JP2002137706A - Impact energy absorbing structure of impact absorbing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve impact energy absorbing performance by adopting a structure in which a plurality of spaces are bored extending along a direction of collision of an occupant's head compared with an impact absorbing member having no space with the same thickness. SOLUTION: The plurality of spaces 38 opening on an outer surface 34 facing a pillar garnish 10 and extending in the same direction or substantially in the same direction as the direction of collision of the occupant's head 18 are bored in position at specified intervals in a body 32. When the pillar garnish 10 is deformed due to the collision with the occupant's head 18, a connecting part 40 positioned between the spaces 38 experiences collapse deformation, so that the impact energy absorbing performance improves compared with the impact absorbing member having no space 38 with the same thickness. The spaces 38 may be in the form of through holes, also opening on an outer surface 36 facing a pillar 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock energy absorbing structure for a shock absorbing member, and more particularly, to a shock absorbing member having a required thickness made of polyurethane foam or the like and installed in a passenger compartment of a vehicle. The present invention relates to an impact energy absorbing structure interposed between a vehicle interior member and a vehicle body component so as to reduce the impact of an occupant's head colliding with the vehicle interior member.

[0002]

2. Description of the Related Art In automobiles and the like designed in recent years, the safety of collision is improved for the purpose of protecting occupants. For example, as shown in FIGS. 10 and 11, a housing space 1 defined by a pillar garnish 10 as a vehicle interior member and a pillar 12 as a vehicle body component member installed in the passenger compartment.
4, an impact absorbing member 16 made of polyurethane foam or the like is interposed between the pillar garnish 10 and the head 18 of the occupant thrown forward in reaction to the frontal collision accident.
When a collision occurs, measures are being taken to alleviate the impact by crushing the impact absorbing member 16. Although not shown, a shock absorbing member as described above is interposed in a housing space defined by a roof side garnish as a vehicle interior member and a roof panel as a vehicle body component, so that a side reaction can be caused by a side collision. Crew's head 18
In the event of a collision with the roof side garnish, measures are being taken to reduce the impact by crushing the impact absorbing member.

As a test for measuring the impact energy absorbing performance of the impact absorbing member 16, for example, a "head impact test" can be mentioned. In this head impact test, as shown in FIG.
The head form impactor 2 is placed on a sample material 26 of a specified size set on the set table 22.
0 head form (head model) 24 at 24 km / h (1
By making a free flight at 5 miles / h, HIC (Head InjuryCriter) is used based on the data obtained at this time.
ia: head injury) value is calculated. This HIC
The value is a numerical value obtained by substituting the time history data of the acceleration generated in the head form 24 at the time of the collision into a required evaluation formula, and it is evaluated that the smaller the numerical value, the more the head injury can be reduced. Generally, it is considered that “1000” is desirably smaller than the evaluation reference value.

[0004]

When the shock absorbing members 16 made of a rigid polyurethane foam are made of the same material, the shock absorbing members 16 are generally made to have an impact in proportion to the thickness in the direction in which the head 18 collides. Since the energy absorption performance is improved, the thickness may be set large to reduce the HIC value. However, the accommodation space 14 defined by the pillars 12 and the pillar garnish 10 and the accommodation space defined by the roof panel and the roof side garnish cannot be unlimitedly large. Enlarging the accommodating space 14 has a problem that the respective garnishes protrude into the occupant compartment, causing a forward view and a narrower occupant compartment. That is, since the impact absorbing member 16 must be accommodated in the limited accommodation space 14, the setting of the thickness of the impact absorbing member 16 is restricted, and the impact absorbing member actually used in practice is In many cases, it is not possible to secure a thickness sufficient to satisfy the impact energy absorbing performance.

