JP7413298B2 - Vehicle side member structure - Google Patents

Description

The present invention relates to a vehicle body side member structure. In particular, the present invention relates to a vehicle body side member structure that can absorb impact external forces such as collision loads applied to vehicles such as automobiles.

BACKGROUND ART Impact external forces such as collision loads are sometimes applied to vehicles such as automobiles. When the collision load is applied from the front or rear of the vehicle, the side panels are located between the bumper side located at the front or rear of the vehicle and the passenger compartment side located at the center of the vehicle. The member absorbs the energy of the external impact force.

Patent Document 1 listed below shows an example of such a vehicle body side member structure. This vehicle body side member structure consists of an octagonal cross-sectional member placed on the front side of the vehicle to increase energy absorption, and a square cross-sectional member placed on the rear side of the vehicle that is easy to connect to the body. The structure is such that the different cross-sectional shapes of the members are connected by connecting members in sections where the cross-section gradually changes. However, in this configuration, the octagonal cross section has a higher buckling load, so in order to buckle from the front side of the vehicle, the gradually changing section where both members are joined is reinforced with a separate member. is taking.

Japanese Patent Application Publication No. 11-351304

However, in the above-mentioned vehicle body side member structure, since the joint portion of the gradual cross-sectional change section is reinforced using another member, there is an inconvenience that both cost and weight increase.

The present invention has been devised in view of the above points, and the problem to be solved by the present invention is to change the basic cross-sectional shape of the side member that performs the energy absorption function to substantially the same shape. The objective is to reduce the cost and weight by improving the shape and without reinforcing the structure with separate members.

In order to solve the above problems, the vehicle body side member structure according to the present invention takes the following measures.

A first aspect of the present invention is a vehicle body that is disposed in an elongated shape between a bumper side and a passenger compartment side when viewed in the longitudinal direction of the vehicle, and that an impact external force is applied from the bumper side to the side member side. The side member has a structure in which the side member is divided in the longitudinal direction into a priority energy absorption zone having a high priority for performing an energy absorption function, a subsequent energy absorption zone having a low priority for performing an energy absorption function; A connection energy absorption zone is set that connects the priority energy absorption zone and the subsequent energy absorption zone, and the priority energy absorption zone, the subsequent energy absorption zone, and the connection energy absorption zone are arranged in basic directions perpendicular to the longitudinal direction. The basic cross-sectional shapes are substantially the same, and the basic cross-sectional shapes are polygonal closed cross-sectional shapes with an inward concave shape, and The recess depth is formed deeper in the subsequent energy absorption zone than in the priority energy absorption zone, and the recess depth of the connecting energy absorption zone connects the priority energy absorption zone and the subsequent energy absorption zone. This is a vehicle body side member structure that is formed in a shape that is inclined in the longitudinal direction.

A second invention of the present invention is the vehicle body side member structure according to the first invention, wherein the connection energy absorption zone is a first connection energy absorption zone set on the bumper side of the priority energy absorption zone. , at least two second connected energy absorbing zones are set on the passenger compartment side of the priority energy absorbing zone, and the first connected energy absorbing zone is located further in the longitudinal direction than the second energy absorbing connecting zone. The body side member structure has a short length.

A third invention of the present invention is the vehicle body side member structure according to the first invention or the second invention, wherein the priority energy absorption zone, the subsequent energy absorption zone, and the connection energy absorption zone are basically The vehicle body side member structure has a symmetrical cross-sectional shape.

A fourth aspect of the present invention is the vehicle body side member structure according to any one of the first to third aspects described above, wherein the polygonal shape forming the closed cross-sectional shape is a hexagonal cross-sectional shape. It has a body side member structure.

A fifth invention of the present invention is the vehicle body side member structure according to any one of the first to fourth inventions described above, wherein two recessed shapes are formed, and the two recessed shapes are This is a vehicle body side member structure formed at a position facing the polygonal shape.

A sixth invention of the present invention is the vehicle body side member structure according to any one of the first to fifth inventions, wherein the side member is a front side member of an electric vehicle. be.

According to the above-mentioned means of the present invention, the basic cross-sectional shape of the side member that performs the energy absorption function is made to be substantially the same shape, and the cost and weight can be reduced without adopting a structure of reinforcing with a separate member. can be achieved.

