JPH02274672A - Under carriage frame with baggage box - Google Patents

Abstract

PURPOSE:To improve durability, achieve lightweight and reduce the cost by disposing a group of rivets or bolts in such a way that the distance between the equivalent center of gravity of the group of rivets or bolts disposed on the upper side of the lateral center line of a gusset web and the center line of each rivet or bolt satisfies a specific equation. CONSTITUTION:The distance between the equivalent center of gravity (gu) of a group of rivets 24u disposed on the upper side of the lateral center line N-N of a gusset web 14w, among the rivets for fastening the web 14w of a gusset 14 to the web of a side rail, and the center line of each rivet 24u is made (rui). The distance between the equivalent center of gravity (ge) of a group of rivets 24 disposed on the lower side of the lateral center line N-N and the center line of each rivet 24e is made (rei). The groups of rivets 24u, 24e are disposed in such a way as to satisfy an equation I. The generating stress of each of the rivets 24u, 24e is thereby uniformed so as to improve the durability of the fastening part of a gusset 14.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a chassis frame for a vehicle, such as a truck, equipped with a cargo box.

(Prior art) A normal truck has a pair of left and right side rails extending in the longitudinal direction of the vehicle body and having a groove-shaped cross section, and a plurality of side rails arranged in the width direction of the vehicle and having both ends fixed to the side rails. The vehicle is equipped with an undercarriage frame consisting of a cross member, and a cargo box is mounted on the undercarriage frame. The vertical joists or subframes of the cargo box are fastened to the side rails by fastening means such as U-bolts.

Members having a groove-shaped or one-shaped cross-sectional shape are widely used as the cross members, and both end portions of these cross members in the vehicle width direction are often connected to the side rails via gussets. Further, as the above-mentioned gusset, those having a groove-shaped cross section are widely used.

(Problems to be Solved by the Invention) When a vehicle such as a truck is used in severe conditions, such as when a loaded vehicle is traveling at high speed on a rough road with severe unevenness, a large torsional load acts on the chassis frame. A large stress is generated in the gusset as an intermediate member that fastens the cross member to the side rail, and in the rivet or bolt that fixes the gusset to the side rail.

In the conceptual side view of FIG. 9, the chassis frame, generally designated by the reference numeral 10, includes a gusset 14 having a groove-shaped cross-section and a web of a pair of left and right side rails 12 having a groove-shaped cross-section. The upper flange 14u of the gusset 14 is joined by a plurality of rivets or bolts.
And the upper flange 16u and lower flange 1 of the cross member 6 having a groove-shaped cross section are attached to the lower flange 14t.
6 and 6 are of a normal structure, each of which is fastened with a plurality of rivets or bolts. When a torsion test was conducted on this chassis frame 10, it was found that, in the case of the illustrated chassis frame alone, the upper flange 16u and lower flange 16t of the cross member 6 had approximately the same size as shown by arrows S and St in the figure, respectively. As shown in the conceptual side view of FIG. When mounted and tightened and fixed using fixing means 22 such as U bolts, arrow Su' in the figure
It has been found that a much larger shearing force in the longitudinal direction of the vehicle body acts on the lower flange 16t than that on the upper flange 16u of the cross member 6, as shown by SL and SL. This test result shows that in a normal truck chassis frame in which a cargo box 20 is mounted on the chassis frame 14, the upper flange 16u and lower flange 16t of the cross member 16 are the 11th factor, and the gusset 14 shown in an enlarged front view is The corresponding upper flange 14u and lower flange 147 are fastened with rivets or bolts 1, and the gusset 14 is
The lippets 24u and 241 (or equivalent bolts) for fastening the web of the gusset to the web of the side rail 12 are installed in substantially the same pattern above and below the horizontal center line N-H of the web of the gusset. The previous arrangement was structurally unreasonable, and a larger stress was generated in the rivet 24t (or bolt) placed below the horizontal center line N-N than in the rivet 24u (or bolt), as described above. If you repeatedly drive under such harsh conditions, the lower side (7) IJ Pet 2
4t (or bolt) and the adjacent web plates of the gusset 14 and side rail 12 have a problem in that strength defects are likely to occur. In view of the above circumstances, the present invention has been developed by By making special arrangements for the rivets or bolts that fasten the web of the gusset connected to the side rail to the web of the side rail, the shearing force generated in these rivets or bolts in the longitudinal direction of the vehicle body can be equalized. It is an object of the present invention to provide a vehicle chassis hood with a cargo box that can improve the durability of the chassis frame and at the same time achieve reductions in weight and manufacturing costs.

