JP4597832B2 - Shock absorbing member for vehicle - Google Patents

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 the case of 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 absorb the impact efficiently and effectively. There is a need for improved performance. For example, FIG. 14 and FIG. 15 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 cup-like body 60 is arranged at regular intervals so that the hollow cores are parallel to each other. 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 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 undergoes crushing deformation, and the outer peripheral side surface portion 62 is expanded. Open deformation may be restricted. For this reason, as illustrated in FIG. 17, the cup-shaped body 60 is bent and deformed so that the outer peripheral side surface portion 62 is folded, and therefore, the cup-shaped body 60 is allowed to be deformed only to about half of the protrusion height H before the deformation. Therefore, a crushing stroke amount equivalent to the protruding height H cannot be obtained. That is, since a bottomed state occurs early in the middle of crushing deformation, the amount of shock absorption is reduced accordingly, and there is a problem that suitable shock absorption cannot be expressed.

  Accordingly, an object of the present invention is to provide a vehicle impact absorbing member having improved impact absorbing performance by securing a crush stroke amount at the time of crushing deformation.

In order to solve the problem and achieve the intended object, the invention according to claim 1
A vehicle impact absorbing member made of synthetic resin,
A plurality of shock-absorbing protrusions having a truncated cone shape arranged at predetermined intervals from each other;
Located in the absence portion of the front Ki衝 hammer absorbing projections, a planar connecting part the foot is connected and supported these shock absorbing projections,
Provided in the planar connecting portion at the outer peripheral portion of each shock absorbing protrusion, and when the shock absorbing protrusion is crushed and deformed, the outer peripheral side surface of the shock absorbing protrusion is allowed to deform outward. Ri Do and a crush deformation allowing portion,
The gist of the crushing deformation allowing portion is composed of a plurality of slits extending intermittently along one or more circles centered on the shock absorbing protrusion .

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, with each shock absorbing protrusion supported by the planar connecting portion, an external force is applied to the shock absorbing protrusion by providing a crushing deformation allowing portion on the outer peripheral portion of the shock absorbing protrusion. The amount of crushing stroke when crushing and deforming can be ensured. In addition, since the crushing deformation allowing portion is composed of a slit formed along the circumference of a circle centering on the shock absorbing protrusion, an appropriate space is defined around the shock absorbing protruding portion. The stroke amount can be secured reliably.

According to a second aspect of the present invention, in the first aspect of the invention, the slits extending along a plurality of circles and adjacent to inside and outside are formed so as to be offset in the circumferential direction. Is the gist.
Therefore, according to the invention which concerns on Claim 2 , while being able to efficiently expand the crush stroke amount of an impact-absorbing protrusion, the attitude | position holding | maintenance of this shock-absorbing protrusion can be aimed at.

The invention of claim 3 is the invention of claim 1 or 2, wherein the foot portion of each shock absorbing projections, a gist that the flange portion out collision along its outer periphery is extended To do.
Therefore, according to the invention according to claim 3 , the rigidity reduction of the shock absorbing projection due to the provision of the crush deformation allowable portion on the outer peripheral portion of the shock absorbing projection, and the reduction in the shock absorbing performance associated therewith, It is possible to prevent suitably. In particular, it functions suitably for improving the impact absorbing performance in the initial stage during crushing deformation.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein each of the shock absorbing protrusions has a cup shape protruding toward one side of the planar connecting part. The gist.
Therefore, according to the fourth aspect of the present invention, when an external force is applied to the impact absorbing projection, the impact can be absorbed by appropriately crushing and deforming.

The gist of the invention according to claim 5 is that, in the invention according to any one of claims 1 to 4 , it is used by being mounted on a foamed resin member having a required thickness.
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 shock absorbing member for a vehicle according to the present invention, the posture of the shock absorbing protrusion can be maintained and the amount of crushing stroke can be secured. There is an advantage that the 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 1 to 2 mm. Such a vehicle impact absorbing member EA is a resin material preformed as a sheet-like member or a plate-like member having the same outer size and thickness based on a known molding technique such as vacuum forming or pressure forming. P is formed by 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.

