WO2013031717A1 - Capacitor type welding method and welding device - Google Patents
Capacitor type welding method and welding device Download PDFInfo
- Publication number
- WO2013031717A1 WO2013031717A1 PCT/JP2012/071556 JP2012071556W WO2013031717A1 WO 2013031717 A1 WO2013031717 A1 WO 2013031717A1 JP 2012071556 W JP2012071556 W JP 2012071556W WO 2013031717 A1 WO2013031717 A1 WO 2013031717A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- welding
- capacitor
- current
- electrode
- discharge
- Prior art date
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K11/00—Resistance welding; Severing by resistance heating
- B23K11/24—Electric supply or control circuits therefor
- B23K11/26—Storage discharge welding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K11/00—Resistance welding; Severing by resistance heating
- B23K11/24—Electric supply or control circuits therefor
Definitions
- the present invention relates to a capacitor type welding method and a welding apparatus for welding an object to be welded by discharging energy stored in a welding capacitor by a charging circuit between welding electrodes in a short time via a welding transformer.
- the capacitor-type welding device stores welding power in the welding capacitor over a long time compared to the discharge time, and discharges it at once in a short time. For this reason, compared with a general alternating current welding apparatus, there is an advantage in terms of equipment that the power receiving equipment does not increase in capacity. In addition, since the degree to which the workpiece is heated is small, there are almost no weld marks (burns) at the welding location, and there is an advantage that distortion and the like are small. Capacitor-type welding equipment is widely used in small to large industrial equipment.
- the capacitor type welding apparatus generally uses a capacitor bank in which a large number of electrolytic capacitors are connected in parallel as a welding capacitor (for example, see Patent Document 1).
- a predetermined pressure forging pressure
- the welding capacitor is charged in parallel.
- the charging circuit is turned off, and the discharging switch is turned on while the welding electrode applies pressure to the workpiece.
- the discharge switch is turned on, a steeply increasing pulsed current flows through the primary winding of the welding transformer.
- the secondary winding of the welding transformer is about one turn and is significantly less than the number of turns of the primary winding, a pulsed welding current that is significantly larger than the primary current flows in the secondary winding.
- the welding object can be welded by this welding current, and a welded article can be obtained in a short time.
- Some conventional capacitor-type welding apparatuses have a longer discharge current, that is, a wave tail of the welding current, depending on the circuit constant of the discharge circuit of the welding capacitor.
- Capacitor-type welding equipment that has a long wave tail welding current cuts the wave tail of the welding current that does not affect the welding result in consideration of the mechanical operation time of the welding electrode when welding is performed in a short cycle. . That is, when a small welding current is still flowing between the welding electrodes, the welding cycle is shortened by moving the welding electrodes in a direction in which the welding electrodes are opened.
- Patent Document 2 a one-way impedance circuit in which a diode and an impedance are connected in series is used between primary windings of a welding transformer in order to prevent afterflash.
- This one-way impedance circuit is an effective means for preventing afterflash that occurs when the welding electrodes are opened between the welding electrodes in a state in which the wave tail portion of the welding current flows between the welding electrodes.
- the capacitor welding method and welding apparatus of the present invention utilize vibration (resonance) between an inductance component in a circuit and a capacitor component such as a welding capacitor. Due to the vibration operation of the inductance component and the capacitor component, the discharge current waveform of the welding capacitor becomes a waveform close to a sine wave, so that a long wave tail that affects the welding cycle does not occur. Therefore, in the present invention, when shortening the welding cycle, it is not necessary to consider the wave tail of the welding current. However, since it has been found that the exciting current of the welding transformer becomes a problem, the problem caused by this exciting current is solved.
- the excitation current of the welding transformer when the welding capacitor is discharged will be described in detail later and will be briefly described here.
- the discharge switch When the discharge switch is turned on and the charging voltage of the welding capacitor is applied to the primary winding of the welding transformer, an exciting current flows through the primary winding. If the discharge switch is turned off while the exciting current is flowing in the primary winding, the exciting current flowing in the primary winding is commutated to the secondary winding of the welding transformer, and the secondary winding and the welding Reflux through electrode.
- the excitation current is commutated in the secondary winding, the welding current accompanying the discharge of the charging charge of the welding capacitor has already disappeared and does not flow through the secondary winding.
