JPS6144922Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a closed cross-section frame constituting a side member or a cross member of an automobile.

In this type of frame, generally, an opening in one frame with a U-shaped cross section is fitted into an opening in the other frame with a U-shaped cross section, and welded at a position along the opening edge of the outer frame. In this case, if the entire inner frame is fitted into the outer frame and welded at the opening edge of the outer frame to form a closed cross-section frame, the welded part that causes stress concentration will be placed on the upper or It will come to the bottom. On the other hand, if the outer frame and inner frame are fitted and welded at a position where their open ends slightly overlap, the weld will be located near the neutral axis of frame bending, and the maximum stress position can be avoided. However, there is a problem in that it is difficult to position both frames when welding.

Therefore, the present invention locates the welded part near the neutral axis of the frame to avoid stress concentration at the welded part, and also makes it easy to position both frames at the welded part. The present invention provides a closed cross-section frame that can be constructed of:

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments. Figure 1 shows one side of the U-shaped cross-section frame that constitutes the closed cross-section frame.
A is made of a steel plate, and a step portion 11a bent outward is formed at the side edge of the U-shaped opening 2.
As shown in FIG. 2, the pair of U-shaped cross-sectional frames 1a and 1b are reversed in their longitudinal directions so that their openings face each other, and the side without the step of frame 1b is placed inside the step 11a of frame 1a. If the side edges of the frame 1a without a step are overlapped on the inside of the step 11b of the frame 1b and welded along the overlapping edges, the welding part 3 will be located approximately in the middle of the resulting closed cross-section frame. Located on the vertical axis.

However, since the frame of the present invention is used as a beam and the welded part is located almost at the neutral axis of bending, when used as a cross member or side member of an automobile,
It is possible to avoid applying the maximum stress to the welded portion under vertical bending loads. Furthermore, since both U-shaped cross-sectional frames are opposed to each other by the stepped portion, positioning of both frames during welding is easy. Furthermore, since both U-shaped cross-sectional frames are of the same type, productivity is good, and the closed cross-sectional frame is vertically and horizontally symmetrical, making it easy to assemble.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention; FIG. 1 is a sectional view of one U-shaped cross-sectional frame, and FIG. 2 is a perspective view of a closed cross-sectional frame. 1a, 1b...U-shaped cross-sectional frame, 11a,
11b...Step part, 2...Opening part, 3...Welding part.

Claims (1)

[Scope of utility model registration request] In a closed cross-section frame for an automobile, which is formed by welding a pair of U-shaped cross-section frames, the pair of frames with a step formed along one side edge of the U-shaped cross-section opening are reversed in the longitudinal direction. The openings are made to face each other, and the side edge of the other frame without the step is overlapped with the step of the other frame, and the side edge of the one frame without the step is overlapped with the step of the other frame. A closed-section automobile frame that is welded along the mating edges.