JP2007190971A - Impact absorbing member for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve impact absorbing performance by securing crushing stroke quantity in crushing deformation. <P>SOLUTION: An impact absorbing member EA for a vehicle is constituted of a plurality of impact absorbing projected parts 10 showing a circular truncated conical shape arranged with required intervals between each other, a surface type connecting part 18 to connect and support base parts of the impact absorbing projected parts to each other, a top surface deformation facilitating part 40 provided on a top surface part 16 of each of the impact absorbing projected parts 10 and a side surface deformation allowing part 30 provided on an outer peripheral side surface part 12 of each of the impact absorbing projected parts 10. Each of the impact absorbing projected parts 10 shows a cup shape projected to one side of the surface shape connecting part 18. The top surface deformation facilitating part 40 is constituted of a plurality of top surface deforming ribs 43 radially extended outward in the diametrical direction from centers of the top surface parts 16 and the side surface deformation allowing part 30 is constituted of side surface openings 32 formed at positions in conformity with central lines passing the centers of top surface openings 42 formed on the top surface parts 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle impact absorbing member made of a synthetic resin.

  In recent years, vehicles such as automobiles have been demanded not only to protect passengers in the event of a collision accident, but also to establish safety measures for pedestrian protection. ) Is moderately deformed, so-called “pedestrian injury reducing body” has been developed that absorbs shock. In other words, if a running vehicle accidentally collides with a pedestrian, the pedestrian will be struck against the bonnet or fender of the body by the reaction, so the impact force caused by the collision of the bonnet or fender with the pedestrian By adopting a structure that deforms in a concave manner, measures are taken to mitigate the impact and reduce the degree of injury of the pedestrian.

  However, even if the body made of steel is designed to have a shock absorbing structure that is easily deformed, it is often not possible to achieve sufficient shock absorption by itself. For this reason, when an appropriate vehicle impact absorbing member (also referred to as an energy absorber (EA)) is interposed inside the body, and an impact that causes deformation of the body is applied from the outside, the vehicle impact absorbing member is applied. In many cases, the absorbing member is crushed and deformed so as to absorb impact. This vehicle impact absorbing member has a wide variety of shapes, structures, materials, etc., for example, (1) hard urethane molded bodies, (2) synthetic resin structures, (3) foam beads, (4 ) Aluminum and steel rib structures have been put to practical use. Such a vehicle impact absorbing member is disclosed in Patent Document 1, for example.

Here, as a test for measuring the impact absorbing performance of the vehicle impact absorbing member, for example, a “head impact test” can be cited. This head impact test uses a headform impactor, and allows the headform (head model) to be free-flighted at a speed of 24 km / h (15 miles / h) on a sample material of a specified size set on a set base. The HIC (Head Injury Criteria) value is calculated based on the data acquired at this time. This HIC value is a numerical value obtained by substituting the time history data of the acceleration generated in the headform at the time of the collision into a required evaluation formula, and it is evaluated that the smaller the numerical value is, the head injury can be reduced. In general, it is desirable that “1000” is an evaluation standard value smaller than this.
JP-A-9-150692

  By the way, in recent years, in an impact absorbing member for a vehicle, when an impact from the outside is applied, it is not limited to simply deforming in a crushing manner and absorbing the impact, but how to effectively and effectively absorb the impact (impact There is a need to improve impact absorption performance by increasing the amount of absorption. For example, FIG. 13 and FIG. 14 are partial perspective views schematically showing the buffer disclosed in Patent Document 1. FIG. A shock absorber EA1 that is a shock absorbing member for a vehicle has a cup-like body 60 that is made of resin such as polypropylene and that exhibits a shock absorbing function. The bridge 66 has a structure coupled vertically and horizontally.

  However, in such a structure, even if the bowl-shaped bridge 66 is set to be appropriately thick, for example, when an external force is partially applied as illustrated in FIG. Cannot be regulated. When the cup-like body 60 is displaced in this way, appropriate crushing deformation is less likely to occur with respect to external force, so that there is a drawback that efficient shock absorption cannot be expressed.

