Specification Title of invention: Shock absorbing member Technical field [0001] 　The present invention relates to a shock absorbing member, and more particularly to a shock absorbing member applicable to a vehicle skeleton member. Background technology [0002] 　While automobiles are required to be lighter in order to improve fuel efficiency, they are also required to have higher strength in order to ensure collision safety. A press-formed product obtained by press-molding a steel plate is used as a part of the skeleton member of the vehicle body. The front side member, which is an example of a press-formed product, is arranged so that its longitudinal direction faces from the center of the vehicle body to the front portion of the vehicle body. When a collision load from the outside of the vehicle is applied, the load is applied along the longitudinal direction of the front side member, and when the magnitude of the load exceeds the limit value, the front side member buckles and deforms to give an impact. Absorb. 　If the wall thickness is reduced in order to reduce the weight of the front side member, buckling deformation will occur with a small load, and the impact cannot be sufficiently absorbed. On the other hand, if the wall thickness is increased, sufficient shock absorption capacity can be expected, but the weight increases and fuel efficiency cannot be improved. As described above, the weight reduction and the improvement of collision resistance are contradictory characteristics, and a skeleton member of a vehicle body having both of these characteristics is desired. [0003] 　Patent Document 1 discloses a shock absorbing structure. This shock absorbing structure includes a shock absorbing member extending from one end side to the other end side, and a plurality of first deformation control units formed on the shock absorbing member and controlling the deformation of the shock absorbing member by adjusting the strength. A plurality of second deformation control units formed on the shock absorbing member and controlling the deformation of the shock absorbing member by adjusting the strength, and the plurality of first deformation control units are provided with the shock absorbing member. The second deformation control units are arranged at predetermined intervals along the longitudinal direction of the above, and the plurality of first deformation control units are arranged at predetermined intervals along the longitudinal direction. At least one is arranged between the second deformation control units, and the more the plurality of first deformation control units are arranged on the other end side in the longitudinal direction, the higher the strength is configured. Including the group that is. 　According to this shock absorbing structure, it can be deformed in a bellows shape when a shock is applied in the longitudinal direction. At the time of this deformation, the shock absorbing member is deformed in order from one end side, so that the compressive deformation of the shock absorbing member in the axial direction is stabilized and the shock absorbing performance is improved. [0004] 　Patent Document 2 discloses a method for determining the arrangement of beads. This method for determining the arrangement of beads is a method for determining the arrangement of beads on a strength member that receives a crushing load, and immediately after applying a crushing load exceeding a peak load point to the strength member without a bead. When the step of obtaining the buckling waveform generation state and the buckling waveform generation state obtained in the step are recesses in which the wall surface of the strength member is recessed inward, the concave wall surface is located at the position where the recess is generated. When the bead is arranged and the buckling waveform generation state is a convex portion in which the wall surface of the strength member is projected to the outside of the surface, it is determined to arrange the convex wall surface bead at the generation position of the convex portion. It has a process and. 　According to this bead arrangement determination method, it is said that the optimum bead and its position can be easily determined as compared with the conventional method. [0005] 　Patent Document 3 discloses a strength member for an automobile. This strength member of an automobile is a strength member of an automobile that absorbs impact energy at the time of a collision by providing a bead on a long strength member having a polygonal cross section, and the strength member is in the longitudinal direction of the pair of surfaces facing each other. A long bead extending to the surface is formed, and the long bead is formed by continuously and alternately repeating a concave portion and a convex portion with respect to a surface, and the concave portion and the convex portion are formed at the time of collision. The impact energy is absorbed by causing buckling at the boundary portion, alternately deforming the cross section with the boundary portion as a boundary, and causing buckling at a substantially central portion between the boundary portion and the adjacent boundary portion. 　