JP6254858B2 - Vehicle front structure - Google Patents

Description

  The present invention relates to a vehicle body front structure including a pair of left and right front side frames protruding from the front of a cabin toward the front side of the vehicle and a cradle frame attached to a lower portion of the front side frame.

  2. Description of the Related Art In recent years, various improvements have been made in collision safety of automobiles and the like, and it has been desired to improve safety against offset collision in which a vehicle partially collides with an obstacle in a vehicle body structure. In particular, in recent years, among offset collisions, there has been a demand for improved performance against so-called small overlap collisions in which an obstacle collides only with an end in the vehicle width direction of the vehicle.

  As a technique for such a small overlap collision, for example, Japanese Patent Application Laid-Open No. 2013-221757 is provided with a gusset that protrudes outward in the vehicle width direction from the front side frame, and the front end of the gusset is defined as a crash can in the vehicle longitudinal direction. It is arranged at the same position or rear side as compared with the connecting part with the front side frame, and the side surface on the outer side in the vehicle width direction of the gusset is formed so as to incline in the vehicle width direction toward the rear of the vehicle body in plan view, A technique of a vehicle body front structure in which a gusset and a power unit are overlapped in the vehicle longitudinal direction is disclosed.

JP 2013-212757 A

  The gusset disclosed in Patent Document 1 described above is used as an energy absorbing member when colliding only with the outside of the front side frame. The gusset receives the collision load input from the bumper beam, and the engine is connected via the front frame. The block is used as a reaction member to absorb collision energy.

  However, even if it collides only on the outside of the front side frame, the front side frame gusset alone does not always sufficiently absorb the collision energy, and the front wheels etc. located outside the engine block collide and enter the cabin. There is a risk of doing. For this reason, it is necessary to reinforce the cabin itself, which not only causes a significant increase in vehicle weight and cost, but also impairs running performance and fuel consumption performance. On the other hand, if the collision energy absorption performance is increased, the vehicle body may be deformed even if it is a slight collision, and the cost required for repair is generated and becomes a burden on the user.

  The present invention has been made in view of the above circumstances, and improves collision energy absorption performance in response to a small overlap collision, while in the case of a minor collision, a vehicle that can suppress vehicle body deformation damage. The object is to provide a front body structure.

A vehicle body front structure according to the present invention includes a pair of left and right front side frames protruding from a cabin front to the vehicle front side, and a cradle frame attached to a lower portion of the front side frame. A side frame gusset for transmitting a collision load input from the front side of the vehicle to the front side frame is provided on the front side portion of the front side frame and input from the front side of the cradle frame from the front side of the vehicle. A cradle gusset for transmitting a collision load to the cradle frame is provided , and the cradle gusset is extended from the upper surface of the cradle frame to a region outside in the vehicle width direction and is expanded to the outside in the vehicle width direction toward the front. And the width of the vehicle from the bottom surface of the cradle frame A lower surface portion that extends outward and is joined to the upper surface portion, and a front surface side of the cradle frame that closes a front opening between the upper surface portion and the lower surface portion, and inputs the collision load. In the case of a small overlap collision, the front part becomes a main part that receives an impact load in contact with an obstacle in a larger area, and is thicker than the upper surface part and the lower surface part. ing.

  According to the present invention, the collision energy absorption performance can be improved in response to the small overlap collision, while the deformation damage of the vehicle body can be suppressed in the case of a slight collision.

Schematic plan view of the front body structure as seen from above the vehicle The perspective view which looked at the front part structure of the body from the upper rear side outside the vehicle width direction Explanatory drawing which shows arrangement of side frame gusset and cradle gusset Perspective view of side frame gusset and cradle gusset from below Perspective view of cradle gusset viewed from above Explanatory drawing showing the action of the side frame gusset at the time of small overlap collision Explanatory drawing showing the action of the cradle gusset during a small overlap collision

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2, reference numeral 1 denotes a front portion of a vehicle. The vehicle front portion 1 includes an engine 10, a transmission 20, a cabin 30, a front side frame 40, a radiator panel 50, a bumper beam 60, and a cradle frame 70. A front wheel 80, a front suspension 90, and the like are provided.