(Terminology) In this specification, the term "equivalent center of gravity" with respect to a plurality of rivets or bolts that fasten the web of the gusset to the web of the side rail has the following meaning. That is, in FIG. 8, the transverse elastic modulus of an arbitrary number (two or more) of rivets or bolts R1, R2...R1...Rn-, Rn is determined by G1. G2...Gl...Gn-1
``n'' Each sled has the coordinate vector of the bolt r1nr
2...ri...rn-1, the coordinate vector r-1 of the equivalent center of gravity 9 (Means for solving the problem) The vehicle chassis frame with a cargo box according to the present invention achieves the above object. It was invented in A gusset fixed to the web of the rail and having a groove-shaped cross-section, and a cross member disposed in the width direction of the vehicle and having a groove-shaped or type 1 cross-section,
Both end portions of the upper and lower flanges of the Talosmenpa are respectively fastened to the corresponding upper and lower flanges of the gusset by a plurality of rivets or bolts, and the undercarriage frame is mounted on the undercarriage frame. In the case where the cargo box is fastened to the side rail by means of bolt fixing means, among the rivets or bolts that fasten the web of the gusset to the web of the side rail, the rivet or bolt is located above the lateral center line of the gusset web. Let rui be the distance from the equivalent center of gravity g of the placed rivet or bolt group to the center line of each rivet or bolt, and satisfy the equivalence of the rivet or bolt group placed below the lateral center line of the gusset web. The present invention is characterized in that the rivets or bolts described above are arranged as shown in FIG.

(Function) According to the present invention, the rivet (or bolt) that fastens the web of the gusset that connects both end portions of the cross member to the side rail and the cube of the side rail is arranged so as to satisfy the above formula. By doing so, the stress generated in each of the rivets (or bolts) is equalized, and the durability of the gusset fastening portion is improved.

(Example) Examples of the present invention will be specifically described below with reference to FIGS. 1 to 7. First, in the first embodiment of the present invention shown in FIGS. 1 to 3, the chassis frame 10 has a pair of left and right side rails 12 extending in the longitudinal direction of the vehicle body and having a groove-shaped cross section. A plurality of glue propellers (24u and 2) arranged in a pattern to be detailed later on the web 12w of the side rail.
Web 1 by 4/S (or substantially equivalent bolt)
A plurality of rivets 26u are attached to the groove-shaped gusset 14 to which the 4W is fixed, and the ends of the corresponding upper flange 16u and lower 7-lanzo 16t in the vehicle width direction are attached to the upper flange 14u and lower flange L4t of the gusset, respectively. and 26
The cross member 16 has a groove-shaped cross section and is fastened by bolts (or bolts with the same effect).

As shown in the enlarged front view of FIG.
On the web 14W of No. 4, the above-mentioned repets 241 are disposed in number nu (in this embodiment, four as an example) above the lateral center line N-N.

Also, the above rivet is placed below the center line N-N)24. % is nz
lvA (in this embodiment - six as an example) are arranged. Generally, the rivets 244 and 24u are of the same effective diameter, and the numbers nu and nz are as follows when the chassis frame is twisted, as already explained with regard to the 10th chassis frame with cargo box. Shearing forces Su′ and S! in the longitudinal direction of the vehicle body acting on the upper flange 16u and lower 72nd flange 16t of the cross member 16, respectively. ! It is set to adapt to.

