JP5513903B2 - Shock absorber for vehicle - Google Patents

Description

  The present invention relates to a shock absorber for a vehicle that is disposed between a bumper beam and a side frame extending in the vehicle length direction and absorbs a collision load from the outside.

  In order to protect the engine room and the vehicle compartment from the impact at the time of collision, shock absorbers that absorb the collision load from the outside are arranged in front and rear of the vehicle. As a shock absorber, for example, a crash frame part is provided between the bumper beam and the front side frame disposed at the front part of the vehicle, and when a collision load is applied from the bumper beam side, the crash frame part is crushed to collide. What was comprised so that the energy of time might be absorbed is known (refer patent document 1).

  In order to crush the crash frame as designed and efficiently absorb the energy at the time of collision, set the collision load input position on the bumper beam side to be on the axis of the side frame, and set the collision load to Ideally, it is configured to be received by the crash frame portion and the side frame.

  However, the positions of the bumper beam and the side frame are restricted by the function and design of the vehicle, and the input position of the collision load cannot often be arranged on the axis of the side frame. For example, in order to ensure the running stability of the vehicle, there are cases where it is desired to make the vehicle with a low center of gravity by reducing the height of the side frames. Conversely, in a vehicle with a high vehicle height, the side frame may be higher than the bumper beam. Further, a link member of the suspension is connected to the side frame. If the height difference between the link member and the side frame is small, the bending moment for the side frame due to the lateral load from the wheel can be reduced. Therefore, the height of the side frame is set close to the height of the link member connection position. It is desirable.

  On the other hand, the end of the bumper beam in the vehicle width direction usually protrudes outward in the vehicle width direction from the side frame. Therefore, when the end in the vehicle width direction of the bumper beam collides with an obstacle, a lateral load is applied to the shock absorber disposed between the bumper beam and the side frame, and the bending moment generated by this lateral load causes the shock absorber to There is a risk of falling or folding.

  Therefore, Patent Document 2 proposes an impact absorbing structure that can efficiently absorb a lateral load applied to a crash box that is a shock absorber disposed between a bumper beam and a side frame. This shock absorbing structure is formed by forming a folded bead extending in the vertical direction toward the inner side in the vehicle width direction on the bumper beam side end face of the crash box. When the end of the bumper beam in the width direction of the vehicle collides with an obstacle and a load exceeding the specified value is applied to the crash box, the broken bead portion of the crash box is broken. It moves inward in the vehicle width direction and the bending moment due to lateral load is reduced.

JP 2007-112260 A JP 2009-154587 A

  However, in the shock absorbing structure disclosed in Patent Document 2, the input position of the collision load with respect to the crash box only moves in the vehicle width direction only when the broken bead is broken immediately after the collision. While the broken bead is broken and the crash box is gradually crushed to the side frame, the input position of the collision load does not gradually move in the vehicle width direction, and therefore the collision load is efficiently received by the side frame. It is not possible. Further, the height difference between the bumper beam and the side frame is not considered at all. Therefore, when the bumper beam and the side frame are different in height, the impact absorbing structure disclosed in Patent Document 2 cannot efficiently absorb the collision load by the crash box.

  The present invention has been made to solve the above-described problems, and is a vehicle capable of efficiently absorbing a collision load in a vehicle in which the input position of the collision load from the outside is not on the axis of the side frame. It is an object to provide a shock absorber.

A vehicle shock absorber according to the present invention includes a bumper beam extending in the vehicle width direction and a side frame extending in the vehicle length direction with an axis offset by a predetermined amount with respect to any one of the bumper beams in the vertical direction. In the vehicular shock absorber that absorbs a collision load from the outside by being compressed and deformed, the vehicular shock absorber is configured such that the outer peripheral portion gradually expands toward the passenger compartment. An upper surface portion provided above the axis and connecting the bumper beam and the side frame; and a lower surface portion provided below the axis and connecting the bumper beam and the side frame; The upper surface portion and the lower surface portion are set such that the inclination on the offset side with respect to the axis is larger than the inclination on the non-offset side, and the bar of the upper surface portion and the lower surface portion is The end portion for coupling to the Pabimu fragile portion is formed, the rigidity of the offset side, characterized in that it is set lower than the rigidity of the non-offset side.

