JP2006137374A - Front body structure of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a front body structure of a vehicle capable of absorbing effectively the shock in the event of offset collision without increasing the mass. <P>SOLUTION: The front body structure of the vehicle is equipped with vertical members 5 installed on the front edge ends of front side members 4 in such a way as extending toward over the vehicle from the front edge ends of the front side members 4, radiator core side members 11 with the forefronts fixed to the vertical members 5 and the tails fixed to hood ridges 2, and outer members 7 installed on the under-part of the vertical members 5 in such a way as facing outside in the vehicle width direction. A film member 16 is installed in a space 14 surrounded by the vertical members 5, the outer members 7, and the radiator core side members 11, and is fixed to the vertical members 5, the outer members 7, and the radiator core side members 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle front structure that can reliably absorb an impact at the time of collision when an opponent vehicle has an offset collision.

  Various types of vehicle front structure against so-called offset collision are known in which the front side member of the opponent vehicle collides with the front side member of the host vehicle being displaced upward or in the vehicle width direction at the time of collision between vehicles. ing.

For example, a coupling member that couples the front end of the front side member to the front cross member and the radiator support is provided. There has been proposed a vehicle front structure that is also transmitted to the front end of a member (see, for example, Patent Document 1).
JP 2003-34264 A

  By the way, in the conventional vehicle front structure described above, when an offset collision occurs and the impact force at that time is input to the front cross member and the radiator support, the load transmission to the front side member is performed by the coupling member and the front cross member. A large load can be transmitted to the front side member if it is determined by the number of coupling points of coupling means such as bolts and nuts for coupling the radiator support.

  However, when the number of bolts and nuts is increased in this way, there is a problem that the mass of the entire vehicle front structure increases.

  In addition, with the bolt / nut connection method, it is necessary to provide bolt holes in the front cross member, radiator support, and connection member. If a large number of such bolt holes are provided, stress will occur near the bolt holes at the time of collision. Concentration may occur and break from the bolt hole. In order to prevent breakage, it is necessary to increase the distance from the end of each member to the bolt hole, or to increase the plate thickness of each member, which also increases the mass.

  Further, since the coupling member and the front cross member and the radiator support are coupled in the vehicle front-rear direction, when an impact force is input to the front cross member or the radiator support, the coupling member is connected to the coupling portion from the front cross member or the radiator support. A force to be peeled, that is, a force to shear and break the coupling member acts. In order to prevent this, it is necessary to increase the thickness of the coupling member, and there is a problem that the mass increases in this respect as well.

  The subject of this invention is providing the vehicle front part structure which can absorb the impact at the time of an offset collision effectively, without increasing a mass.

  In order to solve the above-mentioned problem, a film member is provided in a space in front of the vehicle formed by the structural members at the front of the vehicle, and the impact energy at the time of an offset collision is absorbed by the film member. .

  According to the above configuration, the film member can effectively absorb the impact at the time of the offset collision.

  The present invention also provides a vertical member extending from the front edge of the front side member toward the upper side of the vehicle at the front edge of the front side member of the vehicle, and the front end of the vertical member is connected to the vertical member. A vehicle front structure comprising a radio core side member fixed to each hood ridge and an outer member provided on the lower side of the vertical member toward the outside in the vehicle width direction, the vertical member, the outer member, A film member is provided in a space surrounded by the radio core side member, and the film member is fixed to the vertical member, the outer member, and the radio core side member.

  According to the above configuration, when an offset collision occurs and the front side member of the opponent vehicle collides with a space surrounded by the vertical member, the outer member, and the radio core side member, an in-plane force, that is, a tensile shear load is applied to the membrane member. The tensile shear load acts and is transmitted to the vertical member, outer member, radio core side member, etc., and the vertical member, outer member, radio core side member, etc. are deformed. Thereby, the impact by a collision can be absorbed effectively.

  Further, the present invention provides a vertical member extending from the front edge end portion of the front side member toward the upper side of the vehicle at the front edge end portion of the front side member of the vehicle, and a vehicle width direction at a lower portion of the vertical member. A vehicle front structure including an outer member provided toward the outside, wherein a film member is provided on a front end surface side of the front side member and a front surface side of the outer member, and the film member is connected to the front side member. It is characterized by being fixed to the outer member and the outer member, respectively.

