JP2826605B2 - Truck chassis frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a truck frame.

[0002]

2. Description of the Related Art An ordinary truck has a pair of left and right side rails extending in the front-rear direction of a vehicle body, each having a groove shape in cross section, and a plurality of rails arranged in a vehicle width direction and having both ends fixed to the side rails. The cross member includes a member having a groove-shaped cross section, a member having an I-shaped cross section, and V end portions fixed to the side rail. A so-called alligator-type member or the like formed by expanding in a letter shape is appropriately employed.

[0003] Both ends of the cross member in the vehicle width direction are:
Normally, the upper and lower flanges of the side rail web are fastened by rivets or bolts to the upper and lower flanges extending substantially in the horizontal direction from the upper and lower ends thereof, respectively. Conventionally, the flange width is formed to have substantially the same dimensions.

[0004] A carrier is mounted on the chassis frame via an intermediate member such as a vertical joist and a sub-frame, and the carrier is tightened to the side rail by fixing means such as U bolts.

[0005] Compared to the usual configuration in which both ends of the cross member of the chassis frame are fastened to the upper flange and the lower flange of the side rail, the both ends of the cross member are connected to the web of the side rail. It has been confirmed that the strength of the flange is greatly improved, for example, the fatigue limit is increased by about 40% and the durability life is more than doubled.

Accordingly, in the chassis frame in which the cross member is joined to the side rail web, there is room for reducing the weight by reducing the width of the side rail flange, which has sufficient strength, but according to the conventional technical common sense. When the flange widths of the upper flange and the lower flange are made equal, there is a problem that the allowable reduction of the flange width from the viewpoint of strength is relatively small, and a sufficient weight reduction effect cannot be achieved.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and utilizes the above-mentioned advantages of a chassis frame in which both ends in the vehicle width direction of a cross member are connected to webs of side rails. It is an object of the present invention to provide an underframe for a truck capable of effectively achieving weight reduction without impairing vertical bending rigidity and strength.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a pair of left and right side rails having a groove shape in cross section and extending in the front-rear direction of a vehicle body, and both ends arranged in a vehicle width direction. A chassis frame composed of a plurality of cross members fastened to the web of the side rail by rivets or bolts, and a cargo platform mounted on the chassis frame and fastened to the side rail by fixing means such as U bolts. In this structure, the flange width bu of the upper flange, which is disposed to extend substantially in parallel in the horizontal direction from the upper and lower ends of the web of the side rail, is smaller than the flange width bl of the lower flange. The present invention proposes a truck chassis frame characterized by the following.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. In the first embodiment of the present invention shown in FIGS. 1 to 3, a chassis frame 10 of a truck includes a pair of left and right side rails 12 extending in the vehicle longitudinal direction and having a groove-shaped cross section, and a vehicle width. The flanges 14f of the V-shaped enlarged portions 14 formed at both ends in the direction are formed by a number of rivets 16 or bolts having the same effect.
Alligator-type cross member 18 fastened to w.

The cross member 18 has an upper member 18u having a hat-shaped cross section, and a lower portion which is fixed to both ends in the vehicle width direction of the upper member 18u by rivets 20 to form the V-shaped enlarged portion 14. And a member 18l.

The side rails 12 are provided on the web 1
The upper flange 12fu and the lower flange 12fl are disposed so as to extend substantially in parallel in the horizontal direction from both upper and lower edges of the 2w.
The flange width bu of the upper flange 12fu is smaller than the flange width bl of the lower flange 12fl.

As shown in the conceptual side view of FIG. 3, a loading platform 24 is mounted on the chassis frame 10 via a vertical joist or a sub-frame 22, and the side rails 12 are fixed by fixing means 26 such as U bolts. It is tightly fastened.
In a state where the loading platform 24 is mounted, a lower flange 12f than the upper flange 12fu of the side rail 12 during traveling is provided.
A large load acts on l.

In the chassis frame 10 having the above-described structure, both ends of the cross member 18 in the vehicle width direction are connected to the web 12w of the side rail 12 by rivets 16 or bolts having the same effect.
The strength of the upper flange 12fu and the lower flange 12fl of the side rail 12 is greatly improved, and as described above, for example, the fatigue limit is increased by about 40%, and the durable life is more than doubled. , Reduce the flange width of the upper and lower flanges 12fu and 12fl, respectively.
The weight of the side rail 10 can be reduced.

In this case, a large load acts on the lower flange 12fl than the upper flange 12fu of the side rail 10 due to the influence of the loading platform 24 mounted on the chassis frame 10, so that the upper and lower flanges If the flange widths of 12fu and 12fl are reduced by the same amount, the reduction in the vertical bending rigidity of the chassis frame 10 is increased due to the large reduction in the flange width of the lower flange 12fl with a large load. However, as described above, the flange width bu of the upper flange 12fu is made smaller than the flange width bl of the lower flange 12fl, in other words,
The weight of the side rails 12 is reduced while preventing a decrease in the vertical bending rigidity of the chassis frame 10 by increasing the flange width reduction amount of the upper flange 12fu with a small load, and the weight of the chassis frame 10 is reduced rationally. Can be achieved.

