JP3120657B2 - Car body superstructure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upper structure of a vehicle body, and more particularly, to a structure in which a head impactor receives an impact from a hood.

[0002]

2. Description of the Related Art A conventional hood structure of this kind of automobile is shown in FIGS. 24 to 26 (see Japanese Utility Model Laid-Open No. 61-26882). FIG. 24 is a perspective view showing a conventional automobile having an upper body structure, FIG. 25 is an enlarged view of a main part of FIG. 24, and FIG.
FIG. 5 is a sectional view taken along line VV of FIG.

As shown in FIG. 24, an inner panel 7 is provided below the hood outer panel 3 of the hood 1 (on the engine room 5 side). The inner panel 7 has a frame 9 and an inner rib 11 located inside the frame 9 to reinforce the frame 9. Both sides of the frame 9 at the rear of the vehicle body are rotatably supported by the vehicle body via hood hinges 13. The engine 15 is disposed in the engine room 5, and a flat plate portion 17 is provided between the inner ribs 11 located above the vehicle body of the engine 15 as shown in FIG. 25. The flat plate portion 17 is provided with a plurality of cut-and-raised pieces 19 cut and raised to face the engine 15. As shown in FIG. 26, each cut-and-raised piece 19 is formed in a substantially arc-shaped cross section, and both ends 21 are continuous with the flat plate portion 17.

According to such a hood structure, when the pedestrian's head hits the outer surface of the hood outer panel 3, the hood outer panel 3 and the inner rib 11 are deformed so as to protrude toward the engine room 5, and the cut-and-raised piece 19 is further bent. And is crushed and deformed. That is,
The amount of energy absorbed by the hood 1 above the vehicle body of the engine 15 is increased by cutting and raising the piece 19 to reduce the moving distance of the hood 1 to secure the required amount of energy absorption.

[0005]

However, even if the amount of energy absorbed by the hood 1 is secured in this way, the hood 1
Is not always mitigated.

Experimental data on head impact resistance includes a WSTC (Wayne State Tolerace Curve) shown in FIG.
ve) is known ("Automobile Engineering Handbook <Part 3>" issued by the Japan Society of Automotive Engineers of Japan (September 3, 1983)
(0st edition, first edition), page 2-30, and "Automotive Engineering, Vol. 16, Automobile Safety", published by Sankaido Co., Ltd. (March 20, 1980, first edition, page 201-203).

The effective acceleration used as a parameter of the WSTC is the average acceleration (the integral value of the acceleration waveform divided by the operation time), and corresponds to the average reaction force applied to the head in the event of a collision. .

According to the WSTC, even if the average reaction force received by the head impactor is small to some extent (effective acceleration = G1
), If the duration becomes longer (duration> T1), the danger area is reached, and conversely, even if the average reaction force is large (effective acceleration =
G2), if the duration is extremely short (duration <T2), it does not reach the danger zone and belongs to the safety zone.

That is, head impact resistance is determined by both factors of acceleration and action time. If the amount of energy absorption is large, head impact resistance is not necessarily lowered, and the initial reaction force at impact is reduced. In some cases, a sudden rise to some extent within a predetermined period of time may lower the head impact value than maintain a not so high reaction force for a long time.

Further, WSTC is experimental data under linear acceleration, and the actual impact received when the head impactor (head impactor) collides with the hood 1 shows not a linear acceleration but a complicated acceleration waveform. WST on actual impact
C cannot be applied directly. For this reason, HIC, which is one of the failure reference values, is used as a method for evaluating safety based on the WSTC based on the results of impact experiments using an impactor.
A method using a value (Head Injury Criterion) is known.

The HIC value is calculated by the following equation.

(Equation 1)

(Equation 2) Is calculated according to T1 and t2 in both equations are 0 <t1 <
t2 is an arbitrary time during the acceleration action, and a (t) is the acceleration at the center of gravity of the head of the impactor. As for the HIC value, the smaller the value is, the higher the security is. Generally, HIC = 1000
Is considered a safety limit.

According to the equation, HIC values, the average acceleration a ₁₂ at the working time from any t1 to t2 2.5
It is calculated as the maximum value of the value obtained by multiplying the power value by the operation time (t2-t1). That, HIC value in principle if the impact behavior (acceleration waveform) differences also differ, an average acceleration a ₁₂ and its action time (t2 -t1) is a factor that determines the magnitude of the HIC value. The relationship between the average acceleration a ₁₂ and its action time (t2 -t1) can be replaced with the relationship of the reaction force and the movement distance of the hood 1 of the hood 1, the reaction force of the hood 1 and also by the movement distance , HIC values are determined.

[0013] As a result, the fact that the amount of impact energy absorbed is large does not mean that the HIC value is uniformly reduced, but there are many cases where the HIC value differs even if the energy absorption amount is the same. Further, even if the HIC value at a certain point of the hood 1 becomes a low value, the HIC value may show a high value at another point outside the one point.

Accordingly, as shown in FIG. 24, in the conventional structure, the rise of the crushing reaction force of the cut-and-raised piece 19 formed in a substantially arc-shaped cross section is delayed, and a relatively high reaction force is maintained until a long time has elapsed. In order to reduce the impact on the head, it is necessary to reduce the crush reaction force of the cut-and-raised piece 19 to increase the stroke.

Therefore, the present invention is to reduce the moving distance of the hood to ensure sufficient energy absorption,
It is an object of the present invention to provide a vehicle body upper structure capable of efficiently lowering a C value and reducing head impact.

