JPS6056593B2 - Single side welding method - Google Patents

Description

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

Conventionally, as shown in FIG. 1, this type of single-sided welding method involves temporarily welding a back plate 2 to the side surface 1a of a first member 1, bringing the second member 3 into contact with the back plate 2, and then , a space 4 surrounded by the side surface 1a of the first member 1, the back plate 2, and the end surface 3a of the second member 3 is welded from one side to fix the first member 1 and the second member 3. welding method.

As shown in FIG. 2, a method is known in which the back plate 2 is butt-welded without tack welding.

Back plate 2 for sumo wrestlers, regardless of the welding method.
has a rectangular cross section, so when a load is applied, the stress at the crack starting point A (the contact area between the horizontal member 3 and the back plate 2, the area between the contact between the back plate 2 and the side surface 1a of the first member 1) The problem is that the concentration becomes large and a crack a is generated at the mouth of the weld, resulting in a shortened fatigue life of the weld.

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 the crack origin and improves fatigue life. Embodiments of the present invention will be described below with reference to FIG. 3 and subsequent figures.

As shown in FIG. 3, a non-welding patch plate, for example, a copperback 12, is butted against the side surface 10a of the first member 10 at a position where the second member 11 is to be welded, and the copperback 12 and the first member are welded together. A shelf 13 is formed by fillet welding the corner with 10. As shown in FIG. 4, the copperback 12 is struck and removed from the first member 10, leaving a shelf 13 in the first member 10, which corresponds to a conventional pack plate.

The shelf portion 13 has a smooth contact surface 13a of the second member 11.
．． (The five-curved surface 13b forms a substantially triangular protrusion,
It corresponds to a conventional back plate.

As shown in FIG. 5, the second member 11 is brought into contact with the contact surface 13a of the shelf 13, and the side surface 10a of the first member 10
A space 14 surrounded by the end face 11a of the second member 11 is welded to form a welded portion 15.

By welding as described above, the stress concentration at the crack starting point A is reduced, and even if a large load is applied, a crack a does not occur early in the welded part 15, and the fatigue life of the welded part is improved.

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

Next, a box-shaped hollow object 20 shown in FIG. 17 is manufactured by the conventional welding method shown in FIG. 1 and the welding method according to the present invention shown in FIGS. 3 to 5. FIG. 9 shows the results of a oscillating fatigue test in which the hollow object 20 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 are those obtained by the welding method according to the present invention, and black circles are those obtained by the conventional welding method.

The thickness of the first members 1, 10 and the second members 3, 11 was 12 wft, the width of the spaces 4, 14 was 7 wIn, and the length of the back plate 2 was 12 Tn.

According to the single-sided welding method according to the present invention, the application concentration of crack starting points is reduced, making it difficult for cracks to occur in the welded part, and improving fatigue life.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams of different conventional examples, and Figure 3 is an explanatory diagram of different conventional examples.
4 and 5 are process order explanatory diagrams showing one embodiment of the present invention, FIG. 6 is an explanatory diagram of another embodiment, FIG. 7 is a front view of the box-shaped hollow part, and FIG. 8 is an explanatory diagram of the test method, and FIG. 9 is a diagram showing the test results. 10 is a first member, 11 is a second member, 12 is a backing plate, 13
is a shelf, and 14 is a space.

Claims (1)

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