JPH10296480A - Pressurizing method and pressurizing device for weld toe - Google Patents

Abstract

(57) [Summary] [Problem] A method and a device for pressurizing a weld toe portion that can be easily constructed on site without generating dust or noise and without having to transport a large work. To be provided at low cost. A rotating body held at a tip of a rotating body holder.
2 is pressed through the holder 11 in a state where the holder 2 is in contact with the weld toe 4 of the work, and the holder 11 or the work is moved along the welding portion to press the weld toe 4. A pressurizing method of an end portion, a rotating body holder 11 holding a rotating body 12 at a tip, a support 13 of the holder 11, and a pressurizing force transmitting a pressing force to the rotating body 12 via the rotating body holder 11. It is composed of a pressurizing device for the weld toe, which is composed of the mechanism 14 and does not generate dust or noise. Therefore, the working environment is not deteriorated. It is not necessary to transport the work, the work can be easily carried out on the spot, and the apparatus is simple, so that it can be provided at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressurizing method for increasing the fatigue strength of a weld toe, and a pressurizing apparatus used for the pressurizing method.

For example, when performing arc welding, it is well known that measures are taken to improve the fatigue strength of the weld toe for the purpose of reducing stress concentration at the welded portion and adding compressive residual stress. This strategy has been
Grinder processing, remelting (reheating) processing, shot blast processing, shot peening processing, and the like are common.

[0003]

However, these processing means not only generate dust and noise, deteriorating the working environment, but also often require transporting the work after welding to the installation location of the equipment. There is a possibility that work efficiency will be reduced.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, does not generate dust and noise, and does not need to transport a large work. It is an object to provide a method and a pressurizing device at low cost.

[0005]

According to the present invention, there is provided a method for pressurizing a welding toe portion, wherein a rotating body held at a tip of a rotating body holder is brought into contact with a welding toe portion of a work. In this state, it is pressed through the holder, the holder or the workpiece is moved along the welded portion to press the weld toe, and the pressurizing device for the weld toe according to the present invention has It is characterized by comprising a rotator holder holding a rotator, a holder for the holder, and a pressure mechanism for transmitting a pressing force to the rotator via the rotator holder.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method and apparatus for pressurizing a weld toe according to the present invention will be described in detail with reference to FIGS. The method for pressurizing the weld toe of the present invention is basically, for example, as shown in FIG.
a, at the toe 4 of the welded portion 3 where arc welding is performed between 2a,
In a state where the rotating body 12 held at the tip of the holder 11 is brought into contact with the rotating body 12, the rotating body 12 is pressed through the holder 11, and the holder 11 or the workpieces 1 and 2 are moved along the longitudinal direction of the welding portion 3 to weld toe. The part 4 is pressurized.

As shown in FIGS. 2 and 3, the pressurizing device of the present invention comprises a rotating body holder 11 holding a ball 12 which is a rotating body at a tip end thereof, a support 13 for the holder 11, and a pressurizing device. And a mechanism 14. The rotator holder 11 has a flange 15a at one end, a circular hole 15c formed in a base end 15 having a screw portion 15b formed on the outer periphery, and a distal end portion 16 holding a ball 12 at the distal end. Of the piston 16a and the stopper 15d provided at the outlet of the circular hole 15c.
It is interposed between.

As shown in FIG. 2, for example, the supporting member 13 is formed by welding members 18 and 19 having high rigidity in a frame shape and welding holes 18a and 18b in the center of the members 18. I have. The pressurizing mechanism 14 is, in this example, FIG.
As shown in FIG. 3, a communication path 15e is formed at the center of the base end portion 15 of the rotating body holder 11 so as to communicate from the collar 15a to the circular hole 15c.
A joint 20 communicating with 5e is screwed, one end of a pipe 21 is connected to the joint 20, and the other end is connected to a pressure source (not shown), for example, a hydraulic pump.

The rotating body holder 11 has a threaded portion 1 with the collar 15a of the base end portion 15 placed inside the support 13.
5b is inserted into the hole 18a of the member 18, and the nut 22 is screwed to the screw portion 15b and attached to the support 13. Then, the other end of the pipe 21 is brought out of the support 13 through a hole 18b formed in the other member 18, and is connected to a pressure source. In addition, a disk-shaped roller may be used instead of the ball 12, and in this case, the surface of the roller is preferably formed in a drum shape according to the shape near the weld toe 4. In the illustrated example, the pressurizing mechanism 14 intends to use hydraulic pressure or pneumatic pressure. However, if a pressing force can be transmitted to the rotating body 12 via the rotating body holder 11, for example, a strong spring force is applied. May be used.

