JP2010006245A - Impact energy absorbing body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact energy absorbing body for securing a sufficient impact energy absorption amount while suppressing an increase in weight even when a component in contact with the impact energy absorbing body is arranged at an offset position. <P>SOLUTION: The impact energy absorbing body is arranged between a component A and a component B and at a position offset from the component B when mounted to a vehicle, and includes an outer portion and an inner portion. Each of the outer portion and the inner portion has a frame body which extends in an arrangement direction of the component A, the impact energy absorbing body, and the component B, and grid-like ribs which are arranged in the frame body and extend in the arrangement direction. In one of the outer portion and the inner portion which is arranged apart from the component B when mounted to the vehicle, a rib at a position that overlaps the component B in the arrangement direction when mounted at the vehicle is thinned, or made thinner than the other rib. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an impact energy absorber made of resin, and more particularly to an impact energy absorber having a rib when a part in contact with the impact energy absorber is disposed at an offset position.

  Conventionally, metal members are mostly used for members that require impact resistance, such as boats, trains, and automobile outer plate members. However, they are difficult to process because they are heavy and difficult to process. Replacement has been considered. In addition, resin can absorb impact energy more efficiently than iron, depending on how it is used, and in recent years, its use in automobile outer plate members and automobile structural members has increased.

  As an impact energy absorbing structure of an automobile, an impact absorber combining lattice ribs and box shapes is known. For example, Patent Documents 1 and 2 disclose box-shaped buffer members made of ribs formed in a lattice shape. Patent Document 3 describes a structure in which a box-shaped bumper stay divided into two parts is combined with a mounting flange.

  However, as described in Patent Document 4, there is a case where the impact energy absorber has to be arranged at a position offset from the surrounding parts in the layout of the vehicle.

  Nonetheless, Patent Documents 1 and 2 describe a box-shaped cushioning member made of ribs formed in a lattice shape, but particularly describe the case where they are arranged at positions offset from peripheral parts. There is a possibility that sufficient impact energy absorption cannot be secured.

  Further, Patent Document 3 describes a structure in which a box-shaped bumper stay divided into two parts is combined by a mounting flange. By using bolts for the mounting structure of the bumper stay, the vehicle body width direction can be viewed from an oblique direction. When a load is input, the structure is such that a folding force is prevented from being generated in the front side member. However, the case where the bumper stay is arranged at a position offset from the front side member is not particularly described, and there is a possibility that a sufficient impact energy absorption amount cannot be secured. In particular, when a load is input from an oblique direction with respect to the vehicle body height direction, a folding force is generated in the front side member, and there is a possibility that a sufficient amount of impact energy absorption cannot be ensured.

And in patent document 4, with respect to the subject that a bumper beam and a side frame are arrange | positioned in the position offset, the impact load at the time of a collision is made into the side shape by making it into the cross-sectional shape which expanded the cross-sectional part in a part of bumper beam. It is described that it is transmitted almost straight to the frame and effectively absorbs impact energy. However, with this method, the weight increases due to the expansion of the cross-sectional shape, and this method may not be adopted when other components are arranged in the periphery.
JP 9-123753 A JP 2003-48585 A JP-A-6-171443 JP 2002-29342 A

  An object of the present invention is to provide an impact energy absorber capable of securing a sufficient amount of impact energy absorption while suppressing an increase in weight even when a component in contact with the impact energy absorber is disposed at an offset position. It is in.

