JPH0454215Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a heating device for an electric resistance welded pipe in which even if an inductor receives force in the vertical direction, it can absorb this force.

B. Summary of the invention The present invention provides an electric resistance welded pipe heating device in which a matching transformer is attached to the lower end of an elevating rod that is movably attached to a frame, and an inductor is provided below the matching transformer. On the other hand, by providing the matching transformer so as to be able to move up and down relatively, and by providing a biasing means for biasing the matching transformer downward with respect to the lifting rod, an impact force is transmitted from the ERW pipe to the inductor and the matching transformer. This prevents them from being damaged even if they are damaged.

C. Prior Art In an electric resistance welded pipe seam-welded by high-frequency welding, the seam welded portion is hardened by rapid cooling after welding, so the structure is improved by heating and annealing.

Conventionally, an induction heating apparatus shown in FIG. 7 has been used for such heating annealing. In the figure, 1a and 1b are electric resistance welded tubes, 2 is a roller for conveying electric resistance welded tubes 1a and 1b, 3 is a frame body, 4 is a lifting rod that can be raised and lowered with respect to the frame body 3, and 5 is a lifting rod 5. case 5 on the bottom edge of
A matching transformer is attached via a, and 6 is an inductor. In order to enable the lifting rod 5 to move up and down, the lifting rod 5 is screwed into a worm wheel 8 rotatably supported by a gear box 7, and a worm 10 attached to the output shaft of a motor 9 is engaged with the worm wheel 8. It's on. The frame body 3 has a pair of guide frames 1 facing downward and parallel to each other.
1 is attached, and the alignment transformer 5 is moved up and down in a stable state by a plurality of rotatable rollers 12 attached to the inside of each guide frame 11.

In such a heating device, the electric resistance welded tubes 1a and 1b
When the outer diameter changes as shown in the figure, the distance between the inductor 6 and the electric resistance welded tubes 1a and 1b is adjusted by raising and lowering the inductor 6, matching transformer 5, and lifting rod 4. By rotating the motor 9, the rotation of its output shaft is transmitted from the worm 10 to the worm wheel 8, and the elevating rod 4, etc., moves up and down, and due to the function of the worm 10 and the worm wheel 8, the weight of the matching transformer 5 moves the matching transformer 5. It will not fall down on its own.

However, as shown in FIG.
There is a large diameter portion 13 as a part that is not welded at the end of the
Therefore, in order to make the large diameter part 13 pass under the inductor 6, the matching transformer 5 must be raised once. If this operation is incorrect, the large diameter part 13 will collide with the inductor 6, causing the inductor to collapse. 6 and matching transformer 5 may be destroyed. Further, a large diameter portion may occur not only at the end portions of the electric resistance welded tube but also at the intermediate portion, and the above-mentioned problem also occurs in such a case.

In order to solve this problem, a heating device for electric resistance welded pipes as shown in FIG. 8 has been proposed. In the figure,
Portions with the same reference numerals as those in FIG. 7 are the same, and therefore their description will be omitted. As shown in the figure, the center portion of a beam 16 is rotatably supported on the upper part of the column 14 via a pin 15, and the lower ends of a pair of guide frames 11 are fixed to one end of the beam 16. On the other hand, a rod 18 of a fluid cylinder 17 such as a pneumatic cylinder whose base end is rotatable is rotatably connected to the other end of the beam 16 via a metal fitting 19.

In such a heating device, when the large diameter portion (not shown) of the electric resistance welded tube 1b pushes up the inductor 6, a force is applied to the inductor 6 → matching transformer 5 → lifting rod 4 → guide frame 11 → one end of the beam 16. is transmitted, beam 1
6 rotates clockwise in the figure around the pin 15. When the beam 16 rotates clockwise, the rod 18 enters into the fluid cylinder 17, and at the same time, the fluid is compressed into the fluid cylinder 17 by the piston, and serves as a buffer when the inductor 6 is pushed upward. When the large diameter portion of the electric resistance welded tube 1b passes under the inductor 6, the rod 18 is raised by the action of the fluid cylinder 17, and the inductor 6 is lowered to return to its original position.

D. Problems to be solved by the invention However, such a heating device has the following problems. The lifting and lowering speed of the rod of the fluid cylinder is slow, and it takes time for the inductor to return to its original position after the large diameter section of the ERW tube has passed, and during that time, a considerable length of the ERW tube is sufficiently heated. The pipe passes under the inductor without being heated, causing a large amount of pipe loss due to poor heating. Furthermore, as shown in FIG. 8, the heating device tends to be large-scale.

Therefore, an object of the present invention is to provide a heating device for an electric resistance welded pipe that solves such problems.

