JPH11320121A - Welding device by high frequency induction heating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding device to be operated with a high frequency induction heating wherein a lowering of temperature due to blasting of an inert gas is prevented at a part to be welded and quality of welding/joining part is not deteriorated. SOLUTION: This is referred to a welding device being operated with a high frequency induction heating using a power source device 1 for a high frequency induction heating, a work 3 for high frequency heating and an inert gas generation device 5 such as a nitrogen or an argon gas. The device comprises an electromagnetic valve 7 installed between the work 3 for the high frequency heating and the inert gas generation device 5, a DC current detecting element 13 to detect a DC current of the power source device 1 for the high frequency induction heating, and an electromagnetic valve control circuit 20 to control an opening degree of the electromagnetic valve 7 depending on a size of an output signal from the DC current detecting element 13. Thereby, a flow rate of the inert gas being flowed into the part to be welded is controlled to be the best one, so that lowering of temperature due to a blasting of the excessive inert gas more than necessity can be prevented at the part to be welded, and deterioration of welding jointing part quality is also prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency induction heating apparatus, a high-frequency heating work, and a welding apparatus by high-frequency induction heating using an inert gas in order to maintain a weld in a non-oxidizing atmosphere.

[0002]

2. Description of the Related Art A welding method using high-frequency induction heating using a high-frequency induction heating device and a high-frequency heating work is widely used for welding steel pipes, reinforcing bars, and the like. However, in the welding by this welding method, there is a possibility that the quality generated in the welded / joined portion may be deteriorated by an oxide generated by oxygen in the atmosphere. As a countermeasure, in order to prevent the oxidation of the joint of the workpiece, the welding has been attempted to be shielded by an inert gas such as argon gas or nitrogen gas at the time of welding.

FIG. 8 is a configuration diagram of a conventional welding apparatus using high-frequency induction heating. In the figure, 1 is a high-frequency induction heating device, 2 is a commercial power supply, 3 is a high-frequency heating work, 4 is a manual valve, and 5 is an inert gas generating device such as a cylinder. The high-frequency induction heating device 1 includes a converter circuit 10, a smoothing capacitor 11, and an inverter circuit 12. Since the high-frequency induction heating device 1 and the high-frequency heating work 3 are general devices, detailed description thereof will be omitted.

In the welding operation using the high-frequency induction heating apparatus 1 described above, an argon gas or a nitrogen gas is sent from the inert gas generator 5 to the high-frequency heating work 3 via the manual valve 4 and the welded portion including the welded portion is sent. While the argon gas or the nitrogen gas is blown in the vicinity, the high frequency induction current flowing through the heating coil of the high frequency heating work 3 connected to the output of the high frequency induction heating device 1 melts the portions to be joined and melt-bonds each other. It is performed by

FIG. 9 shows an example of an operation pattern of a welding operation by the high-frequency induction heating apparatus 1 using an inert gas. That is, in the welding operation, an inert gas is first generated, and the welded part is set to a shielding gas atmosphere by the inert gas.
To heat the welded portion. The end of the welding operation is performed by outputting a heating-off signal B and then stopping the inert gas. Thus, the degree of oxidation can be reduced by setting the part to be welded to a shield gas atmosphere during welding.

[0006]

However, in the above-described welding method, since the welded portion and the welded portion are set in a shield gas atmosphere, the welded portion is cooled by the inert gas to lower the temperature, and the predetermined welding is performed. There was a problem that the temperature could not be obtained and the quality of the joint was adversely affected.

[0007] This is because the greater the amount of the inert gas blown, the more the oxidation of the joint can be prevented. In order to obtain a predetermined joining temperature, a vicious cycle occurs in which additional heating is required.

[0008] For example, a case where the thickness sizes of the reinforcing bars are different will be described. An operator adjusts the inflow amount of the inert gas by the manual valve 4 according to the thickness of the reinforcing bar, and performs the fusion welding as the optimum welding condition. Therefore, it is necessary to adjust the inert gas every time the rebar size is different, and there is a possibility that the quality of the welded portion may be degraded due to an erroneous adjustment of the manual valve 4 by an operator.

