JP2010280309A - Impact absorbing structure for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact absorbing structure for a vehicle enhancing durability during the time when a load is applied and a complete compressive deformation occurs in an axial direction, while achieving high performance weight efficiency in terms of impact absorbing performance. <P>SOLUTION: The structure comprises an inner cylindrical body 2 and an outer tubular body 3. In the inner cylindrical body 2, vertical cross sections at positions separated oppositely in the axial direction by a predetermined distance from a predetermined position form a regular hexagon formed by rotating the regular hexagon located at the predetermined position approximately 30&deg; (180&deg;/6) around the axis; and lines connecting each side 21 to each apex 22 of each regular hexagon are used as a valley fold portion 23 or a crest fold portion 24 to form a substantially triangle plane portion 25A between the valley fold portion 23 and crest fold portion 24 regularly and continuously. The outer tubular body 3 has a cross-sectional shape circumscribed to each apex 22 of each regular hexagon of the inner cylindrical body 2 with inner spherical parts abutting on each apex 22 and connected, and cover the inner cylindrical body 2. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an impact absorbing structure for a vehicle that absorbs an impact by compressing and deforming in the axial direction when a load is received from one of the axial directions.

  2. Description of the Related Art Various types of shock absorbing structures that absorb shock generated by a vehicle collision or the like by compressive deformation in the axial direction have been proposed.

  For example, in Patent Document 1 described below, a shock absorbing member (distortion shell) that has a substantially bellows shape and can expand and contract in the axial direction when a load is applied from one axial direction, and cylindrical shapes on both the inner and outer sides thereof. A structure comprising a body (tension post) is disclosed.

  In this case, when a load is applied from one side in the axial direction, the above-described bellows-like impact absorbing member expands or contracts in accordance with the direction of the load, so that the impact can be absorbed.

  Further, in Patent Document 2 below, a vertical cross section when cut in a direction orthogonal to the axial direction at a predetermined position forms a regular n-gonal shape, and at each position away from the predetermined position on both sides in the predetermined axial direction. The vertical cross section is a regular n-gon obtained by rotating the regular n-gon at the predetermined position about 180 ° / n around the axis, and a line connecting each side and each top of each regular n-gon is valley-folded. As a part or a mountain fold part, a cylindrical structure in which a substantially triangular plane part is regularly and continuously formed between the valley fold part and the mountain fold part is disclosed.

  In the case of a structure having such a polyhedral structure, when a load is applied from one side in the axial direction by regularly and continuously arranging the plane portion as the smallest structural unit constituting the polyhedral structure, the structure The entire surface of the body can be crushed almost uniformly. For this reason, there exists an advantage that an impact can be absorbed more efficiently.

  In the following Patent Document 2, an experiment is conducted on the fact that a structure having a multi-face structure has higher shock absorption performance than a cylindrical body having no multi-face structure in which the width (diameter) in the direction orthogonal to the axial direction is set to be the same. It shows by.

  That is, by adopting the structure disclosed in Patent Document 2 below, it is possible to increase the numerical value obtained by dividing the impact energy absorption amount by the total weight of the structure, so-called performance weight efficiency. Can be achieved.

  In recent years, from the viewpoint of environmental protection, there has been an increasing demand for improvement in fuel consumption, and various research and developments have been made on weight reduction of vehicle bodies in order to achieve this. For these reasons, there is a need for a shock absorbing structure that is lighter and that exhibits high shock absorbing performance, and the above performance weight efficiency is extremely important in developing the shock absorbing structure. It has become an element.

JP 7-81509 A JP 2002-284032 A

  By the way, the impact absorption performance of a structure is generally evaluated by the amount of shock energy absorbed that can be absorbed by compressive deformation of the structure and the durability from when a load is applied until it completely compresses and deforms in the axial direction. The

  Here, looking at the structure disclosed in Patent Document 1, the inner and outer cylindrical bodies constituting the structure are welded only to the end portions of the shock absorbing member. In this case, when a load is applied in the axial direction of the structure, the inner and outer cylindrical bodies are only displaced in the axial direction relative to the shock absorbing member, and are not accompanied by compressive deformation.