- the impedance between the welding electrodes after the welding is finished is very small, and the resistance component of the circuit on the secondary side of the welding transformer is made small. For this reason, the exciting current hardly disappears by being consumed in the secondary circuit of the welding transformer within a few seconds after the welding current disappears.
- Patent Document 1 describes a capacitor-type welder, but when a current is flowing between the welding winding and the secondary winding of the welding transformer, the welding electrodes are opened, of course, There is no description about the problems.
- Patent Document 1 after current is released between the secondary windings of the welding transformer and the welding electrodes are opened, afterflash occurs, and a large surge voltage is generated in the primary winding. appear. For this reason, it is necessary to use a discharge switch or a charging circuit having a high withstand voltage.
- Patent Document 2 discloses an operation in which the excitation current flowing in the primary winding of the welding transformer commutates to the secondary winding, or between the welding electrodes when the excitation current flows in the secondary winding. There is no description of the problem of opening and the method and means for solving the problem.
- the discharging switch for discharging the charging charge of the welding capacitor is set to be on. It is possible to prevent an after flash from occurring when opening the welding electrodes through which an exciting current flows, or a surge voltage from being generated in the primary winding.
- the first invention charges the welding capacitor with the electric power fed from the charging circuit, turns on the discharge switch, and discharges the charging charge charged in the welding capacitor to the primary winding of the welding transformer, Capacitor type in which a welding current is passed through a workpiece through a secondary winding of the welding transformer and a first welding electrode and a second welding electrode connected to the secondary winding to weld the workpiece.
- Capacitor type in which a welding current is passed through a workpiece through a secondary winding of the welding transformer and a first welding electrode and a second welding electrode connected to the secondary winding to weld the workpiece.
- the drive signal is a continuous signal or a signal that is intermittent at a high frequency, and the drive signal discharges the charge charged in the welding capacitor.
- Proposed is a capacitor-type welding method which is applied to a semiconductor switch and then applied to at least the semiconductor switch until the gap between the first welding electrode and the second welding electrode is opened. .
- the drive signal is a continuous signal or a signal that is intermittent at a high frequency, and the drive signal discharges the charge charged in the welding capacitor.
- the drive signal After being applied to the semiconductor switch, the drive signal is removed from the semiconductor switch and applied again to at least the semiconductor switch immediately before opening the gap between the first welding electrode and the second welding electrode.
- the charge due to the surge current charged in the welding capacitor when the discharge switch is turned on again is the polarity of the charge charge.
- the reverse polarity charge is opposite to the charge charge, and the reverse polarity charge is recirculated to the welding capacitor as a charge having the same polarity as the charge charge, and becomes a part of the charge charge in the next cycle.
- a capacitor welding method is proposed.
- a charging circuit having a reverse blocking function, a welding capacitor charged by electric power fed from the charging circuit, a discharge switch for discharging a charging charge of the welding capacitor, and a primary winding
- a welding transformer having a wire and a secondary winding; a first welding electrode connected to the secondary winding; and a second welding electrode; and when the discharge switch is turned on, Discharging the charged charge to the primary winding, passing a welding current through the secondary winding, the first electrode, and the second electrode to the workpiece;
- Capacitor-type welding apparatus for welding when opening between the first welding electrode and the second welding electrode in a state where an excitation current is flowing in the secondary winding of the welding transformer, Make the discharge switch ready to turn on And a surge voltage generated in the primary winding of the welding transformer when a gap between the first welding electrode and the second welding electrode is opened.
- a capacitor-type welding apparatus is proposed in which a surge current is passed through the discharge switch as a surge current through the discharge switch.
- the charge due to the surge current charged in the welding capacitor when the discharge switch is turned on again is a reverse polarity charge opposite to the polarity of the charge charge
- a capacitor-type welding apparatus wherein an energy recovery switch for flowing the reverse polarity charge to the welding capacitor as a charge having the same polarity as the charge charge is connected in parallel with a polarity opposite to the discharge switch. suggest.
- the present invention has a simple circuit configuration and can prevent the occurrence of afterflash when opening between welding electrodes through which an exciting current flows, and can prevent a large surge voltage from being generated in the primary winding. Can do.
- the capacitor-type welding method and welding apparatus have a discharge switch that is indispensable for discharging the charge charged in the welding capacitor through the primary winding of the welding transformer.
- This discharge switch is set so as to be in an ON state when the welding electrodes are opened while an exciting current is flowing between the secondary winding of the welding transformer and the welding electrodes.
