JP3448882B2 - Frame and car body structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body structure including a frame formed by joining a plurality of panels to each other to form a closed cross section, and the frame arranged on the left and right sides of the vehicle body in the front-rear direction.

[0002]

2. Description of the Related Art Conventionally, in order to ensure the rigidity of a vehicle body of an automobile, a frame extending in the vehicle body longitudinal direction is provided on both sides of the vehicle body, and a front side frame extending to the engine room side portion at the front of the vehicle body has a plurality of panels. Formed in a closed cross section where members are joined together to support the engine, etc. through the front cross member, etc., and to prevent the engine from retreating when subjected to a longitudinal impact load such as a head-on collision, etc. By buckling and deforming in a pattern, the impact is absorbed and the influence on the occupants in the vehicle compartment is reduced.

The closed cross-sectional shape of the front side frame described above is, for example, as shown in Japanese Utility Model Laid-Open No. 2-24777, a substantially U-shaped cross section, and is located inside the vehicle body having a flange portion that extends outward at the open end. An inner panel and an outer panel located outside the vehicle body that is joined to the flange portion to cover the open side of the inner panel, is formed in a substantially rectangular cross section, and is subjected to buckling deformation in a predetermined deformation pattern,
The bead is provided at a predetermined position where it is buckled and deformed.

[0004]

However, in the above-mentioned conventional frame, since the step of providing the bead at the buckling deforming portion is indispensable, the manufacturing process becomes complicated and the buckling deforming is performed in a predetermined deformation pattern. There is a problem in that it is difficult to design the shape of the bead and the spot welding position required in order to increase the manufacturing cost. Further, since the engine or the like is supported, it is necessary to secure the rigidity of the portion other than the portion where the bead is provided and which is buckled and deformed, and there is a problem that an increase in weight cannot be avoided.

An object of the present invention is to change the strength of rigidity of the frame itself in the longitudinal direction with a simple structure to surely absorb the shock due to buckling deformation in a predetermined deformation pattern, and
To provide a frame provided with a frame capable of reducing the weight of a vehicle body and a vehicle body structure of an automobile.

[0006]

In order to achieve the above object, a frame and a vehicle body structure of the present invention are formed by joining two panels of an outer panel and an inner panel to form a polygonal cross section, and a vehicle longitudinal direction. In the vehicle body structure of an automobile including a front side frame having a shock absorption portion and a shock resistant portion, the positions of joint flanges extending in the frame longitudinal direction on the upper and lower surfaces of the frame at the joint portion of both panels Frame width direction according to the direction position
By displacing outward or changing the cross-sectional shape according to the position in the longitudinal direction of the frame, the number of bent portions in the cross-sectional shape is increased or decreased according to the position in the longitudinal direction of the frame, and the rigidity of the frame is changed to the position in the longitudinal direction of the frame. It is different according to. In addition, it has a shock-absorbing portion that buckles and absorbs a shock and a shock-resistant portion that does not deform to increase the rigidity of the frame in the shock-absorbing portion and reduce the rigidity of the frame in the shock-resistant portion. The rigidity is secured by joining another member to the impact site.

[0007]

1 to 4, a frame 1 is formed by joining an inner panel 2 located inside the vehicle body and an outer panel 3 located outside the vehicle body. The frame width H is defined as the distance between the inner bottom surface of the inner panel 2 and the inner bottom surface of the outer panel 3 that face each other across the joint. The inner panel 2 is open toward the outside of the vehicle body, is formed into a substantially U-shaped cross section, and has a bottom portion 2b and a pair of side wall portions 2c and 2c, and a main body portion 20, an open end of the main body portion 20, that is, a side wall portion. A pair of flanges 2a, 2a extending outward at the tips of 2c, 2c (that is, the outer ends of the vehicle body)
Is formed from the inner surface of the bottom portion 2b to the side wall portion 2c.
The inner panel width h _i is the dimension up to the tip of. Also,
The outer panel 3 is open toward the inside of the vehicle body and has a main body portion 20 having a bottom portion 3b and a pair of side wall portions 3c and 3c formed in a substantially U-shaped cross section, and an open end of the main body portion 20, that is, the side wall portion 3c. , 3c is formed from a pair of flanges 3a, 3a extending outward at the tips (that is, the inner ends of the vehicle body),
The dimension from the inner surface of the bottom portion 3b to the tip of the side wall portion 3c is defined as the outer panel width h _O. The inner panel 2 and the outer panel 3 are joined to each other by joining the flanges 2a and 3a by spot welding or the like so that the open sides of the cross sections are aligned with each other to form a joint flange 1a extending in the frame longitudinal direction to form the frame 1.

