JPS5838274B2 - Wet underwater welding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wet underwater welding apparatus using a welding heat source that spouts gas.

More specifically, the present invention relates to a wet underwater welding device that allows welding while checking the welding location, is simple, and provides a good welding effect.

The application of underwater welding to the construction and repair of underwater structures, especially wet underwater welding in which welding is performed directly underwater, is easy to perform and inexpensive, contributing to the development of underwater structures. It's a big deal.

However, this method is still not fully utilized.

The reason for this is that, firstly, in order to obtain a sound welded joint during wet underwater welding, it is essential to protect the welding area from surrounding water in a stable state, but it is essential to exclude water from the welding area. Insufficient technology.

Second, there are concerns about the quality of the joints obtained by this welding method.

That is, it is very difficult to prevent water and hydrogen from entering the arc and the welding area due to the presence of water or water vapor around the welding area, and in addition to this, due to the quenching effect of the presence of water. In welded parts, material deterioration such as micro-cracking and the resulting decrease in ductility is a problem.

In particular, these problems become even more important when welding in vertical or horizontal positions.

Conventionally, as a measure to solve this problem, in welding using shielding gas such as TIG welding and MIG welding, in addition to the original shielding gas, a method of flowing a protective gas to further protect the welding point, a method of flowing a casing, etc. Attempts have been made to apply waterproofing technology using fluids, such as creating a fluid wall underwater with jet water and supplying shielding gas or protective gas to the inside of the wall.

However, in the former case, when the shielding gas or protective gas floats up from the welding point, a large volume of it floats up.
The pressure equilibrium between the gas cavity and the surrounding water is disrupted, and water frequently enters the welding area, making it impossible to maintain the stability of the bead.

Further, as the shielding gas becomes vertical, the arc is disturbed due to the floating of the shielding gas, and the shielding gas no longer plays its role.

The latter has had some success in the downward position.

However, even with this successful method, there is a tendency for water to enter the welding area from below as the weld is placed in an upright position.

Furthermore, by using MIG welding, adjacent members are arranged in a fluid-tight manner around the entire outer circumference of the support guide cylinder of the weld core, a curtain-like partition wall is provided for waterproofing, and a jet nozzle is provided on the outside of the curtain-like partition wall for waterproofing. Attempts have also been made to suck the gas present at the welding point into fine bubbles.

(Japanese Patent Publication No. 53-34570) In each of the above methods, an additional fluid is supplied in addition to the original shielding gas for welding, which increases the size of the device and increases the cost of the housing, especially for the latter two. In addition, it is difficult to directly visually confirm the welding location because of the presence of small suction bubbles or curtain-like partition walls around the entire circumference.

On the other hand, attempts have been made to apply oil putty on both sides of the weld line to reduce the hardening of the weld heat-affected zone by using a coated rod, but this method does not cover the entire length of the weld line. It has not been put into practical use because it requires waterproofing measures.

The present invention aims to eliminate the above-mentioned drawbacks of conventional devices and provides a wet underwater welding device that is simple, easy to handle, and capable of welding while observing the welding location.

The apparatus of the present invention will be explained based on the drawings. FIG. 1 is a side sectional view of the apparatus showing one embodiment of the apparatus of the present invention, and FIG. 2 is a front view thereof.

1 and 3 are overhead views showing another embodiment, and FIG. 4 is a side sectional view of the device when it is incorporated into a welding torch.

In Figures 1 and 2, 1 is a solid sliding wall, 2 is a gas outflow slit provided in the solid sliding wall 1 located in the gas upward direction, and 3 is the tip of the solid sliding wall 1 connected to the base plate. 5 is a welding torch, 6 is a gas ejected from a welding heat source, 7 is a solid sliding wall and a housing for housing the pressure spring 3, 8 is a screw; It is a public waterway.

In this device, a spring is used to slide the solid sliding wall, but the present invention is not limited to this, and other pressing means such as rubber, pneumatic pressure, hydraulic pressure, etc. may be used.

The solid sliding wall 1 is provided at the tip of the welding torch 4, and only on the top and bottom, not on the sides, and is in an open state.

The material of the solid sliding wall 1 is preferably one that can withstand the temperature rise K due to radiation from the welding heat source, is resistant to thermal shock, and has high thermal insulation properties.