The present invention (corresponding to claims 1 to 7) provides:
In view of the above circumstances, an object of the present invention is to provide a welding device that uses a high-frequency induction heating that prevents a decrease in the temperature of a welded portion due to blowing of an inert gas and does not lower the quality of a welded / joined portion. .

[0010]

In order to achieve the above object, a first aspect of the present invention is to provide a high-frequency induction heating power supply, a high-frequency heating work, and an inert gas such as nitrogen or argon gas. A high-frequency induction heating welding device using an inert gas generating device, a solenoid valve provided between the high-frequency heating work and the inert gas generating device, and a direct current of the high-frequency induction heating power supply device. And a solenoid valve control circuit that controls the opening of the solenoid valve according to the magnitude of the output signal of the DC current detection element.

According to a second aspect of the present invention, high-frequency induction heating using a high-frequency induction heating power supply, a high-frequency heating work, and an inert gas generator for generating an inert gas such as nitrogen or argon gas. In a welding apparatus, a solenoid valve provided between the high-frequency heating work and the inert gas generator, a DC current detecting element for detecting a DC current of the high-frequency induction heating power supply, and a DC for detecting a DC voltage. A voltage detection element, and an electromagnetic valve control circuit that controls an opening degree of the electromagnetic valve by a magnitude of a signal obtained by multiplying an output signal of the DC current detection element and an output signal of the DC voltage detection element. It is characterized by.

A third aspect of the present invention is a high-frequency induction heating using a high-frequency induction heating power supply device, a high-frequency heating work, and an inert gas generating device for generating an inert gas such as nitrogen or argon gas. In the welding apparatus, an electromagnetic valve provided between the high-frequency heating work and the inert gas generator, an AC current detecting element for detecting an AC current input to the high-frequency induction heating power supply, and the AC And a solenoid valve control circuit for controlling the opening of the solenoid valve according to the magnitude of the output signal of the current detecting element.

According to a fourth aspect of the present invention, high-frequency induction heating using a high-frequency induction heating power supply, a high-frequency heating work, and an inert gas generator for generating an inert gas such as nitrogen or argon gas. In the welding apparatus, an electromagnetic valve provided between the high-frequency heating work and the inert gas generator and an AC current detecting element for detecting an AC current input to the high-frequency induction heating power supply are input. An AC voltage detecting element for detecting an AC voltage, and an electromagnetic valve control circuit for controlling an opening degree of the electromagnetic valve by a magnitude of a signal obtained by multiplying an output signal of the AC current detecting element and an output signal of the AC voltage detecting element. And characterized in that:

According to a fifth aspect of the present invention, high-frequency induction heating using a high-frequency induction heating power supply, a high-frequency heating work, and an inert gas generator for generating an inert gas such as nitrogen or argon gas. In the welding device, a solenoid valve provided between the high-frequency heating work and the inert gas generator, a high-frequency AC current detection element that detects a high-frequency AC current output from the high-frequency induction heating power supply device, And a solenoid valve control circuit for controlling the opening of the solenoid valve according to the magnitude of the output signal of the high-frequency AC current detection element.

According to a sixth aspect of the present invention, in the welding apparatus according to the first to fifth aspects, the solenoid valve control circuit for controlling the opening of the solenoid valve is proportional to the magnitude of the detection signal. And controlling the opening of the solenoid valve.

According to a seventh aspect of the present invention, in the welding apparatus according to the first to fifth aspects of the present invention, the electromagnetic valve control circuit for controlling the opening of the electromagnetic valve includes a stepped switch according to the magnitude of the detection signal. It is characterized in that the opening of the solenoid valve is controlled.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a welding apparatus using high-frequency induction heating according to a first embodiment (corresponding to claim 1) of the present invention.

In this figure, the present embodiment is different from the conventional welding apparatus using high-frequency induction heating shown in FIG. 8 in that a solenoid valve 7 provided between a high-frequency heating work 3 and an inert gas generator 5 includes A direct current detecting element 13 for detecting a direct current of the power supply device 1 for induction heating;
3 is that an electromagnetic valve control circuit 20 for controlling the opening of the electromagnetic valve 7 in accordance with the magnitude of the output signal is provided, and the other components are the same. Will be explained.