Lippet located above the center line N-N) 24
Let rui be the distance from the equivalent center of gravity gu of group u to the center line of each ribet) 24u, and from the equivalent center of gravity gl of the group to each lipet) 24L located below the center line N-N. When the distance to the center line of is rt□, each rivet group is arranged according to the following formula. The shearing forces Su' and Sno acting on the upper flange 16u and lower flange 16t of the cross member 16 are
0 itself, the torsional rigidity of the cargo box 20, and the constraint conditions between the chassis 7 frame 1O and the cargo box 20. The sum of the rui of the group and mainly the shear force S/
The ratio α of the lower rivet 24 affected by the rti of the group to the sum of rti of the group is appropriately determined within the range of 1.2 to 4 depending on the characteristics of each vehicle. The reason for setting the above ratio α to 1.2 or more is that when α = 1.1, there is little improvement in durability compared to the conventional configuration where α = 1.0, but by setting α = 1.2, α = This is because durability more than twice that of 1.0 can be obtained. In addition, the reason why the above ratio α is set to 4 or less is that when α is set to 4, the ratio of improvement in durability is small compared to the increase in the number of man-hours for fastening rivets (or built-ins), and there is little benefit. .

By selecting the ratio α of the total center distance to an appropriate value between 1.2 and 4, the upper rivet 24u group and the lower rivet 24 are arranged so that the strength of each rivet in the group is approximately equal and there is no excess or deficiency. As a result of this,
There is an advantage that the durability and reliability of the web connection portion between the gusset 14 and the side rail 12 can be effectively improved, and of course the same is true when bolts are used instead of rivets. Also, as many rivets as necessary 24u and 241
Since the number of rivets can be reduced compared to the conventional method, the number of man-hours required for rivets can be reduced and manufacturing costs can be reduced. Furthermore, since there is no problem such as large stress occurring in some rivets and damage to the plate material of the gusset web 14W or (and) the side rail web 12W adjacent to the rivet, the reinforcing plate that has been often used in the past can be avoided. It is possible to eliminate or minimize the need for mounting, and from this point of view there is an advantage that weight and manufacturing costs can be reduced.

FIG. 4 shows the seven-nod web 14 in the first embodiment.
This shows a second embodiment of the present invention in which the arrangement pattern of the rivets (or built-ins) on the web 14W is changed. 244 is arranged in a substantially symmetrical downwardly convex shape with respect to the longitudinal centerline M-M.

Rivet 24u located above the horizontal center line N-N
Distance ru from the group's equivalent center of gravity to the center line of each rivet
The ratio α between the sum total of i and the sum total of distance rti from the equivalent center of gravity yt of the group to the center line of each rivet for the rivets 24 arranged below the concentric line N-N is Similarly, it is selected appropriately depending on the characteristics of the individual vehicle. This embodiment also achieves equalization of the stress generated in each rivet of both rivet groups, thus improving the durability of the joint between the gusset 14 and the side rail 12, and reducing weight and manufacturing costs. can do.

Further, FIGS. 5 and 6 show a third embodiment of the present invention,
In this embodiment, the webs of two groove-shaped members are brought into contact with each other back to back and are integrally connected by a number of rivets 28 to form a cross member 16 having a single-shaped cross-section. The Talos member has rivets 26 attached to the upper flange 16u and lower flange 16t to the upper flange 14u and lower flank L4t of the gusset 14, respectively.
They are connected by u and 26t (or bolts of the same effect, respectively). The web 14W of the gusset 14 is attached to the web 12w of the side rail 12 with an i! Lipets placed in turns) 24u and 24
(or bolts with the same effect).

As in the first and second embodiments, the gusset web 14
lateral centerline N-N upper ridge of w) From the equivalent center of gravity of the 24u group, the center of each rivet #j! and the equivalent center of gravity of the rivet 241 group below the center line N-N! The ratio α of the sum of distance rti from it to the center line of each rivet is appropriately selected in the range of 1.2 or more and 4 or less depending on the torsional rigidity of the chassis frame 10 and the cargo box 2o. The above-mentioned first And substantially the same effects as the second embodiment can be obtained. Also the 6th
Instead of the cross member shown in the figure, as shown in Fig. 7,
The plate material forming the upper flange 16u and the lower flange 1
It is possible to use a cross member 16 having a welded cross section formed by welding together a plate material forming the web 6t and a plate material forming the web 16w, and the cross member 16 is substantially equivalent in this case as well.

