JPH08108812A - Resin made automobile shock absorber member - Google Patents

Abstract

PURPOSE: To provide a resin made automobile shock absorber member not only having a sufficient shock absorbing function but also limited deformation at the time of shock and light in weight. CONSTITUTION: A resin made automobile shock absorber member such as a bumper beam 10 formed of a lengthy member 11 consisting of a hollow part has a plurality of recesses 30 formed by arranging them on the surface 21 of the lengthy member 11 in the longitudinal direction in zigzag. Variety of shock conditions are satisfied by absorbing the energy at the time of the shock by the portion where the plurality of recesses 30 are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin shock-absorbing member for automobiles, which can be used for bumpers, bumper beams and the like.

[0002]

BACKGROUND ART Conventionally, metal shock absorbers such as bumpers and bumper beams have been widely used. This metal bumper or the like has no problem in strength, but has drawbacks such as large weight and easy corrosion.
Therefore, in recent years, plastic bumpers and the like have been adopted from the viewpoint of resource saving and weight reduction.

Such a plastic bumper or the like is usually manufactured by injection molding. However, in the production by injection molding, there is a problem that a molding machine becomes large because a bumper or the like is a relatively large molded product, or a mold becomes expensive because a high injection molding pressure is required. there were. Furthermore, in the case of manufacturing by injection molding, although the outer shape of the molded product can be designed relatively freely by changing the shape of the cavity of the mold, it is possible to use a bumper or the like having a hollow structure that can effectively perform shock absorption. Manufacturing was difficult.

On the other hand, various shock absorbing members for automobiles having a hollow structure, which are manufactured by blow molding, have been proposed in order to effectively carry out shock absorbing (Japanese Patent Laid-Open No. 4-42).
120145, etc.). FIG. 18 shows a cross-section orthogonal to the longitudinal direction of a bumper beam 90 which is an example of an automobile shock absorbing member having such a hollow structure.
The bumper beam 90 has such a cross-sectional shape continuously formed in the longitudinal direction. Since the bumper beam 90 has the hollow portion 91, the hollow portion 91 can absorb the shock.

[0005]

However, in the shock absorbing member for automobiles having a hollow structure manufactured by the blow molding described above, the structure and the shape are compared as shown in FIG. 18 due to the peculiarity of the molding method. There were many simple ones. In recent years, automobile bumpers and the like have been strongly demanded to be lightweight, and requirements for safety measures have become more diverse and stricter. It has become difficult to fully meet all of these requirements, and there is a shock absorbing member for automobiles that can achieve further weight reduction and can pass various tests assuming actual collisions. Was wanted.

Further, in order to pass the standard tests such as the 5MPH pendulum test, the barrier test, the pole test and the general tests, for example, in the front position of the front portion 92 of the bumper beam 90 shown in FIG. It is conceivable to take measures such as using a bumper with energy absorbing parts 93 such as foam or increasing the wall thickness of the bumper beam 90. However, these measures result in high price or increase in weight. There is a problem such as doing. Therefore, it is not possible to meet all of the above-mentioned requests.

An object of the present invention is to provide a shock absorbing member made of a resin, which has a sufficient shock absorbing function, has a small amount of deformation at the time of impact, and is lightweight.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to achieve the above object by providing the surface portion of a long member with a special structure. Specifically, the resin shock-absorbing member for automobiles of the present invention is formed by a long member having a hollow portion, and a plurality of concave portions are arranged in a zigzag pattern along the longitudinal direction on the surface portion of the long member. It is characterized by being formed. Here, the front surface portion is a portion excluding a portion (rear surface portion) attached to the vehicle body, and includes a portion on the front surface side of the vehicle and an upper surface portion and a lower surface portion. However, the front side does not mean the traveling direction of the automobile, and when the resin shock absorbing member for automobiles is attached to the rear instead of the front, it is a face opposite to the traveling direction.

It is desirable from the standpoint of strength that at least one of the plurality of recesses is arranged and formed so as to extend beyond the center line along the longitudinal direction of the elongated member. here,
“Arrangement and formation across the center line” means arrangement and formation across the center line. Then, at least one of the plurality of recesses is preferably bonded to the back surface of the elongated member in terms of strength, and particularly, all the recesses are preferably bonded to the back surface. Further, the strength may be further improved by forming ribs on the back surface of the long member or inserting a reinforcing core material into the back surface of the long member.