The sum of the inner panel width h _i of the inner panel 2 and the outer panel width h _O of the outer panel 3 is held at H (h
_i + h _O = H), while continuously changing the inner panel width h _i in the range from 0 to H (0 ≦ h _i ≦ H), the outer panel width h _O from 0 to H (0
By continuously changing at ≦ h _O ≦ H), in which connection flange 1a of the flange 2a and 3a are joined is formed by shifting the position in the width direction along the longitudinal direction of the frame 1, this embodiment In the example, the inner panel width h _i is H / 2 ≦
h _i ≦ H, the outer panel width h _O is 0 ≦ h _O ≦ H / 2, and the joint flange is formed in the center of the frame 1 at the position shown in FIG. 3 (see FIG. 1). For example,
If the outer panel width h _O = 0, the inner panel width h _i
= H, and the outer panel 3 and the side wall portion 3c, 3c are exhausted becomes flat (see FIG. 2), it positioned closest to the vehicle body outer flange 1a is also equal to the outer panel width h _O and the inner panel width h _i , H _O = h _i = H / 2, the joint flange 1a is located at the center of the frame 1 (FIG. 3).
reference).

According to the structure described above, in the cross section in which the joint flange shown in FIG. 2 is located at the end of the frame 1, the bent portion of the inner panel 2 has a bottom portion 2b and a side wall portion 2.
There are four connecting portions 2d and 2d of c and 2c and connecting portions 2e and 2e of the side wall portions 2c and 2c and the flanges 2a and 2a, and the bending portion of the outer panel 3 is zero. The number of copies is four. On the other hand, in the cross-section where the joint flange 1a shown in FIG. 3 is displaced from the end of the frame 1, the bent portion of the inner panel 2 has the bottom portion 2b and the connecting portions 2d, 2d of the side wall portions 2c, 2c. , Side wall portions 2c, 2
There are four connecting parts 2e, 2e of c and the flanges 2a, 2a, and the bent part of the outer panel 3 includes a bottom part 3b and a side wall part 3.
Since there are four connecting portions 3d and 3d of c and 3c and connecting portions 3e and 3e of the side wall portions 3c and 3c and the flanges 3a and 3a, the total number of bent portions is eight.

In the hollow frame, the greater the number of bent portions in the cross section, that is, the greater the number of ridges, the greater the strength and rigidity of the frame. Therefore, the frame 1 is shown in FIG. The part with a different cross-sectional shape is
It is possible to provide greater strength than the portion having the cross-sectional shape shown in FIG. 2, and by changing one of the flanges 1a, in the longitudinal direction of the frame 1,
Strength and rigidity can be changed depending on the position.

The outer panel 3 is provided at a portion where the joint flange 1a is displaced from the end of the frame 1 toward the center.
By inclining the upper side wall portion 3c of the so as to open toward the open side, that is, the inner panel 2 side, a space can be secured above the frame 1, and spot welding can be easily performed. Flange 1a is frame 1
There are those that are inclined over the entire area that is deviated from the end part to the center direction, and those that are formed by cutting only the spot welding position to form multiple notch recesses. In the latter, use the notch recesses as crushed beads. You can Especially when it is used as a crushed bead, not only the upper side wall portion 3c of the outer panel 3 but also the lower side wall portion 3c may be provided with a plurality of notch recesses at positions corresponding to the upper side wall portion 3c. On both side wall portions 2c, 2c, a plurality of cutout recesses are provided corresponding to the intermediate positions of the adjacent cutout recesses provided on the outer panel 3, that is, the cutout recesses provided on the inner panel 2 and the outer panel. By arranging the notch recesses provided in 3 in a staggered manner, it is possible to reliably cause buckling deformation and absorb the shock when a load in the longitudinal direction is received.

