JP6290641B2 - Resin shock absorber - Google Patents

Description

  The present invention relates to a resin impact absorbing member made of a fiber reinforced resin material containing a reinforced fiber and a thermoplastic resin. More specifically, the present invention relates to a reinforced fiber having a specific average fiber length and a specific breaking elongation. The present invention relates to a resin impact absorbing member made of a fiber reinforced resin material having a specific compressive modulus and compressive strength and having a hollow structure of a specific shape suitable for impact absorption.

  In order to prevent a shock at the time of a collision from being directly transmitted to a person, a shock absorbing member such as a crash box, a front side member, and a rear side member is often provided in front of or behind the vehicle. Conventionally, the shock absorbing member has been generally made of a metal material. However, in recent years, it has been desired to reduce the weight of the vehicle for the purpose of improving the fuel consumption, and research on making the shock absorbing member with a resin has been conducted. It is actively done.

  In a resin shock absorbing member, in order to obtain stable shock absorbing performance, the structure of the shock absorbing member is designed so that the load received by the shock absorbing member with respect to deformation is constant. . For example, Patent Document 1 discloses an impact absorbing member in which a receiving member having a tapered outer cylindrical surface having a taper angle and a cylindrical member are fitted so as to be capable of frictional engagement. Patent Document 2 discloses an impact absorbing member made of fiber reinforced resin that changes a cross-sectional shape in a direction orthogonal to the impact absorbing direction toward the impact absorbing direction. Further, Patent Document 3 discloses an impact absorbing member made of a fiber reinforced resin that has a member thickness on the opposite side larger than a member thickness on the impact input side and projects the tip of the input portion outward from the outer peripheral surface. It is disclosed. However, the impact absorbing members disclosed in each of these patent documents often have a special and complicated structure, which may complicate the manufacturing method or limit the application.

  On the other hand, research for obtaining stable shock absorbing performance is being performed not by optimizing the structure of the shock absorbing member but by optimizing the resin material constituting the shock absorbing member. For example, Patent Document 4 discloses a shock-absorbing member made of fiber-reinforced resin, in which the arrangement density of reinforcing fiber bundles is arranged so as to gradually increase from the input side in the shock absorption direction to the other side. However, also in this case, a special manufacturing method is required, and the manufacturing process may be complicated.

JP 2012-87849 A JP 2005-195155 A JP-A-6-264949 JP 2005-193755 A

  As described above, in order to obtain a stable shock absorbing performance in the resin shock absorbing member, the structure of the shock absorbing member and the resin material constituting the shock absorbing member are complicated, or the manufacturing method of the shock absorbing member is complicated. There is a problem that the use of the shock absorbing member is limited. The present invention has been made in view of such problems, and an object of the present invention is to provide a resin shock absorbing member having a simple structure and stable shock absorbing performance.

In order to solve the above problems, the present invention provides the following means (1) to (5).
(1) A resin-made impact-absorbing member comprising a fiber-reinforced resin material containing reinforcing fibers and a thermoplastic resin, and having a shock-absorbing portion having a hollow structure composed of an outer cylindrical portion and a hollow portion, wherein the reinforcing fibers are The average fiber length is 1 to 100 mm, the thermoplastic resin has a breaking elongation of 10% or more, the fiber reinforced resin material has a compression modulus of 10 GPa or more, and a compression strength of 150 to 500 MPa, The cross-sectional shape in the direction orthogonal to the shock absorbing direction of the shock absorbing portion is a uniform shape over the entire area of the shock absorbing direction, and the shock absorbing portion is located at the center of gravity in the cross-sectional shape in the direction orthogonal to the shock absorbing direction. A resin-made shock absorbing member, wherein a maximum value of a ratio L1 / t1 between the distance L1 from the first cylinder to the outer cylinder portion in the same cross section and the thickness t1 of the outer cylinder portion is 40 or less.
(2) The cross-sectional shape in a direction perpendicular to the shock absorbing direction of the shock absorbing portion is a polygon, and a side length L2 at each side of the polygon and an average thickness t2 of the outer cylinder portion constituting the side The resin impact absorbing member according to (1), wherein the maximum value of the ratio L2 / t2 is 40 or less.
(3) The resin-made impact absorbing member according to (1) or (2), wherein the impact absorbing portion is made of a single fiber-reinforced resin material .
(4) The resin impact absorbing member according to (3), wherein the fiber orientation of the fiber reinforced resin material forming the impact absorbing portion does not change for each portion of the impact absorbing portion .
(5) A vehicle component comprising the resin impact absorbing member according to any one of (1) to (4).

  The resin shock absorbing member of the present invention can exhibit stable shock absorbing performance with a simple structure. Moreover, since the resin impact absorbing member of the present invention has a simple structure, it can be manufactured without using a complicated manufacturing process. Furthermore, the resin impact absorbing member of the present invention can be used for various applications.

It is the schematic which shows an example (perfect circular shape) of the impact-absorbing part in the resin-made impact-absorbing member of this invention. It is the schematic which shows an example (elliptical type) of the impact-absorbing part in the resin-made impact-absorbing members of this invention. It is the schematic which shows an example (square shape) of the impact-absorbing part in the resin-made impact-absorbing member of this invention. It is the schematic which shows an example (hexagonal shape) of the impact-absorbing part in the resin-made impact-absorbing member of this invention. It is the schematic which shows an example (circle + polygon composite type) of the impact-absorbing part in the resin-made impact-absorbing members of this invention. It is the schematic which shows an example (hexagonal shape with a flange) of the impact-absorbing part in the resin-made impact-absorbing members of this invention. It is the schematic which shows sectional drawing (explanation of L1, t1) of the direction orthogonal to the shock absorption direction of the shock absorption part illustrated in FIG. It is the schematic which shows sectional drawing (explanation of L2, t2) of the direction orthogonal to the shock absorption direction of the shock absorption part illustrated in FIG. 3 is a schematic view of an impact absorbing portion in the resin impact absorbing member of Example 1. FIG. It is the schematic of the impact-absorbing part in the resin-made impact-absorbing members of Example 2. 6 is a schematic view of an impact absorbing portion in a resin impact absorbing member of Example 3. FIG. It is a conceptual diagram (example of unstable shock absorption) of an impact load F-displacement S curve. It is a conceptual diagram (example of stable shock absorption) of an impact load F-displacement S curve.

  The resin impact absorbing member of the present invention is made of a fiber reinforced resin material containing reinforcing fibers and a thermoplastic resin, and has a hollow impact absorbing portion composed of an outer tube portion and a hollow portion, Reinforcing fibers have an average fiber length of 1 to 100 mm, the thermoplastic resin has a breaking elongation of 10% or more, the fiber reinforced resin material has a compressive elastic modulus of 10 GPa or more, and a compressive strength of 150 to 500 MPa. The shock absorbing portion is the maximum value of the ratio L1 / t1 between the distance L1 from the position of the center of gravity in the cross-sectional shape perpendicular to the shock absorbing direction to the outer cylindrical portion in the same cross section, and the thickness t1 of the outer cylindrical portion. Is 40 or less.

  The resin impact absorbing member of the present invention is used for suppressing impact to the other end side by absorbing impact energy input to one end of the resin impact absorbing member by the impact absorbing portion. . Further, the resin shock absorbing member of the present invention assumes so-called shock absorption in the axial compression direction, and is used to absorb the shock received in the coaxial direction with the penetration direction of the hollow structure of the shock absorbing portion. is there. Hereinafter, this “direction in which the shock absorbing portion penetrates the hollow structure and the coaxial direction” is referred to as “shock absorbing direction”.