  Such a vehicle impact absorbing member EA protrudes to one side (one side) of the resin material P and opens to the other side (the other side), in other words, protrudes to one side of a planar connecting portion 18 described later. A plurality of frustoconical shock absorbing projections 10 having a cup shape are arranged at a predetermined interval from each other. 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 distance L 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 body bonnet or the like, the distance L 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 shock-absorbing protrusion 10, ie, the non-existing part of each shock-absorbing protrusion 10, has the non-deformation part in resin material P as it is, and while connecting these shock-absorbing protrusions 10, The planar connecting portion 18 that holds the posture is used. 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 portions of these impact absorbing protruding portions 10 are the planar connecting portions. 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. Further, since some flexural deformation appears in the planar connecting portion 18, the vehicle impact absorbing member EA is slightly bent as a whole, but local deformation such as partial bending is less likely to occur, It has necessary and sufficient shape retention.

  Further, as illustrated in FIG. 4, a crushing deformation allowing portion 20 is provided on the planar connecting portion 18 in the outer peripheral portion of each shock absorbing protrusion 10. The crushing deformation allowing portion 20 is a space provided around the shock absorbing projection 10, and when the shock absorbing projection 10 is crushed and deformed by an external force, the outer peripheral side surface portion 12 expands outward. This is to allow deformation, and is intended to increase the amount of crushing stroke during crushing deformation so that the outer peripheral side surface portion 12 does not overlap. Such a crushing deformation allowing portion 20 is composed of a plurality of slits 22 and 26 extending intermittently along a double concentric circle with the corresponding shock absorbing projection 10 as the center. Then, by appropriately setting the widths of all the slits 22 and 26, the crushing-deformed impact absorbing projections 10 are allowed to be crushed flat without being bulky.

  Among these, a total of three first slits 22 are provided on the outer side of the shock absorbing protrusion 10, that is, on the circumference of the inner circle, and the first slit 22 is provided between the end portions of the first slits 22. A continuous portion 24 is formed. Here, the width R1 of each first slit 22 is set to about 5 mm, and the width T1 of each first connecting portion 24 is set to about 7 mm. Further, a total of three second slits 26 are extended on the circumference of the outer circle, and a second continuous portion 28 is formed between the end portions of each second slit 26. The width R2 of each second slit 26 is set to about 5 mm, and the width T2 of each second connecting portion 28 is set to about 7 mm. Further, the interval T3 between the first slit 22 and the second slit 26 is set to about 3 mm.

  And the 1st slit 22 and the 2nd slit 26 which adjoin inside and outside are formed so that it may be shifted in the circumference direction and located. That is, each of the second slits 26 is biased in the circumferential direction by approximately ½ pitch (about ½ of the total length) with respect to the first slit 22, and each of the first connecting portions 24 is in the first direction. The second continuous portion 28 is located adjacent to the substantially central portion of the first slit 22 and is located adjacent to the substantially central portion of the two slits 26. Thereby, since the 1st continuous connection part 24 and the 2nd continuous connection part 28 are not matched, the expansion deformation | transformation of the outer peripheral side surface part 12 is not inhibited at the time of the crush deformation of the impact-absorbing protrusion 10, as mentioned later. Has been taken into account.

  However, the crushing deformation allowing portion 20 is composed of a plurality of slits that extend in a single and intermittent manner along one circle centered on the shock absorbing protrusion 10, or the shock absorbing protruding portion 10 as the center. It may be constituted by a plurality of rows of slits extending intermittently along a triple or more circle.

  And the collar part 30 which protruded in the required width along the outer periphery is extended in the skirt part 14 of the outer peripheral side surface part 12 in each shock absorption protrusion 10. As shown in FIG. That is, the flange portion 30 is formed so as to face the first slit 22 by forming each of the first slits 22 described above at a position offset from the outer peripheral side surface portion 12 in the radial direction outward by a required amount. Is. The flange 30 has the above-described crush deformation allowing portion 20 (the first slit 22 and the second slit 26) formed on the outer peripheral portion of the shock absorbing protrusion 10, thereby reducing the rigidity of the shock absorbing protrusion 10. It functions to supplement the strength of the hem portion 14.