In the vehicle shock absorber, a cutout portion having a different shape on the offset side and the non-offset side is formed as the fragile portion on the end portion side, and the rigidity on the offset side is determined by the shape of the cutout portion. It is characterized by being set lower than the rigidity on the non-offset side.

In the vehicle shock absorber, a concave portion is formed as the fragile portion on the end portion side, and the rigidity on the offset side is set lower than the rigidity on the non-offset side by the concave portion. .

  In the vehicle shock absorber, a wave-like portion that compresses and deforms the vehicle shock absorber in a vehicle length direction is formed on the upper surface portion and the lower surface portion.

  In the vehicular shock absorber according to the present invention, when a collision load is applied to the bumper beam, the vehicular shock absorber is gradually crushed in the offset direction of the axis of the side frame. Can be absorbed and can be reliably received by the side frame.

1 is a perspective view of a front vehicle body structure to which a vehicle shock absorber according to an embodiment is applied. It is an expansion perspective view of the shock absorber for vehicles of this embodiment. It is a top view of the shock absorber for vehicles of this embodiment. It is a side view of the shock absorber for vehicles of this embodiment. FIG. 5 is a cross-sectional view taken along line VV of the vehicle shock absorber shown in FIG. 3. FIG. 6A is a side explanatory view of the vehicle shock absorber according to the present embodiment, FIG. 6A is a state explanatory view before input of a collision load, and FIG. 6B is a state explanatory view after input of the collision load. . It is side surface explanatory drawing of the shock absorber for vehicles which is other embodiment. It is side surface explanatory drawing of the shock absorber for vehicles which is other embodiment. It is side surface explanatory drawing of the shock absorber for vehicles which is other embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view of a front vehicle body structure 10 to which a vehicle shock absorber according to this embodiment is applied. In the figure, an arrow F indicates the front of the vehicle body.

  In FIG. 1, the front body structure 10 is divided into a portion that forms a vehicle compartment R and a portion that forms an engine room E, and a toe board 12 is disposed therebetween. The toe board 12 includes a toe board center 14 and toe board sides 16a and 16b connected to both left and right sides.

  The portion that forms the passenger compartment R includes a tunnel portion 18, and floor frame sides 19 a and 19 b and side sills 20 a and 20 b are disposed on the left and right sides thereof.

  The portion that forms the engine room E includes front side frames 24a and 24b (side frames) that are connected to toe board sides 16a and 16b at the upper part of the rear end and extend forward of the vehicle body. A phosphorus hose toeboard center 26a, 26b for reinforcing the toeboard center 14 is connected to the inside of the rear ends of the front side frames 24a, 24b. The hose toe board lowers 28a and 28b are connected. Moreover, each edge part of the floor frame side 19a, 19b which comprises the part of the compartment R is connected with the lower part of the rear-end part of front side frame 24a, 24b.

  Further, above the front side frames 24a and 24b, upper frames 31a and 31b having rear ends connected to the front pillars 22a and 22b and extending forward are provided. Further, wheel aprons 30a and 30b that surround the left and right wheel housings Ha and Hb are connected to the sides of the front side frames 24a and 24b.

  Brackets 32a and 32b are connected to lower portions of floor frame sides 19a and 19b on the front side frames 24a and 24b side, and one ends of lower members 34a and 34b are connected to brackets 32a and 32b. Intermediate portions of the front side frames 24a and 24b are connected by a cross member 36 formed in a substantially U-shape for supporting an engine, a transmission, and the like housed in the engine room E. The cross member 36 is reinforced by connecting the other end portions of the lower members 34a and 34b.

  The front end portions of the front side frames 24a and 24b are connected to the rear end portions of the crash boxes 38a and 38b, which are vehicle shock absorbers, and the bumper beam 40 is connected to the front end portions of the crash boxes 38a and 38b.

  A cross member upper 42 is connected between the front end portions of the upper frames 31a and 31b. Further, brackets 44a and 44b are connected to the lower portions of the front end portions of the front side frames 24a and 24b, and a cross member lower 46 is connected between the brackets 44a and 44b. The intermediate portions of the cross member upper 42 and the cross member lower 46 are connected by a phosphorus hose member 48. The cross member upper 42 and the cross member lower 46 mainly support the radiator.