  The impact energy input from one end of the resin shock absorbing member of the present invention is absorbed by the shock absorbing portion, and the shock absorbing mechanism utilizes the crushing phenomenon of the shock absorbing portion in the shock absorbing direction. That is, normally, when an impact is applied to the impact absorbing portion, as illustrated in FIG. 12, a displacement S occurs due to the crushing phenomenon while absorbing the impact load F, and the area surrounded by the impact load F-displacement S curve. Is the amount of impact energy absorbed. The crushing phenomenon is composed of a compressive fracture in the direction of shock absorption and a buckling phenomenon that accompanies it, but due to the buckling phenomenon, the load applied after the initial impact load is higher than the initial impact load as shown in FIG. Therefore, the displacement becomes large in order to achieve the desired shock absorption. When the displacement increases, it is not preferable because the impact absorbing portion needs to be increased accordingly. Further, if the impact load at the time of absorbing the impact is large, the impact received by the personnel at the time of the collision is not preferable. Therefore, as illustrated in FIG. 13, it is preferable that the impact absorbing portion is designed so that the impact load is constant with respect to the displacement so that the maximum impact load and the displacement are reduced.

The “stable shock absorbing performance” in the present invention indicates the phenomenon illustrated in FIG. 13, and the present invention is stable with a simple structure without making the shock absorbing portion complicated. It is a main object of the present invention to provide a resin-made shock absorbing member that exhibits the shock absorbing performance.
In order to obtain the stable shock absorbing performance as described above, it is necessary to reduce the pitch of the buckling phenomenon that occurs during the crushing phenomenon (hereinafter referred to as “buckling pitch”). When the buckling pitch is large, the impact load is drastically reduced with buckling, so that the displacement required to absorb the desired amount of impact energy increases. Therefore, in order to obtain a stable shock absorbing performance, it is necessary to design such that a small buckling pitch is repeated and a sudden drop in impact load does not occur. The resin impact absorbing member of the present invention is made of the above-mentioned specific fiber reinforced resin material, and by using an impact absorbing portion having a specific hollow structure, it is possible to reduce the buckling pitch and thereby stabilize it. To achieve the shock absorbing performance.

[Shock absorber]
The impact absorbing portion in the present invention is made of a fiber reinforced resin material containing reinforced fibers and a thermoplastic resin, and has a hollow structure consisting of an outer cylinder portion and a hollow portion, and has a direction perpendicular to the impact absorbing direction. The maximum value of the ratio L1 / t1 between the distance L1 from the position of the center of gravity in the cross-sectional shape to the outer cylinder part in the same cross section and the thickness t1 of the outer cylinder part is 40 or less. Here, the said hollow part refers to the space in the said outer cylinder part. Moreover, the impact-absorbing part used in the present invention has an average fiber length of the reinforcing fibers of 1 to 100 mm, a breaking elongation of the thermoplastic resin of 10% or more, and a compression elastic modulus of the fiber-reinforced resin material. Is 10 GPa or more and the compressive strength is 150 to 500 MPa. Hereinafter, the impact absorbing portion used in the present invention will be described. The fiber reinforced resin material used for the impact absorbing portion will be described later.

  The shock absorber used in the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a typical example of an impact absorbing portion 1 constituting the resin impact absorbing member of the present invention. As illustrated in FIG. 1, the impact absorbing portion 1 used in the present invention includes an outer cylindrical portion 2 and a hollow portion 3. A dotted arrow X in FIG. 1 indicates the shock absorption direction of the shock absorber 1.

  In FIG. 1, as an example of the shock absorbing portion in the present invention, an example in which the cross-sectional shape perpendicular to the shock absorbing direction is a true circular shape is shown, but the shock absorbing portion in the present invention has such a shape. However, the cross-sectional shape can be any shape. Therefore, for example, the cross-sectional shape may be an elliptical shape (for example, FIG. 2), a quadrangular shape (for example, FIG. 3), or a polygon such as a hexagon (for example, FIG. 4), or the cross-sectional shape. The shape (for example, FIG. 5) which combined circular type and polygon type may be sufficient. Further, the impact absorbing portion in the present invention may be a combination of a hat type having a flange portion as illustrated in FIG. 2 to 6 are the same as those in FIG.

  The shock absorbing portion constituting the resin shock absorbing member of the present invention has a distance L1 from the position of the center of gravity in the cross-sectional shape perpendicular to the shock absorbing direction to the outer cylindrical portion in the same cross section, and the thickness t1 of the outer cylindrical portion. The maximum value of the ratio L1 / t1 is 40 or less. This point will be described with reference to the drawings. FIG. 7 illustrates the impact absorbing portion illustrated in FIG. 6 as an example, the “distance L1 from the position of the center of gravity to the outer cylindrical portion in the same cross section” in the cross-sectional shape perpendicular to the shock absorbing direction, and the “outer cylinder” It is explanatory drawing explaining the thickness t1 of a part. As illustrated in FIG. 7, the “thickness t1 of the outer cylinder portion” is the thickness of the outer cylinder portion at an arbitrary point 5 in an arbitrary cross section 4 orthogonal to the shock absorption direction. The “distance L1 from the position of the center of gravity to the outer cylinder portion in the same cross section” is a distance from the position of the center of gravity 6 in an arbitrary cross section 4 to an arbitrary point 5. Arbitrary point 5 is an intermediate point in the thickness direction.

  The L1 / t1 is a value obtained by dividing the “distance L1 from the position of the center of gravity to the outer cylinder part in the same cross section” by the “thickness t1 of the outer cylinder part”, and L1 and t1 are the same unit system. This L1 / t1 is a value indicating the shape rigidity of the impact absorbing portion, and the smaller the value, the greater the shape rigidity against the compression load. The shock absorbing portion in the present invention is characterized in that the maximum value of L1 / t1 is 40 or less. When the maximum value of L1 / t1 exceeds 40, the shape rigidity of the impact absorbing portion is reduced, and the buckling pitch is increased, so that the impact load is rapidly reduced. A more preferable range of the maximum value of L1 / t1 is 30 or less, and a more preferable range is 20 or less. Here, the maximum value of L1 / t1 is the largest value among the values of L1 / t1 calculated for each point in the outer cylinder part in the arbitrary cross section in the direction orthogonal to the shock absorbing direction of the shock absorbing part in the present invention. It is. In the case where the cross-sectional shape changes over the entire region or part of the shock absorption direction, the maximum value of L1 / t1 is calculated for each cross-section, and the maximum value is set as the maximum value of L1 / t1.

  In addition, each value of said L1 and t1 will not be specifically limited if it is in the range which can make the maximum value of said L1 / t1 into 40 or less, According to the use etc. of the resin-made impact-absorbing members of this invention, it is appropriate. Can be adjusted.