  According to the above configuration, when the front side member of the opponent vehicle collides with the outer member of the host vehicle due to an offset collision, an in-plane force, that is, a tensile shear load acts on the membrane member. It is transmitted to the front side member and the outer member through a joint portion with the front side member and the outer member. In this case, for example, if the membrane member and the outer member are coupled by spot welding having a high coupling strength, the tensile shear load of the membrane member can be reliably transmitted to the outer member and further to the front side member. The outer member and the front side member to which the tensile shear load is transmitted are deformed, but a bending moment acts on the front end portion of the particularly rigid front side member, and the impact force is dispersed by this bending moment. Therefore, the impact energy can be absorbed efficiently.

  Further, according to the present invention, a vertical member extending from the front edge end portion of the front side member toward the upper side of the vehicle is attached to a front edge end portion of the front side member of the vehicle, and a suspension is attached to a lower portion of the vertical member. A vehicle front structure having a suspension mounting bracket for providing a membrane member on the front end surface side of the front side member, the front surface side of the vertical member, and the front surface side of the suspension mounting bracket. It is characterized by being fixed to the front side member, vertical member and suspension mounting bracket, respectively.

  According to the above configuration, when the front side member of the opponent vehicle collides with the vertical member of the own vehicle or the suspension mounting bracket due to the offset collision, an in-plane force, that is, a tensile shear load acts on the membrane member, and this tensile shear load is The front side member, the vertical member, and the suspension mounting bracket are connected to each other through the joint portion between the membrane member and the front side member, the joint portion between the membrane member and the vertical member, and the joint portion between the membrane member and the suspension mounting bracket. Communicated. Also in this case, for example, if the membrane member and the vertical member and the membrane member and the suspension mounting bracket are coupled by spot welding having a high coupling strength, the tensile shear load of the membrane member is reliably applied to the vertical member and the suspension mounting bracket. Furthermore, it can be transmitted to the front side member. And although the vertical member, suspension mounting bracket, front side member, and front side member to which the tensile shear load is transmitted are deformed, a bending moment acts on the front end portion of the particularly rigid front side member, Since the impact force can be dispersed by this bending moment, the impact energy can be absorbed efficiently.

  According to the present invention, since the membrane member is provided, it is possible to effectively absorb the impact at the time of offset collision without increasing the mass.

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

  FIG. 1 shows the front of the car with the hood removed. The vehicle front structure according to the present invention is obtained by improving the structure in the vicinity of part A in FIG.

  FIG. 2 is an exploded perspective view showing the structure on the left side of the vehicle in the vicinity of portion A in FIG. The structure on the right side of the vehicle is symmetrical with respect to the center line of the vehicle, but is basically the same as the structure on the left side of the vehicle. As shown in FIG. 2, a hood ridge 2 is disposed on the side (outside in the vehicle width direction) of the strut housing 1 along the vehicle front-rear direction. The hood ridge 2 has a substantially rectangular longitudinal section, and an inclined surface 2A is formed at the front edge of the hood ridge 2.

  The strut housing 1 has a substantially semicircular shape when viewed from above, and the strut housing 1 is formed with a strut housing reinforcement 3 projecting forward of the vehicle.

  A front side member (hereinafter referred to as a side member) 4 is disposed along the vehicle front-rear direction at the front of the vehicle, and the hood ridge 2 is positioned above the side member 4 and outside in the vehicle width direction. is doing.

  In this embodiment, the vertical member 5 is fixed to the upper surface of the front end portion of the side member 4. The vertical member 5 has a substantially rectangular cross section, and is perpendicular to the side member 4 and extends upward. Further, the upper end of the vertical member 5 is connected to a radio core upper 6 that supports the upper portion of a radiator (not shown) by bolts, nuts, and the like.

  Further, an outer member 7 is provided at the front end portion of the side member 4 toward the outer side in the vehicle width direction, and a suspension mounting bracket 8 is provided toward the lower side of the vehicle. The outer member 7 as a whole has a substantially triangular shape when viewed from above.