However, if the thickness of the shock absorbing member 16 is reduced, the bottom of the shock absorbing member 16 is quickly settled and the impact energy absorbing performance is degraded, so that the urethane foam itself is hardened. . However, when the shock absorbing member 16 is hardened, it is difficult to crush and deform, so that the disadvantage of bottoming can be avoided. However, since the crush deformation is not properly performed, the impact energy absorbing performance is rather deteriorated. In general, there still remains a problem in reducing the HIC value below the evaluation reference value.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems suitably, and has a structure in which a plurality of spaces extending in the collision direction of the occupant head are provided at required positions. Shock absorption in which the portion corresponding to the collision portion of the occupant head is crushed and deformed, so that the shock energy absorbing performance can be improved more than the shock absorbing member of the same thickness having no space portion. An object is to provide an impact energy absorbing structure for a member.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and achieve the intended object, the present invention comprises a shock absorbing member made of polyurethane foam or the like and having a required thickness.
An impact energy absorbing structure interposed between a vehicle interior member installed in a passenger compartment of a vehicle and a vehicle body constituent member so as to reduce an impact of an occupant head colliding with the vehicle interior member. A plurality of spaces are provided at predetermined positions of the main body at predetermined intervals, the spaces being opened on the outer surface of the member facing the vehicle interior member and extending in the same or substantially the same direction as the collision direction of the occupant's head. When the vehicle interior member is deformed due to the collision of the occupant head, the continuous portion located between the space portions is crushed and deformed, so that the same thickness without the space portion is provided. It is characterized in that it is configured to be able to improve the impact energy absorbing performance more than the impact absorbing member of (1).

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a shock energy absorbing structure of a shock absorbing member according to the present invention will be described below with reference to the accompanying drawings by way of preferred embodiments. FIG. 1 is a perspective view schematically showing a shock absorbing member according to the present embodiment, and this shock absorbing member 30 is used as a vehicle interior member installed in a passenger compartment of a vehicle, for example, as shown in FIG. Pillar garnish 10 and pillar 1 as a vehicle body component
2 to reduce the impact of the occupant's head 18 that is thrown forward and collides with the pillar garnish 10 in the event of a vehicle collision.

Here, in the shock absorbing member 30 of the embodiment, as a shock energy absorbing structure for reducing the shock of the occupant's head 18, a first outer surface 34 of the main body 32 which faces the pillar garnish 10 is used. And a plurality of through-hole-shaped spaces 38 respectively opened at the second outer surface 36 facing the pillar 12 at predetermined positions of the main body 32 at predetermined intervals. It is assumed that a continuous portion 40 is provided. That is, each space portion 38
When the shock absorbing member 30 is interposed in the accommodation space 14, it extends from the side of the pillar garnish 10 to the side of the pillar 12, and the occupant head 18 with respect to the pillar garnish 10 It extends in the same or substantially the same direction as the collision direction.

The main body 32 includes, for example, a polyol component,
A mixture of an isocyanate component, a foaming agent, a catalyst, a foam stabilizer, and other auxiliaries is made of a rigid urethane foam formed by foaming using a foaming mold, and foamed by a foaming mold (not shown). By adjusting the mixing ratio of each component, its hardness can be adjusted. Each of the space portions 38 in the main body 32 is formed by a method of simultaneous molding at the time of foam molding of the main body 32, a method of drilling with a drill or a cutter in a later step after the foam molding of the main body 32, or the like. . Each space 3
8 does not need to be a through hole opened on both surfaces of the first and second outer surfaces 34 and 36, and at least the first outer surface 3
4 and may extend in the same or substantially the same direction as the collision direction of the occupant head 18.

As described above, the plurality of space portions 3 are provided in the main body 32.
The shock absorbing member 30 of the embodiment having an impact energy absorbing structure in which a plurality of continuous portions 40 are provided between the respective spaces 38 by forming the shock absorbing members 8 at required intervals, When the pillar garnish 10 is protruded and deformed toward the accommodation space 14 due to the collision of the vehicle, the continuous portion 40 corresponding to the deformed portion is crushed and deformed, and the impact of the occupant head 18 is reduced. Energy is efficiently absorbed. As a result, the shock energy absorbing performance is more suitably improved than the conventional shock absorbing member 16 having the same thickness without the space portion 38 (FIGS. 10 and 11).

Next, the impact energy absorbing performance of the impact absorbing member 30 of the embodiment configured as described above will be described.
A description will be given based on the results of a head impact test performed using a plurality of sample materials shown in FIGS. In this test, as shown in Table 1, the presence or absence of the space 38 and the space 3
First to fourth sample materials 4 different in size and number of 8
2, 44, 46 and 48 are prepared, and the respective sample materials 42 and 42 are prepared using the head form impactor 20 shown in FIG.
A head impact test was performed on 44, 46 and 48.

