JP6339838B2 - Body front structure - Google Patents

Description

  The present invention relates to a vehicle body front structure capable of guaranteeing shock load absorption performance in both a small overlap collision, a full wrap collision, and an offset collision.

  In recent years, technological development relating to improvement of collision safety of vehicles represented by automobiles has been advanced. For example, in an offset collision, there is a high interest in collision safety against a small overlap collision (small lap collision) with a smaller amount of lap than a conventional offset collision.

  The small overlap collision is an offset collision on the outer side in the vehicle width direction than the pair of left and right front side frames. As a countermeasure, a gusset is fixed on the outer side in the vehicle width direction of the front side frame, and the impact is passed through the gusset. Many techniques that absorb a shock by transmitting a load to a front side frame and bending the front side frame are employed.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2013-203320), a gusset is provided on the outer side in the vehicle width direction of the front portion of the front side frame, and the front side frame behind the gusset is weakened by a bead on the outer side in the vehicle width direction A technique is disclosed in which a gap is formed between the tip of the gusset and the bumper beam.

  According to the technique disclosed in this document, the impact load at the time of a small overlap collision is directly connected to the front end of the front side frame or to the bumper beam connected to the front end of the front side frame via a crash box. When input, the tip of the front side frame or the crash box is crushed and the back surface of the bumper beam is retracted and pressed against the gusset. Then, an impact load is transmitted to the front side frame through the gusset, and the front side frame is bent inward in the vehicle width direction starting from the fragile portion and is made to collide with a power unit such as an engine so as to absorb the impact. I have to.

JP2013-203320A

  By the way, as disclosed in the above-mentioned document, if the front end portion of the gusset is fixed to the front side frame via the stay, the impact load at the time of the small overlap collision is received by the front end surface of the gusset, and this impact The load can be reliably transmitted in the direction of the front side frame.

  However, if the front end of the gusset is fixed to the front side frame via a stay, the front side receives the impact load in the case of an offset collision with a larger lap amount than a full lap collision (full collision) or a small lap collision. If the front end portion of the frame is deformed rearward, the deformation causes the gusset to be called inward in the vehicle width direction via the stay, which may function as a factor that impedes the impact load absorption characteristics. This also occurs when the tip surface of the gusset is connected to the bumper beam.

  In view of the above circumstances, the present invention can transmit the impact load to the front side frame through a gusset in the case of a small overlap collision, and the gusset is in an impact in the case of a full lap collision or an offset collision. It is an object of the present invention to provide a vehicle body front structure that can guarantee good shock absorption performance without functioning as a factor that inhibits absorption.

The first invention includes a front side frame extending in the front-rear direction of the vehicle body with provided on both sides in the width direction of the vehicle body, a shaft crush unit provided on a front portion of the front side frame, said shaft pinch A bumper beam connected to the front end surface of the bumper beam and extending in the vehicle width direction, and interposed between a vehicle width direction end portion side of the bumper beam and a side surface of the front side frame outside in the vehicle width direction. A vehicle body front structure having a gusset for transmitting an impact load at the time of a collision received from the front in the width direction to the front side frame, wherein the gusset is formed between the vehicle width direction end of the bumper beam and the front side frame. on the other hand, is fixed, is supported via the support portion is released by receiving the impact load at the time of full-wrap collision or offset collision with respect to the other, before Rear portion of the gusset is fixed to the front side frame, the front is supported through the supporting unit to the bumper beam.
According to a second aspect of the present invention, a front side frame is provided on both sides in the width direction of the vehicle body and extends in the front-rear direction of the vehicle body, an axial crushing portion provided in a front portion of the front side frame, and the axial crushing portion. A bumper beam connected to the front end surface of the bumper beam and extending in the vehicle width direction, and interposed between a vehicle width direction end portion side of the bumper beam and a side surface of the front side frame outside in the vehicle width direction. A vehicle body front structure having a gusset for transmitting an impact load at the time of a collision received from the front in the width direction to the front side frame, wherein the gusset is formed between the vehicle width direction end of the bumper beam and the front side frame. It is fixed to one side and supported to the other via a support part that is released by receiving an impact load at the time of a full lap collision or offset collision. The front part of the base is fixed to the bumper beam, the rear part is supported by the front side frame via the support part, and the support part is a recess formed on the outer side surface of the front side frame in the vehicle width direction. The rear portion of the gusset is supported by the recess.

