JPH11170081A - Stress relief heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to rapidly heat up the parts requiring heating of a material to be heated up to a prescribed temp and to automate heating work. SOLUTION: An amplifier transformer 12 and a heating coil 13 are mounted on a traveling truck 11 of the stress relief heater 10. This traveling truck 11 has a drive wheels 15 and auxiliary wheels and are travelable in an arrow 18 direction along guide rails 17 during the heating work. A ferrite core 22 is arranged in order to concentrate the magnetic fluxes generated by the heating coil 13 to the parts requiring heating and a surface treating material 21 is mounted to protect the heating coil 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strain relief heating device used in a process for removing a welded portion in a process of manufacturing a metal structure such as a ship.

[0002]

2. Description of the Related Art Steel structures such as ships often have parts that can be assembled by welding steel plates. However, since the welded parts are distorted, the welded parts are usually heated after welding. Accordingly, an operation of removing distortion has been performed.

In the conventional strain relief operation, a method has been adopted in which an operator heats the gas torch while moving it along the welded portion while holding the gas torch in his hand. However, the method using gas heating is likely to cause temperature unevenness due to surface heating, and also requires a high degree of skill in the work, and in recent years when the shortage of skilled workers has become remarkable, adoption has decreased, and instead, Heating by an induction heating device is performed.

[0004] As a conventional high-frequency induction heating apparatus, for example, there is one as shown in FIG. 8. A high-frequency current supplied from a heating power supply 50 is supplied to a box-shaped heating coil 51 to generate a high-frequency alternating magnetic flux. The steel plate 52 to be heated
The steel plate 52 itself is heated by Joule heat generated by the eddy current generated in the sheet.

In an actual heating operation, a heating coil 51 is mounted on a welded portion 53 of a steel plate 52 and a switch 54 is provided.
Is turned on and the heating coil 51 is energized to perform heating for a predetermined time, and then the switch 55 is operated to stop energization. Thereafter, the heating coil 51 is moved by a predetermined distance along the welding portion 53 and stopped. , Switch ON again
The operation of heating for a predetermined time is repeated many times.

That is, an operator 56 grasps the hand pushing bar 57 by hand, intermittently moves the heating coil 51 along the welded portion 53 by a predetermined distance, and switches the switches 54 and 5.
By repeating the ON / OFF operation of No. 5, the distortion removing heating operation is performed.

[0007]

In the case of the conventional high-frequency induction heating apparatus, as shown in FIG. 8, the movement of the heating coil 51 and the ON / OFF operation of the heating coil 51 are all performed manually by an operator 56. Work efficiency is poor.

Further, in the conventional high-frequency induction heating apparatus, the current value which can be supplied to the heating coil 51 is a small value of about 80 A to 100 A. It takes a long time to work.

Further, since the area which can be heated is substantially determined by the size of the heating coil 51, when it is necessary to change the heating area due to a difference in the thickness of the welded steel material, it is difficult to quickly respond.

[0010] Therefore, an object of the present invention is to provide a distortion removing heating device that can raise the temperature of an object to be heated in a short time and can automate the heating operation. .

[0011]

In order to solve the above-mentioned problems, a distortion removing and heating apparatus according to the present invention comprises an amplifying transformer for amplifying and outputting an input high-frequency current, and an amplifying transformer provided by the high-frequency current supplied from the amplifying transformer. It is characterized by comprising an induction heating coil for generating a magnetic field, and running means for moving the amplification transformer and the induction heating coil.

With such a configuration, a high-frequency current having a large current value amplified by the amplification transformer can be supplied to the induction heating coil. An eddy current is generated, and the object to be heated can be heated to a predetermined temperature in a short time by Joule heat accompanying the eddy current. In this case, since the amplifying transformer and the induction heating coil can be moved by the traveling means, the heating operation can be automated by traveling along the portion to be heated, and the operation efficiency can be improved. .