FIG. 1 is a schematic perspective view of an entire vehicle showing a configuration in which a front side member of an electric vehicle is provided with a vehicle body side member structure according to the present embodiment. FIG. 2 is a schematic diagram of the front side member of the electric vehicle in FIG. 1 when viewed from the back side. FIG. 3 is a perspective view showing an extracted front side member portion in FIGS. 1 and 2. FIG. FIG. 3 is a plan view of the front side member portion shown in FIG. 2 from above. 5 is a sectional view taken along the line VV in FIGS. 3 and 4. FIG. 5 is a sectional view taken along the line VI-VI in FIGS. 3 and 4. FIG. 5 is a sectional view taken along the line VII-VII in FIGS. 3 and 4. FIG. It is a figure which shows the front side member when the length of the 1st connection energy absorption zone and the 2nd connection energy absorption zone is the same. FIG. 6 shows a front side member in which the first connection energy absorption zone has a shorter length than the second connection energy absorption zone. 9 is a diagram showing a state of buckling deformation due to energy absorption in the case of FIG. 8. FIG. 10 is a diagram showing a buckling deformation state due to energy absorption in the case of FIG. 9. FIG. 10 is a diagram showing the difference in energy absorption between the cases of FIG. 8 and FIG. 9. FIG.

Embodiments of the present invention will be described below based on the drawings. This embodiment is an embodiment applied to a front side member structure of an electric vehicle. Note that, unless otherwise specified, directions such as left and right, up and down, and front and rear in the explanation of figures indicate the directions in the figure.

<Overall configuration of electric vehicle 10>
FIG. 1 shows a schematic diagram of the overall skeletal structure of an electric vehicle 10. In FIG. 1, the front of the vehicle is indicated by an arrow Fr, and the rear thereof is indicated by Rr. The front side member 12 in the electric vehicle 10 of this embodiment is arranged at the front position of the electric vehicle 10.

FIG. 2 shows a schematic diagram of the front side member 12 of the electric vehicle 10 in FIG. 1 when viewed from the back side. Two front side members 12 are arranged in parallel in the front-rear direction at a front position of the electric vehicle 10. The two front side members 12 are arranged as members that connect a bumper 14 disposed on the left side as seen in FIG. 2 and a vehicle body frame member 18 constituting a passenger compartment 16 disposed on the right side as seen in FIG. be done. Therefore, the front side member 12 is disposed in an elongated shape between the bumper 12 side and the passenger compartment 16 side when viewed in the longitudinal direction of the vehicle. In FIG. 2, reference numeral 13 indicates a wheel (tire) disposed on the outside of the front side member 12 in the vehicle width direction.

In a frontal collision of a vehicle such as an automobile, the impact load of the collision is applied to the bumper 14, but the impact energy of the impact load is transferred to the main body frame of the vehicle body frame member 18 that constitutes the passenger compartment 16. The structure is such that the air is absorbed and the vehicle compartment 16 is protected. In FIG. 2, the direction in which a collision load is applied in a frontal collision is indicated by an arrow G, and the front side member 12 is configured such that an impact external force of the collision load is applied to the front side member 12 from the bumper 14 side. In addition, also in the following description, the collision load direction in this embodiment is shown by the arrow G.

Note that, as shown in FIGS. 1 and 2, a crash box 20 that acts as an energy absorber is usually disposed between the bumper 14 and the front side member 12. Therefore, in the event of a frontal collision of a vehicle such as an automobile, the energy of the collision load received by the bumper 14 is absorbed by the crash box 20 and the front side member 12. Generally, in the case of a light collision load, the crash box 20 performs an energy absorption function, and in the case of an excessive collision load, the front side member 12 performs an energy absorption function.

By the way, in vehicles such as automobiles equipped with an internal combustion engine (engine), large equipment constituting the internal combustion engine is arranged in a space in the front of the vehicle (a space usually referred to as an engine room). Therefore, if the bumper 14 retreats rearward in the event of an excessive collision, the large equipment may be damaged and can act as an energy absorber against the excessive collision load. However, in an electric vehicle, there is no arrangement of such large equipment in the front space of the vehicle, so in order to prevent the impact of the collision load from affecting the passenger compartment 16, it is necessary to 12, it is necessary to absorb the energy of the excessive collision load. This embodiment has a configuration for that purpose.

