CN118650251A - A method for welding in a narrow space - Google Patents

Abstract

The invention discloses a method for welding in a narrow space, which relates to the field of welding and comprises the following steps: s1: removing a ceramic nozzle on a tungsten argon arc welding gun, and reserving a tungsten needle on the welding gun; s2: closing the narrow space of the piece to be welded to form a closed space; s3: introducing argon into the closed narrow space, and replacing original air in the narrow space by using the argon; s4: after the argon gas is substituted for the air, the welding gun in the step S1 is utilized to weld the welding position in the narrow space. The invention can ensure effective welding, and simultaneously ensure that the surface of the welding position is clean, and has high cleanliness.

Description

A method for welding in a narrow space

Technical Field

The invention relates to the field of welding, in particular to a method for welding in a narrow space.

Background Art

In workpieces, mechanisms, equipment and other devices, welding is often required for assembly; and there is often a small welding space. For example, in the field of cooling power generation equipment or energy supply equipment in a power plant, there is a water tank for cooling; when assembling the water tank, the partition and the box body need to be sealed and welded (there are multiple partitions in the box body, and the partitions are welded to the inner wall of the bottom of the box body). However, the gap between the partition and the box body is only about 15mm, and the space available for operators to operate is extremely narrow, making welding operations difficult.

At present, the welding method used for the above working conditions is arc welding, because only the welding rod can penetrate into the welding part; however, when this method is used for welding in a closed box, it is easy to leave welding slag and welding nodules that cannot be cleaned.

In the field of welding, there is also a method of welding, tungsten inert gas welding, which is a welding method with high cleanliness; however, a conventional tungsten inert gas welding torch has a ceramic nozzle, and the size of the ceramic nozzle is much larger than the size of the narrow space, resulting in the welding torch being unable to reach the welding site.

In summary, a technical solution for welding in a narrow space is needed.

Summary of the invention

The purpose of the present invention is to provide a method for welding in a narrow space in order to solve the above-mentioned problems, which can ensure effective welding while making the surface of the welding position clean and having high cleanliness.

The technical solution adopted by the present invention is as follows: A method for welding in a narrow space comprises the following steps:

S1: Remove the ceramic nozzle on the tungsten inert gas welding torch and keep the tungsten needle on the torch;

S2: Close the narrow space of the parts to be welded to form a closed space;

S3: introducing argon gas into the closed narrow space and using the argon gas to replace the original air in the narrow space;

S4: After the argon gas replaces the air, the welding position in the narrow space is welded using the welding gun in step S1.

Furthermore, before step S2, the welding gun without the ceramic nozzle and other components required for welding are first placed in the narrow space.

Furthermore, the opening of the narrow space is closed by using a gas protective cover or the workpiece to be welded is placed in a closed gas protective cover to complete the closed space in the preparation step S2.

Furthermore, the gas protection cover is made of a transparent material.

Further, the gas protection cover has an operation hole.

Further, the operation hole is arranged at a position close to the top of the gas protection cover, or/and an operation glove is provided at the operation hole, and the operation glove seals the operation hole.

Furthermore, an air inlet and an air outlet are provided on the closed space, and the air inlet and the air outlet are both connected to the interior of the closed space.

Furthermore, the air inlet is located at the bottom of the closed space, and the air outlet is located at the top of the closed space.

Furthermore, the flow area of the air inlet is larger than the flow area of the air outlet.

Further, in step S3, the oxygen content in the closed space is measured by an oxygen meter; until the oxygen meter cannot display the oxygen content or the oxygen content is lower than the set value, it is determined that the argon gas has completed the replacement of the air.

Furthermore, before step S4, welding is first performed on a test welding workpiece; if the test welding workpiece can be welded normally for a certain distance, the workpiece to be welded is welded; otherwise, it is considered that the argon concentration is insufficient and the workpiece to be welded is not welded.