  According to the present invention, the gusset is fixed to one of the end portion in the vehicle width direction of the bumper beam and the front side frame, and the support portion that is released by receiving an impact load at the time of a full wrap collision or an offset collision is applied to the other. In the case of a small overlap collision, the impact load can be transmitted to the front side frame through a gusset. On the other hand, in the case of a full lap collision or an offset collision, the bumper beam is deformed. Since the gusset is released from the support when the vehicle width direction end is bent and deformed forward, this gusset is removed from the shock load transmission path, so the gusset does not function as a factor that inhibits shock absorption and is good Shock absorption performance can be guaranteed.

Partial enlarged cross-sectional view showing a bumper structure at the front of the vehicle body according to the first embodiment Same side view as seen in the direction of arrow II in FIG. Schematic plan view showing the behavior of the front of the vehicle during a small overlap collision Same sectional plan view showing the behavior of the front part of the vehicle during a full lap collision Partial cross-sectional principal part enlarged view which shows the bumper structure of the vehicle body front part by 2nd Embodiment Same side view as seen from arrow VI in FIG. Partial cross-sectional plan view showing the behavior of the front of the vehicle during a small overlap collision Same sectional plan view showing the behavior of the front part of the vehicle during a full lap collision

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
1 to 4 show a first embodiment of the present invention. Reference numeral 1 in FIG. 1 denotes a bumper unit provided at the front part of the vehicle body. The bumper unit 1 is disposed opposite to the left and right in the vehicle width direction with the bumper beam 2 extending to the left and right in the vehicle width direction and extends to the rear of the vehicle body. It has a pair of existing front side frames 3 and a crash box 4 as a pair of left and right shaft crushing portions interposed between the back surface of the bumper beam 2 and the front side frame 3.

  An engine room 5 is formed behind the bumper beam 2 and between the front side frames 3. The engine room 5 has an engine 6, a transmission 7 connected to the output shaft of the engine 6, and the like. The power unit is mounted (see FIG. 3).

  Depending on the vehicle model, the crash box 4 may be omitted, and the front end of the front side frame 3 may be fixed to the back of the bumper beam 2 and the front may function as a crash box. Since the front part of the side frame 3 becomes an axial crushing part, the crush box 4 of this embodiment can be replaced with the front part 4 of the front side frame 3 and applied.

  The bumper beam 2 is formed of a metal material having, for example, a rectangular closed cross-section or a hat-shaped cross-section that opens at the front, and a central portion 2a that is curved with the vehicle width direction center slightly protruding forward. And an offset portion 2b provided on both sides of the central portion 2a, which is the vehicle width direction end portion side of the bumper beam 2, and the offset portion 2b is rearward at a predetermined angle along the corner portion of the front portion of the vehicle body. It is extended in a bent state. The tip of the crash box 4 is fixed to the back surface of the offset portion 2b on the central portion 2a side.

  The crash box 4 is formed in a cylindrical shape, and extends forward from the front end surface of the front side frame 3 in parallel with a line passing through the center in the vehicle width direction in the front-rear direction, and the front end surface is an offset portion 2b of the bumper beam 2 Is fixed to the back surface 2c. The crash box 4 is crushed in a bellows shape in the axial direction by an impact load input via the bumper beam 2 at the time of a collision (hereinafter referred to as “axial crushing”), and a part of the impact energy is absorbed. Is done. The crush box 4 is formed by, for example, joining the opposing surfaces of two halved members formed into a hat-shaped cross-section by pressing a thin steel plate in the middle by spot welding or the like.

