JPH07100454B2 - Truck undercarriage frame - Google Patents

Description

TECHNICAL FIELD The present invention relates to a chassis frame of a truck.

(Prior Art) An example of a conventional truck chassis frame will be described with reference to FIGS. 1 and 2 showing an embodiment of the present invention for the sake of convenience and with reference to FIG. . In the figure, reference numeral 10 generally indicates a chassis frame. The chassis frame 10 includes a pair of left and right side rails 12 extending in the front-rear direction of the vehicle body, each of which has a groove type (channel type) side rail 12, and a side rail 12 of the same side rail 12. Inserted inside the respective vertical flanges 14v and 16v on the side rail web 12w are a plurality of rivets or bolts 18u and 18v.
an upper gusset 14 and a lower gusset 16 each having an L-shaped cross section fastened by l, and a cross member 20 extending in the vehicle width direction and having a groove-shaped cross section. The cross member 20 has a plurality of rivets or bolts 2 at both end portions of the upper flange 20u and the lower flange 20l in the vehicle width direction to the corresponding lateral flange 14h of the upper gusset 14 and the corresponding lateral flange 16h of the lower gusset 16, respectively.
It is fastened by 2u and 22l.

1 and 2 exemplify a cross member 20 having a groove-shaped cross section, the same as the cross member having a I-shaped cross section and the upper member having a normal hat-shaped cross section. A so-called alligator-type cross member or the like in which a lower member fixed to at least both ends of the square member is formed, and a joint portion expanded in a V shape by the upper member and the lower member is formed at both end portions in the vehicle width direction. Is appropriately adopted.

The vertical flange 14v of the upper gusset 14 and the lower gusset 1
The arrangement of the rivets or bolts 18u and 18l for fastening the six vertical flanges 16v to the webs 12w of the side rails 12 is generally as shown in FIG. This figure is a front view of the vertical flanges 14v and 16v. XX is a horizontal center line, YY is a vertical center line, and O ₁ -O ₂ is an upper gusset.
14 vertical flange 14v and horizontal flange 14h joining line, O _{3 −} O ₄
Is the joining line between the vertical flange 16v of the lower gusset 16 and the horizontal flange 16h, and a ₁ to a ₂ and a ₃ to a ₄ are the longitudinal lengths of the vertical flanges 14v and 16v of the upper and lower gussets, that is, If the length of the joint lines O ₁ -O ₂ and O ₃ -O ₄ , d ₁ , d ₂ ,
d ₃ and d ₄ are vertical flange widths of the vertical flanges 14v and 16v at the ends of the joining line. In the conventional arrangement shown, the rivets or bolts 18u and 18l are aligned with the axis Y.
Six pieces are arranged symmetrically on both sides of -Y and substantially in line along the joining line of the upper gusset and the lower gusset.

During traveling of the truck, the chassis frame 10 is subjected to vertical bending, twisting, and lateral bending loads, and a combined load of these acts, so in order to increase the coupling force between the side rails 12 and the cross members 20, The rivets or bolts 18u and 18l for fastening the vertical flanges 14v and 16v of the upper gusset 14 and the lower gusset 16 to the web 12w of the side rail.
Have been conventionally most commonly located far away from the centerlines X-X and Y-Y.

(Problems to be Solved by the Invention) Upper and lower gussets 14 having an arrangement pattern of rivets or bolts 18u and 18l as shown in FIG.
For Nos. 16 and 16, the torsion test of the chassis frame was conducted focusing on the most important torsional load of the various loads acting on the chassis frame during traveling.
Triangular regions Ω _{1 to} Ω ₄ (these regions Ω _{1 to} Ω ₄
Will be described in more detail below), or significantly around the rivets or bolts 18u and 18l, or in other words, around the rivet or bolts that are located far from the intersection O _{0 of the} center lines X-X and Y-Y. If a large amount of stress is generated, and if the vehicle is repeatedly driven on a rough road, the rivets or bolts in the above area will break, or the side rail web 12w and vertical flanges 14v, 16v of the upper and lower gussets around the rivets or bolts will break. It was found that cracks tend to occur.

According to the present invention, the vertical flanges of the upper and lower gussets having an L-shaped cross section are fastened to the web of the side rail having the groove-shaped cross section by a plurality of rivets or bolts, respectively, and the lateral flange of the gusset is cross-membered. In an undercarriage frame formed by fastening the upper flange and the lower flange with a plurality of rivets or bolts, by adding a device to the arrangement of the rivets or bolts for fastening the vertical flanges of the upper and lower gussets to the side rail web, The purpose of the present invention is to reduce the stress generated by rivets or bolts while ensuring the torsion and bending rigidity, and to improve the durability strength of the upper and lower gusset fastening portions with respect to the side rails.