Blow molding is preferable as the method of molding the resin shock-absorbing member for automobiles of the present invention described above, but if a desired shape can be obtained, for example, a gas injection molding method (hollow injection molding). Other molding methods such as molding method) may be used. Here, as the material used for blow molding,
It can be arbitrarily selected from the thermoplastic resins conventionally used as materials for bumper and other resin shock-absorbing members for automobiles. For example, polypropylene, high density polyethylene, linear low density polyethylene, polyvinyl chloride,
Thermoplastic resins such as polycarbonate, polyamide, polyethylene terephthalate, polystyrene, polyoxymethylene, ABS resin, AS resin, polyphenylene ether, polyphenylene sulfide, and ethylene / propylene rubber, ethylene / propylene
As rubbers such as diene three-dimensional rubber and / or fillers, ones in which glass fiber, carbon fiber, talc, mica, calcium carbonate and the like are blended can be mentioned. A plurality of these resins, rubbers, fillers, etc. may be blended as necessary.

However, as a material for blow-molding a resin shock-absorbing member for automobiles having a specific shape as in the present invention, molding processability, physical properties of a molded article, impact resistance, mechanical strength such as pinch-off strength, etc. In this regard, a particularly suitable material is a melt index [230 ° C., 2.16 kgf]
Of 2.0 g / 10 min or less, isotactic pentad fraction of 93 mol% or more, or propylene homopolymer having a melt index of 2.0 g / 10 min or less, ethylene unit content of 15% by weight or less, propylene homopolymerization Parts of isotactic pentad fraction 93 mol% or more propylene block copolymers, or these propylene polymers and high-density polyethylene, ethylene / propylene elastomer, ethylene / α-olefin (other than propylene) elastomer, It is a composition with one or more selected from elastomers such as ethylene / propylene / diene elastomer and fillers such as talc.
Here, it is used in the range of 60 to 99% by weight of propylene polymer, 0 to 30% by weight of high-density polyethylene, 0 to 20% by weight of ethylene / α-olefin elastomer, and 0 to 40% by weight of filler such as talc. . Further, in this composition, if desired, maleic anhydride modified polyolefin, polar group-containing thermoplastic resin such as acrylic acid modified polyolefin, calcium carbonate, mica, glass fiber, inorganic filler such as carbon fiber, Alternatively, it may contain various additives such as an antioxidant, an ultraviolet absorber, a heat stabilizer, a lubricant, a flame retardant and a coloring agent.

[0012]

In the present invention as described above, the energy at the time of impact is absorbed by the plurality of recesses arranged in a staggered manner. At this time, the side walls of the plurality of recesses (particularly, the side walls extending in the direction orthogonal to the longitudinal direction of the resin shock absorber for automobiles).
However, since it plays the role of a rib, a desired shock absorbing function can be obtained while securing a certain strength. Further, the long member is not particularly limited, but it is preferable that at least both end portions have curved portions, and such a curved shape makes it easier for the entire long member to receive impact force. , A better shock absorbing function can be obtained. Therefore, as compared with the conventional case where the shock absorbing is performed only by the hollow portion, an excellent shock absorbing function that can satisfy various shock conditions can be obtained. Further, in order to improve the shock absorbing function, it is not necessary to separately provide an energy absorbing component or increase the wall thickness of the member, so that cost reduction and weight reduction are achieved, and thereby the above-mentioned object is achieved. .