To explain the above-mentioned structure in detail, as shown in FIG. 5, in the frame 1 having a rectangular cross section, the upper flange 21a of the inner panel 2 and the upper flange 31a of the outer panel 3 may be inclined toward the outer panel 3 side. By doing so, the inner panel width h _i of the inner panel 2
= H, that is, the cross section at the position where the joint flange is formed at the end of the frame 1, one bent portion of the upper flange 21a of the inner panel 2 and one bent portion of the upper flange 31a of the outer panel 3 are provided, and the total is 2 You can increase the number. Further, as shown in FIG. 6, the joint flange 1a
In the frame 1 which is located at a position deviated from the end of the frame 1 toward the center, the flange 1a on the upper surface is inclined outward and the upper side wall portion 31b of the outer panel 3 is inclined outward, so that A space can be secured, and spot welding work can be easily performed. Further, as shown in FIG. 7, in the frame 1 in which the joint flange is displaced from the end of the frame 1 toward the center, the flange 1a is inclined outward, and spot welding of the upper side wall portion 31b of the outer panel 3 is performed. By providing the notched recesses 31c inclining to the outside corresponding to the positions where the welding is performed, a space can be secured above the frame 1, so that the spot welding work is facilitated and when the compression deformation is performed in the axial direction. In addition, the notch recess 31c at the spot welding position has an effect as a crushed bead.

Further, although the frame 1 has a rectangular cross section in the above embodiment, it is not limited to a rectangular cross section but may have a polygonal cross section such as a pentagon, hexagon, octagon, etc. , The bottom portion 3b of the outer panel 3
May be formed into a pentagonal shape (see FIG. 8) by protruding in a mountain shape toward the outside of the vehicle body.

In the above-described embodiment, the upper joining flange and the lower joining flange are provided at the same position, but they may be provided at different positions. By arranging the lower joint flange to be offset from each other, it is possible to secure a portion for fixing the member on the upper surface or the lower surface of the frame, and also to maintain a large strength. Also, by changing the cross-sectional shape of the frame, it is possible to control the axial compression. For example, the cross-sectional cup shape that expands to the outer panel side is adopted as the basic cross-sectional shape of the inner panel. By suppressing the back amount and improving the workability, the surface accuracy of the required portion can be obtained by making only the portion where the horizontal surface is required on the upper surface or the lower surface of the mounting portion of the member, or the upper and lower surfaces.

Next, an example of a frame and a vehicle body structure using the above frame structure as a front side frame will be described. In FIG. 9, front side frames 10 and 10 extending in the vehicle front-rear direction are arranged on both sides in an engine room 13 defined by a dash panel 12 in front of the vehicle body 11, and front ends of the front side frames 10 and 10 extend in the vehicle width direction. Is joined to a front cross member 14 extending to the front side frame 10, which is joined to a wheel apron 15 forming a vehicle body side wall in the engine room 13 and a suspension cross member 16 extending in the vehicle body width direction. The rear end of 10 is joined to the tip of the floor frame under the floor panel. Reference numeral 17 is a suspension tower, and 18 is an engine member in which front and rear ends are joined to a front cross member 14 and a suspension cross member 16.

Front side frame 10 having joint flanges 101 extending in the longitudinal direction (front and rear direction of the vehicle body) on the upper and lower surfaces
(Only the right side is shown in FIG. 10 as an example), the side end of the front cross member 14 is sequentially rearward from the front end portion 10A joined to the lower surface and the inside surface of the vehicle body, and is subjected to a buckling deformation due to an impact in the front-rear direction to cause an impact. The shock absorbing portion 10B for absorbing, the engine mount portion 10C where the engine mount bracket 19 is mounted in contact with the upper surface and the inside surface of the vehicle body, and the wheel apron joint portion where the wheel apron 15 is joined to the joint flange 101.
10D, a shock-resistant portion such as a cross-member mounting portion 10E to which the suspension cross member 16 is joined to the lower surface, which does not buckle and deform, and a rearward extending portion 10F (impact-resistant portion) that penetrates the dash panel 12 are formed. Has been done.

