JPH1092562A - Induction heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deformation and contact face damage of an electric-resistance welded tube by setting the cylinder pressure lower than the total weight of an output voltage transformer, an inductor, and an upper guide roller. SOLUTION: The pressure of a cylinder 21 is set to be lower than the total weight of the output transformer 13, an inductor 14, and an upper guide roller 15 and jacks 11, 18 for adjustment are adjusted corresponding to the diameter of an electric resistance welded tube 3 to conform the rotation center of the inductor 14 and the center of the electric resistance welded tube 3. Then, the electric resistance weld pipe 3 is transported by a lower roller 2 and a welding part 4 is annealed by induction heating. At this point, the position of the welding part 4 is detected, a moving truck 10 is set along an arc-like guide 9, and the inductor 14 is made to follow the position alteration of the welding part 4. In the case the undulation and height setting of the electric resistance welded tube 3 are too small, the roller 15 tends to be lifted up and since the pressure of the cylinder 21 is set to be smaller than the weight of the appliances, the force applied to the electric resistance welded tube 3 is low and moreover in the case the roller 15 is pushed up by the force higher than the force applied to the welded tube 3, a rod of the cylinder 21 is extruded upward and the up-and-down movement of the welded part 4 can be absorbed and deformation of the electric resistance welded tube 3 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating apparatus for locally heating and annealing a welded portion of an electric resistance welded pipe.

[0002]

2. Description of the Related Art Generally, an ERW pipe is manufactured by bending a plate material continuously into an annular shape and welding the butted ends to manufacture an ERW pipe, and then removing the thermal distortion of the welded portion of the ERW pipe. In addition, an inductor is locally brought into proximity with the welded portion to perform local induction heating and annealing.

In a conventional induction heating apparatus for annealing an electric resistance welded pipe, as shown in FIGS. 4 and 5, an electric resistance welded pipe 3 is placed on a lower roller 2 attached to a transfer stand 1 with a welded portion 4 up. And are continuously transported. An inductor support frame 5 is provided above the electric resistance welded tube 3 and is supported vertically movable along a guide rail 8 attached to a support stand 7. As shown in FIG. 5, two arc-shaped guides 9 are provided inside the inductor support frame 5 in the front and rear directions, and the movable trolley 10 is turned on the left and right in an arc shape.

[0004] An output transformer mounting plate 12 is connected to an upper portion of the movable trolley 10 via a height adjusting jack 11. Further, an output transformer 13 is attached to a lower portion of the output transformer mounting plate 12, and an inductor 14 is further attached to the lower portion of the output transformer mounting plate 12 with a gap between the output transformer 13 and a front and rear of the inductor 14. Are provided with upper guide rollers 15, 15 which roll in contact with the upper part of the ERW pipe 3. The lower part of the inductor support frame 5 for integrally supporting these mechanisms is connected to a mount 17 via an emergency evacuation air cylinder 16 as shown in FIG. 4, and the lower part of the mount 17 is height-adjusted. Jack for
The mounting base 17 is connected to the support stand 18 and moves up and down along a guide rail 19 provided on the support stand 7.

In the above-mentioned heating device, the height adjusting jack 18 and the height adjusting jack 11 are adjusted in accordance with the diameter of the electric resistance welded tube 3 so that the center of rotation of the inductor 13 is adjusted to the center of the electric resistance welded tube 3. It is set so as to be rotated right and left on the arc-shaped guide 9 so as to coincide with each other. In this state, the electric resistance welded tube 3 is conveyed onto the lower roller 2, an electric current is supplied to the inductor 14 through the output transformer 13, and the welded portion 4 of the electric resistance welded tube 3 conveyed below is heated by annealing. I do.

In this case, the smaller the gap between the ERW pipe 3 and the inductor 14 is, the higher the heating efficiency is. However, since the ERW pipe 3 has undulation, the gap is set large in consideration of safety. Further, when there is a large swell exceeding the specified value, the emergency evacuating air cylinder 16 is actuated by detecting this, and the whole of the inductor supporting frame 5 rises to prevent collision with the inductor 14. . When the emergency evacuation is performed, heating of the ERW pipe 3 by the inductor 14 is not performed.

