JPH077261Y2 - Truck undercarriage frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a chassis frame of a truck.

(Prior Art) Most conventional trucks include a pair of left and right side rails extending in the front-rear direction of the vehicle body, each of which has a groove-shaped cross section, and a vehicle-width direction in which the side rails are arranged at intervals in the front-rear direction of the vehicle body. And a plurality of cross members fixed to the side rail by rivets or bolts at both ends thereof.

The cross member has a groove-shaped cross section, an I-shaped cross section, and a so-called alligator type member in which both ends fixed to the side rails are formed with V-shaped joints. The both end portions of these cross members are fixed to the upper and lower flanges of the side rails or the web portion by the rivets or bolts, but in any case, they are connected to the side rails. The end of the cross member to be formed has a flat plate shape.

(Problems to be solved by the invention) When a truck travels on a rough road or rough terrain with many irregularities in a loaded state, a large vertical bending load acts on the chassis frame. When a vertical bending load is applied to the chassis frame and, for example, a concave bending deformation is caused upward, the side rails have a maximum elongation at the lower portion of the neutral shaft, particularly at the lowermost flange at the lower end, and Maximum shrinkage occurs in the upper part of the neutral shaft, especially in the uppermost upper flange. However, at the portion where the end of the cross member is fixed by the rivet or the bolt, the free deformation of the side rail is restrained and hindered by the cross member. There has been a problem that large stress is generated in each part of the rail, and cracks are likely to occur. For this reason, conventionally, measures such as mounting a reinforcing plate or an L-shaped reinforcing material in multiple layers as necessary are conventionally adopted in the cross-member connecting portion of the side rail, but this makes the structure complicated. At the same time, the number of parts increases, the manufacturing cost increases, and the weight increases.

An object of the present invention is to solve the above-mentioned problems of the conventional chassis frame, to provide a chassis frame of a truck which has a simple structure, a small number of parts, is inexpensive, and is excellent in durability and reliability. To do.

(Means for Solving the Problems) The undercarriage frame of a truck according to the present invention was conceived to achieve the above-mentioned object, and includes a pair of left and right side rails extending in the vehicle front-rear direction and a vehicle width direction. A cross member whose both end portions are fixed to the side rails by rivets or bolts, and which extend in the vehicle width direction on the plate portion between the rivets or bolts at the end portion of the cross member. It is characterized by forming a fold-like portion.

(Operation) According to the present invention, since the fold-shaped portion extending in the vehicle width direction is formed in the plate portion between the rivets or the bolts at the end portion of the cross member, a vertical bending load is applied to the chassis frame. When actuated, the cross member can easily expand and contract in the longitudinal direction of the vehicle body by following the expansion and contraction deformation of the side rail far from the neutral axis, in other words, the expansion and contraction deformation of each side rail part in the cross member joint. Is not restrained by the cross member, a large shearing force is not generated in the cross member fastening rivet or bolt, and the stress concentration in the plate portion of the side rail adjacent to the rivet or bolt is eliminated or effectively reduced. It

(Embodiment) An embodiment of the present invention will be specifically described below with reference to the accompanying drawings. First, in the first embodiment of the present invention shown in FIGS. 1 to 3, reference numeral 10 generally indicates a chassis frame of a truck, and the frame includes a pair of left and right extending in the longitudinal direction of the vehicle body. Side rails 12 each having a groove-shaped cross section,
It is arranged in the width direction of the vehicle, and both ends of the side rail are
12 includes a cross member 16 fixed by rivets or bolts 14.

The cross member 16 has a groove-shaped cross section, and its upper flange 16fu and lower flange 16fl are fixed to the corresponding upper flange 12fu and lower flange 12fl of the side rail 12 by the rivet or bolt 14. A pleated portion 18 having an appropriate shape such as a gutter shape or a groove shape extending in the vehicle width direction is formed in the plate portion between the rivets or bolts at the ends of the upper flange 16fu and the lower flange 16fl of the cross member 16. .

According to the above configuration, the underframe of the truck while the truck is traveling
When a vertical bending load is applied to 10 and a vertical bending moment as indicated by an arrow M in FIG. 2 is applied to the side rail 12, for example, the side rail 12 is
Lower flange 12 farthest away from the neutral axis NN
The maximum elongation deformation occurs in fl as indicated by the arrow a, and the upper flange furthest away from the neutral axis NN is the upper flange.
The maximum shrinkage deformation occurs in 12fu as indicated by arrow b. When the lower flange 12fl and the upper flange 12fu are expanded and contracted, rivets or bolts are attached to these flanges.
Since the plate portion between the rivets or the bolts of the corresponding lower flange 16fl and upper flange 16fu of the cross member 16 connected by 14 is provided with the fold-shaped portion 18 extending in the vehicle width direction, And upper flange 16
fl and 16fu are the lower and upper flanges of the side rail 12fl
It is possible to easily follow the expansion and contraction deformation of 12fu and 12fu. Therefore, the above side rail flanges 12fl and 12fu
There is little restraint against expansion and contraction of the flange, so that no large shearing force is generated in the rivet or bolt 14, and the flange 12fl
Since the stress concentration in the portions of the and 12fu adjacent to the rivet or the bolt is effectively reduced, the durability and reliability of the side rail 12 are improved. As a result, it is not necessary to reinforce the side rails 12 at the cross member coupling portion, or at least the amount of the reinforcing material used can be greatly reduced, which is advantageous in that the structure is simple and the cost is low. Weight reduction can be achieved.