  That is, in this case, the inner and outer cylindrical bodies do not contribute to shock absorption, and as a whole structure, only the shock absorbing member has a shock absorbing function. Therefore, since the structure disclosed in Patent Document 1 includes two cylindrical bodies in addition to the impact absorbing member, high impact absorbing performance cannot be obtained. Will be reduced.

  Furthermore, in the structure disclosed in Patent Document 1, since the inner and outer cylindrical bodies do not contribute to shock absorption as described above, the structure ( There is also a problem that the durability until the shock absorber member) is completely compressed and deformed cannot be sufficiently increased.

  On the other hand, the inventor conducted various analyzes and examinations on the shock absorbing performance of the structure disclosed in Patent Document 2. And as a result of earnest research, it certainly realizes improvement of performance weight efficiency, but because it has a polyhedral structure with unevenness in the axial direction, deformation in the axial direction is excessively promoted. It was found that the durability mentioned above was rather lowered.

  The present invention relates to shock absorbing performance, and provides a vehicle shock absorbing structure capable of enhancing durability from when a load is applied until it is completely compressed and deformed in the axial direction while realizing high performance and weight efficiency. For the purpose.

  In the vehicle impact absorbing structure according to the present invention, a vertical cross section when cut in a direction orthogonal to the axial direction at a predetermined position forms a regular n-gon (n ≧ 4), and a predetermined distance axial direction from the predetermined position. A vertical cross section at each position separated on both sides forms a regular n-gon obtained by rotating the regular n-gon at the predetermined position about 180 ° / n around the axis, and each side of each regular n-gon A line connecting each apex as a valley fold or a mountain fold, and between the valley fold and the mountain fold, an inner cylinder formed with a regular triangular plane part regularly and continuously, It has a cross-sectional shape that circumscribes each apex of each regular n-gon of the inner cylinder, and is composed of an outer cylinder that covers and joins the inner peripheries to the apexes. is there.

According to this structure, the load which acts from one side of an axial direction can be first received locally in each coupling | bond part and its periphery by cooperation with an inner cylinder body and an outer cylinder body. As a result, it is possible to improve durability from when the load is applied until the structure is completely compressed and deformed.
Furthermore, by joining the inner cylinder body and the outer cylinder body for each top, when the compressive deformation proceeds, both the inner cylinder body and the outer cylinder body can be deformed substantially uniformly in the axial direction and the circumferential direction. For this reason, substantially the whole structure contributes to shock absorption, and as a result, performance weight efficiency (impact energy absorption amount / total weight of structure) can be improved.

  In one embodiment of the present invention, the outer cylindrical body is a polygonal tube whose vertical cross section forms a regular 2n square, and the side of the regular 2n square of the outer cylindrical body and the top of the inner cylindrical body are This is consistent with the axial view.

  According to this structure, the top part of an inner cylinder and the inner peripheral part of the plane part of an outer cylinder can be made to contact | abut reliably, and both can be combined reliably.

  In the vehicle impact absorbing structure according to the present invention, the vertical cross section when cut in a direction orthogonal to the axial direction at a predetermined position forms a regular n-gon (n ≧ 4) and a predetermined distance from the predetermined position. A vertical cross section at each position apart on both sides in the axial direction forms a regular n-gon obtained by rotating the regular n-gon at the predetermined position about 180 ° / n around the axis, and each side of each regular n-gon An outer cylinder formed by regularly and continuously forming a substantially triangular plane portion between the valley fold portion and the mountain fold portion, with a line connecting the portion and each top portion as a valley fold portion or a mountain fold portion. And an inner cylindrical body having a cross-sectional shape inscribed in each side portion of each regular n-gon of the outer cylindrical body, an outer peripheral portion being in contact with and coupled to the respective side portions, and covered with the outer cylindrical body, It consists of

According to this structure, the load which acts from one side of an axial direction can be first received locally in each coupling | bond part and its periphery by cooperation with an inner cylinder body and an outer cylinder body. As a result, it is possible to improve durability from when the load is applied until the structure is completely compressed and deformed.
Furthermore, by joining the inner cylinder body and the outer cylinder body for each side portion, when the compressive deformation proceeds, both the inner cylinder body and the outer cylinder body can be deformed substantially uniformly in the axial direction and the circumferential direction. For this reason, substantially the whole structure contributes to shock absorption, and as a result, performance weight efficiency (impact energy absorption amount / total weight of structure) can be improved.

