JPH0556232B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a welding device for welding tubes and tube sheets for manufacturing multi-tube cans such as heat exchangers, and more specifically, to a welding device for welding tubes and tube sheets for manufacturing multi-tube cans such as heat exchangers.・Related to a welding device for welding tubes and tube sheets that can reduce weight.

[Conventional technology]

Conventionally, as this type of welding device, one having the configuration shown in FIG. 3 is known. To explain the welding device having this configuration, a centering device 14 is rotatably fitted into the front end portion 12 of the main shaft 11 into the tube 13.
A drive mechanism 16 such as an electric motor is disposed at the rear end 15, and a welding torch 17 is disposed to be rotated together with the centering tool 14 by the drive mechanism 16 via the rotating main shaft 11. (Unexamined Japanese Patent Publication No. 138448, 1982, U.S. Patent Application Publication No. 1983-
(See Publication No. 137587).

Here, the centering device 14 is usually used as a rod-shaped device having a plurality of grooves formed in the axial direction and having a variable diameter.
is disposed within a housing 18, and a handle 19 is integrally formed below the housing 18.

Then, this welding device inserts the centering tool 14 into the tube 13 inserted into the tube sheet 20, and
and the welding part 22 between the pipe end 21 and the welding torch 17
After positioning the non-consumable electrode 23 made of tungsten or the like by welding so as to maintain a constant distance from the tip thereof, the drive mechanism 16 is driven to rotate the main shaft 11 and the centering device 14, so that the non-consumable electrode 23 is arranged on the main shaft 11. The welding torch 17 is rotated forward and backward every rotation, and the electrode 23 generates a welding arc to weld the welded portion 22.

This welding device has an excellent function in that it can automatically weld pipes and tube sheets in all positions.

[Problems to be Solved by the Invention] However, the above-mentioned welding device has the following problems. That is, since the handle is integrally formed at the bottom of the housing, that is, the handle is integrally fixed in a direction perpendicular to the axial direction of the housing, it may interfere with the pipes, etc. that are being welded. Its workability decreases.

A centering device that fits into a pipe that is welded to the tip of the main shaft, which is rotationally driven by the drive mechanism, is directly or indirectly connected and rotates with the main shaft, so that the load on the drive mechanism is reduced. Since it is quite large, the drive mechanism must have a somewhat sturdy structure.

The casing (housing) has a fixed shape,
Furthermore, since the drive mechanism is fixed, the structure needs to be made more robust in order to arrange the welding torch on the drive mechanism.

As the structure of the welding device itself becomes larger, it inevitably becomes heavier.

When a welding wire reel is disposed at the rear of the welding device, its weight increases further, making it difficult for an operator to carry out welding work while supporting it with one hand.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a welding device for welding a tube and a tube sheet, which is compact in size and light in weight.

[Means to solve the problem]

The apparatus for welding a tube and a tube sheet of the present invention to achieve the above-mentioned object rotates along a welded part formed by a tube sheet and a tube end of a tube inserted into the tube sheet. a welding torch that performs welding while welding, a center rod that is inserted and fixed into the pipe to maintain a constant distance between the tip of the non-consumable electrode of the welding torch and the welding part and determine the welding position, and a rear end of the center rod. a fixed shaft attached to the housing; a handle provided at the rear end of the fixed shaft; a housing that holds the welding torch and rotates about the fixed shaft; and a drive mechanism for rotationally driving the housing, and the center rod, the fixed shaft, and the handle are arranged on the same line.

In addition, in the above explanation, "with the fixed axis as the center position"
This means that the fixed shaft does not rotate, but rather uses the fixed shaft as a supporting shaft.

[Effect]

Since the pipe-to-tube sheet welding device of the present invention has the center rod, fixed shaft, and handle on the same line, it does not interfere with the pipes being welded, improving work efficiency. It works like this. In addition, since the center rod and fixed shaft do not rotate, the load on the drive mechanism can be reduced.
It works to make the drive mechanism smaller and lighter, and to hold the welding device body in a stable state relative to the pipe.