  As an example, the engine 10 is a horizontally opposed four-cylinder gasoline or diesel engine mounted vertically, and is provided at the end of a cylinder block (a side end of the engine 10) arranged on the left and right with the crankshaft in between. The cylinder head is provided.

  The transmission 20 includes a starting device such as a torque converter or a clutch, a transmission device such as a CVT variator or a transmission gear train, an AWD transfer that distributes driving force to the front and rear wheels, and a final deceleration. A device, a front differential, etc. are accommodated.

  The cabin 30 is a portion that is provided at the center of the vehicle and on which an occupant rides. The cabin 30 includes a floor panel 31, a toe board 32, a floor tunnel 33, an A pillar 34, a side sill 35, and the like.

  The floor panel 31 is a substantially planar portion constituting the floor surface of the cabin. The toe board 32 is a surface portion that is arranged to rise upward from the front end portion of the floor panel 31 and constitutes a front surface portion (a partition wall portion between the cabin 30 and the engine room) of the cabin 30.

  The floor tunnel 33 is formed by projecting the center portion of the floor panel 31 in the vehicle width direction upward (toward the vehicle interior side), and accommodates a rear portion of the transmission, a propeller shaft, an exhaust pipe, and the like.

  The A pillar 34 is a columnar structural member that protrudes upward from the front end portion of the left and right side end portions of the floor panel 31, and the side sill 35 extends from the lower end portion of the A pillar 34 to the vehicle rear side. It is a beam-like structural member arranged along the side end of the panel 31.

  The front side frame 40 is a structural member disposed so as to protrude from the toe board 32 of the cabin 30 toward the front side of the vehicle. The front side frame 40 is provided with a pair of left and right sides of the engine 10 and a surface portion on the inner side in the vehicle width direction. Is disposed to face the side surface of the engine 10 (in the case of a horizontally opposed engine, a tappet cover of a cylinder head) with a space therebetween. Further, the front side frame 40 has a closed cross section in which the cross sectional shape viewed from the vehicle front-rear direction is substantially rectangular.

  The radiator panel 50 is a frame-like structure that supports the radiator core C that cools the cooling water of the engine 10, the condenser of the air conditioner, and the like, and is disposed in front of the engine 10. Further, the side end portion of the radiator panel 50 is fixed in the vicinity of the front end portion of the front side frame 40.

  The bumper beam 60 is provided inside a bumper face (not shown) that is an exterior part provided at the front end of the vehicle body, and is formed in a beam shape extending substantially along the vehicle width direction. It is transmitted to the receiving vehicle rear side. The bumper beam 60 is formed in a curved arc shape with a convex front side in accordance with the formation of the bumper face, and has a base 61 that protrudes from the rear surface, and the rear end of the base 61 is The front side frame 40 is fixed to the front end portion.

  The cradle frame 70 is a subframe attached to the lower part of the front side frame 40, and is a structural member on which various components are mounted. An engine mount (not shown) that supports the engine 10, a lower arm 92 of the front suspension 90, and the like are attached to the cradle frame 70. The cradle frame 70 is formed in, for example, a rectangular frame shape, and is fixed to the vehicle body by attaching attachment portions provided on the front and rear sides to the front side frame 40 via a bracket 150 disposed in the vertical direction.

  The front wheel 80 is a front wheel of a vehicle configured by mounting a tire on a rim made of, for example, an aluminum alloy. The front wheel 80 is rotatably supported by a hub bearing housing (not shown) and can be steered by pushing and pulling a tie rod T disposed in front of the axle.

  The tie rod T is coupled to a steering gear box (none of which is shown) connected to a steering wheel via a steering shaft, and is driven substantially along the vehicle width direction in accordance with the steering operation of the driver. In FIGS. 1 and 2, the tire is not shown.

  The front suspension 90 supports a hub bearing housing that supports the front wheel 80 so as to be swingable with respect to the vehicle body. The front suspension 90 is, for example, a McPherson strut type, and includes a strut 91 and a lower arm. 92 and the like.