  The end portion of the side member 4 forms a vertical surface, and the vertical member 5, the outer member 7 and the suspension mounting bracket 8 are arranged so as to coincide with the vertical surface of the end portion of the side member 4. That is, the front side surface of the vertical member 5, the front side surface of the outer member 7, and the front side surface of the suspension mounting bracket 8 are set flush with the vertical surface of the end of the side member 4. A suspension member 9 is attached to the lower end portion of the suspension mounting bracket 8 with bolts, nuts, or the like.

  A hood ridge inner 10 is provided between the upper part of the vertical member 5 and the strut housing reinforcement 3, and a radio core side member 11 is provided between the upper part of the vertical member 5 and the hood ridge 2. . Since the vertical member 5 is provided on the inner side in the vehicle width direction than the hood ridge 2, the radial core side member 11 is disposed obliquely with respect to the vehicle center line.

  A bumper reinforcement 12 is disposed in front of the side member 4, and the bumper reinforcement 12 is attached to the front end portion of the side member 4 through a bumper stay 13 using bolts and nuts.

  FIG. 3 shows a state where the radio core upper 6 is attached to the upper part of the vertical member 5 and the suspension member 9 is attached to the lower end of the suspension mounting bracket 8. The radio core upper 6 is provided with a mounting flat plate 6A (see also FIG. 2) at the end thereof, and the radio core upper 6 is mounted on the top of the vertical member 5 via the mounting flat plate 6A.

  A headlamp 15 (see FIG. 5) is housed in a space 14 surrounded by the vertical member 5, the outer member 7, and the radio core side member 11.

  In the present embodiment, when the headlamp 15 is housed in the space 14, the film member 16 is first disposed in the space 14 as shown in FIG. 4. The membrane member 16 includes carbon fiber or aramid fiber, and a recess 16A projecting downward is formed in a portion in which the headlamp 15 is accommodated.

  FIG. 5 shows a state in which the membrane member 16 is attached in the space 14. As shown in the figure, the membrane member 16 has a peripheral portion fixed to the vertical member 5, the outer member 7, the radio core side member 11, and the inclined surface 2 </ b> A of the hood ridge 2. In FIG. 5, the hatched part is a fixed part. The membrane member 16 is fixed by spot welding.

  Next, the effect | action in the vehicle front part structure of a present Example is demonstrated using FIGS. 6A is a cross-sectional view taken along the line SA-SA in FIG. 3, FIG. 7A is a cross-sectional view taken along the line SB-SB in FIG. 3, and FIG. Each section along the line is shown.

  When the side member 17 of the opponent vehicle hits the headlamp 15 at the time of the offset collision, the headlamp 15 is crushed and the side member 17 of the opponent vehicle presses the membrane member 16 as shown in FIG. . At this time, the membrane member 16 is fixed to the vertical member 5, the outer member 7, the radio core side member 11, and the inclined surface 2 </ b> A of the hood ridge 2 on one side (vehicle width direction inner side). An in-plane force, that is, a tensile shear load (arrow A) is applied, thereby receiving an impact by the side member 17 of the counterpart vehicle.

  The tensile shear load generated on the membrane member 16 is transmitted to the side member 4 and the hood ridge 2 through the highly rigid vertical member 5, outer member 7, and radio core side member 11. As a result, as shown in FIG. 7 (b), the moment M1 acts on the front end portion of the side member 4 to deform the side member 4 outward in the vehicle width direction, and as shown in FIG. 8 (b). The moment M2 also acts to deform the side member 4 upward. Further, as shown in FIG. 8B, the moment M3 acts on the front end portion of the hood ridge 2 to deform the hood ridge 2 downward. Thereby, the impact energy can be efficiently absorbed by the entire member at the front of the vehicle body.

  In the conventional structure, the portion connecting the hood ridge 2 and the outer member 7 receives a collision load by bending the member 18 having a predetermined cross-sectional area as shown in FIG. 10, and the height of the member 18 is high. It was necessary to reduce the plate thickness and ensure the bending strength (see FIG. 12).

For example, the member 18 has a hollow rectangular column, and its cross section is as shown in FIG. Therefore, the plate thickness t of the member 18 is
t = (b−b ₀ ) / 2 = (h−h ₀ ) / 2 (1)
The bending stress σ acting on the member 18 is obtained by the following equation (2).