[0016]

According to the first aspect of the present invention,
An upper body structure of an automobile for absorbing a shock to a hood having a hood outer panel closing an upper surface of an engine room, wherein the shock absorber that absorbs and deforms the shock is disposed in the engine room. wherein provided between the hood outer panel, such that the shock absorber begins to interfere with the impact interference member when said hood is moved to the vehicle body downward a predetermined distance by the impact, upon impact with
From the required energy absorption and HIC value derivation formula,
The ideal waveform of the reaction force and travel distance of
The waveform of the reaction force and the amount of movement of the hood
A gap of a predetermined size is provided between the impact interference body and the hood outer panel so as to approximate each other.

According to a second aspect of the present invention, there is provided an upper structure of an automobile body for absorbing an impact to a hood having a hood outer panel for closing an upper surface of an engine room, wherein the impact interfering body disposed in the engine room and A shock absorber that absorbs and deforms the shock is provided between the hood outer panels, and an inner rib that absorbs and deforms the shock is provided on a lower surface side of the hood outer panel above the shock interference body. A gap of a predetermined size is provided between the shock absorber and the hood outer panel so that the inner rib starts to interfere with the shock absorber when moved downward by a predetermined distance due to an impact. When the hood that has interfered with the body has moved downward by a predetermined distance due to the impact, the impact absorber interferes with the impact interferer. To start, energy required at the time of impact
The reaction force of the hood and the transfer
Find the ideal waveform with the momentum,
The waveform of the reaction force and the amount of movement of the
Thus, a gap of a predetermined size is provided between the impact interference body and the hood outer panel.

According to a third aspect of the present invention, there is provided the vehicle body upper structure according to the first or second aspect, wherein the shock absorber is provided on the hood side.

According to a fourth aspect of the present invention, there is provided the vehicle body upper structure according to the first or second aspect, wherein the shock absorber is provided on the engine room side. .

According to a fifth aspect of the present invention, there is provided the vehicle body upper structure according to the fourth aspect, wherein the shock absorber connects strut towers arranged on both sides of the vehicle width of the engine room. The strut tower is supported.

According to a sixth aspect of the present invention, there is provided the vehicle body upper structure according to the first to fifth aspects, wherein the shock absorber is provided so as to cover an upper portion of the shock interference body. It is assumed that.

According to a seventh aspect of the present invention, there is provided the vehicle body upper structure according to any one of the first to sixth aspects, wherein the shock interference body is an engine, and the shock absorber includes a sound absorbing material. It is a feature.

[0023]

According to the first aspect of the present invention, when the hood receives an impact, the hood outer panel locally deforms, and the initial reaction force of the hood sharply increases to a maximum reaction force. After obtaining the maximum reaction force, the hood outer panel sinks and deforms, and the reaction force decreases due to the inertial force of the hood outer panel.However, when the moving distance of the hood reaches a predetermined distance, the shock absorber interferes with the shock interferer. In addition, the shock absorber is crushed and deformed to generate a secondary reaction force of a desired size, and the reduction of the reaction force is appropriately alleviated. When the movement of the hood further proceeds and the impact energy is completely absorbed, the movement of the hood stops. As a result, the relationship between the reaction force of the hood and the movement distance thereof can be made an ideal state, and the movement distance of the hood can be kept small to ensure sufficient energy absorption, and the HIC value can be reduced efficiently. , The impact on the head can be reduced.

According to the second aspect of the present invention, when the hood receives an impact, the hood outer panel locally deforms, and the initial reaction force of the hood rapidly increases and becomes the maximum reaction force. After obtaining the maximum reaction force, the hood outer panel sinks and deforms,
The reaction force is reduced by the inertia force of the hood outer panel.
At this time, since the gap between the shock absorber and the hood outer panel has a predetermined size, at the initial stage of the sinking deformation, the inner rib starts to interfere with the shock absorber and a reaction force is generated, and the reaction force of the hood is reduced. The ratio can be suppressed to a desired ratio. When the hood outer panel is submerged and deformed, and the moving distance of the hood reaches a predetermined distance, the shock absorber interferes with the shock interferer, and the shock absorber and the inner rib are crushed and deformed, and the secondary of a desired size is deformed. A reaction force is generated, and the reduction of the reaction force is appropriately mitigated. When the movement of the hood further proceeds, the impact interfering body and the inner rib are sufficiently crushed and deformed, the impact energy is completely absorbed, and the movement of the hood stops. As a result, the relationship between the reaction force of the hood and the movement distance thereof can be made an ideal state, and the movement distance of the hood can be kept small to ensure sufficient energy absorption, and the HIC value can be reduced efficiently. , The impact on the head can be reduced.

According to the third aspect of the invention, in addition to the function of the first or second aspect of the present invention, since the shock absorber is provided on the hood side, there is no need to provide a shock absorber in the engine room. The degree of freedom in design can be improved by simplifying the engine room.

According to the fourth aspect of the present invention, in addition to the function of the first or second aspect of the present invention, since the shock absorber is provided on the engine room side, the weight of the hood can be reduced. Opening and closing properties are improved.

According to the fifth aspect of the present invention, in addition to the function of the fourth aspect of the present invention, since the shock absorber connects and supports the strut tower, there is no need to provide a separate component such as a strut tower bar. In addition, the strut tower is prevented from falling down, and the vehicle traveling performance can be stabilized.

According to the sixth aspect of the present invention, in addition to the functions of the first to fifth aspects of the present invention, the shock absorber is provided so as to cover the upper part of the impact interfering body. Can reliably alleviate the impact on the head.