However, if there is a swell that is slightly smaller than the prescribed swell that is urgently evacuated, or if the height adjustment is set to be smaller than the actual diameter of the electric resistance welded tube 3, this is not the case. Upper guide roller 15, which contacts
A force acts to lift 15 upward. In this state, the upper guide rollers 15, 15 are connected to the inductor 14 and the output transformer.
13. Since the height adjusting jack 11 and the movable trolley 10 are integrally connected and there is no mechanism for absorbing the vertical movement, the total sum of these weights is directly applied to the ERW pipe 3. .

In such a state, the upper guide roller
15 always presses the ERW pipe 3 with a heavy weight, so that the ERW pipe 3 is deformed or the upper guide roller of the ERW pipe 3 is deformed.
There are problems such as the contact surface with the roller 15 being damaged and the upper guide roller 15 being severely worn. For this reason, in the conventional induction heating device, the upper guide roller 15, the inductor 14, the output transformer 13,
Although the height adjusting jack 11 and the movable trolley 10 are made as light as possible, there is a limit to the reduction in weight due to the capacity of the heating device.

[0009]

SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned drawbacks, and when the ERW tube has an undulation smaller than a prescribed swell that urgently retreats, or when the height of the inductor is adjusted in the actual ERW tube. Even if the diameter is set smaller than the diameter, the weight applied to the ERW pipe is reduced to prevent deformation of the ERW pipe, and to reduce the damage to the contact surface of the ERW pipe and the wear of the upper guide roller. It is an object of the present invention to provide an induction heating device capable of increasing the capacity of the apparatus.

[0010]

According to the present invention, there is provided an inductor support frame provided above an electric resistance welded tube to be conveyed, and a movable cart which turns left and right on an arcuate guide attached to the frame. A guide frame supported on the movable trolley via a height adjusting jack, an output transformer mounting plate supported on the guide frame via a cylinder, and An output transformer slidably penetrating through the guide frame, an inductor provided at a lower portion of the output transformer so as to face above the ERW pipe, and attached before and after the inductor. An upper guide roller that rolls in contact with the upper portion of the ERW pipe.

In the induction heating apparatus of the present invention, the pressure of the cylinder is set to be slightly smaller than the total weight of the output transformer, the inductor and the upper guide roller. Also, adjust the height adjustment jack according to the diameter of the ERW pipe, transport the ERW pipe, and energize the inductor through the output transformer,
The welded portion of the electric resistance welded pipe conveyed below this is annealed by induction heating.

The welded portion of the electric resistance welded pipe shifts right and left during conveyance. When the positional deviation of the welded portion is detected, the movable carriage is rotated along the arc-shaped guide, and the inductor moves to the position of the welded portion. Induction heating is performed while following the change. If the ERW tube has a swell that is smaller than the specified swell that urgently retreats, or if the height adjustment is set smaller than the diameter of the ERW tube, the upper guide roller that comes into contact with this A force to lift upward acts. In such a state, since the upper guide roller, the inductor and the output transformer are integrally connected, a force is applied to the ERW pipe to push them upward. However, since the pressure of the cylinder is set slightly smaller than the combined weight of the output transformer, the inductor and the upper guide roller, the force applied to the ERW pipe is small, and moreover, the upper guide is applied with a larger force. When the roller is pushed up, the cylinder extends upward to absorb the vertical movement of the upper guide roller.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIG.
This will be described in detail with reference to FIG. Transport stand 1
The electric resistance welded pipe 3 is continuously conveyed on the lower roller 2 attached thereto with the welded portion 4 facing upward. An inductor support frame 5 is provided above the electric resistance welded tube 3,
It is vertically movably supported along a guide rail 8 attached to a support stand 7. Inside the inductor support frame 5, arc-shaped guides 9 are arranged back and forth as shown in FIG.
And a frame-shaped movable cart 10 is rotated left and right in an arc shape.

A frame-shaped guide frame 20 is mounted on an upper portion of the movable carriage 10 via a height adjusting jack 11, and an output transformer mounting plate 12 is further connected thereto via a cylinder 21. . Further, as shown in FIG. 2, a guide frame 20 and a movable carriage 10 are provided below the output transformer mounting plate 12.
, An output transformer 13 is attached. In this case, the output transformer 13 penetrating the frame-shaped guide frame 20 is guided by the sliding portion 22 so that the side surface thereof is regulated and slides up and down.

Further, an inductor 14 is attached to a lower portion of the output transformer 13 with a gap between the output transformer 13 and the ERW tube 3. Upper guide rollers 15, 15 that roll in contact with each other are provided. Further, an inductor supporting frame 5 for integrally supporting these mechanisms.
As shown in FIG. 1, the lower part of the mounting base 17 is connected to a mounting base 17 via an emergency evacuation air cylinder 16, and the lower part of the mounting base 17 is connected to a height adjusting jack 18, and the mounting base 17 is supported by a support stand. Up and down along the guide rail 19 provided in 7,
An uneven load is prevented from being applied to the height adjusting jack 18.