  Here, when the input load F is 2000 kgf, the member length L is 400 mm, the member width b is 50 mm, and the material strength (bending stress) σ is 500 MPa, the thickness t is 1.25 mm ( h = 30 mm).

  On the other hand, in this embodiment, as shown in FIG. 9, since the strength of the film member 16 is determined by the in-plane strength, the increase in the thickness of the film member 16 can be minimized.

  For example, the bending stress σ acting on the film member 16 is obtained by the following equation (3).

  Here, similarly to the above, when the input load F is 2000 kgf, the member length L is 400 mm, the member width b is 50 mm, and the material strength (bending stress) σ is 500 MPa, the thickness t is calculated from the above equation (3). 0.8 mm.

  Therefore, if the membrane member 16 in the present embodiment is employed, an increase in weight can be suppressed even when the space before the tire cannot be secured (see FIG. 12).

  According to the present embodiment, since the membrane member 16 is provided, it is possible to disperse the collision load of the side member of the opponent vehicle at the time of the collision and effectively absorb the impact energy. Further, since the membrane member 16 is disposed behind the headlamp 15, it is possible to prevent mud from the tire from entering the electrical system at the rear of the headlamp 15 during traveling.

  Further, when the membrane member 16 includes carbon fibers having high tensile strength, the plate thickness of the membrane member 16 can be reduced, and further weight reduction can be achieved. Furthermore, when the membrane member 16 includes an aramid fiber having a high breaking strength used for a bulletproof vest or the like, the shear breaking of the membrane member 16 due to the edge portion of the side member 17 of the counterpart vehicle is more effectively avoided. Can do.

  Next, a second embodiment of the present invention will be described. FIG. 13 shows a vehicle front structure according to the second embodiment. In the present embodiment, the membrane member 20 is provided on the front end surface side of the side member 4, the front surface side of the vertical member 5, the front surface side of the outer member 7, and the front surface side of the suspension mounting bracket 8.

  The periphery of the membrane member 20 is fixed to the front flange 5A of the vertical member 5, the front flange 7A of the outer member 7, and the front flange 8A of the suspension mounting bracket 8 by spot welding. In the figure, “*” marks around the membrane member 20 indicate spot welding locations.

  Further, a bolt hole 20A is formed in a substantially central portion of the membrane member 20, and a bolt (not shown) is inserted into the bolt hole 20A when the bumper stay 13 is fixed to the front flange 4A of the side member 4. .

  The inside of the outer member 7 is hollow, and weak portions 7B made up of a plurality of parallel slits are formed on the upper surface plate and the lower surface plate of the hollow portion. Other configurations are the same as those in the first embodiment.

  Note that carbon fiber or aramid fiber is formed between the front end surface side of the side member 4, the front surface side of the vertical member 5, the front surface side of the outer member 7, and the front surface side of the suspension mounting bracket 8 and the membrane member 20. A fiber member 21 may be provided. A small through hole 21 </ b> A is formed around the fiber member 21 so as to correspond to the spot welding location.

  Next, the effect | action in the vehicle front part structure of a present Example is demonstrated using FIGS. 14-16. 14A is a cross section taken along line SD-SD in FIG. 13, FIG. 15A is a cross section taken along line SE-SE in FIG. 13, and FIG. 16A is SF-SF in FIG. Each section along the line is shown.

  As shown in FIG. 14B, when the side member 17 of the opponent vehicle is displaced in the vehicle width direction and collides with the outer member 7 of the own vehicle, the outer member 7 is formed with a fragile portion 7B. The member 7 is easily crushed. Thereby, impact energy can be absorbed efficiently. In the figure, the two-dot chain line indicates the positions of the membrane member 20 and the outer member 7 when they start to be crushed.

  When the side member 17 of the opponent vehicle collides with the outer member 7 of the own vehicle, as shown in FIG. 15B, an in-plane force, that is, a tensile shear load (arrow B) acts on the membrane member 20, The tensile shear load is transmitted to the side member 4 and the outer member 7 through the joint portion between the membrane member 20 and the side member 4 and the outer member 7. In this case, the membrane member 20 and the outer member 7 are joined by spot welding having high bonding strength, and the tensile shear load of the membrane member 20 can be reliably transmitted to the outer member 7 and further to the side member 4. . Although the outer member 7 and the side member 4 to which the tensile shear load is transmitted are deformed, a bending moment (a twist is simultaneously applied to the vertical member 5) M4 acts on the front end portion of the particularly rigid side member 4. Since it is possible to disperse the impact force with this bending moment (and twist) M4, the impact energy can be absorbed efficiently.