  The strut 91 (see FIG. 2) is provided between a strut upper mount 93 provided on the upper side of the engine compartment of the vehicle body and a bracket (not shown) provided on the upper portion of the hub bearing housing. The strut 91 is a shock absorber (damper) and a spring unitized.

  Further, as shown in FIGS. 2 to 4, the front side frame 40 and the cradle frame 70 of the vehicle front portion 1 are each provided with a side as a load transmission unit that transmits a collision load from an obstacle at the time of a small overlap collision. A frame gusset 100 and a cradle frame 200 are provided. 2 to 4 show an example in which the position of the front end portion of the cradle gusset 200 is arranged behind the front end portion of the side frame gusset 100 (cabin 30 side), but as will be described later. The position of the tip of the cradle gusset 200 may be aligned with the bumper beam 60.

  When the front end portion of the cradle gusset 200 is arranged behind the front end portion of the side frame gusset 100, as shown by a broken line in FIG. 3, the front portion of the cradle gusset 200 below the bumper face (not shown) Can be used as a mounting portion for mounting an in-vehicle component such as the fog lamp 300, and both the mounting strength and the mounting space of the in-vehicle component can be ensured.

  The side frame gusset 100 is disposed in a region outside the vehicle width direction in the vicinity of the front end portion of the front side frame 40. The side frame gusset 100 is formed in a beam shape having a closed cross section, and is inclined to open forward with respect to the vehicle longitudinal direction so that the front end portion 101 is on the outer side in the vehicle width direction with respect to the rear end portion 102. (The diameter is increased in the vehicle width direction toward the front).

  The front end portion 101 of the side frame gusset 100 is disposed so that the front end surface 101 a thereof is opposed to the rear surface 60 a of the bumper beam 60 with a spacing portion 110. The front end portion 101 of the side frame gusset 100 is supported by a stay 103 that protrudes outward from the front side frame 40 in the vehicle width direction.

  Further, the rear end portion 102 of the side frame gusset 100 is fastened and fixed to a side surface portion of the front side frame 40 on the outer side in the vehicle width direction by, for example, a bolt inserted from the outer side in the vehicle width direction. The position of the rear end portion 102 of the side frame gusset 100 in the vehicle front-rear direction is arranged on the vehicle front side of the center of the engine 10 in the front-rear direction.

  Further, the rear surface 60a of the bumper beam 60 has a relative position of the front end surface 101a of the side frame gusset 100 with respect to the rear surface 60a of the bumper beam 60 toward the upper surface of the side frame gusset 100 behind the front end surface 101a of the side frame gusset 100. An upper guide member 120 that is long and wide in the vehicle width direction is provided to restrict the upward movement.

  Furthermore, relative to the rear surface 60a of the side frame gusset 100 relative to the rear surface 60a of the bumper beam 60, the rear surface 60a of the bumper beam 60 faces the lower surface of the side frame gusset 100 behind the front end surface 101a of the side frame gusset 100. The lower guide member 130 that is long and wide in the vehicle width direction is provided to restrict the downward movement.

  Further, on the rear surface 60a of the bumper beam 60, the front end of the side frame gusset 100 with respect to the rear surface 60a of the bumper beam 60 is directed toward the outer side in the vehicle width direction of the side frame gusset 100 behind the front end surface 101a of the side frame gusset 100. A side guide member 140 that is long and wide in the vertical direction is provided to restrict the movement of the surface 101a in the relative outward direction.

  These guide members 120, 130, and 140 are provided so as not to contact the front end portion 101 of the side frame gusset 100. That is, even when the bumper beam 60 rotates during the small overlap collision, the front end surface 101a of the side frame gusset 100 is surrounded by the guide members 120, 130, and 140 on the rear surface 60a of the bumper beam 60. It is relatively maintained within a predetermined region, and the rear surface 60a of the bumper beam 60 and the front end surface 101a of the side frame gusset 100 are reliably brought into contact with each other so that they can play a sufficient role.

