JPS6127172A - Shielded welding equipment by inert gas of small diameter pipe - Google Patents

Abstract

PURPOSE:To cut off all parts of welding from air, and to execute a good inert gas arc welding by providing a gas lens in a frame for covering the periphery of a small diameter pipe, providing a diffusing pipe, and providing separately an opening part for inserting the tip of a welding machine, and a window on the gas lens and the frame. CONSTITUTION:A shielded welding equipment is formed so that an upper frame 1 and a lower frame 2 can be opened and closed by a shaft 3. Subsequently, a plate 5 having a welding window 4 and a windproof plate 6 are installed to the upper part of the upper frame 1. Also, semicircular bearing parts 17, 17' of a pipe of the maximum diameter are provided on the upper and the lower frames 1, 2, and grooves 13, 13' are worked on the cylindrical wall of the bearing part. Moreover, the same groove is worked on faying parts, too, of the upper and the lower frames 1, 2, and packing is fitted in. Subsequently, the inside of the upper and the lower frames is packed with steel wool made of stainless steel. A gas lens 16 is formed by pressing down the upper part of said steel wool by a wire mesh, diffusing pipes 19, 19' are povided on the inside, and an argon gas is supplied into the equipment from fitting pipes 8, 15. Also, with respect to a difference of the pipe diameter, a jig is prepared and used for welding of many kinds of pipes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention was invented for the purpose of improving the shielding performance of an inert gas such as argon gas during welding when welding titanium or other welding that requires shielding. This invention relates to a shield welding device for manual welding of relatively small diameter pipes with an outer diameter of 89.1 wm (3 inches) or less using an inert gas.

In particular, here we will focus on welding titanium.

Titanium has a strong affinity with other elements at high temperatures, and when it reacts with them, corrosion resistance deteriorates and corrosion occurs. Therefore, sufficient shielding with argon gas is required during welding, and in order to achieve this completely, it is common to weld both the front and back surfaces of the weld bead with argon gas replaced with air.

Titanium materials are generally used in reaction towers, distillation towers, and condensers of seawater desalination equipment in the petrochemical industry, fertilizer industry, and industrial industries.

When titanium is exposed to high temperatures during welding, its surface turns sequentially silver, gold, blue, purple, etc. depending on the shielding condition at that time.
Changes to grayish white. During welding, a weld that turns silver, gold, blue, or purple is considered to be a sound weld and has little effect on mechanical properties or corrosion resistance.

However, in reality, it is difficult to meet the above purple conditions because there is currently no complete shielding device using argon gas.

If it is an experimental device, it can be done indoors or in a factory under good conditions, but the conditions at the site are quite difficult due to wind and foot traffic. Particularly in the vicinity of 40 to 50 screens from the center of the welding electrode (torch), turbulent flow occurs due to heat during welding, causing air to be entrained. In the case of titanium welding, good welding is possible if the air entrainment is 4 to 5% or less, depending on the oxygen content, but if only oxygen is considered, it is 1% or less.

The device according to the invention has been invented especially for use in the welding of small diameter pipes, also in the welding of pipes. When welding small-diameter pipes, the heat affects the entire circumference of the pipe, so even if some parts of the pipe are completely shielded, air may be mixed in on other circumferences, and the temperature may exceed 550°C. If the heat effect is as described above, a bad result such as purple or grayish white color is inevitable, depending on the amount of air mixed in. For this reason, the filling structure of the gas lens (G) according to the present invention is a structure that completely prevents air entrainment by filling the base material tube so as to cover the entire circumference, as shown in Figure 2. I'll go. It was specifically invented for use in manual welding of small diameter pipes of 89.1 m (3 inches) or less. In the case of pipes of 89.1so or less, thermal effects become a problem as described above, but this problem could be solved by the shield welding apparatus according to the present invention.

In this invention, a gas lens is provided within a frame that covers the periphery of a welded portion of a relatively small diameter pipe, a diffuser pipe for supplying inert gas is disposed in this, and the tip of a welding machine is attached between the gas lens and the frame. This is a shield welding device using an insoluble gas for small diameter pipes, each of which has a separate opening for insertion and a welding window.

In this invention, in order to fit the pipe to be welded, the frame is divided into an upper frame and a lower frame, each of which is provided with a gas lens, and a semicircular bearing for fitting with the maximum diameter pipe to be welded. In the welding device, a U-shaped packing groove is formed in the cylindrical wall of the upper frame and the lower frame.

The present invention is the welding device in which a jig for small diameter pipes is further fitted to the packing hole.

The present invention is the welding device, wherein the dimensions of the welding window are 28 to 30 in width and 47 to 62 in length.

The dimensions of the welded window (4) are the results of experiments and are the best dimensions for preventing inert gas from leaking through the window (4) and for wind protection. Although it depends on the amount of inert gas supplied, the windproof effect is best regardless of the amount supplied. Even if the device becomes larger, the dimensions of this window remain within the above dimensions. In particular, the welding window dimensions allow for good welding even without the use of a windproof or leak-proof cover.

The structure of the device of the present invention is that the upper frame (1) and the lower frame (2) are
) (3) is hinged so that it can be opened and closed. A plate (5) having a welded window (4) and a windbreak plate (6) are attached to the upper part of the upper frame (1) in the front and back.