According to the strength member of this automobile, the boundary portion between the concave and convex portions of the longitudinal bead and the substantially central portion of the boundary member adjacent to the boundary portion buckle to absorb impact energy. There is. Prior art literature Patent documents [0006] Patent Document 1: International Publication WO2011 / 030453A1 Patent Document 2: Japanese Patent Application Laid-Open No. 3-94137 Patent Document 3: Japanese Patent Application Laid-Open No. 11-43069 Outline of the invention Problems to be solved by the invention [0007] 　When the impact energy is absorbed by the deformation of the member, it is necessary to appropriately deform the member according to the application location of the member. 　For example, in the case of Patent Document 1, the member is bellows-deformed to absorb the impact energy, but the member may not be crushed as expected depending on how the impact energy is applied. 　Further, in Patent Document 2, the optimum arrangement of beads is defined on the premise that a predetermined impact energy is applied to the member, but even in this case, the member cannot be crushed as expected depending on how the impact energy is applied. In some cases. 　Further, in Patent Document 3, the longitudinal bead is deformed in a bellows shape by alternately deforming at the boundary between the concave portion and the convex portion, and in this respect, it has the same problem as in Patent Document 1. [0008] 　The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a shock absorbing member having an excellent shock energy absorbing capacity. Means to solve problems [0009] 　The present invention has adopted the following aspects in order to solve the above problems and achieve the object. (1) One aspect of the present invention is a hat-type hat-shaped member having a flange portion and having a hat top having a cross-sectional shape perpendicular to the longitudinal direction, which is joined to the flange portion and faces the hat top. A shock absorbing member having a plate-shaped member and a deformation guiding portion provided on at least one wall portion of the hat top portion and the plate-shaped member; the deformation guiding portion is relatively located on the wall portion. A pair of low strength portions arranged on both sides of a first high-strength portion having a high buckling resistance and a first high-strength portion having a relatively low buckling resistance and when viewed along the longitudinal direction. It has a strength portion; when viewed along the longitudinal direction, it is arranged on both sides of the deformation induction portion so as to be adjacent to each of the pair of low strength portions, and is relative to the low strength portion. It has a pair of second high-strength portions having high buckling strength. [0010] (2) In the shock absorbing member according to (1) above, the length of the first high-strength portion along the longitudinal direction is L1 (mm), and the distance between the hat top and the plate-shaped member is H. When (mm), it may be 0.8 × H ≦ L1 ≦ 2.0 × H. [0011] (3) In the shock absorbing member according to (1) or (2), the length of each of the pair of low-strength portions along the longitudinal direction is C (mm), and the top of the hat and the plate-shaped member. When the distance between them is H (mm), C ≦ 0.6 × H may be satisfied. [0012] (4) In the shock absorbing member according to any one of (1) to (3) above, the first high-strength portion is provided on the wall portion along the longitudinal direction. May have. [0013] (5) In the case of the shock absorbing member according to (4) above, the following configuration may be adopted: a pair of the first high-strength portions extending along the longitudinal direction and parallel to each other. It has the first bead portion; in the pair of low-strength portions, a region adjacent to at least one end of the pair of first bead portions is flat, and the other of at least one of the pair of first bead portions is flat. The area adjacent to the edge is flat. [0014] (6) In the case of the shock absorbing member according to (5) above, in the pair of low-strength portions, the regions adjacent to both ends of the pair of first bead portions may be flat. [0015] (7) In the case of the shock absorbing member according to any one of (4) to (6) above, the following configuration may be adopted: The pair of second high-strength portions are provided on the wall portion. It is provided along the longitudinal direction, and has a pair of second bead portions having one end adjacent to each of the pair of low-strength portions and the other end extending to the end portions of the shock absorbing member. [0016] (8) In the case of the shock absorbing member according