In addition, in the electric vehicle as well, the front side member 12 is located at the front position in the longitudinal direction (the left side position as seen in FIGS. 1 and 2) and the rear position (the right side position when seen in FIGS. 1 and 2). Left and right connecting members (not shown) are arranged to provide a strong structure. For this reason, it is preferable that the energy absorption structure of the front side member 12 be at an intermediate position in the longitudinal direction. Therefore, in this embodiment as well, the front side member 12 is configured to perform the energy absorption function preferentially at an intermediate position in the longitudinal direction.

Furthermore, it has been found from the experimental results described later that it is better to perform the buckling deformation of the front side member 12 to absorb energy in order from the front to the rear, where the collision load is applied, in terms of the energy absorption effect. are doing.

<Front side member 12>
3 and 4 show the single-item structure of the front side member 12 shown in FIGS. 1 and 2. FIG. In the following description, the front side member 12 will be simply referred to as "side member 12" unless otherwise specified. FIG. 3 shows the side member 12 three-dimensionally in a perspective view, and FIG. 4 shows a plan view of the side member 12 in FIG. 3 viewed from the direction of arrow IV.

As shown in FIGS. 3 and 4, the side member 12 is divided in the longitudinal direction into a priority energy absorption zone Zone Y and a connection energy absorption zone S connecting this priority energy absorption zone X and subsequent energy absorption zone Y are set. In FIGS. 3 and 4, the left side is the side where the bumper 14 is arranged, and the right side is the side where the vehicle body frame member 18 forming the passenger compartment 16 is located.

Note that the side member 12 of this embodiment is made of steel, and is formed by being divided into left and right halves, as shown in FIGS. 5 to 7, which will be described later, and is formed by press molding.

The connection energy absorption zone S of the present embodiment includes a first connection energy absorption zone S1 set on the bumper 14 side (the left side position as seen in FIGS. 3 and 4) of the priority energy absorption zone X, and a priority energy absorption zone Two connection energy absorption zones S2 and a second connection energy absorption zone S2 are set on the side of the vehicle compartment 16 of the X (the right side when viewed in FIGS. 3 and 4). Therefore, in the side member 12 of this embodiment, as seen in FIGS. 3 and 4, in order from the left side, the following energy absorption zone Y, the first connection energy absorption zone S1, the priority energy absorption zone X, and the second connection energy absorption zone An absorption zone S2 and a subsequent energy absorption zone Y are arranged.

In this embodiment, the set lengths are: 198 mm for the left trailing energy absorption zone Y, 20 mm for the first connected energy absorption zone S1, 252.5 mm for the priority energy absorption zone X, and 252.5 mm for the second connected energy absorption zone S2. is 40 mm, and the subsequent energy absorption zone Y on the right side is 212.9 mm.

In this embodiment, the two connected energy absorption zones S set on both sides of the priority energy absorption zone X in the longitudinal direction have different lengths. In this embodiment, the first connection energy absorption zone S1 is set shorter than the second connection energy absorption zone S2. That is, the set length is S1<S2.

5 shows a cross-sectional shape perpendicular to the longitudinal direction of the preferential energy absorption zone X, and FIGS. 6 and 7 similarly show the cross-sectional shape of the subsequent energy absorption zone Y. Although illustration of the cross-sectional shapes of the first and second connected energy absorption zones S1 and S2 is omitted, the recess depth of the recessed shape 22 described later is the intermediate depth between the priority energy absorption zone X and the subsequent energy absorption zone Y, and the length is long. The basic cross-sectional shape is the same as in FIGS. 5 to 7 except that the angle is inclined in the direction.

As shown in FIGS. 5 to 7, in this embodiment, the basic cross-sectional shapes of the priority energy absorption zone X, the subsequent energy absorption zone Y, and the connected energy absorption zone S perpendicular to the longitudinal direction are substantially It is said that they have the same morphology and shape. The basic cross-sectional shape of this embodiment is a polygonal closed cross-sectional shape, and this closed cross-sectional shape has a concave shape 22 inward. Therefore, the basic cross-sectional shape of the side member 12 in FIGS. 3 and 4 is formed as a series of continuous shapes from the left side (bumper 14 side) to the right side (vehicle compartment 16 side).