  In one embodiment of the present invention, the inner cylindrical body is a polygonal tube whose vertical cross section is a regular 2n square, and the regular 2n square side part of the inner cylindrical body, the side part of the outer cylindrical body, Are in agreement in the axial direction.

  According to this structure, the outer peripheral part of the plane part of an inner cylinder and the side part of an outer cylinder can be made to contact | abut reliably, and both can be combined reliably.

  In one embodiment of the present invention, the regular n-gon is a regular hexagon (n = 6), and the planar portion of a substantially isosceles triangle is regularly arranged between the valley fold and the mountain fold. And it is formed continuously.

  According to this configuration, the polygonal tube can have a regular dodecagonal cross section in the vertical direction, and the durability against load in the polygonal tube can be improved to the maximum.

  In one embodiment of the present invention, the outer cylinder body and the inner cylinder body are tapered so that the width in the direction orthogonal to the axial direction is narrowed toward one side in the axial direction.

According to this configuration, when the inner cylinder is inserted into the outer cylinder at the time of manufacturing the structure, the insertion process is performed by inserting the inner cylinder from the widened side of the outer cylinder. The work in can be facilitated.
Moreover, when the load is applied to the structure in the axial direction by the widened sides of the inner cylinder and the outer cylinder, the structure can be prevented from falling in a direction orthogonal to the axial direction.

According to the present invention, the load acting from one side in the axial direction can be first received locally at each coupling portion and its periphery by the cooperation of the inner cylinder body and the outer cylinder body. Then, the durability until the structure is completely compressed and deformed can be improved.
Furthermore, by joining the inner cylinder and the outer cylinder for each top, when compression deformation proceeds, both the inner cylinder and the outer cylinder can be deformed substantially equally in the axial direction and the circumferential direction. As a result, performance weight efficiency can be improved.

The perspective view which shows the shock absorption structure for vehicles which concerns on embodiment of this invention. (A) A perspective view of the inner cylinder constituting the shock absorbing structure for a vehicle in FIG. 1, (b) a perspective view of the outer cylinder, (c) a state in which the outer cylinder and the inner cylinder are combined, The figure which showed the outer cylinder body in the permeation | transmission state. The top view of the shock absorption structure for vehicles. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3. It is a figure which shows the result of having carried out the simulation analysis by CAE about the behavior at the time of applying a load from one side of an axial direction to the shock absorption structure for vehicles shown in Drawing 1, and shows the state before adding (a) compression load. 4 is a cross-sectional view corresponding to FIG. 4, (b) a cross-sectional view corresponding to FIG. 4 showing a state immediately after the compression load is applied, and (c) equivalent to FIG. 4 showing a state when a compression load is further applied from the state of (b). FIG. The perspective view which shows the shock absorption structure for vehicles which concerns on other embodiment of this invention. (A) A perspective view of an outer cylinder constituting the shock absorbing structure for a vehicle of FIG. 6, (b) a perspective view of the inner cylinder, (c) a state in which the outer cylinder and the inner cylinder are combined, The figure which showed the outer cylinder body in the permeation | transmission state. The top view of the shock absorption structure for vehicles. FIG. 9 is a sectional view taken along line B-B in FIG. 8. Sectional drawing which shows the impact-absorbing structure for vehicles which concerns on further another embodiment of this invention. Sectional drawing which shows the impact-absorbing structure for vehicles which concerns on further another embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing a vehicle shock absorbing structure according to the present embodiment, and FIG. 2A is a perspective view of an inner cylinder constituting the vehicle shock absorbing structure of FIG. FIG. 2B is a perspective view of the outer cylindrical body, and FIG. 2C is a view showing a state in which the outer cylindrical body and the inner cylindrical body are coupled with the outer cylindrical body being in a transparent state. As shown in FIGS. 1 and 2, a shock absorbing structure for a vehicle (hereinafter simply referred to as a structure) 1 is an inner cylindrical body having a multi-face structure in which irregularities are regularly arranged in the axial direction and the circumferential direction. 2 and an outer cylindrical body 3 of a polygonal tube that covers the inner cylindrical body 2 and whose vertical cross section in a direction orthogonal to the axial direction forms a regular polygon.

  Here, the inner cylinder 2 and the outer cylinder 3 both have a width in a direction orthogonal to the axial direction of the structure 1, that is, a diameter when these are viewed macroscopically as a cylindrical body in the axial direction. ing.

