JP2000240706A - Energy absorbing member and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy absorbing member realizing a favorable energy absorbing performance, and being excellent even in productivity, and its manufacturing process as well as an automobile skeletal material. SOLUTION: This energy absorbing member 100 is formed into a peak type of its vertically upward end 100t, at one end, on a drawing, having two fiber reinforced plastic layers 10 and 20 and the structure of a laminated tube layer with these plastic layers. In reference to orientation of the reinforced fiber, it is desirable that the orientative angle θ is controlled so as to be ±10 deg. to ±45 deg. at the respective layers 10, 20 and the layer 10, where a direction of the peak end 100t of an axis is set to 0 deg., an orientative angle made up by the axis and the reinforced fiber is set to be θ, and a negative sign is put to an inner side of the laminated tube in the orientative angle θ, and a positive sign is put to the outer side of the laminated tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy absorbing member and a method of manufacturing the same, and more particularly, to a laminated structure in which a high toughness thermoplastic resin is used as a matrix resin and a high strength layer is sandwiched between low layers. Therefore, the energy absorption amount is large, and because the injection molding method can be applied, the energy absorbing member having high productivity and the method of manufacturing the same, for example, vehicles and the like where durability and safety are required It is used for impact action parts, and absorbs energy at the time of collision or the like in a suitable manner to reduce the impact force.

[0002]

2. Description of the Related Art In recent years, various studies have been made on cylindrical energy absorbers to be disposed at impact sites such as vehicles. For example,
JP-A-5-332385, JP-A-5-33238
Japanese Patent Application Laid-Open No. 6-1994 proposes a cylindrical energy absorber having a side surface inclined for use in a bumper stay, a shape in which one end is cut off obliquely, and a two-stage plate shape.
However, these are filament winding
"FW". ) Due to the molding method, the productivity is poor. In addition, since the matrix resin of the fiber-reinforced resin used is a thermosetting resin, the toughness is low and the energy absorption performance is lower than that of a thermoplastic resin having high toughness. Low.

[0003] JP-A-6-123322, JP-A-6-123322
JP-A-123323 and JP-A-06-26494 propose a short fiber reinforced cylindrical energy absorber for bumper stays with improved productivity, but the energy absorption performance is not yet sufficient. In addition, Japanese Unexamined Patent Publication
In the technique described in Japanese Patent No. 30068, a high energy absorption amount is achieved by laminating a high-strength reinforcing fiber layer and a high-modulus reinforcing fiber layer.
Productivity is poor because of the use of the W forming method.

Further, in the technology described in Japanese Patent Application Laid-Open No. 8-177922, in an energy absorber of a fiber-reinforced composite material, stabilization and absorption of energy absorption are achieved by a laminated structure (hybridization) having different fiber types / fiber blends. An increase in volume has been achieved. However, since the reinforcing fiber is a continuous fiber, the molding method is a FW molding method with low productivity and is expensive, and the use of a sheet winding method in some cases suggests a slight improvement in productivity. However, at the same time, there is a concern that the energy absorption performance may be reduced due to the reduced adhesion at the lamination interface.

Further, Japanese Patent Application Laid-Open No. H10-95035 discloses that a fiber in an injected resin is rotated by arbitrarily controlling the angle, speed, torque and timing of a rotating body of a mold during injection molding. A technique for orienting is disclosed, but there is no description about two-color molding, in which a pair of cylinders is used to simultaneously or sequentially inject two types of materials into a common mold, and a stacked structure is formed. The concept is not disclosed.

[0006]

As described above, in the conventional energy absorbers, a certain energy absorption performance is realized by the continuous fiber reinforcement, but these must be obtained by the FW molding method. As a result, the productivity is poor, while the fiber-reinforced thermoplastic resin allows the application of the injection molding method to improve the productivity, but the current shape and structure do not have sufficient energy absorption performance. was there.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to realize an energy absorbing member which realizes good energy absorbing performance and is excellent in productivity. , A manufacturing method thereof, and a frame material for an automobile.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that a fiber-reinforced resin layer in which the orientation of reinforcing fibers is controlled is appropriately laminated, and the entirety, particularly at the end portions. Has been found to be able to solve the above-mentioned problems by making the shape into a predetermined shape, and the present invention has been completed.