In the above-mentioned heating apparatus, the pressure P of the cylinder 21 is set to be slightly smaller than the total weight W of the output transformer 13, the inductor 14, and the upper guide rollers 15, 15. In addition, by adjusting the height adjusting jack 18 and the height adjusting jack 11 according to the diameter of the ERW pipe 3, the center of rotation of the inductor 13 is made to coincide with the center of the ERW pipe 3.
In this state, the electric resistance welded tube 3 is conveyed onto the lower roller 2, an electric current is supplied to the inductor 14 through the output transformer 13, and the welded portion 4 of the electric resistance welded tube 3 conveyed below is heated by annealing. I do.

While the welded portion 4 of the electric resistance welded tube 3 is rotated left and right during conveyance, the position of the welded portion 4 is detected by a sensor (not shown), and the movable carriage 10 is moved in a circle as shown in FIG. By rotating along the arc-shaped guide 9, the inductor 14 follows the change in the position of the welded portion 4. In the case where the ERW pipe 3 has an undulation that is smaller than the swell of a prescribed size that is urgently retracted, or when the height adjustment is set to be smaller than the actual diameter of the ERW pipe 3, A force acts to lift the upper guide rollers 15, 15 in contact therewith. In this state, since the upper guide rollers 15, 15, the inductor 14, and the output transformer 13 are integrally connected, a force is applied to the ERW pipe 3 to push them upward.

However, since the pressure P of the cylinder 21 is set slightly smaller than the weight W of the output transformer 13, the inductor 14, and the upper guide rollers 15, 15, the ERW pipe 3
When the upper guide roller 15 is pushed up with a larger force than the WP, the rod of the cylinder 21 extends upward, and the upper and lower portions of the welded portion 4 of the ERW pipe 3 are raised. Movement can be absorbed.

Therefore, even if the ERW pipe 3 has a waviness smaller than the prescribed waviness for urgent retreat, or if the height adjustment of the inductor 14 is set smaller than the actual ERW pipe 3 diameter, Even if the upper guide roller 15 is pushed up due to undulation, the vertical movement is absorbed by the cylinder 21, so that the deformation of the ERW pipe 3 can be prevented, and the ERW pipe 3 can be prevented from deforming. Damage to the contact surface and wear of the upper guide roller 15 can be reduced.

[0020]

As described above, according to the present invention, in the case where there is a swell smaller than the prescribed swell for urgently retracting the ERW pipe, or the height adjustment of the inductor is made smaller than the actual ERW pipe diameter. Even when set to a small value, the weight applied to the ERW pipe is reduced to prevent deformation of the ERW pipe, to reduce the damage to the contact surface of the ERW pipe and the wear of the upper guide roller, and to increase the capacity of the heating device. Thus, an induction heating device that can be manufactured can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an induction heating device according to an embodiment of the present invention.

FIG. 2 is a side view showing the induction heating device of FIG. 1 with a part cut away.

FIG. 3 is a front view showing a state in which the inductor of FIG. 1 is rotated following a welded portion of the ERW pipe.

FIG. 4 is a partially cutaway front view of a conventional induction heating device.

FIG. 5 is a side view showing the induction heating device of FIG. 4 with a part cut away.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Conveying stand 2 Lower roller 3 ERW pipe 4 Welded part 5 Inductor support frame 7 Support stand 9 Arc guide 10 Moving trolley 11 Height adjustment jack 12 Output transformer mounting plate 13 Output transformer 14 Inductor 15 Upper guide Roller 16 Air cylinder for emergency evacuation 18 Jack for height adjustment 20 Guide frame 21 Cylinder 22 Sliding part

Claims (1)

[Claims] 1. An inductor support frame provided above an electric resistance welded tube to be conveyed, a movable truck rotating left and right on an arcuate guide attached to the frame, A guide frame supported on this via an adjusting jack, an output transformer mounting plate supported on the guide frame via a cylinder, and the guide frame is slidably penetrated through the mounting plate. An output transformer mounted below, and an inductor provided below and facing the ERW pipe below the output transformer, and an upper part of the ERW pipe mounted before and after the inductor. And an upper guide roller that rolls.