JPH0375386B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in longitudinal strength members such as automobile frames or side members.

The side members of an automobile frame or monocoque body are resistant to external forces from the vehicle longitudinal direction or diagonal longitudinal direction that cause the members to buckle.
It has a structure that deforms and absorbs energy while resisting.

The most efficient structure for absorbing the energy of external forces is generally a structure in which the front-rear strength members of the frame or side members undergo wall buckling that sequentially deforms them into a bellows shape from the front to the rear. There is.

However, in order to stably perform the wall buckling, it is desirable to match the axial direction of the applied load with the axial direction of the longitudinal strength member. However, in relation to other structural requirements of the vehicle, In many cases, it is not always possible to match.

In this case, the longitudinal strength members must be offset vertically and horizontally in accordance with the layout of the vehicle configuration. Energy absorption of such longitudinal strength members mainly results in bending deformation.

For this reason, conventionally, in order to increase the energy absorption due to bending deformation of the longitudinal strength member, in order to increase the bending rigidity at the offset portion, the plate thickness of the member is increased, reinforcement, gusset plate, etc. Some vehicles have taken this approach by providing a longitudinal strength member in the longitudinal direction strength member, but such a measure inevitably increases the weight of the vehicle and has the problem of worsening the fuel efficiency of the vehicle.

The present invention has been made in view of the above-mentioned problems of the conventional art, and effectively applies external forces by sequentially causing wall buckling in the front and rear directions in response to external forces not only from the front but also from diagonal directions. An object of the present invention is to provide a longitudinal strength member for an automobile that absorbs the energy of the vehicle.

In this invention, each of the left and right side frames is provided with an approximately Y direction in the vehicle width direction within an approximately horizontal plane toward the tip.
A cross member is attached to the tip of the branch member to connect the branch member in the vehicle width direction, and the branch member is connected to the vehicle at a position between the Y-shaped branch point and the tip. The above object is achieved by providing at least one connecting member connected in the width direction.

Further, the present invention achieves the above object by making the coupling member in the longitudinal direction strength member of the automobile a vertical plate-like member provided with a flange coupled to the opposing inner and lower surfaces of the branching member. It is something.

Further, the present invention provides that the coupling member in the longitudinal direction strength member of the automobile is formed by a connecting portion of a flat member that is attached across both the branch members and constitutes a part of these branch members, and the above-mentioned object is achieved. The goal is to achieve the following.

Further, in the above-mentioned strength member for an automobile, the present invention is characterized in that the flat connecting member is formed with a plurality of connecting portions and holes alternately in the front-rear direction at locations between the branching members. This aims to achieve the above objectives.

Further, in the strength member of the automobile, the present invention provides: between the Y-shaped branch point and the cross member;
The above objective is achieved by setting an arbitrarily set distance in advance to a set deformation length that efficiently absorbs energy when the member receives an external force in the front, back, or diagonal direction that causes it to buckle. .

Further, in the longitudinal direction strength member of an automobile, the left and right longitudinal direction strength members in the vehicle width direction are coupled to the second cross member at a position closer to the central part in the vehicle longitudinal direction than the Y-shaped branch part. In addition, the above object is achieved by interposing a reinforcement at the inner front corner of the joint portion.

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

FIG. 1 is a perspective view showing a first embodiment of the present invention, in which the front-rear strength member is a side frame 1 in the front-rear direction of an automobile. Only the right front part of frame 1 is shown). As shown in the figure, this side frame 1 includes a main frame 2 and a sub-frame 3 which branch out in a substantially Y-shape in the vehicle width direction in a substantially horizontal plane toward the distal end. A front cross member 4 is attached to the tip of the front cross member 4 to connect the main frame 2 and the sub frame 3 in the vehicle width direction. 3 in the vehicle width direction.

Further, the side frame 1 is integrally connected to the upper surface of a suspension cross member 7 extending in the vehicle width direction at a position rearward of the branch point 5 in a state perpendicular to the suspension cross member 7. A reinforcement 8 is integrally attached to the inner front corner of the joint between the suspension cross member 7 and the side frame 1 so as to connect the two. Reference numeral 9 in the figure indicates a front suspension mount.

The side frame 1, main frame 2, and subframe 3 each have a rectangular cross section and a closed cross section inside. Further, the main frame 2 is substantially aligned with the side frame 1 and arranged in the front-rear direction of the vehicle, and the sub-frame 3 is arranged at an angle of 21 to 22 degrees toward the front and outside of the vehicle with respect to the main frame 2. It is located with.

This angle is 30 degrees with respect to the longitudinal centerline of the vehicle.
This is based on theoretical calculations and experimentally determined values of the angle at which wall buckling can occur most efficiently and energy can be absorbed in response to an external force diagonally from the front forming an angle of 1.5 degrees. However, the angle can be changed to some extent depending on the joining position of the suspension cross member 7 and the main frame 2, whether or not the reinforcement 8 is attached, and its strength.