- welding used in the present invention includes not only welding in which both metals melt and form a nugget due to heat generation at the welding location, but also diffusion bonding in which both metals are plastically fluidized and joined by heat generation at the welding location.
- symbol shall show the member of the same name.
- a pressurizing mechanism for applying pressure (forging pressure) or the first welding electrode 7 or the second welding electrode 8 to drive a welding current between the first welding electrode 7 and the second welding electrode 8 is driven. Illustrations of mechanisms that are not particularly necessary for describing the operation of the present invention, such as a drive mechanism and various detection circuits, are omitted.
- FIG. 1 A capacitor welding apparatus shown in FIG. 1 includes a charging circuit 1, a welding transformer 4 having a DC output terminal 2 and 3 of the charging circuit 1, a primary winding 4a and a secondary winding 4b, a welding capacitor 5, and a discharging capacitor.
- the switch 6 includes a first welding electrode 7 and a second welding electrode 8 connected to the secondary winding 4b, and a controller 10 that gives an ON signal to the discharge switch 6 via an insulation drive circuit 9.
- FIGS. 1 to 6 will be referred to as appropriate.
- W1 and W2 are objects to be welded that are disposed between the first welding electrode 7 and the second welding electrode 8 and are welded by applying a welding current in a pressurized state.
- An object to be welded after the welding current is applied and welding is referred to as a welded article.
- the capacitor welding apparatus shown in FIG. 1 has the advantage that the welding transformer 4 is difficult to be biased because the charging current and the discharging current of the welding capacitor 5 flow in the primary winding 4a of the welding transformer 4 in opposite directions. is there.
- the charging circuit 1 is a circuit for charging the welding capacitor 5, and the circuit configuration is not particularly limited. Although a specific circuit is not illustrated for the charging circuit 1, some examples will be briefly described.
- As the input power source a single-phase or three-phase commercial AC power source or a generator is used.
- the input power supply is single-phase AC power, it has an open / close function consisting of a single-phase full-wave rectifier circuit with a rectifier diode connected in a bridge configuration and a semiconductor switch such as a thyristor connected in series on the DC output side.
- the charging circuit 1 may be a charging circuit having a single-phase mixed bridge type full-wave rectifying circuit having an open / close function in which a rectifying diode and a thyristor are connected in a bridge configuration.
- a switching function comprising a three-phase full-wave rectifier circuit in which a rectifier diode is connected in a three-phase bridge configuration and a semiconductor switch connected in series on the DC output side
- a three-phase mixed bridge type full-wave rectifier circuit having a switching function in which a rectifier diode and a thyristor are connected in a three-phase bridge configuration may be used as the charging circuit 1.
- the charging circuit 1 After the welding capacitor 5 is discharged, the charging circuit 1 has a charging voltage due to vibration (resonance) composed of the combined inductance L having the leakage inductance of the welding transformer 4 and the inductance of the circuit and the capacitor C of the welding capacitor 5. Is not turned on with a reverse polarity voltage, that is, with an inverted voltage.
- a circuit configuration having an opening / closing function for blocking an inversion voltage is used.
- a thyristor is used for the positive or negative rectifier element of the charging rectifier circuit so that no gate signal is given after the end of charging.
- the series circuit of the primary winding 4 a of the welding transformer 4 and the welding capacitor 5 is connected in parallel between the DC output terminals 2 and 3 of the charging circuit 1.
- the welding transformer 4 has a secondary winding 4b of about one turn and a primary winding 4a having a larger number of turns than the secondary winding 4b.
- First and second welding electrodes 7 and 8 are connected to both ends of the secondary winding 4 b of the welding transformer 4. Since the first and second welding electrodes 7 and 8 may be general ones, description thereof is omitted.
- the welding capacitor 5 includes, for example, a block in which a plurality of polar electrolytic capacitors are connected in parallel, a capacitor bank in which a plurality of these blocks are connected in parallel, or a plurality of nonpolar (bipolar) polypropylene film capacitors, for example. Blocks connected in parallel or capacitor banks in which a plurality of these blocks are connected in parallel.
- the discharge switch 6 is connected in parallel to the series circuit of the primary winding 4 a of the welding transformer 4 and the welding capacitor 5. When the discharge switch 6 is turned on, a discharge circuit from the welding capacitor 5 is formed.
- a thyristor is used as the discharge switch 6. Therefore, in the following description of the first embodiment, the discharge switch 6 will be described as the discharge thyristor 6.