According to the seventh aspect of the present invention, in addition to the effects of the first to sixth aspects of the present invention, the impact interference body is an engine, and the shock absorber has a sound absorbing material. A sound absorbing material can be provided, and noise from the engine can be reduced.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following embodiments according to the present invention are intended to reduce head impact by employing a structure for efficiently reducing the HIC value of a hood of an automobile whose travel distance is restricted. It is.

Specifically, the moving distance of the hood and the HIC
The waveform (ideal waveform) indicating the ideal relationship between the reaction force of the hood and the amount of movement of the hood, which can keep both values small, is calculated based on the amount of energy absorption required at the time of impact and the derivation formula (1).
By calculating in advance based on (2) and performing an impact experiment at a predetermined position of the hood to determine the actual reaction force waveform (basic waveform), the hood structure is such that the basic waveform approaches the ideal waveform. The HIC value is efficiently and reliably reduced with a small moving distance.

Hereinafter, a first embodiment according to the first, third and sixth aspects of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view taken along the line H--H in FIG. 2, showing the main part of the upper structure of the vehicle body according to the first embodiment.
Is a plan view of the hood of FIG. 1, and FIG. 3 is an enlarged plan view of the shock absorber of FIG.

As shown in FIGS. 1 and 2, the hood 31 has a hood outer panel 33. The hood outer panel 33 closes the upper surface of the engine room 35, and an engine 37 as an impact interference body is disposed in a central portion in the engine room 35. An inner panel 39 is adhered to a lower surface 33a of the hood outer panel 33 on the lower side of the vehicle body (the engine room 35 side). The inner panel 39
It has a plurality of inner ribs 41 having a hat-shaped cross section projecting downward from the vehicle body. The inner rib 41 is disposed so as to surround a hood outer panel 33 located above the engine 37, and a shock absorber 43 is provided between the hood outer panel 33 and the engine 37.

Two shock absorbers 43 are provided side by side in the vehicle width direction, and are provided on the hood outer panel 33 side. Each shock absorber 43 is bridged between two support brackets 45, and both ends of each shock absorber 43 are supported by each support bracket 45. As shown in FIG. 3, each support bracket 45 includes an absorber fixing portion 47 on which the shock absorber 43 is mounted and fixed, and two arm portions 49 extending radially with respect to the shock absorber 43 . . As shown in FIG. 1, the tip 49 a of each arm 49 is joined to the inner rib 41, and each arm 49 is provided with an easily deformable portion 51 that allows the shock absorber 43 to move downward in the vehicle body.

Between the shock absorber 43 and the engine 37,
A cover 53 is provided so as to cover the lower surface of the shock absorber 43. When the hood outer panel 33 moves a predetermined distance below the vehicle body between the hood outer panel 33 and the engine 37, the shock absorber 43
A gap having a predetermined size is provided so as to start interference with the gap 7. That is, the hood outer panel 33 and the impact
The sum of the gap D1 between the absorber 43, the gap D2 between the shock absorbing member 43 and the cover 53, and the gap D3 between the cover 53 and the engine 37 is a predetermined value (2 in this embodiment).
(About 0 mm).

FIGS. 11A to 11C show examples of specific shapes of the shock absorbers 43a to 43c used in this embodiment.

The shock absorber 43a shown in FIG.
Is a coil formed so that the plate member 56 has a substantially rectangular cross section. The shock absorber 43b shown in (b) forms a cylindrical body having a substantially rectangular cross section composed of the upper and lower plates 57 and the side plates 59. The upper and lower plates 57 and side plates 59 are provided with holes 61 and 63, and the shock absorber 43c shown in FIG.
5, a vertical wall 67 is provided. Each shock absorber 4
As a material of 3a to 43c, a metal material such as aluminum or a resin material is used.

Next, the operation will be described.

In this embodiment, the hood 3 above the engine 37 is
In the event of an impact on the hood 1, the hood outer panel 33
In order to reduce the impact of the head of the hood 31 even when the interference occurs, the HIC value is reduced at such a position. The hood 31 efficiently reduces the HIC value in an impact test. The structure is such that a waveform similar to an ideal waveform (reaction force (F) of the hood-moving distance due to deformation of the hood) that can be obtained can be obtained.

FIG. 4 is a schematic diagram showing an ideal waveform Cm, and FIGS.
FIG. 7 is a schematic cross-sectional view showing a basic structure in which an impact test was performed, and FIG. 8 is a basic waveform C1, C2, C obtained as a result of the impact test.
3 and an ideal waveform Cm.

The ideal waveform Cm shown in FIG. 4 is an ideal waveform of the reaction force that can suppress both the movement amount of the hood 31 and the HIC value in the basic structure. It is obtained by calculation based on the HIC derivation formula. The internal area A defined by the ideal waveform Cm and the moving distance S on the horizontal axis in the drawing is the absorbed energy, and the internal area A is set so that the required energy absorption amount is obtained. The energy absorption required at the time of impact is obtained by an impact experiment, calculation, or the like.

In the ideal waveform Cm, the initial reaction force suddenly increases at the initial stage of deformation with a small moving distance S, reaches the maximum reaction force F1 at the moving distance S1 (p _{m in the} figure), and becomes the reaction force during the moving distance S2. Although but decreases rapidly to F2, the deformation late after moving distance S2, shoulder secondary reaction force is relaxed the proportion of the reaction force decrease acts (figure q _m) is manifested, further movement distance S3 Then, the reaction force suddenly decreases again, and at the moving distance S0, the impact energy is completely absorbed, and the reaction force reaches almost zero.