In order to achieve the above object, the present invention has one of the following configurations.
(1) An impact energy absorber provided with an outer portion and an inner portion, which is disposed between the component A and the component B and offset from the component B when the vehicle is mounted. Inner portions are respectively provided in the arrangement direction of the component A, the impact energy absorber, and the component B, and the frame body, and extend in the arrangement direction. One of the outer part and the inner part arranged at a position away from the part B when the vehicle is mounted corresponds to a position overlapping the part B in the arrangement direction when the vehicle is mounted. An impact energy absorber, characterized in that the ribs are thinned out or are thinner than other ribs.
(2) The impact energy absorber according to claim 1, wherein the outer portion and the inner portion are configured separately and are stacked and disposed at a position offset from the component B when the vehicle is mounted.
(3) The impact energy absorber according to claim 1 or 2, wherein the part A is a bumper cover and the part B is a frame.
(4) The outer part and the inner part are composed of a thermoplastic resin (A) and a resin (B) having a reactive functional group, and satisfy the following relationships (I) and (II): The impact energy absorber according to any one of claims 1 to 3, comprising a resin composition.
(I) Assuming that the tensile elastic modulus at the tensile speeds V1 and V2 after the tensile yield elongation in the tensile test is E (V1) and E (V2), E (V1)> E ( V2)
(II) After the tensile yield elongation in the tensile test, assuming that the stresses at V1 and V2 in the tensile elongation ε are σ (V1, ε) and σ (V2, ε), when V1 <V2, σ ( V1, ε)> σ (V2, ε)
In the present invention, the offset refers to a state in which the position where the impact energy absorber and other components are in contact with each other is shifted in a plane perpendicular to the load direction with reference to the center of gravity of the impact energy absorber.

  According to the present invention, as will be described below, even when a component in contact with an impact energy absorber is disposed at an offset position, an impact energy absorption that can secure a sufficient amount of impact energy absorption compared to the conventional case. The body can be obtained without incurring an increase in weight.

  That is, the impact energy absorber of the present invention is installed, for example, in a bumper of an automobile, and is disposed between the component A and the component B and at a position offset from the component B when the vehicle is mounted. An impact energy absorber including an outer part and an inner part. And the outer part and the inner part are provided inside the frame body extending in the arrangement direction of the component A, the impact energy absorber, and the component B, respectively, and extend in the arrangement direction. Further, one of the outer part and the inner part that is disposed at a position away from the part B when the vehicle is mounted corresponds to a position that overlaps the part B in the arrangement direction when the vehicle is mounted. The ribs are thinned out or are thinner than other ribs. As a result, the side of the outer part and the inner part where the ribs are thinned or the thin ribs are provided (hereinafter referred to as “thinning side”) buckles, and the impact energy absorber as a whole The part B (such as a frame) rotates with the thinned ribs or thick ribs on the fulcrum, and the ribs of the outer part and inner part are not thinned or the rib thickness is constant. A certain side (hereinafter referred to as “the side that has not been thinned out”) buckles at a portion in contact with the part B (frame or the like). Therefore, a large impact energy can be absorbed.

  Thus, while reducing the weight of the impact energy absorber by thinning out the rib on one of the outer part and the inner part, or by providing a rib that is partially thinner than the other ribs. However, the deformation mode of the impact energy absorber can be controlled to ensure a sufficient energy absorption amount.

  Embodiments of the present invention will be described below with reference to the drawings.

  The impact energy absorber of the present invention is installed in a bumper or the like of an automobile. When the vehicle is mounted, for example, between the bumper cover (part A) and the frame (part B) and the frame (part B). ) And an impact energy absorber having an outer part and an inner part, which are arranged at offset positions.

  Specifically, for example, an impact energy absorber 10 made of a single molded product as shown in FIG. 1 having a frame body and grid-like ribs, an outer portion 11 and an inner portion as shown in FIG. Can be exemplified as an impact energy absorber 10 that is configured as a separate body and is stacked and disposed when the vehicle is mounted. 1 and 2 are perspective views of the impact energy absorber 10 as viewed from one side, and (b) is a perspective view of the impact energy absorber as viewed from the other side. FIG. Moreover, in the aspect shown in FIG. 1 and FIG. 2, although there exists a difference whether the outer part 11 and an inner part are an integrally molded product, or it is a different body, each member demonstrated with the same name is fundamentally the same. This has an operational effect and is denoted by the same reference numerals in the drawings.