(Effects of the Invention) As shown in the drawings, the chassis frame with a cargo box according to the present invention has a pair of left and right side rails extending in the longitudinal direction of the vehicle body and each having a groove-shaped cross section, and a pair of side rails on the inside of the side rails. A gusset whose cross-sectional shape is a groove shape, which is inserted and whose web is fixed to the web of the side rail by a plurality of rivets or bolts, and a cross member which is arranged in the width direction of the vehicle and whose cross-sectional shape is a groove shape or a type 1. an undercarriage frame in which both end portions of the upper flange and lower flange of the Talos member are respectively fastened to the corresponding upper and lower flanges of the gusset by a plurality of rivets or bolts, and a Uyjr bolt mounted on the undercarriage frame. or the like, in which the rivet or built-in which fastens the web of the gusset to the web of the side rail is located above the lateral center line of the gusset web. The distance from the equivalent center of gravity g1 of the placed rivet or built group to the center line of each rivet or built is rui, and from the equivalent center of gravity g6 of the rivet or built group placed below the lateral center line of the gusset web. When the distance to the center line of each rivet or build is defined as rt, the above-mentioned group of rivets or builds are arranged, which improves the durability and reliability of the joint between the side rail and the gusset in the chassis frame with a cargo box. It is industrially beneficial because it can effectively improve performance and reduce weight and installation costs at the same time.

[Brief explanation of drawings]

FIG. 1 is a plan view (center plane 0-
0 left side) and bottom view (center line 0-0 right gl!l),
2 is a front view showing the gusset 14 extracted from FIG. FIG. 2 shows a second embodiment of the invention; a front view of the same gusset 14; FIG. 5 shows a third embodiment of the invention; 0-0 right side), FIG. 6 is a sectional view of the cross member 16 in FIG. 5, FIG. 7 is a sectional view similar to FIG. 6 showing a modification of the cross member 16 in FIG. 5, and FIG. A diagram illustrating the equivalent center of gravity I of a rivet or built group; FIG. 9 is a conceptual side view showing the mode of shearing force acting on the upper and lower flanges of the cross member when the chassis frame alone is twisted; Figure 10 is a conceptual side view similar to Figure 9 when the chassis frame with cargo box is twisted, Figure 11 is the gusset 1 in Figure 9 and Figure 10.
Fig. 4 is a front view of a gusset showing the conventional arrangement of rivets fastened to the gusset. 10... Chassis frame, 12... Side rail, 1
4...Gusset, 16...Cross member, 18...
・Liner, 20...Vertical joist or subframe. Fang 4 figure O 6 figure off figure

Claims (1)

[Claims] A pair of left and right side rails that extend in the longitudinal direction of the vehicle body and each have a groove-shaped cross-section, and a cross-sectional shape that is inserted inside the side rail and whose web is fixed to the web of the side rail with a plurality of rivets or bolts. a groove-shaped gusset, and a cross member disposed in the width direction of the vehicle and having a groove-shaped or I-shaped cross-section, and both end portions of the upper flange and lower flange of the cross member are provided with a plurality of rivets or bolts, respectively. a vehicle chassis frame fastened to corresponding upper and lower flanges of the gusset, and a cargo box mounted on the vehicle chassis frame and fastened to the side rails by fixing means such as U-bolts, Among the rivets or bolts that fasten the web of the gusset to the web of the side rail, the distance from the equivalent center of gravity g_u of the group of rivets or bolts placed above the lateral center line of the gusset web to the center line of each rivet or bolt. When the distance is r_u_i and the distance from the equivalent center of gravity g_l of the rivet or bolt group placed below the lateral center line of the gusset web to the center line of each rivet or bolt is r_l_i, 1.2≦Σ ^(n
_u)_i_=_1r_l_i/Σ^(n_u)_i_
A vehicle chassis frame with a cargo box, characterized in that the above rivets or bolt groups are arranged so as to satisfy =_1r_u_i≦4.