- the discharge thyristor 6 has an anode connected to the DC output terminal 2 of the charging circuit 1 and a cathode connected to the DC output terminal 3. During the period in which the charging circuit 1 charges the capacitor 5, the discharging thyristor 6 is turned off.
- the controller 10 gives a drive signal to the discharge switch 6 through the insulation drive circuit 9.
- the insulation drive circuit 9 insulates and transmits the gate signal from the controller 10 using, for example, a photocoupler, and generates the gate signal of the thyristor with a gate amplifier (not shown). Since the photocoupler and the gate amplifier may be general ones, detailed description thereof is omitted.
- the controller 10 provides a continuous drive signal between the gate and cathode of the discharge thyristor 6 through the insulated drive circuit 9 from time t1 to time t2 as shown in FIG.
- FIG. 2 is a diagram for explaining a state in which the discharging thyristor 6 is turned on and the charging charge of the welding capacitor 5 is discharged.
- FIG. 3 is a view for explaining a state in which the discharge thyristor 6 is turned off by discharging the charge of the welding capacitor 5.
- FIG. 4 is a view for explaining a state in which the space between the first welding electrode 7 and the second welding electrode 8 is opened in a state where the discharging thyristor 6 is turned off.
- FIG. 5 is a diagram for explaining a state in which the discharge thyristor 6 is turned on when the space between the first welding electrode 7 and the second welding electrode 8 is opened.
- FIG. 6 is a diagram showing a current waveform, a voltage waveform, and a drive signal waveform of each part.
- the charging circuit 1 having an opening / closing function is electrically disconnected from the DC output terminals 2 and 3.
- the discharging thyristor 6 is in an off state.
- a drive signal is given from the controller 10 to the discharging thyristor 6 through the insulated drive circuit 9 at time t1.
- the discharge thyristor 6 is turned on by the drive signal.
- a discharge current I ⁇ b> 1 due to the charge of the welding capacitor 5 flows through the primary winding 4 a of the welding transformer 4.
- the discharge current I1 mainly flows as the welding current I2 to the secondary winding 4b of the welding transformer 4, and a part of the discharge current I1 flows as the exciting current I3 to the primary winding 4a of the welding transformer 4.
- the discharge current I1 I2 / n + I3.
- the discharge thyristor 6 When the discharge thyristor 6 is turned on, a large and steep welding current I2 corresponding to the turns ratio of the primary winding 4a and the secondary winding 4b is applied to the first welding electrode 7, the workpieces W1 and W2, the second The welding electrode 8 flows. When the welding current I2 flows, the workpieces W1 and W2 are welded.
- the current waveform of the discharge current I1 becomes a sinusoidal waveform as shown in FIG. 6B. This sinusoidal waveform is caused by vibration (resonance) caused by a combined inductance L composed of a leakage inductance of the welding transformer 4 and a circuit inductance and a capacitor C of the welding capacitor 5.
- the pulse width of the current waveform of the discharge current I1 shown in FIG. 6 (B) does not actually exceed several hundred milliseconds, and is required for the mechanical operation of the first and second welding electrodes 7 and 8. Since it is shorter than the time, it is not necessary to consider the wave tail problem of the discharge current I1 in the present invention.
- the discharge thyristor 6 When the discharge thyristor 6 is turned on, the voltage of the capacitor 5 is reversed to the reverse polarity due to the vibration of the inductance L and the capacitor C.
- the discharge current I1 does not substantially flow through the discharge thyristor 6, that is, when the discharge current I1 becomes smaller than the holding current of the discharge thyristor 6, the discharge thyristor 6 is turned off by natural arc extinction.
- the welding capacitor 5 is charged with the opposite polarity to the charged charge, so the voltage of the welding capacitor 5 becomes the opposite polarity voltage ( ⁇ V2) shown in FIG. 6 (A) and FIG. . Since the charging circuit 1 having the opening / closing function is off, the reverse polarity voltage ( ⁇ V2) is held without being discharged.
- This reverse polarity voltage ( ⁇ V2) is a smaller value than the predetermined charging voltage (+ V1) by the charge.
- the primary side excitation current I3 flowing through the primary winding 4a shown in FIG. 2 cannot continue to flow through the primary winding 4a as it is, and is commutated to the secondary winding 4b.
