JP2023076109A - Welding device - Google Patents

Abstract

To achieve appropriate welding in shorter time than conventional welding.SOLUTION: A welding device includes: electrodes 80a and 80b which are opposite to each other so as to sandwich a joined product and pressurize the joined product; a welding power source 20; detection parts 10-14, 150 and 151 for detecting a physical amount relating to the joined product while welding; and a control part 15 for performing welding by first energization of supplying current to the electrodes 80a and 80b from the welding power source 20, stopping the first energization when the physical amount detected while welding satisfies a termination condition, and performing welding by second energization of supplying current to the electrodes 80a and 80b from the welding power source 20 again. The physical amount is a welding current flowing through the electrodes 80a and 80b, a welding voltage applied between the electrodes 80a and 80b, welding power supplied to the electrodes 80a and 80b, a current square time product that is a product of a square of welding current and lapsed time from start of the first energization, a temperature of the welded product, and a displacement magnitude in a thickness direction of the joined product.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a welding device, and more particularly to a welding device suitable for joining a plurality of laminates of ferrous metal foils.

In recent years, a laminated lithium ion battery in which a plurality of flat plate-shaped positive electrodes and negative electrodes are laminated with separators interposed therebetween has been used. FIG. 11(A) is a perspective view showing a state after lamination of the laminated lithium ion battery, and FIG. 11(B) is a perspective view showing a state where the electrode tabs and lead terminals are connected.

In a laminated lithium ion battery, as shown in FIG. 11A, a positive electrode 100 made of metal foil and a negative electrode 101 made of metal foil are alternately stacked with a separator (not shown) interposed therebetween. Each positive electrode 100 is provided with a tab 102 for lead connection. These tabs 102 are stacked as shown in FIG. be done. Similarly, each negative electrode 101 is provided with a tab 103 for lead connection, and these tabs 103 are laminated and joined to a lead terminal 105 for external connection at a joint portion 107 .

In conventional lithium-ion batteries, ultrasonic bonding has often been used to bond aluminum foils and copper foils that are generally used as current collectors (positive electrode 100 and negative electrode 101).
On the other hand, in the development of next-generation batteries, there is a movement to apply stainless steel as a current collector because of its excellent corrosion resistance and mechanical properties. Stainless steel and other iron-based metals are not suitable for ultrasonic welding from the viewpoint of abrasion of the ultrasonic horn and anvil (receiving jig) and adhesion of the workpiece, and are suitable for joining by resistance welding.

As shown in FIG. 12, resistance welding is performed by sandwiching and pressing a plurality of tabs 102 (or tabs 103) and lead terminals 104 (or lead terminals 105) between a pair of electrodes 108a and 108b from above and below. In this method, an electric current is applied between 108b to raise the temperature of the tab 102 (or the tab 103) and the lead terminal 104 (or the lead terminal 105) by the generated Joule heat, thereby joining them.

Resistance welding of iron-based metals is easy, but the resistance value increases when a large number of iron-based metal foils are laminated. Stable bonding could not be obtained due to the generation of spatter and dust, and the adherence of metal foil to the electrodes.

Therefore, in the technique disclosed in Patent Document 1, at least a portion of the overlapped portion of the metal foil is brought into close contact while applying a pressing force to at least a portion of the overlapped portion, thereby leveling at least a portion of the overlapped portion and increasing the electrical resistance value. After performing the preliminary process of forming the leveled portion, the resistance welding of the main process is performed. However, the technique disclosed in Patent Literature 1 has a problem that welding takes a long time because a preliminary process is required.

JP 2020-66017 A

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a welding apparatus capable of realizing appropriate welding in a shorter time than conventional ones, even when welding a plurality of laminates of iron-based metal foils. intended to provide

The welding apparatus of the present invention comprises first and second electrodes facing each other with an object to be welded therebetween and configured to pressurize the object to be welded, and a current flowing between the first and second electrodes. a detection unit configured to detect one or more physical quantities relating to the object to be welded during welding; and the first and second Welding is performed by a first energization that supplies a current between the electrodes, and the first energization is stopped at the time when the one or more physical quantities detected during the welding satisfy a predetermined termination condition, and the welding a controller configured to perform welding by a second energization that re-supplies current from a power supply to between the first and second electrodes, wherein the physical quantity flows between the first and second electrodes. Welding current, welding voltage applied between the first and second electrodes, welding power supplied between the first and second electrodes, the square of the welding current and the time from the start of the first energization It is characterized by the current squared time product which is the product with the elapsed time, the temperature of the object to be welded, and the amount of displacement in the thickness direction of the object to be welded.

