JPS5992166A - One-side welding method - Google Patents

Abstract

PURPOSE:To decrease the stress concentration at the point where a crack begins and to extend a fatigue life by using a non-weldable backing strip to form a rack part by fillet welding to the 1st member, pressing the 2nd member to the rack part to form a space part and welding the space part. CONSTITUTION:A non-weldable backing strip, for example, a copper back 12, is pressed to the position on the side face 10a of the 1st member 10 to which the 2nd member is to be welded. The corner part between the back 12 and the 1st member 10 is fillet welded to form a rack part 13. The back 12 is removed by hammering from the 1st member 10, and the rack part 13 corresponding to a conventional back plate is allowed to remain in the 1st member 10. The 2nd member 11 is pressed to the contact surface 13a in the part 13 and the space part 14 enclosed by the side face 10a of the member 10, the part 13 and the end face 11a of the 2nd member 11 is welded to form a weld zone 15.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single-sided welding method in which two members are butted together and fixed by single-sided welding.

Conventionally, as shown in FIG. 1, this type of single-sided welding method involves temporarily attaching the back plate 2 to the side surface 1α of the first member 1 by welding (a), and applying the second member 3 to the back plate 2. At the same time, the space 4 surrounded by the side surface lα of the first member 1 and the end surface 3α of the back plate 2 and second member 3 is welded from one side (b) to connect the first member 1 and the second member 3. As shown in Fig. 2, a welding method in which the pack plate 1-2 is welded by simply butting it together without welding it temporarily (a) is known.

However, no matter which welding method is used, the back plate 2
has a square cross section, so when the cart is applied, the crack starting point (the contact area between the horizontal member 3 and the back plate 2, the contact corner between the back plate 2 and the side surface 1α of the first member 1) N. This has the disadvantage that the stress concentration increases, cracks α occur in the weld (b), and the fatigue life of the weld becomes short.

The present invention has been made in view of the above circumstances, and its purpose is to provide a single-sided welding method that reduces stress concentration at crack initiation points and improves fatigue life.

Embodiment 'A' of the present invention will be described below with reference to FIG. 3 and subsequent figures.

As shown in FIG. 3, a non-welding plate, such as a cutter plate 12, is butted against the position on the side surface 1oα of the 3111 member 1o where the second member 11 is to be welded. 12 and the first member 10 are fillet welded to form a shelf 13.

As shown in FIG. 4, the nail 12 is struck and removed from the first member 10, leaving a shelf 13 corresponding to a conventional nail plate on the first member 10.

The shelf portion 13 has a smooth surface and a contact surface 13α of the second member 11.
The curved surface +36 forms a substantially triangular protrusion, which corresponds to a conventional back plate.

As shown in FIG.
A space 14 surrounded by the end face 11α of the second member 11 is welded to form a welded portion 15.

By welding in the manner described above, the stress concentration at the crack origin is reduced, and even if a large load is applied, the crack α will not form early in the welded part 15, and the fatigue life of the welded part will be improved. do.

As shown in FIG. 6, one end of the second member 11 is tapered and curved to abut against the contact surface 13α of the shelf 13,
It may be fixed by welding.

Next, the box-shaped hollow object 20 shown in FIG. 7 is manufactured by the conventional welding method shown in FIG. 1 and the welding method according to the present invention shown in FIGS. FIG. 9 shows the results of a oscillating fatigue test in which the specimen was supported at both ends as shown in FIG. 8 and a load F was repeatedly applied to the center.

This result also shows that fatigue life is improved when welding is performed by the welding method according to the present invention shown in FIGS. 3 to 5.

In FIG. 9, white circles indicate welding according to the present invention and black circles indicate welding according to the conventional welding method.

The thickness of each of the first members 1, 1o and the m22 member 11 was 12 mm, the width of the space 4.14 was 7 mm, and the length of the back plate 2 was 12 mm.

According to the single-sided welding method according to the present invention, the stress concentration at the crack starting point is reduced, making it difficult for cracks to form in the welded portion, thereby improving the fatigue life.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of different conventional examples, and Figure 3 is an explanatory diagram of different conventional examples.
Figures 4 and 5 are process order explanatory diagrams showing one embodiment of the present invention, and Figure 6 is an illustration of another %lJi! i9!1 explanatory diagram,
FIG. 7 is a front view of the box-shaped hollow part, FIG. 8 is an explanatory diagram of the test method, and FIG. 9 is a diagram showing the test results. IO is the first member, 11 is the second member, 12 is the backing plate, 13
is a shelf, and 14 is a space. Applicant Komatsu Ltd. Nippon Steel Corporation Representative Patent Attorney Masaaki Yonehara Tadashi Hamamoto Figure 1 Figure 2 Figure 7 Figure 1.10 Figure 23 IF

Claims (1)

[Claims] A shelf is formed on the first member by fillet welding using a non-welding caul plate, a second member is brought into contact with the shelf to form a space, and this space is welded to form a shelf. 1. A single-sided welding method characterized by fixing the second member by welding.