As shown in FIG. 5, the basic structure is such that a shock absorber 43 is provided between the engine 37 and the hood outer panel 33. The shock absorber 43 is provided on the upper surface 37 of the engine 37.
a, the hood outer panel 33 and the engine 37
A gap l of a predetermined size is provided between the two. The impact test on the basic structure is performed by applying the impactor 55 to the hood outer panel 33 above the impact absorber 43 and measuring the moving distance and acceleration of the impactor 55. The moving distance and acceleration of the impactor 55 are determined by the moving distance (hood outer panel 3) due to the deformation of the hood shown on the horizontal axis in FIG.
3) and the reaction force of the hood shown on the vertical axis in FIG.

Here, the waveform C1 obtained as a result of the impact experiment on the basic structure as shown in FIG. 5 (FIG. 8 (c))
Conceptually shows a waveform C2 when only the hood outer panel 33 is provided without providing the shock absorber 43 as shown in FIG.
(FIG. 8A) and a waveform C3 (FIG. 8B) obtained when only the shock absorber 43 is provided without the hood outer panel 33 as shown in FIG. 7 can be obtained as a combined waveform. The actual result of the impact test on the base structure is similar to the conceptually determined waveform Cm .

When an impact test was conducted by providing only the hood outer panel 33 as shown in FIG. 6, the waveform C in FIG.
As shown in FIG. 2, in the initial stage of the deformation immediately after the collision, the hood outer panel 33 locally deforms along the outer shape of the impactor 55,
Initial resistance which depends on the tension of the outer hood panel 33 is rapidly increased, the maximum reaction force (approximately F1) is obtained in a state where the moving distance S becomes substantially S1 (figure p _1). After obtaining the maximum reaction force, the hood outer panel 33 starts sinking in a wide range due to the inertial force received from the impactor 55, and the reaction force F suddenly decreases as the moving distance S increases, The force F becomes zero. However, in general, a sufficient amount of energy absorption (area A1) cannot be obtained before reaching this state, and the hood outer panel 33 does not stop but moves further and interferes with the upper surface 37a of the engine 37 to stop. That is, the amount of energy (area A2) absorbed at the time of interference with the engine 37 is the amount of energy that must be absorbed by the shock absorber 43.

When an impact test is performed with only the shock absorber 43 provided as shown in FIG. 7, the shock absorber 55 is delayed by the gap 1 between the hood outer panel 33 and the engine 37 as shown by a waveform C3 in FIG. And the shock absorber 43 interfere with each other, and the shock absorber 43 is crushed and deformed. At this time, the required amount of energy absorption corresponds to the area A2 as described above.

Accordingly, by setting the interval 1 between the hood outer panel 33 and the engine 37 to a predetermined interval, when the waveforms C2 and C3 are matched, the ideal waveform is obtained as shown by a waveform C1 in FIG. A waveform approximate to Cm can be obtained. Note that the waveform C1 and the moving distance S on the horizontal axis are
The area A surrounded by is the sum of the area A1 and the area A2, and the necessary energy absorption is secured.

FIG. 9 shows the HIC value obtained from the result of an impact experiment conducted by changing the size of the gap 1 between the hood outer panel 33 and the engine 37. As shown in FIG.
The C value is higher as the gap 1 is smaller, and decreases as the gap 1 increases. Until the gap 1 becomes about 20 mm, the HIC value decreases relatively sharply.
From about 20 mm, it can be confirmed that the rate of the decrease is moderate. On the other hand, in order to ensure the driver's front view, the hood outer panel 33 is required.
It is desirable to set the gap l between the engine and the engine 37 small. Therefore, it can be understood that the gap l may be set to about 20 mm in order to satisfy both of the requirements of reducing the moving distance of the hood and efficiently reducing the HIC value.

As shown in FIG. 10A, the gap 1 between the hood outer panel 33 and the engine 37 is provided between the shock absorber 43 and the engine 37 by providing the shock absorber 43 on the hood outer panel 33 side. Or (b) of FIG.
As described above, when divided into an upper gap l ₁ and a lower gap l ₂ of the shock absorber 43 is provided a shock absorber 43 in the middle of the hood outer panel 33 and the engine 37 (l ₁ + l ₂ = l)
In this case, substantially the same result as that obtained when the gap 1 is provided between the hood outer panel 33 and the shock absorber 43 is obtained.

As described above, the hood 31 according to the present embodiment
Is the gap between the hood outer panel 33 and the engine 37 (D1
+ D2 + D3) is set to about 20 mm. Therefore, when an impact test is performed on the hood 31, in the initial stage of deformation, the hood outer panel 33 locally deforms along the outer shape of the impactor 55, and the initial deformation occurs. Power increases rapidly and travel distance S is almost
In the state of S1 , a maximum reaction force (approximately F1) is obtained, and after obtaining the maximum reaction force, the hood outer panel 33 is connected to the impactor 55.
With the inertia force received from, the sun begins to sink over a wide range and the reaction force F suddenly decreases. When the moving distance S reaches approximately S2 , the reaction force decreases to approximately F2, and then the hood outer panel 33 and the shock absorbing member When the body 43 interferes to generate a desired secondary reaction force, an appropriate shoulder portion appears, and the shock absorber 43 is sufficiently crushed to completely absorb the shock energy, the reaction force F rapidly decreases again. Is almost zero. Therefore, according to the present embodiment, a waveform similar to the ideal waveform Cm can be obtained, and the HIC value can be effectively reduced with a short moving distance, and the head impact can be reduced.