In one configuration example of the welding apparatus of the present invention, the control unit performs constant voltage control type welding that supplies a predetermined welding voltage between the first and second electrodes as the welding by the first energization; Alternatively, constant power control type welding that supplies a predetermined welding power between the first and second electrodes, or intermittent constant voltage that intermittently supplies a predetermined welding voltage between the first and second electrodes. It is characterized by performing controlled welding or intermittent constant power control welding in which a predetermined welding power is intermittently supplied between the first and second electrodes.
In one configuration example of the welding apparatus of the present invention, the control unit performs constant current control type welding that supplies a predetermined welding current between the first and second electrodes as the welding by the second energization; Alternatively, welding is performed by an intermittent constant current control system in which a predetermined welding current is intermittently supplied between the first and second electrodes.
In one configuration example of the welding apparatus of the present invention, the control unit performs welding by a constant current control system that supplies a predetermined welding current between the first and second electrodes as the welding by the second energization. When the one or more physical quantities detected during welding meet a predetermined cooling start condition, the welding current is lowered at a predetermined slope.
In one configuration example of the welding apparatus of the present invention, the control unit performs welding by a constant current control system that supplies a predetermined welding current between the first and second electrodes as the welding by the second energization. The time from the start of the first energization to the predicted end of the second energization when one or more of the physical quantities detected during the welding satisfies a predetermined cooling start condition is predetermined. The method is characterized by calculating the slope when the welding current is decreased so as to approach the target time, and decreasing the welding current at the calculated slope.
Further, in one structural example of the welding apparatus of the present invention, the object to be welded comprises a laminate in which a plurality of metal foils are laminated.

According to the present invention, it is possible to prevent the generation of spatter and dust, and to prevent the adherence of the object to be welded to the electrode, so that even when welding a laminate of a plurality of iron-based metal foils, stable welding can be achieved. can be realized. Moreover, since the present invention does not require a conventional preliminary process, it is possible to shorten the time required for welding.

FIG. 1 is a block diagram showing the construction of a welding apparatus according to a first embodiment of the invention. FIG. 2 is an enlarged sectional view of the welding head according to the first embodiment of the invention. FIG. 3 is a diagram showing an example of changes in welding current, welding voltage, welding power, and inter-electrode resistance during welding. FIG. 4 is a flow chart showing the operation of the welding device according to the first embodiment of the present invention. FIG. 5 is a diagram showing an example of the reference waveform of the welding voltage during the first energization in the first embodiment of the present invention. FIG. 6 is a diagram showing an example of the reference waveform of the welding current during the second energization in the first embodiment of the present invention. FIG. 7 is a diagram showing an example of a reference waveform of welding power during the first energization in the first embodiment of the present invention. FIG. 8 is a diagram showing an example of the reference waveform of the welding current during the second energization in the second embodiment of the present invention. FIG. 9 is a flow chart showing the operation of the welding device according to the second embodiment of the invention. FIG. 10 is a block diagram showing an example configuration of a computer that implements the welding apparatus according to the first and second embodiments of the present invention. FIG. 11 is a perspective view showing a state after lamination of the laminated lithium ion battery and a state in which the tabs of the electrodes and the lead terminals are connected. FIG. 12 is an enlarged cross-sectional view of a joint in resistance welding.

[First embodiment]
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the construction of a welding apparatus according to a first embodiment of the invention. The welding apparatus of this embodiment includes a start switch 2, a rectifier circuit 3, a capacitor 4, an inverter 5, a welding transformer 6, a diode 7, a welding head 8, a hall element 9, and a current detector 10. , a voltage detection unit 11, a temperature detection unit 12, a load detection unit 13, a displacement detection unit 14, a control unit 15, an operation unit 16, a storage unit 17, and waveforms of physical quantities detected during welding, for example and a display unit 18 for displaying.