That is, the energy absorbing member of the present invention is a laminated tubular energy absorbing member formed by laminating a plurality of fiber reinforced resin layers made of a fiber reinforced resin in which reinforcing fibers are dispersed in a matrix resin. Is oriented at an arbitrary angle with respect to the axis of the laminated tube, and decreases as the thickness of the tube wall of the laminated tube approaches one end,
It is characterized in that one end has a pointed shape.

In a preferred form of the energy absorbing member of the present invention, in a cross section passing through and parallel to the axis of the laminated tube, the one end direction of the axis is set to 0 °, and the axis and the reinforcing fiber are formed. Of the orientation angles, the angle formed on the inner side of the laminated tube is indicated by a negative value, and the angle formed on the outer side is indicated by a positive value.゜ to ± 45 °, and the orientation angle in the cross section of the other tube wall is − (± 10 ° to ± 45 °).

Further, another preferred embodiment of the energy absorbing member of the present invention is characterized in that the sign of the orientation angle of the reinforcing fiber is reversed in the adjacent fiber reinforced resin layer. .

In still another preferred form of the energy absorbing member of the present invention, the pointed shape is defined by a taper in which the outer wall thickness of the tube wall is reduced, and the taper angle is three.
0 to 75 °.

In another preferred form of the energy absorbing member of the present invention, the matrix resin is polypropylene and / or polyamide, and the content thereof is 25 to 90.
%, Wherein the reinforcing fibers are glass fibers and / or carbon fibers, and the content thereof is 75 to 10% by weight.

Further, still another preferred embodiment of the energy absorbing member of the present invention is formed by laminating three fiber-reinforced resin layers in which the matrix resin is polyamide and the reinforcing fibers are glass fibers. A fiber reinforced resin layer having a glass fiber content of 40 to 50% by weight is inserted between two fiber reinforced resin layers having an amount of 20 to 30% by weight.

[0015] A skeletal material for an automobile according to the present invention is provided with the energy absorbing member as described above.

Further, in the method of manufacturing an energy absorbing member according to the present invention, in manufacturing the energy absorbing member as described above, a core portion having a plurality of concentrically arranged cylindrical cores, and the core portion may be arbitrarily selected. A mold having a rotation control device for rotating at a rotation angle, speed, torque and timing is used. (1) The mold is filled with a first fiber reinforced resin of a plurality of fiber reinforced resins, After operating the portion to form a first fiber reinforced resin layer in which the reinforcing fibers are oriented, the first core provided at the outermost peripheral portion of the plurality of cylindrical cores is removed from the core portion, 2) Then,
After filling the second fiber reinforced resin to form the second fiber reinforced resin layer, the second core is removed from the core portion, and (3) the fiber reinforced resin to be formed in the step (1) or the step (2) is formed. It repeats according to the number of layers.

[0017]

In the present invention, the structure of the laminated tube is employed to control the orientation of the reinforcing fibers in the fiber reinforced resin constituting each layer of the energy absorbing member. Therefore, even if strong impact energy is received at the time of impact, excellent energy absorption performance is exhibited. Further, since one end of the laminated tube corresponding to the impact action portion has a predetermined pointed shape, it has good buckling resistance against impact energy.

Further, in the energy absorbing member of the present invention,
Since the matrix resin of the fiber reinforced resin constituting each layer is basically a thermoplastic resin, the toughness can be improved. In addition, since the energy absorbing member of the present invention can be manufactured by injection molding using two-color molding, not only can the adhesiveness and productivity of the lamination interface be improved, but a plurality of types of fiber-reinforced resins having different properties can be optionally used. It is possible to form a laminated structure in which a layer having good hardness and rigidity is sandwiched between layers having excellent toughness and flexibility, for example. It becomes possible to realize absorption characteristics.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the energy absorbing member of the present invention will be described in detail. As described above, the energy absorbing member of the present invention has a laminated pipe structure in which fiber-reinforced resin layers are laminated. In this laminated pipe structure, the thickness of the pipe wall decreases as approaching one end, and the one end is It has a pointed shape. The reinforcing fibers in the fiber reinforced resin layer are oriented at an arbitrary angle with respect to the axis of the laminated tube structure.