  The impact energy absorber 10 shown in FIG. 1 is a single molded product, and a grid-like rib 13 is provided in a frame 15. The frame body 15 and the rib 13 respectively extend in the arrangement direction (hereinafter referred to as arrangement direction) of the part A (bumper cover or the like), the impact energy absorber, and the part B (frame or the like) when the vehicle is attached.

  And in this invention, one arrange | positioned in the position away from the components B offset among the outer part which becomes an outer side at the time of vehicle attachment, and the inner part which becomes an inner side is as follows. That is, the rib corresponding to the position overlapping the component B in the arrangement direction when the vehicle is mounted is thinned out or is thinner than other ribs. FIG. 1 shows an aspect in which the outer portion 11 is disposed at a position away from the offset component B, and ribs corresponding to positions overlapping the component B (frame, etc.) are thinned out in the arrangement direction when the vehicle is mounted. It is in a state (rib thinning portion 14). At this time, the above-described effects can be obtained even if the ribs of the portion are not thinned out and are thinner than the other ribs. When the inner part, not the outer part, is arranged at a position away from the offset part B, a rib thinning part or a thin rib may be provided on the inner part, not the outer part.

  The impact energy absorber 10 shown in FIG. 2 has basically the same configuration as the impact energy absorber shown in FIG. 1 except that the outer portion 11 and the inner portion 12 are separate. That is, each of the outer part 11 and the inner part 12 has a form in which a grid-like rib 13 is provided in a frame 15, and these are stacked when the vehicle is mounted to constitute one impact energy absorber 10. .

  The frame body 15 and the rib 13 respectively extend in the arrangement direction of the part A (bumper cover or the like), the impact energy absorber, and the part B (frame or the like) when the vehicle is mounted, and the outer part 11 and the inner part 12. Among them, one of the ribs disposed at a position away from the offset component B and the rib corresponding to the position overlapping the component B in the arrangement direction when the vehicle is mounted is thinned, or thicker than other ribs. Is in a thin state.

  FIG. 2 shows an aspect in which the outer portion 11 is disposed at a position away from the offset component B, and ribs corresponding to positions overlapping the component B (frame, etc.) are thinned out in the arrangement direction when the vehicle is mounted. It is in a state (rib thinning portion 14). At this time, the above-described effects can be obtained even if the ribs of the portion are not thinned out and are thinner than the other ribs. When the inner part, not the outer part, is arranged at a position away from the offset part B, a rib thinning part or a thin rib may be provided on the inner part, not the outer part.

  As shown in FIG. 2, when the outer part and the inner part of the impact energy absorber are separated, the fastening method of the outer and the inner is not particularly limited, but it is easy to fasten with a snap fit, a clip, a bolt, or the like. preferable. For such fastening, as shown in FIG. 2, it is preferable to provide a flange portion 16 on the outer portion 11 and the inner portion 12, and attach and fasten a snap fit, a clip, and a bolt to the flange portion 16.

  The material constituting the outer part and the inner part of these impact energy absorbers is preferably a resin composition. The resin constituting such a resin composition is not particularly limited, but is preferably a thermoplastic resin. By using a thermoplastic resin, melt molding becomes possible and productivity can be improved. Examples of preferred thermoplastic resins include polypropylene, styrene, nylon, polyester, polycarbonate, polyacetal, polyurethane and the like, and these can also be used as polymer alloys.

Among them, as a resin constituting the impact energy absorber, a thermoplastic resin (A) and a resin (B) having a reactive functional group are blended, and the thermoplastic resin having the following characteristics (I) and (II) It is preferable to use a composition.
(I) Assuming that the tensile elastic modulus at the tensile speeds V1 and V2 after the tensile yield elongation in the tensile test is E (V1) and E (V2), E (V1)> E ( V2)
(II) If the stress at V1 and V2 in the tensile elongation ε after the tensile yield elongation in the tensile test is σ (V1, ε) and σ (V2, ε), σ ( V1, ε)> σ (V2, ε)
If the thermoplastic resin composition satisfying the above (I) and (II) is used as a constituent material of the outer part and the inner part, it becomes a material excellent in toughness in the case of a sudden deformation such as a collision, The amount of impact energy absorbed at the time of collision increases.