  That is, the shock absorbing protrusion 10 has a space formed along the outer periphery of the skirt portion 14 by forming the first slit 22 of the crushing deformation allowing portion 20, so that the outer peripheral side surface portion 12 can be applied only by applying a small external force. May be inadvertently deformed radially outward and / or radially inward, and the shock absorbing performance may not be sufficiently exhibited. Therefore, by providing the flange portion 30 along the outer periphery of the skirt portion 14, the strength of the outer peripheral side surface portion 12 can be appropriately increased, thereby restricting the expansive deformation of the outer peripheral side surface portion 12. it can. In addition, it is desirable to set the extending width G of the collar portion 30 within a range of 0.5 to 3 mm based on an experimental result described later.

  Next, the process of crushing deformation of the shock absorbing projection 10 in the vehicle shock absorbing member EA configured as described above will be described with reference to FIGS. As illustrated in FIG. 1, the vehicle impact absorbing member EA of the present embodiment has a large number of impact absorbing projections 10, and the skirt portion 14 of each impact absorbing projection 10 is connected by a planar connecting portion 18. ing. Further, as illustrated in FIGS. 3 and 4, a crushing deformation allowing portion 20 including a first slit 22 and a second slit 26 is provided on the outer peripheral portion of each shock absorbing protrusion 10. In addition, a collar portion 30 extends from the skirt portion 14 of each shock absorbing projection 10.

In such a vehicle impact absorbing member EA, when an impact is applied to the impact absorbing projection 10 from above in the state of FIGS. 3 and 4, first, as illustrated in FIGS. 5 and 6, the impact absorbing projection The skirt portions 14 of the outer peripheral side surface portions 10 are deformed so as to expand outward due to the presence of the crushing deformation allowing portion 20. Note that by the flange portion 30 in the foot 14 of the peripheral side face 12 is extended, never該裾unit content 14 is inadvertently deformed radially inwardly, the predetermined pressing force is applied Displaces radially outward. Then, as the pressing force is applied, the outer peripheral side surface portion 12 collapses while being deformed in an open manner, so that the top surface portion 16 is pushed from the entire periphery, so that the central portion is displaced downward and depressed. And deform in a reduced manner. Therefore, at the time of FIG. 5 and FIG. 6, the bottom is not yet developed.

  Further, when an external force is applied, as illustrated in FIGS. 7 and 8, the outer peripheral contour portion of the top surface portion 16 is reduced when the gaps between the first slits 22 and the second slits 26 are almost eliminated. Therefore, the upper edge portion of the outer peripheral side surface portion 12 is folded over the top surface portion 16. As a result, in the shock absorbing projection 10, the upper edge portion of the outer peripheral side surface portion 12 rises toward the top surface portion 16, and the outer peripheral side surface portion 12 and the top surface portion 16 are folded and loosened in the vicinity of the boundary portion. Depending on the case, as shown in FIG. 8, rib-like slack portions may be formed at a plurality of locations (six locations in the drawing) of the portion folded on the top surface portion 16. When such a folding phenomenon occurs, the loss of the effective crushing stroke amount may occur to some extent, but the outer peripheral side surface portion 12 itself is hardly bent at an appropriate site and is almost in a plane state. Since deformation occurs, when the crushing deformation is maximized, a crush stroke amount substantially close to the protrusion height H (15 mm) is ensured, and the shock absorption amount is increased so that the shock absorption is suitably achieved.

  In addition, the expansion deformation of the outer peripheral side surface portion 12 and the reduction deformation of the top surface portion 16 do not necessarily proceed with time with a time lag as described above, and these deformations may proceed simultaneously. . Thus, even if the expansion deformation of the outer peripheral side surface portion 12 and the reduction deformation of the top surface portion 16 proceed simultaneously, the outer peripheral side surface portion 12 itself hardly deforms so as to be folded. The absorption protrusion 10 can be crushed and deformed to a state close to a flat surface, and a sufficient amount of crushing stroke is ensured.