Further, when at least one, preferably all, of the plurality of recesses are arranged and formed so as to cross the center line along the longitudinal direction of the elongated member, a side wall which functions as a rib is suitable. Since a sufficient length is secured, an even more excellent shock absorbing function can be obtained. Furthermore, if at least one, preferably all, of the plurality of recesses are joined to the back surface of the elongated member, the strength can be improved. And
When the recess is arranged and formed so as to cross the center line as described above, the connection between the recess and the back surface can be easily realized. Further, strength can be further improved by forming ribs on the back surface of the long member or inserting a reinforcing core material on the back surface of the long member.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a perspective view of a bumper beam 10 which is a resin shock-absorbing member for automobiles according to a first embodiment of the present invention. FIGS. 2 and 3 show the bumper beam 10 respectively. Front view and top view (viewed from arrow Z in FIG. 2)
It is shown. Further, FIGS. 4, 5, and 6 show cross-sections in the longitudinal direction of the bumper beam 10 taken along the lines AA, BB, and CC in FIG. 2, respectively. The bumper beam 10 is a blow molded product,
As shown in FIGS. 1 to 3, it is formed by a long member 11 extending in the left-right direction in the drawings and having curved portions at both end portions. Mounting surfaces 12 (not shown) for mounting on the vehicle body are formed on the back surfaces (lower sides in FIG. 3) of both ends of the long member 11 in the longitudinal direction. An appropriate number of embedded bolts 13 are provided on the mounting surface 12.

Inside the elongated member 11, as shown in FIGS. 4 to 6, a hollow portion 20 is formed over the entire length of the elongated member 11. On the surface portion 21 (front surface portion 22, upper surface portion 23, and lower surface portion 24) of the long member 11, a plurality of recesses 30 are arranged in a staggered pattern along the longitudinal direction of the long member 11. That is, the front surface portion 22 and the upper surface portion 23
Four concave portions 30 are arranged and formed at a corner portion (upper side position in FIG. 2) of FIG. 2 and a corner portion between the front surface portion 22 and the lower surface portion 24 (FIG. 2).
Three recesses 30 are arranged and formed in the middle lower position), and these recesses 30 are alternately arranged on the upper surface 23 side and the lower surface 24 side.

Each of the recesses 30 is formed in a substantially rectangular shape as viewed from the front surface portion 22 side, and the center line in the longitudinal direction of the elongated member 11 from the upper and lower edge positions of the front surface portion 22 (see FIG. 2).
It is formed up to a position beyond the one-dot chain line K). Further, the dimension S of each recess 30 beyond the center line K is 0 to
It is preferably about 50 mm, more preferably 10 to 30 m
m.

Further, the longitudinal width W of each recess 30 (see FIG. 2) is determined by the diameter (7 inch) of the test pole described later.
= 178 mm), preferably 5
0 to 150 mm is preferable, more preferably 80 to 13 mm
It is about 0 mm. The depth L1 of each recess 30 (see FIG. 4) is relative to the width L from the flat portion of the front surface portion 22 of the bumper beam 10 to the flat portion of the back surface portion 25.
L1 = 1 / 5L to 1 / 2L is preferable, and more preferably L1 = 1 / 4L to 1 / 3L. The width L
Is determined according to the type (size, weight, etc.) of the automobile body to which the bumper beam 10 is attached.

A projecting portion 26 projecting toward the front surface portion 22 is formed on the rear surface 25 (mounting side of the automobile body) of the elongated member 11, and the tip 26A of this projecting portion 26 has a recess 30 formed therein.
Is joined to. In addition, inside the protrusion 26,
As shown in FIG. 6, a hollow reinforcing core material 40 is inserted. The reinforcing core material 40 is provided over substantially the entire length of the long member 11 in the longitudinal direction, and is arranged up to the position of the mounting surface 12 as shown by the alternate long and short dash line in FIG. 3. However, it is not always necessary to dispose up to the position of the mounting surface 12. The shape of the reinforcing core material to be inserted in the present invention is not limited to such a shape and may be any shape.