  The shock absorbing portion constituting the resin shock absorbing member of the present invention has a polygonal cross-sectional shape in a direction orthogonal to the shock absorbing direction, and the side length L2 on each side of the polygon and the side constituting the side. The maximum value of the ratio L2 / t2 with respect to the average thickness t2 of the outer tube portion is preferably 40 or less. As described above, the cross-sectional shape of the impact absorbing portion of the present invention is not particularly limited, and may be either a circular shape or a polygonal shape. For example, a vehicle impact absorbing member is joined to a peripheral component. In many cases, it is a polygonal shape from the viewpoints of performance and arrangement. In addition, a polygonal shock absorbing member having a large number of corners tends to have a buckling pitch smaller than that of a circular type, and the sectional shape of the shock absorbing portion of the present invention is also a polygonal shape from the viewpoint of shock absorbing performance. Furthermore, it is preferable that the polygonal shape has a large number of corners. In the case of the polygonal type, the ratio L2 between the side length L2 at each side and the average thickness t2 of the outer cylinder part constituting the side of the polygonal cross section in the direction orthogonal to the shock absorbing direction of the shock absorbing part of the present invention. The maximum value of / t2 is preferably 40 or less.

  This point will be described with reference to the drawings. FIG. 8 shows, as an example, the impact absorbing portion illustrated in FIG. 6, the “side length L2 at each side” in the cross-sectional shape perpendicular to the shock absorbing direction, and the “average of the outer cylinder portions constituting the side” It is explanatory drawing explaining "thickness t2." As illustrated in FIG. 8, the “side length L <b> 2 at each side” is the length of the arbitrary side 7 of the outer cylinder portion in the arbitrary cross section 4 orthogonal to the shock absorption direction. The “average thickness t2 of the outer cylinder part constituting the side” is an average thickness of the outer cylinder part constituting the arbitrary side 7.

  The L2 / t2 is a value obtained by dividing the “side length L2 at each side” by the “average thickness t2 of the outer cylinder portion constituting the side”, and L2 and t2 are the same unit system. Note that the side length L2 in the case where the end point of the side is a curved portion is the side length when the end point is a point that intersects with an adjacent side when it is assumed that there is no curved portion. The maximum value of L2 / t2 is the largest value among the values of L2 / t2 calculated for each side in the outer cylinder portion of an arbitrary cross section. When the cross-sectional shape changes in the direction of shock absorption, the maximum value of L2 / t2 is calculated for each cross-section, and the maximum value is set as the maximum value of L2 / t2. L2 / t2 is a value indicating the shape rigidity of the surface constituting the outer cylinder portion of the polygonal impact absorbing portion, and the smaller the value, the greater the shape rigidity. The maximum value of L2 / t2 in the present invention is preferably 40 or less. When the maximum value of L2 / t2 exceeds 40, the shape rigidity of the surface constituting the outer cylindrical portion of the polygonal impact absorbing portion is reduced, and the buckling pitch is increased. This is because it may end up. A more preferable range of the maximum value of L2 / t2 is 35 or less, and a more preferable range is 30 or less.

  The values of L2 and t2 are not particularly limited as long as the maximum value of L2 / t2 of the shock absorbing portion is 40 or less, and the value of the resin shock absorbing member of the present invention is not particularly limited. It can adjust suitably according to a use etc.

  The impact absorbing portion constituting the resin impact absorbing member of the present invention preferably has a uniform cross-sectional shape in the direction orthogonal to the impact absorbing direction over the entire area of the impact absorbing direction. In addition, the cross-sectional shape is “uniform throughout the shock absorbing direction” means that the cross-sectional shape of the shock absorbing portion in the direction perpendicular to the shock absorbing direction is the same. In order to obtain stable shock absorbing performance, the thickness of the outer cylinder part is also changed across the shock absorption direction as in Patent Document 3, but when changing the thickness of the outer cylinder part, the resin material is made of gold. There may be a problem that the process of arranging the mold becomes complicated. The shock absorbing part used in the present invention has a stable shock absorbing performance by the above-mentioned means even if the cross-sectional shape in the direction perpendicular to the shock absorbing direction of the shock absorbing part is uniform in the shock absorbing direction. Can be obtained.

  The impact absorbing portion constituting the resin impact absorbing portion of the present invention is preferably made of a single fiber reinforced resin material. The term “single fiber reinforced resin material” as used herein refers to the location of the shock absorbing portion even if a plurality of types of fiber reinforced resin materials are used, or even if one type of fiber reinforced resin material is used. It means that it is made of any kind of fiber reinforced resin material without intentionally changing every time, and the fiber orientation is not intentionally changed for each part of the shock absorbing portion. In order to obtain stable shock absorbing performance, even if multiple types of fiber reinforced resin materials are used, or even if one type of fiber reinforced resin material is used, the fiber orientation is intentionally different for each part of the shock absorbing portion. However, there are cases where the manufacturing process becomes complicated, and the compressive strength and buckling resistance strength of the boundary portion of the material become weak. The resin impact absorbing member of the present invention can obtain stable impact absorbing performance by the above-described means even if the impact absorbing portion is made of a single fiber reinforced resin material.

  The impact absorbing portion in the present invention may have the same or different cross-sectional shape of the outer cylindrical portion over the entire region of the shock absorbing direction, but the resin impact absorbing member of the present invention is the same by being the same. There is an advantage that the manufacturing process can be simplified. In addition, as an aspect in which the cross-sectional shape is different in the shock absorbing direction, for example, a mode in which the cross-sectional shape is continuously changed in the shock absorbing direction or a reinforcing rib or the like is installed in the shock absorbing portion is exemplified. I can. As described above, when the cross-sectional shape is changed, it is desirable that the manufacturing process is not complicated.

  In addition, about the specific magnitude | size of an impact-absorbing part, such as the height of an impact-absorbing part in this invention, a width | variety, and the cross-sectional area of a hollow part, if the said L1 / t1 is a range which can be in the said range, especially. It is not limited and can be determined as appropriate according to the use of the resin impact absorbing member of the present invention.

[Fiber-reinforced resin material]
Next, the fiber reinforced resin material used in the present invention will be described. The fiber reinforced resin material used in the present invention contains at least a reinforced fiber and a thermoplastic resin in order to obtain a desired impact absorbing performance. More specifically, the fiber reinforced resin used in the present invention. The material contains reinforcing fiber and thermoplastic resin, the reinforcing fiber has an average fiber length of 1 to 100 mm, the thermoplastic resin has a breaking elongation of 10% or more, and the fiber reinforced resin. The material is characterized by having a compressive elastic modulus of 10 GPa or more and a compressive strength of 150 to 500 MPa.

(Reinforced fiber)
The type of the reinforcing fiber can be appropriately selected according to the type of the thermoplastic resin and the degree of the impact absorbing property imparted to the impact absorbing portion, and is not particularly limited. For this reason, any of inorganic fibers or organic fibers can be suitably used as the reinforcing fibers used in the present invention.

  Examples of the inorganic fibers include carbon fibers, activated carbon fibers, graphite fibers, glass fibers, tungsten carbide fibers, silicon carbide fibers (silicon carbide fibers), ceramic fibers, alumina fibers, natural fibers, mineral fibers such as basalt, and boron fibers. , Boron nitride fiber, boron carbide fiber, and metal fiber. Examples of the metal fiber include aluminum fiber, copper fiber, brass fiber, stainless steel fiber, and steel fiber. As said glass fiber, what consists of E glass, C glass, S glass, D glass, T glass, quartz glass fiber, borosilicate glass fiber, etc. can be mentioned.

  Examples of the organic fibers include fibers made of resin materials such as polybenzazole, aramid, PBO (polyparaphenylene benzoxazole), polyphenylene sulfide, polyester, acrylic, polyamide, polyolefin, polyvinyl alcohol, and polyarylate. it can.