[0013]

As shown in FIGS. 3 and 4, the first sample material 42 is a sample assuming the shock absorbing member 30 of the embodiment, and has L = 80 mm, W = 100 mm, and H = 2.
A main body 32 having an outer size of 0 mm is formed. A through-hole-shaped space 38 having a diameter D = 12 mm, which is opened on both surfaces of a first outer surface 34 and a second outer surface 36 of the main body 32, has a vertical interval A.
= 30 mm, lateral spacing B = 30 mm, and 3 × 2 = 6 pieces. As shown in FIG. 5, the second sample material 44 has L = 80 mm, W = 100 mm, and H = 20 m.
m of a main body 32 having an outer size of
A through hole-shaped space 38 having a diameter D = 12 mm opened on both surfaces of the outer surface 34 and the second outer surface 36 of
In this example, 5 × 4 = 20 pieces were formed with 0 mm and the horizontal interval B = 20 mm. On the other hand, as shown in FIG. 6, the third sample material 46 has L = 80 mm, W = 100 mm, and H = 20 m.
m of a main body 32 having an outer size of
A space portion 38 having a through-hole shape with a diameter D = 8 mm, which is opened on both surfaces of the outer surface 34 and the second outer surface 36, has a vertical interval A = 20.
mm, the horizontal interval B = 20 mm, and 5 × 4 = 20 pieces were formed. As shown in FIG. 7, the fourth sample material 48 is a sample assuming the conventional shock absorbing member 16 without the space 38, and the first to third sample materials 42, 44, 46 Same as L = 80mm, W = 100m
The main body 32 has an outer size of m and H = 20 mm.

Then, each of the first to fourth sample materials 4
In 2,44,46,48, the urethane stress S was 0.73 MPa, 0.79 MPa, 0.88 MPa, 1.3 to confirm the change in the HIC value due to the difference in hardness of the main body 32.
Four types of different hardness of 7 MPa were prepared. The urethane stress S is L = 50 mm, W = 50 mm, H =
In a sample material having an outer size of 50 mm, the stress generated when compressing the thickness from 50 to 10 mm is 50%.
% Value. That is, the larger the value of the urethane stress S, the harder the material.

Table 2 shows the first to fourth types of different hardness.
Regarding the fourth respective sample materials 42, 44, 46, 48,
4 is a data table of HIC values obtained based on a head impact test by the head form impactor 20.
FIG. 8 is a graph created based on this data table.

[0017]

First, the HIC value of the fourth sample material 48 assuming the conventional shock absorbing member 16 is a minimum of 1,072 when the urethane stress S is 0.79 MPa, and is 1,122 at a softer 0.73 MPa. At 0.88 MPa and 1.37 MPa, which are harder than this, respectively 1.1
69 and 1,422. Urethane stress S is 0.7MP
The reason why the HIC value increases in the relatively soft region A (FIG. 8) that is smaller than or equal to a is that the main body 32 is crushed and deformed to the bottomed state and the head form 24 comes into contact with the set table 22. This indicates that energy cannot be completely absorbed. When the urethane stress S is 0.79 MPa, the HIC
The value is small because the main body 32 was crushed and deformed without being in a bottomed state.
m indicates that the HIC value cannot be less than 1000 even if the crush deformation is optimal. On the other hand, the reason why the HIC value becomes large in the relatively hard region C (FIG. 8) in which the urethane stress S is 0.9 MPa or more is because proper crushing deformation does not occur in the main body 32, and the impact energy is too hard to properly This indicates that it cannot be completely absorbed. For this reason, in the fourth sample material 48 having no space portion 38, the urethane stress S is equal to 0.
Even if the impact energy absorption performance is best at a hardness of about 8 MPa, it is impossible to reduce the HIC value to 1000 or less.

Next, the HIC value of the first sample material 42 assuming the shock absorbing member 30 of the embodiment is a minimum 964 when the urethane stress S is 0.79 MPa, and is 1,102 at a softer 0.73 MPa. At 0.88 MPa and 1.37 MPa, which are harder than this, 1.0 and 1.0 MPa respectively.
74, 1,259. Here, the reason why the HIC value is large in the region A where the urethane stress S is 0.7 MPa or less is that as shown in FIG.
This is because the head form 24 came into contact with the set base 22 with the main body 32 in the bottomed state as in the case of 8, and this hardness indicates that the impact energy cannot be completely absorbed.

However, the urethane stress S is 0.79 MPa.
Although the thickness H is the same as the fourth sample material 48, that is, 20 mm, the HIC value is decreased from 1,072 by 108 to 964 of 1,000 or less. This is because, as described above, the space portions 38 are formed in the main body 32 at required intervals, and as shown in FIG. This is because the head foam 24 was appropriately crushed and deformed by the collision and the impact energy was appropriately absorbed. That is, a through-hole-shaped space portion 38 having a diameter D = 12 mm opened on both surfaces of the first outer surface 34 and the second outer surface 36 of the main body 32 has a vertical interval A = 30 mm, a horizontal interval B = 30 mm, and 3 × 2 = 6
Due to the formation, the respective connecting portions 40 located between the respective space portions 38 are appropriately crushed and deformed by the collision of the headform 24, and the impact energy can be appropriately absorbed at the time of the crushing deformation. Means that.