In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

Aiming at welding in narrow spaces, the present invention adopts a tungsten inert gas arc welding torch without a ceramic nozzle for welding. In combination with an argon atmosphere, the welding torch can effectively reach the welding position of the workpiece to be welded, so that the weld will not produce welding slag and welding nodules, the surface is clean and tidy, and the cleanliness of the narrow space will not be affected.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a schematic diagram of the steps of the present invention;

FIG2 is a schematic diagram of the welding position of the box body and the partition disclosed in the present invention;

Fig. 3 is a schematic cross-sectional view along the A-A direction in Fig. 2;

Markings in the figure: 1-box; 2-partition; 3-narrow space; 4-gas protection cover; 41-operation hole; 5-air inlet; 6-air outlet.

DETAILED DESCRIPTION

In the description of the present invention, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when used. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

In addition, if the terms "horizontal" or "vertical" appear in the description of the present invention, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

In the description of the present invention, it is also necessary to explain that, unless otherwise clearly stipulated and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

Example 1

As shown in FIG. 1 to FIG. 3, a method for welding in a narrow space is described by welding a partition 2 in a water tank body 1. The part to be welded is a water tank, and the method includes the following steps:

S1: Remove the ceramic nozzle from the tungsten inert gas arc welding gun and keep the tungsten needle on the welding gun; then put the welding gun with the ceramic nozzle removed and other parts required for welding into the box 1; among which, other parts required for welding include but are not limited to welding wire, test welding workpiece, etc.; ensure that after the water tank is closed, there are enough tools for welding to avoid opening the water tank again to destroy the argon atmosphere.

S2: Close the narrow space 3 of the workpiece to be welded to form a closed space; specifically, use the gas protection cover 4 to close the opening of the water tank or place the water tank in the closed gas protection cover 4 to provide a basis for the subsequent formation of an argon atmosphere in the water tank.

S3: Argon gas is introduced into the closed water tank, and the original air in the narrow space 3 is replaced by the argon gas, so that the closed space is filled with a high concentration of argon gas atmosphere.

S4: After the argon gas replaces the air, the connection position between the bottom plate of the water tank and the partition 2 is welded using the welding gun without the ceramic nozzle in step S1.

The method disclosed in this embodiment aims at welding in a narrow space 3. A tungsten inert gas arc welding torch without a ceramic nozzle is used for welding. In an argon atmosphere, the welding torch can effectively reach the welding position of the workpiece to be welded, so that the weld will not produce welding slag and weld nodules, the surface is clean and tidy, and the cleanliness of the narrow space 3 will not be affected.

It should be noted that the principle and effect of this method are similar to those of conventional tungsten inert gas welding, but it can be particularly used in narrow spaces 3, especially narrow spaces 3 that ceramic nozzles cannot enter, so that tungsten inert gas welding can be used, thereby producing the beneficial effects brought by tungsten inert gas welding.

Example 2

On the basis of Example 1, a specific implementation of the "gas protection cover 4" is further proposed.

In a feasible implementation manner, the gas protection cover 4 is made of a transparent material, such as glass, so that an operator can observe the welding condition of the water tank and the partition 2 from outside the gas protection cover 4 .

In a feasible implementation manner, the gas shield 4 has an operation hole 41 , which facilitates an operator outside the gas shield 4 to operate the welding gun with the ceramic nozzle removed through the operation hole 41 for welding.

Furthermore, since the density of argon is higher than that of air, and the welding position between the box body 1 and the partition 2 is located at the bottom of the box body 1, the operation hole 41 is set near the top of the gas protection cover 4, so that the operation hole 41 will not destroy the argon atmosphere deposited in the box body 1, thereby ensuring that the welding can be carried out in a stable argon atmosphere.

Or/and, operating gloves are provided at the operating hole 41, similar to the connection between the gloves and the operating hole 41 in the glove box, the operating gloves seal the operating hole 41, reduce the argon leakage points, and improve the stability of the argon atmosphere in the closed space; and the presence of the operating gloves can reduce the damage to the operator during welding.

Example 3

On the basis of any one of the implementations in Examples 1-2, a specific implementation of "argon gas replacing air" is further proposed.