The polygonal shape, which is one of the elements forming the basic cross-sectional shape of this embodiment, is a hexagonal shape in this embodiment. The side member 12 formed in a hexagonal shape is formed of a right side member member 12A disposed on the right side and a left side member member 12B disposed on the left side when viewed in FIG. Both members 12A and 12B are overlapped at the top and bottom positions and joined by welding to be integrated into a hexagonal shape with a closed cross section. In FIGS. 5 to 7, welding locations are indicated by W with an x mark.

The right side member member 12A and the left side member member 12B are each bent to form nine surfaces on one side, and the upper and lower surfaces of both members 12A and 12B are overlapped to form a hexagonal closed cross-sectional shape. There is. In the present embodiment, an inwardly recessed shape 22 with a closed cross-sectional shape is formed at the center position in the vertical direction of the right side member member 12A and the left side member member 12B. Therefore, the concave shapes 22 are also formed on the left and right sides, and the right side member member 12A and the left side member member 12B are formed symmetrically. As a result, the hexagonal closed cross-sectional shape of the present embodiment has a left-right symmetrical shape when viewed in the left-right direction, and a vertically symmetrical shape when viewed in the up-down direction. In other words, it has a well-balanced shape. As a result, the basic cross-sectional shape is stable, and the energy absorption effect described below is performed in a well-balanced manner.

Note that the illustrated arrangement of the right side member member 12A and the left side member member 12B forming the side member 12 has the same positional relationship in FIGS. 5 and 7, but in FIG. 6, the left and right sides are reversed. It becomes. This is the difference in the direction of the cross-sectional view in FIG. That is, whereas FIGS. 5 and 7 are cross-sectional views viewed from the right, FIG. 6 is a cross-sectional view viewed from the left. For this reason, the illustrations in FIGS. 5, 7, and 6 differ in the overlapping of the upper and lower surfaces.

As shown in any of the cross-sectional forms of FIGS. 5 to 7, the basic cross-sectional form of this embodiment has an upper space K1 formed in the upper part and a lower space K2 formed in the lower part. They are formed as the same large space, and the upper space K1 and the lower space K2 are formed as communicating through a relatively narrow communication space K3 formed by a concave shape 22.

In this embodiment, as shown in FIGS. 5, 6, and 7, the recess depths of the recess shapes 22 formed in the priority energy absorption zone X and the subsequent energy absorption zone Y are different. The depth a of the concave shape 22A of the priority energy absorption zone X shown in FIG. 5 is formed to be shallower than the depth b of the concave shape 22B of the subsequent energy absorption zone Y shown in FIGS. 6 and 7. That is, the depth of the concave shape 22 is set to be a<b. In this embodiment, the depth a of the concave shape 22A of the priority energy absorption zone X is 25 mm, and the depth b of the concave shape 22B of the subsequent energy absorption zone Y is 30 mm.

The recess shape 22C of the first connection energy absorption zone S1 and the second connection energy absorption zone S2 is formed as a shape that connects the recess shape 22A of the priority energy absorption zone X and the recess shape 22B of the subsequent energy absorption zone Y. There is. Therefore, as mentioned above, the recess depth c of the recess shape 22C is between the recess depth a of the recess shape 22A in the priority energy absorption zone X and the recess depth b of the recess shape 22B in the subsequent energy absorption zone Y. It has a shape that is formed at a depth and at an angle that is inclined in the longitudinal direction. Note that since illustration of the concave shapes 22C of the first connection energy absorption zone S1 and the second connection energy absorption zone S2 is omitted, the reference numerals of the concave shapes 22C are not shown for illustration. Similarly, the illustration of the recess depth c of the recess shape 22C is also omitted, and the symbol of the recess depth c is also not shown. Therefore, the explanation of this part is only the reference numeral.

As described above, as shown in FIGS. 3 and 4, in this embodiment, the first connection energy absorption zone S1 is set to be shorter than the second connection energy absorption zone S1. Therefore, the inclination angle in the longitudinal direction of the concave shape 22C formed in the first connection energy absorption zone S1 and the second connection energy absorption zone S1 is that It has a sharper angular shape than the energy absorption zone S1. Therefore, when a collision load G is applied, stress concentration occurs in the first connection energy absorption zone S1, which has a strong angular shape, before the second connection energy absorption zone S1. As a result, the buckling deformation due to the collision load also occurs first in the first connection energy absorption zone S1, and the energy absorption action is performed first.