In addition, since the handle is attached to the rear end of the fixed shaft and on the same line, it acts so that the center rod can be inserted and fixed into the pipe by pressing it with a light force.

〔Example〕

Embodiments of the present invention will be specifically described below with reference to the drawings. Here, FIG. 1 is a partially cutaway side view showing an embodiment of the present invention, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG. 3 is a partially cutaway side view of a conventional device.

The welding device for welding a tube and a tube sheet according to this embodiment is roughly divided into a drive mechanism 31, a fixed shaft 32, and a welding torch 33.
and a centering device 34.

The drive mechanism 31 is usually formed by an electric motor and is arranged around the intermediate portion of the fixed shaft 32. The driving force of the drive mechanism 31 is transferred to the fixed shaft 32.
The rotational force of the drive mechanism 31 rotates the rotary body 35, and the welding torch 33 disposed on the rotary body 35 rotates at a constant rate. It is configured as follows.

Here, the welding torch 33 is configured to rotate in forward and reverse directions by detecting the moving position of the welding torch with a detection mechanism 36 disposed between the rotating body 35 and the fixed shaft 32. That is, when the welding torch 33 rotates once in one direction from the zero point, the detection mechanism 36 detects the moving position of the welding torch 33, and after stopping the generation of the welding arc, the drive mechanism 31 rotates the welding torch 33 by about 45 degrees further in the moving direction. Then, when the welding torch 33 is returned to the zero point and rotated once in the opposite direction while generating a welding arc as detected by the detection mechanism 36, the position is detected by the detection mechanism 36 and the welding arc is generated. The welding torch 33 is then rotated about 45 degrees in the same direction and returned to the zero point again to perform welding, and in the event of an emergency, it is driven so that an emergency stop and reset can be performed at the same time. Configuring.

Note that the detection mechanism 36 can be easily configured by a conventionally known combination of a limit switch and a timer circuit, for example, and a person skilled in the art can easily construct a specific circuit and device for this sequence circuit using the above-described operating method. Therefore, the specific configuration will be omitted.

With this configuration, only one detection mechanism 36 is required, so that the configuration of the entire welding apparatus can be further simplified.

The fixed shaft 32 has a centering device 34 (described later) at its tip, a handle 37 at its rear end, and a rotating body 35 rotated by a drive mechanism 31 around its center. The structure is more traditional. In addition, the centering device 34 is connected to the fixed shaft 3
2, a heat radiating member 38, and an insulating member 45.

The heat dissipating member 38 is formed of a shaft member having an uneven shape in the circumferential direction of the shaft, and is formed on the front end side, and the insulating member 45 is formed of Bakelite on the rear end side of the heat dissipating member 38. With this configuration, it is possible to reduce the difference in heat capacity between the tube and the tube sheet, and to avoid the effects caused by erroneous firing of the welding arc from the welding torch 33.

Conventionally, regarding this point, centering device 3
This problem has been solved by drilling a cooling water hole in the 4 or shaft and letting the cooling water flow in and out of this hole, but this configuration has the problem that the structure of the device becomes large. With the above configuration, such problems can be avoided.

The welding torch 33 has a commonly used configuration, and uses a non-consumable electrode 39 made of tungsten or the like as its core wire. The tip of the electrode 39 of this welding torch 33 is connected to the tube 40 and the tube plate 4.
It is disposed on a rotating body 35 so as to be able to rotate so as to face the welded portion with 2.

It is preferable that the electrode 39 of this welding torch 33 has a structure in which its protruding length can be automatically maintained at a constant length. Normally, when it is worn out, an operator performs centering, but this work requires a certain degree of skill.

The structure is such that the electrode 39 can be centered in accordance with changes in the gas pressure of the shielding gas supplied into the welding torch 33.