E Means for solving the problem The structure of the present invention to achieve this purpose is as follows:
A vertically extending lifting rod is attached to the frame so that it can be raised and lowered, and a matching transformer is attached to the lower end of the lifting rod, and an inductor is provided below the matching transformer for induction heating of the electric resistance welded pipe that is transported in the horizontal direction. In the heating device for an electric resistance welded pipe, the matching transformer is provided to be able to move up and down relative to the lifting rod, and urging means is provided for urging the matching transformer downward with respect to the lifting rod. It is characterized by

F Effect When the distance between the inductor and the ERW tube is set to a constant value and the ERW tube is conveyed in the direction of its axis, if the ERW tube has a large diameter section, the inductor will be pushed upwards. .
Since the matching transformer is movable up and down with respect to the elevating rod and is urged downward via the urging means, the inductor and matching transformer move upward against the urging force of the urging means. When the large diameter portion of the electric resistance welded tube passes under the inductor, the inductor and matching transformer are lowered by their own weight and biasing means. In this way, the inductor moves up and down following the passage of the large diameter portion of the electric resistance welded tube, and the response is quick, so no pipe loss occurs in the electric resistance welded tube due to poor heating.

G. Embodiment Hereinafter, the first embodiment and the second embodiment of the present invention are shown in the drawings.
This will be explained in detail based on examples.

First, a first embodiment will be described based on FIG. Note that the first embodiment is a partial improvement of the conventional heating device shown in FIG. 7, so the same parts are given the same reference numerals and the explanation will be omitted, and only the different parts will be explained.

As shown in the figure, the present invention is provided with a buffer means 21 between the lifting rod 4 and the matching transformer 5.
A in FIG. 1 to explain the structure of the buffer means 21.
An enlarged view of the section is shown in FIG. 2, and a view taken along the - arrow in FIG. 2 is shown in FIG.

A pair of mounting brackets 22 parallel to each other are fixed above the case 5a, and the mounting brackets 22 and block 2 are connected with a block 23 sandwiched between the mounting brackets 22.
3 are connected by bolts 24. A hole 25 is formed in the center of the block 23 in the vertical direction, and the lower part of the lifting rod 4 is inserted through the hole 25. The lifting rod 4 is formed with a male thread, but a straight part 4a is formed at the lower part.
A male threaded portion 4b having a smaller outer diameter than the straight portion 4a is formed at the lower end. The length of the straight portion 4a is sufficiently larger than the length of the hole 25, and with the straight portion 4a inserted into the hole 25, the stopper 26 is inserted between the nut 27 and the straight portion 4a. A spring receiver 28 having a female threaded portion and a slot above the straight portion 4a.
are screwed together and fixed to the lifting rod 4 by bolts 29. In this way, by inserting the straight part 4a into the hole 25, the matching transformer 5 is configured to be able to move up and down with respect to the lifting rod 4, and a coil spring as a biasing means is installed between the spring receiver 28 and the block 23. 30 is interposed.

Further, in this embodiment, means for detecting the amount of rise of the inductor is provided. As shown in FIG. 3, the lower end of the stud 31 is screwed into an extension 26a, which is a horizontal extension of a portion of the stopper 26, and is locked with a nut 49. The upper end of the stud bolt 31 has a tapered surface 32.
The detector 32 having a slot and a bolt 33
has been fixed through. On the other hand, a limit switch 34 as a detector is attached to the upper surface of the mounting bracket 22 on one side via a bolt 35.
The limit switch 34 has a movable part 34a that is movable in the horizontal direction, and a roller 34b that comes into contact with the detector 32 is attached to the tip of the movable part 34a. Note that a proximity switch may be provided instead of the limit switch.

Next, the operation of such a heating device will be explained. When the large diameter portion 13 comes into contact with the ERW tube 1b and the large diameter portion 13 comes below the inductor 6, the matching transformer 5 rises together with the inductor 6, and the block 23 pushes up against the biasing force of the coil spring 30. It will be done. At this time, a gap is created between the block 23 and the stopper 26, but when the large diameter portion 13 passes below the inductor 3, the inductor 6
Then, the matching transformer 5 is lowered, and the lowering of the block 23 is stopped by the stopper 26. In this way, the inductor 6 and matching transformer 5 rise, so
It will not be damaged by the large diameter portion 13, and after rising, it will immediately descend due to its own weight and the biasing force of the coil spring 30, so no pipe loss will occur due to poor heating.

On the other hand, when the inductor 6 and the like are pushed up, the limit switch 34 rises together with the mounting bracket 22.
Then, since the detector 32 is integrated with the lifting rod 4 and does not move, the movable part 34a that is in contact with the detector 32 via the roller 34b retracts.
It is detected that the inductor 6 etc. have been pushed up.
If the limit switch 34 is connected to an alarm or recorder, it is possible to issue and record an alarm. The large diameter portion 1 of the ERW tube 1a is connected below the inductor 6.
3 passes, the limit switch 34 is lowered together with the matching transformer 5, and the movable portion 34b protrudes and returns to the non-detection state. In this way, the rising and falling operations of the inductor 6 can be confirmed, which is convenient for later checking whether there is any abnormality in the inductor 6 or the matching transformer 5.