Since the shock absorber 43 is provided on the side of the hood 31, it is not necessary to provide the shock absorber 43 in the engine room 35, and the degree of freedom in design can be improved by simplifying the engine room 35. it can.

FIGS. 12 to 14 show modified examples of the first embodiment. In this modification, a plate-shaped shock absorber 69 is provided so as to cover the upper surface 37a of the engine 37.
This shock absorber 69 is also supported by the support bracket 45 similarly to the shock absorber 43.

FIGS. 14A to 14C show examples of specific shapes of the shock absorbers 69a to 69c used in this modification.

The shock absorber 69a shown in FIG.
Is formed with a plurality of cutouts 73 in the plate material 71 and cut and raised pieces 75.
In the shock absorbers 69b and 69c shown in FIGS. 7B and 7C, the plate member 71 is notched and a projection 77 having a bottom portion 77b between two inclined portions 77a is cut and raised. Things. The shock absorber 69b shown in (b) and (c)
The shock absorber 69c shown in FIG.
a is substantially the same inclination, whereas the latter has a point where one of the inclined portions 77a is inclined almost vertically, and the bottom 77b is plate-like in the former, while the bottom 77b is almost inclined in the latter. They differ in that they are linear.

As described above, by providing the shock absorber 69 so as to cover the upper surface 37a of the engine 37, a waveform similar to the ideal waveform Cm can be obtained in almost the entire area of the hood outer panel 33 above the engine 37, and a small amount of movement can be obtained. The HIC value can be effectively reduced with the distance, and the head impact can be reliably reduced.

Next, a second embodiment according to the first and fourth to seventh aspects of the present invention will be described with reference to the drawings.

The second embodiment differs from the first embodiment in that a shock absorber 83 is provided on the engine room 35 side.

FIG. 15 is a sectional view showing the upper structure of the vehicle body according to the second embodiment, FIG. 16 is a plan view of FIG.
17 is a sectional view taken along the line JJ in FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 15 to 17, the hood outer panel 33 of the hood 81 and the engine 37 according to the present embodiment are provided.
A shock absorber 83 is disposed in the middle between the two. The size of the gap between the hood outer panel 33 and the engine 37, including the gap D4 between the upper surface 83a of the shock absorber 83 and the hood outer panel 33 and the gap D5 between the lower surface 83b of the shock absorber 83 and the engine 37, is the same as in the first embodiment. Similarly, it is set to be about 20 mm.

Strut towers 89 are provided on both sides of the engine room 35 in the vehicle width.
Is provided so as to protrude from the hood ridge 87 to the inside of the vehicle width. A cylindrical portion 89b protrudes from an upper surface 89a of the strut tower 89, and three bolts / nuts 91 are provided around the cylindrical portion 89b.

The shock absorber 83 is formed by joining an upper plate 83a and a lower plate 83b, and a closed section N is formed between the two plates 83a and 83b. The shock absorber 83 is provided so as to cover the upper part of the engine 37,
4 is connected to the upper surface 89a of the strut tower 89. At both ends 84 of the shock absorber 83, holes 84 fitted externally to the cylindrical portion 89b of the strut tower upper surface 89a.
a is formed, and both ends 84 of the shock absorber 83
It is fitted around the cylindrical portion 89b of the strut tower 89 on both sides of the vehicle width, and is fastened together by the bolts and nuts 91. As a result, the shock absorber 83 is
9 are connected and supported, and the strut tower 8
9 is prevented from falling down.

Further, as shown in FIG. 17, a linear member 85 connected to the engine 37, such as an accelerator wire, is disposed above the engine 37 so that the linear member 85 is not in contact with the linear member 85. In the lower plate 83b of the shock absorber 83, a curved concave portion 86 forming a predetermined gap between the linear members 85 is provided.

According to the second embodiment, the size of the gap (D4 + D5) between the hood outer panel 33 and the engine 37 is set to about 20 mm as in the first embodiment. A waveform similar to the waveform Cm can be obtained, and the HIC value can be effectively reduced with a small moving distance.
Head impact can be reduced.

Further, the shock absorber 83 is attached to the engine room 3
Since it is provided on the fifth side, the weight of the hood 81 can be reduced, and the openability of the hood 81 is improved.

Further, since the shock absorber 83 connects and supports the strut tower 89, the strut tower 89 is prevented from falling down without providing a separate part such as a strut tower bar (not shown), and the strut tower 89 is prevented. The rigidity of the tower 89 is improved, and vehicle traveling performance can be stabilized.

Since the shock absorber 83 is provided so as to cover the upper part of the engine 37, the head impact on almost the entire area of the hood outer panel 33 above the engine 37 can be reliably reduced. This is the same as in the first embodiment.

As shown in FIG. 18, by providing a sound absorbing material 91 such as glass wool in the closed cross section N of the shock absorber 83, the upper part of the engine 37 can be covered by the sound absorbing material 91. The noise from the 37 can be reduced. In this case, by forming holes 93 in the upper plate 83a and the lower plate 83b of the shock absorber 83, the crush reaction force and energy absorption of the shock absorber 83 can be accurately adjusted, and the sound absorbing material 91 is provided. Can further improve the soundproofing effect.

Next, a third embodiment according to the second and fourth to seventh aspects of the present invention will be described with reference to the drawings.

The third embodiment differs from the first embodiment in that an inner rib 41 is provided between the shock absorber 83 and the hood outer panel 33.