In the distortion removing heating apparatus according to the present invention, the induction heating coil has a structure detachable from the amplification transformer, so that when the heating area needs to be changed, the induction heating coil having a different size or shape is required. Replacement can be easily performed. In addition, when the induction heating coil is deteriorated or damaged, replacement work is easy.

Further, in the distortion removing heating device of the present invention,
By making the shape of the induction heating coil U-shaped, the heating region in the longitudinal direction can be expanded, and by making it circular, a wide range in the longitudinal direction and the width direction can be heated. Heating work can be performed, which can contribute to improvement of work efficiency.

On the other hand, in the strain relief heating device of the present invention, the frequency of the output current of the amplification transformer is set to 1 kHz to 90 kHz.
It is desirable to be set to kHz. Output current frequency is 1k
When the frequency is lower than Hz, it is necessary to increase the size of the amplifying transformer. Therefore, the shape and weight of the device are increased, so that the portability is deteriorated. On the other hand, as the frequency of the output current of the amplification transformer increases, the temperature rising region of the object to be heated tends to be shallower. Therefore, the frequency of the output current of the amplification transformer is 1 kHz to 90 kHz.
z is the optimal range.

Further, in the distortion removing heating apparatus according to the present invention, by setting the output current of the amplification transformer to 1000 A to 6000 A, a large current can be supplied to the induction heating coil. The temperature can be raised over time.

The output current of the amplifying transformer is 1000
If it is smaller than A, a long heating time is required, so that the energy loss due to heat dissipation increases, and the temperature rises to an unnecessary part of the object to be heated by heat conduction. Therefore, while the surface portion of the object to be heated is intensively heated, insufficient heating in the depth direction is likely to occur. Therefore, the optimum output current of the amplifying transformer is 1000A to 6000A.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing the strain relief heating device of the first embodiment, FIG. 2 is a side view thereof, FIG. 3 is a rear view thereof, and FIG. 4 is a partially enlarged view of FIG.

In the strain relief heating apparatus 10 of the present embodiment, an amplifying transformer 12 and an induction heating coil 13 are mounted on a traveling vehicle 11, and the traveling vehicle 11 is driven by a motor 14 by driving wheels 15 and auxiliary wheels 16. During the heating operation, the vehicle can travel in the direction of the arrow 18 along the guide rail 17. Further, the guide rail 17 is provided with a cable guide 19 for holding a power cable, a cooling water hose, and the like connected to the strain relief heating device 10.

Here, the amplifying transformer 12 can amplify the input high-frequency current and output a high-frequency current having a frequency of 1 kHz to 90 kHz and a current of 1000 A to 6000 A. The induction heating coil is supplied by the high-frequency current supplied from the amplifying transformer 12. 13 generates an alternating magnetic field.

In this case, a ferrite core 22 is arranged to concentrate the magnetic flux generated by the induction heating coil 13 on a portion requiring heating, and a surface treatment material 21 is provided to protect the induction heating coil 13.

With this configuration, a high-frequency current having a large current value amplified by the amplification transformer 12 can be supplied to the induction heating coil 13. An eddy current is generated, and the Joule heat accompanying the eddy current can raise the temperature of the welded portion 20w of the steel plate 20 to a required temperature in a short time. In addition, the traveling vehicle 11 is driven by the motor 14 to guide the welding portion 2 while being guided by the guide rail 17.
Since the vehicle can travel in the direction of arrow 18 along 0w, the strain relief heating operation can be performed automatically.

Further, the strain relief heating device 10 of the present embodiment
In this case, since the induction heating coil 13 is detachable from the output terminal of the amplification transformer 12, when the heating area needs to be changed, the induction heating coil 13 can be easily replaced with an induction heating coil having a different size or shape. . In addition, when the induction heating coil 13 is deteriorated or damaged, replacement work is also easy.

