ideal relationship between the acting force and the stroke of the deformed fender, and is calculated based on the amount of impact energy that must be absorbed at the time of collision and according to the following head shock criteria analogy. And the reinforcement layer is deformed at a relatively appropriate energy absorption rate in the collision to generate the secondary force required for the ideal impact energy absorption waveform. Where HIC is the head impact criterion, a (t) is the acceleration at the center of gravity of the test impact body, t1 and t2 are the predetermined time (0t1t2) the acceleration is applied, Represents the maximum value selected from [a ₁₂ ^2.5 (t2-tl)]. The fender structure of claim 1, wherein the reinforcing layer is a synthetic resin layer (1002), and the synthetic resin layer is attached on an inner side surface of the step portion FA of the vertical wall 1101. The fender structure of claim 3, wherein the synthetic resin layer (1002) covers approximately half of the step (FA) of the vertical force (1101). 4. The fender structure of an automobile according to claim 3, wherein the synthetic resin layer (1002) covers the entire surface of the step (FA) of the vertical wall (1101). 4. The fender structure of claim 3, wherein the thickness of the synthetic resin layer (1002) is thin at the front side of the vehicle and thick at the rear side.