The cross-sectional shapes of the tip portion 10A, the engine mount portion 10C, the wheel apron joint portion 10D, and the cross member attachment portion 10E, which are shock resistant portions, are the outer panel width h _O = 0,
The inner panel width h _i = H, that is, the outer panel 3 is a flat plate, and the joint flange 101 is located at the outermost side of the vehicle body (see FIGS. 1 and 2). On the other hand, the impact absorbing portion 10B has a sectional shape in which the outer panel width h _O is equal to the inner panel width h _i, and h _O = h _i = H / 2 is set so that the joint flange 101 is located at the center of the frame 1 and the rigidity is maximized. (See FIG. 3). That is, when the frame 1 receives an axial impact, it undergoes buckling deformation to absorb the impact.
The cross-sectional shape of 10B has a high rigidity, and the cross-sectional shape of the impact resistant portion requiring other strength is a low rigidity.

As described above, according to the frame and the vehicle body structure of the present invention, the rigidity of the shock absorbing portion 10B, which should originally be liable to be buckled and deformed, cannot be changed to the other shock resistant portion (cross member mounting portion).
10E) and other parts are joined together, and the portion that does not undergo buckling deformation, which originally requires rigidity, is secured by the other members joined. For example, in the engine mount portion 10C, By fixing the mount bracket 19 to the upper surface (see FIG. 11) and joining the suspension cross member 16 to the lower surface at the cross member attachment portion 10E (see FIG. 12), the suspension cross member 16
This ensures sufficient rigidity. In addition, the change in the rigidity of the frame may be used in combination with the change in the cross-sectional shape by using a polygon having a pentagonal shape or more as a highly rigid portion. According to the above structure, the rigidity of the shock absorbing portion is made larger than that of the shock resistant portion, and the shock resistant portion is increased in rigidity by the member joined thereto, thereby lowering the rigidity of the front side frame itself as a whole. It is possible to reduce the thickness of the front side frame, and it is possible to promote weight reduction.

In the above embodiment, the upper and lower joining flanges 101 are aligned in the width direction, but when only one of the upper surface and the lower surface is used when joining other members in the impact resistant portion. The (tip portion 10A, engine mount portion 10C) is a surface (tip portion 10) where members (front cross member 14, engine mount bracket 19) are joined.
Only the joint flange 101 of the lower surface in A and the upper surface in the engine mount portion 10C) is displaced from the center to the outer end in the width direction ( _ho = 0) to secure the member mounting area, and the other surface (tip portion 10A).
Then, by arranging the joint flange 101 at the center on the upper surface and on the lower surface in the engine mount portion 10C), the rigidity of the shock resistant portion can be improved. Also the frame
When the width of 10 is sufficient, the displacement amount of the joint flange 101 on the surface where the members of the impact resistant portion are joined is set as a necessary amount for securing the joint area, and the joint flange 101 is set to the outermost end in the width direction ( _ho = Outer panel width h _o >
The rigidity of the impact resistant portion may be increased by providing it at the upper surface position where the rigidity is increased, or the rigidity may be increased by changing the cross-sectional shape of the impact resistant portion. . Further, the rigidity of the impact resistant portion can be increased by inclining the joining flange 101 outward of the vehicle body (see reference numeral 1a in FIG. 5).

At the wheel apron joint 10D,
The wheel apron 15 is joined to the joining flange 101 on the upper surface, and the joining flange 101 is joined to the outermost end in the width direction (h
by the case of providing the _o = 0) it tilts the joint flange 101 on the outside of the vehicle body (reference numeral 1a in FIG. 5), but in which as possible Te is possible to improve the rigidity, the top outer end of the flange 10 By cutting (see 31a in FIG. 6),
A work space for inserting the electrode tips A and B for spot welding can be secured, and welding work with the wheel apron 15 can be facilitated (see FIG. 13). Further, when the outer end of the upper surface of the flange 10 is cut, a notch recess (see reference numeral 31c in FIG. 7) may be provided so as to be inclined only at a portion corresponding to the spot welding position.

