JP2023012241A - Welding device and welding method - Google Patents

Abstract

To provide a welding device which can control heat gain to a base material more precisely by using laser-arc hybrid welding method.SOLUTION: A welding device welds a base material by using laser welding and arc welding. The welding device includes: an arc welding torch which generates an arc between itself and a joint part of the base material; a laser welding torch which radiates a laser to the joint part; a measuring part which measures a state of the laser welding using the laser welding torch; and a control unit which controls arc welding using the arc welding torch based on a measurement result of the measuring part.SELECTED DRAWING: Figure 1

Description

The present invention relates to welding equipment and welding methods.

Patent Literature 1 discloses a laser welding control device that takes an image of a machined portion irradiated with a laser beam and feedback-controls the output of the laser beam so as to achieve a target welding state.
Patent Literature 2 discloses a laser welding device that monitors the laser welding state in real time and corrects the laser irradiation position depending on whether there is a change in the welding state.

JP 2020-163413 A JP 2007-14974 A

The amount of heat input to the base material by the laser changes depending on the surface state of the base material or the stability of the output of the laser oscillator. When the amount of heat input is small, the wetting and penetration of the base metal are reduced, resulting in poor bead appearance and poor penetration. When the amount of heat input is large, poor burn-through occurs. In addition, when a large amount of heat is input when joining dissimilar materials, the formation of an intermetallic compound (IMC) is accelerated, resulting in poor joining.

However, the response time of feedback control in laser welding is not always sufficiently short, and there is a possibility that the amount of heat input to the base material cannot be made uniform only by adjusting the laser output.

SUMMARY OF THE INVENTION An object of the present invention is to provide a welding apparatus and a welding method that utilize a laser-arc hybrid welding method and are capable of more precisely controlling the amount of heat input to a base material.

A welding apparatus according to this aspect is a welding apparatus that welds a base material using both laser welding and arc welding, and includes an arc welding torch that generates an arc between a joint of the base material and the joint. A laser welding torch that irradiates a laser to a laser welding torch, a measurement unit that measures the state of laser welding using the laser welding torch, and based on the measurement results of the measurement unit, the arc welding using the arc welding torch is controlled. and a control unit.

In this aspect, the laser-arc hybrid welding method is used, and the amount of heat input to the base material can be precisely controlled. Welding defects due to excess or deficiency of heat input can be suppressed.

In the welding device according to this aspect, the control unit determines whether the heat input to the base material is excessive or insufficient based on the measurement result of the measuring unit, and when the heat input is insufficient, the output of the arc welding torch is increased and the output of the arc welding torch is reduced when the heat input is excessive.

In this aspect, when the heat input to the base material by laser welding is insufficient, the arc output is increased, and when the heat input is excessive, the arc output is decreased, so that feedback control of laser welding alone is sufficient. The amount of heat input to the base material can be controlled more precisely than in the case of controlling.

In the welding device according to this aspect, it is preferable that the measurement unit includes a photoelectric sensor and measures the emission intensity of plasma or the reflected light intensity of the laser due to laser welding using the laser welding torch.

In this aspect, it is possible to calculate the excess or deficiency of heat input to the base material with a simple configuration that measures the emission intensity of plasma by laser welding or the reflected light intensity of the laser. The amount of heat input can be precisely controlled.

The welding apparatus according to this aspect preferably has a configuration for measuring the emission intensity of plasma generated by laser welding when a short circuit or arc is extinguished in arc welding.

In this aspect, since the plasma emission intensity is measured at the time of arc welding short circuit or arc extinguishing, the plasma emission intensity due to laser welding is accurately measured, and the amount of excess or deficiency of heat input to the base material. can be calculated and controlled.

In the welding device according to this aspect, the control unit calculates the amount of excess or deficiency of heat input to the base material based on the emission intensity of plasma generated by laser welding, and the calculated excess or deficiency of heat input is used as an arc output. is converted into an excess/deficiency amount, and the output of the arc welding torch is increased or decreased based on the converted excess/deficiency amount.

In this aspect, it is possible to control the amount of heat input to the base material by converting the amount of heat input to the base material due to laser welding into the amount of arc output.

In the welding device according to this aspect, it is preferable that the measuring section has a field stop for transmitting plasma light from laser welding and blocking plasma light from arc welding.

