JPS61291272A - Frame for automobile - Google Patents

Abstract

PURPOSE:To allow a frame of a simple structure, which is entirely strengthened and is capable of reducing its twisting resonance, to be employed without impairing the arrangement of functional components by assembling a cross member, both sides of which are bent into a circular arc form, into an arch form across both a right and a left side member. CONSTITUTION:A cross member 10 which is transversally installed while it is extended, is bent to the same side into a circular arc form at its both ends 10a, and its center portion 10b is located above the space 4 between a right and a left side member 1 and 2, each of which is composed of an outer panel 11 in a U like shape and an inner panel 12 in a U like shape where an approximately retangular closed section is formed by these panels, and are extended to the longitudinal direction with respect to a body while they face each other. And the both ends 10a are fastened to the inner lower end of the right and left side members 1 and 2, that is, the lower end of the inner panel 12, by way of a bracket 7 of a leaf spring 8 allowing the cross member 10 to be assembled in an arch form across the right and left side member 1 and 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an automobile frame, and more particularly to an automobile frame comprising left and right side frames and a cross member bridging these.

Conventional technology Fig. 4 is a general external perspective view of a so-called ladder-shaped frame of this type of automobile frame. The left and right side members 1゜2 are extended in the width direction, and a plurality of cross members 3 are connected at both ends to extend in the width direction of the vehicle, forming a ladder shape. For example, in April 1980,
It is shown on page 28 of ``Complete Book of Automotive Engineering; Volume 13: Passenger Car Body'' published by Sankaido on March 20th.

By the way, as shown in FIG. 5, both ends of the cross member 3 are connected to the inner upper parts of the left and right side members 1 and 2, and the cross member 3 is placed above the space 4 between the left and right side members 1 and 2. For example, a propeller shaft 5 is disposed in a straight line, and a propeller shaft 5 is disposed in a portion of the space 4 below the cross member 3.
Functional parts such as a muffler and a muffler 6 are arranged, and the height of these functional parts from the ground is increased to protect the functional parts from flying stones and interference with the road surface during driving. In addition, 7 is fixed to the lower part of the left and right side members 1 and 2, respectively, and is the side member 1 that controls the left and right ends of the leaf spring 8 of the suspension.
, 2 are rotatably connected brackets, and 9 is a vehicle body floor.

Problems to be Solved by the Invention However, in the above-mentioned structure, even if the vertical width of the left and right side members 1 and 2 is increased in order to increase the strength against external forces such as thrusting, torsion, and vibration during driving, the functional parts cannot be In order to avoid this problem, the vertical width of the cross member 3 is small, so not only is it not possible to sufficiently increase the bending and torsion strength of the frame as a whole, but also the cross member 3 is stretched across the left and right side members 1 and 2 in a substantially straight line. Because the frame is placed in front of the vehicle, the frame is susceptible to resonance with vibrations from the engine and suspension, especially torsional resonance, and the vibrations amplified by this resonance are transmitted to the vehicle body, potentially causing vehicle body vibrations and muffled noise.

Therefore, the present invention provides an automobile frame that can increase the strength of the entire frame, reduce torsional resonance, and improve the sense of quality without impairing the arrangement of functional parts.

Means for Solving the Problems In the present invention, both ends of a cross member extending in the vehicle width direction are bent in an arc shape toward the same side, while the middle part of this cross member is bent in the vehicle width direction. The cross member is arranged above the space between the left and right side members facing each other and extending in the longitudinal direction of the vehicle body, and both ends of the cross member are connected to the inner lower part of the left and right side members. It is assembled in an arch shape across the left and right side members.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, with parts ζ having the same structure as the conventional structure being denoted by the same reference numerals.

In FIGS. 1 and 2, reference numeral 10 denotes a cross member extending in the vehicle width direction, and both ends 10a thereof are bent in an arc shape toward the same side. 10b has a substantially rectangular closed cross-section with a U-shaped outer panel 11 and a U-shaped inner panel 12 that is internally fitted and welded to the U-shaped outer panel 11 and is welded to the U-shaped outer panel 11. The cross member 10 is arranged above the space 4 between the left and right side members 1 and 2 extending toward the left and right side members 1 and 2, and both ends 10a of the cross member 10 are connected to the inner lower part of the left and right side members 1 and 2, that is, the inner panel 12. The cross member 10 is connected to the lower part of the web of the left and right side members 1 through the bracket 7 of the leaf spring 8.
, 2 are assembled in an arch shape. Reference numeral 13 denotes a damper component, such as a mass damper or a dynamic damper, attached to the intermediate portion tab of the cross member 10.

According to the structure of the above embodiment, the cross member 10 is assembled in an arch shape across the left and right side members 1 and 2, so that functions such as the propeller shaft 5 and the muffler 6 are placed below the cross member 10 in the space 4. In addition to being able to arrange the parts, since both ends t@1lQa of the cross member 10 are bent into an arc shape, the vertical width of the cross member 10 is formed to be approximately the same as the vertical width of the left and right sidemen/(-1, 2). This increases the bending and torsional strength of the entire frame, and when torsion is transmitted from the left and right side frames 1 and 2 to the cross member 10, the cross member 1
The damper effect due to the arch shape of 0 can damp torsion and reduce torsional resonance. Moreover, by connecting the mass and dynamic spring constant of the damper parts, the natural frequency of the cross member 10 is attenuated and superimposed on the resonant frequency of the entire frame, reducing the vibration of the entire frame and reducing the vibration transmitted from the frame to the vehicle body. It can also soften and reduce muffled sounds.

Furthermore, in the embodiment described above, the cross member 10 is connected to the left and right side members 1 and 2 via the brackets 7 of the leaf springs 8. When the above-mentioned bracket 7 is not present at the connecting part of the cross member 1, as shown in FIG.
Even if both ends 5ioa of the left and right side members 1 and 2 are directly connected to the lower webs of the inner panels 12 of the left and right side members 1 and 2, the same effect as in the embodiment described above can be obtained.

Effects of the Invention As described above, according to the present invention, the cross member having both ends bent into an arc shape can be assembled in an arch shape across the left and right side members, making it easy to assemble. Although it is a J-built construction, it is possible to increase the strength of the entire frame without compromising the placement of functional parts in the space between the left and right side frames, and to reduce torsional resonance, which reduces vibrations and muffles transmitted from the frame to the vehicle body. It has a practical effect of reducing sound and improving the sense of quality.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view taken along the vehicle width direction showing the greatest advantage of the present invention; Fig. 2 is a cross-sectional view taken along the It-11 line in Fig. 1;
The figures are cross-sectional views showing different examples of the present invention, FIG. 4 is a perspective view showing the general appearance of a ladder-shaped frame, and FIG. 5 is a cross-sectional view taken along the line ■-■ in FIG. 4. 1.2 - Left and right side members 1.3, 10... Cross member, 4... Space, 10 a... Both ends, t
a b...Middle cylinder 1 figure 3 figure 4 figure 5

Claims (1)

[Claims] Both ends of the cross member extending in the vehicle width direction are bent in an arc shape toward the same side, while the intermediate portions of the cross member are provided facing each other on both sides in the vehicle width direction and extending in the longitudinal direction of the vehicle body. The cross member is disposed above the space between the left and right side members, and both ends of the cross member are connected to the inner lower portions of the left and right side members, so that the cross member is assembled in an arch shape across the left and right side members. Automotive frame.