The material of the reinforcing core material 40 is not particularly limited, but is, for example, JP-A-5-239286.
The following can be used according to the one proposed in the issue. (A) Propylene homopolymer or propylene-ethylene copolymer 2 having a melt index of 300 g / 10 minutes or more
5 to 70 parts by weight of pellets composed of 0 to 60% by weight and 80 to 40% by weight of glass fiber, having a pellet length of 2 to 20 mm, and the glass fiber length being substantially equal to the pellet length; Mix with 95 to 30 parts by weight of a propylene homopolymer or propylene-ethylene copolymer having an index of 3 to 20 g / 10 minutes and an isotactic pentad fraction of 93 mol% or more so that the total amount becomes 100 parts by weight. Or a propylene homopolymer or propylene-ethylene copolymer having a melt index of 300 g / 10 minutes or more (A ') and 20 to 60% by weight of glass fiber and 80 to 40% by weight of glass fiber. An acid addition amount of 0.
1 to 10% by weight of an acid-modified polyolefin, which is 1 to 10 parts by weight, and has a pellet length of 2 to 20 mm, and
Pellet 5 whose glass fiber length is substantially equal to the pellet length
~ 70 parts by weight and (B) melt index of 3 to 20
Isotactic pentad fraction is 93 at g / 10 minutes
A glass fiber reinforced polyolefin resin composition is obtained by mixing 95% by weight or more of propylene homopolymer or 95% by weight of propylene-ethylene copolymer so that the total amount becomes 100 parts by weight. As the reinforcing core material, in addition to such a glass fiber reinforced polyolefin resin composition, a resin formed only, a resin composition containing a filler, a fiber reinforced thermosetting resin (GFRP), a metal You may use what was formed by the.

In the first embodiment, the bumper beam 10 is manufactured by blow molding as follows. First, a molding die (not shown) having a cavity according to the outer shape of the bumper beam 10 is prepared. A cavity having a surface shape corresponding to each recess 30 is formed in this molding die. Next, the reinforcing core material 40 that has been molded in advance is attached to the inside of the cavity of the molding die. After that, the cylindrical parison is sandwiched by the molding die from the outside, and air is blown into the cavity inside the parison to expand the parison so that the parison is in close contact with the cavity surface of the molding die and the reinforcing core material 40. . Then, the molding die is opened to complete the bumper beam 10
Take out. At this time, the reinforcing core material 40 is also integrated and taken out as the bumper beam 10.

According to such a first embodiment, the following effects can be obtained. That is, since the surface portion 21 of the bumper beam 10 is provided with the plurality of recesses 30 arranged in a staggered pattern, the energy at the time of impact is provided by the portion (honeycomb structure portion) in which the plurality of recesses 30 are formed. Can be absorbed. The sidewalls of the plurality of recesses 30 (particularly, the sidewalls 3 extending in the direction orthogonal to the longitudinal direction of the bumper beam 10).
Since 1) plays a role of a rib, a desired shock absorbing function can be obtained while securing a certain strength. Therefore, it is possible to obtain an excellent shock absorbing function capable of satisfying various shock conditions, as compared with the conventional case where the shock absorbing is performed only by the hollow portion.

Further, in order to improve the shock absorbing function, a component for absorbing energy (for example, component 9 in FIG. 18).
Since it is not necessary to separately provide 3) or to increase the thickness of the member, cost reduction and weight reduction can be achieved.

Furthermore, since the plurality of recesses 30 are arranged in a zigzag manner, the side walls 31 are arranged at appropriate intervals and substantially evenly on the upper and lower sides, so that the entire bumper beam 10 is excellent. It is possible to obtain a shock absorbing function.
Since each of the recesses 30 is formed to a position beyond the center line K (see FIG. 2) along the longitudinal direction, the side wall 31 having an appropriate length can be secured, and the shock absorbing effect is further improved. You can get the function.

The longitudinal width W of each recess 30 (see FIG. 2)
That is, since the distance between the side walls 31 of the recess 30 facing each other is smaller than the diameter of the test pole described later, the impact is excellent even against a local impact such as a collision with the pole. It can exert a buffering function.

Further, since each recess 30 is connected to the tip 26A of the protrusion 26 which is a part of the back surface 25,
The strength of the bumper beam 10 can be improved.
Since each of the recesses 30 is arranged and formed so as to extend beyond the center line K, each of the recesses 30 and the protrusion 2 as described above is formed.
It is possible to easily realize the connection of the tip 6 with the tip 26A.

Further, since the reinforcing core material 40 made of, for example, a fiber composite material is inserted inside the protruding portion 26, the strength of the bumper beam 10 can be further improved.