  On the other hand, a gusset 9 is disposed outside the front side frame 3 in the vehicle width direction. The gusset 9 is for directly transmitting an impact load at the time of a small overlap collision to the front portion of the front side frame 3, and a main body portion (hereinafter referred to as "gusset main body") 9a formed in a rectangular cylindrical cross section. And a fixing portion 9b formed continuously at the rear end of the gusset body 9a. Two beads 9c extending in the horizontal direction are formed on the upper and lower surfaces of the fixed portion 9b on the gusset body 9a side, and the fixed portion 9b is set to be bent from the bead 9c. The fixing portion 9b is provided with a bolt or the like on a side surface (hereinafter referred to as an “outside surface”) 3a on the outer side in the vehicle width direction of the front side frame 3 located on the vehicle front side of the center of the engine 6 (see FIG. 3). It is fixed through.

  Further, the base portion of the gusset main body 9a extends forward from the front end of the fixed portion 9b so as to incline forwardly outward in the vehicle width direction, and the inner end edge portion 9e in the vehicle width direction of the front end surface 9d is the bumper beam 2 It is locked to the outer end surface 2d of the offset portion 2b via a bolt 11. Accordingly, the bolt 11 functions as a support portion that supports the gusset body 3a in a normal state.

  As shown in FIGS. 2 and 4, a U-shaped guide hole 9f whose end is opened toward the front end face 9d is formed in the inner edge 9e of the gusset body 9a. On the other hand, a nut 12 is welded to the inner surface of the outer end surface 2d of the offset portion 2b, and a bolt 11 engaged with the U-shaped guide hole 9f is screwed into the nut 12. The bolt 11 does not need to be fastened with a large torque between the outer end surface 2d of the offset portion 2b and the inner end edge portion 9e of the gusset body 9a.

  Next, the behavior when the front part of the vehicle body configured as described above undergoes a small overlap collision and a full overlap collision will be described.

<Small overlap collision>
First, the behavior of the front part of the vehicle body at the time of a small overlap collision will be described with reference to FIGS. In the figure, reference numeral Bo denotes an offset barrier, which imitates an opponent vehicle, a standing tree, a power pole, and the like.

  As shown in FIG. 1, a bumper beam 2 on the outer side (side end portion) in the vehicle width direction (side end portion) than the front side frame 3 of the vehicle, that is, an offset portion 2b is close to the offset barrier Bo from the front, and the offset portion 2b is offset barrier Bo. When a collision occurs with a load F (small overlap collision), the impact load, which is the reaction force, is transmitted to the gusset body 9a that is locked to the outer end surface 2d of the offset portion 2b by the bolt 11, and the fixing portion 9b is Via, it is applied to the outer side surface 3a of the front side frame 3 in a direction of pushing inward in the vehicle width direction from diagonally forward. As a result, the fixing portion 9b of the gusset 9 is bent starting from the bead 9c, and the rear end portion of the gusset body 9a bends and deforms the front side frame 3 inward in the vehicle width direction. When the amount of bending deformation exceeds a predetermined value, the bent portion of the front side frame 3 collides with the engine 6.

  Thereafter, when the amount of relative backward movement of the offset barrier Bo with respect to the vehicle body (the amount of relative advancement of the vehicle body with respect to the offset barrier Bo) further increases, the front side frame 3 causes the engine 6 to collide with the opposite side (the offset barrier Bo in the vehicle width direction). Press to the side not to be displaced. At this time, the uncrushed region at the front end of the front side frame 3 functions as a pressing member that further pushes the engine 6 to the opposite side by an axial impact force.

  In this way, when the heavy engine 6 is pressed to the opposite side in the vehicle width direction, the vehicle changes its direction to avoid the offset barrier Bo, thereby causing the small overlap collision of the cabin. Can be protected from. Further, the front side frame 3 can function as an energy absorber that itself absorbs energy by the bending deformation described above.