Next, the normal operation of this embodiment will be described. In welding work of steel pipes and rebars, an argon gas or a nitrogen gas is sent from an inert gas generator 5 such as a cylinder to the high frequency heating work 3 via the electromagnetic valve 7 and argon is supplied to the vicinity of the welded portion including the welded portion. While the gas or nitrogen gas is being blown, the parts to be joined are melted and joined together by a high-frequency induction current flowing through the heating coil of the high-frequency heating work 3 connected to the output of the high-frequency induction heating device 1.

Since the high-frequency induction heating device 1 has a general configuration, detailed description of its operation is omitted. However, the direct current of the high-frequency induction heating device 1 is proportional to the electric power required for fusion-coupling. The DC current detecting element 13
By detecting the DC current of the high-frequency induction heating device 1, it is possible to detect the power required for the welding operation. Also, by inputting the signal detected by the DC current detecting element 13 to the solenoid valve control circuit 20 for controlling the opening of the solenoid valve 7, the solenoid valve 7 is controlled in proportion to the power required for welding work. It is possible to control the opening.

According to this embodiment, the electric power necessary for fusion-bonding the steel pipe, the reinforcing steel, and the like is detected, and the vicinity of the welded portion including the welded portion is detected at the opening of the solenoid valve proportional to the detected electric power. Since an argon gas or a nitrogen gas can be sprayed on the surface, a decrease in the temperature of the portion to be welded due to the spraying of the inert gas more than necessary can be prevented, and a deterioration in the quality of the welded / joined portion can be prevented.

FIG. 2 is a block diagram of a welding apparatus using high frequency induction heating according to a second embodiment (corresponding to claim 2) of the present invention.
In the figure, the present embodiment is different from the first embodiment in FIG. 1 in that a DC voltage detecting element 14 for detecting the DC voltage of the high-frequency induction heating power supply 1 and an output signal of the DC voltage detecting element 14 This is the point that an electromagnetic valve control circuit 20 for controlling the opening of the electromagnetic valve 7 according to the magnitude of the signal multiplied by the output signal of the current detecting element 13 is provided. The components will be described with the same reference numerals.

Next, the normal operation of this embodiment will be described. In the present embodiment, similarly to the first embodiment, the DC power of the high-frequency induction heating device 1 is proportional to the power required for fusion-bonding the steel pipe, the reinforcing bar, and the like.
By detecting the DC power of the high-frequency induction heating device 1 with the DC voltage detector 3 and the DC voltage detecting element 14, it is possible to detect the power required for the welding operation. Therefore, by inputting the signals detected by the DC current detecting element 13 and the DC voltage detecting element 14 to the solenoid valve control circuit 20 for controlling the opening of the solenoid valve 7, the signals are proportional to the power required for the welding work. Thus, the opening of the solenoid valve 7 can be controlled.

The present embodiment is effective when the voltage of the commercial power supply 2 fluctuates, detects the electric power necessary for fusion-bonding the steel pipe and the reinforcing bar, etc., and sets the opening in proportion to the detected electric power. In, since argon gas or nitrogen gas can be sprayed in the vicinity of the welded portion including the welded portion,
It is possible to prevent the temperature of the welded portion from lowering due to the blowing of the inert gas more than necessary, and to prevent the deterioration of the quality of the welded / joined portion.

FIG. 3 is a block diagram of a welding apparatus using high frequency induction heating according to a third embodiment (corresponding to claim 3) of the present invention.
In the drawing, this embodiment is different from the first embodiment in FIG. 1 in that an AC current detection element 15 for detecting an AC current input to the high-frequency induction heating power supply device 1 is provided instead of the DC current detection element 13. Is that an electromagnetic valve control circuit 20 for controlling the opening of the electromagnetic valve 7 in accordance with the magnitude of the output signal of the AC current detecting element 15 is provided, and the other components are the same. Will be described with the same reference numerals.