Start switch 2 , rectifier circuit 3 , capacitor 4 , inverter 5 , welding transformer 6 and diode 7 constitute welding power source 20 that supplies current to welding head 8 . Further, the Hall element 9, the current detection unit 10, the voltage detection unit 11, the temperature detection unit 12, the load detection unit 13, the displacement detection unit 14, the power detection unit 150 and the current squared time product detection unit 151, which will be described later, are connected during welding. constitutes a detection unit for detecting a physical quantity related to the object to be welded.

FIG. 2 is an enlarged sectional view of the welding head 8. FIG. The welding head 8 is provided with electrodes 80a and 80b facing each other with an object 85 to be welded therebetween and configured to apply pressure to the object 85 to be welded. The electrodes 80a and 80b are composed of electrode bodies 81a and 81b made of a copper alloy such as chromium copper (Cu--Cr) or alumina-dispersed copper (Cu-- _{Al.sub.2 O.sub.3} ), the above copper alloy, or molybdenum (Mo), Tip portions 82a and 82b made of an alloy containing at least one of tungsten (W), iron (Fe), nickel (Ni), and titanium (Ti). Furthermore, the welding head 8 includes thermocouples 83a and 83b attached to the tip portions 82a and 82b, and pressure mechanisms 84a and 84b that move the electrodes 80a and 80b up and down to pinch and press the object 85 to be welded. .

The pressure mechanisms 84a and 84b are provided with load cells (not shown) so that the magnitude of the load applied to the article 85 to be welded can be converted into an electric signal. Further, the pressing mechanisms 84a and 84b are provided with a displacement sensor (not shown) so that the amount of displacement of the object 85 in the thickness direction can be converted into an electric signal. Although the temperature of the tip portions 82a and 82b can be detected based on the voltage from the thermocouples 83a and 83b, radiation thermometers may be provided instead of the thermocouples 83a and 83b.

The operation of the welding device will be described below. In this embodiment, a laminated body in which a plurality of tabs 102 and lead terminals 104 are laminated will be described as an object 85 to be bonded. The tab 102 is made of, for example, iron-based metal foil.
First, the pressure mechanisms 84a and 84b of the welding head 8 sandwich and press the article 85 to be welded from above and below (in the direction along the stacking direction of the laminate) with the electrodes 80a and 80b as shown in FIG. In the example of FIG. 2, the pressurizing mechanisms 84a and 84b apply pressure to the electrodes 80a and 80b, respectively. Needless to say.

For example, when the user operates the operation unit 16 to instruct welding start, a start signal is output from the operation unit 16 and the start switch 2 is turned on. When the start switch 2 is turned on, the rectifier circuit 3 full-wave rectifies the AC output of the 200 V AC commercial three-phase AC power supply 1 and charges the capacitor 4 connected in parallel between the output terminals of the rectifier circuit 3 . This rectifier circuit 3 is composed of a three-phase full-wave mixing bridge using six diodes 30 .

The inverter 5 converts the charging voltage of the capacitor 4 into an AC voltage and supplies it to the primary side of the welding transformer 6 . The inverter 5 is composed of a bridge consisting of four NPN transistors 50 . A secondary side output of the welding transformer 6 is full-wave rectified by a rectifier (diode) 7 and guided to electrodes 80a and 80b. As a result, a large current is passed between the electrodes 80a and 80b, and the temperature of the joint surface (the joint surface between the metal foils) of the object 85 to be joined is increased by the generated Joule heat to join them.

The current detection unit 10 detects the current I flowing through the secondary side of the welding transformer 6 (that is, the welding current flowing through the electrodes 80a and 80b) from the output of the Hall element 9 provided on the secondary side of the welding transformer 6. . Voltage detector 11 detects welding voltage V applied between electrodes 80a and 80b.

The temperature detection unit 12 detects the temperature T of the article 85 (the temperature of the tip portions 82a and 82b) based on the voltages from the thermocouples 83a and 83b. As described above, instead of the thermocouples 83a and 83b, a radiation thermometer may be used to detect the temperature T of the object 85 to be welded. The load detection unit 13 detects the load G applied to the workpiece 85 based on the output of the load cells provided in the pressure mechanisms 84a and 84b. The displacement detector 14 detects the displacement amount D of the object 85 in the thickness direction based on the output of the displacement sensors provided in the pressure mechanisms 84a and 84b.