  A separator 41 (see FIG. 1) is provided in the front side frame 40 in the vicinity of the fixed portion of the rear end portion 102 of the side frame gusset 100 so as to partition the internal cross section of the front side frame 40 and substantially close it. . In addition, the front side frame 40 is bent in a region adjacent to the rear side of the fixed portion of the rear end portion 102 of the side frame gusset 100 on the side surface portion on the outer side in the vehicle width direction of the front side frame 40 when a small overlap collision occurs. A bead 42 as a starting point is formed.

  On the other hand, the cradle gusset 200 is arranged in the vehicle width direction outside region at the front end corner portion of the cradle frame 70 so as to expand outward in the vehicle width direction as it goes forward. The cradle frame 70 includes a side member 71 having a substantially rectangular cross-sectional shape provided below the left and right front side frames 40, a cross beam-shaped front member 72 disposed on the lower rear side of the bumper beam 60, A curved connecting portion 73 that connects the member 71 and the front member 72 is provided.

  A tie-down hook 74 for fixing the vehicle body when the vehicle is loaded is fixed in the vicinity of the connection portion of the side member 71 to the connecting portion 73, and a portion in front of the tie-down hook 74 is a small portion. This is a starting point for bending the cradle frame 70 at the time of an overlap collision. The cradle gusset 200 is disposed in a connecting portion 73 that is a front end corner portion of the cradle frame 70, and efficiently transmits a collision load to the connecting portion 73 at the time of a small overlap collision, while at the time of a full wrap collision from the front of the vehicle, The front side frame 40 is configured not to impede the collision energy absorption.

  As shown in FIG. 5, the cradle gusset 200 includes an upper surface portion 201 that extends outward in the vehicle width direction from the upper surface of the connecting portion 73, and an upper surface portion 201 that extends outward in the vehicle width direction from the lower surface of the connecting portion 73. It has a lower surface portion 202 to be joined and a front surface portion 203 that is disposed on the front member 72 side of the cradle frame 70 and closes the front opening of the upper surface portion 201 and the lower surface portion 202. In the present embodiment, the cradle gusset 200 has a three-piece structure in which an upper surface portion 201, a lower surface portion 202, and a front surface portion 203 are formed by sheet metal processing, and a bolt or the like is connected to the connecting portion 73 of the cradle frame 70. Are bound by.

  The cradle gusset 200 may be coupled to the connecting portion 73 by welding instead of bolting. Further, the cradle gusset 200 may be formed as one component in which the upper surface portion 201, the lower surface portion 202, and the entire surface portion 203 are integrally formed, and further formed integrally with the connecting portion 73 of the cradle frame 70. You may do it.

  The upper surface portion 201 of the cradle gusset 200 is formed in a shape having a projection surface on the road surface side of a substantially triangular shape that extends to an outer region in the vehicle width direction of the connecting portion 73 and expands outward in the vehicle width direction toward the front. Has been. The portion having the substantially triangular projection surface is formed by a plurality of ridge lines 204 extending substantially in the front-rear direction from the attachment surface 201 a to the upper surface of the connecting portion 73 to the mating surface 201 b in contact with the lower surface portion 202. It has a terrace. The lower surface portion 202 has substantially the same outer shape as the upper surface portion 201, but a terrace portion like the upper surface portion 201 is not necessarily provided (see FIG. 4).

  The front surface portion 203 is formed as a lid-like member that covers the opening on the front surface when the upper surface portion 201 and the lower surface portion 202 are combined, and is joined to the front end sides of the upper surface portion 201 and the lower surface portion 202 by welding or the like. Yes. The front surface portion 203 is a main portion that contacts an obstacle over a larger area and receives a collision load during a small overlap collision. For this reason, the front surface portion 203 is thicker than the upper surface portion 201 and the lower surface portion 202, and, as shown in FIG. 5, reinforcing ribs 203a and 203b are provided.

  As described above, the cradle gusset 200 receives the collision load at the front surface portion 203 having a larger area, disperses the stress of the collision load by the substantially triangular shape of the upper surface portion 202, and is formed by the ridgeline 204 in the front-rear direction. A gusset structure that is difficult to deform is realized by securing the rigidity against the collision load by the terrace.

