JPS63227477A - Front body structure for automobile - Google Patents

Abstract

PURPOSE:To improve rigidity and impact absorbency, by a method wherein a lower arm frame is fastened with a bolt in a state that the frame is positioned astride a space between a dash cross member, extending in the direction of the width of a car, and a front side frame to which the rear end part of the dash cross member is joined. CONSTITUTION:A dash cross member 4 extending in the direction of the width of a car is joined with a dash panel 3 by which a car room 1 of an automobile is partitioned from an engine room 2, and the rear end parts of a pair of front side frames 5 extending longitudinally across the interior of the engine room 2 are connected to the member 4. In this case, a lower arm set frame 14, to which a suspension lower arm 13 is rotatably mounted, is fastened to a bolt 16 in a state that it is positioned astride a space between the cross member 4 and the side frame 5. In this case, a bolt hole 17 formed in the fastening part, fastened against the side frame 5, of fastening parts against the cross member 4 and the side frame 5 is formed in the slotted shape in the longitudinal direction which forms the longitudinal direction of a car body.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a front body structure for an automobile that has high body rigidity and is excellent in absorbing shocks and the like that occur during a vehicle collision. .

[Conventional technology]

The front body structure of a conventional automobile is, for example,
As disclosed in Japanese Patent No. 20603, a lower arm set frame including a suspension lower arm is attached only to the front side frame.

[Problem that the invention seeks to solve]

In the conventional structure described above, in order to increase the vehicle body rigidity near the lower arm set frame, it is necessary to increase the rigidity of the front side frame. However, if the rigidity of the front side frame is increased, the front side frame becomes less likely to collapse, and its ability to absorb shocks generated during a vehicle collision deteriorates. Therefore, there has been a problem in that it is difficult to satisfy both vehicle body rigidity and shock absorbability.

Furthermore, as shown in FIG. 5, by fastening the lower arm set frame 21 across the dash cross member 22 and front side frame 23 with bolts 24, the vehicle body rigidity in the vicinity of the lower arm set frame 21 is increased. At the same time, the bolt holes 25 are formed in the shape of elongated holes whose longitudinal direction is the longitudinal direction of the vehicle body, so that the dash cross member 22 and the front side frame 23 are prevented from being crushed due to the fastening portions being displaced in the event of a vehicle collision. However, it is also possible to make it capable of absorbing shock.

However, since the fastening force of the ports 24 rapidly decreases when misalignment begins, a large impact absorption effect cannot be expected if the force is increased only due to the misalignment of the fastening portions. Therefore, it is still difficult to satisfy both vehicle body rigidity and shock absorbability.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the front body structure of an automobile according to the present invention is provided in the vehicle width direction along the dash panel that partitions the passenger compartment and the engine room. A lower arm to which a suspension lower arm is rotatably attached in a front body structure of an automobile comprising a dash cross member and a front side frame whose rear end is connected to the dash cross member and extends vertically through an engine room. A set frame is fastened to the dash cross member and the front side frame with bolts, and a fastening part where the lower arm set frame is fastened to the dash cross member, and a fastening part where the lower arm set frame is fastened to the front side frame. The bolt hole in one of the fastening parts is formed in the shape of a long hole whose longitudinal direction is in the longitudinal direction of the vehicle body.

[For production]

With the above configuration, external forces applied from the road surface to the lower arm set frame via the suspension lower arm during normal driving can be easily received by the reinforcing members of both the dash cross member and the front side frame in a distributed manner. The rigidity of the vehicle body near the lower arm set frame can be increased.

Additionally, when the lower arm set frame is subjected to an impact caused by a vehicle collision, the member of the dash cross member and front side frame to which the lower arm center frame is fastened through the round bolt hole will As the lower arm set frame retreats, it collapses and absorbs the impact while maintaining its fastened state.

On the other hand, even when the lower arm set frame is subjected to shocks generated during a vehicle collision, the member to which the lower arm set frame is fastened through the long bolt holes will
The elongated hole prevents the lower arm center frame from shifting and receiving a direct impact, so even if the strength of this member is set somewhat higher to increase the rigidity of the vehicle body, it will not affect the impact absorption effect.

Therefore, the strength and rigidity of the dash cross member and front side frame are set so that when the lower arm set frame is fastened and acts as an integral reinforcing member, the area around the lower arm set frame has sufficient body rigidity. By setting the member to which the lower arm set frame is fastened through the bolt hole of the hole to such a strength that it is easily crushed by the impact generated during a vehicle collision, it is possible to easily improve both vehicle body rigidity and shock absorption. can be satisfied.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

As shown in FIG. 1, a dash cross member 4 extending in the vehicle width direction is joined to a dash panel 3 that partitions a vehicle interior 1 and an engine compartment 2 of an automobile. The dash cross member 4 is connected to the rear end portions of a pair of left and right front side frames 5, which extend vertically through the engine room 2.

A pair of left and right apron frames 6, 6 are provided above the front side frames 5, 5, which extend vertically through the upper part of the engine room 2. Further, between the front side frames 5, 5 and the apron frame row 6, there are wheel aprons formed with wheel houses 7a, 7a that form the side walls of the engine compartment 2 and bulge into the interior of the engine compartment 2, respectively. 7.7 is provided.

Shroud panels 8, 8 are joined to the front ends of the wheel aprons 7, 7, respectively, and these shroud panels 8, 8 are connected to each other by a shroud upper 9 and a shroud lower 10.

On the upper surface of the bottom wall near the connecting portion of the dash cross member 4 and front side frame 5, there is a
) to (C) and as shown in FIG.
The nut set plates 12, which are loosely fitted, are welded.