The centering device 34 has four leaf springs 42 at its tip.
is pressed by a spring-like spring 43 from the rear end so that it protrudes outward at the center, and a stopper 44 for changing the spring force of the spring 43 is disposed at the rear end.

When inserted into the tube 40, the leaf spring 43 and the stopper 44 are configured to support the inside of the tube 40 at two locations on their respective outer circumferential surfaces.

Further, in this centering device 34, the integral part of the leaf spring 42 and the spring-like spring 43, and the stopper 44 part can be removed as parts, and the tube 40
It is configured so that it can be adjusted to the inner diameter of the pipe and can be repaired as desired. Further, the heat dissipating member 38 and the insulating member 45 are also configured to be removable.

Next, the operation of this embodiment will be explained based on the above configuration. Here, a configuration using a ring of filler material as the welding rod (filler material) will be described.

First, after placing the above-mentioned ring around the tube, the centering tool 34 disposed at the tip of the fixed shaft 32 by the handle is inserted into the tube 40 inserted into the tube plate 42, and the tube is removed. a welded portion 46 between the plate 42 and the end of the tube 40;
The welding position is determined so that the distance between the tip of the non-consumable electrode 39 made of tungsten or the like of the welding torch 33 is kept constant.

Next, drive the drive mechanism 31 such as an electric motor,
By rotating the rotary body 35 disposed around the fixed shaft 32 with the fixed fixed shaft 32 as the center position, the welding torch 33 is rotated together, and a gap between the rotary body 35 and the fixed shaft 32 is rotated. The moving position of the welding torch 33 is detected by the disposed detection mechanism 36, and the welding torch 33 is rotated forward and reverse every rotation. During the rotation, a welding arc is generated by the electrode 36, which acts to weld the welded portion.

In the above embodiments, the rotating body 35 is not limited to the shape of the housing as shown in the drawings, but may have a simple plate-like configuration, and in this case, normally only the drive mechanism 31 is housed in the housing. The configuration is as follows.

Further, it is clear that the centering device 34 may have a configuration similar to that of a conventional one, and may have any configuration as long as it can be fitted into the tube 40. In addition, welding torch 33
It is clear that the moving position detection mechanism 36 may also have other configurations.

〔Effect of the invention〕

As is clear from the above description, according to the pipe-to-tube sheet welding device of the present invention, the center rod, the fixed shaft, and the handle are provided on the same line, so that the welding of the pipe, etc. This has the effect of improving workability by not getting in the way.

Further, according to the welding device for welding a tube and a tube sheet of the present invention, since the center rod and the fixed shaft do not rotate, the load on the drive mechanism can be reduced, the drive mechanism can be made smaller and lighter, and the welding device This has the effect that the main body can be held in a stable state relative to the tube.

Further, according to the welding device for welding a pipe and a tube plate of the present invention, since the handle is attached to the rear end of the fixed shaft and on the same line, the center rod can be inserted and fixed by pressing it into the pipe with a light force. have an effect.

Therefore, since the configuration can be simplified, it is possible to provide a welding device for welding a tube and a tube sheet that is smaller and lighter in weight.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG. 3 is a partially cutaway side view of a conventional device. 31... Drive mechanism, 32... Fixed shaft, 33...
Welding torch, 34... Centering instrument, 35... Housing (rotating body), 36... Detection mechanism, 37...
handle.

Claims (1)

[Claims] 1. A welding torch that performs welding while rotating along the welded part formed by the tube sheet and the tube end of the tube inserted into the tube sheet, and the tip of the non-consumable electrode of the welding torch and the above-mentioned welding. a center rod inserted and fixed into the pipe for positioning the weld while keeping a constant distance from the center rod; a fixed shaft attached to the rear end of the center rod; a handle provided at the rear end of the fixed shaft; It has a housing that holds the welding torch and rotates around the fixed shaft, and a drive mechanism that is inserted into the housing and rotates the housing, and the center rod, the fixed shaft, and the handle are connected to each other. A welding device for welding a tube and a tube sheet, characterized in that they are installed on the same line.