  Next, the structure of the crash box 38a, which is the vehicle shock absorber according to the present embodiment, will be described in detail with reference to FIGS. 2 is an enlarged perspective view centering on the crash box 38a, FIG. 3 is a plan view centering on the crash box 38a, FIG. 4 is a side view centering on the crash box 38a, and FIG. It is a VV sectional view. Since the crash box 38b is configured in the same manner as the crash box 38a, the description in FIGS. 2 to 5 is omitted.

  The crash box 38a includes an inner plate member 50 disposed on the inner side of the vehicle and an outer plate member 52 disposed on the outer side of the vehicle, and is joined by combining the inner plate member 50 and the outer plate member 52 from the left and right. Thus, a prismatic crush box 38a is formed. The inner plate member 50 and the outer plate member 52 are made of a plate material having a substantially U-shaped cross section that gradually expands in the direction of the vehicle compartment R and extends in the vehicle length direction. The inner plate member 50 is configured by joining a front inner plate member 54 and a rear inner plate member 56. Similarly, the outer plate member 52 is configured by joining a front outer plate member 58 and a rear outer plate member 60. The front inner plate member 54 and the front outer plate member 58 are thinner than the rear inner plate member 56 and the rear outer plate member 60 or less rigid so that the front part of the crash box 38a is crushed prior to the rear part. It is preferable to be comprised with a board | plate material.

  On the upper and lower end surfaces along the vehicle length direction of the inner plate member 50, wavy portions 62 and 64 made of irregularities along the longitudinal direction of the end surface are provided so as to be easily crushed when receiving a collision load from the front of the vehicle. It is formed. Similarly, although not shown, corrugated portions having irregularities are also formed on the upper and lower end surfaces of the outer plate member 52 along the vehicle length direction. Further, on the side surfaces of the inner plate member 50 and the outer plate member 52 along the vehicle length direction, concave portions 66 and 68 are formed along the longitudinal direction in order to give a certain strength to the crash box 38a.

  At the front end portions of the inner plate member 50 and the outer plate member 52, upper joint portions 72 and 74 joined to the upper portion of the outer plate member 70 of the bumper beam 40, and lower joint portions 76 and 78 joined to the lower portion of the outer plate member 70. Are formed (FIG. 5). An inner plate member 80 for reinforcing the bumper beam 40 is disposed inside the outer plate member 70. Further, a flange portion 82 for connecting the crash box 38a to the front end portion of the front side frame 24a is formed at the rear end portions of the inner plate member 50 and the outer plate member 52. The crash box 38a is fixed by bolts to a flange portion 84 formed at the front end portion of the front side frame 24a via the flange portion 82 (FIG. 2).

  Here, as shown in FIGS. 4 and 5, in the front vehicle body structure 10 of the present embodiment, the longitudinal axis 86 of the front side frame 24 a is offset downward from the center line 88 of the bumper beam 40. It has an offset structure. The center line 88 of the bumper beam 40 is a straight line passing through the point where the collision load indicated by the thick arrow is applied.

  As shown in FIG. 5, in the crash box 38a of the present embodiment, the upper surface portions of the inner plate member 50 and the outer plate member 52 are inclined with respect to the axis line 86 of the front side frame 24a in the direction of the vehicle compartment R. Tilt upwards at. Further, the lower surface portions of the inner plate member 50 and the outer plate member 52 are inclined downward at an inclination angle θdown toward the vehicle interior R direction with respect to the axis 86 of the front side frame 24a. The inclination angles θup and θdown are set to satisfy the relationship θup <θdown so that the inclination on the offset side of the front side frame 24a is larger than the inclination on the non-offset side. Accordingly, since the lower inclination angle θdown of the inner plate member 50 and the outer plate member 52 is larger than the upper inclination angle θup, the lower portion of the crash box 38a has a lower portion with respect to the collision load applied in the direction of the center line 88 of the bumper beam 40. Vulnerable than the top. In addition, the inclination angle θup of the upper surface portion may be 0 °.

  Further, as shown in FIG. 4, the inner plate member 50 and the outer plate member 52 are located near the upper joint portions 72 and 74 and the lower joint portions 76 and 78 near the inner plate member 50 and the outer plate member 52. Cutout portions 90, 92 and 94, 96 are formed by cutting out part of the member 52, respectively. In this case, the cutout portions 94 and 96 near the lower joint portions 76 and 78 are formed to be larger than the cutout portions 90 and 92 near the upper joint portions 72 and 74. Accordingly, the lower portion of the crash box 38a is more vulnerable than the upper portion to the collision load applied to the bumper beam 40 due to the difference in the cutout amounts of the upper and lower cutout portions 90 and 92 and the cutout portions 94 and 96.