to any one of (4) to (7) above, the following configuration may be adopted: From the wall surface of the wall portion provided with the first bead portion. The height of the first bead portion is d (mm), the width of the first bead portion is w (mm), and the plate thickness of the wall portion provided with the first bead portion is t (mm). When, at least one of d / t ≧ 2.0 and w ≧ 10 is satisfied. [0017] (9) In the shock absorbing member according to any one of (1) to (8) above, the deformation guiding portion when the first high-strength portion receives a load from the outside along the longitudinal direction. It may be a bulging portion that bulges outward in the plate thickness direction of the wall portion provided with. [0018] (10) In the shock absorbing member according to any one of (1) to (9) above, the deformation guiding portion and the pair of second high-strength portions are provided on the top of the hat and the plate-shaped member, respectively. It may be provided. [0019] (11) In the case of the shock absorbing member according to the above (10), the following configuration may be adopted: the deformation of one of the hat top and the plate-shaped member when viewed along the longitudinal direction. Deformation induction of one of the central position of the first high-strength portion provided in the guide portion and the pair of low-strength portions provided in the deformation guidance portion of the hat top and the other plate-shaped member. The distance between the top of the hat and the plate-shaped member is set to L2 (mm) from the center position of the low-strength portion provided on the portion near the first high-strength portion along the longitudinal direction. When the distance of is H (mm), L2 ≦ 6.0 × H. [0020] (12) In the case of the shock absorbing member according to (10) or (11) above, the following configuration may be adopted: in each of the deformation guiding portions, when viewed along the longitudinal direction. When the distance between the intermediate positions of the pair of low-strength portions is L3 (mm) and the distance between the top of the hat and the plate-shaped member is H (mm), 0.8 × H ≦ L3 ≦ It is 2.0 × H. [0021] (13) In the case of the shock absorbing member according to any one of (10) to (12) above, the length of each of the pair of low-strength portions along the longitudinal direction in each of the deformation guiding portions. Is C (mm), and when the distance between the top of the hat and the plate-shaped member is H (mm), C ≦ 0.6 × H may be satisfied. Effect of the invention [0022] 　According to each of the above aspects of the present invention, it is possible to provide a shock absorbing member having an excellent shock energy absorbing capacity. A brief description of the drawing [0023] FIG. 1 is a view showing a shock absorbing member according to a first embodiment of the present invention, in which (a) is a side view, (b) is a bottom view, and (c) is a line AA'in (a). The cross-sectional view of is shown. FIG. 2 is a side view showing a state in which the shock absorbing member is plastically deformed by receiving impact energy. 3A and 3B are views showing a portion B of the shock absorbing member in FIG. 2, where FIG. 3A is a vertical cross-sectional view at a center position in the width direction, and FIG. It is a bottom view. FIG. 4 is a view showing a state in which a conventional shock absorbing member is plastically deformed by receiving impact energy, (a) is a side view, and (b) is a center position in the width direction in the D portion of (a). It is a vertical sectional view in. FIG. 5 is a view showing a shock absorbing member according to a second embodiment of the present invention, and is a bottom view corresponding to FIG. 1B. FIG. 6 is a view showing a shock absorbing member according to a third embodiment of the present invention, and is a bottom view corresponding to FIG. 1B. 7A and 7B are views showing a shock absorbing member according to a fourth embodiment of the present invention, in which (a) is a plan view, (b) is a side view, (c) is a bottom view, and (d) is (b). ) Is shown in cross-sectional view along the line EE. FIG. 8 is a diagram showing a comparative example in the first embodiment, and is a bottom view corresponding to FIG. 1 (b). FIG. 9 is a diagram showing a comparative example in the first embodiment, and is a bottom view corresponding to FIG. 1 (b). FIG. 10 is a view showing an example of the invention in the first embodiment, and is a side view corresponding to FIG. 1A. 11A and 11B are side views showing a state in which the shock absorbing member is plastically deformed by receiving impact energy in the first embodiment, FIG. 11A is a comparative example shown in FIG. 8, and FIG. 10B shows FIG. This is an example of the invention shown. 12A and 12B are views showing a comparative example in the second embodiment, in which FIG. 12A is a side view, FIG. 12B is a bottom view, and FIG. 12C is a cross-sectional view taken along the line FF'of FIG. .. 