In addition, as a thermoplastic resin composition which has the characteristics of said (I) and (II), the thermoplastic resin composition shown by Unexamined-Japanese-Patent No. 2006-089701 is mentioned. This thermoplastic resin composition has a reactive function with the thermoplastic resin (A) using a twin screw extruder of L / D> 45, where L is the screw length of the twin screw extruder and D is the screw diameter. It is manufactured by melt-kneading a resin (B) having a group, and has a structure shown in either of the following (a) and (b): (a) Thermoplastic resin (A) And one of the resin (B) having a reactive functional group forms a continuous phase and the other forms a dispersed phase, and fine particles having an average particle diameter of 300 nm or less exist in these continuous phase and dispersed phase, and occupy the cross section. Structure in which area ratio of dispersed phase to continuous phase is 40/60 to 60/40 (b) The thermoplastic resin (A) and the resin (B) having a reactive functional group together form a continuous phase, and these Average particle diameter of 300 nm or less in both continuous phases In which the area ratio of both continuous phases in the cross section is 40/60 to 60/40. Here, the thermoplastic resin (A) is polyamide resin, polyester resin, polyphenylene sulfide resin, polyacetal resin, styrene. It is a thermoplastic resin composition that is at least one selected from a series resin, and the resin (B) having a reactive functional group is a thermoplastic resin composition that is a rubbery polymer having a reactive functional group. The reactive functional group is at least one functional group selected from an epoxy group, an acid anhydride group, and an oxazoline group.

  The blending ratio between the thermoplastic resin (A) and the resin (B) having a reactive functional group is preferably 95/5 to 5/95 by weight.

  E (V1), E (V2), σ (V1, ε), and σ (V2, ε) are measured according to the tensile test method specified in the ASTM D-638-96 standard. E represents the slope of the initial straight line portion of the stress-strain curve, and σ represents the stress at the tensile elongation ε. Further, as shown in FIG. 2, when the outer part and the inner part of the impact energy absorber are separated, they can be made of different materials. That is, for example, nylon can be used as the resin constituting the outer, and polypropylene can be used as the resin constituting the inner.

  In the impact energy absorber as shown in FIGS. 1 and 2, it is preferable that the end surface near the component B to be offset is closed in order to increase the amount of impact energy absorbed.

  The impact energy absorber of the present invention as described above is incorporated in a vehicle, for example, as shown in FIGS. 3 to 5 are schematic views when the flange portion 16 is provided in the impact energy absorber for automobile according to the embodiment of the present invention as shown in FIG. 3A is a cross-sectional view in the horizontal direction of the vehicle body around the impact energy absorber, FIG. 3B is a cross-sectional view in the vertical direction of the vehicle body around the impact energy absorber, and FIG. 4 is a perspective view of the periphery of the shock energy absorber. 5A is a horizontal sectional view of the vehicle body, and FIG. 5B is a vertical sectional view of the vehicle body.

  3 to 5, the impact energy absorber 10 is fastened to the frame 20 by the impact energy absorber mounting jig 40 and the bolt 41, and the bumper cover 30 (part A) and the frame 20 (part B). And at a position offset from the frame 20. Note that the fastening method is not particularly limited as long as the energy absorption amount can be secured. Moreover, also when using the impact energy absorber 10 in which the outer part 11 and the inner part 12 are comprised separately as shown in FIG. 2, it can be integrated similarly to FIGS.

  The impact energy absorber of the present invention can be used not only in a bumper of a vehicle such as an automobile but also in any location where impact resistance is required, such as in a door or in a fender. Examples of the vehicle include a motorcycle, a railway vehicle, and a ship. In designing the impact energy absorber, it is possible to confirm the impact energy absorption performance by actually making a prototype and experiment, and to determine the optimum shape based on the result, but it is possible to make a virtual simulation by computer simulation. A method of determining an optimum shape based on a typical test result is preferably used.

