Gas protection device for back of fillet weld of connecting pipe

Abstract

The invention discloses a gas protection device for the back of a fillet weld of a connecting pipe. The gas protection device comprises a gas circulation device, a weld joint matching mechanism, a clamping ring, a gas dispersion device, a fixing ring and a gas backflow regulator. The welding seam matching mechanism is installed on the gas circulation device, the clamping ring is installed in an annular groove in the welding seam matching mechanism and can be clamped and fixed to the inner wall of a main body workpiece, the gas dispersion device is installed at a gas outlet in the welding seam matching mechanism and fixed through a fixing ring, and the gas backflow regulator is installed at the tail of the gas circulation device. And gas outflow can be controlled by adjusting the position through the threads. The device is suitable for a pipe fillet weld structure needing full penetration welding, protective gas can evenly flow through the back face of the weld to form a stable and continuous atmosphere, and therefore good weld quality is obtained, the use amount of the protective gas can be effectively reduced, the manufacturing cost is reduced, and the production efficiency is improved. In addition, operation is simple, and the modular design has high universality.

Description

Technical Field

[0001] The invention relates to the technical field of welding, in particular to a gas protection device for the back of a pipe fillet weld. Background Art

[0002] Fillet weld is one of the widely used welding joint forms, which is widely used in boilers, pressure vessels and other products. It involves a variety of non-alloy steel, alloy steel, stainless steel and other materials. For some special materials, such as 91 and stainless steel, in order to obtain better weld quality and weld formation during the welding process, it is necessary to use shielding gas to protect the back of the weld. For example, in the welding process of full penetration fillet weld structure, single-sided welding and double-sided forming are required. In order to obtain qualified quality and excellent forming welds, higher requirements are placed on the gas protection environment on the back of the weld, especially when using tungsten inert gas shielded welding method.

[0003] In addition, due to the structural characteristics of the corner weld of the pipe, it is difficult to construct a good and stable protective atmosphere on the back of the weld in actual production. In some specific cases, it is necessary to seal the entire workpiece and introduce inert gas to fill the entire workpiece, leaving only an opening at the position to be welded to achieve the effect of inert gas protection. However, the protection effect of this method is limited, the consumption of protective gas is large, and the gas use cost is high. Summary of the invention

[0004] In order to solve the above technical problems, the present invention designs a gas protection device for the back of a pipe fillet weld.

[0005] The present invention adopts the following technical solution: A gas protection device for the back of a pipe fillet weld is used for a pipe fillet weld structure. The pipe fillet weld structure includes a pipe and a main workpiece. An assembly gap is left between the pipe and the main workpiece. The protection device includes a gas circulation device, a weld matching mechanism, a clamping ring, a gas dispersion device, a fixing ring, a gas reflux regulator and a gas pipe. The weld matching mechanism is installed on the gas circulation device. The clamping ring is installed in an annular groove on the weld matching mechanism and can be clamped and fixed with the inner wall of the main workpiece. The gas dispersion device is installed at the gas outlet on the weld matching mechanism and fixed by a fixing ring. The gas reflux regulator is installed at the tail of the gas circulation device and can control the outflow of gas by adjusting the position of the thread. The protective gas enters the device from the gas inlet of the gas circulation device through the gas pipe, and escapes from the position of the gas dispersion device through the gas circulation device and the weld matching mechanism, forming a relatively uniform protective atmosphere on the back of the pipe weld. A part of the protective gas escapes from the gap between the pipe and the main workpiece, and the other part continues to flow into the pipe and finally flows out from the gas reflux regulator through the reflux pipe in the center of the gas circulation device.

[0006] Preferably, the gas circulation device is a multi-chamber tubular metal structure, including an air inlet pipe, a shell, an air guide pipe, a central pipe, an end plug, and a tail threaded plug. The shell is fixed to the air guide pipe to form a first air chamber, the air guide pipe is fixed to the end plug and the central pipe to form a second air chamber, the air inlet pipe is connected to the shell and communicated with the first air chamber, and the air inlet pipe communicates with the air pipe. A better solution is to use stainless steel.

[0007] Preferably, the outer edge of the inner end of the shell is provided with a thread, and the end of the thread is provided with a limiting step higher than the thread.

[0008] Preferably, the air guide tube is a tubular porous structure, connected to the central tube, the outer shell, and the end plug by welding, and multiple rows of openings are evenly distributed around the air guide tube. The preferred solution is a waist-shaped hole.

[0009] Preferably, the end plug is cylindrical, the outer diameter of which matches the inner diameter of the air guide tube and is connected by welding, one end of which is provided with a thread, and the center is provided with a through hole, the inner diameter of which matches the outer diameter of the center tube and is connected by welding.