In this aspect, the emission intensity of plasma generated by laser welding can be selectively measured among plasma generated by arc welding and laser welding, and the amount of heat input to the base material can be precisely controlled.

In the welding device according to this aspect, the control unit feedback-controls laser welding using the laser welding torch based on the measurement result of the measuring unit, and controls arc welding using the arc welding torch. configuration is preferred.

In this aspect, while feedback control of the laser output is performed, the arc output is adjusted when the adjustment of the heat input amount of the base material cannot catch up. That is, since the heat input amount of the base material is controlled in two stages, the heat input amount can be controlled more precisely.

The welding method according to this aspect is a welding method for welding the base material using both an arc welding torch that generates an arc between the joint of the base material and a laser welding torch that irradiates the joint with a laser. A state of laser welding using the laser welding torch is measured, and arc welding using the arc welding torch is controlled based on the measurement result.

In this aspect, the laser-arc hybrid welding method is used, and the amount of heat input to the base material can be precisely controlled. Welding defects due to excess or deficiency of heat input can be suppressed.

According to the above, it is possible to provide a welding apparatus and a welding method that can more precisely control the amount of heat input to a base material by using the laser-arc hybrid welding method.

1 is a schematic diagram illustrating a configuration example of a welding device according to Embodiment 1; FIG. 4 is a flowchart showing a welding processing procedure according to Embodiment 1; 4 is a graph showing the relationship between laser output and plasma emission intensity. It is an explanatory view showing composition of the 1st table and the 2nd table. FIG. 10 is a schematic diagram showing a configuration example of a measurement unit according to Embodiment 2;

A welding apparatus and a welding method according to embodiments of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. Moreover, at least part of the embodiments described below may be combined arbitrarily.

(Embodiment 1)
FIG. 1 is a schematic diagram illustrating a configuration example of a welding device 1 according to Embodiment 1. FIG. A welding apparatus 1 according to Embodiment 1 is a laser-arc hybrid welder that welds a base material 6 using both laser welding and arc welding. The welding device 1 includes a welding power source device 2 , a laser oscillation device 3 , a measurement section 4 and a control section 5 .

The welding power supply 2 is, for example, a consumable electrode gas shielded arc welder that uses a shielding gas. The welding power supply 2 includes an arc welding torch 21 that generates an arc between the base material 6 and the joint portion of the base material 6 to weld the base material 6, and a wire feeder 22 that feeds the welding wire 7 to the arc welding torch 21. and

Arc welding torch 21 has a contact tip that guides welding wire 7 to the joint of base material 6 . The arc welding torch 21 has a hollow cylindrical shape surrounding the contact tip, and has a nozzle for injecting a shielding gas such as argon gas or carbon dioxide gas to the joint portion of the base material 6 . The arc welding torch 21 receives a welding voltage and a welding current from the welding power supply 2, generates an arc between the tip of the welding wire 7 and the joint of the base material 6, and directs the shielding gas toward the weld. supply.

Welding power supply 2 generates a welding voltage and a welding current for performing arc welding, and outputs the generated welding voltage and welding current to arc welding torch 21 . The welding power supply 2 includes a voltage detector 23 that detects the welding voltage applied between the welding wire 7 and the base material 6, and a current detector 24 that detects the welding current supplied to the arc welding torch 21. Prepare. The output of the welding power supply 2 is feedback-controlled based on the detected welding voltage and welding current. The welding power supply 2 also controls feeding of the welding wire 7 .

The laser oscillation device 3 includes a laser welding torch 31 that irradiates a laser beam to the joint portion of the base material 6 . The laser welding torch 31 receives a laser beam supplied from the laser oscillation device 3 through an optical fiber, and irradiates the joint portion of the base material 6 with the laser beam. The laser welding torch 31 and the arc welding torch 21 are provided in a posture such that the laser irradiation portion and the joint to be arc-welded are close to each other. In the first embodiment, the laser irradiation position is forward and the arc generation part is backward with respect to the welding direction. That is, laser welding is performed first and then arc welding is performed on a certain joining portion. This welding order is an example, and the order of arc welding and laser welding performed on the joint is not particularly limited.