  Next, the operation of the side frame gusset 100 and the cradle gusset 200 during the small overlap collision of the vehicle front portion 1 will be described.

  As shown in FIG. 6, the obstacle B that collides with the vehicle approaching from the front side is disposed outside the front end portion of the front side frame 40 at the center portion in the vehicle width direction. . The obstacle B is, for example, a cylindrical shape imitating a pole such as a utility pole or a traffic light. When the obstacle collides with a side portion of the bumper beam 60, the bumper beam 60 is connected to the front side frame 40 via the base 61. Compressive load in the axial direction is transmitted.

  Further, the bumper beam 60 is bent and deformed in a direction in which the side end portion is retracted in a region outside the base portion 61. As a result, the rear surface 60 a of the bumper beam 60 abuts on the front end surface 101 a of the front end portion 101 of the side frame gusset 100 and transmits an axial compressive load to the side frame gusset 100.

  The load from the side frame gusset 100 acts to be pushed inward in the vehicle width direction with respect to the side surface portion of the front side frame 40 via the rear end portion 102 of the side frame gusset 100. By this pushing load, the front side frame 40 starts bending deformation in a direction in which the front side is displaced inward in the vehicle width direction with the periphery of the bead 42 as the starting point of the folding. When the amount of deformation is greater than or equal to a predetermined amount, the cylinder 10 (a tappet cover) that is a portion facing the front side frame 40 in the engine 10 comes into contact.

  When the amount of relative backward movement of the obstacle with respect to the vehicle body (the amount of relative forward movement of the vehicle body with respect to the obstacle) is further increased, the amount of deformation of the front side frame 40 toward the inside in the vehicle width direction is further increased. 10 is pressed and displaced to the opposite side in the vehicle width direction (side not colliding with the obstacle B). At this time, the uncompressed region at the front end portion of the front side frame 40 promotes the pushing of the engine 10 outward in the vehicle width direction by the axial force.

  As described above, when the heavy engine 10 is pushed to the opposite side in the vehicle width direction, the vehicle changes its direction to avoid the obstacle, and the A pillar 34 of the cabin 30, the side sill 35, etc. The transmission load to is reduced. Further, the front side frame 40 itself exhibits a function of absorbing energy by the bending deformation described above.

  At this time, a collision load is input to the front surface portion 201 of the cradle gusset 200 at a timing corresponding to the position with respect to the bumper beam 60. The cradle gusset 200 has a strong rigidity due to a terrace portion formed by a plurality of ridge lines 204 extending in the front-rear direction so as not to be easily deformed by a collision load, and is input from the front surface portion 201. The load is transmitted to the connecting portion 73 of the cradle frame 70.

  As a result, as shown in FIG. 7, the cradle frame 70 is bent so that the connecting portion 73 is pushed inward in the vehicle width direction, starting from a portion in front of the tie-down hook 74. The front tire (front wheel 80) can be rotated in the toe-in direction on the engine 10 side through the front suspension 90 and the tie rod T by the bending deformation of the cradle frame 70 toward the inner side in the vehicle width direction. While absorbing the collision energy by a tire, the attack by the collision of the front wheel 80 to the cabin 30 can be avoided.

  In this case, when the position of the front surface portion 201 of the cradle gusset 200 is aligned with the same position as the bumper beam 60, the side frame gusset 100 and the cradle gusset 200 receive a collision load at substantially the same timing. As a result, the front side frame 40 and the cradle frame 70 can be deformed without interfering with each other, and the collision energy can be efficiently absorbed by both the front side frame 40 and the cradle frame 70. In addition, since the side frame gusset 100 and the cradle gusset 200 receive a collision load, in the case of a slight collision, the deformation damage degree of the vehicle body can be minimized, and the cost required for repair can be suppressed. .

  On the other hand, when the position of the front surface portion 201 of the cradle gusset 200 is arranged so as to be retracted from the bumper beam 60, the collision load is transmitted from the side frame gusset 100 to the front side frame 40 when transmitted to the vehicle body rear side. The load can be transmitted from the cradle gusset 200 to the cradle frame 70 when the load is reduced. In other words, by transmitting the entire collision load to the rear side of the vehicle at a different timing, it is possible to make the load input close to a rectangular wave and efficiently absorb the collision energy.