FIG. 19 is a sectional view showing the upper structure of a vehicle body according to the third embodiment, and FIG. 20 is a sectional view taken along the line KK of FIG. The same parts as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 19 and 20, the hood 95 according to this embodiment has a hood inner panel 39 provided with a hood inner rib 41 provided on the hood outer panel 33 above the engine 37 by bonding. Absorber 8
3, a gap D6 between the upper surface 83a and the hood inner rib 41;
The gap D7 between the lower surface 83b of the shock absorber 83 and the engine 37
The size of the gap between the hood outer panel 33 and the engine 37 in which
It is set to be about mm. Also, with respect to the gap D6 between the upper surface 83a of the shock absorber 83 and the inner rib 41 as a gap between the shock absorber 83 and the hood outer panel 33, the hood outer panel 33 moves a predetermined distance below the vehicle body, and When the reaction force of 95 reaches the maximum reaction force, the inner rib 41
The predetermined size is set so as to interfere with As in the second embodiment, the shock absorber 83 is provided so as to cover the upper part of the engine 37, and both ends 84 are connected to the upper surface 89a of the strut tower 89. This allows
The shock absorber 83 is connected to and supports the strut tower 89, and the strut tower 89 is prevented from falling down. A linear member 85 is disposed above the engine 37, and a curved concave portion 8 that forms a predetermined gap between the linear members 85 is provided in a lower plate 83b of the shock absorber 83.
6 are provided.

Next, the operation will be described. The hood 19 according to the present embodiment has a structure capable of obtaining a waveform similar to an ideal waveform in an impact test, as in the first embodiment.

FIG. 21 shows a deformation state of the basic structure at the time of an impact test, and FIG. 22 shows a deformation state of the hood 95 according to this embodiment at the time of an impact test. FIG.
3 shows a basic waveform C4 and an ideal waveform Cm obtained as a result of an impact test on the basic structure. Note that the waveform obtained as a result of the impact experiment on the hood 95 according to the present embodiment is not illustrated because it is similar to the ideal waveform Cm.

As shown in FIG. 21, the basic structure is the shock absorber 8
3 is the same as the configuration of the present embodiment except that the third embodiment is not provided.

The deformation state of the impact test on the basic structure,
The relationship between the movement distance S of the hood and the reaction force F in each state is
A description will be given based on FIG. 21 and FIG.

As shown in FIG. 21 (a), the hood outer panel 33 in the initial stop state [initial velocity v ₀ = 0 of the inner rib 41] has an impactor 55 [initial velocity V ₀ > of the impactor 55].
0], a force is applied to the hood outer panel 33 from the impactor 55 as shown in FIG. During this time, the speed V ₁ of the impactor 55 is greater than the speed v ₁ of In'naribu 41 [V _1>
v ₁ ], the hood outer panel 33 locally deforms along the outer shape of the impactor 55, and as shown in a range I in FIG. 23, the initial reaction force rises to a maximum reaction force (approximately F1). (figure p ₄₎ is, then, the hood outer panel 33 starts sinking over a wide range by an inertial force received from the impactor 55, the reaction force F begins to rapidly decrease.

As shown in FIG. 21C, when the hood outer panel 33 is sufficiently accelerated and the speed V _{2 of the} impactor 55 becomes lower than the speed v _{2 of the} inner rib 41, [V ₂ <
v ₂ ], as shown in a range II in FIG. 23, the reaction force F of the hood becomes zero.

[0079] movement of the hood is advanced, In'naribu without becoming In'naribu 41 as (d) in FIG. 21 starts the interference with the engine 37, the speed V ₃ of the impactor 55 is zero and 4
Only one of the speed v ₃ becomes zero _{[V 3> 0, v 3} = 0].
That is, the inner rib 41 absorbs the impact energy and undergoes crushing deformation, and a high reaction force F is generated as shown in a range III in FIG. 23 (in the figure).

When the inner rib 41 is sufficiently deformed and the impact energy is completely absorbed, the movement of the hood stops as shown in FIG. 21 (e), and as shown in a position IV in FIG. The reaction force F becomes zero.

[0081] In this way basic waveform C4, until a maximum reaction force initial resistance by the hood outer panel 33 to deform the initial stage with rapid increase (figure p _4), approximates the ideal waveform Cm.

However, in the basic waveform C4, the rate of reduction of the reaction force F after reaching the maximum reaction force is extremely large as compared with the ideal waveform Cm, and even after the reaction force F becomes F2 in the later stage of deformation. Further, the reaction force F decreases, and thereafter, the reaction force F becomes zero without being relaxed, and the shoulder portion (q _{m in the} figure) hardly appears.
And greatly different. That is, it is not possible to secure a sufficient energy absorption amount with the absorbed energy (area A3 in FIG. 23) before the inner rib 41 interferes with the engine 37, and a large absorbed energy (area A4 in FIG. 23) when the inner rib 41 interferes with the engine 37. Therefore, the reaction force F increases after a long time from the start of the impact (r _{4 in the} figure), which has an adverse effect on the head impact.

On the other hand, the hood 95 according to the present embodiment
The hood outer panel 33 in the initial stop state [initial velocity v ₀ = 0 of the inner rib 41] as shown in FIG.
When the impactor 55 interferes with the initial velocity V ₀ > 0 of the impactor 55, a force is applied to the hood outer panel 33 from the impactor 55 as shown in (b), and the hood outer panel 33 is accelerated. During this time, the speed V ₁ of the impactor 55 is greater than the speed v _{1 of the} inner rib 41 [V ₁ > v ₁ ], and the hood outer panel 33 locally deforms along the outer shape of the impactor 55, and the basic structure Similarly, the initial reaction force in the range Im in FIG. 23 rises and becomes the maximum reaction force (substantially F1).