  Next, the difference in the impact absorption performance depending on the presence or absence of the crushing deformation allowing portion 20 will be described based on the experimental results conducted by the inventor of the present application. Moreover, it experimented also about the difference in the shock absorption performance by the difference in the aspect of the crushing deformation | transformation permission part 20. FIG. That is, as illustrated in FIG. 9, the impact absorbing projections 10 have the same size, formation position, thickness, etc. and the same material, and are not provided with the above-described crush deformation allowing portion 20. A member (FIG. 9 (a); sample S1) and an impact absorbing member for a vehicle (FIG. 9 (b); sample S2, FIG. 9 (c); sample S3) provided with a crushing deformation allowing portion 20; Each was tested for shock absorption performance. Here, the sample S2 is formed in such a manner that the first slit 22 and the second slit 26 constituting the crushing deformation allowing portion 20 are formed side by side, and the first connecting portion 24 and the second connecting portion 28 are aligned. is there. Further, the sample S3 is formed such that each of the first slit 22 and the second slit 26 is biased in the circumferential direction by ½ pitch, and the first connecting portion 24 and the second connecting portion 28 are not aligned. It is.

  The sample S1, which is a comparative example, has a permissible maximum load value despite the fact that the projection height H of each shock absorbing projection 10 is set to 15 mm, as indicated by the two-dot chain line in the graph of FIG. The substantial crush stroke amount in the following 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 crush deformation allowable portion 20 is not particularly provided, it is difficult for the outer peripheral side surface portion 12 to be expanded, and similarly to the crush deformation state illustrated in FIG. This is because they are bent and overlapped, leading to a bottomed state at an early stage.

  On the other hand, in sample S2, the crush stroke amount at the time of crushing deformation below the allowable maximum load value is about 11.5 mm, and in sample S3, the crush stroke amount at the crushing deformation below the allowable maximum load value is about 11.5 mm. It became 12.5 mm. That is, it can be confirmed that the sample S2 and the sample S3 provided with the crushing deformation allowing part 20 increased the crush stroke amount by 7 mm or more in any case as compared with the sample S1 not provided with the crushing deformation allowing part 20. From this, it has been confirmed that the provision of the crushing deformation allowing portion 20 is extremely effective in increasing the amount of crushing stroke at the time of the crushing deformation of the shock absorbing protrusion 10.

  In addition, regarding the difference in characteristics depending on the mode of the crushing deformation allowing portion 20, the crush stroke amount of the sample S3 which is the continuous portion non-alignment mode is larger than that of the sample S2 which is the continuous portion alignment mode. This is because, when the first connecting portion 24 and the second connecting portion 28 are aligned in a straight line, the shock absorbing protrusion is similar to the bridge 66 in the conventional buffer EA1 illustrated in FIGS. It can be inferred that when the outer peripheral side surface portion 12 is deformed in an expansive manner when the portion 10 is crushed, both the connecting portions 24 and 28 act like a so-called “support bar”. Therefore, when the crushing deformation allowing portion 20 is configured by a plurality of rows of slits 22 and 26, the slits 22 and 26 adjacent to the inside and outside are positioned so as to be appropriately shifted in the circumferential direction as in the sample S3. It has been confirmed that the crushing stroke amount can be increased more efficiently when the first connecting portion 24 and the second connecting portion 28 are not aligned.

  In the case of the sample S2 and the sample S3 provided with the crushing deformation allowing portion 20, the rising of the load is small in the whole crushing deformation, and the crushing deformation of the impact absorbing protrusion 10 tends to easily proceed. This is because the space due to the formation of the first slit 22 and the second slit 26 is present in the outer peripheral portion of the shock absorbing projection 10, so that the outer peripheral side surface portion 12 is easily deformed. Can be guessed. In other words, the provision of the crushing deformation allowing portion 20 works extremely effectively in terms of securing the crush stroke amount of the shock absorbing projection 10 and improving the shock absorbing performance. It can be said that there are some problems in that the impact absorbing performance at the initial stage of deformation is somewhat lowered. Therefore, when the crushing deformation allowing portion 20 is provided, it is possible to appropriately overcome this problem by forming the collar portion 30 described above.

  If the number of slits in the crushing deformation allowing portion 20 is further increased radially outward (three rows or more), an increase in the amount of crushing stroke can be expected by expanding the space. However, when the slits are extended radially outward in this way, the length of the continuous portion (including the first continuous portion 24 and the second continuous portion 28) becomes further longer, and FIG. Therefore, it can be estimated that there is a possibility that it is difficult to maintain the appropriate posture of each shock absorbing projection 10.