Further, the distortion removing heating device 1 of the present embodiment
In the case of 0, the shape of the induction heating coil 13 is U-shaped, so that a large heating area in the longitudinal direction can be secured in the welded portion 20w, and the working efficiency is high.

In the conventional strain relief heating operation, a method of heating both sides of the welded portion 20w in the form of footprints instead of heating the entire welded portion 20w has been adopted. It has been found that even when the entire welding portion 20w is heated while the distortion removing heating device 10 is moved along the welding portion 20w, the same distortion removing effect as in the related art can be obtained, and there is no problem.

Here, the performance of the strain relief heating device 10 is as follows.
A description will be given in comparison with a conventional strain relief heating device. Using a strain relief heating device 10 and a conventional strain relief heating device, a steel plate having a thickness of 6 mm and
The time required to raise the temperature to
mm, the conventional strain relief heating device required 55 seconds, whereas the strain relief heating device 10 required 19 seconds. In the case of a plate thickness of 10 mm, the conventional strain relief heating device is 3 mm.
Minutes and 53 seconds, the strain relief heating device 10
4 seconds. In this case, the strain relief heating device 10
, The output current of the amplification transformer 12 is 1000 A,
The heating operation was performed at a frequency of 25 kHz.

FIG. 5 is a graph of these data.
It is. FIG. 5 shows that the strain relief heating device 10 can raise the temperature to 700 ° C. in a shorter time than the conventional strain relief heating device in both cases of the plate thickness of 6 mm and 10 mm. The effect of shortening the heating time by the strain relief heating device 10 is more remarkable as the thickness of the steel sheet increases.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a plan view showing a strain relief heating device according to the second embodiment.

The distortion removing heating device 30 of the present embodiment comprises an amplifying transformer 3 for amplifying and outputting an input high-frequency current.
1, an induction heating coil 32 that generates an alternating magnetic field by a high-frequency current supplied from the amplification transformer 31, a traveling vehicle 33 equipped with the amplification transformer 31 and the induction heating coil 32, and the traveling vehicle 33 along the guide rail 37. And a driving device 35 for moving in the direction of the arrow 36.

Similar to the strain relief heating device 10 shown in FIGS. 1 to 3, the strain relief heating device 30 also controls the high frequency amplified by the amplification transformer 31 while moving the traveling carriage 33 in the direction of the arrow 36 along the guide rail 37. Induction heating coil 3
2 to generate an alternating magnetic field, so that the work of removing the distortion of the welded portion 34w of the steel plate 34 can be automatically performed. In the case of the strain relief heating device 30, the induction heating coil 32
Is circular, even if the width of the welded portion 34w of the steel plate 34 is large, this range can be uniformly heated.

Therefore, the strain relief heating device 30 is suitable for performing the strain relief heating operation when the steel plate 34 is thick and the width of the welded portion 34 w is wide, and the ferrite cores ( By arranging the heating regions (not shown), the heating regions can be arranged in a plurality of rows.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a side view showing a strain relief heating device according to the third embodiment.

The distortion removing and heating device 40 of the present embodiment comprises an amplifying transformer 4 for amplifying and outputting an input high-frequency current.
1, an induction heating coil 42 for generating an alternating magnetic field by a high-frequency current supplied from the amplification transformer 41, and a traveling vehicle 43 on which the amplification transformer 41 and the induction heating coil 42 are mounted. Can be moved to

The strain relief heating device 40 is similar to the strain relief heating device 10 shown in FIGS.
While moving in the direction, the high frequency current amplified by the amplification transformer 41 is supplied to the induction heating coil 42 to generate an alternating magnetic field, so that the work for removing the distortion of the welded portion of the steel plate 44 can be automatically performed.

In the case of the strain relief heating device 40, since the vertically occupied space is reduced by adopting the vertically long amplification transformer 41, it is suitable for performing strain relief heating work in a narrow place.