[0010] Preferably, the central tube is a straight tube fixed to the shell, the air guide tube, and the end plug by welding, one end of which is open, and the other end is fixed to the tail thread plug by welding, and openings are arranged around the position of the tail thread plug, and the tail thread plug is threadedly connected to the gas reflux regulator, which is a hollow structure, one end of which is provided with threads and matched with the tail thread plug, and the inner diameter of the other end is matched with the outer diameter of the central tube. The preferred solution of the gas reflux regulator is to have a smooth surface and a length that can cover the opening of the central tube, and the outer shape is cylindrical and the outer surface is arranged with twill to increase friction.

[0011] Preferably, the weld fitting mechanism is a multi-layered step metal cup-shaped structure, which can be configured in various specifications according to the actual size of the workpiece, with a cover at one end and a threaded hole in the center, the thread is matched with the end plug, the interior is hollow and the inner wall has threads, the threads are matched with the shell, and the weld fitting mechanism is assembled with the gas circulation device to form a third air chamber. The preferred solution is to adopt a three-step structure made of stainless steel, wherein the first step is arranged with circumferential through holes and limit slots, the end is chamfered, the second step diameter is 1~2mm smaller than the inner diameter of the main workpiece hole, and has an annular slot, and the third step diameter is about 5mm larger than the inner diameter of the main workpiece hole.

[0012] Preferably, the clamping ring is a highly elastic open ring with a trapezoidal cross section. A preferred solution is that the outer diameter in the initial state is slightly larger than the inner diameter of the main workpiece opening by 1-2 mm, and the minimum outer diameter after shrinkage is slightly smaller than the inner diameter of the main workpiece opening.

[0013] Preferably, the gas diffusion mechanism is an annular porous metal. A preferred solution is an integral annular mesh composed of multiple layers of fine stainless steel mesh, the outer diameter of which is substantially consistent with the second step in the weld matching mechanism.

[0014] Preferably, the fixing ring is a highly elastic open ring, and the air pipe is a hose. A preferred solution is that the air pipe is a high temperature resistant plastic hose.

[0015] The beneficial effects of the present invention are as follows: (1) when the present invention is suitable for full penetration pipe fillet weld structures, the protective gas can flow evenly through the back of the weld and form a stable and continuous atmosphere, thereby obtaining relatively good weld quality; (2) the present invention can effectively reduce the amount of protective gas used and reduce manufacturing costs; (3) the present invention is simple to operate, and the modular design has high versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of explosion decomposition of the present invention; Figure 2 It is a structural schematic diagram of the present invention; Figure 3 This is a gas flow schematic diagram of the present invention. In the figure: 1. gas circulation device, 2. weld matching mechanism, 3. clamping ring, 4. gas diffusion device, 5. fixing ring, 6. gas reflux regulator, 7. air pipe, 12. air inlet pipe, 11. shell, 13. air guide pipe, 14. end plug, 15. center pipe, 16. tail thread plug, F, gas flow direction, I, first air chamber, II, second air chamber, III, third air chamber, WP1, main workpiece, WP2, connecting pipe. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example: Figure 1 , Figure 2 As shown, a gas protection device for the back of a fillet weld of a pipe connection includes a gas circulation device 1, a weld matching mechanism 2, a clamping ring 3, a gas diffusion device 4, a fixing ring 5, a gas reflux regulator 6, an air pipe 7, an air inlet pipe 12, an outer shell 11, an air guide pipe 13, an end plug 14, a center pipe 15, and a tail threaded plug 16.

[0018] The weld matching mechanism 2 is installed on the gas circulation device 1 by threaded connection, the clamping ring 3 is installed in the annular groove on the weld matching mechanism 2, the gas dispersion device 4 itself has a certain elasticity and can be mounted on the weld matching mechanism 2 and fixed by the fixing ring 5 to form a weld matching mechanism 2 assembly, and the gas reflux regulator 6 is installed on the tail thread plug 16, and the size of the tail opening of the center tube 15 can be adjusted by rotating the adjustment position to achieve the adjustment effect. The air inlet pipe 12 , the housing 11 , the air guide pipe 13 , the end plug 14 , and the center pipe 15 are connected by sealed welding to form a gas circulation device 1 assembly, and the hose 7 is sleeved on the air inlet pipe 12 .

[0019] A complete set of equipment also includes a gas supply system, etc.