<Full lap collision>
Next, the behavior of the front part of the vehicle body at the time of a full lap collision will be described with reference to FIGS. In addition, the code | symbol Bf of the figure is a full lap barrier, and imitates an oncoming vehicle, a wall, etc.

  When the vehicle is close to the full wrap barrier Bf and the central portion 2a of the bumper beam 2 collides with the full wrap barrier Bf with a load F (full collision), an impact load as a reaction force is applied to the front surface of the central portion 2a. Is done. Since the center portion 2a is slightly protruded forward in the vehicle width direction, the center first receives an impact load and is bent backward to form a concave curve. Due to this curve deformation, both ends of the center portion 2a are brought to the vehicle width direction center. Be drawn. As a result, the front end portion of the crash box 4 in which the front end surface is fixed to the back surface 2c on the center portion 2a side of the offset portion 2b continuous to both ends of the center portion 2a is called into the vehicle width direction inside.

  Then, when the impact load received by the bumper beam 2 is transmitted to the crash box 4, as shown in FIG. 4, the front end of the bumper beam 2 is axially crushed in a state where it is slightly inclined inward in the vehicle width direction. As a result, the central portion 2a of the bumper beam 2 is further concavely deformed backward, and by this deformation, the outer end surface 2d of the offset portion 2b continuously provided at both ends thereof opens forward of the vehicle body as indicated by an arrow A in FIG. Is bent and deformed.

  Then, since the fixing portion 9b of the gusset main body 9a is fixed to the outer side surface 3a of the front side frame 3, the bolt 11 for fastening the outer end surface 2d of the offset portion 2b and the inner end edge portion 9e of the gusset main body 9a, Following the bending deformation of the offset part 2b, it moves in the direction of the front end face 9d along the U-shaped guide hole 9f formed in the inner end edge part 9e. And as shown in FIG. 4, the volt | bolt 11 remove | deviates from a U-shaped long hole, and fastening with the outer end surface 2d of the offset part 2b and the inner side edge part 9e of the gusset main body 9a is released.

  As a result, the gusset body 9a deviates from the path through which the impact load at the time of the full wrap collision is transmitted, and the gusset body 9a inhibits the shock absorption when the bumper beam 2 moves backward while axially crushing the crash box 4 due to the full wrap collision. It does not function as a factor, and good shock absorption performance can be guaranteed.

  In the present embodiment, the bolt 11 screwed into the outer end surface 2d of the offset portion 2b deviates from the U-shaped guide hole 9f formed in the inner end edge portion 9e of the gusset body 9a at the time of a full wrap collision. However, the fastening state between the offset portion 2b and the gusset body 9a is released, but a U-shaped guide hole is formed in the outer end surface 2d to open the end portion to the rear side, and from the outer end surface 2d side. The bolt 11 may be screwed into the inner end edge portion 9e of the gusset main body 9a to be fastened and fixed. In this case, at the time of full wrap collision, the U-shaped guide hole formed in the outer end surface 2 d slides and comes off from the bolt 11.

[Second Embodiment]
5 to 8 show a second embodiment of the present invention. In the first embodiment described above, the outer end surface 2d of the bumper beam 2 and the gusset body 9a are fastened by the bolt 11, and the outer end surface 2d of the bumper beam 2 moves forward in the event of a full wrap collision, so that both are fastened. In this embodiment, the gusset body 9a is released from the front side frame 3 and released at the time of a full lap collision. In addition, about the component same as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  That is, in the gusset 9 according to the present embodiment, the front end face 9d is integrally fixed to the back face 2c of the offset part 2b provided at the end of the bumper beam 2, and the gusset main body 9a is attached to the rear end face 9g. A guide pin 9h is projected.