On the other hand, a lower arm section frame 14 to which the suspension lower arm 13 is rotatably attached is fastened to the dash cross member 4 and the front side frame 5 with bolts 15 . Here, the lower arm center frame 14 is attached to the dash cross member 4.
The bolt holes 16 provided in the fastening portion fastened to the front side frame 5 are formed in a round hole shape, while the bolt holes 17 provided in the fastening portion fastened to the front side frame 5 are formed in a round hole shape.
is formed in the shape of a long hole whose longitudinal direction is the longitudinal direction of the vehicle body.

Further, a bent portion 4a is formed in the dash cross member 4 near the connection portion with the front side frame 5, and a sloped portion 5a at the rear end of the front side frame 5 is formed.
is formed, and a recess 20 is formed by both of them,
It is relatively easy to deform when subjected to impacts such as those generated during a vehicle collision.

In the above configuration, the lower arm set frame 14 is attached to the dash cross member 4 and the front side frame 5 by bolts 15, so that the suspension lower arm 13 can be easily removed from the road surface during normal driving. Through this, the external force applied to the lower arm set frame 14 is reliably transmitted to both the dash cross member 4 and the front side frame 5, and is received in a distributed manner. Therefore, the vehicle body rigidity near the lower arm set frame can be easily increased.

Furthermore, when a shock generated during a vehicle collision is applied to the lower arm center frame 14, the dash cross member 4 to which the lower arm set frame 14 is fastened through the round bolt holes 16, as shown in FIG. As the lower arm set frame 14 retreats, the vicinity of the bent portion 4a deforms relatively easily and absorbs the impact.

However, the front side frame 5 to which the lower arm set frame 14 is fastened through the long bolt holes 17 receives only a small amount of direct impact due to the displacement of the lower arm center frame 14 through the long holes. Therefore,
Since the front side frames 5 do not directly affect the impact absorption effect, the strength can be set so that the vicinity of the lower arm set frame 14 has sufficient vehicle body rigidity.

〔Effect of the invention〕

As described above, the front body structure of an automobile according to the present invention has the following features:
An automobile comprising a dash cross member provided in the vehicle width direction along a dash panel that partitions a vehicle interior and an engine room, and a front side frame whose rear end is connected to the dash cross member and extends vertically through the engine room. In the front vehicle body structure, the lower arm set frame to which the suspension lower arm is rotatably attached is fastened with bolts across the dash cross member and the front side frame, and the lower arm set frame is attached to the dash cross member. The bolt hole in either the fastening part fastened to the member or the fastening part fastened to the front side frame is formed in the shape of an elongated hole whose longitudinal direction is the longitudinal direction of the vehicle body. be.

As a result, the external force applied from the road surface to the lower arm set frame via the suspension lower arm during normal driving is dispersed and received by the reinforcing members of both the dash cross member and the front side frame, making it easier to lower the lower arm set frame. - It is possible to increase the rigidity of the vehicle body near the Musset frame.

Additionally, when the lower arm center frame is subjected to an impact caused by a vehicle collision, the member of the dash cross member and front side frame to which the lower arm set frame is fastened through the round bolt hole will As the lower arm set frame retreats, it collapses and absorbs the impact while maintaining its fastened state.

On the other hand, even when the lower arm set frame is subjected to shocks generated during a vehicle collision, the member to which the lower arm set frame is fastened through the long bolt holes will
Since the lower arm center frame does not shift due to the elongated hole and receives a direct impact, even if the strength of this member is set somewhat higher to increase the rigidity of the vehicle body, the impact absorption effect will not be affected.

Therefore, the strength and rigidity of the dash cross member and front side frame are set so that when the lower arm set frame is fastened and acts as an integral reinforcing member, the area around the lower arm center frame has sufficient body rigidity. By setting the member to which the lower arm set frame is fastened through the bolt hole of the hole to such a strength that it is easily crushed by the impact generated during a vehicle collision, it is possible to easily improve both vehicle body rigidity and shock absorption. It has the effect of being able to satisfy people.

[Brief explanation of drawings]

Figures 1 to 4 show one embodiment of the present invention, in which Figure 1 is a perspective view showing the vehicle body structure at the front of the vehicle, and Figure 2 (a) shows the mounting structure of the lower arm center frame. The plan view shown in FIG. 2(b) is A-A in FIG. 2(a).
The arrow sectional view, FIG. 2(c) is B- in FIG. 2(b).
3 is an exploded perspective view showing the shape of the nut set plate, etc., FIG. 4 is an explanatory sectional view showing the state of shock absorption at the time of a vehicle collision, and FIG. 5 is a diagram showing the process of developing the present invention. FIG. 3 is a plan view showing the devised mounting structure for the lower arm set frame. 1 is the passenger compartment, 2 is the engine room, 3 is the dash panel,
4 is a dash cross member, 5 is a front side frame, 13 is a suspension lower arm, 14 is a lower arm set frame, 15 is a bolt, 16 is a round bolt hole, and 17 is an elongated bolt hole. Figure 3: $4v! J

Claims (1)

[Claims] 1. A dash cross member installed in the vehicle width direction along the dash panel that partitions the vehicle interior and the engine room;
In the front body structure of an automobile, which includes a front side frame whose rear end is connected to the dash cross member and extends vertically through the engine compartment, the lower arm set frame to which the suspension lower arm is rotatably attached is attached to the dash cross member. It is fastened with bolts across the cross member and front side frame, and
The bolt hole in either the fastening part where the lower arm set frame is fastened to the dash cross member or the fastening part where it is fastened to the front side frame is a long hole whose longitudinal direction is the longitudinal direction of the vehicle body. A front body structure of an automobile characterized by being formed into a shape.