The measurement unit 4 is a device that measures the state of laser welding using the laser welding torch 31 in real time. The measurement unit 4 includes a spectroscope 41 and a photoelectric sensor 42 . Light emitted from the joint portion of the base material 6 being welded is incident on the measuring portion 4, the spectroscope 41 splits the incident light, and the photoelectric sensor 42 measures the intensity of the split light. In particular, the measurement unit 4 detects the emission intensity of plasma generated by laser welding, and outputs the detected emission intensity of the plasma to the control unit 5 .

The control unit 5 is a microcomputer that controls arc welding using the arc welding torch 21 and laser welding using the laser welding torch 31 . The control unit 5 has a timer. The control unit 5 feedback-controls the output of the welding power supply 2 based on the welding voltage and welding current detected by the voltage detector 23 and the current detector 24 . Further, the control unit 5 feedback-controls the laser output of the laser oscillation device 3 based on the measurement result of the measurement unit 4 .

The controller 5 adjusts the output of the welding voltage and the welding current based on the measurement result of the measuring unit 4, that is, the measured emission intensity of the plasma generated by laser welding. Hereinafter, the output of welding voltage and welding current will be referred to as arc output as appropriate. The control unit 5 stores a first table 51 storing constants for calculating the amount of excess or deficiency of heat input to the base material 6 by laser welding, and the excess or deficiency of the heat input related to laser welding according to the excess or deficiency of the arc output. and a second table 52 that stores coefficients for conversion to the shortage amount. Details of the first table 51 and the second table 52 will be described later.

FIG. 2 is a flow chart showing a welding processing procedure according to the first embodiment. During welding, the control unit 5 always repeatedly executes the following processing. The control unit 5 detects the welding voltage and the welding current with the voltage detector 23 and the current detector 24 (step S111), and determines whether or not a short circuit or arc extinguishing has occurred (step S112).

If it is determined that there is no short circuit or arc extinguishing (step S112: NO), the control unit 5 returns the process to step S111. If it is determined that the short circuit or the arc is extinguished (step S112: YES), the control unit 5 measures the emission intensity of the plasma generated by the laser welding in the measurement unit 4 (step S113). Then, the controller 5 feedback-controls the laser welding based on the measured emission intensity of the plasma (step S114). The emission intensity of the plasma has a correlation with the laser output or the heat input to the base material 6, as will be described later. The controller 5 increases the laser output when the plasma emission intensity is lower than the set output value, and reduces the laser output when the plasma emission intensity is higher than the set output value.

Next, the controller 5 calculates the excess or deficiency of heat input to the base material 6 by laser welding (step S115), and determines whether or not there is an excess or deficiency of heat input (step S116). When it is determined that there is no excess or deficiency of heat input (step S116: NO), the control unit 5 returns the process to step S111. If it is determined that there is an excess or deficiency of heat input, the controller 5 converts the calculated excess or deficiency into an excess or deficiency of arc output (step S117). Then, the controller 5 adjusts the output of the arc welding torch 21 based on the converted excess/deficiency (step S118). That is, the control unit 5 increases the output of the arc welding torch 21 when the heat input is insufficient, and decreases the output of the arc welding torch 21 when the heat input is excessive.

FIG. 3 is a graph showing the relationship between laser output and plasma emission intensity. The horizontal axis indicates the magnitude of the laser output or the amount of heat input to the base material 6, and the vertical axis indicates the emission intensity of the plasma generated by laser welding. As shown in FIG. 3, the emission intensity of the plasma and the amount of heat input to the base material 6 are in a proportional relationship within a predetermined range. The emission intensity is represented by the following formula.
I=0 (P≦x1)
α×P+β (x1≤P≤x2)
c (P≧x2)
however,
I: plasma emission intensity α, β by laser welding, c: constant P: laser output

The constants α, β and c are constants that depend at least on the material of the base material 6 . Further, in detail, the constants α, β, and c are constants that depend on the material of the base material 6, the type of laser, the welding position, etc. Therefore, by using the constants corresponding to these conditions, the laser output can be obtained more accurately. and the amount of heat input to the base material 6 can be calculated.

In FIG. 3, the region of c1≦I≦c2 is the laser output region where good bonding can be obtained. When the set output value for laser welding that provides a good joint is P0, the excess or deficiency W2 of the laser output per unit time is expressed as (I-β)/α-P0.