<Actions and effects of embodiments>
Next, the effects of the above-described embodiment will be explained.

First, in the above-described embodiment, the priority energy absorption zone X, the subsequent energy absorption zone Y, and the connection energy absorption zone S, which are arranged in a longitudinal direction of the side member 12, are perpendicular to the longitudinal direction. The basic cross-sectional shapes are substantially the same. The basic cross-sectional shape is a polygonal closed cross-sectional shape with an inward concave shape 22, and these three energy absorption zones X, Y, and S are as in the conventional case. It is a structure that is continuously arranged without using a separate member for reinforcement or the like. Thereby, cost and weight can be reduced.

Next, according to the embodiment described above, only the formation depths a, b, and c of the concave shape 22, which is one element forming the basic cross-sectional shape, are in the respective energy absorption zones X, Y, and S. The difference is that the priority energy absorption zone X is formed shallower than the subsequent energy absorption zone Y. For this reason, the shallowly formed preferential energy absorption zone X has a lower buckling strength than the subsequent energy absorption zone Y. As a result, the preferential energy absorption zone X undergoes buckling deformation prior to the subsequent energy absorption zone Y and performs the impact energy absorption function in advance.

Next, according to the present embodiment described above, the length in the longitudinal direction of the first connection energy absorption zone S1 is set shorter than that of the second energy absorption zone S2. As a result, the inclination angle of the concave shape 22 in the longitudinal direction is steeper in the first energy absorption zone S2 than in the second connection energy absorption zone S2. As a result, the stress generated when an impact load is applied is larger in the first connection energy absorption zone S1 than in the second connection energy absorption zone S2, and buckling deformation occurs first. In conjunction with the buckling deformation of this first connection energy absorption zone S1, buckling deformation occurs sequentially from the bumper side (the connection side with the first connection energy absorption zone S1) in the priority energy absorption zone X toward the rear. occurs, and the energy absorption action is performed all at once. Thereby, the energy absorption action is performed with high efficiency.

Next, in the present embodiment described above, the basic cross-sectional shape of each of the energy absorption zones X, Y, and S is symmetrical both in the left-right direction and in the left-right direction. As a result, buckling deformation during energy absorption is performed in a well-balanced manner, and energy absorption is performed efficiently and satisfactorily.

Next, in the present embodiment described above, since the polygonal shape forming the closed cross-sectional shape is a hexagonal cross-sectional shape, the cross-sectional shape is stable, and buckling deformation when a collision load is applied is also stably performed. be exposed. This also allows efficient energy absorption.

Next, the present embodiment described above is applied to the front side member 12 of an electric vehicle. Since there is no large equipment such as an internal combustion engine located in the front space where the front side member 12 of the electric vehicle is located, the energy of the collision load is reliably absorbed by the front side member 12, preventing deformation of the passenger compartment. This will protect the passenger compartment. As a result, the occupants inside the vehicle are protected.

Next, based on FIGS. 8 to 12, the difference in function and effect due to the difference in length arrangement of the first connection energy absorption zone S1 and the second connection energy absorption zone S2 in the longitudinal direction will be explained. . Note that FIGS. 8 to 12 are based on experimental results.

FIG. 8 shows an example of a case where the first connection energy absorption zone S1 and the second connection energy absorption zone S2 provided in the side member 12 have the same length in the longitudinal direction. Similarly, FIG. 9 shows an example of a case where the lengths of the first connection energy absorption zone S1 and the second connection energy absorption zone S2 provided in the side member 12 are different. In both the embodiment shown in FIG. 8 and the embodiment shown in FIG. 9, the priority energy absorption zone The arrangement order is the same as in the embodiment shown in FIG. In addition, in FIGS. 8 and 9, the positions of the first and second connected energy absorption zones S1 and S2 are only indicated by symbols, and the other zones X and Y are not shown.