  FIG. 3 is a plan view of the structure 1. As shown in FIG. 3, the inner cylinder 2 has a regular hexagonal cross section when cut in a direction perpendicular to the axial direction of the structure 1 at a predetermined position.

  The vertical cross section at each position distant from the predetermined position on both sides in the predetermined distance axial direction is a regular hexagon obtained by rotating the regular hexagon at the predetermined position about 30 ° (= 180 ° / 6) around the axis. It has a square shape.

  Moreover, in the inner cylinder 2, as shown in FIGS. 1-3, the mountain fold part 24 is formed in the line which connects each side part 21 of each regular hexagon mentioned above to the valley fold part 23 and the top parts 22 corresponding to a corner | angular part. .. Are formed between the valley fold portion 23 and the mountain fold portion 24 in a regular and continuous manner.

  In other words, in the inner cylindrical body 2, the structural unit surface 25 having a substantially quadrilateral shape (rhombus) is formed by connecting the apexes 22 of each regular hexagon. And the mountain fold part 24 is formed in the side part of this structural unit surface 25, Furthermore, the valley fold part 23 (side part 21) is formed in the center part (on a diagonal line) of this structural unit surface 25, and individual Two plane portions 25A, 25A having substantially isosceles triangles forming the minimum structural unit are formed on the structural unit surface 25.

  Thereby, it becomes the structure by which the plane parts 25A and 25A were connected by the side part 21 (valley fold part 23) (sharing the side part 21 (valley fold part 23)), and the cross section is V-shaped in the structural unit surface 25. Formed. And this structural unit surface 25 is regularly continuing in the axial direction and the circumferential direction on the surface of the inner cylinder 2, The inner cylinder 2 has comprised the polyhedral structure with which the unevenness | corrugation was regularly continued. . In the present specification, a portion formed in a valley shape when viewed from the surface side of the structure 1 is a valley fold portion 23, and a portion formed in a mountain shape is a mountain fold portion 24.

  4 is a cross-sectional view taken along line AA in FIG. In the inner cylinder 2, as shown in FIGS. 1-4, each top part 22 has comprised the substantially plane part, and the outer cylinder 3 is couple | bonded in this each top part 22 (in FIG. 3, FIG. 4). (See the connecting portion P indicated by a cross).

  As shown in FIGS. 1 to 3, the outer cylindrical body 3 has a regular twelve (2 × 6) square shape in cross section in the vertical direction. As a result, when the outer cylinder 3 is arranged on the outer periphery of the inner cylinder 2, each side 31 is aligned with each apex 22 of the regular hexagon shifted about 30 ° around the axis in the inner cylinder 2 as viewed in the axial direction. Then it has come to circumscribe.

  And both are combined in the state which the top part 22 which makes a plane in the inner cylinder 2, and the inner periphery of the plane part 32 which forms the regular dodecagon side part 31 in the outer cylinder 3 contact | abut. Yes. In the present embodiment, the top portion 22 of each planar portion 25A of the inner cylindrical body 2 is coupled to the outer cylindrical body 3, and the coupling portion P is continuous in the axial direction and the circumferential direction corresponding to the planar portion 25A. . The contact portion between the top portion 22 of the inner cylindrical body 2 and the flat portion 32 of the outer cylindrical body 3 is joined by welding by spot welding or the like, adhesion using an adhesive, or the like.

  Next, the shock absorbing performance of the structure 1 will be described with reference to FIG. FIG. 5 is a diagram showing the result of simulation analysis of the behavior when a load is applied to the structure 1 from one side in the axial direction by CAE (Computer Aided Engineering).

  In evaluating the shock absorbing performance of the structure 1 shown in FIG. 1, the inventor analyzed the behavior when a compressive load F as shown in FIG. 5 was added thereto. In this analysis, as shown in FIG. 5, the structure 1 is placed on the pedestal X so that the axial direction is directed upward and downward. The amount of deformation was calculated.

  Here, in FIG. 5, this analysis result is shown in a cross-sectional view corresponding to FIG. 4, FIG. 5 (a) shows a state before the compression load F is applied, and FIG. 5 (b) shows the compression load. The state immediately after adding F, FIG. 5C, shows a state when a compressive load is further applied from the state of FIG. 5B. Further, in FIG. 5, the magnitude of the deformation amount of each part is shown by color shading, and the larger the deformation amount, the darker the color.