13A and 13B are views showing an example of the invention in the second embodiment, in which FIG. 13A is a bottom view and FIG. 13B is a cross-sectional view taken along the line GG'in FIG. 14A and 14B are views showing a comparative example in the second embodiment, in which FIG. 14A is a bottom view and FIG. 14B is a cross-sectional view taken along the line HH'of FIG. 14A. 15A and 15B are views showing a comparative example in the second embodiment, in which FIG. 15A is a side view, FIG. 15B is a bottom view, and FIG. 15C is a cross-sectional view taken along the line II'of FIG. .. 16A and 16B are views showing an example of the invention in the second embodiment, in which FIG. 16A shows a bottom view and FIG. 16B shows a cross-sectional view taken along the line JJ'of FIG. 17A and 17B are views showing a comparative example in the second embodiment, in which FIG. 17A shows a bottom view and FIG. 17B shows a cross-sectional view taken along the line KK'of FIG. 17A. FIG. 18 is a view showing a comparative example in the second embodiment, in which (a) is a side view, (b) is a bottom view, and (c) is a cross-sectional view taken along the line LL'of (a). .. 19A and 19B are views showing a comparative example in the second embodiment, in which FIG. 19A shows a bottom view and FIG. 19B shows a cross-sectional view taken along the line MM'of FIG. 19A. 20A and 20B are views showing an example of the invention in the second embodiment, in which FIG. 20A is a bottom view and FIG. 20B is a cross-sectional view taken along the line NN'of FIG. 20A. 21A and 21B are views showing an example of the invention in the second embodiment, in which FIG. 21A is a bottom view and FIG. 21B is a cross-sectional view taken along the line OO'in FIG. 22A and 22B are views showing a comparative example in the second embodiment, in which FIG. 22A is a plan view, FIG. 22B is a side view, and FIG. 22C is a cross-sectional view taken along the line PP'of FIG. .. FIG. 23 is a diagram showing a comparative example in the second embodiment, in which (a) is a plan view and (b) is a cross-sectional view taken along the line QQ'of (a). FIG. 24 is a diagram showing an example of the invention in the second embodiment, in which (a) is a plan view and (b) is a cross-sectional view taken along the line RR'of (a). 25A and 25B are views showing an example of the invention in the second embodiment, in which FIG. 25A is a bottom view and FIG. 25B is a cross-sectional view taken along the line SS'of FIG. 25A. 26A and 26B are views showing an example of the invention in the third embodiment, in which FIG. 26A is a plan view, FIG. 26B is a bottom view, and FIG. 26C is a cross-sectional view taken along the line TT'of FIG. .. 27A and 27B are views showing an example of the invention in the third embodiment, in which FIG. 27A is a plan view, FIG. 27B is a bottom view, and FIG. 27C is a cross-sectional view taken along the line UU'of FIG. .. FIG. 28 is a view showing an example of the invention in the fourth embodiment, in which (a) is a side view, (b) is a bottom view, and (c) is a cross-sectional view taken along the line VV'of (a). .. 29A and 29B are views showing an example of the invention in the fourth embodiment, in which FIG. 29A is a plan view, FIG. 29B is a bottom view, and FIG. 29C is a cross-sectional view taken along the line WW'of FIG. .. 30A and 30B are views showing an example of the invention in the fifth embodiment, in which FIG. 30A is a plan view, FIG. 30B is a side view, and FIG. 30C is a sectional view taken along line XX'of FIG. .. Mode for carrying out the invention [0024] 　Each embodiment of the shock absorbing member according to the present invention will be described below with reference to the drawings. [First Embodiment] As 　shown in FIGS. 1A to 1C, the shock absorbing member 1 of the present embodiment has a hollow cross-sectional structure surrounded by four wall portions 1a to 1d. More specifically, the shock absorbing member 1 has a tubular shape that is long in one direction and is formed by four wall portions 1a to 1d. The one direction referred to here indicates the longitudinal direction of the shock absorbing member 1, (a) and (b) of FIG. 1 indicate the horizontal direction (X direction) of the paper surface, and (c) indicates the vertical direction of the paper surface. 　