To perform welding using this device, the welding torch 4 is held so that the solid sliding wall 1 is at a position perpendicular to the direction in which gas ejected from the welding heat source floats in various welding positions.

The pressure of the spring 3 presses the solid sliding wall 1 so that it always maintains contact with the surface of the base plate 5.

After that, when the gas is ejected, the rising of the gas is suppressed by the solid sliding wall installed above, and the gas dissipates to the side opening, and then the solid sliding wall installed below allows the gas to be released from below. prevent water from entering.

That is, both solid sliding walls suppress gas dissipation from above and prevent water from entering the welding area, thereby forming a gas cavity at the welding area.

Therefore, there is no need for complicated additional installation of a gas cavity formation/maintenance barrier, and the apparatus becomes simple.

The sides are open, so check the welding position and start welding.

As welding progresses, this device is moved by sliding on the base plate 5 to perform welding.

Note that the gas outflow slit 2 does not necessarily need to be provided, and the ejected gas can escape from the side opening, thereby preventing water from entering.

3 and 4 show a case where the solid sliding wall 1 is built into the tip of the welding torch 4. FIG.

The other parts are the same as those shown in FIG. 1, and welding can be performed in the same manner using the other equipment.

Note that, as shown in FIG. 3, the solid sliding wall can be divided to facilitate passing through the bulge formed by welding.

The shape of the tip of the twisted solid sliding wall 1 on the side in contact with the base plate 5 is as follows:
It can have a shape corresponding to the shape of the mother plate, such as a groove shape or a fillet shape.

According to the wet underwater welding apparatus of the present invention, the following excellent effects can be obtained.

■) Conventionally, in wet underwater welding, complicated equipment and operations were required to prevent water from entering the welding area, but the present invention eliminates these problems by using extremely simple equipment. Solvable.

2) With conventional waterproofing technology using fluid, it was difficult to perform good welding in vertical positions, but according to the present invention, welding can be performed in any position.

3) The arc length setting range can be widened.

4) As shown in the examples, the cooling of the welded part can be relaxed, and the stress on the hardened part is reduced.

5) Since no complicated equipment or operations are required for waterproofing, it can be carried out at almost the same cost as conventional welding in the atmosphere, and no special expenses are required.

6) Since the tip of the welding torch is not entirely covered by a solid sliding wall and the side surfaces are open, the welding location and welding condition can be easily confirmed from the open part, allowing excellent welding to be performed.

Example 1 The base plate is made of JIS-SM4 1A steel and has a thickness of 12 mm, a width of 200 mm, and a length of 200 mm.

For welding, plasma arc welding was used using the apparatus shown in FIG.

The welding conditions at that time were a current of 125 A and a voltage of 75 V.
, feeding gas flow rate 2-5 l/min, torch base plate spacing 6
mm, the water temperature was 24°C, the water depth was 100m, and the base plate had a rotation angle of 45° and an inclination angle of 0°.

The results obtained were caterpillar-like beads when this device was not used, but good beads were obtained when this device was used.

In fact, the maximum hardness of the heat-affected zone without using this device was 460 Vickers hardness, but with the use of this device, it became 360.

Example 2 Welding was carried out under the same conditions as in Example 1, except that the current was IOOA and the rotation angle of the base plate was 90 degrees.

As a result, when this device was not used, no bead was formed, but when this device was used, a fairly good bead was obtained, and the maximum hardness of the heat-affected zone was 390 Vickers hardness.

[Brief explanation of drawings]

The drawings show an embodiment of the wet underwater welding apparatus of the present invention; FIG. 1 is a side sectional view, FIG. 2 is a front view thereof, FIG. 3 is an overhead view of another embodiment, and FIG. FIG. 3 is a side sectional view of the device when incorporated into a welding torch. 1... Solid sliding wall, 2... Gas outflow slit, 3... Pressure spring, 4... Welding torch, 5...・Mother plate, 6...Blowout gas, 7...Using, 8...Screw,
9... Waterway.

Claims (1)

[Claims] 1. In a wet underwater welding device using a welding heat source that ejects gas, a solid sliding wall is installed at the tip of the welding torch so that the tip can slide so that the tip comes into contact with the base plate using a pressurizing mechanism.
The part that separates the welding torch is built into the welding torch,
A wet underwater welding device characterized in that the welding torch is provided oppositely at the upper and lower portions in the upward direction of gas, and the other tip portion of the welding torch provided with the solid sliding wall is open.