  Next, FIG. 17 and FIG. 18 have shown the cross section along the SG-SG line of FIG. As shown in FIG. 17, when the side member 17 of the opponent vehicle collides with the vertical member 5 of the own vehicle, the vertical member 5 and the radial core side member 11 are deformed as indicated by a two-dot chain line in the figure, and the membrane member 20 A tensile shear load (arrow B) acts on the side member 4 and the side member 4 through the joint between the membrane member 20 and the side member 4 and the joint between the membrane member 20 and the vertical member 5. It is transmitted to the vertical member 5. In this case, the membrane member 20 and the vertical member 5 are coupled by spot welding having a high coupling strength, and the tensile shear load of the membrane member 20 can be reliably transmitted to the vertical member 5 and further to the side member 4. . As a result, a bending moment M5 acts on the front end portion of the highly rigid side member 4, and it becomes possible to disperse the impact force with this bending moment M5, so that the impact energy can be absorbed efficiently. it can. Further, a force (arrow C) in the forward direction of the vehicle acts on the suspension member 9 due to the bending moment M5.

  Further, as shown in FIG. 18, when the side member 17 of the opponent vehicle collides with the suspension mounting bracket 8 of the own vehicle, the suspension mounting bracket 8 and the suspension member 9 are deformed as shown by a two-dot chain line in the figure, and the membrane A tensile shear load (arrow B) acts on the member 20, and this tensile shear load is applied to the side via the junction between the membrane member 20 and the side member 4 and the junction between the membrane member 20 and the suspension mounting bracket 8. It is transmitted to the member 4 and the suspension mounting bracket 8. In this case, the membrane member 20 and the suspension mounting bracket 8 are coupled by spot welding having high coupling strength, and the tensile shear load of the membrane member 20 is reliably transmitted to the suspension mounting bracket 8 and further to the side member 4. Can do. As a result, the bending moment M6 at the front end acts on the side member 4 having high rigidity.

  On the other hand, the tensile shear load generated on the membrane member 20 acts on the vertical member 5 (arrow D), and further acts on the strut housing reinforcement 3 via the radial core side member 11, which is shown in the figure. As shown by the two-dot chain line, the vehicle tilts forward. As a result, a bending moment M7 opposite to the bending moment M6 acts on the side member 4 in the vicinity of the joint with the strut housing reinforcement 3. As a result, in the side member 4, the bending moment M6 is canceled by the bending moment M7, the deformation of the side member 4 is suppressed, and the impact energy can be absorbed efficiently.

  When the suspension mounting bracket 8 is deformed as indicated by a two-dot chain line, a bending moment M8 acts on the suspension member 9.

  19 and 20 show a third embodiment. FIG. 19 is a cross-sectional view corresponding to FIG. 14A, and FIG. 20 is an enlarged view of a portion E in FIG.

  In the present embodiment, the fiber member 21 is provided on the back surface of the membrane member 20. As shown in FIG. 13, the fiber member 21 is made of carbon fiber or aramid fiber. A through hole 21A is formed around the fiber member 21, and when spot welding the membrane member 20 to the front flange 7A of the outer member 7, the electrode 22 of the spot welder is inserted into the through hole 21A.

  Note that spot welding to the front flange 5A of the vertical member 5 and the front flange 8A of the suspension mounting bracket 8 is the same as the case of the front flange 7A of the outer member 7.