  Further, each cup-like body 60 constituting the buffer body EA1 is a bottomed type that does not have any openings in the top surface portion 68 and the outer peripheral side surface portion 62, and its rigidity is considerably high. Moreover, each bridge 66 that supports the skirt portion 64 of each cup-shaped body 60 from four directions acts like a so-called “support bar” when the cup-shaped body 60 is crushed and deformed. In some cases, open deformation is restricted. For this reason, as illustrated in FIG. 16, the cup-shaped body 60 not only restricts the expansion deformation of the skirt portion 64 but also restricts the reduction deformation of the top surface portion 68, and thus a large load is applied. The outer peripheral side surface portion 62 is bent and deformed into a rib shape, and after deformation to a level that is less than half of the projection height H before deformation, a very large load is required for further deformation, and the stroke itself is also It will decrease. That is, a bottomed state is generated early in the course of crushing deformation, and the amount of shock absorption is reduced. Accordingly, there is a problem that suitable shock absorption is not expressed.

  Patent Document 1 also exemplifies an opening-type cup-like body 60 in which an upper portion corresponding to the top surface portion is completely opened. Such an open-type cup-shaped body 60 has an advantage that the crushing stroke amount can be easily secured because the upper portion is open, and the reduction deformation of the upper portion is expressed very easily. However, since the amount of shock absorption at the time of the crushing deformation is reduced by the amount that the crushing deformation is easily expressed, it cannot be evaluated that the suitable shock absorption can be achieved.

  Accordingly, an object of the present invention is to provide a vehicle impact absorbing member that efficiently secures a crush stroke amount at the time of crushing deformation and improves impact absorbing performance.

In order to solve the problem and achieve the intended purpose, the invention according to claim 1
A vehicle impact absorbing member made of synthetic resin,
A plurality of shock-absorbing protrusions having a cup shape with a truncated cone shape arranged at a necessary interval from each other;
A planar connecting part for connecting and supporting the hem part of each of the shock absorbing protrusions;
A top surface deformable portion provided on the top surface portion of each of the shock absorbing protrusions, and deformed when the shock absorbing protrusions are crushed and deformed;
The gist of the invention is that it includes a side surface deformation allowing portion that is provided on the outer peripheral side surface portion of each of the shock absorbing protrusion portions and allows deformation of the outer peripheral side surface portion when the shock absorbing protrusion portion undergoes crushing deformation.

  Therefore, according to the first aspect of the present invention, the overall shape can be maintained and the posture of each shock absorbing protrusion can be maintained by the planar connecting portions existing between the shock absorbing protrusions. Then, by providing the top surface easily deformable portion on the top surface portion of each shock absorbing protrusion and the side surface deformation allowing portion on the outer peripheral side surface portion, a crushing stroke when an external force is applied to the shock absorbing protrusion portion to cause the crush deformation A sufficient amount can be secured.

According to a second aspect of the present invention, in the first aspect of the invention, the top surface easily deformable portion is located between a plurality of top surface openings that are adjacent to the outer edge of the top surface portion and formed intermittently. The gist of the invention is that it is composed of a plurality of top surface deformation ribs extending radially outward from the center of the top surface portion.
Therefore, according to the invention which concerns on Claim 2, the reduction | restoration deformation | transformation of a top surface part is expressed appropriately, and the crush stroke amount of a crush deformation protrusion can be ensured reliably.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the side surface deformation allowing portion is an intermediate portion of the outer peripheral side surface portion in the protruding direction of the shock absorbing protrusion portion or the top surface portion from the intermediate portion. The gist of the present invention is that it is composed of a plurality of side openings formed at a required interval in the circumferential direction of the outer peripheral side surface portion in a portion adjacent to the outer peripheral side portion.
Therefore, according to the invention which concerns on Claim 3, when an impact-absorbing protrusion deform | transforms crushed by external force, the deformation | transformation of the upper edge part in an outer peripheral side part is expressed suitably.

The gist of the invention of claim 4 is that, in the invention of claim 3, each side opening is formed at a position aligned with a center line passing through the center of each top face opening.
Therefore, according to the invention which concerns on Claim 5, the rigidity of the rib-shaped vertical wall part formed in the upper edge part of an outer peripheral side surface part is reduced, and the reduction | decrease in the amount of crush strokes by this upper edge part becoming bulky is prevented. it can.