Also, the excess or deficiency of the laser output can be converted into the excess or deficiency of the arc output using the following formula.
W1=W2×d
however,
W1: excess or deficiency amount related to arc output W2: excess or deficiency amount related to laser output d: constant

The constant d is a value determined by experiments, and is a constant that depends on the material of the base material 6 .

FIG. 4 is an explanatory diagram showing the configurations of the first table 51 and the second table 52. As shown in FIG. FIG. 4A shows the contents of the first table 51. FIG. The first table 51 associates and stores the material of the base material 6, the type of laser, the welding posture, and the constants α, β, and c. The first table 51 may be configured to store information indicating the range in which good bonding can be obtained, such as the values of c1 and c2. Furthermore, the first table 51 may be configured to store information indicating a region in which the amount of heat input to the base material 6 by laser welding can be calculated, such as values of x1 and x2. FIG. 4B shows the contents of the second table 52. As shown in FIG. The second table 52 stores the type of material and the constant d in association with each other.

The welding apparatus 1 receives and stores information such as the type of the base material 6, the type of laser, and the welding posture when setting various welding conditions. The control unit 5 that executes step S115 reads the corresponding constants α, β, and c from the first table 51 using stored information such as the type of the base material 6, the type of laser, and the welding posture as keys, and reads the read constants and the measured emission intensity of the plasma, the laser output is calculated. Then, the control unit 5 calculates the difference between the calculated laser output and the set output value for laser welding as the amount of excess or deficiency of heat input to the base material 6 . The control unit 5 may compare the calculated laser output with the range in which good bonding can be obtained, and calculate the amount of excess or deficiency of heat input to the base material 6 .
In step S117, the controller 5 reads the constant d from the second table 52 using the type of the base material 6 to be stored as a key, and uses the read constant to calculate the excess or deficiency of the laser output. Convert to excess or deficiency of welding.

When an excess or deficiency of heat input occurs due to laser welding, the control unit 5 subtracts or adds the heat input deficiency W2 while the excess or deficiency of heat input occurs in arc welding subsequent to laser welding. , the heat input to the base material 6 can be controlled to be constant. In addition, when the excess or deficiency W2 of the heat input for laser welding occurs during the time T, the total excess or deficiency is increased by the amount W2 × (T / ΔT) of the heat input during the predetermined time ΔT seconds. It may be configured to compensate for the quantity W2*T. In other words, the period during which the arc output is increased or decreased in order to compensate for the excess or deficiency of heat input by laser welding is not particularly limited.

For example, the base material 6 is iron-aluminum dissimilar material joining (aluminum plate thickness 1.5 mm, galvanized steel plate 1.2 mm), various setting values are laser output of 300 to 1500 W, arc output of 1000 W, and welding speed of 50 cm/min. In this case, x1 is 0.6 [kW], x2 is 1 [kW], constant α is 10, constant β is −4, constant c is 8.0, and constant d is 0.8. It is assumed that good bonding can be obtained when the emission intensity I of the plasma generated by laser welding is 2 or more and 6 or less (2≤I≤6). When the emission intensity I of plasma generated by laser welding is 1, the laser output is 0.1 kW less than the set laser output for good welding conditions. In this case, the controller 5 can compensate for the heat input to the base material 6 by adjusting the arc output to 1080 W (1000 W+100 W×0.8) and control the amount of heat input to be constant.

(Example)
When the base material 6 is a lap fillet joint of a galvanized steel sheet having a plate thickness of 2.3 mm, welding was performed with an arc welding set output value of 200A-20V and a laser set output value of 4000W. In this welding, when the emission intensity of plasma generated by laser welding is lower than a set threshold value, the welding device 1 determines that the amount of heat input to the base material 6 is insufficient, and the arc output is determined according to the amount of insufficient heat input. As a result of adjusting, a good bead with no poor appearance was obtained.

According to the welding apparatus 1 and the welding method according to the first embodiment, the laser-arc hybrid welding method is used, the amount of heat input to the base material 6 can be precisely controlled, and welding defects due to excess or deficiency of heat input can be eliminated. can be suppressed.

Specifically, the welding device 1 can increase the arc output when the heat input to the base material 6 by laser welding is insufficient, and decrease the arc output when the heat input is excessive. The amount of heat input to the base material 6 can be controlled more precisely than when controlled only by feedback control of laser welding. Both insufficient heat input and excessive heat input can be dealt with.