  The reinforcing fiber used in the present invention may be one type or two or more types. In the present invention, when two or more types of reinforcing fibers are used, a plurality of types of inorganic fibers may be used in combination, a plurality of types of organic fibers may be used in combination, or inorganic fibers and organic fibers may be used in combination. . As an aspect which uses multiple types of inorganic fiber together, the aspect which uses together a carbon fiber and a metal fiber, the aspect which uses a carbon fiber and glass fiber together, etc. can be mentioned, for example. On the other hand, examples of the mode in which a plurality of types of organic fibers are used in combination include a mode in which aramid fibers and fibers made of other organic materials are used in combination. Furthermore, as an aspect using together an inorganic fiber and an organic fiber, the aspect which uses together a carbon fiber and an aramid fiber can be mentioned, for example.

  In the present invention, it is preferable to use carbon fibers as the reinforcing fibers. This is because carbon fibers can provide a fiber-reinforced resin material that is lightweight but excellent in strength. The carbon fibers are generally polyacrylonitrile (PAN) based carbon fibers, petroleum / coal pitch based carbon fibers, rayon based carbon fibers, cellulosic carbon fibers, lignin based carbon fibers, phenol based carbon fibers, and vapor growth systems. Although carbon fiber etc. are known, in the present invention, any of these carbon fibers can be suitably used.

  The reinforcing fiber used in the present invention may have a sizing agent attached to the surface. When using the reinforcing fiber to which the sizing agent is attached, the type of the sizing agent can be appropriately selected according to the types of the reinforcing fiber and the thermoplastic resin, and is not particularly limited.

  The average fiber length of the reinforcing fiber used in the present invention is 1 to 100 mm. When the average fiber length is less than 1 mm, the compressive strength of the fiber reinforced resin material may be insufficient below the desired range, and the displacement of the impact absorbing portion at the time of impact absorption may be increased. In addition, when the average fiber length exceeds 100 mm, the compressive strength of the fiber reinforced resin material becomes too larger than the desired range, the initial impact load becomes large, or the fiber length is too long. It may become too large and cause a sudden drop in impact load. The average fiber length of the reinforcing fibers used in the present invention is not particularly limited as long as it is within the above range, but a more preferable range is 5 to 75 mm, and a further preferable range is 10 to 50 mm. Here, the average fiber length (La) of the reinforcing fibers is measured, for example, by measuring the fiber length (Li) of 100 fibers randomly extracted from the fiber reinforced resin material to the 1 mm unit using a caliper or the like. It can be determined based on the formula. Extraction of reinforcing fibers from the fiber reinforced resin material can be performed, for example, by subjecting the fiber reinforced resin material to a heat treatment of about 500 ° C. × 1 hour and removing the resin in a furnace. La = ΣLi / 100

  The average fiber diameter of the reinforcing fibers used in the present invention may be appropriately determined according to the type of reinforcing fibers and the like, and is not particularly limited. For example, when carbon fiber is used as the reinforcing fiber, the average fiber diameter is usually preferably in the range of 3 μm to 50 μm, more preferably in the range of 4 μm to 12 μm, and in the range of 5 μm to 8 μm. More preferably. On the other hand, when glass fiber is used as the reinforcing fiber, the average fiber diameter is usually preferably in the range of 3 μm to 30 μm. Here, the said average fiber diameter shall point out the diameter of the single yarn of a reinforced fiber. Therefore, when the reinforcing fiber is in the form of a fiber bundle, it refers to the diameter of the reinforcing fiber (single yarn) constituting the fiber bundle, not the diameter of the fiber bundle. The average fiber diameter of the reinforcing fibers can be measured by a method described in JIS R7607, for example.

  Regardless of the type, the reinforcing fiber used in the present invention may be a single yarn consisting of a single yarn, or may be a fiber bundle consisting of a plurality of single yarns. In addition, the reinforcing fiber used in the present invention may be only a single yarn, may be a fiber bundle, or a mixture of both. When a fiber bundle is used, the number of single yarns constituting each fiber bundle may be substantially uniform or different in each fiber bundle. When the reinforcing fibers used in the present invention are in the form of fiber bundles, the number of single yarns constituting each fiber bundle is not particularly limited, but is usually in the range of 1000 to 100,000.

  Generally, carbon fibers are in the form of fiber bundles in which thousands to tens of thousands of filaments are gathered. When carbon fibers are used as the reinforcing fibers, if the carbon fibers are used as they are, the entangled portions of the fiber bundles are locally thick and it may be difficult to obtain a thin fiber reinforced material. For this reason, when carbon fiber is used as the reinforcing fiber, the fiber bundle is usually used after being widened or opened.

When the carbon fiber bundle is opened and used, the opening degree of the carbon fiber bundle after opening is not particularly limited, but the opening degree of the fiber bundle is controlled, and the carbon fiber bundle consists of a specific number or more of carbon fibers. It is preferable to include a carbon fiber bundle and a carbon fiber (single yarn) or a carbon fiber bundle less than that. In this case, specifically, the carbon fiber bundle (A) constituted by the number of critical single yarns or more defined by the following formula (1) and the other opened carbon fibers, that is, the state of the single yarn or the criticality It is preferably composed of a fiber bundle composed of less than the number of single yarns.
Critical number of single yarns = 600 / D (1)
(Where D is the average fiber diameter (μm) of the carbon fiber)

  Furthermore, in the present invention, the ratio of the carbon fiber bundle (A) to the total amount of carbon fibers in the fiber reinforced resin material is preferably more than 0 Vol% and less than 99 Vol%, more preferably 20 Vol% or more and less than 99 Vol, More preferably, it is 30 Vol% or more and less than 95 Vol%, Most preferably, it is 50 Vol% or more and less than 90 Vol%. Thus, the abundance of carbon fibers in the fiber-reinforced resin material by coexisting carbon fiber bundles composed of carbon fibers of a specific number or more and other opened carbon fibers or carbon fiber bundles in a specific ratio. That is, the fiber volume content (Vf) can be increased.

  The degree of opening of the carbon fiber can be set within a target range by adjusting the opening condition of the fiber bundle. For example, when the fiber bundle is opened by blowing air onto the fiber bundle, the degree of opening can be adjusted by controlling the pressure of the air blown onto the fiber bundle. In this case, by increasing the air pressure, the degree of opening is increased (the number of single yarns constituting each fiber bundle is small), and by reducing the air pressure, the degree of opening is reduced (constituting each fiber bundle). The number of single yarns to be increased).

When carbon fiber is used as the reinforcing fiber in the present invention, the average number of fibers (N) in the carbon fiber bundle (A) can be appropriately determined within a range not impairing the object of the present invention, and is particularly limited. It is not a thing. In the case of carbon fiber, the N is usually within the range of 1 <N <12000, but more preferably satisfies the following formula (2).
0.6 × 10 ⁴ / D ² <N <1 × 10 ⁵ / D ² (2)
(Where D is the average fiber diameter (μm) of the carbon fiber)

(Thermoplastic resin)
Next, the thermoplastic resin used in the present invention will be described. The breaking elongation of the thermoplastic resin used in the present invention is 10% or more. The shock absorbing portion constituting the shock absorbing member of the present invention can obtain stable shock absorbing performance by being crushed by a small buckling pitch, but the heat in the fiber reinforced resin material constituting the shock absorbing portion can be obtained. When the fracture elongation of the plastic resin is less than 10%, the impact absorbing portion collapses into a brittle failure mode, and the collapse becomes unstable or the buckling pitch becomes large. There is a possibility that a sudden drop will occur. A more preferable range of the breaking elongation of the thermoplastic resin used in the present invention is 30% or more, and a more preferable range is 50% or more. The breaking elongation of a thermoplastic resin is a breaking elongation at the time of a tensile test, and can be measured by, for example, a method described in JIS K7162.