The gist of the invention according to claim 5 is that, in the invention according to any one of claims 1 to 4, the foamed resin member having a required thickness is mounted for use.
Therefore, according to the invention which concerns on Claim 5, when these foamed resin members and the impact-absorbing member for vehicles are combined, it is suitable for mounting | wearing and using for example, the back side of a bonnet.

  According to the vehicle impact absorbing member of the present invention, since the posture of the impact absorbing projection can be maintained and the amount of crushing stroke can be secured efficiently, the deformation of the impact absorbing projection can be appropriately expressed. Thus, there is an advantage that the impact absorption performance can be suitably improved.

  Next, the impact absorbing member for a vehicle according to the present invention will be described below with reference to the accompanying drawings by giving a preferred embodiment.

  FIG. 1 is a partial perspective view of a vehicle impact absorbing member according to a preferred embodiment, and FIG. 2 is an enlarged perspective view of one of impact absorbing projections provided on the vehicle impact absorbing member. The vehicle impact absorbing member EA of the present embodiment is made of a synthetic resin such as polypropylene (PP) or the like, and has a generally uniform thickness of about 0.5 to 3.0 mm. Such a vehicle impact absorbing member EA is obtained by molding a sheet-shaped member or a plate-shaped member into a cup shape based on a known molding technique such as vacuum forming or pressure forming. In addition to the molding method described above, the vehicle impact absorbing member EA can be integrally molded from molten resin or powder resin using injection molding, powder slush molding technology, or the like.

  The vehicle impact absorbing member EA projects to one side (one side) of the resin material P and opens to the other side (the other side), in other words, a cone projecting to one side of the planar connecting portion 18 described later. A plurality of shock absorbing projections 10 having a trapezoidal cup shape are arranged with a predetermined interval therebetween. These shock absorbing protrusions 10 basically have the same shape and the same dimensions, and the thickness of each part is substantially the same. For example, the diameter D1 of the skirt portion 14 in the outer peripheral side surface portion 12 is 40 mm, and the diameter of the top surface portion 16 D2 = 25 mm and protrusion height H = about 15 mm. Further, the interval S between each shock absorbing protrusion 10 adjacent to the periphery is set to about 100 mm. For example, when the vehicle impact absorbing member EA is disposed on the back surface of the bonnet of the body and is provided for implementation, the interval S is set in consideration of the case where the head of the pedestrian collides with the bonnet. It has been done.

  And the part between each impact-absorbing protrusion 10, ie, the non-existing part of each impact-absorbing protrusion 10, is located in the state in which the non-deformation part in the resin material P remains as it is. It is the planar connection part 18 which connects and hold | maintains an attitude | position. That is, in the vehicle impact absorbing member EA of the present embodiment, the planar connecting portions 18 exist around the entire periphery of each impact absorbing protrusion 10, and the skirt portion 14 of these impact absorbing protruding portions 10 is connected to the planar connection. Since the joint 18 is supported by the portion 18, even if an external force is partially applied to the top surface portion 16 of the shock absorbing projection 10, it is restricted that the shock absorbing projection 10 is independently displaced in posture. It has a structure. Moreover, since some bending deformation is expressed in the planar connecting portion 18 itself, the vehicle impact absorbing member EA is slightly bent as a whole, but local deformation such as partial bending is less likely to occur. The necessary and sufficient shape retention is ensured.

  As shown in FIG. 2 and FIG. 4 and the like, the top surface portion 16 of each shock absorbing projection 10 is allowed to be reduced in deformation when the shock absorbing projection 10 is crushed. A top surface deformable portion 40 is provided. The top surface easily deformable portion 40 has a plurality (six in this embodiment) located between a plurality (six in this embodiment) of top surface openings 42 formed intermittently adjacent to the outer edge of the top surface portion 16. The top surface deformation ribs 43 are formed. Each top surface deformation rib 43 has a length S and a width W set by the opening size and shape of the top surface opening 42, and extends radially outward from the center of the top surface portion 16. . Specifically, the top surface deformation rib 43 has a length S of about 4.0 mm and a width W of about 2.5 mm, and each of the top surface deformation ribs 43 is folded when an external force is applied to the shock absorbing projection 10. By bending or curving, the upper edge portion 12A of the outer peripheral side surface portion 12 is allowed to deform inward, and the amount of crushing stroke at the time of crushing deformation is increased.