- the secondary side exciting current I4 shown in FIG. This exciting current I4 flows in the direction opposite to the direction of the welding current I2 and flows through the first welding electrode 7, the workpieces W1, W2 and the second welding electrode 8 from the black dot side indicating the polarity of the secondary winding 4b. It flows to the non-black spot side of the next winding 4b.
- the workpieces W1 and W2 are already welded and become welded articles. Since the welded article has a resistance value smaller than that before welding and the resistance component in the circuit on the secondary side of the welding transformer 4 is made smaller, the exciting current I4 does not disappear in a short time. In order to improve the welding speed, the welding cycle is shortened. For this reason, during the period in which the excitation current I4 has not disappeared and is still flowing through the secondary circuit, the first welding electrode 7 and the second welding electrode 8 are mechanically moved in a direction away from each other, The space between the first welding electrode 7 and the second welding electrode 8 is opened.
- opening between the first welding electrode 7 and the second welding electrode 8 means that either the first welding electrode 7 or the second welding electrode 8 is separated from the welding article (W1, W2). Say, become electrically disconnected. It is assumed that the space between the first welding electrode 7 and the second welding electrode 8 is opened at time t2 in FIG.
- the discharge thyristor 6 is not in a state where it can be turned on when the surge voltage Vs1 is generated, a large surge voltage Vs1 generated in the primary winding 4a is applied between the anode and the cathode of the discharge thyristor 6. In this case, a thyristor having a large forward blocking characteristic must be used.
- a drive signal is applied to the gate of the discharge thyristor 6 at time t2 when the gap between the first welding electrode 7 and the second welding electrode 8 is opened. Therefore, at the same time as the surge voltage (+ Vs1) generated in the primary winding 4a exceeds the absolute value of the reverse polarity voltage ( ⁇ V2) of the welding capacitor 5, the discharging thyristor 6 is turned on again.
- a surge current I5 shown in FIG. 6 is supplied to the welding capacitor 5 through the discharge thyristor 6, and the welding capacitor 5 is charged to a voltage ( ⁇ V3). That is, the surge energy generated in the primary winding 4 a is absorbed by the welding capacitor 5 through the discharge thyristor 6.
- the voltage ( ⁇ V3) is almost the same as the voltage ( ⁇ V2).
- the first welding electrode 7 and the second welding are performed when the exciting current I4 of the welding transformer 4 flows through the first and second welding electrodes 7 and 8 and the welding article. Even if the electrode 8 is opened, a large surge voltage (+ Vs1) is not generated in the discharge thyristor 6. Assuming that the voltage of the welding capacitor 5 is ⁇ V2, the voltage of the discharging thyristor 6 is limited to the voltage ( ⁇ V2) of the welding capacitor 5. For this reason, the discharge thyristor 6 does not require a withstand voltage up to the high surge voltage Vs1. Let the winding ratio of the welding transformer 4 be n. A space between the first welding electrode 7 and the second welding electrode 8 is opened in a state where the exciting current I4 is flowing.
- the surge voltage generated between the first welding electrode 7 and the second welding electrode 8 is reduced to V2 / n. In this case, after-flash is unlikely to occur. Therefore, according to the first embodiment, there is no need to add a special circuit component when the gap between the welding electrodes is opened while the exciting current I4 is flowing between the welding electrodes. Further, since the surge voltage can be suppressed to a sufficiently small value without increasing the withstand voltage of the discharge thyristor 6, afterflash can be prevented. Note that the values of the voltage ( ⁇ V2) and the voltage ( ⁇ V3) of the welding capacitor 5 are naturally smaller than the value of the charging voltage (+ V1) due to circuit loss and the like.
- a welding capacitor 5 is connected in parallel between the DC output terminals 2 and 3.
- a series circuit of the primary winding 4 a of the welding transformer 4 and the discharge switch 6 is connected in parallel to the welding capacitor 5.
- the charging circuit 1 charges the welding capacitor 5 with a polarity such that the DC output terminal 2 side of the welding capacitor 5 is positive and the DC output terminal 3 side is negative.
- the charging current supplied from the charging circuit 1 to the welding capacitor 5 does not flow through the primary winding 4 a of the welding transformer 4. During the period in which the charging circuit 1 charges the welding capacitor 5, the discharging switch 6 is turned off.
- the energy recovery switch 11 connected in parallel with the discharge thyristor 6 in reverse polarity is used.
- a thyristor having reverse blocking characteristics is used as the discharge switch 6, and a thyristor is used as the energy recovery switch 11.