The flange width b of the upper flange 12fu
It is preferable that the relative size of u and the flange width bl of the lower flange 12fl be in the range of 0.5 ≦ bu / bl ≦ 0.98. As described above, the reason why the lower limit of bu / bl is set to 0.5 is that the effect of the reduction of the flange width bu of the upper flange 12fu on the decrease in the vertical bending rigidity of the chassis frame 10 is relatively small. On the other hand, if the flange width bu is too small, it becomes difficult or unstable to mount the vertical joist or the subframe 22 mounted thereon, while the upper limit of bu / bl is set to 0.9.
8 is compared with the normal structure of bu / bl = 1.
This is because a sufficient weight reduction effect of the side rail 12 cannot be obtained.

Next, in the second embodiment of the present invention shown in FIG. 4 and FIG.
w and an upper flange 18u and a lower flange 18l extending laterally from the upper and lower edges of the web 18w, that is, forward or rearward of the vehicle body, are used. Both ends in the vehicle width direction are bent up and down, and each rivet 1
6 or the bolt of the same effect is fastened to the web 12w of the side rail 12.

The upper flange 12 of the side rail 12
The flange width bu of fu is formed smaller than the flange width bl of the lower flange 12fl, and the flange widths bu and b
The dimension of 1 is appropriately selected within the range of 0.5 ≦ bu / bl ≦ 0.98. Also in the second embodiment, similarly to the first embodiment, it is possible to effectively reduce the weight while securing the vertical bending rigidity and strength of the chassis frame 10.

The third embodiment of the present invention shown in FIGS.
In the embodiment, the web 1 is used as the cross member 18.
8w, an upper flange 18u and a lower flange 18 extending forward and backward from the upper and lower edges of the web 18w.
The upper and lower flanges 18u and 18l are bent at both ends in the vehicle width direction in the vehicle width direction, and the upper and lower flanges 18u and 18l are bent in the vertical direction. It is fastened to the web 12w.

The upper flange 12 of the side rail 12
The flange width bu of fu is formed smaller than the flange width bl of the lower flange 12fl, and the flange widths bu and b
The dimension of 1 is appropriately selected within the range of 0.5 ≦ bu / bl ≦ 0.98. Also in the third embodiment, as in the first embodiment, it is possible to effectively reduce the weight while securing the vertical bending rigidity and strength of the chassis frame 10.

In the first to third embodiments, both ends of the cross member 18 having various shapes in the vehicle width direction are directly fastened to the webs 12w of the side rails 12. 12w, a gusset having a groove-shaped cross-section or an L-shaped cross-section 2
The gussets are fastened by rivets or bolts, and both ends of the cross member can be fastened to the laterally extending flanges of the gussets by rivets or bolts. The lower flange 12fl from the flange width bu of 12fu
By forming the flange width bl large, and selecting the dimensions of the flange widths bu and bl in the range of 0.5 ≦ bu / bl ≦ 0.98, the same weight reduction effect as in each of the above embodiments can be obtained. Can play.

[0021]

As described above, the underframe of a truck according to the present invention is provided with a pair of left and right side rails having a groove shape in cross section and extending in the front-rear direction of the vehicle body, and arranged in the vehicle width direction. A chassis frame composed of a plurality of cross members fastened by rivets or bolts to the webs of the side rails at both ends, and a cargo bed mounted on the chassis frame and fastened to the side rail by fixing means such as U bolts. The upper flange has a flange width bu of an upper flange which extends substantially in parallel in a lateral direction from upper and lower ends of the web of the side rail, and is formed smaller than a flange width bl of a lower flange. There is an advantage that weight reduction can be achieved without impairing the vertical bending rigidity and strength of the chassis frame.

[Brief description of the drawings]

FIG. 1 is a partial plan view of a chassis frame according to a first embodiment of the present invention.

FIG. 2 is a front view of the chassis frame shown in FIG. 1;

FIG. 3 is a conceptual side view showing a state where a carrier is mounted on the chassis frame shown in FIG. 1;

FIG. 4 is a partial plan view of a chassis frame according to a second embodiment of the present invention.

FIG. 5 is a front view of the chassis frame shown in FIG. 4;

FIG. 6 is a partial plan view of a chassis frame according to a third embodiment of the present invention.

FIG. 7 is a front view of the chassis frame shown in FIG. 6;

[Explanation of symbols]

 10 chassis frame 12 side rail 18 cross member

Claims (1)

(57) [Claims] 1. A pair of left and right side rails having a groove shape in cross section and extending in the front-rear direction of a vehicle body, and a plurality of side rails arranged in a vehicle width direction and having both ends fastened to the side rail webs by rivets or bolts. A cross frame, and a loading frame mounted on the chassis frame and fastened to the side rails by fixing means such as U-bolts. A flange width bu of an upper flange, which is arranged to extend substantially in parallel in the lateral direction, is smaller than a flange width bl of a lower flange.