The thermoplastic resin used in the present invention is not particularly limited as long as the fracture elongation is within the above-described range. As the thermoplastic resin used in the present invention, one having a softening point in the range of 180 ° C. to 350 ° C. is usually used, but is not limited thereto.
Examples of the thermoplastic resin used in the present invention include polyolefin resin, polystyrene resin, thermoplastic polyamide resin, polyester resin, polyacetal resin (polyoxymethylene resin), polycarbonate resin, (meth) acrylic resin, polyarylate resin, polyphenylene. Examples include ether resins, polyimide resins, polyether nitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyether ketone resins, thermoplastic urethane resins, fluorine resins, and thermoplastic polybenzimidazole resins. .

Examples of the polyolefin resin include polyethylene resin, polypropylene resin, polybutadiene resin, polymethylpentene resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, and polyvinyl alcohol resin.
Examples of the polystyrene resin include polystyrene resin, acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin), and the like. Examples of the polyamide resin include polyamide 6 resin (nylon 6), polyamide 11 resin (nylon 11), polyamide 12 resin (nylon 12), polyamide 46 resin (nylon 46), polyamide 66 resin (nylon 66), and polyamide 610. Resin (nylon 610) etc. can be mentioned. Examples of the polyester resin include polyethylene terephthalate resin, polyethylene naphthalate resin, boribylene terephthalate resin, polytrimethylene terephthalate resin, and liquid crystal polyester. Examples of the (meth) acrylic resin include polymethyl methacrylate. Examples of the modified polyphenylene ether resin include modified polyphenylene ether. Examples of the thermoplastic polyimide resin include thermoplastic polyimide, polyamideimide resin, polyetherimide resin, and the like. Examples of the polysulfone resin include a modified polysulfone resin and a polyethersulfone resin. Examples of the polyetherketone resin include polyetherketone resin, polyetheretherketone resin, and polyetherketoneketone resin. As said fluororesin, polytetrafluoroethylene etc. can be mentioned, for example.

  The thermoplastic resin used in the present invention may be only one type or two or more types. Examples of modes in which two or more types of thermoplastic resins are used in combination include modes in which thermoplastic resins having different softening points or melting points are used in combination, modes in which thermoplastic resins having different average molecular weights are used in combination, and the like. However, this is not the case.

(Fiber reinforced resin material)
The fiber reinforced resin material used in the present invention is characterized in that the compression elastic modulus is 10 GPa or more. When the compression elastic modulus of the fiber reinforced resin material is less than 10 GPa, the shape rigidity of the outer cylinder part constituting the shock absorbing part is insufficient, and the buckling pitch becomes large, which may cause a sudden drop in the impact load. . A more preferable range of the compression modulus is 15 GPa or more, and a more preferable range is 20 GPa or more. In order to make the compression elastic modulus of the fiber reinforced resin material used in the present invention within the above range, for example, the content of the reinforced fiber in the fiber reinforced resin material is adjusted, the fiber length is adjusted, or the reinforcement is This is achieved by a method such as changing the type of fiber or / and thermoplastic resin. More specifically, the compression elastic modulus can be increased by increasing the content of the reinforcing fiber, increasing the fiber length, and using a reinforcing fiber or / and a thermoplastic resin having a higher compression elastic modulus. . Further, if the adjustment is reversed, the compression elastic modulus can be reduced.

  The fiber reinforced resin material used in the present invention is characterized in that the compressive strength is 150 to 500 MPa. When the compressive strength of the fiber reinforced resin material is less than 150 MPa, the displacement required to absorb the desired impact energy may increase. On the other hand, when the compressive strength exceeds 500 MPa, the initial impact load may become too large. A more preferable range of the compressive strength is 200 to 450 MPa, and a further preferable range is 250 to 400 MPa. In order to set the compression elastic strength of the fiber reinforced resin material used in the present invention within the above range, for example, the content of the reinforced fiber in the fiber reinforced resin material is adjusted, the fiber length is adjusted, or the reinforcement is strengthened. This is achieved by a method such as changing the type of fiber or / and thermoplastic resin. More specifically, the compressive strength can be increased by increasing the content of reinforcing fibers, increasing the fiber length, and using reinforcing fibers and / or thermoplastic resins having a higher compressive strength. Further, the compression strength can be reduced by adjusting the opposite of these.

In addition, the compression elastic modulus and compression strength of a fiber reinforced resin material can be measured by the method described in JIS K7076, for example.
As described above, the fiber reinforced resin material used in the present invention contains at least reinforcing fibers and a thermoplastic resin. However, if it is within the range not impairing the object of the present invention, various additives are included as necessary. But you can. The various additives are not particularly limited as long as they can impart a desired function or property to the fiber reinforced resin material according to the use of the fiber reinforced resin material. Various additives used in the present invention include, for example, melt viscosity reducing agents, antistatic agents, pigments, softeners, plasticizers, surfactants, conductive particles, fillers, carbon black, coupling agents, foaming agents, Lubricants, corrosion inhibitors, crystal nucleating agents, crystallization accelerators, mold release agents, stabilizers, UV absorbers, colorants, colorants, antioxidants, flame retardants, flame retardants, anti-dripping agents, lubricants , Fluorescent whitening agents, phosphorescent pigments, fluorescent dyes, flow modifiers, inorganic and organic antibacterial agents, insecticides, photocatalytic antifouling agents, infrared absorbers, photochromic agents and the like.

The abundance of the thermoplastic resin in the fiber reinforced resin material used in the present invention can be appropriately determined according to the type of the thermoplastic resin, the type of the reinforced fiber, etc., and is not particularly limited. However, it is usually within a range of 3 parts by mass to 1000 parts by mass with respect to 100 parts by mass of the reinforcing fibers.
The volume content of the reinforcing fiber in the fiber reinforced resin material used in the present invention is preferably 10 to 70 Vol%. When the volume content of the reinforcing fiber in the fiber reinforced resin material is less than 10 Vol%, a desired compression elastic modulus or compressive strength may not be obtained. On the other hand, when it exceeds 70 Vol%, the compressive strength becomes too high, or the fluidity of the fiber reinforced resin material is lowered, and a desired shape may not be obtained at the time of molding. A more preferable range of the volume content of the reinforcing fiber in the fiber reinforced resin material is 20 to 60 Vol%, and a more preferable range is 30 to 50 Vol%.

  Moreover, the presence state of the reinforced fiber in the fiber reinforced resin material is not particularly limited, and may be, for example, a state of being arranged in one direction or a state of being randomly arranged. Among them, in the present invention, from the viewpoint of uniformity of shape rigidity and strength in the resin shock absorbing member, a two-dimensional random array in which the long axis direction of the reinforcing fiber is randomly arranged in the in-plane direction of the fiber reinforced resin material. The state is preferable. Here, the two-dimensional random arrangement of the carbon fibers in the fiber reinforced resin material is measured, for example, by performing a tensile test based on an arbitrary direction of the fiber reinforced resin material and a direction perpendicular thereto. Thereafter, it can be confirmed by measuring a ratio (Eδ) obtained by dividing a larger value of the measured tensile modulus by a smaller value. When the elastic modulus ratio is less than 2, it can be evaluated that the carbon fibers are two-dimensional randomly arranged, and when the elastic modulus ratio is less than 1.3, it is evaluated as an excellent two-dimensional random array. .