  The gusset main body 9a extends from the back surface 2c side of the offset portion 2b in a state inclined toward the outer side surface 3a of the front side frame 3 and inward in the vehicle width direction, and faces the extending side. The outer surface 3a of the frame 3 is formed with a concave portion 3b having a triangular cross section that guides the rear portion of the gusset body 9a. The rear portion of the gusset body 9a is inserted into the recess 3b.

  The recess 3b is formed in a size having a predetermined backlash with respect to at least the top and bottom of the rear portion of the gusset 9 and the inner side in the vehicle width direction. Therefore, in a normal state, the recess 3b is formed in the rear portion of the gusset body 3a. It functions as a support part that restricts movement. Note that the position of the recess 3b substantially corresponds to the position where the fixing portion 9b of the gusset 9 shown in the first embodiment is fixed.

  Further, a guide hole 3c for inserting and guiding the guide pin 9h is formed in the rear surface of the recess 3b. As shown in FIGS. 5 and 6, in a normal state, the guide pin 9h is not inserted into the guide hole 3c, and its tip is opposed to the guide hole 3c with a slight gap. Further, the diameter of the guide hole 3c is formed to be relatively large with respect to the diameter of the guide pin 9h. Therefore, even if the shaft core of the guide pin 9h is displaced from the center of the guide hole 3c, It has a catcher structure that can be easily inserted.

  Next, the behavior when the front part of the vehicle body configured as described above undergoes a small overlap collision and a full overlap collision will be described.

<Small overlap collision>
First, the behavior of the front part of the vehicle body at the time of a small overlap collision will be described with reference to FIGS.

  As shown in FIGS. 5 and 6, the gusset body 9 a in the normal state is integrated by fixing the front end surface 9 d to the back surface 2 c of the offset portion 2 b provided at the end of the bumper beam 2. The rear end portion is supported in a state where the rear end portion is inserted into a recess 3 b formed in the outer side surface 3 a of the front side frame 3.

  At the time of the small overlap collision, the impact load is transmitted to the gusset body 9a through the back surface 2c of the offset portion 2b continuous with the end portion of the bumper beam 2 as shown by an arrow in FIG. Then, the gusset body 9a moves backward together with the offset portion 2b, and its rear portion moves rearward in the recess 3b formed in the front side frame 3, and is projected from the rear end surface 9g as shown in FIG. The guide pin 9h is inserted through a guide hole 3c formed in the rear surface of the recess 3b. Thereafter, the gusset body 9a moves backward in a state where movement in the circumferential direction is restricted by engagement with the guide pin 9h and the guide hole 3c, and the rear end face 9g comes into contact with the rear face of the recess 3b.

  Then, the outer side surface 3a of the front side frame 3 is pressed by an axial compressive load transmitted from the gusset body 9a, and the front side frame 3 is moved inward in the vehicle width direction as in FIG. 2 of the first embodiment described above. To absorb the impact load.

<Full lap collision>
On the other hand, at the time of full-wrap collision, as in the first embodiment described above, the central portion 2a of the bumper beam 2 receives a reaction force from the full-wrap barrier Bf, and the central portion 2a of the bumper beam 2 is deformed in a concave curve. It is drawn to the center in the width direction. Then, the crush box 4 in which the front end surface is fixed to the back surface 2c of the offset portion 2b continuous to both ends of the center portion 2a is crushed in the axial direction with the front end slightly pulled inward in the vehicle width direction.

  As a result, the central portion 2a of the bumper beam 2 is further concavely deformed rearward. As a result of this deformation, the outer end surface 2d of the offset portion 2b connected to both ends of the bumper beam 2 moves forward as shown by an arrow A in FIG. The gusset body 9a, which is bent and deformed so as to open, moves so that the rear portion thereof opens outward in the vehicle width direction as indicated by an arrow B in FIG.