  Further, the outer peripheral side surface portion 12 of each shock absorbing projection 10 is allowed to deform when the shock absorbing projection 10 is crushed and deformed as illustrated in FIGS. A side surface deformation allowing portion 30 is provided. The side surface deformation allowing portion 30 is arranged at a predetermined interval in the circumferential direction of the outer peripheral side surface portion 12 on the outer peripheral center line L2 passing through a substantially intermediate portion of the outer peripheral side surface portion 12 in the projecting direction (vertical direction) of the shock absorbing protrusion 10. The plurality of (six in the present embodiment) side openings 32 are formed. In addition, as illustrated in FIG. 4, each side surface opening 32 is formed at each position aligned with the opening center line L1 passing through the center in the longitudinal direction of each top surface opening 42 extending in the circumferential direction. It has a circular shape with a diameter of about 2 to 8 mm.

  The side surface deformation allowing portion 30 composed of the side surface opening 32 has a peripheral length difference of the outer peripheral side surface portion 12 when an external force is applied to the top surface portion 16 from above and the shock absorbing projection portion 10 is crushed. It is possible to reduce the rigidity of the rib-like vertical wall portion 46 (FIG. 6) formed by the loosening of the upper edge portion 12A that is likely to occur due to the above, and at the time of crushing deformation due to the bulkiness of the upper edge portion 12A This is to prevent a disadvantage that the amount of crushing stroke is reduced.

  Accordingly, in the vehicle impact absorbing member EA of the present embodiment, the top surface easily deformable portion 40 composed of a plurality of top surface deforming ribs 43 is formed by forming the top surface opening 42 in the top surface portion 16 of each shock absorbing protrusion 10. In addition, a side surface deformation allowing portion 30 including a side surface opening 32 is provided on the outer peripheral side surface portion 12 of each shock absorbing protrusion 10. For this reason, when an external force is applied to each shock absorbing protrusion 10 from above, the top surface easy-to-deform portion 40 and the side surface deformation allowing portion 30 function at the same time. The inconvenience inherent in each type of cup-shaped body 60 is appropriately eliminated to realize both the expansion of the crushing stroke amount and the increase of the shock absorption amount, and the excellent shock absorption performance can be exhibited.

  The shock absorbing protrusion 10 in the vehicle shock absorbing member EA configured as described above is configured such that when an external force accompanied by an impact force is applied, as illustrated in FIGS. Each top surface deformation rib 43 is bent and deformed while the top surface portion 16 sinks downward, while the top edge portion 12A of the outer peripheral side surface portion 12 approaches the top of the sinking top surface portion 16. It goes up. When the upper edge portion 12A is pushed upward above the top surface portion 16, a portion corresponding to the middle portion of each top surface opening 42 is slackened, and this portion is pushed downward to form a rib-like vertical wall portion. It tends to be 46. However, in the shock absorbing projection 10 of this embodiment, as described above, the side openings 32 are formed in the outer peripheral side face 12 so as to be aligned with the top face openings 42. The rigidity of the vertical wall portion 46 can be accurately reduced. In other words, each side opening 32 is formed in the upper edge portion 12A of the outer peripheral side surface portion 12 at a position matching the portion where the rib-like vertical wall portion 46 is easily formed. The rigidity of the lowers.

  Accordingly, each impact absorbing projection 10 constituting the vehicle impact absorbing member EA of the present embodiment is crushed by the upper edge portion 12A of the outer peripheral side surface portion 12 that is pushed up by the top surface portion 16 in the process of being crushed by an external force. Since the rigidity of the rib-like vertical wall portion 46 that causes a reduction in the stroke amount becomes low, as shown in FIG. 5, the crushing is relatively close to the protrusion height H (15 mm) when the crushing deformation is maximized. Stroke amount is secured. For this reason, an effective crushing stroke amount is ensured, and the bottoming phenomenon does not occur at an early stage during the crushing deformation, so that the amount of shock absorption is increased and efficient shock absorption is achieved. become.

  Next, the results of experiments conducted by the inventor of the present application regarding the impact absorption performance in the presence or absence of the top surface easily deformable portion 40 and the impact absorption performance when both the top surface easily deformable portion 40 and the side surface deformation allowing portion 30 are provided. Based on the explanation.