- the discharge switch 6 is described as the discharge thyristor 6 and the energy recovery switch 11 is described as the energy recovery thyristor 11.
- the first welding electrode 7 and the second welding electrode 8 are connected in parallel to the secondary winding of the welding transformer 4 as in FIG. Welding is performed by passing a welding current through the workpieces W1 and W2 sandwiched between the first welding electrode 7 and the second welding electrode 8.
- the controller 10 gives two driving signals Sa and Sb as shown in FIG. 8C to the discharging thyristor 6 through the insulating driving circuit 9.
- a drive signal Ss indicated by a broken line is given to the energy recovery thyristor 11.
- the controller 10 applies the drive signal Sa between the gate and the cathode of the discharge thyristor 6 through the insulated drive circuit 9 at time t1.
- the discharge thyristor 6 is turned on to discharge the charging charge of the welding capacitor 5, and a discharge current I 1 as shown in FIG. 8B flows through the primary winding 4 a of the welding transformer 4.
- the current waveform of the discharge current I1 is a sinusoidal waveform caused by vibration (resonance) including the inductance L of the inductance of the welding transformer 4 and the inductance of the circuit and the capacitor C of the welding capacitor 5.
- a discharge current and an excitation current flow through the primary winding 4a.
- the welding current flows from the black spot side of the secondary winding 4b to the non-black spot side of the secondary winding 4b through the first welding electrode 7, the workpieces W1 and W2, and the second welding electrode 8 to perform welding. .
- the welding capacitor 5 has a voltage ( ⁇ V2) having a polarity opposite to that of the charge when the discharge thyristor 6 is turned off. Charged. This reverse polarity voltage is a smaller value than the charge voltage (+ V1) by the charge.
- the discharging thyristor 6 is turned off, the excitation current flowing in the primary winding 4a is commutated to the secondary winding 4b as in the first embodiment.
- the exciting current flows from the non-black spot side of the secondary winding 4b to the black spot side of the secondary winding 4b through the second welding electrode 8, workpieces W2 and W1, and the first welding electrode 7. This excitation current flows through the secondary circuit without disappearing in a short time.
- the drive signal Sb is applied between the gate and cathode of the discharge thyristor 6 through the insulated drive circuit 9 from the controller 10. Therefore, the discharge thyristor 6 can be turned on at any time when the voltage on the anode side becomes larger than the voltage on the cathode side.
- the first and second welding electrodes 7 and 8 moves, and the first welding electrode 7 or the second welding electrode 8 moves away from the workpiece W1 or W2 and is not electrically connected. It becomes a state. Since the excitation current that has been flowing through the first and second welding electrodes 7 and 8 until immediately before time t2 can no longer flow through the secondary circuit after time t2, a surge voltage is generated in the primary winding 4a.
- This surge voltage is applied to the anode of the discharge thyristor 6 through the welding capacitor 5.
- the surge voltage exceeds the value of the voltage ( ⁇ V2) of the welding capacitor 5
- the discharging thyristor 6 is turned on and the surge voltage generated in the primary winding 4a is absorbed by the welding capacitor 5 as the surge current I5. . Therefore, a surge voltage substantially exceeding the voltage ( ⁇ V2) is not applied between the anode and cathode of the discharge thyristor 6. Therefore, it is possible to prevent the occurrence of after flash when the welding electrodes are opened.
- the discharge thyristor 6 is turned on, and after the surge energy is absorbed by the welding capacitor 5, the discharge thyristor 6 is turned off.
- the controller 10 supplies the drive signal Ss to the energy recovery thyristor 11 through the insulated drive circuit 9 to turn it on.
- the welding capacitor 5 is charged to a voltage at which the DC output terminal 3 is positive with respect to the DC output terminal 2 at this time. Therefore, the electric charge vibrates with the circuit inductance through the energy recovery thyristor 11, and the DC output terminal 2 charges the welding capacitor 5 with a positive polarity with respect to the DC output terminal 3.
- This charging is the same as the polarity (positive polarity) of the charging charge charged by the charging circuit 1 and the surge energy is also superimposed, so that the next charging time can be further shortened and power saving can be achieved. Further, since the inrush current is less likely to flow at the start of the next charging by the voltage, the burden on the charging circuit 1 can be reduced.