In addition, the amount of heat input to the base material 6 can be calculated with a simple configuration for measuring the emission intensity of the plasma generated by laser welding, and the amount of heat input to the base material 6 can be precisely controlled. .

Furthermore, since the plasma emission intensity is measured at the time of arc welding short circuit or arc extinguishing, the plasma emission intensity due to laser welding is accurately measured, the excess or deficiency of heat input to the base material 6 is calculated, can be controlled.

Furthermore, the amount of heat input to the base material 6 by laser welding is calculated using constants according to the type of the base material 6, etc., and the constants corresponding to the type of the base material 6, etc. are used to calculate the amount of laser welding. Since the configuration converts the excess or deficiency of heat input into the excess or deficiency of arc output, the amount of heat input to the base material 6 can be controlled more precisely.

Furthermore, the welding apparatus 1 according to the first embodiment controls the arc output when the adjustment of the amount of heat input to the base material 6 cannot catch up while feedback-controlling the laser output. That is, since the heat input amount of the base material 6 is controlled in two stages, the heat input amount can be controlled more precisely.

In the first embodiment, an example in which the emission intensity of plasma generated by laser welding is measured and the amount of heat input to the base material 6 is calculated is explained. and the amount of excess or deficiency of heat input may be calculated. When the reflection intensity is low, the amount of heat input to the base material 6 tends to decrease, and the amount of heat input to the base material 6 can be calculated by measuring the reflection intensity. With a simple configuration for measuring the reflected light intensity of the laser, the excess or deficiency of the heat input to the base material 6 can be calculated, and the amount of heat input to the base material 6 can be controlled precisely.

(Embodiment 2)
A welding device 1 according to the second embodiment differs from that of the first embodiment in the configuration of a measurement unit 4 . Since other configurations are the same as those of the welding device 1 according to the first embodiment, similar portions are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 5 is a schematic diagram showing a configuration example of the measurement unit 4 according to the second embodiment. The measurement unit 4 according to the second embodiment has a field stop 43 that transmits plasma light from laser welding and blocks plasma light from arc welding. Since the measurement unit 4 can selectively measure the emission intensity of the plasma associated with laser welding, the control unit 5 can measure the emission intensity of the plasma due to laser welding without performing the process of step S112. .

REFERENCE SIGNS LIST 1 welding device 2 welding power supply device 3 laser oscillation device 4 measuring unit 5 control unit 6 base material 7 welding wire 21 arc welding torch 22 wire feeding device 23 voltage detector 24 current detector 31 laser welding torch 41 spectroscope 42 photoelectric sensor 51 first table 52 second table

Claims (6)

A welding device that welds a base material using both laser welding and arc welding,
an arc welding torch that generates an arc between the base metal joint;
a laser welding torch that irradiates the joint with a laser;
a measuring unit that measures the state of laser welding using the laser welding torch;
A welding device comprising: a control section that controls arc welding using the arc welding torch based on the measurement result of the measurement section. The control unit
Based on the measurement result of the measuring unit, the excess or deficiency of heat input to the base material is determined, and if the heat input is insufficient, the output of the arc welding torch is increased, and if the heat input is excessive, the 2. Welding equipment according to claim 1, wherein the power of the arc welding torch is reduced. 3. The welding device according to claim 1, wherein the measuring unit includes a photoelectric sensor and measures the intensity of emitted light of plasma or the intensity of reflected light of laser due to laser welding using the laser welding torch. The welding device according to claim 3, wherein the emission intensity of plasma generated by laser welding is measured during short circuiting or extinguishing of arc welding. The control unit
calculating the amount of excess or deficiency of heat input to the base material based on the emission intensity of the plasma generated by laser welding;
Convert the calculated excess or deficiency of heat input to the excess or deficiency of arc output,
The welding device according to any one of claims 2 to 4, wherein the output of the arc welding torch is increased or decreased based on the converted excess or deficiency. A welding method for welding the base material using both an arc welding torch that generates an arc between the joint of the base material and a laser welding torch that irradiates the joint with a laser,
Measuring the state of laser welding using the laser welding torch,
A welding method for controlling arc welding using the arc welding torch based on measurement results.

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