(Experiment 1)
First, as illustrated in FIG. 7, as illustrated in FIG. 7, the shock absorbing protrusions 10 have the same size, formation position, thickness, and the like, the same material, and the top surface portion 16 is provided with a top surface deformable portion 40. Vehicle shock absorbing member (FIG. 7A; sample S1 (Comparative Example 1)) and a vehicle shock absorbing member (FIG. 7B having an opening 44 in which the entire top surface portion 16 is completely opened). ); Sample S2 (Comparative Example 2)) and a vehicle shock absorbing member (FIG. 7 (c); Sample S3) provided with a top surface deformable portion 40 on the top surface portion 16 are prepared. The experiment was conducted. Here, as described above, the top surface easily deformable portion 40 in the sample S3 is composed of six top surface deforming ribs 43 extending radially from the center of the top surface portion 16 radially outward at equal intervals. The dimensions of the top surface deformation ribs 43 are length S = 4.0 mm and width W = 2.5 mm.

  FIG. 8 is a graph displaying the experimental results of the impact absorption performance of Samples S1 to S3. Although the sample S1 which is the comparative example 1 is set to the projection height H = 15 mm of each shock absorbing projection 10 as indicated by a two-dot chain line in the graph of FIG. The substantial crush stroke amount below the value is only about 4 mm, and since it becomes a bottomed state at this point, it can be confirmed that the load increases at a stroke thereafter. This means that since the top surface deformable portion 40 is not provided in particular, it is difficult to reduce the top surface portion 16 in a reduced manner. As in the crushing deformation state illustrated in FIG. It is because it will be folded over and it will become a rib shape and will invite a bottomed state at an early stage.

  In the sample S2 which is the comparative example 2, the crush stroke amount at the time of crushing deformation below the allowable maximum load value was about 11.5 mm. That is, it can be confirmed that the crush stroke amount of the sample S2 in which the top surface portion is the opening 44 is increased by about 7.5 mm as compared with the sample S1 in which the top surface portion 16 is a complete wall. However, it is possible to confirm the tendency of the crushing deformation of the shock absorbing protrusion 10 to easily proceed in a state where there is very little rise in the load in the entire crushing deformation and there is no so-called waist. This can be presumed to be because a contractive deformation of the completely open top surface portion is easily manifested.

  On the other hand, in sample S3, the amount of crushing stroke at the time of crushing deformation below the allowable maximum load value was about 10.5 mm. That is, the sample S3 provided with the top surface easily deformable portion 40 on the top surface portion 16 has a crush stroke amount increased by about 6.5 mm as compared with the sample S1 in which the top surface portion 16 is a complete wall, and the top surface portion is completely It can be confirmed that the crushing stroke amount is reduced by about 1 mm as compared with the sample S2 opened in the area. In addition, the rise of the load in the overall crushing deformation is considerably better than that of the sample S2, and the shock absorption amount indicated by hatching (area) is about 2.5 times that of the sample S1 and about twice that of the sample S2. Therefore, it can be confirmed that the shock absorbing performance is greatly improved.

  In other words, providing the top surface deformable portion 40 including the plurality of top surface deforming ribs 43 on the top surface portion 16 can greatly increase the crush stroke amount of the shock absorbing protrusion 10 when compared with the sample S1. The amount of shock absorption can be increased more than twice. Further, when compared with the sample S2, although the crushing stroke amount of the shock absorbing protrusion 10 is slightly reduced, the shock absorbing amount can be increased up to about twice. Therefore, providing the top surface easily deformable portion 40 on the top surface portion 16 is extremely effective in coexistence of the expansion of the crush stroke amount and the increase of the shock absorption amount at the time of the crush deformation of the shock absorbing protrusion 10. Was confirmed.