One end side of each wall portion 1a to 1d in the longitudinal direction is one end portion 1e1 that receives an impact load from the outside. In the present embodiment, the left side of the paper surface shown in FIG. 1A is the one end portion 1e1, but since the shock absorbing member 1 has a symmetrical shape in the center in the longitudinal direction, the other end portion 1e2 on the right side of the paper surface is formed. It may be configured to receive an impact load. [0025] 　The shock absorbing member 1 of the present embodiment can be used, for example, as a front side member or a rear side member which is a skeleton member of an automobile. For example, when used as a front side member, one end side in the longitudinal direction (one end 1e1) of the shock absorbing member 1 is arranged so as to face the front direction of the vehicle body, and the other end side in the longitudinal direction (the other end 1e2) is the cabin. Arranged to face the side. [0026] 　As shown in FIGS. 1A to 1C, the shock absorbing member 1 includes a molded body (hat-shaped member) 2 obtained by press-molding a metal plate, a plate-shaped member 3 joined to the molded body 2. It is composed of two members. In FIG. 1, the X direction indicates the longitudinal direction of the shock absorbing member 1, the Y direction indicates the width direction of the shock absorbing member 1, and the Z direction is a direction orthogonal to both the X direction and the Y direction. The height direction of the shock absorbing member 1 is shown. 　The molded body 2 includes a web portion 2a, a pair of vertical wall portions 2b connected to both side edges in the width direction of the web portion 2a, and a pair of flange portions 2c connected to the vertical wall portions 2b, in the longitudinal direction thereof. The vertical cross-sectional shape is hat-shaped. The web portion 2a has a rectangular shape that is long in one direction. Each of the pair of vertical wall portions 2b also has a rectangular shape that is long in one direction. As shown in FIG. 1C, the pair of vertical wall portions 2b are integrally connected to the web portion 2a at an angle slightly wider than a right angle, so that the pair of vertical wall portions 2b are connected to each other. When viewed in a cross section perpendicular to the longitudinal direction, a trapezoidal shape is formed in combination with the web portion 2a. Further, a flange portion 2c is integrally formed at the edge of each of the pair of vertical wall portions 2b. Each of these flange portions 2c has a rectangular shape that is long in one direction and is parallel to each other. [0027] 　By joining the plate-shaped member 3 to each flange portion 2c of the molded body 2, the shock absorbing member 1 having a hollow cross-sectional structure is formed. Then, the web portion 2a of the molded body 2, the pair of vertical wall portions 2b, and the plate-shaped member 3 form the four wall portions 1a to 1d constituting the shock absorbing member 1. As the joining means between each flange portion 2c of the molded body 2 and the plate-shaped member 3, spot welding, linear welding, adhesion, mechanical joining means such as screws and bolts and nuts can be adopted. [0028] 　As the material of the molded body 2 and the plate-shaped member 3, a metal plate is preferable, and a thin steel plate made of high-strength steel, an aluminum plate, an aluminum alloy plate, or the like is more preferable. In the case of a thin steel sheet, an aluminum-plated steel sheet or a galvanized steel sheet may be used. [0029] 　Of the wall portions 1a to 1d constituting the shock absorbing member 1, only the wall portion 1d composed of the plate-shaped member 3 is provided with the deformation guiding portion 4. That is, the other wall portions 1a to 1c have a flat shape in which the deformation guiding portion 4 is not provided. The flat shape referred to here means, for example, a surface shape having an average curvature of at least the outer surface of 0.0001 or less. Further, the flat-shaped region is preferably an unprocessed portion such as a bead portion that has not been processed. The above-mentioned regulation regarding a flat shape is an example, but it may be similarly applied to other embodiments and modifications. The deformation guiding portion 4 includes a high-strength portion 4a (also referred to as a first high-strength portion) having a relatively large buckling resistance and a pair of low-strength portions 4b having a relatively smaller buckling resistance than the high-strength portion 4a. Consists of. The high-strength portion 4a and the pair of low-strength portions 4b are arranged in a row along the longitudinal direction of the wall portion 1d so as to be continuous without a gap. The high-strength portion 4a is arranged so as to be sandwiched between the pair of low-strength portions 4b in the longitudinal direction of the wall portion 1d. In the wall portion 1d, the deformation guiding portion 4 is arranged so as to be sandwiched between a pair of high-strength portions 7 (also referred to as a second high-strength portion) in the longitudinal direction of the wall portion 1d. By arranging the low-strength portion 4b so as to be sandwiched between the high-strength portion 4a and the high-strength portion 7, the entire wall portion 1d becomes a region having a relatively small buckling strength. [0030] 　In the example of FIG. 1, the high-strength portion 4a occupies a region substantially central in the longitudinal direction of the wall portion 1d. Further, each low-strength portion 4b occupies the regions on both sides of the high-strength portion 4a. The high-strength portion 4a is provided with two bead portions 5, and the low-strength portion 4b is not provided with the bead portion 5 and is flat. 　