In the first to third embodiments, the strain relief heating operation in the case where the welded portions 20w and 34w are linear has been described. However, the present invention is not limited to these. If a curved guide rail is used instead of 37, it is possible to cope with a case where the welded portion is curved.

The strain relief heating devices 10, 30, 40
Are suitable for strain relief heating work when the object to be heated is in a horizontal state, but the present invention is not limited to these. By providing a guide rail or the like for traveling while holding in a state, it is possible to perform a heating operation on a vertical surface or an inclined surface.

[0038]

According to the present invention, the following effects can be obtained.

(1) An amplifying transformer for amplifying and outputting an input high-frequency current, an induction heating coil for generating an alternating magnetic field by the high-frequency current supplied from the amplification transformer, and traveling for moving the amplification transformer and the induction heating coil. Means, a high-frequency current having a large current value amplified by the amplification transformer can be supplied to the induction heating coil, so that the object to be heated can be heated to a predetermined temperature in a short time, Since the amplification transformer and the induction heating coil can be moved by the means, the heating operation can be automated and the operation efficiency can be improved.

(2) By adopting a structure in which the induction heating coil can be attached to and detached from the amplification transformer, it is possible to easily replace the induction heating coil with a different size or shape when the heating area needs to be changed. Can be. In addition, when the induction heating coil is deteriorated or damaged, replacement work is easy.

(3) By making the shape of the induction heating coil U-shaped, a wide heating area in the longitudinal direction can be secured, and by making it circular, a wide range in the longitudinal direction and the width direction can be heated. Therefore, the heating operation according to the situation can be performed, which can contribute to the improvement of the operation efficiency.

(4) By setting the frequency of the output current of the amplifying transformer to 1 kHz to 90 kHz, the size of the amplifying transformer can be reduced, the temperature rising region can be optimized, and the power loss of the connection cable can be suppressed. Can be.

(5) The output current of the amplifying transformer is set to 1000
By setting the current to A to 6000 A, a large current can be supplied to the induction heating coil, so that the portion of the object to be heated which needs to be heated can be heated in a short time.

[Brief description of the drawings]

FIG. 1 is a plan view showing a distortion removal heating device according to a first embodiment.

FIG. 2 is a side view of the strain relief heating device of FIG.

FIG. 3 is a rear view of the strain relief heating device of FIG. 1;

FIG. 4 is a partially enlarged view of FIG. 3;

FIG. 5 is a graph comparing heating times of the strain relief heating device of the first embodiment and a conventional strain relief heating device.

FIG. 6 is a plan view showing a strain relief heating device according to a second embodiment.

FIG. 7 is a side view showing a strain relief heating device according to a third embodiment.

FIG. 8 is a perspective view showing a conventional strain relief heating device.

[Explanation of symbols]

 10, 30, 40 Strain relief heating device 11, 33, 43 Traveling trolley 12, 31, 41 Amplifying transformer 13, 32, 42 Induction heating coil 14 Motor 15 Drive wheel 16 Auxiliary wheel 17, 37 Guide rail 18, 36, 44 Arrow Wire 19 Cable guide 20, 34, 44 Steel plate 20w, 34w Welded part 21 Surface treatment material 22 Ferrite core 35 Drive unit

Claims (5)

[Claims] 1. An amplifying transformer for amplifying and outputting an input high-frequency current, an induction heating coil for generating an alternating magnetic field by the high-frequency current supplied from the amplification transformer, and moving the high-frequency amplification transformer and the induction heating coil And a running means for causing the strain to be removed. 2. The distortion removing heating device according to claim 1, wherein the induction heating coil is detachable from the amplification transformer. 3. The strain relief heating device according to claim 1, wherein the shape of the induction heating coil is U-shaped or circular. 4. The strain relief heating device according to claim 1, wherein the frequency of the output current of the amplification transformer is 1 kHz to 90 kHz. 5. The output current of said amplifying transformer is 1000
The strain relief heating device according to claim 1, wherein the heating device has a temperature of A to 6000 A.