The main frame 2 and subframe 3
are smoothed so that their cross-sectional areas become smaller toward the tips, and this is to reduce the influence of the vertical offset of the main frame 2 and sub-frame 3. Reference numeral 10 in the figure indicates a weak force portion formed by a bead or corrugation formed on the lower surface of the main frame 2 and subframe 3, and the size of this bead or corrugation is
By increasing the distance closer to the front end of the main frame 2 and the subframe 3, or by making the distance between them smaller toward the front end, wall buckling is more likely to occur toward the front end of the main frame 2 and subframe 3. be.

The side frame 1 shown in FIG. 1 is assembled as shown in FIG. 2. FIG. 2 is an exploded perspective view of the main parts of the side frame 1.

As shown in FIG. 2, the main frame 2 connects the upper surface of the member 1A, which is integrally connected to the side frame 1 and has a substantially hat-shaped cross section, to the main frame plate 2.
A and a frame plate 1B, and the subframe 3 is attached to a member 3A having a substantially hat-shaped cross section, which is attached to the outer surface of the member 1A so as to project diagonally forward. It is formed by covering its upper surface with the plate 3B and the frame plate 1B.

That is, the frame plate 1B is approximately Y-shaped so as to cover the vicinity of the branching point 5 of the main frame 2 and sub-frame 3, and
B is attached to the front end of the frame plate 1B so as to continuously cover the main frame 2 and the sub-frame 3.

As shown in an enlarged view in FIG. 3, the coupling member 6 is a vertical plate-like member having flanges 6A and 6B coupled to opposing inner and lower surfaces of the main frame 2 and subframe 3. When an external force is applied from the front of the main frame 2 and the sub-frame 3 and they try to open, the main frame 2 and the sub-frame 3 are resisted by a lateral tensile force and maintain the Y-shape of the main frame 2 and the sub-frame 3. It is something.

Further, the shape of the connecting member 6 is characterized by being in the shape of a vertical plate as described above so as to have the above-mentioned function and not interfere with the wall buckling of the main frame 2 and the sub-frame 3 to absorb energy. shall be.

Further, as shown in an exploded state in FIG. 4, the reinforcement 8 covers the front, rear and upper surfaces of the suspension cross member 7, and is in contact with the inner surface of the side frame 1, so that it is integrally attached to these. is welded to. In addition, this reinforcement 8 has a triangular portion constituting a so-called diagonal member at the inner corner of the side frame 1 and the suspension cross member 7 in a plan view, as shown by a dashed line 8A in FIG. This prevents the side frame 1 from being deformed so as to tilt inward in the vehicle width direction.

In this embodiment, the main frame 2 and the sub-frame 3 are not bent by external forces applied not only in the longitudinal direction of the vehicle but also in the diagonal longitudinal direction, and the wall surface buckles sequentially from the tip. has the advantage of being able to absorb energy from external forces. Further, since the main frame 2 and the sub-frame 3 extend in a substantially Y-shape in the horizontal plane, they do not bend in the vertical direction.

In particular, the coupling member 6 prevents the main frame 2 and the subframe 3 from being expanded by external force, so that wall buckling is effectively achieved. Furthermore, since the connecting member 6 has a simple vertical plate shape, it has the advantage of being lightweight and low cost.

Furthermore, the reinforcement 8 effectively prevents the main frame 2 and subframe 3 from being bent inward in the vehicle width direction due to external force while maintaining the Y-shape.
The subframe 3 has the advantage that it can deform in the axial direction and efficiently absorb the energy of external force.

Furthermore, the connecting member 6 maintains the Y-shape of the main frame 2 and the sub-frame 3 against external forces from the vehicle longitudinal direction or diagonal longitudinal direction by its tensile resistance. This prevents the joints between the tip of the frame 3 and the front cross member 4, such as spot welds, from coming off, and thereby deforms the main frame 2 or subframe 3 in the axial direction, allowing the energy of external forces to be efficiently used. This makes it possible for it to be absorbed into the body.

Note that in the above embodiment, as shown in FIG.
The subframe 3 is configured to be attached to the side of the main frame 2, and this
As shown in the figure, the side frame 1 and the subframe 3 may be integrally bent and formed, and the main frame 2 may be attached to the inner surface thereof.

Furthermore, the connecting member 6 that connects the main frame 2 and the sub-frame 3 in the lateral direction is not limited to the mounting location, number, and configuration of the connecting member 6 shown in the embodiment shown in FIG. Any material that can maintain the Y-shape of the frame 2 and subframe 3 may be used.

Therefore, it may be configured as shown in FIG. 6, for example. That is, the coupling member 16 in this embodiment is connected to the main frame plate 2 that covers the upper surfaces of the main frame 2 and subframe 3.
A and the sub-frame plate 3B are constructed as an integral flat plate member. The coupling member 16
is the main frame 2 and subframe 3
A plurality of connecting portions 16A and holes 16B are provided alternately in the front-rear direction at a position above the space 11 between them.

In this embodiment, the connecting member 16 always resists the external force that tries to expand the main frame 2 and the sub-frame 3 by a tensile force, and also works together with the main frame 2 and the sub-frame 3 in the front-rear direction. It is successively buckled and deformed, thereby absorbing the energy of external force more efficiently and sufficiently.