Next, the normal operation of this embodiment will be described. In this embodiment, similarly to the first and second embodiments, the alternating current input to the high-frequency induction heating device 1 is proportional to the electric power required for fusion-bonding the steel pipe, the reinforcing steel, and the like. Therefore, it is possible to detect the electric power required for the welding work by detecting the alternating current input to the high-frequency induction heating device 1 with the alternating current detecting element 15. Also, by inputting a signal detected by the AC current detecting element 15 to the solenoid valve control circuit 20 for controlling the opening of the solenoid valve 7, the opening of the solenoid valve 7 is proportional to the power required for welding work. It is possible to control the degree.

According to the present embodiment, the electric power necessary for fusion-bonding the steel pipe, the reinforcing steel, and the like is detected, and the argon gas or the gas near the welded part including the welded part is opened at an opening proportional to the detected electric power. Since nitrogen gas can be sprayed,
It is possible to prevent the temperature of the welded portion from lowering due to the blowing of the inert gas more than necessary, and to prevent the deterioration of the quality of the welded / joined portion.

FIG. 4 is a block diagram of a welding apparatus using high-frequency induction heating according to a fourth embodiment of the present invention (corresponding to claim 4).
In this figure, the present embodiment is different from the first embodiment in FIG. 1 in that an AC current detecting element for detecting an AC current and an AC voltage input to the high-frequency induction heating power supply device 1 instead of the DC current detecting element 13 is provided. 15 and an AC voltage detecting element 16 are provided.
6 in that an electromagnetic valve control circuit 20 for controlling the opening of the electromagnetic valve 7 is provided according to the magnitude of the signal obtained by multiplying each output signal of the second embodiment, and the other configuration is the same. Will be described with the same reference numerals.

Next, the normal operation of this embodiment will be described. In this embodiment, as in the first to third embodiments, the AC power input to the high-frequency induction heating device 1 is proportional to the power required to melt-bond the steel pipe, the reinforcing steel, and the like. Therefore, by detecting the AC power input to the high-frequency induction heating device 1 with the AC current detection element 15 and the AC voltage detection element 16, it is possible to detect the power required for the welding operation. By inputting the signals detected by the AC current detecting element 15 and the AC voltage detecting element 16 to the solenoid valve control circuit 20 for controlling the opening of the solenoid valve 7,
It is possible to control the opening of the solenoid valve 7 in proportion to the electric power required for the welding operation.

According to the present embodiment, the electric power required for fusion-bonding the steel pipe, the reinforcing steel, and the like is detected, and argon gas or argon gas is supplied near the welded portion including the welded portion at an opening proportional to the detected electric power. Since nitrogen gas can be sprayed,
It is possible to prevent the temperature of the welded portion from lowering due to the blowing of the inert gas more than necessary, and to prevent the deterioration of the quality of the welded / joined portion. This embodiment is particularly effective when the voltage of the commercial power supply 2 fluctuates.

FIG. 5 is a block diagram of a welding apparatus using high-frequency induction heating according to a fifth embodiment (corresponding to claim 5) of the present invention.
In the drawing, this embodiment differs from the first embodiment in FIG. 1 in that a high-frequency AC current detecting element 17 for detecting a high-frequency AC current output from the high-frequency induction heating power supply device 1 instead of the DC current detecting element 13 is provided. And an electromagnetic valve control circuit 20 for controlling the opening of the electromagnetic valve 7 in accordance with the magnitude of the output signal of the high-frequency AC current detecting element 17 is provided. The same components will be described with the same reference numerals.

Next, the normal operation of this embodiment will be described. In this embodiment, similarly to the first to fourth embodiments, the alternating current output from the high-frequency induction heating device 1 is proportional to the electric power required for fusion-bonding the steel pipe, the reinforcing steel, and the like. Therefore, by detecting the high-frequency AC current output from the high-frequency induction heating device 1 with the high-frequency AC current detection element 17, it is possible to detect the power required for the welding work. By inputting a signal detected by the high-frequency AC current detecting element 17 to an electromagnetic valve control circuit 20 for controlling the opening of the solenoid valve 7, the opening of the solenoid valve 7 is proportional to the power required for welding work. Can be controlled.