FIGS. 1 and 2 show typical examples of the energy absorbing member of the present invention. In this case, FIG. 1 shows the external shape of the present energy absorbing member, and FIG. 2 shows a cross section passing through the axis of the laminated tube and parallel to the axis. The energy absorbing member 100 has one end, that is, a vertically upward end 100t in the drawing, having a pointed shape, and has a laminated pipe structure in which the fiber reinforced resin layers 10, 20, and 10 are sequentially laminated. Focusing on the tube wall structure of the laminated tube, the fiber reinforced resin layer 20 is formed of the fiber reinforced resin layers 10 and 1 having different characteristics.
It can be said that a structure sandwiched by 0 is adopted.

Here, the orientation of the reinforcing fibers described above is shown in FIG.
In FIG. 2 and FIG.
゜, the orientation angle between the axis and the reinforcing fiber is assumed to be θ. Of the orientation angles θ, those formed on the inner side of the laminated tube are denoted by negative signs, and those formed on the outer side of the laminated tube are denoted by positive signs. When,
The orientation angle θ is ± 1 in each of the layers 10, 20 and 10.
It is preferable that the angle is controlled to be 0 ° to ± 45 °. In addition, since the tube wall structure in the laminated tube is symmetrical with respect to the axis, the positive and negative signs given to θ in the tube wall cross section 100 (R) on the right side and the tube wall cross section 100 (L) on the left side in the drawing. If, for example, the orientation angle θ of the reinforcing fibers in each layer in the tube wall section 1 (R) is ± 10 ° to ± 45 °,
The orientation angle θ of the reinforcing fibers in each layer in the tube wall cross section 100 (L) is displayed as − (± 10 ° to 45 °). As shown in FIG. 2, the above relationship is such that the orientation angle of the reinforcing fiber GF (glass fiber) is -15 ° (layer 10) and + 15 ° in the tube wall 100 (R) in order from the inside of the laminated tube. (Layer 20) and −15 ° (Layer 10), whereas the tube wall 1
At 00 (L), + 15 ° (layer 1)
0), -15 ° (layer 20) and + 15 ° (layer 10).

In the energy absorbing member of the present invention, if the magnitude | θ | of the orientation angle θ deviates from the range of 10 ° to 45 °, the amount of energy absorption is significantly reduced and the energy absorbing member is buckled. May be undesirable. In addition, in this energy absorbing member, the sign of the orientation angle of the reinforcing fiber is reversed between the adjacent fiber reinforced resin layers, and the fact that the orientation direction of the reinforced resin is reversed indicates that the energy absorbing member has an adverse effect on energy absorption. preferable. For example,
In the tube wall 100 (R) in FIG. 2, the sign of the orientation angle θ between the layer 10 and the layer 20 is (−) in the layer 10 and (+) in the layer 20. is there. However, this condition does not limit the magnitude of the orientation angle θ, and it is sufficient if the sign is reversed. For example, θ is (+) 30 °, (−) between three adjacent layers. 20 ゜ and (+) 1
0 ° is also satisfied.

As for the orientation of the reinforcing fibers, since the energy absorbing member of the present invention is formed by the manufacturing method described later, in practice, the reinforcing fibers are three-dimensionally oriented in a manner of spirally ascending or descending the tube wall. It is thought that it has taken. Therefore, the orientation of the reinforcing fibers described above is, strictly, what defines the projection of the reinforcing fibers to the tube wall cross section, but in implementing the present invention, it is sufficient to define such projections. .

Next, the pointed end of the energy absorbing member of the present invention will be described. As shown in FIGS. 1 and 2, the pointed end 100t is formed in such a manner that the thickness of the tube wall of the laminated tube decreases as approaching the extreme end, so that the tube wall has a constant thickness. Is excluded. In the use state of the energy absorbing member of the present invention, the pointed end portion is disposed so as to face the impact direction, functions as an impact action portion, and suppresses buckling of the present absorbing member.

Such a pointed shape is usually formed by shaping the mold cavity itself or by grinding the intended end of the laminated tube at a predetermined angle. Is defined as a tapered shape in which the taper angle α shown in FIG.
Preferably it is 75 °. If you deviate from this range,
Buckling resistance may be significantly reduced, which is not preferable.