The example of FIG. 8 is a case where the first and second connection energy absorption zones S1 and S2 have the same length in the longitudinal direction, and in the case of this example, the first and second connection energy absorption zones S1 , S2 have a length of 40 mm. The embodiment shown in FIG. 9 is a case where the first and second connection energy absorption zones S1 and S2 have different lengths in the longitudinal direction. 4, the first connection energy absorption zone S1 is set shorter than the second connection energy absorption zone S2. In the case of the embodiment of FIG. 9, the length of the first connection energy absorption zone S1 is 20 mm, and the length of the second connection energy absorption zone S2 is 40 mm.

FIG. 10 shows a state in which an excessive collision load is applied to the example of the side member 12 shown in FIG. 8 from the bumper 14 side (the left end side as seen in FIG. 8), causing buckling deformation and energy absorption. show. Similarly, FIG. 11 shows an example of the configuration of the side member 12 shown in FIG. 9, in which an excessive collision load is applied from the bumper 14 side (the left end side as seen in FIG. 9), causing buckling deformation and energy absorption. Indicates the condition.

In both FIGS. 10 and 11, the left end position of the side member 12 before buckling deformation is shown by the m line, and shows the state where the left end position has buckled to the n line position due to excessive collision load G. There is.

In the buckling deformation state shown in FIG. 10, buckling deformation occurs at both positions of the first connection energy absorption zone S1 and the second connection energy absorption zone S2, and also in the subsequent energy absorption zone Y on the bumper side. Buckling deformation has occurred. On the other hand, in the buckling deformation state shown in FIG. 11, the first connection energy absorption zone S1 and the following prioritized energy absorption zone X on the bumper side are buckled as a unit. . As for the energy absorption effect, the buckling deformation state shown in FIG. 11 is preferable, and the amount of energy absorption is large.

FIG. 12 shows a diagram of how the amount of energy absorbed E changes as the left end position (m-line position) moves in the embodiment of the side member 12 shown in FIGS. 8 and 9. FIG. In the diagram, the solid line diagram shows the case of FIG. 9, and the broken line diagram shows the case of FIG. 8. As shown in FIG. 12, it can be seen that the example of FIG. 9 absorbs more energy than the example of FIG. 8 even in most buckling deformation states. In this way, when the length of the first connection energy absorption zone S1 is shorter than the second connection energy absorption zone S2, the buckling deformation for energy absorption is performed efficiently and favorably, and the amount of energy absorption is also reduced. I can understand many things.

<Other embodiments>
Although specific embodiments of the present invention have been described above, the present invention can also be implemented in various other forms.

For example, although the vehicle body side member structure of the embodiment described above is a front side member structure of an electric vehicle, it is also applicable to side members of vehicles other than electric vehicles.

Moreover, although the basic cross-sectional shapes of the energy absorption zones X, Y, and S in the embodiments described above are symmetrical when viewed in the vertical and horizontal directions, they do not necessarily have to be symmetrical.

Further, in the embodiment described above, two recesses were arranged at symmetrical plane positions. However, the formation positions of the concave shapes are not symmetrical, and the number thereof may be one or three or more.

Moreover, although the formation position of the recessed shape 22 was the left and right side surface position in the above-mentioned embodiment, it may be a top and bottom surface position. That is, the cross-sectional shapes shown in FIGS. 5 to 7 may be rotated by 90 degrees.

Further, in the embodiment described above, the front side member 12 disposed between the bumper 14 disposed at the front of the vehicle and the passenger compartment 16 located in the center is equipped with an energy absorption structure. . However, this embodiment can also be applied to a rear side member disposed on the bumper side at the rear of the vehicle.

In addition, in order to preferentially and reliably buckle the portion of the priority energy absorption zone . Thereby, buckling deformation can be more reliably caused from the portion of the priority energy absorption zone X on the bumper 14 side, and the energy absorption effect can be performed more favorably.

<Operations and effects of each invention described in "Means for solving the problem">
Finally, the effects of the above-described embodiments corresponding to each invention in the above-mentioned "Means for Solving the Problems" will be added.

First, according to the first invention, the priority energy absorption zone, the subsequent energy absorption zone, and the connection energy absorption zone have substantially the same basic cross-sectional shape, and have separate reinforcement. This is a configuration in which they are connected continuously without using any members. Thereby, cost and weight can be reduced.

Further, according to the first invention, the depth of the concave shapes having substantially the same shape is formed such that the preferential energy absorption zone is shallower than the subsequent energy absorption zone. Therefore, stress is higher in the priority energy absorption zone, buckling deformation occurs first, and impact energy is absorbed preferentially.