The longitudinal direction of each bead portion 5 is parallel to the longitudinal direction of the wall portion 1d. Further, each bead portion 5 projects from the wall portion 1d toward the outside of the shock absorbing member 1 as shown in FIG. 1 (c). More specifically, each bead portion 5 has a triangular corner portion facing outward when viewed in a cross section perpendicular to the longitudinal direction thereof, that is, when viewed in a cross section shown in FIG. 1 (c). It has a protruding shape and can be formed by, for example, press molding. The shape of the bead portion 5 in the same cross section is not limited to a triangle, and other shapes such as a semicircular shape and a semi-elliptical shape may be adopted. [0031] 　The low-strength portion 4b is a flat-shaped region in which the bead portion 5 is not provided. The high-strength portion 4a is a cross-sectional region having a pair of convex portions formed by the bead portions 5, and is a region sandwiched between the pair of low-strength portions 4b. Focusing on the length along the surface from one side edge 3e1 of the plate-shaped member 3 to the other side edge 3e2 along the Y direction shown in FIGS. 1 (b) and 1 (c), each bead By providing the portion 5, the length of the high-strength portion 4a that functions substantially effectively along the surface (hereinafter referred to as the effective width) becomes longer than the effective width of the low-strength portion 4b. That is, the low-strength portion 4b and the high-strength portion 4a have the same linear dimensions from the side edges 3e1 to the side edges 3e2 in the Y direction when viewed from the front, but the high-strength portion 4a has a pair of bead portions 5. The effective width becomes longer because it is equipped with. More specifically, as shown in FIG. 1B, the effective width of the low-strength portion 4b is the linear length shown on the side w3. On the other hand, the effective width of the high-strength portion 4a is longer than that of the linear portion because it is accompanied by undulations at the two bead portions 5 as shown in FIG. 1 (c). 　By making the effective width of the high-strength portion 4a larger than the effective width of the low-strength portion 4b in this way, the buckling proof stress of the high-strength portion 4a is relatively higher than the buckling proof stress of the low-strength portion 4b. growing. [0032] 　The buckling strength of each of the high-strength portion 4a and the low-strength portion 4b is represented by the total yield strength F of each side on the member compression side obtained by the following equations (1) and (2). Each side on the member compression side means a portion of the high-strength portion 4a and the low-strength portion 4b in which the bead portion 5 is not provided. For example, when looking at the direction along the Y direction shown in FIG. 1B, each side on the member compression side is the side w1 between the two bead portions 5 in the case of the high strength portion 4a. It is a cross-sectional portion of a total of three sides, that is, a cross-sectional portion and a cross-sectional portion of two sides w2 from each bead portion 5 to the end portion in the width direction of the wall portion 1d. Further, in the case of the low-strength portion 4b, the side on the member compression side is a cross-sectional portion of the side w3 along the width direction of the wall portion 1d. [0033] 　F = Ce × t × σ y・ ・ ・ Equation (1) [0034] 　Ce = 1.9 × t × (E / σ y ) 0.5 × {1-0.415 × t1 / w e × (E / σ y ) 0.5 } ... Equation (2) [0035] 　In equations (1) and (2), F is the proof stress of each side, Ce is the effective width of each side represented by equation (2), and t1 is the plate thickness of each side. sigma y is the yield stress of the material of the respective sides, E is a Young's modulus of the material forming the sides, w e is the plate width of each side. Of the above parameters, the plate thickness t1 is different on each side. Specifically, when the plate thickness of the plate-shaped member 3 and the plate thickness of the flange portion 2c are the same plate thickness t, in (b) and (c) of FIG. 1, t1 = t on the side w1 and the side w2. Then, t1 = 2 × t. [0036] 　Further, in the example of FIG. 1, a bead portion 6 different from the bead portion 5 extends to both ends in the longitudinal direction of the wall portion 1d. In other words, in the example of FIG. 1, the bead portion 6 also exists in the high-strength portion 7 which is the region of the wall portion 1d excluding the deformation inducing portion 4. More specifically, a pair of bead portions 6 are provided along the longitudinal direction of the shock absorbing member 1 in each of the high-strength portions 7 on both sides of the deformation guiding portion 4. Moreover, the