JPH10297540A - Automobile chassis frame and body construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To check crushing deformation of a floor frame by setting up a reinforcing plate aslant in the gradient lower part toward a lower end from the upper end so as to halve an air space partitioned off by a bottom wall and both side walls of the floor frame and a floor panel. SOLUTION: A reinforcing plate 16 extending over at least a part of a floor frame 9 in the longitudinal direction, is set up in an airspace partitioned off by a bottom wall 10 and both side walls 11 of this floor frame 9 and a floor panel 4. Then, the reinforcing plate 16 is set up aslant in the gradient lower part toward a lower end from the upper end so as to halve the airspace. When any compressive load acts on the floor frame 9 in the longitudinal direction, the floor frame 9 tries to make its cross sectional form into a parallelogrammatic crushing deformation, but the reinforcing plate 16 works so as to check this crushing deformation of the floor frame 9, so that any possibility that this floor frame 9 might be largely taken into permanent deformation is hindered from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floor frame extending substantially in the front-rear direction of a vehicle body, which is disposed below a floor panel constituting a floor surface of a passenger compartment, wherein the floor frame comprises a bottom wall and the bottom wall. A pair of side walls rising upward from each side edge in the vehicle body width direction, and a pair of flanges projecting horizontally from the upper edge of each side wall, and these flanges are provided on the lower surface of the floor panel. The present invention relates to a vehicle body structure that is fixed.

[0002]

2. Description of the Related Art A vehicle body structure of the above-mentioned type employed in a cab-over type truck, bus, passenger car or other type of automobile is well known (for example, Japanese Patent Application Laid-Open No. Sho 56-108).
357). According to this type of vehicle structure, the floor frame is disposed below the floor panel, so that the strength of the vehicle body can be increased, and even when a large external force acts on the vehicle body in the front-rear direction, the vehicle body Can reduce the amount of permanent deformation.

At this time, in order to effectively increase the strength of the vehicle body by the floor frame, it is necessary to set the thickness of the floor frame to be large and sufficiently increase the strength of the floor frame. However, when the thickness of the floor frame is set to be large in this way, the weight of the entire vehicle body increases,
The disadvantage of rising costs is inevitable.

[0004] Therefore, it is conceivable to reinforce the floor frame by attaching a reinforcing member to the floor frame and reduce the thickness of the floor frame itself by increasing the overall strength. For example, a substantially U-shaped reinforcing member along the bottom wall and both side walls of the floor frame is fixed to the inner side surface of the floor frame, or a reinforcing member in a horizontal position in which each edge is fixed to both side walls of the floor frame is provided. It is. However, the present inventor's studies have revealed that simply attaching such a reinforcing member to the floor frame cannot increase the strength as desired and cannot expect a great effect. .

[0005]

SUMMARY OF THE INVENTION The present invention has been made based on the above-described novel recognition, and an object of the present invention is to increase the strength of a vehicle body and to make the thickness of a floor frame sufficiently small. It is an object of the present invention to provide a vehicle body structure that can be used.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a vehicle body structure of the type described at the beginning,
A reinforcing plate extending over at least a part of the entire length in the longitudinal direction of the floor frame is disposed in a space defined by the bottom wall and both side walls of the floor frame and the floor panel, and the reinforcing plate divides the space into two. The vehicle body structure of an automobile is characterized in that it is disposed obliquely downward from the upper end to the lower end so that at least the upper end of the upper end and the lower end is fixed to the floor frame. (Claim 1).

At this time, in the vehicle body structure according to the first aspect, when a compressive load acts on the floor frame in a longitudinal direction thereof, a compressive load is applied to the reinforcing plate in a width direction thereof. It is advantageous if the inclined position of the reinforcing plate is determined, and only the upper end of the upper end and the lower end of the reinforcing plate is fixed to the floor frame (claim 2).