Although only the example in which the frame of the present invention is applied to the front side frame has been described above, it is needless to say that the same can be applied to the rear side frame and other members whose rigidity needs to be changed in the longitudinal direction.

[0022]

Since the present invention is constructed as described above, it has the following effects. In a frame with a polygonal cross-section formed by bonding panels together, the number of bends in the cross-section can be increased or decreased by changing the position of the flange formed at the joint or by changing the cross-section. Along the way, the stiffness can be varied. In addition, when applying a frame whose rigidity is changed along the longitudinal direction to the side frame, the rigidity of the shock absorbing part is made higher than the rigidity of other shock resistant parts,
By securing the rigidity of the impact resistant part by other members joined to the impact resistant part, it is possible to reduce the weight of the side frame itself and to reliably absorb the impact due to buckling deformation in a predetermined deformation pattern. be able to. Said shock
From the center of the joint flange in the impact area to the frame width direction
By displacing outward, the rigidity of the impact resistant part is improved.
Can be made.

[Brief description of drawings]

FIG. 1 is a perspective view of a frame according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an exploded perspective view of a frame according to the present invention.

FIG. 5 is a sectional view of a different embodiment of the present invention.

FIG. 6 is a cross-sectional view of yet another embodiment of the present invention.

FIG. 7 is a cross-sectional view of yet another embodiment of the present invention.

FIG. 8 is a perspective view of still another embodiment of the present invention.

FIG. 9 is a schematic perspective view of a vehicle body front structure to which the present invention is applied.

FIG. 10 is a perspective view of a front side frame to which the present invention has been applied.

FIG. 11 is a perspective view of an engine mount mounting portion.

FIG. 12 is a perspective view of a suspension cross member attachment portion.

FIG. 13 is a cross-sectional view at the time of welding work of a wheel apron joint.

[Explanation of symbols]

1 frame, 2 inner panel, 3 outer panel 10 front side frame, 11 vehicle body, 12 dash panel 13 engine room, 14 front cross member 15 wheel apron, 16 suspension cross member 17 suspension tower, 18 engine member 19 engine mount bracket, A, B electrode tip

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 1-215624 (JP, A) JP-A 5-139242 (JP, A) Actually open 2-24777 (JP, U) Actually open 51- 34113 (JP, U) Actual development 2-115771 (JP, U) Actual development 2-16368 (JP, U) Actual development 2-106979 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B62D 25/20 B62D 21/00 B62D 21/15

Claims (5)

(57) [Claims] 1. A vehicle body structure for an automobile, comprising two panels, an outer panel and an inner panel, which are joined together to form a polygonal cross section and which comprises a front side frame having a shock absorbing portion and a shock resistant portion in the vehicle longitudinal direction. According to another aspect of the present invention, there is provided a vehicle body structure, wherein the joint flange at the impact absorbing portion is located substantially in the center in the frame width direction, and the joint flange at the impact resistant portion is displaced outward from the center in the frame width direction. 2. The vehicle body structure according to claim 1 , wherein the number of bent portions in the cross-sectional shape of the frame at the impact absorbing portion is larger than the number of bent portions at the impact resistant portion. Wherein the angular speed of the cross-sectional shape of the shock absorption site, the vehicle body structure for an automobile according to claim 1, characterized in that it has more than angular speed of the cross-sectional shape that put the impact site. 4. The impact resistance is provided at the front end of the front side frame.
Form the impact area and attach the joint flange on the lower surface of the impact resistant area.
Displace it to the outside of the car body and attach the front cross
The member according to claim 1, wherein the members are joined together.
Car body structure. 5. The impact resistance is provided at the rear end of the front side frame.
Form the impact area and attach the joint flange on the lower surface of the impact resistant area.
Displace it to the outside of the vehicle
The loss member according to claim 1, wherein the loss member is joined.
The body structure of the mounted car.