When the hood generates the maximum reaction force, the hood outer panel 33 starts to sink over a wide range due to the inertial force received from the impactor 55. At this time, as shown in FIG. 23, the reaction between the inner rib 41 and the shock absorber 83 generates a reaction force as shown in FIG. 23 (c), and the reaction force F is prevented from sharply decreasing compared to the basic structure. The reaction force F is reduced substantially equal to the ideal waveform Cm in the range IIm.

[0085] When the movement distance S of the hood reaches a predetermined distance, the shock absorber 83 starts interference with the engine 37, In'naribu 41 via the shock absorber 83 is the engine as (d) in FIG. 22 Interferes with 37. At this time, only the speed v ₃ of In'naribu 41 without becoming velocity V ₃ of the impactor 55 is zero and is zero _{[V 3> 0, v 3} = 0]. That is, the inner rib 41 and the shock absorber 83 absorb the shock energy to cause crushing deformation, a desired secondary reaction force is generated in the hood, and the rate of reduction of the reaction force F as a whole is alleviated.
Substantially the same shoulder portion and the ideal waveform Cm in the range IIIm in 3 (in the figure q _m) is obtained.

When the inner rib 41 and the shock absorber 83 are sufficiently deformed to completely absorb the shock energy, FIG.
23 (e), the movement of the hood stops, and the reaction force F becomes zero as shown by the ideal waveform Cm at the position IV in FIG.

As described above, the hood 95 according to this embodiment is
When an impact experiment is performed on the hood, the hood outer panel 33 locally deforms along the outer shape of the impactor 55 in the initial stage of deformation, the initial reaction force increases rapidly, and the maximum reaction occurs when the moving distance S becomes approximately S1. After the force (approximately F1) is obtained and the maximum reaction force is obtained, the hood outer panel 33 starts sinking over a wide range due to the inertial force received from the impactor 55,
When the inner rib 41 interferes with the engine 37, the reaction force F decreases at an accurate rate, and when the moving distance S reaches approximately S2 , the reaction force decreases to approximately F2. When the inner rib 41 and the shock absorber 83 are sufficiently crushed, the reaction force F decreases sharply again, and the desired secondary reaction force is generated. And the movement of the hood stops. That is, according to the present embodiment, a waveform similar to the ideal waveform Cm can be obtained as in the first embodiment.

As described above, according to the third embodiment, the gap between the hood outer panel 33 and the engine 37 (D6 + D7)
Is set to about 20 mm as in the first embodiment,
And the gap D between the hood outer panel 33 and the shock absorber 83
6 is set to a predetermined value, the rate of reduction of the reaction force after the maximum reaction force is too large, and the secondary reaction force is small and almost no shoulder (qm in FIG. 23) appears. With respect to a structure having no reaction force, the reduction of the reaction force after the maximum reaction force can be set at an appropriate ratio, and the secondary reaction force can be appropriately increased. As a result, a waveform approximating the ideal waveform Cm at the time of impact is obtained, and the HIC value can be effectively reduced with a short moving distance, and head impact can be reduced.

Further, similarly to the second embodiment, the shock absorber 8
3 is provided on the engine room 35 side, so that the hood 8
The opening and closing of the hood 81 is improved by reducing the weight of the hood 1, and the shock absorber 83 is connected to and supports the strut tower 89, so that the running performance of the vehicle can be stabilized and the upper part of the engine 37 is covered. Since the shock absorber 83 is provided as described above, it is possible to surely reduce the head impact in almost the entire area of the hood outer panel 33 above the engine 37.

Further, by providing a sound absorbing material in the closed cross section of the shock absorber 83, the noise from the engine 37 can be reduced as in the second embodiment.

[0091]

As described above, according to the first aspect of the present invention, when the moving distance of the hood reaches a predetermined distance, the shock absorber interferes with the shock interferer, and the shock absorber is crushed and deformed. As a result, a secondary reaction force of a desired magnitude is generated, and the reduction of the reaction force is appropriately mitigated. Therefore, the relationship between the reaction force of the hood and the moving distance thereof can be made an ideal state, and the moving distance of the hood Can be suppressed to ensure sufficient energy absorption, and the head impact can be reduced.

According to the second aspect of the present invention, when the moving distance of the hood reaches a predetermined distance, the inner rib interferes with the impact interference body, and the hood reaction force decreases at the initial stage of the hood outer panel sinking deformation after the maximum reaction force. Can be suppressed to a desired ratio, and when the moving distance of the hood reaches a predetermined distance, the shock absorber interferes with the shock interferer, and the shock absorber is crushed and deformed, and a secondary of a desired size is formed. Since the reaction force is generated and the reduction of the reaction force is appropriately mitigated, the relationship between the reaction force of the hood and the moving distance can be set to an ideal state. And the impact on the head can be reduced.

According to the third aspect of the present invention, in addition to the effects of the first or second aspect of the present invention, the degree of freedom in design can be improved by simplifying the engine room.

According to the fourth aspect of the present invention, in addition to the effects of the first or second aspect of the present invention, the hood can be opened and closed easily by reducing the weight of the hood.

According to the fifth aspect of the present invention, in addition to the operation of the fourth aspect of the present invention, it is possible to stabilize the vehicle traveling without providing a separate component such as a strut tower bar.

According to the invention set forth in claim 6, claims 1 to 1 are provided.
In addition to the effect of the fifth aspect of the invention, it is possible to surely reduce the head impact in almost the entire area above the impact interfering body.