(Experiment 2)
Next, as illustrated in FIG. 9, as illustrated in FIG. 9, on the premise that the top surface deformable portion 40 identical to the sample S <b> 3 of Experiment 1 is provided on the top surface portion 16, the side surface deformation allowing portion 30 is further provided on the outer peripheral side surface portion 12. Two types of shock absorbing members for vehicles (FIG. 9A; sample S4 and FIG. 9B; sample S5) provided with the above were prepared, and an experiment for confirming the difference in shock absorbing performance was conducted. . Here, the side surface deformation allowing portion 30 in the sample S4 is configured by the side surface opening 32 formed at each position aligned with the center line passing through the center of each top surface deformation rib 43, and the side surface deformation allowing portion in the sample S5. 30 is the same as that illustrated in FIG. 4, and includes side openings 32 formed at positions that match the opening center line L <b> 1 passing through the center of each top opening 42. The side opening 32 formed in the sample S4 and the sample S5 has a circular shape with a diameter of 5 mm.

  FIG. 10 is a graph displaying the experimental results of the shock absorbing performance of the samples S4 and S5 and the above-described sample S3 (the side deformation allowing portion 30 is not provided). Sample S4 had a crush stroke amount of about 11.0 mm at the time of crushing deformation below the allowable maximum load value, as indicated by a broken line in FIG. That is, the sample S4 provided with the side surface deformation allowance portion 30 constituted by the side surface opening 32 formed so as to be aligned with the top surface deformation rib 43 has a crush stroke amount as compared with the sample S3 that does not have the side surface deformation allowance portion 30. Is an increase of about 0.5 mm, and an increase in the amount of crushing stroke can be confirmed. In addition, the degree of load rise in the initial stage of crushing deformation is substantially the same, and although the load is slightly lower in the middle stage of crushing deformation, the amount of shock absorption indicated by the area is increased because the crushing stroke amount is increased. The total amount is increased somewhat, and it can be confirmed that the crushing stroke amount is increased and the impact absorption amount is increased due to the provision of the side surface deformation allowing portion 30.

  On the other hand, in the sample S5 provided with the side surface deformation allowing portion 30 constituted by the side surface opening 32 formed so as to be aligned with the center of the top surface opening 42, the amount of crushing stroke at the time of crushing deformation below the maximum allowable load value is approximately. It was 12.0 mm. That is, the crush stroke amount of the sample S5 is increased by about 1.5 mm compared to the sample S3 that does not have the side surface deformation allowable portion 30, and compared with the sample S4 that has the side surface deformation allowable portion 30 of another mode. However, an increase of about 1 mm was confirmed. Moreover, although the degree of load rise in the initial stage of crushing deformation is slightly inferior to that of sample S3 and sample S4, in the intermediate stage of crushing deformation, the load greatly increases below the maximum allowable load, and the amount of crushing stroke also increases. Therefore, the total amount of shock absorption indicated by the area is considerably larger than that of the sample S3 and the sample S4, and the effects of the expansion of the crush stroke amount and the increase of the shock absorption amount due to the provision of the side surface deformation allowing portion 30 are provided. Can be confirmed sufficiently.

  From this, it has been confirmed that the provision of the side surface deformation allowing portion 30 on the outer peripheral side surface portion 12 is effective for increasing the crush stroke amount and increasing the shock absorption amount. And when providing the side surface deformation | transformation permission part 30 in the outer peripheral side surface part 12, forming the side surface opening 32 which comprises this in alignment with the center of the top surface opening 42 enlarges a crushing stroke amount and shock absorption amount. It was confirmed that it was extremely effective in achieving both increases. As described above, it is possible to provide each side opening 32 of the side deformation allowing portion 30 so as to be aligned with a portion where the rib-like vertical wall portion 46 is easily formed in the upper edge portion 12A of the outer peripheral side surface portion 12. It can be said that it has proved effective in reducing the rigidity of the vertical wall portion 46.

  And like the vehicle impact absorbing member EA of the present embodiment, the top surface deformable portion 40 composed of a plurality of top surface deformation ribs 43 is provided on the top surface portion 16 and the side surface deformation allowing portion composed of a plurality of side surface openings 32. 30 is provided on the outer peripheral side surface portion 12, compared with the sample S1 and sample S2 described above, that is, the conventional shock absorber EA1 disclosed in Patent Document 1, the crushing stroke amount is greatly increased and the shock absorption amount is greatly increased. It has been confirmed that it is possible to achieve both increases.

  The vehicle impact absorbing member EA of the present embodiment configured as described above is attached to the inside of the body in a state where the top surface portion 16 of each impact absorbing projection 10 is directed to the back side of the steel plate of the body. Provided for implementation. When a shocking external force is applied to the body from the outside, and the body is deformed inwardly, the above-described shock absorbing protrusion is crushed and deformed. Shock is absorbed.

