JPH0442072Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to an impeder used in high frequency electric resistance welded pipe welding.

Summary of the invention This invention covers a ferrite core placed on the outer periphery of the rod with an insulating tube, and a small-diameter part that is fitted and inserted into the end opening of the insulating tube and closes the opening at both ends of the insulating tube. A first holder and a second holder each consisting of a stopper part that prevents the cylinder from moving in the axial direction are fitted and fixed to the rod to prevent the cylinder from moving outward in the axial direction, and the rod is provided with cooling water in the ferrite core. In an impeder used in high-frequency electric resistance welding pipe welding that has a water passage hole formed therein, the stopper part of at least one of each holder is configured to be removable, so that insulation can be improved by removing the stopper part. Only the cylinder can be moved in the axial direction, making it easy to replace the ferrite core.

BACKGROUND OF THE INVENTION Impeders are used in welding electric resistance welded pipes to efficiently conduct high-frequency current to the welding point.

FIG. 8 is a perspective view for explaining the principle of induction-type high-frequency electric resistance welding pipe welding, in which a pipe material 1 made of a metal plate is placed between a pair of supporting rolls 2a and 2b arranged oppositely. The edges of the tube material 1 are pressed against each other while being inserted and moved in the direction of the arrow. At this time, a high-frequency current i is applied to the tube material 1 itself using a high-frequency induction coil 3 to make the edge red-hot, and welding is performed at a welding point 4.

By the way, in order to make welding effective, it is desirable that all the high frequency current passes through the edge 5 of the tube material 1. However, in reality, the current not only flows concentrated at the edges, but also flows through the inside of the tube material 1, so the welding effect is not necessarily good. This is especially noticeable when the pipe diameter is small. Therefore, in order to make the current flow concentrated at the edge 5, an impeder 6 with a built-in ferrite core is used.
is inserted into the tube material 1 to reduce the current passing inside the tube material.

Next, FIG. 9 is a sectional view showing a state in which the impeder 6 is inserted into the tube material 1, and the impeder 6 is attached to the tip of a support shaft 8 fixed to a mounting block 7. 9 is impeder 6
It is a connection part consisting of a threaded part, etc. for attaching and detaching. 3 indicates the position of the induction coil, 2 indicates the position of the pressure roll, and 4 indicates the welding point. A cutting and removing device for cutting and removing the welding bead on the inner diameter side is further provided at the tip of the impeder 6 via a detachable connecting portion 10. The cutting machine is constructed by providing a cutting tool attachment part 11 via a connecting part 10, and attaching a cutting tool 13 for cutting and removing a welding beat to this cutting tool mounting part 11 via a cutting tool holder 12. Attachment part 11 has bite 1
It has a built-in hydraulic mechanism to raise and lower the 3. 14 is a cutting tool for cutting and removing the weld bead on the outer diameter side. 15 is a cooling water pipe for passing cooling water to the inside of the impeder 6 and the like.

Next, an example of the conventional impeder 6 will be explained using FIG. 6 and FIG. 7. The upper half of FIG. 6 is a sectional view. Figure 7 is D in Figure 6.
-D cross-sectional arrow view is shown.

In FIGS. 6 and 7, 20 is a rod made of non-magnetic wire or the like, and is provided with an axial water passage hole 21 and a radial water passage hole 23. Water hole 2
3 are generally provided at a plurality of locations in the circumferential direction.
Reference numeral 24 denotes a first holder, which is fitted to a stepped portion on the outer periphery of the rod 20 to prevent it from moving to the left in the figure. Reference numeral 25 denotes a water passage provided in the first holder 24 and communicates with a water passage hole 23 provided in the rod 20. 27 is an O-ring. A plurality of rod-shaped ferrite cores 33 are arranged around the outer periphery of the rod 20 as shown in FIG. A second holder 30 is fitted onto the outer periphery of the rod 20 and is prevented from moving rightward in the figure by nuts 36 and 37. Reference numeral 31 indicates drainage ports provided at a plurality of locations in the circumferential direction of the second holder 30. Reference numeral 34 is an insulating tube made of a cylindrical insulating material, in which the stepped small diameter portions of the first holder 24 and the second holder 30 are respectively engaged with openings at both ends, and the stopper portions which are the large diameter portions of both holders are fitted. are supported in a state in which movement in the axial direction is prevented by abutting the end faces. 26 and 32 are O-rings.

Therefore, the ferrite core 33 is the outer periphery of the rod 20, and the first holder 24 and the second holder 3
0 and the insulating cylinder 34. The water passage holes 21 and 23, the water passage 25, the gap between the ferrite cores 33, and the drainage hole 31 form a cooling water passage. Therefore, the cooling water supplied from the water passage hole 21 flows from left to right in the figure while cooling the ferrite core 33, and is discharged from the drainage hole 31.