In the vehicle body structure according to the first aspect, when a compressive load is applied to the floor frame in a longitudinal direction thereof, a tensile load is applied to the reinforcing plate in a width direction thereof. Advantageously, the inclined position of the reinforcing plate is determined, and both the upper end and the lower end of the reinforcing plate are fixed to the floor frame.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a side view showing a cab of a truck which is an example of an automobile having a vehicle body structure according to the present invention, and FIG. 2 shows an outer contour of the cab by a dashed line, and shows only a part of the elements. It is the top view shown by the solid line. The term “front” or “rear” used in the present specification means front and rear with respect to the forward direction F of the vehicle, and a direction orthogonal to the front and rear direction is the width direction W of the vehicle body. .

Referring to FIGS. 1 and 2, a truck body 1, ie, a cab, forms a roof panel 2 defining an upper part of a vehicle compartment, a quarter panel 3 constituting a side portion of the vehicle body 1, and a floor surface of the vehicle compartment. It has various panels, such as a floor panel 4, a back panel 5 that partitions the rear of the vehicle compartment, and a front panel 6 that is located at the front of the vehicle body. Reference numeral 7 denotes a front pillar, and reference numeral 8 denotes a windshield provided in a front part of a vehicle compartment. Further, in the illustrated vehicle body structure, floor frames 9, 9a extending substantially in the front-rear direction of the vehicle body 1 are arranged below the floor panel 4 as shown by solid lines in FIG. A pair of floor frames 9, substantially symmetric with respect to the center CL in the direction W,
9a is provided. These floor frames 9, 9
a has substantially the same structure, except that they are symmetric.

As shown in FIGS. 3 and 4, which are enlarged sectional views taken along lines III-III and IV-IV in FIG. 2, each floor frame 9, 9a has a bottom wall 10, 10a and a bottom wall 10, 10a. 10
a, a pair of side walls 11, 11a rising upward from respective side edges in the vehicle body width direction W, and a pair of flanges 12, 1 projecting outward in the horizontal direction from upper end edges of the respective side walls 11, 11a.
2a, bottom walls 10, 10a, both side walls 1
1, 1a and both flanges 12, 12a are integrally extended in the front-rear direction of the vehicle body 1. Each floor frame 9, 9a has a substantially U-shaped cross section. These flanges 12 and 12a are fixed to the lower surface of the floor panel 4 by spot welding, as indicated by crosses in FIGS.

The floor frames 9 and 9a constructed as described above are supported by the chassis frame 13 via intermediate members (not shown), whereby the body 1
Is mounted on the chassis frame 13. A carrier (not shown) is supported on a chassis frame portion behind the vehicle body 1. Further, each panel, the front pillar 7, and the floor frames 9, 9a of the vehicle body 1 described above are made of a high-strength material such as a steel plate.

As shown in FIGS. 3 and 4, a substantially U-shaped first reinforcing member 14, 14a disposed along the inner surface of the floor frame 9, 9a is fixed to the floor frame 9, 9a. Each edge of the second reinforcing members 15 and 15a in the posture is fixed to each side wall 11 and 11a of each floor frame 9 and 9a via the first reinforcing members 14 and 14a. These reinforcing members 14, 14b, 15, 15b are also made of a high-strength material such as a steel plate, and are provided over the entire length of each floor frame 9, 9a or a part thereof.

Here, for example, for a running truck,
If a large external force P acts from the front, the vehicle body 1
Is located behind the vehicle, the vehicle body 1 receives a large load from the front and rear. As a result, the vehicle body 1 tends to be compressed and deformed, but at this time, the permanent deformation of the vehicle body 1, that is, its plastic deformation, is suppressed by the reinforcing function of the floor frames 9 and 9 a.

As described above, the strength of the vehicle body 1 can be increased by the floor frames 9 and 9a. Conventionally, however, in order to surely increase the strength, the floor frame is made of a thick plate material. . For this reason, the weight of the vehicle body increased, and the disadvantage of increasing the cost was unavoidable.

As described above, the first and second reinforcing members 14, 14a, 15, 1 are provided on the floor frames 9, 9a of this embodiment.
5a are fixed, and the floor frames 9, 9
Although a is reinforced, the reinforcing members alone cannot sufficiently reinforce the floor frames 9 and 9a, and the thickness of the frames 9 and 9a cannot be sufficiently reduced.