When the method for pressurizing the weld toe of the present invention by the pressurizing device is carried out, the support 13 is fixed to the vicinity of the welded portion 3 by a suitable jig (not shown). As shown in FIG. 1, the toe 4 of the welded portion 3 of the workpieces 1 and 2
In a state where the ball 12 held at the tip of the holder 11 is brought into contact with, for example, a hydraulic pressure is applied from the pressurizing source to the communication path 15 e in the holder 11 via the pipe 21 and the joint 20, the rotating body holder 11 and 12 moves to the left in FIGS. 2 and 3 against the spring 17 and presses the toe 4 through the ball 12, thereby improving the fatigue strength of the weld toe. Therefore, in this state, the workpieces 1 and 2 may be moved along the longitudinal direction of the welding portion 3 to press the welding toe 4. Of course, the support 13 is not fixed, but is movably supported on the rail in the vicinity of the welded portion 3,
The pressurizing device of the present invention may move the works 1 and 2 along the longitudinal direction of the welded portion 3.

[0011]

According to the method of pressurizing the weld toe portion of the present invention, the rotating body held at the tip of the rotary body holder is pressed through the holder while being in contact with the weld toe portion of the work. The holder or the workpiece is moved along the welded portion to press the weld toe, and the pressurizing device for the weld toe includes a rotating body holder holding a rotating body at a tip, It is characterized by comprising a holder support and a pressurizing mechanism for transmitting a pressing force to the rotating body via the rotating body holder, so that no dust or noise is generated, and thus the working environment is deteriorated. And it can be easily installed near the welded part of the work, so there is no need to transport a large work.
Since it can be easily constructed on the spot and the apparatus is simple, there is an effect that a method and apparatus for pressing the weld toe can be provided at low cost.

The results of a plane bending fatigue test (stress ratio = -1) performed by the applicant using a steel plate test piece 32 having a weld 31 at the center as shown in FIG. 4 are shown below. In this case, as shown in FIG.
The angle .alpha. Formed by the center axis of the rotating body holder with respect to the surface of the rotating body 2 is 60 degrees, the radius r of the rotating body (ball) and the welding portion 3
Assuming that 1 is a semicircle, the ratio r / d to the radius d is 0.5 to
The pressure was set to 0.8 after the welded portion 31 was sufficiently cooled. The processing load (pressing force) at this time was 9800 N (Newton) or less, and the feed speed of the test piece 32 was a constant speed of 450 mm / min. FIG. 6 shows the results obtained by performing the pressurizing method of the present invention under the above conditions. The horizontal axis indicates the processing load, and the vertical axis indicates the improvement rate of the fatigue life. 3 shows the ratio of the fatigue life of the weld toe of the test piece to which the pressurizing method of the present invention was applied to the fatigue life of the weld toe of the test piece. As shown in FIG. 6, as the processing load increases, the fatigue life improvement rate increases remarkably. For example, at the processing load of 9800 N, the fatigue life is reduced by the fatigue of the weld toe of the test piece which was not subjected to the pressing method of the present invention. It was found that the service life reached more than five times. In addition,
Σa in FIG. 6 indicates the amplitude of the nominal bending stress obtained by dividing the bending moment applied to the weld toe by the section modulus of the same.

[Brief description of the drawings]

FIG. 1 is a basic conceptual diagram of a method for pressurizing a weld toe according to the present invention.

FIG. 2 is a cross-sectional view of a pressurizing device used in the pressurizing method of the weld toe according to the present invention.

FIG. 3 is an enlarged sectional view of a main part of FIG. 2;

FIG. 4 is a plan view of a test piece used for confirming the effect of the method of pressurizing the weld toe according to the present invention.

5 is a schematic side view showing a positional relationship between a toe portion of a welded portion of the test piece shown in FIG. 4 and a rotating body holder.

FIG. 6 is a view showing a test result by the pressurizing method of the present invention using the test piece shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 2 Work 3 Welding part 4 (Welding) toe end 11 Rotating body holder 12 Ball (rotating body) 13 Supporting device 14 Pressure mechanism 15 Base end (of rotating body holder) 16 Tip end (of rotating body holder) 17 Spring 18, 19 (of support) 20 Joint 21 Pipe 22 Nut.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Keisuke Toyama 2003-1 Endo, Fujisawa-shi, Kanagawa 1 Press Industry Co., Ltd.

Claims (4)

[Claims] A rotating body held at the tip of a rotating body holder is pressed through the holder in a state in which the rotating body is brought into contact with a welding toe of a work, and the holder or the work is moved along a welding portion. A method for pressurizing a weld toe, comprising pressurizing the weld toe. 2. A rotator holder holding a rotator at a tip thereof;
A pressurizing device for a weld toe, comprising: a support for the holder; and a pressurizing mechanism for transmitting a pressing force to the rotating body via the rotating body holder. 3. The apparatus according to claim 2, wherein said rotating body is spherical. 4. The pressurizing device for a weld toe portion according to claim 2, wherein said rotating body has a disk shape.