A power detection unit 150 provided in the control unit 15 multiplies the value of the welding current I detected by the current detection unit 10 and the value of the welding voltage V detected by the voltage detection unit 11, thereby providing power to the electrodes 80a and 80b. The supplied welding power W is detected. A current squared time product detection unit 151 provided in the control unit 15 calculates a current squared time product I ² t, which is the product of the square of the welding current I and the elapsed time t from the start of energization.

FIG. 3 is a diagram showing an example of changes in welding current I, welding voltage V, welding power W, and inter-electrode resistance R during welding, and FIG. 4 is a flow chart showing the operation of the welding apparatus of this embodiment.
In this embodiment, the electrodes 80a and 80b are energized twice, ie, the first energization and the second energization. I do.

The storage unit 17 stores, as desirable welding conditions, reference waveforms of desirable energizations to the electrodes 80a and 80b for each of the first and second energizations. In this embodiment, the reference waveform of the welding voltage V is set as the welding condition for the first energization, and the reference waveform of the welding current I is set as the welding condition for the second energization. The storage unit 17 also stores a condition for ending the first energization and a condition for starting cooling for the second energization.

First, the control unit 15 applies current to the electrodes 80a and 80b by operating the inverter 5 to generate an AC voltage. Then, the control unit 15 monitors the welding voltage V detected by the voltage detection unit 11 in real time, and the welding voltage V at the present time when the elapsed time from the start of the first energization is t is stored in the storage unit 17. The on/off of the transistor 50 of the inverter 5 is controlled to control the amount of energization to the electrodes 80a and 80b so as to match the value at the elapsed time t on the reference waveform of the welding voltage V obtained.

FIG. 5 is a diagram showing an example of the reference waveform of the welding voltage V during the first energization. In the reference waveform of the welding voltage V of this embodiment, for example, the set voltage Vsp, the rise time t1 up to the set voltage Vsp, and the waveform up to the set voltage Vsp are defined. Thus, by controlling the amount of energization to the electrodes 80a and 80b so that the waveform of the welding voltage V matches the reference waveform, a constant welding voltage V is applied between the electrodes 80a and 80b by the first energization as shown in FIG. is supplied to perform constant voltage control welding (step S1 in FIG. 4).

Next, the control unit 15 determines whether or not the condition for ending the first energization is satisfied (step S2 in FIG. 4). The termination conditions for the first energization include the termination condition value of the welding current I, the termination condition value of the welding power W, the termination condition value of the current squared time product I ² t, and the termination condition value of the temperature T of the object 85 to be welded (temperature range), duration, end condition value of the displacement amount D of the object 85 to be welded in the thickness direction, and the like.

When the welding current I detected by the current detection unit 10 reaches or exceeds the first energization termination condition value (current) stored in the storage unit 17, the control unit 15 satisfies the first energization termination condition. It is determined that When the welding power W calculated by the power detection unit 150 reaches or exceeds the first energization termination condition value (power) stored in the storage unit 17, the control unit 15 determines that the first energization termination condition is established. It may be determined that

In addition, the control unit 15 determines that the current squared time product I ² t calculated by the current squared time product detection unit 151 reaches or exceeds the end condition value (current squared time product) of the first energization stored in the storage unit 17. It may be determined that the termination condition of the first energization is satisfied when the first energization is performed. Further, when the temperature T of the object to be welded 85 detected by the temperature detection unit 12 reaches or exceeds the first energization termination condition value (temperature) stored in the storage unit 17, the control unit 15 controls the first It may be determined that the energization end condition is satisfied. Further, the control unit 15 controls that the amount of displacement D in the thickness direction of the workpiece 85 detected by the displacement detection unit 14 reaches or exceeds the first energization end condition value (displacement amount) stored in the storage unit 17. It may be determined that the termination condition of the first energization is satisfied when the first energization is performed.

The control unit 15 stops the operation of the inverter 5 when it is determined that the condition for ending the first energization is satisfied, thereby terminating the first energization to the electrodes 80a and 80b (step S3 in FIG. 4). In the example of FIG. 3, when the welding current I rises to the termination condition value (current) for the first energization, it is determined that the termination condition for the first energization is met, and the first energization is terminated.

In the above example, the first energization is terminated when one termination condition is satisfied. good.