  Examples and Comparative Examples are shown below, but the present invention is not limited thereto.

  In the examples and comparative examples, the energy absorption performance was evaluated as shown in FIG. That is, FIG. 6 is a schematic diagram of a collision test, 50 is an impactor, and 20 is a frame. In this test, when the impactor 50 collides with the impact energy absorber 10, the displacement of the impactor 50 and the reaction force generated between the impactor 50 and the impact energy absorber 10 are measured. The history area of this load (reaction force) -displacement diagram is the amount of energy absorbed by the impact energy absorber.

  The impactor 50 was a plate having a weight of 260 kg (120 mm × 120 mm × 5 mm), and was made to collide with the impact energy absorber 10 so that the collision speed was 5 m / sec. Since variations occurred in the test, the N number was set to 5 times, and the energy absorption amount was evaluated by an arithmetic average of 5 times.

Example 1
The flange part 16 was provided in the center part of the impact energy absorber 10 shown in FIG. 1, it fixed as shown in FIG. 7, and the impact resistance characteristic was evaluated.

  In the impact energy absorber 10, the rib corresponding to the position overlapping the frame 20 in the arrangement direction when the vehicle is mounted is thinned out in the outer portion 11 disposed at a position away from the frame 20 when the vehicle is mounted. Using nylon 6 resin “Amilan” UTN141 manufactured by Toray Industries, Inc., it was molded by injection molding. A flange portion 16 of 120 mm × 120 mm is integrally provided at the center in the height direction of the frame 15 of 70 mm × 70 mm × height 100 mm, and the end surface of the frame 15 on the frame 20 side is closed. The frame 15 has a thickness of 2 mm, a rib thickness of 2 mm, and a flange thickness of 2 mm. Further, a draft angle was provided so that the mold of the rib and the outer part could be released to the opening side and the inner part of the frame could be released to the closing side after injection molding. The obtained impact energy absorber 10 weighed 159 g.

  An impactor 50 was made to collide with the impact energy absorber 10, and the amount of energy absorbed when the impactor 50 was displaced by 35 mm was evaluated.

  The evaluation results of the present invention are shown in FIG. 9 (a), FIG. As a result of the evaluation, the impact energy absorber 10 is rotated in a direction in which the rib is not thinned (the vehicle body upward direction) with the frame 20 as a fulcrum by buckling the portion where the rib of the outer portion 11 is thinned, Further, the impact energy absorber 10 and the frame 20 were also buckled at the contact portion. When the impactor displacement was 35 mm, the amount of energy absorbed by the impact energy absorber 10 was 589.4 J. Thus, the impact energy absorber 10 is reduced in weight by thinning out the ribs corresponding to the positions overlapping the frame 20 in the arrangement direction when the vehicle is mounted on the outer portion 11 disposed at a position away from the frame 20 when the vehicle is mounted. Meanwhile, the deformation mode of the impact energy absorber 10 can be controlled.

(Comparative Example 1)
In Comparative Example 1, the ribs in the impact energy absorbing body were not thinned, and other conditions were the same as in Example 1 and the impact resistance characteristics were evaluated. At this time, the weight of the impact energy absorber 10 was 164 g.

  The evaluation results are shown in FIG. 9B, FIG. As a result of the evaluation, the impact energy absorber 10 buckled at a portion in contact with the frame 20, rotated in the vehicle body downward direction with the frame 20 as a fulcrum, and further entered a deformation mode in which the frame 20 disengages from the vehicle body upward. When the impactor displacement was 35 mm, the energy amount absorbed by the impact energy absorber 10 was 533.3 J, and the energy absorption amount was 56.1 J smaller than that in Example 1. Further, the weight was 5 g heavier than that of Example 1.

(Comparative Example 2)
The outer portion 11 disposed at a position away from the frame 20 when the vehicle is mounted is the same as in the first embodiment except that a rib thinning portion is provided at a position that does not overlap the frame 20 in the arrangement direction when the vehicle is mounted. Impact properties were evaluated. At this time, the weight of the impact energy absorber 10 was 159 g.