It is a perspective view which shows the front part of the motor vehicle with the bonnet opened. FIG. 2 is an exploded perspective view showing the structure on the left side of the vehicle in the vicinity of the portion A in FIG. It is a perspective view of a vehicle front part structure when a radio core upper and a suspension member are respectively attached. It is a figure which shows a mode that a film | membrane member is attached to the vehicle front part structure of FIG. It is a figure which shows a mode that the film | membrane member was fixed to the vehicle front part structure. FIG. 4 is a cross-sectional view taken along line SA-SA in FIG. 3, (a) shows a state before a collision, and (b) shows a state at the time of a collision. FIG. 4 is a cross-sectional view taken along line SB-SB in FIG. 3, (a) shows a state before a collision, and (b) shows a state at the time of a collision. It is a cross section along the SC-SC line of FIG. 3, (a) is a state before the collision, (b) is a diagram showing a state at the time of the collision. It is a figure explaining the behavior by the membrane member at the time of a collision. It is a figure explaining the behavior by the conventional structure at the time of a collision. It is a cross-sectional view of the member shown in FIG. It is a figure which shows the relationship between cross-sectional height and plate | board thickness. FIG. 8 is an exploded perspective view showing the structure on the left side of the vehicle in the vicinity of the portion A in FIG. 1 according to the second embodiment. 14A and 14B are cross sections taken along the SD-SD line in FIG. 13, where FIG. 14A shows a state before a collision, and FIG. 14A and 14B are cross sections taken along line SE-SE in FIG. 13, where FIG. 14A shows a state before a collision, and FIG. It is sectional drawing along the SF-SF line | wire of FIG. FIG. 14 is a cross-sectional view taken along line SG-SG in FIG. 13, showing a state in which a side member of the opponent vehicle has collided with a vertical member. FIG. 14 is a cross-sectional view taken along line SG-SG in FIG. 13 and shows a state in which a side member of the opponent vehicle collides with a suspension mounting bracket. FIG. 14 is a cross-sectional view taken along line SE-SE in FIG. 13, showing Example 3. It is an enlarged view of the E section of FIG.

Explanation of symbols

2 Hood Ridge 4 Front Side Member 5 Vertical Member 6 Radio Core Upper 7 Outer Member 11 Radio Core Side Member 12 Bumper Reinforce 15 Headlamp 16 Membrane Member 20 Membrane Member 21 Fiber Member

Claims (10)

  A vehicle front structure characterized in that a film member is provided in a space in front of the vehicle formed by a structural member at the front of the vehicle, and the impact energy at the time of an offset collision is absorbed by the film member. A vertical member that extends from the front edge of the front side member toward the top of the vehicle at the front edge of the front side member of the vehicle, and a front end fixed to the vertical member and a rear end fixed to the hood ridge, respectively. A vehicle front portion structure including a radial core side member and an outer member provided at a lower portion of the vertical member toward an outer side in a vehicle width direction,
A vehicle front is characterized in that a membrane member is provided in a space surrounded by the vertical member, outer member, and radio core side member, and the membrane member is fixed to the vertical member, outer member, and radio core side member, respectively. Part structure.   The vehicle front structure according to claim 2, wherein a headlamp is mounted in the space through the membrane member. A vertical member that extends from the front edge of the front side member toward the upper side of the vehicle at the front edge of the front side member of the vehicle, and a lower part of the vertical member that extends outward in the vehicle width direction. A vehicle front structure provided with an outer member,
2. A vehicle front structure comprising a membrane member provided on a front end surface side of the front side member and a front side of an outer member, and the membrane members fixed to the front side member and the outer member, respectively. A vertical member extending from the front edge of the front side member toward the upper side of the vehicle at a front edge of the front side member of the vehicle; and a suspension mounting bracket for attaching a suspension to a lower portion of the vertical member; A vehicle front structure comprising:
A membrane member is provided on the front end surface side of the front side member, the front surface side of the vertical member, and the front surface side of the suspension mounting bracket, and the membrane member is fixed to the front side member, the vertical member, and the suspension mounting bracket, respectively. Vehicle front structure.   The vehicle front portion structure according to claim 4 or 5, wherein a weak portion is provided in the outer member.   6. A radio core upper for fixing an upper portion of a radiator is attached to an upper portion of the vertical member, and a rear portion of the vertical member is connected to a hood ridge via a radio core side member. Vehicle front structure as described.   The vehicle front part structure according to any one of claims 1, 2, 4, and 5, wherein the film member includes carbon fiber.   The vehicle front structure according to any one of claims 1, 2, 4, and 5, wherein the film member includes an aramid fiber. The vehicle front structure according to any one of claims 1, 2, 4, and 5, wherein the film member is fixed by spot welding.

Images