Next, the control unit 15 applies current to the electrodes 80a and 80b by operating the inverter 5 again to generate an AC voltage. Then, the control unit 15 monitors the welding current I detected by the current detection unit 10 in real time, and the welding current I at the present time when the elapsed time from the start of the second energization is t is stored in the storage unit 17. The on/off of the transistor 50 of the inverter 5 is controlled to control the amount of electricity supplied to the electrodes 80a and 80b so as to match the value at the elapsed time t on the reference waveform of the welding current I.

FIG. 6 is a diagram showing an example of the reference waveform of the welding current I during the second energization. In the reference waveform of the welding current I of this embodiment, for example, the set current Isp, the rise time t2 up to the set current Isp, the waveform up to the set current Isp, the time t3 from the start of cooling to the end of energization, and the start of cooling A waveform from the point in time to the end of energization is defined. Thus, by controlling the amount of energization to the electrodes 80a and 80b so that the waveform of the welding current I matches the reference waveform, a constant welding current I is applied to the electrodes 80a and 80b by the second energization as shown in FIG. Welding is performed by controlling the supplied constant current (step S4 in FIG. 4).

Next, the control unit 15 determines whether or not the cooling start condition is satisfied (step S5 in FIG. 4). The value of the welding voltage V is one of the cooling start conditions. The control unit 15 determines that the cooling start condition is met when the welding voltage V detected by the voltage detection unit 11 becomes equal to or lower than the cooling start condition value (voltage) stored in the storage unit 17 .

Control unit 15 adjusts electrodes 80a and 80b so that welding current I detected by current detection unit 10 coincides with the reference waveform from the cooling start time shown in FIG. The welding current I is lowered by controlling the amount of electricity supplied to (step S6 in FIG. 4). In this embodiment, by gradually decreasing the welding current I to gradually cool the object 85 to be welded, good welding quality can be achieved. The second energization ends when the amount of energization to the electrodes 80a and 80b becomes 0 (step S7 in FIG. 4).

As described above, in this embodiment, the physical quantity detected during welding is monitored in real time when performing resistance welding of the object 85 to be welded, and when the physical quantity reaches a predetermined end condition value, the electrode 80a is turned off. , 80b is terminated and the second energization is started, and the bonding of the object 85 to be bonded is completed by supplying the current required for bonding.

In this embodiment, the constant voltage control type welding by the first energization breaks the oxide film present on the surface of the metal foil to secure the energization path. If the second energization is performed without securing the energization path by the first energization, a high voltage is instantaneously applied to flow the set current value, causing sputtering, adhesion of metal foil to the electrodes 80a and 80b, and adhesion of the metal foil to the electrodes 80a and 80b. Abrasion or the like occurs at the tip of the joint, making it difficult to achieve stable joining.

Also, in order to break the surface oxide film of the object to be bonded 85 in the first energization, it is necessary to make the set voltage Vsp relatively high. At this time, if the reaction speed in switching the control is slow, a large current may flow instantaneously. Therefore, by measuring and controlling the physical quantity during the first energization, quick control switching to the second energization is realized. Even if the number of laminated metal foils and the welding conditions are the same, the time from the start of the first energization to the satisfaction of the termination conditions is not always the same depending on the surface condition and strain condition of the metal foil. Therefore, if control switching is performed at a predetermined time without measuring the physical quantity at the time of the first energization, the energization path cannot be secured in the first energization at some times, and the required value is exceeded at other times. It happens that a large current flows.

According to this embodiment, it is possible to prevent the generation of spatter and dust, prevent the metal foil from adhering to the electrodes 80a and 80b, and realize stable bonding of the iron-based metal foil laminate. .

In this example, the preliminary process disclosed in Patent Document 1 is not required. Although the preliminary process takes time, the total time of the first energization and the second energization in this embodiment is, for example, about 100 ms. Therefore, according to this embodiment, the time required for welding can be shortened.

In this embodiment, the constant voltage control type welding is performed as the welding at the time of the first energization, but the constant power control type welding may be performed. In this case, the reference waveform of the welding power W of the first energization is stored in advance in the storage unit 17 . FIG. 7 is a diagram showing an example of the reference waveform of the welding power W during the first energization. In the reference waveform of the welding power W of this embodiment, for example, the set power Wsp, the rise time t1 up to the set power Wsp, and the waveform up to the set power Wsp are defined.