(Method for producing fiber-reinforced resin material)
Next, the manufacturing method of the fiber reinforced resin material used for this invention is demonstrated. The fiber reinforced resin material used in the present invention can be generally produced using a known method. For example: 1. a step of cutting the reinforcing fiber; 2. opening the cut reinforcing fiber; Although it can manufacture by the process which heat-compresses after mixing the reinforced fiber and fiber-like or particle-shaped thermoplastic resin which were opened, and obtains a prepreg, it is not this limitation. In this method, the prepreg is a fiber reinforced resin material.

[Configuration other than shock absorber]
As described above, the resin shock absorbing member of the present invention has at least the shock absorbing portion, but has a configuration other than the shock absorbing portion as long as the object of the present invention is not impaired. Also good. Other configurations used in the present invention can be appropriately selected within a range that does not impair the purpose of the present invention, depending on the use of the resin impact absorbing member of the present invention, and are not particularly limited. For example, there may be mentioned a flange part for connecting with peripheral parts, a part for reinforcing a resin shock absorbing member, and the like.

  Moreover, the other structure used for this invention may consist of resin materials, or may consist of metal materials, such as iron and aluminum. When the other configuration is made of a resin material, for example, the other configuration may be press-molded as an integral part with the shock absorbing portion, and as a separate component from the shock absorbing portion, welding or bonding to the shock absorbing portion, You may join by methods, such as riveting. On the other hand, when the other configuration is made of a metal material, it is usually joined to the impact absorbing portion by a method such as insert molding, adhesion, or screwing.

[Method for manufacturing resin-made impact absorbing portion]
Next, a method for producing the resin impact absorbing member of the present invention will be described. The resin shock absorbing member of the present invention can be obtained by manufacturing the above-described shock absorbing portion. The impact-absorbing part in the present invention can be produced using a generally known method. For example, the thermoplastic resin constituting the reinforced fiber resin material is preliminarily heated to a temperature equal to or higher than the softening point. A method of cold pressing with a mold having a temperature lower than the softening point of the resin can be applied. In addition, a hot press method in which the reinforced fiber resin material is cooled by cooling to a temperature lower than the softening point of the thermoplastic resin after being put into a mold having a temperature equal to or higher than the softening point of the thermoplastic resin can be applied. This is not the case.

[Uses of resin shock absorbing members]
The resin shock absorbing member of the present invention is a resin shock absorbing member having a hollow shock absorbing portion composed of an outer cylinder portion and a hollow portion, and shock energy input to one end of the resin shock absorbing member is shocked. It is used in order to suppress the impact to the other end side by absorbing with an absorption part. The resin shock absorbing member of the present invention assumes shock absorption in the so-called axial compression direction, and is for shock received in a direction coaxial with the penetration direction of the hollow structure of the shock absorbing portion. Moreover, the resin shock absorbing member of the present invention can be applied to various vehicle parts because of its simple structure.

[Vehicle parts]
The vehicle component of the present invention is composed of the above-described resin-made impact absorbing member of the present invention. The vehicle component of the present invention is not particularly limited as long as the resin shock absorbing member of the present invention is used. For example, a crash box, a front side member, a rear side member, a front wheel house Examples include an upper member and a lower member.

  Further, since the vehicle component of the present invention only needs to use the above-described resin impact absorbing member of the present invention, for example, the vehicle component may consist only of the resin impact absorbing member of the present invention. Alternatively, the resin impact absorbing member of the present invention may be combined with other parts. In addition, the said other components are suitably determined according to the use of the vehicle components of this invention, and are not specifically limited. Moreover, what is necessary is just to determine suitably according to the use of the vehicle components of this invention also about the material which comprises the said other components, and arbitrary resin materials or arbitrary metal materials can be used.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the technical idea described in the claims of the present invention has substantially the same configuration and exhibits the same function and effect regardless of the mode. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be described more specifically by showing examples. However, the present invention is not limited to the embodiments described below.

Each value in this example was determined according to the following method.
(1) Average fiber length of reinforcing fibers The average fiber length of reinforcing fibers in the fiber-reinforced resin material is determined after heating the fiber-reinforced resin material in a furnace at 500 ° C. for 1 hour to remove the thermoplastic resin. The length of 100 reinforcing fibers extracted for purpose was measured to the 1 mm unit with calipers, and the average value was obtained. When the average fiber length was less than 1 mm, it was measured up to 0.1 mm under an optical microscope. When measuring the average fiber length of the reinforcing fibers in the thermosetting fiber reinforced resin material, the fiber reinforced resin material is heated in a furnace at 500 ° C. for 3 hours to remove the thermosetting resin. Measured in the same manner.
(2) Volume content of reinforcing fiber in fiber reinforced resin material The volume content of reinforcing fiber in fiber reinforced resin material is obtained by obtaining the density of fiber reinforced resin material by an underwater substitution method, and the density of reinforcing fiber alone measured in advance. The volume content of the reinforcing fiber was calculated from the relationship between the density of the resin and the resin alone.
(3) Compressive elastic modulus and compressive strength of fiber reinforced resin material The compressive elastic modulus and compressive strength of the fiber reinforced resin material were measured in accordance with JIS K7076 after a test piece was dried in advance at 80 ° C. under vacuum for 24 hours. .
(4) Fracture elongation of thermoplastic resin The fracture elongation of the thermoplastic resin was measured in accordance with JIS K7162 on a test piece dried in advance at 80 ° C. under vacuum for 24 hours.
(5) Impact absorption performance of the resin impact absorbing member The impact absorbing performance of the resin impact absorbing member was evaluated using the IMATEK falling cone impact tester IM10, and the penetration direction of the hollow structure of the resin impact absorbing member The measurement was performed by measuring the initial impact load and the displacement required for shock absorption when the impact energy of 2500 J was applied in the coaxial direction. It can be said that the smaller the initial impact load and the displacement required for shock absorption, the better the shock absorption performance.

[Reference Example 1]
Carbon fiber “Tenax (registered trademark)” STS40-24KS (average fiber diameter 7 μm) manufactured by Toho Tenax Co., Ltd. cut to an average fiber length of 20 mm was used as the reinforcing fiber, and nylon 6 resin manufactured by Unitika Co., Ltd. was used as the thermoplastic resin. Using A1030 (breaking elongation of 50%), carbon fibers are two-dimensionally randomly oriented in the in-plane direction, and mixed so that the fiber volume content with respect to the entire fiber reinforced resin material is 35 Vol%. The fiber reinforced resin material A was produced by heating and compressing at a pressure of 2.0 MPa for 5 minutes using a press apparatus heated to 5 mm. The average fiber length of the obtained fiber reinforced resin material A was about 20 mm, the fiber volume content was about 35 Vol%, the compression modulus was 25 GPa, and the compression strength was 300 MPa.

[Reference Example 2]
A fiber reinforced resin material B was produced in the same manner as in Reference Example 1 except that the reinforced fibers were pulverized so that the average fiber length was about 0.5 mm and the fiber volume content was 15 Vol%. The average fiber length of the obtained fiber reinforced resin material B was about 0.5 mm, the fiber volume content was about 15 Vol%, the compression modulus was 7 GPa, and the compression strength was 110 MPa.