Next, according to the second invention, the first connection energy absorption zone is formed to have a shorter length in the longitudinal direction than the second energy absorption zone. As a result, the inclination angle in the longitudinal direction of the recess depth in both zones becomes steeper in the first connection energy absorption zone. That is, the inclination angle is formed to be large. As a result, the stress in the first connecting energy absorption zone is high, leading to buckling and leading to energy absorption. Therefore, the preferential energy absorption zone also undergoes buckling deformation from the bumper side end in conjunction with the buckling deformation of the first connected energy absorption zone, and the energy absorption effect is efficiently performed.

Next, according to the third invention, the basic cross-sectional shape of the polygonal closed cross-sectional shape is formed into a symmetrical shape. This provides a well-balanced energy absorption effect.

Next, according to the fourth invention, since the polygon forming the closed cross-sectional shape is a hexagonal cross-sectional shape, the cross-sectional shape is stabilized.

Next, according to the fifth invention, the two concave shapes are arranged at symmetrical positions, so that the energy absorption action is performed in a well-balanced manner.

Next, according to the sixth invention, it can be suitably applied to the front side member of an electric vehicle where large equipment such as an internal combustion engine is not located at the front of the vehicle, and an excessive collision load is generated. This makes it possible to reliably protect the passenger compartment in the event of an accident.

10 Electric vehicle 12 Front side member (side member)
13 Wheels (tires)
14 Bumper 16 Cabin 18 Vehicle body frame member 20 Crash box 22 Recessed shape 22A Recessed shape of priority energy absorption zone 22B Recessed shape of subsequent energy absorption zone Fr Front of vehicle Rr Rear of vehicle X Priority energy absorption zone Y Subsequent energy absorption zone S Connection energy Absorption zone S1 First connection energy absorption zone S2 Second connection energy absorption zone G Collision load action direction W Welding location a Depth of concave shape of priority energy absorption zone b Depth of concave shape of subsequent energy absorption zone

Claims (6)

A vehicle body side member structure arranged in an elongated shape between a bumper side and a passenger compartment side when viewed in the longitudinal direction of the vehicle, and configured to apply an external impact force from the bumper side to the side member side,
The side member is divided in the longitudinal direction, and includes a priority energy absorption zone with a high priority that performs an energy absorption action, a subsequent energy absorption zone with a low priority that performs an energy absorption action, and the priority energy absorption zone and the subsequent energy absorption zone. A connecting energy absorbing zone is set to connect the energy absorbing zone, and the priority energy absorbing zone, the subsequent energy absorbing zone, and the connecting energy absorbing zone have a basic cross-sectional shape that is substantially orthogonal to the longitudinal direction. It is said that the shape is the same as that of
The basic cross-sectional shape is a polygonal closed cross-sectional shape with an inward concave shape,
The inward recess depth of the recess shape is formed deeper in the subsequent energy absorption zone than in the priority energy absorption zone, and the recess depth of the connected energy absorption zone is deeper than the priority energy absorption zone and the inward recess depth. Body side member structure formed as a longitudinally sloping shape connecting trailing energy absorption zones. The vehicle body side member structure according to claim 1,
The connection energy absorption zone includes at least two of a first connection energy absorption zone set on the bumper side of the priority energy absorption zone and a second connection energy absorption zone set on the passenger compartment side of the priority energy absorption zone. The vehicle body side member structure is characterized in that the first connection energy absorption zone is set to have a shorter length in the longitudinal direction than the second connection energy absorption zone. The vehicle body side member structure according to claim 1 or claim 2,
A vehicle body side member structure, wherein basic cross-sectional shapes of the priority energy absorption zone, the subsequent energy absorption zone, and the connection energy absorption zone are formed in a symmetrical shape. The vehicle body side member structure according to any one of claims 1 to 3,
In the vehicle body side member structure, the polygonal shape forming the closed cross-sectional shape is a hexagonal cross-sectional shape. The vehicle body side member structure according to any one of claims 1 to 4,
In the vehicle body side member structure, two recess shapes are formed, and the two recess shapes are formed at positions facing the polygonal shape. The vehicle body side member structure according to any one of claims 1 to 5,
The side member has a vehicle body side member structure, which is a front side member of an electric vehicle.

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