  FIG. 12 confirms the difference in the shock absorbing performance depending on the presence or absence of the above-described collar part 30 on the assumption that the above-described crush deformation allowing part 20 is provided, and as illustrated in FIG. 5 is a graph showing the results of an experiment conducted for confirming a difference in shock absorbing performance due to a difference in the protruding width G. In the actual experiment, the experiment was performed by changing the extension width G of the collar portion 30 from 0.1 to 4.0 mm every 0.1 mm. In the graph shown in FIG. Typical dimensions are extension width G = 0.3 mm (sample S4), extension width G = 0.5 mm (sample S5; FIG. 13A), extension width G = 3 mm (sample S6; FIG. 13). (b)), only the experimental results in the extension width G = 3.5 mm (sample S7) are displayed.

  In the case of the sample S4 in which the extending width G of the flange 30 is 0.3 mm, as shown by the broken line in the graph of FIG. 14, there is almost no difference from the above-described sample S3 in which the flange 30 is not provided, and the load The effect of providing the collar portion 30 is not manifested only by the slightly rising of the. Further, in the case of the sample S5 with the extension width G = 0.5 mm, it can be determined that there is an effect of increasing the load as indicated by a thin solid line in the graph. On the other hand, in the case of the sample S6 with the extension width G = 3.0 mm, it can be confirmed that the load rise at the initial stage of the crushing deformation is considerably good as indicated by the thick solid line in the graph. However, the amount of crushing stroke below the allowable maximum load value was about 11 mm, which was reduced by about 1 to 1.5 mm as compared with the case where the flange 30 was not provided. Furthermore, in the case of the sample S7 having an extension width G = 3.5 mm, even if the crushing deformation allowing portion 20 is provided as shown by a one-dot chain line in the graph, the outer peripheral side surface portion 12 is expanded and deformed. Therefore, the amount of crushing stroke below the allowable maximum load value is reduced to about 7 mm at a stroke.

  Therefore, the collar portion 30 is extremely useful in the sense of compensating for the rigidity reduction of the skirt portion 14 of the shock absorbing projection 10 that occurs when the above-described crush deformation allowable portion 20 is provided, and increases the load in the initial stage of crush deformation. It was confirmed that the effect was demonstrated. The effect of providing the crushing deformation allowing portion 20 is canceled out when the extension width G when the flange portion 30 is provided is 0.5 mm or less, and when it is 3.0 mm or more. Therefore, it can be said that it is desirable to set within the range of 0.5 to 3.0 mm.

  Here, the total amount of shock absorption accompanying the crushing deformation of the shock absorbing protrusion 10 corresponds to the area of the hatched display portion in the graph of FIG. Therefore, in the vehicle impact absorbing member EA of this embodiment, when an external force is applied, the load rises to some extent at the initial stage of the crushing deformation, and the crushing deformation proceeds to a stroke of about 11 mm below the allowable maximum load value. The area of the display portion is increased and the total shock absorption is increased. On the other hand, in the case of the sample S1, the rise of the load in the initial stage of the crushing deformation is much quicker, but the crushing stroke amount is extremely small. It is about 1/3 of the vehicle impact absorbing member EA. Therefore, it was confirmed that the impact absorbing performance for the vehicle impact absorbing member EA of the present example was suitably improved by providing the above-described crushing deformation allowing portion 20 and the flange portion 30.

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. 13A, 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. 13B, 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. 13A, that is, the side where the impact absorbing projections 10 do not project is directed to the foamed resin member 50. May be.

  According to the vehicle impact absorbing member EA of the present embodiment described above, the following operational effects are obtained. First, the vehicular shock absorbing member EA has a planar connecting portion 18 between the shock absorbing projections 10 so that the overall shape can be maintained and the posture of each shock absorbing projection 10 can be maintained. Preferably. Then, with the skirt portion 14 of each shock absorbing projection 10 supported by the planar connecting portion 18, by providing the crushing deformation allowing portion 20 on the outer peripheral portion of the shock absorbing projection 10, A sufficient amount of crushing stroke can be ensured when an external force is applied to the shock absorbing projection 10 to cause crushing deformation. Moreover, since each impact absorption protrusion 10 is exhibiting the cup shape which protruded to the one side of the planar connection part 18, when external force is added, it can crush and deform | transform appropriately and can absorb an impact suitably.