Problems to be Solved by the Invention By the way, as the usage time of the impeder 6 becomes longer, the ferrite core 33 is subject to thermal influences and breaks down. And Ferrite Core 33
As the impeder performance deteriorates as the crushing progresses, it is necessary to replace the ferrite core 33 with a new one at regular intervals.

In order to replace the ferrite core 33 in the conventional impeder 6, loosen the nuts 36 and 37, move it together with the second holder 30 to the right in the figure, remove it from the rod 20, and then remove the insulating cylinder 34. The ferrite core 33 was replaced by similarly moving the ferrite core 33 to the right in the figure. This replacement work involves troublesome work such as moving the second holder 30 largely to the right and removing it. Moreover, as shown in FIG. 9, many impeders 6 are further provided with a cutting tool attachment section 11 at the tip thereof, so even the hydraulic piping for the hydraulic mechanism that moves the cutting tool mounting section 11 and the cutting tool 13 up and down. It is necessary to remove and replace the ferrite core 33 and then reassemble it, which makes it difficult to create a structure in which the hydraulic piping is housed within the rod 20.
Since piping and connecting portions are provided along the outer periphery of the impeder 6, the hydraulic piping may get in the way or be damaged.

Moreover, in narrow welding lines, impedance 6
In practice, it is often difficult to perform the above work with the ferrite still attached to the support shaft 8, so in many cases, the impeder 6 and the cutting tool attachment part 11, etc., are removed from the mounting block 7 together with the support shaft 8, and the above-mentioned ferrite After replacing the core, a large-scale work was being done to assemble the whole thing again.

Therefore, it takes a lot of time and effort to replace the ferrite core 33, and the welding line stops operating during that time, resulting in a decrease in productivity.

Means for Solving the Problems The present invention provides a structure in which the stopper part of at least one of the first holder and the second holder, which supports the insulating tube so as to prevent the axial movement of the insulating cylinder by the stopper part, is detachable. As a result, by removing the stopper part, only the insulating cylinder can be moved in the axial direction, and the ferrite core can be easily replaced.

Embodiments Hereinafter, the present invention will be explained in detail based on embodiments shown in FIGS. 1 to 5. It should be noted that the same parts as in the prior art are given the same reference numerals to simplify the explanation.

1 to 3 show a first embodiment of the present invention, and FIGS. 2 and 3 are cross-sectional views taken along the lines A--A and B--B in FIG. 1, respectively.

In the impeder 6 of the first embodiment shown in FIGS. 1 to 3, the first holder 24 includes a small diameter portion that closes the opening of the insulating tube 34 and a stopper portion that prevents the insulating tube 34 from moving in the axial direction. 28 and divided part 2
It is divided at 4a and configured to be detachable with bolts 29. As shown in FIGS. 1 to 3, when the stopper part 28 of the first holder 24 is attached, the insulating tube is connected to the stopper part 28 of the first holder 24 and the second holder 30, just like the conventional impeder. The ferrite core 33 is supported in a state where movement in the axial direction is prevented by the large diameter stopper part of the rod 20, and the ferrite core 33 is housed in the space formed by these and the outer periphery of the rod 20.

Next, when replacing the ferrite core 33, loosen the bolt 29 and remove the stopper part 28 from the first holder 24, and there will be nothing on the left side in the figure to prevent the movement of the insulating cylinder 34.
The insulating tube 34 can be moved to the left in the figure.

Therefore, the ferrite core 33 can be easily replaced by simply moving the insulating tube 34 to the left.

In addition, in the figure, the first holder 2 of the insulating cylinder 34
The reason why the inner diameter of the part where the small diameter part of No. 4 engages is formed as the small diameter part 35 which is smaller than the other inner diameter parts is to facilitate the movement of the insulating cylinder 34 and to make it easier to move the O-ring 2.
This is so that it can be done without damaging 6. Although this small diameter portion 35 is not necessarily required, it is preferable to provide it. Also, in the figure,
The stopper part 28 is located at one part of the outer periphery of the first holder 24.
Although it is provided in one portion, it may be provided in multiple locations in the circumferential direction or may be provided over the entire circumference.

In addition, as shown in FIG.
4, the stopper part of the second holder 30 may be detachably divided, and the insulating cylinder 34 may be moved to the right in the figure when replacing the ferrite core. . Furthermore, both the first holder 24 and the second holder 30 may be constructed so that the stopper portions are detachably divided. Note that the inner diameter dimension of the insulating tube 34 is the inner diameter dimension of the minimum inner diameter portion that allows the insulating tube 34 to be moved leftward or rightward to the extent that it is removed from the outer peripheral portion of the ferrite core 33.