  The results of the evaluation are shown in FIG. 9 (c), FIG. As a result of the evaluation, the impact energy absorber 10 rotates in a direction in which the rib is not thinned (the vehicle body downward direction) with the frame 20 as a fulcrum by buckling the portion where the rib of the outer portion 11 is thinned, Further, the impact energy absorber 10 and the frame 20 were buckled at the portion where they contacted each other. As a result, the impact energy absorber 10 is in a deformation mode in which the impact energy absorber 10 is further disengaged from the frame 20 in the upward direction of the vehicle body as compared with the comparative example 1. When the impactor displacement was 35 mm, the amount of energy absorbed by the impact energy absorber 10 was 520.9 J, and the amount of energy absorbed was 68.5 J smaller than that of Example 1, although the weight was the same.

(Example 2)
The impact energy absorber 10 was composed of two parts (an outer part 11 and an inner part 12) as shown in FIG. 2, and was fixed as shown in FIG.

  The impact energy absorber 10 was formed by injection molding using nylon 6 resin “Amilan” UTN141 manufactured by Toray Industries, Inc. The outer portion 11 is integrally provided with a flange portion 16 of 120 mm × 120 mm on the end surface in the height direction of the frame body 15 of 70 mm × 70 mm × height 50 mm, and the flange portion side end surface of the frame body 15 is closed. The end surface opposite to the flange portion 16 was opened. The frame thickness was 2 mm, the rib thickness was 2 mm, and the flange thickness was 2 mm. In addition, the rib corresponding to the position overlapping the frame 20 in the arrangement direction when the vehicle is mounted is thinned out. On the other hand, the inner portion 12 has the same external dimensions and thickness as the outer portion 11 except that the rib is not thinned, the flange portion side of the frame body is opened, and the opposite side to the flange portion 16 is closed. Further, a draft angle was provided so that both the outer part 11 and the inner part 12 could be released from the mold. The separate outer part 11 and inner part 12 are fastened with a snap fit 17 in the flange part 16 to obtain an impact energy absorber 10. The weight of the obtained impact energy absorber 10 was 203 g.

  An impactor 50 was made to collide with the impact energy absorber 10, and the amount of energy absorbed when the impactor 50 was displaced by 35 mm was evaluated.

  The evaluation results of the present invention are shown in FIG. As a result of the evaluation, as for the deformation mode, as in the deformation mode of the first embodiment (FIG. 9A), the portion where the rib is thinned out in the portion where the outer portion 11 and the impactor 50 are in contact with each other. The impact energy absorber rotated in the direction where the ribs were not thinned out (upward in the vehicle body) with the frame 20 as a fulcrum, and buckled even at the portion where the inner portion 12 and the frame 20 were in contact. When the impactor displacement was 35 mm, the amount of energy absorbed by the impact energy absorber 10 was 489.4J. By thinning out the ribs of the outer 11 in this manner, the deformation mode of the impact energy absorber 10 can be controlled while reducing the weight of the impact energy absorber 10.

(Comparative Example 3)
The outer ribs were not thinned, and the other conditions were the same as in Example 2, and the impact resistance characteristics were evaluated. At this time, the weight of the impact energy absorber 10 was 207 g.

The evaluation results are shown in FIG. As a result of the evaluation, the deformation mode is buckled at the portion where the inner portion 12 and the frame 20 are in contact with each other, as in the deformation mode of the first comparative example (FIG. 9B). The deformation mode deviated in the direction. When the impactor displacement was 35 mm, the energy amount absorbed by the impact energy absorber 10 was 467.9 J, and the energy absorption amount was 21.5 J smaller than that in Example 1. Further, the weight was 4 g heavier than that of Example 1.
(Comparative Example 4)
Example 2 except that a rib thinning portion is provided at a position where the outer portion 11 arranged away from the frame 20 when attached to the vehicle does not overlap the frame 12 in the stacking direction of the outer portion 11 and the inner portion 12 when the vehicle is attached. The impact resistance characteristics were evaluated in the same manner as described above. At this time, the weight of the impact energy absorber 10 was 203 g.