The upper frame (1) and the lower frame (2) are machined with semicircular bearing parts α and σ6, respectively, for pipes with the maximum diameter that the device can handle, and the cylindrical wall of the bearing parts has a cross-sectional shape. U-shaped grooves a and - are respectively machined. As shown in Fig. 3, similar grooves are machined on the left and right sides of the lower frame (2) at the part where the upper frame (1) and the lower frame (2) meet, and the grooves α3 and
(A gasket (i5.64) with a circular cross section as shown in Fig. 5 is fitted into the IL (to).A gasket (i5.64) with a circular cross section as shown in Figure 5 is fitted into the groove (2) and (1) of the upper frame (1). A similar semicircular gasket is fitted. Figure 3 shows the upper frame (1) opened. The gas lens (end) is stuffed with stainless steel wool inside the upper and lower frames, and It is formed by holding it down with stainless steel wire. Inside, an argon gas diffuser pipe a4 is arranged as shown in Fig. 4. The mounting pipe (8) and αQ are each made of vinyl. tube(
(e) is connected so that argon gas is supplied into the device from here.

The gas lenses (G) are pressed by presser rods 04 in the upper and lower blocks, respectively.

Next, for attachment to the pipe during welding, the upper frame (1) is opened and attached to the tack-welded pipe as shown in Figure 3. Fit the lever (9) into the lever groove (B) and tighten the screw (G) to secure it. When welding, start by installing an argon gas tube as shown in Figure 10 and expelling the air inside the tube with argon gas. Argon gas is heavier than air, so an effective method is to tilt the tube somewhat, supply argon gas from the bottom of the tube, and install a valve at the top to expel the air from there. At the same time, argon gas is also supplied to the welding equipment.

Figure 10 shows the state in which the welding device according to the present invention is used. In this case, the pipe is fixed and the welding device is rotated little by little by the weight of the arm while welding. In Fig. 11, the end of the tube is attached to a stand (1) that rotates the tube at a constant speed, and the other end is placed on top of two rollers (01), and the device is held horizontally by the weight of the arms. Welding can also be carried out while holding.

Next, in the device of the present invention, α6 of the bearing portion α for the maximum diameter
If you are trying to weld a pipe with a smaller outer diameter, a jig like the one shown in Figures 6 to 9 is available. Although not shown in Figures 3 to 3, remove the gasket i shown in Figure 5 that is fitted into the stable, fit the aforementioned jig Q]), and use the hole (E) to tighten the bolt @ Attach them to the internal screw holes (c) respectively. A packing having the same shape as the packing d in Fig. 5 may be installed in the packing groove (+3), 'Q;) in Fig. 6. As mentioned above, a single device can be used for pipes of various sizes by replacing the jig, making it a convenient and economical device.

Symbols (25)' and (2g) are fitting projections and depressions.

In the shield welding device using inert gas according to this invention-
In this method, the entire part of the small diameter pipe welded is always shielded from the air by inert gas, so it is possible to perform good inert gas arc welding.

Easy to attach and detach from the pipe to be welded and welding operations. By preparing a jig for different pipe diameters, it can be used for welding pipes for multiple foods. Good welding even in windy outside air.

can be done.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a welding device according to the present invention. Figures 2 and 6 are perspective views of the inside of the welding device shown in Figure 1, Figure 4 is a perspective view of the air diffuser, Figure 5 is a perspective view of the packing, and Figure A6 is a front view of the jig. , FIG. 7 is a side view thereof, part 8
9 is a front view of the jig, FIG. 9 is a side view thereof, FIG. 10 is a perspective view showing welding work, and FIG. 11 is a perspective view showing another welding machine. In the drawing, code (1) is the upper frame, (2) is the lower frame, (3) is the shaft, (4) is the welding window, (5) is the plate, (6) is the windbreak plate, (8), (i) ) is the mounting pipe, (9) is the lever, (
G) is a screw, (2) is a lever groove, Q3. Q3, (g)
is the groove, CL wire is for cutting, Q4 is the presser bar, (to) is the gas lens, α force, α6 is the bearing for the maximum diameter, target, α4 is the diffuser pipe, the handle is the vinyl chishive, and the deer is the jig. , Ren is a bolt, i is a hole, (goods) is a screw hole, 咎, - is a recess for fitting, 弼 is a pipe, 翰 is ・(rupu, ni) is a stand, eat-t,, t=-
It is ra.

Claims (1)

[Claims] 1. A gas lens is provided within a frame that covers the periphery of a welded portion of a relatively small diameter pipe, a diffuser pipe for supplying inert gas is disposed in this, and the gas lens and frame are connected to each other. A shield welding device using insoluble gas for small diameter pipes, each having a separate opening for inserting the tip of a welding machine and a welding window. 2. The frame is divided into an upper frame and a lower frame, each of which is provided with a gas lens, in order to fit the pipe to be welded, and a semicircular bearing part to fit the maximum diameter pipe to be welded. is formed at the joint portion of the upper frame and the lower frame, and a U-shaped packing groove is formed in the cylindrical wall of these. . 3. The apparatus for shield welding small diameter pipes using an inert gas according to claim 2, wherein a jig for small diameter pipes is further fitted into the packing groove. 4. The dimensions of the welding window are 28 to 30 mm in width and 47 mm in length.
A shield welding apparatus using an inert gas for small diameter pipes according to claims 1 to 3, wherein the diameter is 62 mm.