[Second Embodiment] FIGS. 7 to 9 show a bumper beam 50 which is a resin shock-absorbing member for automobiles according to a second embodiment of the present invention. A top view of the bumper beam 50 is shown in FIG. 7, and the bumper beam 5 is shown in FIG.
0 is a perspective view as viewed from the back surface side, and FIG. 9 shows a cross-section orthogonal to the longitudinal direction of the bumper beam 50 along the line D-D in FIG. 7. The bumper beam 50 has substantially the same configuration as that of the bumper beam 10 of the first embodiment, and only the configuration of the back surface portion 25 is partially different. It is omitted, and only different parts will be described below.

In the bumper beam 10 of the first embodiment, the reinforcing core material 40 is inserted inside the protruding portion 26, but in the bumper beam 50 of the second embodiment,
The reinforcing core material 40 is not inserted inside the protruding portion 51. Further, unlike the protrusion 26 of the first embodiment, the protrusion 51 of the second embodiment is not formed to the position of the mounting surface 12. Inside the protrusion 51, four ribs 52 extending in a direction orthogonal to the longitudinal direction of the bumper beam 50 are provided at appropriate intervals.

According to the second embodiment, since the rib 52 is provided in place of the reinforcing core material 40 of the first embodiment, an excellent shock absorbing effect can be obtained as in the first embodiment. There is an effect that the function and strength can be obtained.

[Comparative Experiment] In order to confirm the effect of the present invention, the following 5MPH pendulum test, 5
Comparative experiments were conducted by the MPH barrier test and the 5MPH pole test. As an experimental example of the present invention, when the reinforcing core member 40 is not provided in the bumper beam 10 of the first embodiment (Experimental Example 1), in the case of the bumper beam 50 having the rib 52 of the second embodiment ( Experimental example 2), the bumper beam 10 having the reinforcing core material 40 of the first embodiment
The case (Experimental example 3) was prepared. On the other hand, as a comparative example,
The bumper beam 90 having the cross-sectional shape of FIG. 18 described above.
In this case (Comparative Example 1), a case (Comparative Example 2) having a bumper beam 96 having protrusions 95 on the front side as shown in the sectional shape of FIG. 19 was prepared.

As the raw material resin for the Pamper beams of each of Experimental Examples 1 to 3 and Comparative Examples 1 and 2, (1) 65 weight parts of polypropylene (E250G, manufactured by Idemitsu Petrochemical Co., Ltd.) with a melt index of 1 g / 10 min. %, (2) 20% by weight of high-density polyethylene (750 LB, manufactured by Idemitsu Petrochemical Co., Ltd.) with a melt index of 0.03 g / 10 min, and (3) Mooney viscosity [ML _{1 + 4} (100 ° C.)] =
77, ethylene-propylene elastomer with an ethylene content of 73% by weight (EP07P, manufactured by Japan Synthetic Rubber Co., Ltd.)
A resin composition containing 5% by weight and (4) 10% by weight of talc having an average particle size of 1.5 μm and an average aspect ratio of 15 was used.

The molding conditions and temperature conditions are as follows. [Molding conditions] Molding machine: 90 mmφ Die: 100 mmφ Accumulator: 25 liters Mold clamping pressure: 60 ton Screw rotation speed: 40 rpm Motor load: 115A

[Temperature Conditions] Cylinder No. 1: 230 ° C. No. 2: 210 ° C. No. 3: 190 ° C. No. 4: 190 ° C. Crosshead No. 1: 190 ° C. No. 2: 190 ° C. No. 3: 190 ° C. Die No. 1: 190 ° C. No. 2: 190 ° C Molding cycle: 200sec Mold temperature: 28 ° C Resin temperature: 225 ° C

Experimental Examples 1 to 3 molded in this way
The bumper beam of each of Comparative Examples 1 and 2 was used as a test object, and the product weight was 4.5 kg, the product length was 1.4 m, the vehicle weight was 1200 kg, and the room temperature was 5 MPH (impact speed 8 km / H.
r = 5mile / Hr) pendulum test (upper and lower strokes, 35mm), barrier test, pole test (diameter 7in
ch) each standard test was performed, and the maximum deformation amount, the maximum generated load, and the presence or absence of slippage were examined for each of Experimental Examples 1 to 3 and Comparative Examples 1 and 2, and a comprehensive evaluation was performed. The results of this comparative experiment are shown in the following Tables 1 to 3 and FIGS. 10 to 12. Tables 1, 2, and 3 show the results of the pendulum test, barrier test, and pole test, respectively. Further, FIGS. 10, 11 and 12 show the relationship between the amount of deformation and the generated load in the pendulum test, the barrier test and the pole test, respectively.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