The present inventor has analyzed the plastic deformation of the floor frame in order to clarify the cause, and as a result, has been able to clarify the following facts.

FIG. 9B shows that the truck receives a large external force P from the front and a compressive load acts on the floor frame 9 provided with the first and second reinforcing members 14 and 15 in the longitudinal direction thereof. FIG. 9A is an explanatory diagram showing a permanent deformation state of the floor frame 9 at the time, and FIG. 9A shows a state before the deformation. As can be seen from FIG. 9B, when a large compressive load acts on the floor frame 9, the floor frame 9
Is crushed so that the cross-sectional shape of the bottom wall 10 and the side walls 11 forms a parallelogram. As shown in FIG. 9A, the floor frame 9 having a substantially rectangular cross-sectional shape before deformation is permanently deformed as if the match box was crushed.
The other floor frame 9a collapses and deforms symmetrically with the floor frame 9 shown in FIG. 9B.

Here, the first and second reinforcing members 14 and 15 are fixed to the floor frame 9, and these members 14 and 15 prevent the floor frame 9 from being crushed and deformed into a parallelogram. It cannot perform its function of blocking effectively. Once the floor frame 9 is permanently deformed into the shape of a parallelogram, the cross-sectional shape changes and the cross-sectional strength is extremely reduced. For these reasons, the floor frame 9 cannot be effectively reinforced only by providing the first and second reinforcing members 14 and 15, and conventionally, the plate thickness is set to be extremely large, and this becomes There was no choice but to prevent it from being crushed and deformed.

Therefore, in the vehicle body structure of the present embodiment, attention is paid to the above-mentioned points, and as shown in FIGS. 3 and 4, the bottom walls 10, 10a and the side walls 11, 1 of the floor frames 9, 9a are provided.
1a and the space S defined by the floor frame 4
Inside, reinforcing plates 16, 16a extending over at least a part of the floor frames 9, 9a in the longitudinal direction are arranged. The reinforcing plates 16 and 16a are arranged obliquely downward from the upper ends 17 and 17a to the lower ends 18 and 18a so as to divide the space S into two. In the example shown, the reinforcing plates 16 and 16a are provided in the range indicated by Q in FIG.
The reinforcing plates 16, 16a can be extended over the entire length of 9a. As will be described later, at least the upper ends 17, 17a of the upper ends 17, 17a and the lower ends 18, 18a of the reinforcing plates 16, 16a are fixed to the floor frames 9, 9a.

In the example shown in FIG. 3 and FIG.
6, 16a are located on the side of the vehicle body 1 away from the center CL in the width direction, that is, on the outer side in the vehicle body width direction,
The lower ends 18, 18a occupy positions closer to the width center CL of the vehicle body 1, and the upper ends 17, 17a and the lower ends 18, 1
8a are the first reinforcing members 14, 14 by arc welding AC.
a, whereby the reinforcing plates 16, 16a are fixed to the floor frames 9, 9a.

As shown in FIG. 9B, when a compressive load is applied to the floor frame 9 in the longitudinal direction, the floor frame 9 is crushed into a parallelogram and tends to deform. However, at this time, since the reinforcing plate 16 arranged in an inclined position is provided inside the floor frame 9, the reinforcing plate 16 is attached to the floor frame 9.
Acts to prevent the crush deformation of the floor frame 9.
Prevents large permanent deformation. (A) of FIG.
(B) shows the floor frame 9 when the reinforcing plate 16 is provided.
It is an explanatory view showing a state before the deformation and after the permanent deformation. From this figure, it can be understood that the permanent deformation such that the floor frame 9 is crushed by the reinforcing plate 16 can be effectively suppressed. The reinforcing plate 16a shown in FIG. 4 works in exactly the same way, and prevents the crush deformation of the floor frame 9a.