(Means for Solving the Problems) A chassis frame of a truck according to the present invention was created in order to achieve the above-mentioned object, and a pair of left and right cross-sectional shapes extending in the front-rear direction of the vehicle body are groove-shaped. A side rail, an upper gusset and a lower gusset each having an L-shaped cross-section, each vertical flange inserted inside the side rail and fixed to the web of the side rail by a plurality of rivets or bolts; A cross member fixed to the lateral flanges of the upper gusset and the lower gusset by means of a plurality of rivets or bolts, the two end portions of the upper and lower flanges extending in the same direction. The rivets or bolts that secure the vertical flange of the lower gusset to the web of the side rails are A region Ω _i (i = 1 to 4; i = 1 and 2 are upper gussets, i = 3 and 4 are lower gussets) satisfying the following equation, Where ξ _i is the coordinate in the direction along the joining line in the local coordinate system having the origin at both ends O _i of the joining line between the vertical and horizontal flanges of the upper and lower gussets η _i : The local origin with O _i as the origin Coordinates perpendicular to the joining line in the coordinate system a _i : Length of the joining line of the upper gusset and lower gusset d _i : At least one region of the length of the upper gusset and the lower gusset in the η _i direction It is characterized in that it is not disposed in the.

(Operation) According to the present invention, by twisting the upper and lower gusset joints with respect to the side rails by disposing a plurality of rivets or bolts in the flange surface of the vertical flanges of the upper and lower gussets excluding the regions Ω _{1 to} Ω _4. It is possible to reduce the stress generated in the rivet or bolt and its peripheral plate member while ensuring the rigidity, and improve the durability strength of the joint portion.

(Embodiment) An embodiment of the present invention will be specifically described below with reference to the accompanying drawings (note that matters already described in connection with the above-described conventional configuration will not be described again). In the first embodiment of the present invention shown in FIG. 3 to FIG. 3, the arrangement pattern of the rivets or bolts 18u and 18l for fastening the vertical flanges 14v and 16v of the upper gusset 14 and the lower gusset 16 to the web 12w of the side rail 12 is the first. This is clearly shown in Figure 3. As shown, the six rivets or bolts 18u located on the vertical flange 14v of the upper gusset 14 are all located within the flange plane except the triangular areas Ω ₁ and Ω ₂ shown by hatching in the figure. ing. Similarly downward gusset 16
The six rivets or bolts 18l arranged on the vertical flange 16v of the are the shaded triangular areas Ω ₃ and Ω ₄
All are arranged in the flange surface except for.

The area Ω ₁ is one end of the joining line O ₁ -O ₂ between the vertical flange 14v and the horizontal flange 14h of the upper gusset 14, for example, the front end O.
_In the local Cartesian coordinate system with ₁ as the origin, the joining line O ₁ −O ₂
When the coordinate in the direction along is ξ ₁ and the coordinate in the direction orthogonal to the joining line O ₁ -O ₂ is η ₁ , A region Ω ₂ is a slender triangular region represented by the following equation, and the region Ω ₂ is also the other end portion of the above joining line O ₁ -O ₂ , for example, the rear end.
In the local Cartesian coordinate system with O ₂ as the origin, the joining line O ₁ −O ₂
When the coordinate in the direction along is ξ ₂ and the coordinate in the direction orthogonal to the joining line O ₁ -O ₂ is η ₂ , Is a slender triangular region that satisfies As shown,
In the lower gusset 16 as well, the connection line O ₃ -O ₄ between the vertical flange 16v and the horizontal flange 16h is exactly the same. as well as The triangular areas satisfying the above are set respectively.

As already mentioned, in the previous configuration shown in FIG.
Vertical flanges 14v and 16v of upper and lower gussets 14 and 16
When the same region Ω _{1 to} Ω ₄ as shown in FIG. 3 is set on the upper side, the center line of the three upper and lower rivets or bolts 18u and 18l arranged on the left side of the center line YY is the same center line. Each of the two rivets or bolts on the side remote from is at least partially contained in these areas in cross section.