According to the invention of claim 7, claims 1 to 1 are provided.
In addition to the effect of the invention described in claim 6, noise from the engine can be reduced by the sound absorbing material.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a main part of a vehicle body upper structure according to a first embodiment.

FIG. 2 is a plan view of the hood of FIG.

FIG. 3 is an enlarged plan view of the impact interference body of FIG. 2;

FIG. 4 is a schematic diagram showing an ideal waveform Cm.

FIG. 5 is a sectional view showing a basic structure of the first embodiment.

FIG. 6 is a sectional view showing a basic structure of the first embodiment.

FIG. 7 is a sectional view showing a basic structure of the first embodiment.

8A and 8B are schematic diagrams of waveforms showing a relationship between a reaction force F of the hood and a moving distance S, wherein FIG. 8A shows a waveform C2 corresponding to the basic structure of FIG. 6, and FIG. FIG. 6C shows a waveform C1 corresponding to the basic structure shown in FIG.
And an ideal waveform Cm.

FIG. 9 shows a gap 1 between the engine and the hood outer panel and HI.
It is the schematic which shows the relationship with a C value.

FIG. 10 is a sectional view showing another basic structure.

FIG. 11 is a perspective view showing a shock absorber.

FIG. 12 is a plan view of a hood showing a modification of the first embodiment.

FIG. 13 is an enlarged plan view of the impact interference body of FIG.

FIG. 14 is a perspective view showing a shock absorber.

FIG. 15 is a side sectional view showing an upper structure of a vehicle body according to a second embodiment.

FIG. 16 is a plan view of the hood of FIG.

FIG. 17 is a sectional view taken along the line JJ of FIG. 15;

FIG. 18 is a perspective view showing a shock absorber provided with a sound absorbing material.

FIG. 19 is a side sectional view showing an upper body structure of an automobile according to a third embodiment.

20 is a sectional view taken along the line KK of FIG.

FIG. 21 is a cross-sectional view showing a deformed state at the time of an impact test on the basic structure.

FIG. 22 is a cross-sectional view illustrating a deformed state of the hood according to the third example during an impact test.

FIG. 23 is a schematic diagram showing a basic waveform C4 and an ideal waveform Cm of the third embodiment.

FIG. 24 is a perspective view showing an automobile having a conventional body upper structure.

FIG. 25 is an enlarged view of a main part of FIG. 24;

26 is a sectional view taken along line VV of FIG. 25.

FIG. 27 is a diagram showing a WSTC.

[Explanation of symbols]

31 Hood 33 Hood outer panel 33a Lower surface of hood outer panel 35 Engine room 37 Engine (shock absorber) 41 Inner rib 43 Shock absorber 43a Shock absorber 43b Shock absorber 43c Shock absorber 69 Shock absorber 69a Shock absorber 69b Shock absorber 69c Shock absorber 81 Hood 83 Shock absorber 89 Strut tower N Closed cross section D1 + D2 + D3 Gap between shock interferer and hood outer panel D4 + D5 Gap between shock interferer and hood outer panel D6 + D7 Gap between shock interferer and hood outer panel D6 Shock absorber Clearance between body and hood outer panel

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B62D 25/10

Claims (7)

(57) [Claims] 1. An upper body structure of an automobile for absorbing a shock to a hood having a hood outer panel closing an upper surface of an engine room, wherein a shock absorber that absorbs and deforms the shock is disposed in the engine room. The shock absorber is provided between the shock absorber and the hood outer panel, and the shock absorber is required to start interference with the shock interferer when the hood moves downward by a predetermined distance due to the shock. Energy absorption and
From the HIC value derivation formula, the ideal of the reaction force of the hood and the amount of movement
Hood reaction force and movement obtained by shock experiment
An upper body structure of an automobile, wherein a gap having a predetermined size is provided between the impact interference body and the hood outer panel so that a waveform of the amount approximates the ideal waveform . 2. An upper body structure of an automobile for absorbing an impact to a hood provided with a hood outer panel for closing an upper surface of an engine room, wherein: a shock absorber interposed in the engine room and the hood outer panel; A shock absorber that absorbs and deforms the shock; an inner rib that absorbs and deforms the shock is provided on a lower surface side of the hood outer panel above the shock interfering body; A gap of a predetermined size is provided between the shock absorber and the hood outer panel so that the inner rib starts to interfere with the shock absorber when moved downward, and a hood that interferes with the shock absorber is provided. as the shock absorbing member when moved to the vehicle body downward a predetermined distance by the impact starts interfering with the impact interferents, opposition Sometimes need
Of the hood from the high energy absorption and the HIC value derivation formula
Find the ideal waveform of force and travel and obtain it in an impact experiment.
The waveform of the reaction force and the amount of movement of the hood approximates the ideal waveform
A gap having a predetermined size is provided between the impact interfering body and the hood outer panel so as to perform the above operation. 3. The vehicle body upper structure according to claim 1, wherein the shock absorber is provided on the hood side. 4. The vehicle body upper structure according to claim 1, wherein the shock absorber is provided on the engine room side. 5. The upper structure of a vehicle body according to claim 4, wherein the shock absorber connects the strut towers arranged on both sides of the vehicle width of the engine room to support the strut towers. An upper body structure of an automobile characterized by the following. 6. The upper part of an automobile body according to claim 1, wherein said shock absorber is provided so as to cover an upper part of said impact interference body. Construction. 7. The vehicle body upper structure according to claim 1, wherein the shock interference body is an engine, and the shock absorber includes a sound absorbing material. Superstructure.