According to Tables 1 to 3, in each of Experimental Examples 1 to 3, the maximum deformation amount is small in all the tests, the maximum generated load is large, and the comprehensive evaluation is good. In Comparative Examples 1 and 2, the overall evaluation is bad except that the overall evaluation is good in the pendulum test of Comparative Example 2. Further, in Comparative Example 2 as well, the overall evaluation is poor in other barrier tests and pole tests, so it can be said that the performance is insufficient.

Further, according to FIG. 10, in Comparative Example 1 indicated by the dotted line in the figure, the amount of deformation due to sliding of the pendulum lid is large, whereas in Comparative Example 2 indicated by the dashed line in the figure, Slip is prevented by the protrusions 95 in 19 being crushed, and in Experimental Example 1 shown by the solid line in the figure, the portion where the plurality of recesses 30 are formed (honeycomb structure portion) partially absorbs energy. It can be seen that it is deformed and slippage is prevented. Further, according to FIG. 11, in Comparative Example 1 indicated by the dotted line in the figure, the entire bumper beam is suddenly subjected to a load and the defective portion of the bumper beam is buckled, resulting in a small generated load and a large deformation amount. On the other hand, in Experimental Example 1 shown by the solid line in the figure, the load gradually rises in the portion where the plurality of concave portions 30 are formed (honeycomb structure portion), and uniform stress is applied to the whole, and finally the generated load is generated. It can be seen that is large and the amount of deformation is small.

According to FIG. 12, in Comparative Example 1 indicated by the dotted line in the figure, stress locally concentrates and buckling occurs early, resulting in a small load and a large deformation amount. On the other hand, in Experimental Example 1 shown by the solid line in the figure, it can be seen that the portion in which the plurality of recesses 30 are formed (honeycomb structure portion) receives stress in a wide range, the generated load is large and the deformation amount is small. From the results of the above comparative experiments, it was shown that the bumper beam according to the present invention has an excellent shock absorbing function and strength and can sufficiently cope with various tests, and the effect of the present invention was remarkably shown.

The present invention is not limited to the above-described embodiments, but includes other configurations that can achieve the object of the present invention, and the following modifications and the like are also included in the present invention. . That is, in the first and second embodiments, the reinforcing core member 40 and the reinforcing core member 40 are provided inside the protrusions 26 and 51, respectively.
Although the rib 52 is provided, both the reinforcing core material and the rib may be provided inside the protrusion. Further, the reinforcing core material 40 and the ribs 52 are not always necessary and may be omitted depending on their use, but it is preferable to provide them in terms of strength. Furthermore, the ribs formed on the back surface of the resin shock-absorbing member for automobiles of the present invention are not limited to the ribs 52 having the shape as in the second embodiment, and for example, as shown in FIG. The rib 60 may have a shape.

In each of the above embodiments, a total of seven recesses 30 are provided, but the number of recesses 30 may be arbitrary as long as the recesses 30 are arranged in a staggered pattern.
Further, in each of the above-described embodiments, the shape of each recess 30 is a substantially rectangular shape when viewed from the front face portion 22 side, but the shape of the recess is arbitrary, for example, as shown in FIG. 14, a substantially trapezoidal shape. The concave portion 71 may be a concave portion 71, a concave portion 72 having a substantially triangular shape as shown in FIG. 15, or a concave portion 73 having a substantially semicircular shape as shown in FIG. 16, that is, a plurality of concave portions are arranged in a staggered pattern. It should have been done.

In each of the above embodiments, each recess 30
Was formed so as to extend from the front surface portion 22 to the upper surface portion 23 or the lower surface portion 24, but as shown in FIG.
The recess 74 may be formed only in the above.