The control unit 15 controls the welding power W at the present time when the elapsed time t from the start of the first energization matches the value at the elapsed time t on the reference waveform of the welding power W stored in the storage unit 17. What is necessary is just to control the amount of electricity to the electrodes 80a and 80b. Needless to say, when welding is performed using the constant power control method, the termination condition value of the welding power W is not used as the termination condition value for the first energization.

Note that the control unit 15 determines that the cooling start condition is satisfied when the welding power W calculated by the power detection unit 150 becomes equal to or less than the cooling start condition value (power) stored in the storage unit 17. You may do so. Further, the control unit 15 controls when the temperature T of the workpiece 85 detected by the temperature detection unit 12 reaches a cooling start condition value (temperature) stored in the storage unit 17 or more, or when the temperature T reaches the storage unit It may be determined that the cooling start condition is satisfied when the state of being within the range of the cooling start condition value (temperature) stored in the storage unit 17 continues for the duration time stored in the storage unit 17 or longer. . Further, the control unit 15 detects when the amount of displacement D in the thickness direction of the workpiece 85 detected by the displacement detection unit 14 reaches the cooling start condition value (displacement amount) stored in the storage unit 17 or more. , it may be determined that the cooling start condition is satisfied.
In the above example, cooling is started when one cooling start condition is satisfied, but cooling may be started when a plurality of cooling start conditions are satisfied instead of one cooling start condition.

[Second embodiment]
In the first embodiment, the welding current I is gradually decreased when the cooling start condition is satisfied during the second energization. There is a possibility that the time required for welding (the time from the start of the first energization to the end of the second energization) will vary greatly due to the variation in the timing of welding. Therefore, instead of decreasing the welding current I at a predetermined slope as shown in FIG. You can adjust the tilt.

Also in the present embodiment, the configurations of the welding apparatus and the objects to be welded are the same as those of the first embodiment, so the reference numerals in FIGS. 1 and 2 will be used for description.
FIG. 8 is a diagram showing an example of the reference waveform of the welding current I during the second energization in this embodiment. The difference from FIG. 6 is that the waveform from the start of cooling to the end of energization is not defined.

FIG. 9 is a flow chart showing the operation of the welding device of this embodiment. The processing of steps S1 to S5 is the same as in the first embodiment.

When the control unit 15 determines that the cooling start condition is satisfied (YES in step S5 in FIG. 9), the set current Isp, the time required from the start of the first energization to the start of cooling by the second energization, and , and a predetermined target time, the welding current I is decreased from the set current Isp to 0 so that the time from the start of the first energization to the expected end of the second energization approaches the target time. is calculated (step S8 in FIG. 9).

Then, the control section 15 controls the amount of energization to the electrodes 80a and 80b so that the welding current I detected by the current detection section 10 decreases with the slope calculated in step S8 (step S9 in FIG. 9). The second energization ends when the amount of energization to the electrodes 80a and 80b becomes 0 (step S10 in FIG. 9).
Thus, in this embodiment, the time from the start of the first energization to the end of the second energization can be brought closer to the target time.

The time required from the start of the first energization to the start of cooling in the second energization has already exceeded the target time. is longer than the target time, a predetermined slope (for example, a slope close to vertical descent) may be set.

In the first and second embodiments, the object to be bonded 85 is a laminate of a plurality of iron-based metal foils, but the object to be bonded 85 is not limited to this. 85, a laminate of a plurality of nickel alloy plates may be used as the object to be bonded 85, a laminate of a plurality of aluminum plates may be used as the object to be bonded 85, or an aluminum alloy may be used. A laminate of a plurality of plates made of copper or a copper alloy may be used as the object 85 to be joined. Alternatively, the object to be bonded 85 may be a laminate obtained by laminating a plurality of plates made of aluminum alloy or plates made of copper or copper alloy.

In addition, in the first and second embodiments, examples of performing constant voltage control type welding or constant power control type welding as welding at the time of the first energization have been described, but pulse control type welding is performed. may That is, welding may be performed by an intermittent constant voltage control system in which a predetermined welding voltage is intermittently supplied between the electrodes 80a and 80b, or a predetermined welding power may be intermittently supplied between the electrodes 80a and 80b. You may make it weld by the intermittent constant power control system which carries out. Similarly, in the first and second embodiments, an example in which constant current control type welding is performed as welding during the second energization has been described, but intermittent constant current control type welding may also be performed. .