As described above, when a compressive load acts on the floor frames 9, 9a in the longitudinal direction, the permanent deformation of the floor frames 9, 9a can be prevented or suppressed by the reinforcing plates 16, 16a. Each floor frame 9, 9a exhibits its original reinforcing effect. For this reason, even if the thickness of the floor frames 9 and 9a is set to be much smaller than in the past, the strength of the vehicle body 1 can be maintained, the weight of the vehicle body 1 can be reduced, and the cost can be reduced. Become. Also, the first and second reinforcing members 14, 14
Even if a, 15 and 15a are omitted, the squashing deformation of the floor frames 9 and 9a can be prevented by the reinforcing plates 16 and 16a. This is the same in an example described later.

As shown in FIG. 6, the inclined position of the reinforcing plate 6 can be reversed from that in FIG. The same applies to the reinforcing plate 16a provided on the other floor frame 8a.

Here, in the example shown in FIGS. 3 and 4, when an external force P is applied to the vehicle body 1 and a compressive load acts on the floor frames 9 and 9a in the longitudinal direction by this, FIG. As is apparent from the deformed state of the floor frame shown in b), a compressive load is applied to the reinforcing plates 16, 16a in the width direction of the reinforcing plates 16, 16a by the floor frames 9, 9a. Therefore, in this case, if the upper ends 17, 17a of the reinforcing plates 16, 16a are fixed to the floor frames 9, 9a, the lower ends 18, 17a of the reinforcing plates 16, 16a are fixed.
Even if 18a is not fixed to the floor frames 9, 9a, the reinforcing plates 16, 16a exhibit the above-mentioned reinforcing function. That is, when a compressive load is applied to the floor frames 9, 9a in the longitudinal direction, the reinforcing plates 16, 16a
In contrast, the inclined positions of the reinforcing plates 16 and 16a are determined so that a compressive load is applied in the width direction, and the reinforcing plates 16 and 16a are inclined.
a of the upper end portions 17 and 17a and the lower end portions 18 and 18a
Only the upper end can be configured to be fixed to the floor frames 9, 9a. Thereby, the reinforcing plates 16, 16a
It is not necessary to apply welding AC to the lower end portions 18 and 18a, and the floor frames 9 and 9a of the reinforcing plates 16 and 16a are eliminated.
Can be simplified, and the cost can be reduced.

On the other hand, when the reinforcing plate 16 is arranged as shown in FIG. 6, when a compressive load is applied to the floor frame 9 in the longitudinal direction, the state of the floor frame shown in FIG. As is apparent, a tensile load acts on the reinforcing plate 16. In this case, unless both the upper end 17 and the lower end 18 of the reinforcing plate 16 are fixed to the floor frame 9, the reinforcing plate 16 cannot function to reinforce the floor frame 9. That is, in this case, when the compressive load acts on the floor frame 9 in the longitudinal direction, the inclined position of the reinforcing plate 16 is determined so that the tensile load is applied to the reinforcing plate 16 in the width direction. The upper end 17 and the lower end 18 of the reinforcing plate 16 are both fixed to the floor frame 9. The same applies to the reinforcing plate 16a provided on the other floor frame 9a.

According to this configuration, the upper end 1 of the reinforcing plate 16
It is necessary to apply welding AC to 7 and the lower end 18,
When a compressive load is applied to the floor frame 9, the reinforcing plate 1
Since a tensile load acts on 6, there is obtained an advantage that it can be prevented from being bent and deformed even if its thickness is smaller than when a compressive load is applied thereto.

As described above, at least the upper ends 17, 17a of the upper ends 17, 17a and the lower ends 18, 18a of the reinforcing plates 16, 16a are fixed to the floor frames 9, 9a.

Reinforcement plate 1 for floor frames 9, 9a
The mode of assembling 6 and 16a is not limited to the example described above, and can be appropriately selected. For example, as shown in FIG. 7, the upper end portion 17 of the reinforcing plate 16 is brought into close contact with the side wall 11 of the floor frame 9 with a large area, the upper end portion 17 is sandwiched between the side wall 11 and the second reinforcing member 15, and these are marked with a cross. It can be fixed by spot welding, as shown by adding. In the example of FIG. 7, the lower end 18 of the reinforcing plate 16 is spot-welded to the bottom wall 10 of the floor frame 9, and an extension 19 is formed at the lower end 18. And the upper end thereof is sandwiched between the side wall 11 and the second reinforcing member 15, and these are fixed by spot welding. In this example, the first reinforcing member is not provided.