  Further, a biting portion 98 (concave portion) that bites into the upper joint portions 72 and 74 is formed at portions near the lower joint portions 76 and 78 of the inner plate member 50 and the outer plate member 52. Therefore, the lower part of the crash box 38a is more vulnerable than the upper part to the collision load applied to the bumper beam 40.

  The structure of the crash box 38b and the positional relationship between the crash box 38b and the front side frame 24b are configured in the same manner as in the case of the crash box 38a.

  The front vehicle body structure 10 of the present embodiment is basically configured as described above. Next, the function and effect will be described.

  6A shows the state of the crash boxes 38a and 38b before the collision load is applied from the front to the bumper beam 40 constituting the front vehicle body structure 10, and FIG. 6B shows the crash box where the collision load is applied. The state which a part of 38a and 38b was crushed is shown typically.

  When a collision load is applied to the bumper beam 40 from the front of the vehicle (FIG. 6A), the bumper beam 40 is displaced rearward along the center line 88 and applies a compressive load to the crash boxes 38a and 38b.

  In this case, the crash boxes 38a and 38b are set such that the inclination angle θdown of the lower surface portions of the inner plate member 50 and the outer plate member 52 is larger than the inclination angle θup of the upper surface portion with respect to the axis 86 of the front side frames 24a and 24b. Has been. Further, the portions near the lower joint portions 76, 78 of the crash boxes 38a, 38b are notched portions 94, 96 that are notched larger than the notches 90, 92 formed at the portions near the upper joint portions 72, 74. Is formed. Furthermore, a biting portion 98 that bites into the upper joint portions 72 and 74 is formed at portions of the crash boxes 38a and 38b near the lower joint portions 76 and 78.

  Accordingly, the crash boxes 38a and 38b that have received a compressive load from the bumper beam 40 are deformed greatly from the lower side because the lower side is less rigid than the upper side and are fragile, and the bumper beam 40 is indicated by an arrow α in FIG. It will move to rotate in the downward direction shown. As a result, the offset amount Z ′ of the center line 88 of the bumper beam 40 with respect to the axis 86 of the front side frames 24a, 24b is smaller than the offset amount Z before the crash boxes 38a, 38b are deformed.

  When a collision load is continuously applied to the bumper beam 40, the bumper beam 40 moves toward the front side frames 24a, 24b while crushing the crash boxes 38a, 38b while rotating in the direction of the arrow α. The offset amount Z of the center line 88 of the bumper beam 40 is appropriately set by setting the inclination angles θup, θdown, the notches 90, 92, 94, 96 and the biting portion 98 of the upper and lower surfaces of the crash boxes 38a, 38b. Gradually decreases as the crash boxes 38a and 38b are crushed. Since the corrugated portions 62 and 64 having irregularities are formed above and below the inner plate member 50 and the outer plate member 52 constituting the crash boxes 38a and 38b, the crash boxes 38a and 38b It is easily crushed toward 24a and 24b.

  As a result, the crash boxes 38a and 38b efficiently absorb the collision load applied to the bumper beam 40, while the rotational moment of the bumper beam 40 due to the collision load with respect to the axis 86 gradually decreases as the offset amount Z decreases. Further, the crash boxes 38a and 38b are not buckled in the direction opposite to the arrow α direction. Eventually, since the collision load is applied on the substantially axial line 86 of the front side frames 24a and 24b, the front side frames 24a and 24b receive the collision load and can sufficiently protect the passenger compartment R from the impact.

  FIG. 7 shows a configuration of the crash boxes 100a and 100b that do not include the biting unit 98. Other configurations are the same as those of the crash boxes 38a and 38b. The effects equivalent to those of the crash boxes 38a and 38b can be obtained by adjusting the inclination angles of the upper and lower surfaces of the crash boxes 100a and 100b and the notch amounts of the notches 90, 92, 94, and 96.

  FIG. 8 shows a configuration of the crash boxes 102a and 102b that are not provided with the notches 90, 92, 94, and 96. FIG. Other configurations are the same as those of the crash boxes 38a and 38b. By adjusting the inclination angles of the upper and lower surfaces of the crash boxes 102a and 102b and the amount of biting of the biting portion 98, an effect equivalent to that of the crash boxes 38a and 38b can be obtained.