The functions of the control unit 15, the operation unit 16, the storage unit 17, and the display unit 18 of the first and second embodiments are a computer having a CPU (Central Processing Unit), a storage device, and an interface with the outside, and It can be implemented by a program that controls hardware resources. FIG. 10 shows a configuration example of this computer.

The computer includes a CPU 200 , a storage device 201 and an interface device (hereinafter abbreviated as I/F) 202 . The I/F 202 is connected with the welding power source, the current detection unit 10, the voltage detection unit 11, the temperature detection unit 12, the load detection unit 13, the displacement detection unit 14, and the like. In such a computer, a program for implementing the method of the present invention is stored in storage device 201 . The CPU 200 executes the processes described in the first and second embodiments according to programs stored in the storage device 201 .

INDUSTRIAL APPLICABILITY The present invention can be applied to resistance welding equipment.

DESCRIPTION OF SYMBOLS 1... 3-phase AC power supply, 2... Start switch, 3... Rectifier circuit, 4... Capacitor, 5... Inverter, 6... Welding transformer, 7... Diode, 8... Welding head, 9... Hall element, 10... Current detector, DESCRIPTION OF SYMBOLS 11... Voltage detection part 12... Temperature detection part 13... Load detection part 14... Displacement detection part 15... Control part 16... Operation part 17... Storage part 18... Display part 20... Welding power supply 80a , 80b... Electrode 81a, 81b... Electrode main body 82a, 82b... Tip part 83a, 83b... Thermocouple 84a, 84b... Pressurizing mechanism 85... Object to be welded 150... Power detector 151... Current squared Time product detector.

Claims (6)

first and second electrodes facing each other with an object to be bonded interposed therebetween and configured to pressurize the object to be bonded;
a welding power source that supplies current between the first and second electrodes;
a detection unit configured to detect one or more physical quantities related to the object to be welded during welding;
Welding is performed by first energization in which current is supplied from the welding power source to between the first and second electrodes in response to an instruction from the outside, and one or more of the physical quantities detected during this welding reaches a predetermined end. a control unit configured to perform welding by a second energization that stops the first energization when a condition is satisfied and re-supplies current from the welding power source to between the first and second electrodes; prepared,
The physical quantities include welding current flowing between the first and second electrodes, welding voltage applied between the first and second electrodes, welding power supplied between the first and second electrodes, The current squared time product, which is the product of the square of the welding current and the elapsed time from the start of the first energization, the temperature of the object to be welded, and the amount of displacement in the thickness direction of the object to be welded. and welding equipment. The welding device according to claim 1,
The controller controls, as the welding by the first energization, welding of a constant voltage control system that supplies a predetermined welding voltage between the first and second electrodes, or welding of a predetermined welding voltage between the first and second electrodes. Welding of a constant power control system that supplies welding power, or welding of an intermittent constant voltage control system that intermittently supplies a predetermined welding voltage between the first and second electrodes, or welding of the first and second electrodes. A welding apparatus for performing intermittent constant power control welding in which a predetermined welding power is intermittently supplied between electrodes. The welding device according to claim 1 or 2,
The control unit controls, as the welding by the second energization, welding of a constant current control system that supplies a predetermined welding current between the first and second electrodes, or intermittent welding between the first and second electrodes. Welding equipment characterized by performing intermittent constant current control type welding in which a predetermined welding current is supplied to. The welding device according to any one of claims 1 to 3,
The control unit performs welding by a constant current control system that supplies a predetermined welding current between the first and second electrodes as the welding by the second energization, and one or more detected during this welding A welding apparatus, wherein a welding current is lowered at a predetermined slope when said physical quantity satisfies a predetermined cooling start condition. The welding device according to any one of claims 1 to 3,
The control unit performs welding by a constant current control system that supplies a predetermined welding current between the first and second electrodes as the welding by the second energization, and one or more detected during this welding When the welding current is lowered so that the time from the start of the first energization to the expected end of the second energization approaches a predetermined target time when the physical quantity satisfies a predetermined cooling start condition. A welding device that calculates an inclination and lowers a welding current according to the calculated inclination. The welding device according to any one of claims 1 to 5,
A welding device, wherein the object to be welded is a laminate in which a plurality of metal foils are laminated.

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