  The evaluation results are shown in FIG. As a result of the evaluation, as for the deformation mode, as in the deformation mode of Comparative Example 2 (FIG. 9C), the impact energy absorber 10 is formed by buckling the portion where the rib of the outer portion 11 is thinned. The frame was rotated in the direction where the ribs were not thinned out (the vehicle body downward direction) with the frame as a fulcrum, and the inner 12 was also buckled at the portion in contact with the frame 20. As a result, the impact energy absorber 10 is in a deformation mode in which the impact energy absorber 10 is further disengaged from the frame 20 in the upward direction of the vehicle body as compared with the comparative example 1. When the impactor displacement was 35 mm, the amount of energy absorbed by the impact energy absorber 10 was 458.8 J, and the amount of energy absorbed was 30.6 J smaller than that of Example 1, although the weight was the same.

  The impact energy absorber of the present invention can be used for motorcycles, railway vehicles, ships and the like.

It is a schematic perspective view of the impact energy absorber which shows one Embodiment of this invention. It is a schematic perspective view of the impact energy absorber which shows other embodiment of this invention. It is a schematic diagram at the time of incorporating the impact energy absorber in an automobile showing one embodiment of the present invention. It is a schematic diagram at the time of incorporating the impact energy absorber in an automobile showing one embodiment of the present invention. It is a schematic diagram at the time of incorporating the impact energy absorber in an automobile showing one embodiment of the present invention. It is a schematic diagram of a collision test. It is a schematic diagram at the time of evaluating the impact characteristic of an impact energy absorber in Example 1 and Comparative Examples 1 and 2. It is a schematic diagram at the time of evaluating the impact characteristic of an impact energy absorber in Example 2 and Comparative Examples 3 and 4. It is a deformation | transformation schematic diagram of the impact energy absorber in Example 1 and Comparative Examples 1 and 2. FIG. It is a graph of the impact test result in Example 1 and Comparative Examples 1 and 2. It is a graph of the impact test result in Example 2 and Comparative Examples 3 and 4.

Explanation of symbols

10: Impact energy absorber 11: Outer part 12: Inner part 13: Rib 14: Rib thinning part 15: Frame body 16: Flange part 17: Snap fit 18: Bolt fastening hole 20: Frame (component B)
21: Side member 30: Bumper cover (part A)
40: Impact energy absorber mounting jig 41: Impact energy absorber mounting bolt 50: Impactor

Claims (4)

An impact energy absorber provided with an outer part and an inner part between parts A and B when mounted on a vehicle and at a position offset from part B, wherein the outer part and the inner part are , A frame extending in the arrangement direction of the component A, the impact energy absorber, and the component B, respectively, and a lattice-like shape provided inside the frame and extending in the arrangement direction. One of the outer part and the inner part arranged at a position away from the part B at the time of mounting the vehicle is a rib corresponding to a position overlapping the part B in the arrangement direction at the time of mounting the vehicle. An impact energy absorber characterized by being thinned out or being thinner than other ribs. The impact energy absorber according to claim 1, wherein the outer part and the inner part are configured separately and are stacked and disposed at a position offset from the component B when the vehicle is mounted. The impact energy absorber according to claim 1 or 2, wherein the component A is a bumper cover and the component B is a frame. The outer part and the inner part are composed of a thermoplastic resin (A) and a resin (B) having a reactive functional group, and satisfy the following relationships (I) and (II): The impact energy absorber according to claim 1, comprising:
(I) Assuming that the tensile elastic modulus at the tensile speeds V1 and V2 after the tensile yield elongation in the tensile test is E (V1) and E (V2), E (V1)> E ( V2)
(II) If the stress at V1 and V2 in the tensile elongation ε after the tensile yield elongation in the tensile test is σ (V1, ε) and σ (V2, ε), σ ( V1, ε)> σ (V2, ε)

Images