Next, FIGS. 4 and 5 show a second embodiment of the present invention. In this embodiment, both end portions in the vehicle width direction of the upper flange 16fu and the lower flange 16fl of the cross member 16 having a groove-shaped cross section are extended outward and bent downward and upward, respectively, to attach portions 16fu 'and 16fl. ′, And these mounting portions 16fu ′ and 16fl ′ are fixed to the web 12w of the side rail 12 by rivets or bolts 14.
A fold-shaped portion 18 having an appropriate shape such as a trough shape or a groove shape is formed on the plate portion between the rivets or bolts of the mounting portions 16fu 'and 16fl'.

Also in this structure, when a vertical bending load is applied to the chassis frame 10, the side rail web 12w can be easily expanded and contracted at the cross member upper and lower flange mounting portions 16fu 'and 16fl' in the fold-shaped portion 18. The expansion and contraction of the mounting part of the rivet or bolt 14 away from the neutral axis of the rivet or bolt 14 is not strongly restrained, so that no large shearing force is generated in the rivet or bolt 14
A large concentration of stress does not occur in the portion of the web 12w adjacent to 14, and damage to the portion is effectively avoided, so that the same effect as the first embodiment can be obtained.

FIG. 6 shows a third embodiment of the present invention. In this embodiment, the members 16a and 16b each having a groove-shaped cross section are provided.
Web parts are brought into contact with each other back to back and are integrally connected by a large number of rivets or bolts 20 to form a cross member 16 having an I-shaped cross section. The cross member 16 has an upper flange 16fu and a lower flange 16fl. Both end portions in the vehicle width direction are fixed to the upper flange 12fu and the lower flange 12fl of the side rail 12 by rivets or bolts 14, respectively. Above upper flange 16fu and lower flange 16
At both ends in the vehicle width direction of fl, fold-like portions 18 having an appropriate shape such as a trough shape or a groove shape similar to those of the first embodiment are formed.

It is apparent that, also in this embodiment, the simplification of the structure, the reduction of the manufacturing cost, and the reduction of the weight can be achieved substantially similarly to the first embodiment. In addition, the upper and lower flanges 16fu and 16 of the cross member 16 having the I-shaped cross section.
Even if fl is extended in the vehicle width direction and bent vertically like the second embodiment shown in FIG. 5 and fastened to the side rail web 12w with rivets or bolts 14, substantially the same effect can be obtained. be able to.

Further, FIGS. 7 and 8 show a fourth embodiment of the present invention. In this embodiment, the upper members 16u and 16l having a hat-shaped cross section are integrally connected by a large number of rivets or bolts 22, and the upper member 16u and the lower member 16l are connected together.
The so-called alligator-type cross member 16 in which the ends in the width direction of the vehicle are opened in a V shape and the respective end members are bent in the vertical direction to form the mounting portions 16u 'and 16l' is adopted. The mounting portions 16u 'and 16l' are fixed to the web 12w of the side rail 12 by rivets or bolts 14, respectively.
Further, a gutter-shaped or groove-shaped fold-shaped portion 18 is formed in the plate portion between the rivets or the bolts of each mounting portion 16u 'and 16l'.

Even in this configuration, the durability and reliability of the chassis frame 10 are improved, and the structure is simplified, just as in each of the above embodiments.
It is clear that a reduction in manufacturing costs as well as a reduction in weight can be achieved.

In addition, in each of the above-described embodiments, the fold-shaped portion 18 formed at the coupling end of the cross member 16 to the side rail 12 is provided on all the plate portions between the rivets or the bolts 14,
The number is arbitrary, and for example, in FIG. 3, only one at the center or only two at both ends can be used.

(Effects of the Invention) As described above, the chassis frame of the truck according to the present invention includes a pair of left and right side rails extending in the front-rear direction of the vehicle body and both end portions of the side rails arranged in the vehicle width direction. A cross member fixed by rivets or bolts, characterized in that a fold-shaped portion extending in the vehicle width direction is formed in the plate portion between the rivets or bolts at the end of the cross member. In addition, since it is possible to provide an undercarriage frame having a simple structure and light weight, and excellent durability and reliability at low cost, it is extremely useful in practice.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part showing a first embodiment of a chassis frame according to the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1 and viewed in the direction of the arrow, and FIG. Cross member 16 in the figure
FIG. 4 is an enlarged plan view showing an end portion of FIG. 4, FIG. 4 is a plan view showing a second embodiment of a chassis frame according to the present invention, and FIG. 5 is an enlarged end portion of the cross member 16 in FIG. 6 is a side sectional view of a chassis frame according to a third embodiment of the present invention as viewed from the inside of the vehicle body, and FIG. 7 is a fourth embodiment of the chassis frame according to the present invention. FIG. 8 is an enlarged side view of the cross member 16 shown in FIG. 10 …… chassis frame, 12 …… side rails, 14 …… rivets or bolts, 16 …… cross members, 18 …… folds.

Claims (1)

[Scope of utility model registration request] 1. A set comprising a pair of left and right side rails extending in the vehicle front-rear direction, and a cross member arranged in the vehicle width direction and having both end portions fixed to the side rails by rivets or bolts. A chassis frame for a truck, characterized in that a fold-shaped portion extending in the vehicle width direction is formed in a plate portion between the rivets or bolts at the end of the cross member.