[0044]

As described above, according to the present invention, a plurality of recesses arranged in a staggered manner can absorb energy at the time of impact, and the side walls of each recess play a role of ribs. An excellent shock absorbing function and strength that can satisfy the shock condition can be obtained, and since it is not necessary to increase the wall thickness of the member, there is an effect that weight reduction and cost reduction can be achieved.

Further, when at least one of the plurality of recesses is arranged and formed so as to extend beyond the center line along the longitudinal direction of the elongated member, the side wall which plays the role of the rib is secured to have an appropriate length. Therefore, there is an effect that a more excellent shock absorbing function can be obtained. If at least both ends of the long member are curved, the impact force can be dispersed. further,
When at least one of the plurality of recesses is joined to the back surface of the elongated member, there is an effect that the strength can be further improved.

Further, when ribs are formed on the back surface of the long member, or when a reinforcing core material made of a fiber composite material or the like is inserted on the back surface of the long member, the strength is also improved by these. The effect is that it can be further improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a bumper beam according to a first embodiment of the present invention.

FIG. 2 is a front view of the bumper beam of the first embodiment.

FIG. 3 is a top view of the bumper beam of the first embodiment.

FIG. 4 is a sectional view of the bumper beam of the first embodiment taken along the line AA in FIG.

FIG. 5 is a cross-sectional view of the bumper beam of the first embodiment taken along line BB in FIG.

FIG. 6 is a sectional view of the bumper beam of the first embodiment taken along the line CC in FIG.

FIG. 7 is a top view of the bumper beam of the second embodiment of the present invention.

FIG. 8 is a perspective view of the bumper beam of the second embodiment as viewed from the back surface side.

FIG. 9 is a cross-sectional view of the bumper beam of the second embodiment taken along line D-D in FIG. 7.

FIG. 10 is a result diagram of a comparative experiment (pendulum test).

FIG. 11 is a result diagram of a comparative experiment (barrier test).

FIG. 12 is a result diagram of a comparative experiment (pole test).

FIG. 13 is a rear view showing a first modified example of the present invention.

FIG. 14 is a front view showing a second modified example of the present invention.

FIG. 15 is a front view showing a third modified example of the present invention.

FIG. 16 is a front view showing a fourth modified example of the present invention.

FIG. 17 is a front view showing a fifth modified example of the present invention.

FIG. 18 is a cross-sectional view showing a conventional example (Comparative example 1).

FIG. 19 is a cross-sectional view showing Comparative Example 2.

[Explanation of symbols]

10, 50 Bumper beam which is a shock absorbing member made of resin for automobiles 11 Long member 20 Hollow part 21 Surface part 22 Front part forming surface part 23 Upper surface part forming surface part 24 Lower surface part forming surface part 25 Back surface Part 26,51 Projection part which constitutes the back surface part 30,71,72,73,74 Recess 40 Core material 52,60 Rib K Center line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiko Tada 1 Anesaki Kaigan, Ichihara-shi, Chiba 1 Idemitsu Petrochemical Co., Ltd. (72) Inventor Naonari Fukuhara 447 Sanyo-cho, Akagun-gun, Okayama (72) Inventor Kenichi Akamatsu 447 Shimo-shi, Sanyo-cho, Akaban-gun, Okayama Minorukasei Co., Ltd.

Claims (5)

[Claims] 1. A resin automobile, comprising a long member having a hollow portion, and a plurality of recesses arranged in a staggered pattern along the longitudinal direction on the surface of the long member. Shock absorbing member for use. 2. The resin shock-absorbing member for automobiles according to claim 1, wherein at least one of the plurality of recesses is arranged and formed beyond a center line along the longitudinal direction of the elongated member. A shock-absorbing member for automobiles, which is characterized in that 3. The resin shock-absorbing member for automobiles according to claim 1 or 2, wherein at least one of the plurality of recesses is coupled to a back surface portion of the elongated member. Characteristic resin shock-absorbing member for automobiles. 4. A resin automobile shock-cushioning member according to any one of claims 1 to 3, wherein a rib is formed on the back surface of the elongated member. Shock absorbing member for use. 5. The resin shock-absorbing member for automobiles according to any one of claims 1 to 4, wherein a reinforcing core material is inserted into the back surface of the elongated member. A shock absorbing member made of resin for automobiles.