[Reference Example 3]
A fiber reinforced resin material C was produced in the same manner as in Reference Example 1 except that the average fiber length of the reinforced fibers was cut to 200 mm. The average fiber length of the obtained fiber reinforced resin material C was about 200 mm, the fiber volume content was about 35 Vol%, the compression modulus was 35 GPa, and the compression strength was 620 MPa.

[Reference Example 4]
Carbon fiber “Tenax (registered trademark)” STS40-24KS (average fiber diameter 7 μm) manufactured by Toho Tenax Co., Ltd., cut to an average fiber length of 20 mm as reinforcing fiber, and bisphenol A manufactured by Mitsubishi Chemical Co., Ltd. as thermosetting resin Type epoxy resin “jER (registered trademark)” 828 (breaking elongation 5%) was mixed by heating, and then a modified aromatic amine-based curing agent “jER Cure (registered trademark)” manufactured by Mitsubishi Chemical Corporation as a curing agent. W was additionally kneaded, and the resulting composition was stretched into a flat plate with a coater to obtain a thermosetting fiber reinforced resin prepreg. In addition, the ratio of the reinforcing fiber and the resin was adjusted so that the fiber volume content of the reinforcing fiber in the fiber-reinforced resin material was 35 Vol%. The obtained prepreg was set in a mold and cured for 4 hours under the conditions of a heating temperature of 180 ° C. and a pressure of 1.0 MPa to prepare a fiber reinforced resin material D. The fiber reinforced resin material D had an average fiber length of about 20 mm, a fiber volume content of about 35 Vol%, a compressive elastic modulus of 23 GPa, and a compressive strength of 280 MPa.

[Example 1]
Resin impact made of a hexagonal impact absorbing portion as shown in FIG. 9 is obtained by heating the fiber reinforced resin material A of Reference Example 1 to 280 ° C., performing cold press molding, and further vibration welding the flange portion. An absorbent member was produced. FIG. 9B shows a cross-sectional shape in a direction orthogonal to the shock absorbing direction of the shock absorbing portion shown in FIG. The dimensions of each part in this example are as follows: a = 44 mm, b = 31 mm, c = 15 mm, d = 105 degrees, e = 200 mm, and the thickness t1 of the outer cylinder part is 2.0 mm, which is uniform throughout the shock absorption direction. Thus, the cross-sectional shape in the direction orthogonal to the shock absorption direction is uniform. The maximum value of the ratio L1 / t1 between the distance L1 from the center of gravity in the cross-sectional shape in the direction orthogonal to the shock absorbing direction of the shock absorbing portion to the outer cylindrical portion in the same cross section and the thickness t1 of the outer cylindrical portion is 19. Yes, the maximum value of the ratio L2 / t2 between the side length L2 of each side of the hexagon and the average thickness t2 of the outer cylinder part constituting the side is 22.
The prepared resin shock absorbing member was set in a drop impact tester so that the shock absorbing direction was vertical, and an impact energy of 2500 J was applied in the coaxial direction with the shock absorbing direction. The displacement required for absorption was 45 mm.

[Example 2]
The fiber reinforced resin material A of Reference Example 1 is heated to 280 ° C., subjected to cold press molding, and further, the flange portion is vibration welded. A member was prepared. FIG. 10B shows a cross-sectional shape in a direction orthogonal to the shock absorbing direction of the shock absorbing portion shown in FIG. The dimensions of each part in this example are a = 34 mm, b = 200 mm, the thickness t1 of the outer tube part is uniform 2.0 mm, and the cross-sectional shape in the direction perpendicular to the shock absorption direction over the entire shock absorption direction is It is uniform. The maximum value of the ratio L1 / t1 between the distance L1 from the center of gravity in the cross-sectional shape in the direction orthogonal to the shock absorbing direction of the shock absorbing portion to the outer cylindrical portion in the same cross section and the thickness t1 of the outer cylindrical portion is 16. is there.
The prepared resin shock absorbing member was set in a drop impact tester so that the shock absorbing direction was vertical, and an impact energy of 2500 J was applied in the coaxial direction with the shock absorbing direction. The displacement required for absorption was 41 mm. In addition, the initial impact load ratio with respect to the initial impact load of Example 1 is 1.03, and the displacement ratio with respect to the displacement required for the impact absorption of Example 1 is 0.91, and the impact absorption performance substantially equivalent to that of Example 1 is obtained. Indicated.

[Example 3]
The fiber reinforced resin material A of Reference Example 1 is heated to 280 ° C., subjected to cold press molding, and the flange portion is vibration welded, whereby a resin shock absorption made up of a rectangular shock absorption portion as shown in FIG. A member was prepared. In addition, FIG.11 (b) shows the cross-sectional shape of the direction orthogonal to the shock absorption direction of the shock absorption part shown to the same figure (a). The dimensions of each part in this example are a = 90 mm, b = 20 mm, c = 90 degrees, d = 200 mm, and the thickness t1 of the outer cylinder part is uniform 2.0 mm. The cross-sectional shape in the direction orthogonal to the direction is uniform. The maximum value of the ratio L1 / t1 between the distance L1 from the center of gravity in the cross-sectional shape in the direction orthogonal to the shock absorbing direction of the shock absorbing portion to the outer cylindrical portion in the same cross section and the thickness t1 of the outer cylindrical portion is 23. In addition, the maximum value of the ratio L2 / t2 between the side length L2 of each side of the quadrangle and the average thickness t2 of the outer cylinder part constituting the side is 45.
The prepared resin shock absorbing member was set on a falling-pit impact test machine so that the shock absorbing direction was vertical, and an impact energy of 2500 J was applied in the coaxial direction with the shock absorbing direction. The displacement required for absorption was 66 mm. In addition, the initial impact load ratio with respect to the initial impact load of Example 1 is 1.05, and the displacement ratio with respect to the displacement required for the impact absorption of Example 1 is 1.47. The required displacement was slightly larger.

[Example 4]
Resin impact made of a hexagonal impact absorbing portion as shown in FIG. 9 is obtained by heating the fiber reinforced resin material A of Reference Example 1 to 280 ° C., performing cold press molding, and further vibration welding the flange portion. An absorbent member was produced. The dimensions of each part in this example are a = 66 mm, b = 49.5 mm, c = 22.5 mm, d = 105 degrees, e = 200 mm, and the thickness t1 of the outer cylinder part is uniform to 1.5 mm. The cross-sectional shape in the direction orthogonal to the shock absorption direction is uniform over the entire direction. The maximum value of the ratio L1 / t1 between the distance L1 from the center of gravity in the cross-sectional shape in the direction orthogonal to the shock absorbing direction of the shock absorbing portion to the outer cylindrical portion in the same cross section and the thickness t1 of the outer cylindrical portion is 38. In addition, the maximum value of the ratio L2 / t2 between the side length L2 of each side of the hexagon and the average thickness t2 of the outer cylinder part constituting the side is 44.
The prepared resin shock absorbing member was set in a drop impact tester so that the shock absorbing direction was vertical, and an impact energy of 2500 J was applied in the coaxial direction with the shock absorbing direction. The displacement required for absorption was 69 mm. In addition, the initial impact load ratio with respect to the initial impact load of Example 1 is 1.08, and the displacement ratio with respect to the displacement required for the impact absorption of Example 1 is 1.53. The required displacement was slightly larger.