Now, in the upper part of FIG. 4, a diagonal line drawing of the upper gusset 14 and the lower gusset 16 is drawn, and the vertical flanges 14v and 16v thereof are drawn.
Above, in the direction parallel to the center line XX (front-back direction of the vehicle body), it is far from the center line, that is, the joining lines O ₁ -O ₂ and
The upper and lower rows A close to O ₃ -O ₄ and the upper and lower rows B close to the same center line, that is, the joining lines O ₁ -O ₂ and O ₃ -O ₄ and the center line Y-
A rivet or bolt arrangement pattern is shown which is composed of the first row closest to the center line, the second row in the middle, and the third row farthest from the center line in the direction parallel to Y (vertical direction). Also, in the middle of the figure, the stress sensitivity (kgf / mm ² / kgf ・ m) and torsional rigidity (kgfm) to the torsional moment of the vertical flange joint when the arrangement positions of the rivets or bolts 18u and 18l are variously changed. ² ) data is shown. In this data, the symbol ○ (white circle) indicates the stress sensitivity of the gusset joint,
The symbol Δ (white triangle) indicates torsional rigidity. Finally, the lower part of the figure shows rivets or bolts 18u and 1
A schematic diagram showing four types of 8 l arrangement patterns Pa # 1 to Pa # 4 and specific rivet or bolt positions is described.

The arrangement pattern of the conventional rivets or bolts 18u, 18l shown in FIG. 10 corresponds to the pattern Pa # 1 in FIG. 4, and corresponds to the joint lines O ₁ -O ₂ and O ₃ -O ₄ in the row A. Rivets or bolts are placed on all of the first, second and third rows, namely A ₁ , A ₂ , A ₃ . The pattern Pa # 2 of FIG. 4 is equivalent to the first embodiment of the present invention shown in FIG. 1 to FIG. 3, the bonding lines O ₁
The A Example Nearby -O ₂ and O ₃ -O _4, rivets or bolts are arranged only on the center line Y-Y nearest first row (and therefore A _1), the farther from the center line Y-Y 2 row and the third row is far B column from the junction line O ₁ -O _2, and O ₃ -O _4, i.e. B _2, the B ₃ respectively rivets or bolts are arranged. With pattern Pa # 1
Comparing with Pa # 2, there is not much difference between them in the torsional rigidity of the gusset vertical flange, but it is shown that the stress sensitivity of the pattern Pa # 1 is much higher than that of Pa # 2. Therefore, if the high-speed traveling such harsh running on rough road is performed repeatedly, the coupling portion of the conventional upper and lower gusset, the maximum stress is generated in the farthest A ₃ position of the rivets or bolts from the center line Y-Y However, the rivet or bolt is broken, the side rail web 12w around the rivet or bolt or (and) the vertical flange 14v, 1 of the gusset
6v cracks are likely to occur, but the pattern Pa # 2 according to the present invention
In the above configuration, since the stress sensitivity is remarkably low, the durability strength of the upper and lower gusset joints is remarkably improved, and the risk of breakage of the rivet or bolt and the surrounding side rail web and / or the gusset vertical flange is extremely small, It has the advantage of being reliable.

Next, in the pattern Pa # 3 in FIG. 4, the six rivets or bolts 18u and 18l of the upper and lower gussets belong to the regions Ω ₁ and Ω ₂ , Ω ₃ and Ω ₄ , respectively. This is a modification in which each row of columns B, that is, B ₁ , B ₂ , and B ₃ distant from the joining lines O ₁ -O ₂ and O ₃ -O ₄ , respectively, are arranged so as not to exist. Also in this modification, substantially the same as the pattern Pa # 2,
It is clear from the test results that the stress sensitivity of the joint between the vertical flange of each gusset and the side rail web can be reduced while ensuring sufficient torsional rigidity. Further, the pattern Pa # 4 in FIG. 4 has four rivets or bolts for each of the upper and lower gussets arranged in the first row of column A and the second row of column B, that is, A ₁ and B ₂ , respectively. FIG. 6 shows another modification in which the rivets or bolts are arranged in a circle or an ellipse as a whole, and all these rivets or bolts are not included in any of the regions Ω _{1 to} Ω ₄ . Also in this modified example, the stress sensitivity of the conventional structure, that is, the torsional rigidity of the vertical flange joints of the upper and lower gussets, which is substantially the same as that of the patterns Pa # 2 and Pa # 3, is ensured.
There is an advantage that it can be significantly reduced compared to Pa # 1, and thus the durability and reliability of the joint portion can be effectively improved.

Next, FIG. 5 shows upper gussets 14 and 16 having an L-shaped cross section for connecting the ends of the upper and lower flanges 20u and 20l of the cross member 20 having a groove-shaped cross section to the side rail 12, respectively.
Both vertical flanges 14v and 16v are arranged downward and fastened to the web 12w of the side rail by rivets or bolts 18u and 18l, and FIG. 6 shows the first modified example. On the contrary, the upper gussets 14 and 16 having an L-shaped cross-section have the vertical flanges 14v and 16v arranged upward, respectively, fastened to the web 12w of the side rail by the rivets 18u and 18l. It shows a modified example, and all other configurations are substantially the same as the first modified example.