In the present invention, the "pointed shape" is sufficient if it satisfies the above-mentioned conditions. For example, the shape is such that the outer wall thickness of the tube wall gradually decreases and the inner diameter increases. You may. Further, the slope surface of the taper may be a curved surface, or may be a slightly stepped shape.

In the energy absorbing member of the present invention, the other end of the above-mentioned laminated tube may be provided with a bottom. In this case, for example, when the frame is fixed to a car as a frame member, it is more stable. There is an advantage that a fixed installation can be performed. Further, the overall shape of the laminated tube can be substantially frusto-conical. In this case, since the breakage from the tip portion occurs stably, the advantage that stable energy absorption can be obtained is obtained.

Next, the fiber reinforced resin layer constituting the above-described laminated pipe structure and the fiber reinforced resin used for the layer will be described. In the present invention, as such a fiber-reinforced resin,
From the viewpoint of improving the toughness, those using a thermoplastic resin as a matrix resin are preferable, and specifically, those using polypropylene and / or polyamide as a matrix resin and reinforcing fibers as glass fibers and / or carbon fibers are preferable. .

The content of polypropylene and / or polyamide in the fiber reinforced resin is preferably 25 to 90% by weight. If it is less than 25% by weight, buckling tends to occur and energy absorption may be unstable. If it exceeds 90% by weight, strength may be low and energy absorption may be unstable, which is not desirable. On the other hand, the content of glass fibers and / or carbon fibers is preferably set to 75 to 10% by weight.

The fiber length of the reinforcing fiber is preferably at least 10 mm, and if it is less than 10 mm, the amount of energy absorption may be insufficient, which is not desirable. Further, the fiber diameter of the reinforcing fibers is preferably set to 10 to 20 μm, and if it is out of this range, the amount of energy absorption may be insufficient, which is not desirable.

In the present invention, the properties of the fiber reinforced resin layer can be appropriately changed, and by appropriately laminating and arranging the fiber reinforced resin layers having different properties.
Desired characteristics can be imparted to the energy absorbing member. The different characteristics can be realized by changing the types and contents of the matrix resin and the reinforcing fibers, changing the orientation angle of the reinforcing fibers, and the like. The number of layers is 2
It is not particularly limited as long as it is the above, and it is needless to say that it is not necessary to have different characteristics for each layer.

As a typical example of the above-mentioned multilayer structure,
A three-layer structure in which a layer having high strength and good hardness and rigidity is sandwiched between layers having slightly low strength but excellent toughness and flexibility can be given, and according to this structure, a moderate shock absorption can be exhibited. easy. As a specific example of a simple structure, a structure in which a fiber reinforced resin in which glass fibers are dispersed in a polyamide resin and the strength of each layer is adjusted by the content of glass fibers can be given. A layer having an amount of 40 to 50% by weight and a reinforcing fiber content of 20 to 30%
Those having a structure sandwiched by layers by weight are preferred.

The energy absorbing member of the present invention described above is suitable for use as a pillar material of various skeletal materials, specifically, as a bumper stay or the like. Further, the skeleton material for an automobile of the present invention is a member having such an energy absorbing member, and specific examples thereof include a front side member, a rear side member, and a bumper.

Next, a method for manufacturing the energy absorbing member of the present invention will be described. FIG. 18 shows an example of a mold used in the manufacturing method of the present invention. In FIG.
Has a hollow cylindrical shape, accommodates a core portion composed of concentrically arranged cylindrical cores 2, 3 and 4, and has a cavity 5 formed between its inner wall and the core 2. . The core is rotatably accommodated by a rotating shaft 6 connected to a motor 7, and the rotation angle, speed, torque, and timing of the rotation are controlled by a rotation control unit 9.

In the manufacturing method of the present invention, a plurality of fiber reinforced resins are used as a molding material. First, the first fiber reinforced resin is filled into the cavity 5 of the mold 1 from the resin injection port 8 and the core is formed. By operating at a desired rotation angle, speed, torque and timing to form a first fiber reinforced resin layer in which reinforcing fibers are oriented, the cylindrical core 2 installed at the outermost peripheral portion is removed from the core portion. . (Step (1)). Next, a cavity (not shown) formed by removing the core 2 is filled with a second fiber reinforced resin, and the core is operated under desired conditions to form a second fiber reinforced resin layer. The core 3 is removed from (step (2)). Then, the above steps (1) and (2) are repeated according to the number of fiber reinforced resin layers to be formed (in the example shown in FIG. 18, since the third fiber reinforced resin layer is formed, another one
Times).