  As a result, the rear end face 9g of the gusset main body 9a is released from the recess 3b formed in the front side frame 3, and deviates from the path through which the impact load at the time of the full wrap collision is transmitted. Therefore, when the bumper beam 2 moves backward while axially crushing the crash box 4 due to a full wrap collision, the gusset body 9a does not function as a factor that impedes shock absorption, and good shock absorption performance can be guaranteed.

  By the way, depending on the situation at the time of the full wrap collision, when the offset portion 2b is bent and deformed forward, it can be assumed that the guide pin 9h is inserted into the guide hole 3c. In this case, the offset portion 2b is bent and deformed. Accordingly, the guide pin 9h moves outward in the vehicle width direction, and is released from the recess 3b by colliding with the edge of the guide hole 3c and breaking.

  In the present embodiment, the guide pin 9h is protruded from the rear end surface 9g of the gusset main body 9a, and the guide hole 3c into which the gusset main body 9a is inserted is formed in the concave portion 3b. A guide hole may be formed, and a guide pin may be provided on the rear surface of the recess 3b.

  Note that the present invention is not limited to the above-described embodiments. For example, the behavior of the bumper unit 1 and the gusset 9 at the time of the full-wrap collision shown in each embodiment is higher than that of the above-described small overlap collision. The present invention can also be applied to an offset collision with a large lap amount.

1 ... Bumper unit,
2 ... Bumper beam,
2a ... Central part,
2b ... offset part,
2c ... the back,
2d: outer end surface,
3. Front side frame,
3a ... outer surface,
3b ... recess,
3c ... guide hole,
4 ... Crash box,
9 ... Guset,
9a ... Gusset body,
9b ... fixed part,
9d ... front end face,
9e ... inner edge,
9f ... U-shaped guide hole,
9g ... rear end face,
9h ... guide pins,
11 ... Bolt,
Bf ... Full wrap barrier,
Bo ... Offset barrier,

Claims (4)

A front side frame provided on both sides in the width direction of the vehicle body and extending in the front-rear direction of the vehicle body;
A shaft crushing portion provided at a front portion of the front side frame;
A bumper beam connected to the front end surface of the axial crushing portion and extending in the vehicle width direction;
The bumper beam is disposed between the vehicle width direction end portion side of the front side frame and the vehicle width direction outer side surface of the front side frame. In the front structure of the vehicle body having a gusset that transmits to the side frame,
The gusset is fixed to one of the end portion in the vehicle width direction of the bumper beam and the front side frame, and the other is supported through a support portion that is released by receiving an impact load at the time of a full lap collision or offset collision. Has been
The vehicle body front part structure characterized in that a rear part of the gusset is fixed to the front side frame and a front part is supported by the bumper beam via the support part. A front side frame provided on both sides in the width direction of the vehicle body and extending in the front-rear direction of the vehicle body;
A shaft crushing portion provided at a front portion of the front side frame;
A bumper beam connected to the front end surface of the axial crushing portion and extending in the vehicle width direction;
The bumper beam is disposed between the vehicle width direction end portion side of the front side frame and the vehicle width direction outer side surface of the front side frame. In the front structure of the vehicle body having a gusset that transmits to the side frame,
The gusset is fixed to one of the end portion in the vehicle width direction of the bumper beam and the front side frame, and the other is supported through a support portion that is released by receiving an impact load at the time of a full lap collision or offset collision. It has been,
The front part of the gusset is fixed to the bumper beam, and the rear part is supported by the front side frame via the support part,
The vehicle body front portion structure, wherein the support portion is a recess formed on a side surface of the front side frame on the outer side in the vehicle width direction, and the rear portion of the gusset is supported by the recess . The support portion is a bolt, and the bolt is screwed into one of the bumper beam and the front portion of the gusset and is engaged with a guide hole formed in the other. The vehicle body front structure according to claim 1 . The guide pin protrudes from one of the rear end surface of the gusset and the recess facing the rear end surface, and a guide hole into which the guide pin is inserted is formed in the other. The vehicle body front structure according to 2 .

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