[Comparative Example 1]
Resin impact made of a hexagonal impact absorbing portion as shown in FIG. 9 is obtained by heating the fiber reinforced resin material A of Reference Example 1 to 280 ° C., performing cold press molding, and further vibration welding the flange portion. An absorbent member was produced. The dimensions of each part in this comparative example are as follows: a = 88 mm, b = 62 mm, c = 15 mm, d = 105 degrees, e = 200 mm, and the thickness t1 of the outer cylinder part is 1.0 mm, which is uniform throughout the shock absorption direction. Thus, the cross-sectional shape in the direction orthogonal to the shock absorption direction is uniform. The maximum value of the ratio L1 / t1 between the distance L1 from the center of gravity in the cross-sectional shape in the direction orthogonal to the shock absorbing direction of the shock absorbing portion to the outer cylindrical portion in the same cross section and the thickness t1 of the outer cylindrical portion is 76. In addition, the maximum value of the ratio L2 / t2 between the side length L2 of each side of the hexagon and the average thickness t2 of the outer cylinder part constituting the side is 88.
The prepared resin shock absorbing member was set in a drop impact tester so that the shock absorbing direction was vertical, and an impact energy of 2500 J was applied in the coaxial direction with the shock absorbing direction. The displacement required for absorption was 180 mm. In addition, the initial impact load ratio with respect to the initial impact load in Example 1 is 1.00, and the displacement ratio with respect to the displacement required for the impact absorption in Example 1 is 4.00. The required displacement was 4 times larger.

[Comparative Example 2]
Resin impact made of a hexagonal impact absorbing portion as shown in FIG. 9 is obtained by heating the fiber reinforced resin material A of Reference Example 1 to 280 ° C., performing cold press molding, and further vibration welding the flange portion. An absorbent member was produced. The dimensions of each part in this comparative example are as follows: a = 66 mm, b = 49.5 mm, c = 22.5 mm, d = 105 degrees, e = 200 mm, and the thickness t1 of the outer cylinder part is 1.2 mm, and the impact absorption. The cross-sectional shape in the direction orthogonal to the shock absorption direction is uniform over the entire direction. The maximum value of the ratio L1 / t1 between the distance L1 from the center of gravity in the cross-sectional shape in the direction orthogonal to the shock absorbing direction of the shock absorbing portion to the outer cylindrical portion in the same cross section and the thickness t1 of the outer cylindrical portion is 47. 5 and the maximum value of the ratio L2 / t2 between the side length L2 of each side of the hexagon and the average thickness t2 of the outer cylinder part constituting the side is 55.
The prepared resin shock absorbing member was set in a drop impact tester so that the shock absorbing direction was vertical, and an impact energy of 2500 J was applied in the coaxial direction with the shock absorbing direction. The displacement required for absorption was 104 mm. In addition, the initial impact load ratio with respect to the initial impact load in Example 1 is 0.97, and the displacement ratio with respect to the displacement required for the impact absorption in Example 1 is 2.31. The required displacement was 2.31 times larger.

[Comparative Example 3]
Using the fiber reinforced resin material B of Reference Example 2, a resin impact absorbing member having the same shape was produced in the same manner as in Example 1. The prepared resin shock absorbing member was set on a falling-pit impact test machine so that the shock absorbing direction was vertical, and an impact energy of 2500 J was applied in the coaxial direction with the shock absorbing direction. The displacement required for absorption was 165 mm. In addition, the initial impact load ratio with respect to the initial impact load in Example 1 is 0.36, and the displacement ratio with respect to the displacement required for absorbing the impact in Example 1 is 3.67. Compared with Example 1, the impact load is While it was 0.36 times better, the displacement required for shock absorption was 3.67 times larger.

[Comparative Example 4]
Using the fiber reinforced resin material C of Reference Example 3, a resin impact absorbing member having the same shape was produced in the same manner as in Example 1. The prepared resin shock absorbing member was set in a drop impact tester so that the shock absorbing direction was vertical, and an impact energy of 2500 J was applied in the coaxial direction with the shock absorbing direction. The displacement required for absorption was 28 mm. In addition, the initial impact load ratio with respect to the initial impact load in Example 1 is 2.10, and the displacement ratio with respect to the displacement required for the impact absorption in Example 1 is 0.62. The required displacement was as good as 0.62 times, while the initial impact load was 2.10 times as great.

[Comparative Example 5]
The thermosetting fiber reinforced resin prepreg obtained in Reference Example 4 was set in a mold and cured for 4 hours under the conditions of a heating temperature of 180 ° C. and a pressure of 1.0 MPa. A shock-absorbing member made of curable resin was produced. The prepared resin shock absorbing member was set in a drop impact tester so that the shock absorbing direction was vertical, and an impact energy of 2500 J was applied in the coaxial direction with the shock absorbing direction. The displacement required for absorption was 91 mm. Further, the initial impact load ratio with respect to the initial impact load in Example 1 is 0.94, and the displacement ratio with respect to the displacement required for the impact absorption in Example 1 is 2.02. The required displacement was 2.02 times larger.

  The resin-made impact absorbing member of the present invention is used to suppress the impact to the other end side by absorbing the impact energy input to one end by the impact absorbing portion. It can be used for an impact absorbing device.

DESCRIPTION OF SYMBOLS 1 Shock absorption part 2 Outer cylinder part 3 Hollow part 4 Cross section of the direction orthogonal to the shock absorption direction of the shock absorption part 5 Point on the outer cylinder part on arbitrary cross sections 4 6 Gravity center on arbitrary cross sections 4 7 Optional cross sections Side of outer cylinder on 4 X Shock absorption direction

Claims (5)

A resin-made impact-absorbing member comprising a fiber-reinforced resin material containing a reinforced fiber and a thermoplastic resin, and having a shock-absorbing portion having a hollow structure composed of an outer tube portion and a hollow portion,
The reinforcing fiber has an average fiber length of 1 to 100 mm, the thermoplastic resin has a breaking elongation of 10% or more, the fiber reinforced resin material has a compressive modulus of 10 GPa or more, and a compressive strength of 150 to 500 MPa,
The cross-sectional shape in a direction perpendicular to the shock absorption direction of the shock absorbing portion is a uniform shape over the entire region of the shock absorption direction,
The impact absorbing portion has a maximum value L40 of a ratio L1 / t1 between the distance L1 from the center of gravity in the cross-sectional shape in the direction orthogonal to the impact absorbing direction to the outer cylindrical portion in the same cross section and the thickness t1 of the outer cylindrical portion. A resin-made shock absorbing member, characterized in that:   The cross-sectional shape in the direction orthogonal to the shock absorbing direction of the shock absorbing part is a polygon, and the ratio L2 between the side length L2 at each side of the polygon and the average thickness t2 of the outer cylinder part constituting the side. The resin impact absorbing member according to claim 1, wherein the maximum value of / t2 is 40 or less. The resin shock absorbing member according to claim 1 , wherein the shock absorbing portion is made of a single fiber reinforced resin material . The resin shock absorbing member according to claim 3, wherein the fiber orientation of the fiber reinforced resin material forming the shock absorbing portion does not change for each portion of the shock absorbing portion . The vehicle component comprised from the resin-made impact-absorbing member of any one of Claims 1-4.