A feasible implementation manner is that an air inlet 5 and an air outlet 6 are opened on the closed space, and the air inlet 5 and the air outlet 6 are both connected to the interior of the closed space, that is, argon enters from the air inlet 5, and air and argon flow out from the air outlet 6, thereby completing the air replacement in the closed space; specifically, if the gas protective cover 4 is only the top opening of the closed box body 1, the water inlet hole at the bottom of the box body 1 can be used as the air inlet 5, and the air outlet 6 is opened on the gas protective cover 4; if the entire box body 1 is in the gas protective cover 4, the air inlet 5 is arranged at the bottom of the gas protective cover 4, and the air outlet 6 is arranged at the top of the gas protective cover 4; it can be known that the air inlet 5 is located at the bottom of the closed space, and the air outlet 6 is located at the top of the closed space. This arrangement also utilizes the fact that the density of argon is higher than that of air, so that the argon can completely replace the air in the closed space.

In a feasible implementation manner, the flow area of the air inlet is larger than the flow area of the air outlet, so that the flow resistance of argon gas entering the closed space is smaller than the flow resistance of argon gas flowing out of the closed space, thereby improving the stability of the argon gas atmosphere in the closed space.

Example 4

On the basis of any one of the implementations in Examples 1-3, a specific implementation of "determining argon concentration" is further proposed.

A feasible implementation method is that in step S3, the oxygen content in the enclosed space is measured by an oxygen meter to ensure that the oxygen content in the enclosed space is extremely low; specifically, if the oxygen meter cannot display the oxygen content, it means that the oxygen content in the enclosed space is extremely low or close to 0; or after the oxygen content is lower than the set value, it is determined that the argon gas has replaced the air. The set value can be obtained through a limited number of tests and will not be described in detail in this manual.

A feasible implementation method is to perform welding on a test workpiece before step S4; if the test workpiece can be welded normally for a distance, it proves that the argon concentration can meet the welding requirements, so that the box 1 and the partition 2 can be welded; otherwise, it is considered that the argon concentration is insufficient and the workpiece to be welded is not welded.

The present invention is not limited to the aforementioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims (10)

1. A method for welding in a confined space, characterized by: the method comprises the following steps:

s1: removing a ceramic nozzle on a tungsten argon arc welding gun, and reserving a tungsten needle on the welding gun;

S2: closing the narrow space (3) of the piece to be welded to form a closed space;

S3: introducing argon into the closed narrow space (3), and replacing original air in the narrow space (3) by using the argon;

S4: after the argon gas is substituted for the air, the welding gun in the step S1 is used for welding the welding position in the narrow space (3).

2. The method according to claim 1, characterized in that: before step S2, the welding gun with the ceramic nozzle removed and other components required for welding are placed in a narrow space (3).

3. The method according to claim 1, characterized in that: the gas protection cover (4) is used for sealing the opening of the narrow space (3) or the piece to be welded is placed in the sealed gas protection cover (4), so that the sealed space in the preparation step S2 is completed.

4. A method according to claim 3, characterized in that: the gas shield (4) is made of transparent material.

5. A method according to claim 3, characterized in that: the gas shield (4) has an operation hole (41).

6. The method according to claim 5, wherein: the operation hole (41) is arranged at a position close to the top of the gas protection cover (4), or/and the operation hole (41) is provided with an operation glove, and the operation glove seals the operation hole (41).

7. The method according to claim 1, characterized in that: an air inlet hole (5) and an air outlet hole (6) are formed in the closed space, and the air inlet hole (5) and the air outlet hole (6) are communicated with the inside of the closed space.

8. The method according to claim 7, wherein: the air inlet hole (5) is positioned at the bottom of the closed space, and the air outlet hole (6) is positioned at the top of the closed space.

9. The method according to claim 7, wherein: the flow area of the air inlet hole (5) is larger than that of the air outlet hole (6).

10. The method according to claim 1, characterized in that: in step S3, measuring the oxygen content in the closed space by an oxygen meter; the argon gas is considered to replace air until the oxygen meter cannot display the oxygen content or the oxygen content is lower than a set value; or/and before the step S4, welding is carried out on the test welding workpiece; if the test welding workpiece can be welded normally for a certain distance, the workpiece to be welded is welded; otherwise, the argon concentration is considered to be insufficient, and the piece to be welded is not welded.