Note that L = 80 mm, W = 100 mm, H
= 25 mm (5 m thicker than the fourth sample material 48)
m), the urethane stress S
Has a HIC value of about 950 at around 0.79 MPa. Therefore, in the first sample material 42, when the urethane stress S is about 0.8 MPa, the impact energy absorption performance is the best, and the HIC value at this time is the sample material having no space 38 having a thickness H = 25 mm. It was confirmed that it became almost equivalent.

On the other hand, the reason why the HIC value increases in the relatively hard region C is that even if each of the space portions 38 is formed as described above, as shown in FIG. This indicates that no crushing deformation occurs, so that even if the space 38 is formed, it is too hard to properly absorb impact energy. However, since the HIC value in the region C is always appropriately smaller than the HIC value of the fourth sample material 48, it can be confirmed that the impact energy absorbing performance is improved by forming the space portion 38.

The HIC value of the second sample material 44 is
When the urethane stress S was 0.79 MPa, it was 1,127, and when it was higher than 0.88 MPa and 1.37 MPa, it was 1,268,1123, respectively. The HIC value did not become 1000 or less regardless of the hardness of the polyurethane foam. That is, in the second sample material 44, since the number of the space portions 38 formed is three times or more as compared with the first sample material 42, the strength of each of the continuous portions 40 is significantly reduced, and the area B
However, it is considered that the HIC value increased due to the bottom of the main body 32. In the region C, as the urethane stress S increases, the HIC value decreases. When the urethane stress S becomes about 1.16 MPa or more, the HIC value is lower than that of the fourth sample material 48. Then, each connecting portion 40 can be appropriately crushed and deformed without bottoming. Therefore, for example, if the urethane stress S is 1.6 MPa or more, it can be said that the HIC value may be about 1000.

The HIC value of the third sample material 46 is
The urethane stress S is 1,204 at 0.79 MPa, 1,208 at 0.73 MPa, and 1,2 at 0.88 MPa and 1.37 MPa, respectively.
28, 1209, and the HIC value was always about 1200 irrespective of the hardness of the polyurethane foam.

From the above test results, 80 (L) × 100
In the shock absorbing member 30 having the outer size of (W) × 20 (H),
The first sample material 42 having a urethane stress S of about 0.79 MPa (the first outer surface 34 and the second outer surface 36 of the main body 32).
A space portion 38 in the form of a through-hole having a diameter D = 12 mm and opening on both sides of the surface is formed with a vertical interval A = 30 mm and a horizontal interval B = 30 mm
3 × 2 = 6), the thickness H = 20 m
It was confirmed that even with m, the HIC value could be made 1000 or less. That is, the shock absorbing member 30 of the embodiment in which a plurality of spaces 38 extending in the same or substantially the same direction as the collision direction of the human head 18 with respect to the main body 32 is appropriately provided.
The shock energy absorbing performance is improved as compared with the shock absorbing member 16 having the same thickness without the space 38.

In the above-mentioned test, in the first sample material 42, when the urethane stress S of the polyurethane foam forming the main body 32 was set to about 0.7 to 0.9 MPa, the improvement of the impact energy absorbing performance was confirmed. This is mainly the result of assuming sedan-based vehicles. That is, for example, in a one-box car or a wagon-based car, the position and angle of the pillar 12 are different from those of the sedan-based car, whereby the collision direction and the collision strength of the occupant head 18 against the shock absorbing member 30 are also reduced. Subtly different. Therefore, considering that the shock absorbing member 30 of the embodiment is applied to various types of automobiles, the urethane stress S of the polyurethane foam forming the main body 32 is 0.4 to 0.4.
Within the range of 0.9 MPa, an improvement in impact energy absorption performance can be expected.

However, it is important to appropriately set the size, number and position of the space 38 depending on the outer size, outer shape, and hardness of the main body 32 of the shock absorbing member 30.

Further, in the embodiment, the case where the sectional shape of the space 38 is circular is illustrated, but the sectional shape of the space 38 is not limited to this, and may be, for example, an ellipse or a polygon.