[0020] Instructions for using the device: Before using the device, Figure 1 As shown, first assemble and position the main workpiece WP1 and the connecting pipe WP2, select the weld matching mechanism 2 component that matches the main workpiece WP1 and install it on the gas circulation device 1 component, install the air pipe 7 on the air inlet pipe 12 and fasten it with steel wire, clamps, etc., align the device with the assembled workpiece and insert it with force, so that the clamping ring 3 is deformed and fits on the inner wall of the main workpiece WP1. The gas is introduced, and the gas enters the device from the air pipe 7, passes through the first air chamber I composed of the outer shell 11, the air guide pipe 13, and the center pipe 15, and then passes through the second air chamber II composed of the air guide pipe 13 and the center pipe 15, and enters the third air chamber II composed of the weld matching mechanism 2 and the air guide pipe 13. The gas flows out from the gas dispersion device 4, part of it flows out from the groove position, and part of it flows out from the open end of the pipe or flows out from the opening of the gas reflux regulator 6 through the center pipe 15, as shown in FIG. Figure 3 Then adjust the gas flow and the gas reflux regulator 6 to produce a more ideal protective atmosphere at the position of the gas diffusion device 4.

[0021] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A gas protection device for the back of a pipe fillet weld, used for a pipe fillet weld structure, the pipe fillet weld structure comprising a pipe and a main workpiece, characterized in that: The protection device includes a gas circulation device, a weld matching mechanism, a clamping ring, a gas dispersion device, a fixing ring, a gas reflux regulator and an air pipe. The weld matching mechanism is installed on the gas circulation device. The clamping ring is installed in the annular groove on the weld matching mechanism and can be clamped and fixed to the inner wall of the main workpiece. The gas dispersion device is installed at the gas outlet on the weld matching mechanism and fixed by the fixing ring. The gas reflux regulator is installed at the tail of the gas circulation device and can control the outflow of gas by adjusting the position of the thread. The protective gas enters the device from the air inlet of the gas circulation device through the air pipe, passes through the gas circulation device and the weld matching mechanism, and escapes from the position of the gas dispersion device to form a relatively uniform protective atmosphere on the back of the weld of the connecting pipe. A part of the protective gas escapes from the gap between the connecting pipe and the main workpiece, and the other part continues to flow into the connecting pipe and finally flows out from the gas reflux regulator through the reflux pipe in the center of the gas circulation device.

2. The back gas protection device for the fillet weld of a pipe according to claim 1 is characterized in that: The gas circulation device is a multi-chamber tubular metal structure, including an air inlet pipe, an outer shell, an air guide pipe, a center pipe, an end plug, and a tail threaded plug. The outer shell is fixed to the air guide pipe to form a first air chamber, the air guide pipe is fixed to the end plug and the center pipe to form a second air chamber, the air inlet pipe is connected to the outer shell and communicated with the first air chamber, and the air inlet pipe is connected to the air pipe.

3. The back gas protection device for the fillet weld of a pipe according to claim 2 is characterized in that: The outer edge of the inner end of the shell is provided with a thread, and the end of the thread is provided with a limiting step higher than the thread.

4. The back gas protection device for the fillet weld of a pipe according to claim 2 is characterized in that: The air guide tube is a tubular porous structure, connected to the central tube, the outer shell, and the end plug by welding, and multiple rows of openings are evenly distributed around the air guide tube.

5. The back gas protection device for the fillet weld of a pipe according to claim 2 is characterized in that: The end plug is cylindrical, the outer diameter of which matches the inner diameter of the air guide tube and is connected by welding, one end of which is provided with a thread, and the center is provided with a through hole, the inner diameter of which matches the outer diameter of the center tube and is connected by welding.

6. The back gas protection device for the fillet weld of a pipe according to claim 2 is characterized in that: The center tube is a straight tube and is fixed to the outer shell, the air guide tube and the end plug by welding. One end is open and the other end is fixed to the tail threaded plug by welding. Openings are arranged around the tail threaded plug. The tail threaded plug is threadedly connected to a gas reflux regulator. The gas reflux regulator is a hollow structure, one end of which is provided with a thread and cooperates with the tail threaded plug, and the inner diameter of the other end cooperates with the outer diameter of the center tube.

7. The back gas protection device for the fillet weld of a pipe according to claim 1 is characterized in that: The weld matching mechanism is a metal cup-shaped structure with multiple steps, which can be configured in various specifications according to the actual size of the workpiece. It has a cover at one end and a threaded hole in the center, and the thread matches the end plug. The interior is hollow and the inner wall has threads, and the threads match the outer shell. The weld matching mechanism is assembled with the gas circulation device to form a third air chamber.

8. The back gas protection device for the fillet weld of a pipe according to claim 1 is characterized in that: The clamping ring is a highly elastic open ring with a trapezoidal cross section.

9. The back gas protection device for the fillet weld of a pipe according to claim 1 is characterized in that: The gas diffusion mechanism is a ring-shaped porous metal.

10. The back gas protection device for fillet weld of pipe according to claim 1, characterized in that: The fixing ring is a highly elastic open ring, and the air pipe is a soft tube.

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