  According to FIG.5 (b), when the compressive load F is added to the structure 1, big deformation | transformation generate | occur | produced in each connection part P (refer FIG. 4) and the peripheral part by the side where the compressive load F acts. (See the deformed portion α in the figure).

  At this time, as shown in the drawing, the structural unit surfaces 25, 25,... Of the inner cylinder 2 project inward with the valley folds 23 folded, and are flattened in the outer cylinder 3. 32 protrudes outward between the joint portions P and is crushed.

  When the compressive load F is further applied, as shown in FIG. 5C, the deformation amount and the deformation region at each deformation location α increase, and the protruding amount of the structural unit surface 25 and the flat surface portion 32 is further increased. It has become.

  Here, from the analysis result shown in FIG. 5, the inventor firstly compresses the structure 1 when the compressive load F is applied to the structure 1 by joining the inner cylinder 2 and the outer cylinder 3 at the top 22. It has been found that deformation occurs locally at the joint P on the load F side and in the vicinity thereof. And it discovered that propagation in the axial direction of a compressive deformation was suppressed by receiving the compressive load F in the coupling | bond part P and its peripheral part in this way.

  When the structure 1 is compressed and deformed, the inner cylinder 2 is regularly deformed for each coupling portion P, so that the outer cylinder 3 can also be regularly deformed for each coupling portion P. As a result, The present inventors have found that the structure 1 can be deformed substantially uniformly in the axial direction and the circumferential direction while receiving the compressive load F in cooperation with the inner cylinder 2 and the outer cylinder 3.

  In this way, a plane connecting the sides 21 and the tops 22 of the regular polygons (here regular hexagons) spaced apart in the axial direction is formed into a valley fold 23 and a mountain fold 24 to form a substantially isosceles flat plane 25A. By forming the structure 1 in which the inner cylinder 2 having the multi-face structure and the outer cylinder 3 having a vertical polygonal cross section (here, a regular dodecagon) are joined at the top portion 22, The compressive load F acting from one side can first be locally received at each coupling portion P and its periphery by the cooperation of the inner cylinder 2 and the outer cylinder 3. As a result, it is possible to improve the durability from when the compressive load F acts until the structure 1 is completely compressed and deformed.

  Further, by connecting the inner cylindrical body 2 and the outer cylindrical body 3 for each top portion 22 of each flat portion 25A, when the compressive deformation proceeds, both the inner cylindrical body 2 and the outer cylindrical body 3 are axially moved as described above. Since the structure 1 can be deformed substantially uniformly in the circumferential direction, the substantially entire structure 1 contributes to the shock absorption of the compression load F. As a result, the performance weight efficiency (impact energy absorption amount / the entire structure 1). Weight) can be improved.

  Further, as in the present embodiment, the inner cylinder 1 is a regular n-gon (n = 6), while the outer cylinder 2 is a regular 2n (= 12), and the top 22 of the inner cylinder 2 and the outer By arrange | positioning so that the plane part 32 of the cylinder 3 may correspond, the top part 22 of the inner cylinder 2 and the inner peripheral part of the plane part 32 of the outer cylinder 3 can be reliably contacted, Can be reliably combined.

  By the way, it is known that a polygonal tube having a regular polygonal cross section in the vertical direction exhibits the highest durability against an axial load when the cross section is a dodecagon (Yoshiaki Nakazawa, Three others, “Influence of cross-sectional shape factor on plastic buckling behavior of thin polygonal member”, Transactions of the Japan Society of Mechanical Engineers (A) Paper No. 06-0899, March 2007, Vol. 73, No. 727, 331 See page 337).

  Therefore, as in the present embodiment, the inner cylinder 1 is a regular hexagon (n = 6), and the vertical cross section of the outer cylinder 3 is a regular dodecagon, thereby compressing the load F in the outer cylinder 3. The durability against the maximum can be improved.

  Next, another embodiment of the present invention will be described with reference to FIGS. 6 is a perspective view showing a structure according to another embodiment of the present invention. FIG. 7A is a perspective view of an outer cylindrical body constituting the structure of FIG. 6, and FIG. FIG. 7C is a view showing a state in which the outer cylindrical body and the inner cylindrical body are coupled with the outer cylindrical body being in a transparent state.