Also in these first and second modified examples, the joining lines O ₁ -O ₂ and O ₃ -O ₄ of the vertical flanges 14v and 16v of the upper and lower gussets 14 and 16 and the horizontal flanges 14h and 16h, respectively, Similar to the embodiment, the same regions Ω _{1 to} Ω ₂ are set as the horizontal axis of the local Cartesian coordinate system, and the rivets 18u and 18v are formed in the planes of the vertical flanges 14v and 16v excluding Ω ₄ in these regions Ω ₁ . 18l
By arranging the above, the patterns of the first embodiment shown in FIG.
(Including the arrangement corresponding to 4), the stress sensitivity of the upper and lower gussets can be remarkably reduced as compared with the conventional structure while ensuring sufficient torsional rigidity in the vertical flange joints. The durability and reliability of can be improved.

Next, FIG. 7 shows that the cross member 20 is formed as a member having an I-shaped cross-sectional shape consisting of upper and lower flanges 20u and 20l and a vertical web 20w.
It is a second embodiment of the present invention which is substantially equivalent to the embodiment. In this embodiment, the upper and lower flanges 20u and 20l of the cross member 20 are riveted or bolted 22u to the lateral flanges 14h and 16h of the upper gusset 14 and lower gusset 16, respectively.
And 22l, and the vertical flanges 14v and 16v of the upper gusset 14 and the lower gusset 16 are fastened and fixed to the web 12w of the side rail 12 by rivets or bolts 18u and 18l. Also in this fourth embodiment, the vertical flanges 14v and 16v of the upper gusset 14 and the lower gusset 16 are also provided.
And the rivets or bolts 18u and 18l for fastening the web rail 12w of the side rail 12 to the vertical flanges 14v of the upper and lower gussets 14 and 16, as in the first embodiment and its modification.
By arranging on the vertical flange surface other than the area Ω _{1 to} Ω ₄ in the local Cartesian coordinate system with the horizontal axis being the joining lines O ₁ -O ₂ and O ₃ -O ₄ between the 16v and the horizontal flanges 14h and 16h, Similar to the first embodiment, the stress sensitivity of the joint between the upper and lower gussets and the side rails is sufficiently ensured while the torsional rigidity of the joint is sufficiently secured, and the durability and reliability of the joint are improved. Can be improved. The vertical flanges 14v and 16v of the upper and lower gussets 14 and 16 in this embodiment may be arranged so as to face each other as shown in FIG. 2 or may be arranged so as to face downward as shown in FIG. Alternatively, both may be arranged so as to face upward as shown in FIG.

Furthermore, FIGS. 8 and 9 show a third embodiment in which the present invention is applied to a chassis frame 10 including a so-called alligator type cross member 20.
It relates to an example. Alligator cross member
The upper member 20a having a hat-shaped cross section and the lower member 20b having a flat plate (in the case of the drawing) or a hat shape or any other desired cross-sectional shape are integrally formed by a plurality of rivets or bolts 24. It is composed by combining. An upper flange 20u and a lower flange 20l which form a V-shaped joint portion are formed at both ends of the cross member 20 in the vehicle width direction.
Is provided. The upper and lower flanges 20u and 20l of the cross member 20 are formed by the upper gusset 14 and the lower gusset 16 respectively.
Fixed to the lateral flanges 14h and 16h of the rivet 22u and 22l, respectively, and also to the upper gusset 14 and the lower gusset.
The 16 vertical flanges 14v and 16v are rivets or bolts, respectively.
It is fastened to the web 12w of the side rail 12 by 18u and 18l.

Install the rivets or bolts 18u and 18l above the upper gusset 14
And vertical gusset 16 vertical flanges 14v, 16v and horizontal flange 1
By arranging them respectively in the vertical flange planes that do not belong to the regions Ω _{1 to} Ω ₄ in the local orthogonal coordinate system having the joining lines O ₁ -O ₂ and O ₃ -O ₄ with 4h and 16h as the horizontal axis, Similar to each of the above-mentioned embodiments and their modifications, the stress sensitivity of the joint between the upper and lower gussets and the side rails is remarkably reduced as compared with the conventional structure while the torsional rigidity is sufficiently ensured, and the durability of the joint is improved. The reliability and reliability can be significantly improved. Of course, the upper and lower gussets 14 and 16 in this embodiment
The vertical flanges 14v and 16v may be arranged opposite to each other as shown in FIG. 9 or face each other as shown in FIG. 2 or both as shown in FIG. Alternatively, as shown in FIG. 6, both may be arranged facing upward.