  Further, as illustrated in FIG. 12A, the vehicle impact absorbing member EA of the present embodiment can be used by being mounted on one side of a foamed resin member 50 having a required thickness. At this time, as illustrated in FIG. 12B, when the shock absorbing protrusions 10 are mounted so that the protruding side of each shock absorbing protrusion 10 faces the foamed resin member 50, the shock absorbing protrusions 10 are formed of the foamed resin member. Since it enters with the compression deformation of 50, even if both members EA, 50 are combined, there is almost no increase in thickness. Since the foamed resin member 50 described above is used as a sound absorbing member that exhibits a sound absorbing function, when the foamed resin member 50 and the vehicle impact absorbing member EA are combined, for example, a hood It is suitable for use on the back side. Note that the combination of the vehicle impact absorbing member EA and the foamed resin member 50 is opposite to that shown in FIG. 12A, that is, the side where each impact absorbing projection 10 does not project is directed to the foamed resin member 50. May be.

  In addition, since the top surface portion 16 of the shock absorbing protrusion 10 is provided with a plurality of top surface openings 42 and the outer peripheral side surface portion 12 is provided with a plurality of side surface openings 32, the foamed resin member 50 having a sound absorbing function is provided. Since the top surface opening 42 and the side surface opening 32 are faced, the sound generated on the engine side is easily absorbed by the foamed resin member 50 facing the top surface opening 42 and the side surface opening 32.

  In addition, each side surface opening 32 of the side surface deformation | transformation permission part 30 is not limited only to what is formed in the intermediate part of the outer peripheral side surface part 12 as mentioned above, For example, as illustrated to Fig.11 (a), You may make it form in the upper edge part 12A side from the intermediate part (outer periphery centerline L2) of the outer peripheral side part 12, ie, the position close | similar to the top surface part 16. Moreover, each side surface opening 32 of the side surface deformation | transformation permission part 30 should just be formed in the position which aligns with the opening centerline L1 passing through the center of each top surface opening 42, More preferably, it passes the center of each top surface opening 42. It is good to form for every position aligned with the opening center line L1. In addition, as illustrated in FIG. 11B, the number may be further increased in a portion other than the opening center line L1. Further, the shape of each side opening 32 is not limited to the circular shape described above, and may be a slit-like long hole shape as exemplified in FIG.

  The form of the top surface easily deformable portion 40 is not limited to that of the above-described embodiment, and the shape and size of the top surface deforming rib 43 can be changed by changing the shape and number of the top surface openings 42. The number can be changed. Accordingly, the number of side openings 32 constituting the side deformation allowing portion 40 is not limited to six in the above-described embodiment, and is appropriately determined according to the number of top face openings 42 formed. Be changed.

  In the vehicle impact absorbing member EA of the above-described embodiment, the case where the top surface easily deformable portions 40 are provided in all the impact absorbing projections 10 is illustrated. However, since the allowable maximum load value that satisfies the HIC value differs depending on the location of the body where the vehicle impact absorbing member EA is disposed, for example, the top surface easily deformable portion 40 is included only in some of the impact absorbing projections 10. And the shock absorbing protrusion 10 provided with the top surface deformable portion 40 and the side surface deformable portion 30, and the shock absorbing protrusion without the top surface deformable portion 40 and the side surface deformable portion 30. The impact absorbing performance may be different for each part by mixing the part 10.

  Further, since the above-described vehicle impact absorbing member EA of the present embodiment is formed by vacuum forming or pressure forming from a sheet-like resin material P having a required thickness, basically, each of the impact absorbing protrusions 10 and the planar shape are formed. The connecting portion 18 has substantially the same thickness. However, in the case of the vehicle impact absorbing member EA manufactured by the above-described injection molding or powder slush molding or the like, (1) the thickness of each impact absorbing projection 10 and the planar connecting portion 18 is set to be different. (2) Each shock absorbing protrusion 10 is set to have a different thickness. (3) The thickness of each shock absorbing protrusion 10 is changed for each part (for example, the outer peripheral side surface portion 12 and the top surface portion 16). Is possible.