In the manufacturing method of the present invention, as described above, since injection molding using two-color molding is performed, a plurality of fiber-reinforced resin layers are required as compared with a physical winding method such as a sheet winding method or a FW method. Can be laminated with good adhesion, and the productivity can be greatly improved. In addition, since the orientation of the reinforcing fibers can be precisely controlled by the above-described rotation control unit, desired characteristics can be imparted to each fiber-reinforced resin layer. In the above-described manufacturing method, the core is rotated with the mold fixed. However, the present invention is not limited to this, and the mold may be rotated with the core fixed, or both may be rotated. It goes without saying that you can do it.

[0037]

The present invention will be described below in more detail with reference to the drawings by way of examples and comparative examples, but the present invention is not limited to these examples.

(Example 1) The manufacturing method of the present invention was carried out by using the mold shown in FIG. 18, and the energy absorbing member of this example having a laminated tube structure as shown in FIGS. Obtained. In this embodiment, the layer 10 has a tube wall cross section 100
In (R), the orientation angle θ of the glass fiber is −15 ° (hereinafter abbreviated as “GF orientation−15 °”),
A fiber reinforced resin having a matrix of nylon and a glass fiber (GF) content of 40% by weight (hereinafter referred to as “PA66 / GF”).
40 wt% ”), and the layer 20 is made of GF
PA66 / GF50wt% with orientation + 15 °
A three-layer structure in which the layer 20 was sandwiched between two layers 10 was adopted. The fiber length of GF was 12 mm and the fiber diameter was 13 μm. The outer shape is a cylindrical shape having a taper angle α of 45 ° and a constant thickness, and the size is 200 mm in length.
× outer diameter 50 mm × thickness 2.5 mm.

[Evaluation of Performance] The energy absorbing member of this example was statically crushed under the following conditions, and its absorbed energy was measured. The obtained value (kJ) was divided by the weight (kg) of the crushed energy absorbing member. In this way, the specific energy absorption was determined, and the results are shown in Table 1. -Test conditions Apparatus: Digital static material testing machine-5507 (manufactured by Instron) Test speed: 10 mm / min Displacement: 60 mm Test temperature: 23 ° C

(Embodiment 2) The layer 10 is made of PA66 / GF30
wt% (GF orientation -15 °), and the layer 20 is made of PA66 /
The same configuration as in Example 1 was adopted except that GF was 40 wt% (GF orientation + 15 °). FIG. 3 shows the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 1.

(Embodiment 3) The layer 10 is made of PA66 / GF20
wt% (GF orientation -15 °), and the layer 20 is made of PA66 /
The same configuration as in Example 1 was adopted except that GF was 30 wt% (GF orientation + 15 °). FIG. 4 shows the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 1.

Example 4 The same structure as in Example 1 was adopted except that the matrix in the layers 10 and 20 was made of polypropylene (PP). FIG. 5 shows the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 1.

Example 5 The same configuration as in Example 2 was adopted except that the matrix in the layers 10 and 20 was made of polypropylene (PP). FIG. 6 shows the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 1.

(Comparative Example 1) The same configuration as in Example 1 was adopted except that the taper 100t was not formed. FIG.
8 and FIG. 8 show the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 2.

Comparative Example 2 G in Layer 10 and Layer 20
The same configuration as in Example 1 was adopted except that the F orientation was set to 0 °. FIG. 9 shows the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 2.

(Embodiment 6) G in layers 10 and 20
The same configuration as in Example 1 was adopted except that the F orientation was set to -75 ° and + 75 °, respectively. FIG. 10 shows the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 2.

(Example 7) The same configuration as in Example 1 was adopted except that the fiber length of GF was 5 mm. In FIG.
3 shows an energy absorbing member of the present example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 2.

(Comparative Example 5) FW was conducted using continuous fibers containing 49 wt% GF as the matrix resin and epoxy resin.
By performing the method, as shown in FIG. 12, an energy absorbing member of this example having the same shape and dimensions as the energy absorbing member of Example 1 was obtained. Note that the orientation angle of GF is about ± 75 °. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 2.