Next, a second embodiment of the present invention will be described based on FIGS. 4 to 6.

As shown in Fig. 4, the frame 3 assembled into a rectangular shape
A pair of mutually parallel guide frames 11 extending in the vertical direction are fixed to each of the guide frames 6 . Note that both guide frames 11 are coupled at the rear of the matching transformer 5 in the figure. In the figure, bases 37 and 38 are fixed on the left and right guide frames 11.
A lifting rod 4 is provided vertically extending through the rods 8. A worm wheel 8 is screwed to each lifting rod 4 as in the first embodiment.
A worm (not shown), which is fixed to a connecting shaft 39 integral with the output shaft of the motor 9, is engaged with each of the worm wheels 8. The matching transformer 5 is housed in a case 5a, and the lower ends of the two lifting rods 4 are attached to both sides of the case 5a through buffer means 40, respectively.

The structure of the buffer means 40 is shown in FIG. 5, which is an enlarged view of section B in FIG. 4, and FIG. 6, which is a view taken in the direction of the - arrow in FIG. As shown in FIG. 5, a mounting seat 42 is attached to the top of the case 5a via bolts 41, and a block 44 is attached to the side of the mounting seat 42 via bolts 43. Embodiment 1 will be described below except that the shape of the limit switch 34 is different.
Since it is the same as that, the explanation of the buffer means will be omitted.

In this embodiment, since there is a space above the matching transformer 5, a terminal 45 for power supply is arranged in the center, and a cable 46 is connected to each terminal 45. Further, on the outside of the terminal 45, a cooling water inlet 47 and a drain port 48 for cooling the inside of the winding of the transformer are arranged.

According to such a heating device, a pair of lifting rods 4
Since the matching transformer 5 is raised and lowered through the Power supply and water supply can be easily carried out through 48.

Note that since the matching transformer and the like are heavy, each component is less likely to be damaged if the matching transformer and the like easily rise when the large diameter portion of the electric resistance welded tube comes into contact with the inductor. Therefore, frame 3 (Fig. 1) or 36 (Fig. 4)
(Fig.), attach a pulley to the support, hang a wire rope around the pulley, connect a matching transformer to one end of the wire rope, and connect a balance weight to the other end.

In addition, in general, many heating devices that induction heat the seam welds of ERW pipes have a structure in which the inductor follows the movement of the seam welds that rotate in the circumferential direction during transportation. The device can also be directly applied to a heating device equipped with such follow-up means.

Furthermore, the conventional heating device shown in FIG. 8 can also be made into a heating device to which the lifting device of the present invention is applied. That is, the rod 18 and fluid cylinder 17 in FIG. 8 may be replaced with the lifting rod 4 and mounting bracket 22 of the present invention shown in FIGS. 2 and 3.

H. Effects of the invention As explained above, according to the invention, the matching transformer is provided so that it can be raised and lowered relative to the lifting rod, and a biasing means is provided for urging the matching transformer downward with respect to the lifting rod. Therefore, when the large diameter portion of the electric resistance welded tube moves below the inductor and pushes the inductor upward, the inductor is pushed up together with the matching transformer against the urging force of the urging means. Therefore, there is no risk that the contacts etc. will be damaged. Further, when the large diameter portion passes under the inductor, the inductor immediately descends due to the urging force of the urging means and the weight of the matching transformer and the like. Therefore, there is no possibility that a portion of the electric resistance welded pipe is not heated properly, resulting in pipe loss.

[Brief explanation of the drawing]

1 to 6 show embodiments of the heating device for electric resistance welded pipes according to the present invention, FIGS. 1 to 3 relate to Embodiment 1, FIG. FIG. 3 is an enlarged view of part A in the figure, FIG. 3 is a - arrow view of FIG. 2, FIGS. FIG. 6 is an enlarged view of part B, FIG. 6 is a view taken along the - arrow in FIG. 5, and FIGS. 7 and 8 are structural diagrams of a conventional electric resistance welded tube heating device. 1a, 1b...Erw tube, 2...Roller, 3,3
6... Frame body, 4... Lifting rod, 5... Matching transformer, 6... Inductor, 9... Motor, 13... Large diameter section, 21, 40... Buffer means, 25... Hole, 2
6...Stopper, 28...Spring receiver, 30...Coil spring.

Claims (1)

[Claims for Utility Model Registration] A vertically extending lifting rod is attached to the frame so that it can rise and fall, and a matching transformer is attached to the lower end of the lifting rod, and below the matching transformer there is an electric resistance welded pipe that is conveyed horizontally. In a heating device for an electric resistance welded pipe equipped with an inductor for induction heating, the matching transformer is provided so as to be movable up and down relative to the lifting rod, and the matching transformer is attached downwardly with respect to the lifting rod. A heating device for an electric resistance welded pipe, characterized in that it is provided with a biasing means for biasing the electrical resistance welded pipe.