In all of the above-described embodiments and their modifications, the number of rivets or bolts for fastening the upper and lower gussets to the side rail webs can be increased or decreased as appropriate, and the vertical flanges of the upper and lower gussets can be The front shape is not limited to the illustrated rectangle, but may be a trapezoid.

(Effects of the Invention) As described above, the undercarriage 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 having groove-shaped side rails, and inside the side rails. An upper gusset and a lower gusset each having an L-shaped cross-section, each of which is inserted and each vertical flange is fixed to the web of the side rail by a plurality of rivets or bolts;
The upper member of the upper gusset and the lower gusset having a cross member fixed to the lateral flanges of the upper gusset and the lower gusset by means of a plurality of rivets or bolts at both end portions of the upper and lower flanges extending in the vehicle width direction. A region where a plurality of rivets or bolts for fastening the vertical flanges of the gusset and the lower gusset to the web of the side rail satisfy the following formula in the vertical flange of each gusset Ω ₁ (i = 1 to 1
4; i = 1 and 2 are upper gussets, i = 3 and 4 are lower gussets) Where ξ _i is the coordinate in the direction along the joining line in the local coordinate system with the origin at both ends O _i of the joining line between the vertical and horizontal flanges of the upper and lower gussets η _i : Local with the above O _i as the origin Coordinates perpendicular to the joining line in the coordinate system a _i : Length of the above joining line of the upper gusset and lower gusset d _i : At least one of the regions of the length of the upper gusset and the lower gusset in the η _i direction It is characterized in that it is not arranged in the area, and by devising the arrangement pattern of rivets or bolts arranged on the vertical flanges of the upper and lower gussets that fix both end portions of the cross member to the side rails, While ensuring the torsional and bending rigidity of the gusset joint, the stress generated in the rivet or bolt and the plate member around it is effectively reduced, and the durability of the gusset joint is improved. And there is an advantage that can improve the reliability,
It is extremely beneficial in industry.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part showing a first embodiment of the present invention, FIG. 2 is a front view as seen from the direction of arrow II in FIG. 1, and FIG. 3 is an upper part shown in FIGS. And FIG. 4 is a front view showing an arrangement pattern of rivets or bolts on the vertical flanges of the lower gussets, and FIG. 4 shows conventional torsional rigidity and stress sensitivity at the joint between the upper gusset and the lower gusset and the side rail web in the first embodiment. 5 and 6 are front views similar to FIG. 2 showing modified examples of the first embodiment, and FIG. 7 is a second embodiment of the present invention. FIG. 8 is a plan view of relevant parts showing a third embodiment of the present invention, FIG. 9 is a front view as seen from the direction of arrow IX in FIG. 8, and FIG. A conventional rivet or bolt placement pattern for the upper and lower gussets of the chassis frame similar to the example It is to front view. 10 ... chassis frame, 12 ... side rail, 12w ... side rail web, 14 ... upper gusset, 14v ... upper gusset vertical flange, 16 ... lower gusset, 16v ... lower gusset vertical flange, 18u and 18l ... rivet or bolt, 20… Cross member.

Claims (1)

[Claims] 1. A pair of left and right side rails extending in the front-rear direction of the vehicle body each having a groove-shaped cross-section, and respective vertical flanges inserted inside the side rails, each vertical flange being provided with a plurality of rivets or bolts. The upper gusset and the lower gusset each having an L-shaped cross section fixed to the web, and the upper and lower gussets extending in the vehicle width direction are provided with the upper gusset and the upper and lower flanges at both ends by a plurality of rivets or bolts. A cross member fixed to the lateral flange of the lower gusset, wherein a plurality of rivets or bolts for fastening the vertical flanges of the upper gusset and the lower gusset to the web of the side rail are provided in the vertical flange of each gusset. Area that satisfies the following formula of Ω
_i (i = 1 to 4; i = 1 and 2 are upper gussets, i = 3 and 4 are lower gussets), ie Where ξ _i is the coordinate in the direction along the joining line in the local coordinate system having the origin at both ends O _i of the joining line between the vertical and horizontal flanges of the upper and lower gussets η _i : The local origin with O _i as the origin Coordinates in the direction perpendicular to the joining line in the coordinate system a _i : Length of the joining line of the upper gusset and lower gusset d _i : At least one region of the length of the upper gusset and the lower gusset in the η _i direction Undercarriage frame of a truck characterized by not being provided