  Further, since the crushing deformation allowing portion 20 is composed of slits 22 and 26 formed along the circumferences of a plurality of inner and outer circles centering on the shock absorbing protrusion 10, the crush deformation allowing portion 20 is formed around the shock absorbing protrusion 10. Appropriate space is defined and the amount of crushing stroke can be ensured. In addition, the first slit 22 and the second slit 26 that are formed on the circumference of a concentric circle centering on the shock absorbing protrusion 10 and are adjacent to the inside and outside are formed so as to be shifted by about 1/2 pitch in the circumferential direction. As a result, the amount of crushing stroke of the shock absorbing projection 10 can be increased efficiently, and the posture of the shock absorbing projection 10 can be maintained.

  And by providing the crushing deformation allowing portion 20 on the outer peripheral portion of the shock absorbing projection 10 and extending the flange portion 30 along the skirt portion 14 of the outer peripheral side surface portion 12 of the shock absorbing projection 10, It is possible to preferably prevent the rigidity of the shock absorbing projection 10 from being lowered and the accompanying shock absorbing performance from being lowered due to the provision of the crushing deformation allowing portion 20. In particular, it functions suitably for improving the impact absorbing performance in the initial stage during crushing deformation. By setting the extending width G within the range of 0.5 to 3.0 mm, the flange 30 can achieve a good balance between the rigidity of the shock absorbing projection 10 and the shock absorbing performance.

  In the vehicle impact absorbing member EA of the above-described embodiment, the case where the crushing deformation allowing portion 20 and the flange portion 30 are provided on 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 on which the vehicle impact absorbing member EA is disposed, for example, (1) only the crushing deformation allowable portion 20 is provided, (2) crushing You may make it change as needed, such as providing both the deformation | transformation permission part 20 and the collar part 30. FIG. Further, in a single vehicle shock absorbing member EA, the shock absorbing protrusion 10 provided with only the crushing deformation allowing portion 20 and the shock absorbing protruding portion 10 provided with both the crushing deformation allowing portion 20 and the flange 30 are provided. In this case, it is possible to make the shock absorbing performance different for each part.

  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 middle of crushing deformation | transformation is shown. VII-VII 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 the fragmentary perspective view which illustrated the shock absorption projection of sample S1 which is the comparative example, (b) is the partial top view which illustrated the shock absorption projection of sample S2, (c) is sample S3 The partial top view which illustrated the shock absorption protrusion. The graph which displayed the experimental result of the shock absorption performance concerning sample S1-sample S3. (a) is the partial top view which illustrated the shock absorption protrusion of sample S5, (b) is the partial top view which illustrated the shock absorption protrusion of sample S6. The graph which displayed the experimental result of the shock absorption performance concerning sample S1 and sample S3-sample S7. (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. ZZ sectional drawing of FIG. 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 because an outer peripheral side part bends when a cup-shaped body is crushed and deformed.

Explanation of symbols

10 shock-absorbing protrusions, 14 hem parts, 18 planar connection parts, 20 crush deformation allowable parts,
22 1st slit, 26 2nd slit, 30 collar part, 50 foaming 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 at a necessary interval from each other;
Before located absence portion of Ki衝 hammer absorbing protrusion (10), the planar connecting portion for connecting supporting foot (14) of the shock absorbing protrusion (10) and (18),
Provided in the planar connecting portion (18) at the outer peripheral portion of each shock absorbing protrusion (10), and when the shock absorbing protrusion (10) is crushed and deformed, the outer periphery of the shock absorbing protrusion (10) Ri Do from the side portion (12) is crushed deformation allowing portion for allowing the deformation outward (20),
The crushing deformation allowing portion (20) is composed of a plurality of slits (22, 26) extending intermittently along one or more circles centered on the shock absorbing protrusion (10). A shock absorbing member for a vehicle characterized by the above. A plurality of extending along a circle with the slit adjacent to the inner and outer (22, 26) for a vehicle impact absorbing member according to claim 1 wherein formed to be positioned offset in the circumferential direction. The foot (14) of each shock absorbing protrusion (10), a vehicle impact absorbing member according to claim 1 or 2, wherein the flange portion that has issued collision along its outer peripheral edge (30) is extended. Each shock absorbing protrusion (10) for a vehicle impact absorbing member according to any one of claim 1 to 3, it exhibits the planar connecting portion (18) while projecting to the side cup-shaped. The impact-absorbing member for vehicles 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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