Next, FIGS. 4 and 5 are diagrams showing a second embodiment of the present invention, and FIG.
This is an explanatory diagram viewed from the direction of arrow C, in which the stopper part is removed in Fig. 5A, and the removed stopper part is shown in B. In the impeder 6 in this second embodiment, a nozzle 40 is provided to spray cooling water also to the area immediately below the welding point 4 in FIG. 8 or 9 to eliminate molten products generated during welding. , which prevents molten products from depositing on the outer surface of the impeder 6. Reference numeral 41 denotes a water passage, and each water passage hole 4 in the radial direction is provided in the rod 20, the first holder 24, and the stopper part 28.
2, 43 and 44. Further, a water passage hole 22 for supplying cooling water is provided in the axial center of the rod 20 at the cutting edge of the cutting tool 13 for cutting and removing the weld bead on the inner diameter side as shown in FIG. A hydraulic pipe 45 is disposed within 22. An impeder having a structure similar to this structure is described in Japanese Patent Application No. 169136/1982.

In the impeder 6 in this embodiment, a nozzle 40 is integrally attached to the stopper portion 28. Therefore, the stopper part 2 is secured by the bolt 29.
8 and the nozzle 40 are integrally attached to the first holder 24.
It is attached and detached. Loosen the bolt 29, separate the stopper part 28 and the nozzle 40 at the divided part 24a of the first holder 24, and remove the insulating cylinder 3.
4 to the left in the figure, the ferrite core 33 can be easily replaced. Note that also in this embodiment, the first part of the insulating cylinder 34
A local small-diameter portion 35 is provided at the portion that engages with the holder 24, and this small-diameter portion 35
4 may be molded integrally with the insulating cylinder 34, or as shown in FIG.
It may also be provided by inserting and joining into the inner diameter of the.

Effects of the invention As explained above, in the impeder of the invention, the ferrite core can be easily replaced by simply removing the stopper provided on the first holder or the second holder and moving the insulating tube in the axial direction. I can do it. Therefore, it is possible to reduce the labor and time needed to replace the ferrite core. Furthermore, the down time of the welding line is shortened, which has the effect of improving productivity.

Also, if the tool attachment part is connected to the tip of the impeder, there is no need to remove the tool attachment part when replacing the ferrite core, and there is no need to disconnect the hydraulic piping for moving the tool up and down. Since there is no need for contacting the rod, it is not only very easy to replace the ferrite core, but it is also easy to store the hydraulic piping in the axial hole provided in the rod, eliminating the need for hydraulic piping to get in the way. There are effects such as being able to avoid damage caused by contact with the pipe material 1.

[Brief explanation of the drawing]

1 to 5 are diagrams showing embodiments of an impeder according to the present invention. Figures 1 to 3 are diagrams showing the first embodiment, and Figures 2 and 3 are diagrams showing the first embodiment, respectively.
FIG. 2 is a cross-sectional view along line A-A and a cross-sectional view along line B-B in the figure. 4 and 5 are diagrams showing the second embodiment, and FIG. 5 is a cross-sectional view taken along the line C--C in FIG. 4. 6 and 7 are diagrams showing examples of conventional impeders, and FIG. 7 is the D in FIG. 6.
-D is a cross-sectional view taken along the arrow. FIG. 8 is a perspective view illustrating the principle of induction type high frequency electric resistance welding tube welding, and FIG. 9 is a diagram showing a state in which the impeder is inserted into the tube material. 1...Pipe material, 3...Induction coil, 4...Welding point, 6...Impeder, 8...Support shaft, 11...
Bit attachment part, 13, 14... Bit, 20
... Rod, 24 ... First holder, 28 ... Stopper section, 30 ... Second holder, 33 ... Ferrite core, 34 ... Insulating cylinder, 40 ... Nozzle.

Claims (1)

[Scope of utility model registration request] An impeder used in high-frequency electric resistance welding pipe welding, in which a ferrite core is arranged around the outer periphery of a rod whose base end side is fixed via a support shaft, and an insulating cylinder is provided to cover the outer periphery of the ferrite core. a first holder comprising, at both ends of the insulating tube, a small diameter portion that is fitted and inserted into an end opening of the insulating tube to close the opening, and a stopper portion that prevents movement of the insulating tube in the axial direction; A second holder is fitted and fixed to each of the rods so as to prevent movement outward in the axial direction, and a water passage hole is formed in the rod to allow cooling water to flow through the ferrite core, and each of the holders is fitted with a second holder. An impeder characterized in that at least one of the stopper portions is configured to be detachable.