In the embodiment shown in FIG. 6, the connecting portions 16A of the connecting member 16 are arranged toward the rear at equal intervals from the vicinity of the front cross member 4, but the arrangement of the connecting portions 16A and the hole portions 16B is different from that shown in the figure. The present invention is not limited to the above embodiments. Therefore, for example, the width of the connecting portion 16A in the longitudinal direction is made narrower as it approaches the front cross member 4, thereby causing wall buckling as it approaches the front cross member 4, similar to the weak force portion 10. You can make it easier. In this case, there is an advantage that wall surface buckling due to external force is performed smoothly.

Further, the connecting portion 16A may be formed between the Y-shaped frame plates 1B. Furthermore, the connecting portion 16A may be configured such that the distance between the front cross members 4 is the same as a preset deformation length between the Y-shaped branch point and the front cross member.

Further, the reinforcement 8 in each of the above embodiments is welded to the front and rear surfaces and the upper surface of the suspension cross member 7, as shown in FIG.
The reinforcement 8 is configured to be welded to the inner surface of the side frame 1, but the reinforcement 8 may include a triangular portion 8A to prevent the side frame 1 from being bent inward by external force. good.

Therefore, bolt holes 12 may be formed as shown in FIG. 7, and the suspension may be fixed to the side frame 1 and the suspension cross member 7 with bolts. Alternatively, as shown in FIG. 8, the structure may be divided into a triangular portion 8A and a rectangular portion 8B on which the suspension cross member 7 is seated.

Although the above embodiments are directed to the front side of the side frame of an automobile, the present invention is also applicable to the rear side. Further, the present invention is generally applied to longitudinal strength members of automobiles, and therefore also to side members of monocoque bodies having no frame.

Further, the front cross member 4 may also serve as a bumper or bumper reinforcement.

Since the present invention is configured as described above, it has the advantage of being able to cause wall surface buckling to effectively absorb the energy of external forces applied not only in the longitudinal direction of the automobile but also in the diagonal longitudinal direction. It has a good effect. In addition, since the Y-shape can be maintained against external forces as described above, these external forces can be applied to the longitudinal strength member in the axial direction, thereby ensuring energy absorption. has.

In addition, since the entire Y-shaped longitudinal strength member is prevented from being bent inward in the vehicle width direction in response to the external force described above, the external force is applied in the axial direction of the longitudinal strength member, increasing efficiency. It has the excellent effect of being able to absorb energy in a controlled manner.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the longitudinal strength member for an automobile according to the present invention, Fig. 2 is an exploded perspective view of main parts of the embodiment, and Fig. 3 is an enlarged view of a connecting member in the embodiment. FIG. 4 is an exploded perspective view showing the vicinity of reinforcement in the same embodiment, FIG. 5 is an exploded perspective view similar to FIG. 2 showing the second embodiment of the present invention, and FIG. A perspective view showing a third embodiment of the present invention, and FIGS. 7 and 8 are a perspective view and an exploded perspective view showing other embodiments of reinforcement. DESCRIPTION OF SYMBOLS 1... Side frame, 2... Main frame, 3... Sub frame, 4... Front cross member, 5... Branch point, 6... Connection member, 6A...
...Flange, 6B...Flange, 7...Suspension cross member, 8...Reinforcement, 16...Connection member, 16A...Connection part, 16
B... Hole.

Claims (1)

[Scope of Claims] 1. Each of the left and right side frames is provided with a branching member extending in a substantially Y-shape in the vehicle width direction in a substantially horizontal plane toward the distal end, and the branching members are connected in the vehicle width direction. A cross member is attached to the tip end of the Y-shape, and at least one connecting member connects the branch member in the vehicle width direction at a position between the Y-shaped branch point and the tip end. Strength member. 2. The longitudinal strength member for an automobile according to claim 1, wherein the coupling member is a vertical plate-like member having flanges coupled to opposing inner and lower surfaces of the branching member. . 3. The connecting member as set forth in claim 1, wherein the connecting member is attached across both the branching members and is formed by a connecting portion of a flat plate member that constitutes a part of these branching members. A structural member that strengthens automobiles in the longitudinal direction. 4. The vehicle front-rear direction according to claim 3, wherein the flat coupling member has a plurality of connecting portions and holes alternately formed in the front-rear direction at locations between the branch members. Strength member. 5 Between the Y-shaped branch point and the cross member,
Claim 1, characterized in that the distance arbitrarily set in advance is a set deformation length for efficiently absorbing energy when the member is subjected to an external force in a longitudinal or diagonal direction that causes it to buckle. The longitudinal strength member of an automobile according to any one of items 1 to 4 above. 6. At a position closer to the central part in the longitudinal direction of the vehicle than the Y-shaped branch, the left and right longitudinal strength members in the vehicle width direction are coupled to the second cross member, and at the inner front corner of the coupling part, a lean A longitudinal strength member for an automobile according to any one of claims 1 to 5, characterized in that a hosement is interposed therebetween.