  As described above, in the embodiment of the present invention, the front frame of the front side frame 40 is provided with the side frame gusset 100 that transmits the collision load input from the front side of the vehicle to the front side frame 40, and the front side frame 40. A cradle gusset 200 for transmitting a collision load input from the front side of the vehicle to the cradle frame 70 is provided on the front side portion of the cradle frame 70 attached to the lower portion of the side frame 40. An upper surface portion 201 that extends to the outer region in the width direction and expands outward in the vehicle width direction toward the front, and extends outward in the vehicle width direction from the lower surface of the cradle frame 70 and is joined to the upper surface portion 201. Arranged on the lower surface 202 and the front side of the cradle frame 70 It is, has a strong structure formed by a front portion 203 for inputting blocked by collision load to the front opening between the upper surface portion 201 and the lower surface portion 202.

  As a result, in the case of a small overlap collision, both the side frame gusset 100 and the cradle gusset 200 receive a collision load and transmit it to the rear side of the vehicle body. Is pushed to the opposite side in the vehicle width direction, and the front wheel 80 outside the front side frame 40 is rotated in the toe-in direction by bending deformation of the cradle frame 70 to effectively absorb the collision energy and reduce the collision damage of the cabin 30. Thus, the protection performance can be improved. On the other hand, in the case of a minor collision, the side frame gusset 100 and the cradle gusset 200 receive a collision load to minimize the deformation damage degree of the vehicle body, and the cost required for repair can be suppressed.

DESCRIPTION OF SYMBOLS 1 Vehicle front part 10 Engine 20 Transmission 30 Cabin 31 Floor panel 32 Toe board 33 Floor tunnel 34 A pillar 35 Side sill 40 Front side frame 60 Bumper beam 70 Cradle frame 80 Front wheel 90 Front suspension 91 Strut 92 Lower arm T Tie rod 100 Side frame gusset 200 Cradle gusset 201 Upper surface portion 202 Lower surface portion 203 Front surface portion 204 Ridge line 300 Fog lamp (on-vehicle component)

Claims (5)

In a vehicle body front structure comprising a pair of left and right front side frames protruding from the front of the cabin to the front side of the vehicle, and a cradle frame attached to the lower part of the front side frame,
While providing a side frame gusset for transmitting a collision load input from the front side of the vehicle to the front side frame on the front side portion of the front side frame,
A cradle gusset for transmitting a collision load input from the front side of the vehicle to the cradle frame on the front side portion of the cradle frame is provided .
The cradle gusset,
An upper surface portion that extends from the upper surface of the cradle frame to a region outside in the vehicle width direction and that expands outward in the vehicle width direction toward the front;
A lower surface portion that extends outward in the vehicle width direction from the lower surface of the cradle frame and is joined to the upper surface portion;
It is arranged on the front side of the cradle frame, and comprises a front part for closing the front opening between the upper surface part and the lower surface part and inputting the collision load,
The front part is a main part that receives an impact load by contacting an obstacle in a larger area at the time of a small overlap collision, and is thicker than the upper surface part and the lower surface part. Vehicle front structure. The vehicle body front part structure according to claim 1, wherein the cradle gusset is provided with a plurality of ridge lines extending in the front-rear direction. The front part of the cradle gusset is arranged at a position where the collision load can be transmitted to the cradle frame at the same timing as the transmission timing of the collision load from the side frame gusset to the front side frame. Item 3. The vehicle body front structure according to Item 1 or 2 . The front portion of the cradle gusset is disposed at a position where the collision load can be transmitted to the cradle frame at a timing delayed from the transmission timing of the collision load from the side frame gusset to the front side frame. The vehicle body front part structure according to claim 1 or 2 . 5. The vehicle body front structure according to claim 4 , wherein a front portion of the cradle gusset is disposed rearward of a front end portion of the side frame gusset, and an in-vehicle component is disposed in front of the cradle gusset. .

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