Comparative Example 6 Injection molding was performed using a fiber reinforced resin (PA66 / GF40 wt%) containing 66-nylon as a matrix resin and containing 50% by weight of GF (fiber length 5 mm), as shown in FIG. An energy absorbing member of the present example having a single-layer structure with a GF orientation of −15 ° and having the same shape and dimensions as the energy absorbing member of Example 1 was obtained.
The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 2.
It was shown to.

Comparative Example 7 Steel Pipe JIS G3
An energy absorbing member (steel pipe) of the present example having the same shape and dimensions as the energy absorbing member of Example 1 was prepared using a steel material conforming to 445. FIG. 17 shows the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 2.

(Example 6) The same configuration as in Example 1 was adopted except that a truncated cone shape with a side surface inclined at 10 ° was applied. 13 and 14 show the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 1.

Example 7 The same configuration as in Example 1 was adopted except that a bottomed shape was applied. However, there is no GF orientation at the bottom. FIG. 15 shows the energy absorbing member of this example. The same performance evaluation as in Example 1 was performed, and the obtained results are shown in Table 1.

[0053]

[Table 1]

[0054]

[Table 2]

From Tables 1 and 2, when Examples 1 to 7 belonging to the scope of the present invention and Comparative Examples 1 to 7 are compared, the following can be understood. The specific energy absorption amount is substantially proportional to the content of the matrix resin constituting the energy absorbing member (Examples 1 to 3). 66-
The case of using nylon has a higher specific energy absorption than the case of polypropylene, and is suitable for use as an energy absorbing member (Examples 4 and 5 for Examples 1 and 2).
5).

When the orientation angle of the reinforcing fibers is controlled within a predetermined range, for example, ± 15 ° with respect to the axial direction, the specific energy absorption increases, as compared with the case where the fiber orientation is ± 0 °. Warping can also be effectively prevented (Comparative Examples 2 and 3 with respect to Example 1). Further, when the impact action portion has a pointed shape, buckling can be effectively prevented (Comparative Example 1 with respect to Example 1). Further, the length of the reinforcing fiber is 10 mm or more, for example, 1
The case of 2 mm is more preferable than the case of 5 mm or less because the specific energy absorption increases (Example 7 with respect to Example 1).

Furthermore, a good energy absorbing ability can be obtained by forming a three-layer structure, and the absorbing member buckles with a one-layer structure (Comparative Example 6 with Example 1). Moreover, in the energy absorbing member obtained by the FW molding method using a continuous fiber of a thermosetting resin (epoxy resin) as a material, the specific energy absorption is significantly reduced (Comparative Example 5 with respect to Example 1).

Further, the energy absorbing member (steel pipe) using a steel material as the material has a very small specific energy absorption as compared with the material made of fiber reinforced resin (Comparative Example 7 with Examples 1 to 7). When the shape is a truncated cone (Example 6) or when the shape is a bottomed one (Example 7).
However, the same specific energy absorption as in Example 1 can be obtained.

[0059]

As described above, according to the present invention, the fiber-reinforced resin layers in which the orientation of the reinforcing fibers is controlled are appropriately laminated, and the whole, particularly, the end portion is formed in a predetermined shape. It is possible to provide an energy absorbing member which achieves good energy absorption performance and is excellent in productivity, a method for producing the same, and a skeleton material for an automobile.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of an energy absorbing member of the present invention.

FIG. 2 is a cross-sectional view of the energy absorbing member of FIG.

FIG. 3 is a sectional view showing another embodiment of the energy absorbing member of the present invention.

FIG. 4 is a sectional view showing another embodiment of the energy absorbing member of the present invention.

FIG. 5 is a sectional view showing another embodiment of the energy absorbing member of the present invention.

FIG. 6 is a sectional view showing another embodiment of the energy absorbing member of the present invention.

FIG. 7 is a perspective view showing an energy absorbing member (Comparative Example 1) outside the present invention.

8 is a cross-sectional view of the energy absorbing member of FIG.

FIG. 9 is a sectional view showing an energy absorbing member (Comparative Example 2) outside the present invention.

FIG. 10 shows an energy absorbing member outside the present invention (Example 6).
FIG.

FIG. 11 is an energy absorbing member outside the present invention (Example 7).
FIG.