According to the present embodiment, the electric power necessary for melting and joining the steel pipe and the reinforcing steel is detected, and the argon gas is supplied to the vicinity of the welded portion including the welded portion at an opening proportional to the detected electric power. Alternatively, since nitrogen gas can be sprayed, the temperature of the welded portion can be prevented from lowering due to the spraying of the inert gas more than necessary, and the deterioration of the quality of the welded / joined portion can be prevented.

FIG. 6 is a characteristic diagram showing input / output characteristics of a solenoid valve control circuit according to a sixth embodiment (corresponding to claim 6) of the present invention. In the figure, the welding apparatus to which the present embodiment is applied is the welding apparatus using the high-frequency induction heating of the above-described first to fifth embodiments, and the solenoid valve control circuit 20 detects the detection signal of each of the above-mentioned embodiments. The control is performed in proportion to the size and in proportion to the opening of the solenoid valve 7.

Next, the normal operation of this embodiment will be described. The solenoid valve control circuit 20 of the present embodiment includes the first
The current and power detection signals of the welding apparatus using high-frequency induction heating according to the fifth to fifth embodiments are input. Since these detection signals are amplified into signals that can excite the coil of the solenoid valve 7, the opening of the solenoid valve 7 is controlled in proportion to the magnitude of the current and power detection signals described in the above embodiments. Can be.

According to the present embodiment, the electric power necessary for melting and joining the steel pipe, the reinforcing steel, and the like is detected, and argon is supplied to the vicinity of the welded portion including the welded portion at an opening proportional to the detected electric power. Since the gas or the nitrogen gas can be blown, it is possible to prevent the temperature of the welded portion from lowering due to the blowing of the inert gas more than necessary, and to prevent the deterioration of the quality of the welded / joined portion.

FIG. 7 is a characteristic diagram showing input / output characteristics of a solenoid valve control circuit according to a seventh embodiment (corresponding to claim 7) of the present invention. In the figure, the welding apparatus to which the present embodiment is applied is the welding apparatus using the high-frequency induction heating of the above-described first to fifth embodiments, and the solenoid valve control circuit 20 detects the detection signal of each of the above-mentioned embodiments. The control is performed in proportion to the size and in proportion to the opening of the solenoid valve 7.

Next, the normal operation of this embodiment will be described. The solenoid valve control circuit 20 of the present embodiment includes the first
The current and power detection signals of the welding apparatus using high-frequency induction heating according to the fifth to fifth embodiments are input. These detection signals are amplified to signals that can excite the coil of the solenoid valve 7. The amplified signal is compared by two types of setters having different set levels, and is amplified to a signal that can excite the coil of the solenoid valve 7. Therefore, the opening of the solenoid valve 7 can be controlled stepwise by the magnitude of the current and power detection signals described in the above embodiments.

According to the present embodiment, the electric power required for fusion-bonding the steel pipe and the rebar is detected, and the argon gas is supplied to the vicinity of the welded portion including the welded portion at an opening proportional to the detected electric power. Alternatively, since a nitrogen gas can be blown, it is possible to prevent the temperature of the fusible portion from lowering due to the spraying of the inert gas more than necessary, and to obtain a welding apparatus in which the quality of the welded / joined portion does not deteriorate. This embodiment is particularly effective for a welding operation in which the number of parts to be welded is limited to some extent.

[0040]

As described above, the present invention (Claim 1)
According to claim 7, since the opening of the solenoid valve can be automatically controlled based on the magnitude of the current and the power signal detected from the high-frequency induction heating power supply device, the inert gas flowing into the welded portion can be automatically controlled. Can automatically control the flow rate. Therefore, since the optimum amount of the inert gas is introduced, the temperature of the welded portion can be prevented from lowering due to the unnecessary spraying of the inert gas, and the quality of the welded / joined portion can be prevented from lowering.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a fifth embodiment of the present invention.

FIG. 6 is a characteristic diagram showing a relationship between a DC current which is an input / output of a solenoid valve control circuit and a solenoid valve opening according to a sixth embodiment of the present invention.