  As shown in FIGS. 6 and 7, the structure 1 ′ has a configuration in which the positional relationship between the inner cylindrical body 2 and the outer cylindrical body 3 in the structure 1 is reversed inside and outside. That is, an outer cylindrical body 4 having a polyhedral structure in which irregularities are regularly arranged in the axial direction and the circumferential direction, and an inner cylindrical body of a polygonal tube that is covered with the outer cylindrical body 4 and whose vertical cross section forms a regular polygon. 5. And as for the outer cylinder body 4 and the inner cylinder body 5, the width | variety of the direction orthogonal to the axial direction of structure 1 'is made constant in the axial direction.

  FIG. 8 is a plan view of the structure 1 ′. In the present embodiment, as shown in FIG. 8, the outer cylinder 4 has a regular hexagonal cross section at a predetermined position, as in the inner cylinder 2 of the structure 1, and from the predetermined position. The vertical cross-sections at the respective positions apart on both sides in the predetermined axial direction form a regular hexagon obtained by rotating the regular hexagon at the predetermined position about 30 ° around the axis when viewed from the axial direction.

  And in the outer cylinder 4, the mountain fold part 44 is formed in the line | wire which connects the valley fold part 43 and the top parts 42 to each side part 41 of each regular hexagon mentioned above. For this reason, in the outer cylindrical body 4, a structural unit surface 45 having a substantially quadrilateral shape is formed by connecting the top portions 42, and further, a substantially isosceles triangle is formed between the valley fold portion 43 and the mountain fold portion 44. Are formed in a regular and continuous manner.

  9 is a cross-sectional view taken along line BB in FIG. In the present embodiment, unlike the structure 1, as shown in FIGS. 6 to 9, instead of the tip of the top portion 42 being a sharp corner, in the side portion 41, the central portion is axially arranged in the axial direction. Parallel plane portions 43a are formed. And in the outer cylinder 4, the inner cylinder 5 is couple | bonded in this plane part 43a (refer the coupling | bond part P shown by x in FIG. 8, FIG. 9).

  As shown in FIGS. 6 to 8, the inner cylindrical body 5 has a regular twelve (2 × 6) square cross section in the vertical direction. As a result, when the inner cylinder 5 is arranged on the inner periphery of the outer cylinder 4, the side portions 51 are axially arranged on the respective flat hexagonal flat portions 43 a shifted about 30 ° around the axis in the outer cylinder 4. They are inscribed in line with each other. And both are couple | bonded in the state which the flat part 43a of the outer cylinder 4 and the outer periphery of the plane part 52 which forms the regular dodecagon side part 51 in the inner cylinder 5 contact | abutted.

  In this embodiment, the plane part 43a formed in the side part 41 of each plane part 45A of the outer cylinder 4 is couple | bonded with the inner cylinder 5, and the coupling | bond part P is axial direction corresponding to the plane part 45A. And it is continuous in the circumferential direction.

  Even in the case of the structure 1 ′ having such a configuration, as in the case of the structure 1, the structure 1 ′ is completely formed after a load is applied by the cooperation of the outer cylinder 4 and the inner cylinder 5. It is possible to improve the durability until compression deformation occurs.

  Then, by joining the outer cylindrical body 4 and the inner cylindrical body 5 for each side portion 41, when the compressive deformation progresses, both the inner cylindrical body 4 and the outer cylindrical body 5 are deformed substantially equally in the axial direction and the circumferential direction. Can be made. For this reason, substantially the entire structure 1 ′ contributes to shock absorption, and as a result, the performance weight efficiency can be improved.

  Further, the inner cylindrical body has an outer peripheral portion of the flat portion 52 of the inner cylindrical body 5 because the side 51 of the inner cylindrical body 5 and the side 41 of the outer cylindrical body 4 coincide with each other in the axial direction. And the flat portion 43a of the side portion 41 of the outer cylindrical body 4 can be reliably brought into contact with each other, and both can be reliably combined.