FIG. 12 is an energy absorbing member outside the present invention (Comparative Example 5).
FIG.

FIG. 13 is a perspective view showing another embodiment of the energy absorbing member of the present invention.

FIG. 14 is a cross-sectional view of the energy absorbing member of FIG.

FIG. 15 is a sectional view showing another embodiment of the energy absorbing member of the present invention.

FIG. 16 shows an energy absorbing member outside the present invention (Comparative Example 6).
FIG.

FIG. 17 is a perspective view of a steel pipe.

FIG. 18 is a cross-sectional view illustrating an example of a mold used in the manufacturing method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mold 2, 3, 4 cylindrical core 5 mold cavity 6 rotating shaft 7 motor 8 resin inlet 9 rotation control unit 10, 20 fiber reinforced resin layer 100 energy absorbing member 100 t pointed end

Claims (12)

[Claims] 1. A laminated tubular energy absorbing member formed by laminating a plurality of fiber-reinforced resin layers made of a fiber-reinforced resin in which a reinforcing fiber is dispersed in a matrix resin, wherein the reinforcing fibers are aligned with an axis of the laminated tube. An energy absorbing member which is oriented at an arbitrary angle with respect to the stacked tube, wherein the thickness of the tube wall of the laminated tube decreases as approaching one end, and the end has a pointed shape. 2. In a cross section passing through and parallel to the axis of the laminated tube, the one end direction of the axis is defined as 0 °, and the orientation angle between the axis and the reinforcing fibers is defined as the inner side of the laminated tube. When the angle formed on the outer side is indicated by a negative value and the angle formed on the outer side is indicated by a positive value, the orientation angle in one tube wall cross section of the laminated tube is ±.
2. The energy absorbing member according to claim 1, wherein the angle is 10 ° to ± 45 ° and the orientation angle in the other tube wall cross section is − (± 10 ° to ± 45 °). 3. In the adjacent fiber-reinforced resin layer,
The energy absorbing member according to claim 2, wherein the sign of the orientation angle of the reinforcing fiber is reversed. 4. The pointed shape is defined by a taper in which the outer wall thickness of the tube wall is reduced, and the taper angle is 30-7.
4. The method according to claim 1, wherein the angle is 5 °.
An energy absorbing member according to any one of the first to third aspects. 5. The energy absorbing member according to claim 1, wherein the other end of the laminated tube has a bottom. 6. The energy absorbing member according to claim 1, wherein the laminated tube has a substantially frustoconical shape. 7. The energy absorbing member according to claim 1, wherein the reinforcing fiber has a length of 10 mm or more. 8. The matrix resin is polypropylene and / or polyamide, the content of which is 25 to 9.
The energy absorbing member according to any one of claims 1 to 7, wherein the amount is 0% by weight. 9. The method according to claim 1, wherein the reinforcing fibers are glass fibers and / or carbon fibers, and the content thereof is 75 to 10% by weight. Energy absorbing member. 10. A two-layer fiber reinforced resin comprising a polyamide as the matrix resin and three fiber reinforced resin layers in which the reinforcing fibers are glass fibers, and having a glass fiber content of 20 to 30% by weight. The energy absorbing member according to any one of claims 1 to 7, wherein a fiber reinforced resin layer having a glass fiber content of 40 to 50% by weight is inserted between the resin layers. 11. A skeleton material for an automobile, comprising the energy absorbing member according to claim 1. Description: 12. In manufacturing the energy absorbing member according to any one of claims 1 to 10, a core portion having a plurality of concentrically arranged cylindrical cores, and the core portion may be arbitrarily selected. A mold having a rotation control device for rotating at a rotation angle, speed, torque and timing is used. (1) The mold is filled with a first fiber reinforced resin of a plurality of fiber reinforced resins, After operating the portion to form a first fiber reinforced resin layer in which the reinforcing fibers are oriented, the first core provided at the outermost peripheral portion of the plurality of cylindrical cores is removed from the core portion, 2) Next, after filling the second fiber reinforced resin to form a second fiber reinforced resin layer, the second core is removed from the core portion, and (3) the above step (1) or (2) is formed. Repeating according to the number of fiber reinforced resin layers Method for producing the energy absorbing member, wherein.