FIG. 7 is a characteristic diagram showing a relationship between a DC current which is an input / output of a solenoid valve control circuit and a solenoid valve opening according to a seventh embodiment of the present invention.

FIG. 8 is a configuration diagram of a conventional high-frequency induction heating device.

FIG. 9 is a diagram showing an example of an operation pattern of a welding operation using a conventional high-frequency induction heating device and an inert gas.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... High frequency induction heating power supply device, 2 ... Commercial power supply, 3 ... High frequency heating work, 4 ... Manual valve, 5 ... Inert gas generator, 7 ... Electromagnetic valve, 10 ... Converter circuit, 11 ... Smoothing capacitor, 12: Inverter circuit, 13: DC current detecting element, 14: DC voltage detecting element, 15: AC current detecting element, 16: AC voltage detecting element, 17: High frequency AC current detecting element, 20: Solenoid valve control circuit.

Claims (7)

[Claims] 1. A welding apparatus for high-frequency induction heating using a power supply for high-frequency induction heating, a work for high-frequency heating, and an inert gas generator for generating an inert gas such as nitrogen or argon gas. An electromagnetic valve provided between the heating work and the inert gas generator, a DC current detecting element for detecting a DC current of the high-frequency induction heating power supply, and a magnitude of an output signal of the DC current detecting element And a solenoid valve control circuit for controlling the opening of the solenoid valve. 2. A welding apparatus for high-frequency induction heating using a high-frequency induction heating power supply, a high-frequency heating work, and an inert gas generator for generating an inert gas such as nitrogen or argon gas. A solenoid valve provided between the heating work and the inert gas generator, a DC current detection element for detecting a DC current of the power supply for high-frequency induction heating, and a DC voltage detection element for detecting a DC voltage,
An electromagnetic valve control circuit for controlling an opening of the electromagnetic valve by a magnitude of a signal obtained by multiplying an output signal of the DC current detecting element and an output signal of the DC voltage detecting element. Welding equipment by induction heating. 3. A welding apparatus for high-frequency induction heating using a high-frequency induction heating power supply, a high-frequency heating work, and an inert gas generator for generating an inert gas such as nitrogen or argon gas. An electromagnetic valve provided between the heating work and the inert gas generator, an AC current detection element for detecting an AC current input to the high-frequency induction heating power supply, and an output signal of the AC current detection element And a solenoid valve control circuit for controlling the opening of the solenoid valve according to the size of the welding device. 4. A welding apparatus by high-frequency induction heating using a high-frequency induction heating power supply, a high-frequency heating work, and an inert gas generator for generating an inert gas such as nitrogen or argon gas. An electromagnetic valve provided between the heating work and the inert gas generator, an AC current detecting element for detecting an AC current input to the high-frequency induction heating power supply device, and an AC for detecting an AC voltage input A voltage detection element, and an electromagnetic valve control circuit that controls an opening degree of the electromagnetic valve by a magnitude of a signal obtained by multiplying an output signal of the AC current detection element and an output signal of the AC voltage detection element. Welding equipment by high frequency induction heating. 5. A welding apparatus for high-frequency induction heating using a high-frequency induction heating power supply, a high-frequency heating work, and an inert gas generator for generating an inert gas such as nitrogen or argon gas. An electromagnetic valve provided between the heating work and the inert gas generator, a high-frequency AC current detection element for detecting a high-frequency AC current output from the high-frequency induction heating power supply, and the high-frequency AC current detection element And a solenoid valve control circuit for controlling the opening of the solenoid valve according to the magnitude of the output signal of the welding device. 6. The welding apparatus according to claim 1, wherein the solenoid valve control circuit for controlling the opening of the solenoid valve is configured to open the solenoid valve in proportion to the magnitude of the detection signal. A welding apparatus using high-frequency induction heating, characterized in that the degree is controlled. 7. The welding apparatus according to claim 1, wherein the solenoid valve control circuit for controlling the opening of the solenoid valve is configured to open and close the solenoid valve stepwise according to the magnitude of the detection signal. A welding apparatus using high-frequency induction heating, characterized in that the degree is controlled.