  By the way, in each embodiment mentioned above, all the width | variety of the direction orthogonal to an axial direction of the inner cylinders 2 and 5 and the outer cylinders 3 and 4 which comprise the structure 1, 1 'is made constant in an axial direction. However, the present invention is not necessarily limited to this. For example, as in the structures 10 and 10 ′ shown in FIGS. 10 and 11, the widths of the inner cylindrical bodies 6 and 9 and the outer cylindrical bodies 7 and 8 become narrower toward one side in the axial direction (inner cylindrical body 6 and 9 and the outer cylindrical bodies 7 and 8 may be formed in a tapered shape so that the diameter when viewed as a cylindrical body macroscopically is reduced in the axial direction.

  FIG. 10 shows a structure 10 corresponding to the structure 1 (see FIGS. 1 to 5), and is constituted by an inner cylinder 6 and an outer cylinder 7 corresponding to the inner cylinder 2 and the outer cylinder 3, respectively. ing.

  In FIG. 10, the length of the side part 61 (valley fold part 63) of the inner cylindrical body 6 becomes shorter as it goes to one side in the axial direction. For this reason, it forms so that the space | interval of the top part 62 may become narrow gradually and the length of the mountain fold part 64 may become short gradually. And by such a shape, the area of the plane part 65A which comprises the structural unit surface 65 becomes small as it goes to one side of an axial direction. With such a configuration, the inner cylinder 6 has a tapered shape.

  In the outer cylindrical body 7, the length of the side portion 71 (plane portion 72) is shortened toward one side in the axial direction, and the outer cylindrical body 7 is also tapered corresponding to the inner cylindrical body 6. I am doing.

  FIG. 11 shows a structure 10 ′ corresponding to the structure 2 (see FIGS. 6 to 9), and includes an outer cylinder 8 and an inner cylinder 9 corresponding to the outer cylinder 4 and the inner cylinder 5, respectively. Has been.

  In FIG. 11, the length of the side portion 81 (valley fold portion 83) of the outer cylindrical body 8 becomes shorter as it goes to one side in the axial direction, like the inner cylindrical body 6 of the structure 10. For this reason, it forms so that the space | interval of the top part 82 may become narrow gradually and the length of the mountain fold part 84 may become short gradually. And by such a shape, the area of the plane part 85A which comprises the structural unit surface 85 becomes small as it goes to one side of an axial direction. In addition, the site | part shown with the code | symbol 83a in the figure is the plane part 83a corresponding to the plane part 43a of the outer cylinder 4. As shown in FIG.

  Corresponding to the outer cylindrical body 8, in the inner cylindrical body 9, the length of the side portion 91 (plane portion 92) is shortened toward one side in the axial direction. The cylindrical body 9 has a tapered shape.

  As described above, when the inner cylinders 6 and 9 and the outer cylinders 7 and 8 are formed in a tapered shape, the inner cylinders 6 and 9 are arranged inside the outer cylinders 7 and 8 when the structures 10 and 10 ′ are manufactured. When inserting into the inner cylinders 6 and 9, the inner cylinders 6 and 9 can be inserted from the widened side (large diameter side) of the outer cylinders 7 and 8, thereby facilitating the work in this insertion process.

  Further, when a load is applied in the axial direction to the structural bodies 10 and 10 ′ by the widened sides of the inner cylindrical bodies 6 and 9 and the outer cylindrical bodies 7 and 8, the structural body 10 is orthogonal to the axial direction. 10 'can be prevented from falling.

  By the way, the structural bodies 1, 1 ′, 10 and 10 ′ described above are coupled to the front end portion of the front side frame which extends in the vehicle front-rear direction at both sides of the front of the vehicle among the constituent members constituting the vehicle body structure. In addition, it can be applied to an impact absorbing member (crash can) that absorbs the impact of a collision load by compressing and deforming in the axial direction at the time of a frontal collision of the vehicle.

  When the structural bodies 1, 1 ′, 10, and 10 ′ are applied to the above-described shock absorbing member, for example, a base plate X shown in FIG. 5 is a connecting plate member disposed at the front end of the front side frame. Corresponding to

  When the structural bodies 10 and 10 'are applied to a structural member of a vehicle body, the side (large diameter side) whose width in the direction orthogonal to the axial direction is widened is attached to the vehicle body, and the narrow side (small diameter) It is preferable to arrange the side) toward the outside of the vehicle. By adopting such a configuration, when a load is applied obliquely in the axial direction to the narrow side, the load is first deformed at the base portion on the attachment side to the vehicle body, so that the entire structure is brought to an early stage. Can be prevented from falling down.