  FIG. 9 shows a configuration of the crash boxes 104a and 104b in the front vehicle body structure in which the axis 86 of the front side frames 24a and 24b is offset upward with respect to the center line 88 of the bumper beam 40. In this case, the crash boxes 104a and 104b have a shape in which the crash boxes 38a and 38b are turned upside down.

  When a collision load is applied to the bumper beam 40 from the front of the vehicle, the upper side of the crash boxes 104a and 104b is deformed more greatly than the lower side, so that the bumper beam 40 moves in the arrow β direction. As in the case of the crash boxes 38a and 38b shown in FIG. 6, the crash boxes 104a and 104b efficiently absorb the collision load applied to the bumper beam 40, while the collision with the axis 86 follows the decrease in the offset amount Z. The rotational moment of the bumper beam 40 due to the load is gradually reduced. Eventually, a collision load is applied on the substantially axial line 86 of the front side frames 24a and 24b, and the front side frames 24a and 24b receive the collision load and can sufficiently protect the passenger compartment R from impact.

  In addition, this invention is not limited to embodiment mentioned above, It is possible to change in the range which does not deviate from the main point of this invention.

  For example, the interval of the corrugations of the corrugated portions 64 formed on the lower side portions of the crash boxes 38a and 38b with respect to the vehicle length direction is set narrower than the corrugated portion 62 formed on the upper side portions, or By setting the amplitude of the unevenness of the wavy portion 64 to be larger than the amplitude of the unevenness of the wavy portion 62 of the upper side surface portion, the rigidity of the lower side surface portions of the crash boxes 38a and 38b with respect to the collision load applied to the bumper beam 40 can be reduced. It can be made lower than the rigidity. Further, the upper and lower members may be made of different materials so that the rigidity of the lower side surface portions of the crash boxes 38a and 38b is lower than the rigidity of the upper side surface portion. The same applies to the crash boxes 100a, 100b, 102a, 102b, 104a, and 104b.

  In the above-described embodiment, the case where the present invention is applied to the vehicle shock absorber disposed in the front portion of the vehicle 10 has been described. However, the same applies to the vehicle shock absorber disposed in the rear portion of the vehicle 10. Can be applied.

DESCRIPTION OF SYMBOLS 10 ... Front body structure 24a, 24b ... Front side frame 38a, 38b, 100a, 100b, 102a, 102b, 104a, 104b ... Crash box 40 ... Bumper beam 50 ... Inner plate member 52 ... Outer plate member 62, 64 ... Corrugated part 90, 92, 94, 96 ... notch 98 ... bite

Claims (4)

Provided between the bumper beam extending in the vehicle width direction and the side frame extending in the vehicle length direction with the axis line offset by a predetermined amount with respect to any one of the vertical directions of the bumper beam, and compressively deformed. In the vehicle shock absorber that absorbs the collision load from the outside,
The vehicle shock absorber is configured such that the outer peripheral portion gradually expands toward the passenger compartment,
An upper surface provided above the axis and connecting the bumper beam and the side frame; and a lower surface provided below the axis and connecting the bumper beam and the side frame;
The upper surface portion and the lower surface portion are set such that the inclination on the offset side with respect to the axis is larger than the inclination on the non-offset side,
A fragile portion is formed on the end portion side of the upper surface portion and the lower surface portion connected to the bumper beam,
Vehicle shock absorber, characterized in that the rigidity of the front Symbol offset side is set lower than the rigidity of the non-offset side. The vehicle shock absorber according to claim 1, wherein
On the end side, a cutout portion having a different shape on the offset side and the non-offset side is formed as the fragile portion, and due to the shape of the cutout portion, the rigidity on the offset side is higher than the rigidity on the non-offset side. A vehicular shock absorber characterized by being set low. The vehicle shock absorber according to claim 1 or 2,
A vehicular shock absorber characterized in that a concave portion is formed as the fragile portion on the end portion side, and the rigidity on the offset side is set lower than the rigidity on the non-offset side by the concave portion. In the vehicle shock absorber according to any one of claims 1 to 3,
A vehicular shock absorber that is formed with a wave-like portion that compresses and deforms the vehicular shock absorber in the vehicle length direction is formed on the upper surface portion and the lower surface portion.

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