Further, in the embodiment, the case where the space portion 38 having the same shape and the same size is provided in the main body 32 is exemplified.
The space portions 38 having different shapes may be provided at appropriate intervals, or the space portions 38 having different sizes may be provided at appropriate intervals. Further, the vertical interval A and the horizontal interval B, which are the arrangement intervals of each space portion 38, may be different for each part of the main body 32.

[0030]

As described above, according to the impact energy absorbing structure of the impact absorbing member according to the present invention, when it is interposed between the vehicle interior member and the vehicle body component, the impact direction of the human head is the same. Alternatively, by providing a plurality of spaces extending substantially in the same direction at appropriate intervals, there is an advantage that the shock energy absorbing performance can be improved as compared with a shock absorbing member having the same thickness without the spaces. The space may be open at least on the outer surface of the vehicle interior member,
Further, it may have a through-hole shape that is opened also on the outer surface on the side of the vehicle body component. The urethane stress of the polyurethane foam forming the shock absorbing member is 0.4 to 0.9 MPa.
It is desirable to be about.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an example of a shock absorbing member according to a preferred embodiment of the present invention.

FIG. 2 shows a shock absorbing member shown in FIG. 1 interposed in a housing space defined between a pillar garnish as a vehicle interior member and a pillar as a vehicle body component, and a passenger head that collides with the pillar garnish. It is sectional drawing shown in the implementation state which aimed at the impact relaxation.

FIG. 3A is a plan view of a first sample material, and FIG.
FIG. 3A is a sectional view taken along line III-III of FIG.

FIG. 4 is a schematic perspective view of a first sample material.

FIG. 5 is a plan view of a second sample material.

FIG. 6 is a plan view of a third sample material.

FIG. 7 is a perspective view of a fourth sample material.

FIG. 8 is a graph showing calculation results of respective HIC values in first to fourth sample materials of four types having different hardnesses.

FIG. 9 (a) shows a case where the main body is too soft and bottomed out when the head form collides, and FIG. 9 (b) shows a case where the main body has an appropriate hardness, so (C) shows a case where the main body is too hard and does not appropriately collapse and deform when the headform collides.

FIG. 10 is a perspective view showing an example of a conventional shock absorbing member, partially cut away.

FIG. 11 shows the shock absorbing member shown in FIG. 10 interposed in a housing space defined between a pillar garnish as a vehicle interior member and a pillar as a vehicle body component, and a passenger head that collides with the pillar garnish. It is sectional drawing shown in the implementation state which aimed at the impact relaxation.

FIG. 12 is an apparatus configuration diagram of a head form impactor for performing a head impact test.

[Explanation of symbols]

 Reference Signs List 10 pillar garnish (vehicle interior member) 12 pillar (vehicle component member) 18 occupant head 30 shock absorbing member 34 first outer surface 36 second outer surface 38 space 40 continuous portion H thickness S urethane stress

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiyuki Koyama 3-136 Imaikecho, Anjo-shi, Aichi Pref. Inoac Corporation Anjo Office (72) Inventor Nobuhiro Nakata 3-1-1 Imaikecho, Anjo-shi, Aichi Prefecture No. 36 INOAC CORPORATION Anjo Office F-term (reference) 3D023 BA07 BB09 BD08 BE02

Claims (3)

[Claims] 1. A vehicle interior member (10) and a vehicle body component (12) which are made of a shock absorbing member (30) of a required thickness (H) made of polyurethane foam or the like, and are installed in a passenger compartment of a vehicle.
Between the vehicle interior member (10) and the vehicle interior member (10) to reduce the impact of the occupant's head (18). A space portion (38) opening on the outer surface (34) facing the side of (10) and extending in the same or substantially the same direction as the collision direction of the occupant head (18) is provided in the main body.
(32), a plurality of holes are drilled at predetermined intervals at predetermined intervals, and when the vehicle interior member (10) is deformed due to the collision of the occupant head (18), the space portions (38) The continuous portion (40) located between them is crushed and deformed, so that the shock energy absorbing performance can be improved more than the shock absorbing member of the same thickness (H) without the space (38). A shock energy absorbing structure for a shock absorbing member, characterized in that: 2. The method according to claim 1, wherein the shock absorbing member (30) has a urethane stress.
2. The impact energy absorbing structure for an impact absorbing member according to claim 1, wherein (S) is formed of a polyurethane foam of 0.4 to 0.9 MPa. 3. Each of the space portions (38) is provided in the vehicle body component.
3. The shock absorbing member (30) according to claim 1 or 2, wherein the shock absorbing member (30) is formed in a through hole shape that opens to both outer surfaces (34, 36). Impact energy absorbing structure of impact absorbing member.