  In each of the embodiments described above, the vertical cross section of the cylinders 2, 4, 6, and 8 is a regular hexagon. However, the present invention is not necessarily limited to this, and at least the number n of polygonal corners. May be 4 or more.

  Further, in the cylinders 3, 5, 7, and 9 coupled to the cylinders 2, 4, 6, and 8, the shape of the cross section in the vertical direction is a regular dodecagon, but the present invention is not necessarily limited to this. It may be another regular polygon or circle instead of a thing.

In correspondence between the configuration of the present invention and the above-described embodiment,
The inner cylindrical body formed by regularly and continuously forming a substantially triangular plane portion of the present invention corresponds to the inner cylindrical bodies 2 and 6,
Similarly,
The outer cylinder covering the inner cylinder corresponds to the outer cylinders 3 and 7,
The outer cylinder formed by regularly and continuously forming a substantially triangular plane portion corresponds to the outer cylinders 4 and 8,
The inner cylinder covered by the outer cylinder corresponds to the inner cylinders 5 and 9,
The present invention is not limited only to the configuration of the above-described embodiment, and many embodiments can be obtained.

DESCRIPTION OF SYMBOLS 1, 1 ', 10, 10' ... Vehicle shock absorption structure 2, 5, 6, 9 ... Inner cylinder 3, 4, 7, 8 ... Outer cylinder 21, 41, 61, 81 ... Side part 22, 42, 62, 82 ... top 23, 43, 63, 83 ... valley fold 24, 44, 64, 84 ... mountain fold 31, 31, 71, 91 ... side

Claims (6)

A vertical cross section when cut in a direction orthogonal to the axial direction at a predetermined position forms a regular n-gon (n ≧ 4),
A vertical cross section at each position away from the predetermined position on both sides in the axial direction by a predetermined distance forms a regular n-gon obtained by rotating the regular n-gon at the predetermined position about 180 ° / n around the axis,
A line connecting each side of each regular n-gon and each top is defined as a valley fold or a mountain fold, and a substantially triangular plane is regularly and continuously between the valley fold and the mountain fold. An inner cylinder formed,
Having a cross-sectional shape circumscribing each apex of each regular n-gon of the inner cylinder,
An impact absorbing structure for a vehicle comprising an outer cylindrical body that covers an inner cylindrical body, each of which has an inner peripheral portion in contact with and coupled to each of the top portions. The outer cylindrical body is a polygonal tube whose vertical cross section forms a regular 2n square,
2. The vehicle impact absorbing structure according to claim 1, wherein a regular 2n square side portion of the outer cylindrical body and a top portion of the inner cylindrical body coincide with each other in an axial view. A vertical cross section when cut in a direction orthogonal to the axial direction at a predetermined position forms a regular n-gon (n ≧ 4),
A vertical cross section at each position away from the predetermined position on both sides in the axial direction by a predetermined distance forms a regular n-gon obtained by rotating the regular n-gon at the predetermined position about 180 ° / n around the axis,
A line connecting each side of each regular n-gon and each top is defined as a valley fold or a mountain fold, and a substantially triangular plane is regularly and continuously between the valley fold and the mountain fold. An outer cylinder formed,
Having a cross-sectional shape inscribed in each side of each regular n-gon of the outer cylinder,
An impact-absorbing structure for a vehicle comprising an inner cylindrical body covered with the outer cylindrical body, each of which has an outer peripheral part in contact with and coupled to each side part. The inner cylindrical body is a polygonal tube whose vertical cross section forms a regular 2n square,
4. The shock absorbing structure for a vehicle according to claim 3, wherein a side of the regular 2n square of the inner cylinder and a side of the outer cylinder coincide with each other when viewed in the axial direction. The regular n-gon is a regular hexagon (n = 6),
The shock absorbing structure for a vehicle according to claim 2 or 4, wherein the plane portion having a substantially isosceles triangle is regularly and continuously formed between the valley fold portion and the mountain fold portion. The said outer cylinder body and the said inner cylinder body are taper-shaped so that the width | variety of the direction orthogonal to an axial direction may become narrow, so that it goes to one side of an axial direction. Shock absorbing structure for vehicles.