In the example shown in FIG. 8, the upper end 17 of the reinforcing plate 16 is configured in the same manner as in FIG. 7, but the lower end 18 is separated from the inner surface of the floor frame 9. When a compressive load acts on the floor frame 9 shown here,
Since the lower end portion 18 of the reinforcing plate 16 collides with the floor frame 9 and a compressive load acts on the reinforcing plate 16, the lower end portion 18 may be separated from the floor frame 9 in a normal state.

The present invention can be widely applied not only to trucks but also to the body structure of automobiles such as buses and passenger cars.

[0033]

According to the vehicle body structure according to the first aspect of the present invention, the squashed deformation of the floor frame can be effectively suppressed by the inclined reinforcing plate, thereby reducing the thickness of the floor frame as compared with the related art. It can be set significantly smaller.

According to the vehicle body structure of the second aspect, since the lower end of the reinforcing plate is not fixed to the floor frame,
The reinforcing plate can be easily assembled to the floor frame.

According to the vehicle body structure of the third aspect, when a compressive load acts on the floor frame in the longitudinal direction, a tensile load acts on the reinforcing plate, so that the thickness of the reinforcing plate is set small. However, the reinforcing plate surely reinforces the floor frame.

[Brief description of the drawings]

FIG. 1 is a side view showing a cab of a truck.

FIG. 2 is a schematic plan view in which the outline of the cab shown in FIG. 1 is indicated by a chain line, and only some of the elements are indicated by solid lines.

FIG. 3 is an enlarged sectional view taken along the line III-III of FIG. 2;

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is an explanatory cross-sectional view showing a state before and after permanent deformation of a floor frame when a reinforcing plate is provided.

FIG. 6 is a cross-sectional view similar to FIG. 3, showing an example in which the inclined position of the reinforcing plate is changed.

FIG. 7 is a sectional view similar to FIG. 3, showing another example of a reinforcing plate.

FIG. 8 is a sectional view similar to FIG. 3, showing still another example of a reinforcing plate.

FIG. 9 is an explanatory sectional view showing a state before and after a permanent deformation of the floor frame when there is no reinforcing plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 4 Floor panel 9 Floor frame 9a Floor frame 10 Bottom wall 10a Bottom wall 11 Side wall 11a Side wall 12 Flange 12a Flange 16 Reinforcement plate 16a Reinforcement plate 17 Upper end 17a Upper end 18 Lower end 18a Lower end W width direction

Claims (3)

[Claims] 1. A floor frame extending substantially in the front-rear direction of a vehicle body is disposed below a floor panel constituting a floor surface of a vehicle compartment. The floor frame includes a bottom wall and each of the bottom wall in the vehicle width direction. An automobile comprising a pair of side walls rising upward from side edges and a pair of flanges projecting horizontally from the upper edge of each side wall, and these flanges are fixed to the lower surface of the floor panel. In the vehicle body structure, a reinforcing plate extending over at least a part of the entire length in the longitudinal direction of the floor frame is disposed in a space defined by a bottom wall and both side walls of the floor frame and the floor panel, and the reinforcing plate is The space is divided obliquely downward from the upper end to the lower end so as to bisect the space, and at least the upper end of the upper end and the lower end is fixed to the floor frame. Body structure of a motor vehicle, characterized by being. 2. When the compressive load acts on the floor frame in its longitudinal direction, the inclined position of the reinforcing plate is determined so that a compressive load is applied to the reinforcing plate in the width direction, and 2. The vehicle body structure of an automobile according to claim 1, wherein only the upper end of the upper and lower ends of the reinforcing plate is fixed to the floor frame. 3. The inclined position of the reinforcing plate is determined so that when a compressive load acts on the floor frame in a longitudinal direction thereof, a tensile load is applied to the reinforcing plate in a width direction thereof, and The vehicle body structure according to claim 1, wherein both the upper end and the lower end of the reinforcing plate are fixed to a floor frame.