bead portion 6a (6) in one high-strength portion 7 is on the same straight line as the bead portion 5a (5) in the high-strength portion 4a and the bead portion 6b (6) in the other high-strength portion 7. They are lined up. Similarly, the bead portion 6c (6) in one high-strength portion 7 is also on the same straight line as the bead portion 5b (5) in the high-strength portion 4a and the bead portion 6d (6) in the other high-strength portion 7. Lined up in. Since the form shown in FIG. 1 is an example, the bead portions 5a, 6a, 6b may not be on the same straight line, and similarly, the bead portions 5b, 6c, 6d may not be on the same straight line. [0037] 　As described above, since the bead portion 6 for increasing the buckling resistance is also present in the region (high strength portion 7) excluding the deformation inducing portion 4, the low strength portion 4b in the shock absorbing member 1 is in the longitudinal direction of the wall portion 1d. In the above, it is limited to two regions where the bead portions 5 and 6 are not provided. In the present embodiment, the bead portion 6 is provided in the high strength portion 7 in order to limit the region of the low strength portion 4b, but the present invention is not limited to this embodiment, and each low strength portion 4b is formed. As described above, the region adjacent to the low-strength portion 4b may be a region having a relatively high yield stress. For example, instead of providing the bead portion 6, the yield stress of the region adjacent to the low-strength portion 4b is partially increased to increase the yield stress of the region, thereby forming the high-strength portion 7 and achieving low strength. The region of part 4b may be limited. [0038] 　Next, the dimensions of the high-strength portion 4a and the low-strength portion 4b will be described. 　The length L1 (mm) of the high-strength portion 4a along the longitudinal direction of the wall portion 1d is determined by the length of the bead portion 5 in the longitudinal direction. That is, the length L1 (mm) of the high-strength portion 4a is the distance H (mm) between the wall portion 1d provided with the deformation guiding portion 4 and another wall portion 1a arranged to face the wall portion 1d. 0.8 times or more and 2.0 times or less is preferable. Hereinafter, the distance H (mm) between the wall portion 1d and the wall portion 1a is defined as the distance between the inner surface (upper surface) of the flat portion of the wall portion 1d and the outer surface (upper surface) of the flat portion of the wall portion 1a. For example, the interval H (mm) is the same as the so-called hat height, and as shown in FIG. 1 (c), the height from the lower surface of the flange portion 2c to the flat region of the upper surface of the web portion 2a which is the top of the hat. It is a dimension. 　By defining the length L1 (mm) of the high-strength portion 4a as described above, the pair of low-strength portions 4b can be reliably separated from each other, so that the bending deformations that occur in each of the low-strength portions 4b can be mutually caused. It is possible to disperse the bending deformation points without interfering with. [0039] 　That is, if the length L1 (mm) of the high-strength portion 4a is 0.8 times or more the distance H (mm) between the wall portions 1d and 1a, the low-strength portions 4b do not come too close to each other. As a result, the deformation region at the time of bending deformation is widened, and the energy absorption capacity at the time of applying an impact load is further enhanced. That is, by setting L1 ≧ 0.8 × H, the bending deformation of one of the pair of low-strength portions 4b and the bending deformation of the other are fused to substantially result in a single node bending. Can be prevented. 　Further, if the length L1 (mm) of the high-strength portion 4a is 2.0 times or less the distance H (mm) between the wall portions 1d and 1a, bending deformation can be caused in the deformation inducing portion 4. That is, by setting L1 ≦ 2.0 × H, it is possible to cause bending deformation not only in one of the pair of low-strength portions 4b but also in both of them. [0040] 　The length C (mm) of each low-strength portion 4b along the longitudinal direction of the wall portion 1d is the high-strength portion 4a (first high-strength portion) and the high-strength portion 7 (second high-strength portion), respectively. Depends on the distance of. In the example of FIG. 1, it is determined by the distance between the bead portion 5 and the bead portion 6. The length C (mm) of each low-strength portion 4b along the longitudinal direction of the wall portion 1d is preferably 0.6 times or less of the interval H (mm). 　By setting C ≦ 0.6 × H, the place where the bending deformation occurs can be limited to a narrow region, and thereby the dispersion function of the bending deformation part by the high strength portion 4a can be further enhanced. Further, 0