  The impact absorbing member for a vehicle according to the present invention is formed of a synthetic resin, and is disposed on the back side of a bonnet or a fender in a vehicle body so as to reduce the injury of a pedestrian who collides with the bonnet or the like. The present invention can be suitably implemented as a vehicle shock absorbing member.

1 is a partial perspective view of a vehicle impact absorbing member according to a preferred embodiment of the present invention. The perspective view which expanded and displayed the shock-absorbing protrusion. III-III sectional view taken on the line of FIG. It is a top view of an impact-absorbing protrusion, Comprising: The state before crushing deformation is shown. VV sectional view taken on the line of FIG. It is a top view of an impact-absorbing protrusion, Comprising: The state which carried out the crush deformation completely is shown. (a) is a partial perspective view illustrating the shock absorbing protrusion of the sample S1 as Comparative Example 1, (b) is a partial perspective view illustrating the shock absorbing protrusion of the Sample S2 as Comparative Example 2, (c) ) Is a partial perspective view illustrating the shock absorbing protrusion of the sample S3. The graph which displayed the experimental result of the shock absorption performance of sample S1-sample S3. (a) is the fragmentary perspective view which illustrated the shock absorption projection of sample S4, (b) is the partial perspective view which illustrated the shock absorption projection of sample S5. The graph which displayed the experimental result of the shock absorption performance of sample S4, sample S5, and sample S3. The partial top view of the impact-absorbing protrusion which showed the example of a change of a side surface deformation | transformation permission part. (a) is explanatory drawing which illustrated the case where the impact-absorbing member for vehicles of a present Example is mounted | worn with and used for a foamed resin member, (b) is sectional drawing of both members. The fragmentary perspective view of the buffer which is the conventional impact-absorbing member for vehicles. FIG. 14 is a sectional view taken along line ZZ in FIG. 13. Explanatory drawing which showed the problem which this cup-shaped body will carry out attitude | position displacement, when a partial external force is added to a cup-shaped body. Explanatory drawing which showed the inconvenience which the amount of crushing strokes reduces by an outer peripheral side part folding up, when a cup-shaped body carries out crush deformation.

Explanation of symbols

10 shock absorbing protrusions, 12 outer peripheral side parts, 16 top surface parts, 18 planar connection parts,
30 side deformation allowable part, 32 side opening, 40 top surface easy deformation part, 42 top surface opening,
43 Top surface deformation rib, 50 Foamed resin member

Claims (5)

A vehicle impact absorbing member made of synthetic resin,
A plurality of shock-absorbing protrusions (10) having a truncated cone shape arranged in a mutually spaced manner and having a cup shape;
A planar connecting portion (18) for connecting and supporting the skirt portion of each of the shock absorbing protrusions (10);
Provided on the top surface portion (16) of each of the shock absorbing protrusions (10), a top surface easily deformable portion (40) that deforms when the shock absorbing protrusion (10) undergoes crushing deformation, and
Side deformation allowing portion provided on the outer peripheral side surface portion (12) of each of the shock absorbing protrusion portions (10) and allowing deformation of the outer peripheral side surface portion (12) when the shock absorbing protrusion portion (10) undergoes crush deformation. (30) A vehicle impact absorbing member, comprising:   The top surface easily deformable portion (40) is located between a plurality of top surface openings (42) adjacent to the outer edge of the top surface portion (16) and formed intermittently, and the center of the top surface portion (16). The shock absorbing member for a vehicle according to claim 1, comprising a plurality of top surface deforming ribs (43) extending radially outward from a radial direction.   The side surface deformation allowing portion (30) is an outer peripheral side portion of the outer peripheral side surface portion (12) in the protruding direction of the shock absorbing protrusion (10) or a portion closer to the top surface portion (16) than the intermediate portion. The impact absorbing member for a vehicle according to claim 1 or 2, comprising a plurality of side openings (32) formed at required intervals in the circumferential direction of the side surface (12).   4. The vehicle impact absorbing member according to claim 3, wherein each side opening (32) is formed at a position aligned with a center line passing through a center of each top opening (42). The impact absorbing member for a vehicle according to any one of claims 1 to 4, wherein the impact absorbing member for a vehicle according to any one of claims 1 to 4 is used by being mounted on a foamed resin member (50) having a required thickness.

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