- the workpieces W1 and W2 are made of a highly conductive metal material having a low resistivity such as copper or aluminum, a rapidly increasing pulse-shaped welding current is used, and the workpieces W1 and W2 are used. It is effective to use a welding method in which the responsiveness of the applied pressure to is high. For this reason, the energy of the voltage ( ⁇ V2) charged to the welding capacitor 5 with the reverse polarity tends to increase. In this case, it is preferable to use a nonpolar film capacitor using a polypropylene film or the like as a dielectric rather than using a polar electrolytic capacitor as the welding capacitor 5. By doing in this way, big energy can be collect
- the drive signal applied to the discharge thyristor 6 is shown in FIG.
- the driving signal for the discharging thyristor 6 is given at time t1 when the charging charge charged in the welding capacitor 5 is discharged, and thereafter, the first welding electrode 7 and the second welding electrode 8 are opened. It is given at least until time t2. That is, a continuous drive signal is given to the discharge thyristor 6.
- the drive signal applied to the discharge thyristor 6 is shown in FIG. After the drive signal Sa is given at the time t1 when the charge charged in the welding capacitor 5 is discharged, the drive signal is no longer given to the discharge thyristor 6.
- the drive signal Sb is applied to at least the discharge thyristor 6 immediately before time t2 when the gap between the first welding electrode 7 and the second welding electrode 8 is opened. That is, the discharge thyristor 6 is given a drive signal that is interrupted halfway.
- a driving signal similar to that in the second embodiment may be applied to the discharging thyristor 6, and in the second embodiment, a driving signal similar to that in the first embodiment may be applied to the discharging thyristor 6. Good.
- the discharge switch 6 and the energy recovery thyristor 11 according to the first and second embodiments described above, a bipolar transistor having reverse blocking characteristics, or a semiconductor switch such as IGBT or MOSFET may be used in addition to the thyristor.
- a bidirectional semiconductor switch having a bidirectional on / off function may be used as the discharge switch 6, and the bidirectional semiconductor switch may function as both the discharge switch 6 and the energy recovery thyristor 11.
- the insulating drive circuit 9 has been described as a photocoupler.
- an insulating transformer may be used.
- a circuit in which the resistance means and the diode are connected in series may be connected in parallel to the welding capacitor 5 in the first and second embodiments.
- the reverse polarity charge exhibiting the reverse polarity voltage (-V2) of the welding capacitor 5 can be discharged. That is, since the reverse polarity energy is consumed by the series circuit of the resistance means and the diode, the reverse polarity voltage ( ⁇ V2) can be lowered.
- the reverse polarity voltage ( ⁇ V2) can be set to approximately zero volts.
- the surge voltage caused by the exciting current of the welding transformer 4 can be suppressed to, for example, almost zero volts, and the afterflash can be further reduced. It can be surely prevented.
- a thyristor or a semiconductor switch can be used instead of the diode.
- the discharge switch 6 of the first embodiment described above may be used as the first discharge thyristor, and the second discharge thyristor may be connected in reverse parallel to the first discharge thyristor.
- the electric charge accumulated in the welding capacitor 5 can be discharged using the first discharge thyristor and the second discharge thyristor.
- the first discharging thyristor 6 is turned on.
- the positive charge is discharged by the positive voltage of the welding capacitor 5, that is, the voltage (+ V1) of the welding capacitor 5 shown in FIG.
- the second discharge thyristor is then turned on.
- the reverse polarity voltage charged in the welding capacitor 5 by the discharge of the positive charge that is, the charge having the polarity voltage ( ⁇ V2) of the welding capacitor 5 shown in FIG. 3 is discharged. Due to the discharge of the polarity voltage ( ⁇ V2) of the welding capacitor 5, the welding capacitor 5 is again a positive voltage, that is, a voltage having the same polarity as the voltage (+ V1) in FIG. Is charged to a low voltage.
- the second discharge thyristor is not turned on when the discharge current of the welding capacitor flowing through the first discharge thyristor becomes substantially non-flowing due to natural arc extinction. Shall.
- the excitation current of the primary winding of the welding transformer 4 flowing in the direction of I3 in FIG. 2 is converted as the excitation current of the secondary winding in the direction of I4 in FIG. Shed.
- the surge voltage generated when the space between the first welding electrode 7 and the second welding electrode 8 is opened in the state where the exciting current of the secondary winding flows in the direction of I4 is shown in FIG. It has the same polarity as Vs1 and Vs2.
- the first discharge thyristor can be turned on, and the surge voltage caused by the exciting current of the welding transformer 4 can be absorbed by the welding capacitor 5.
- a semiconductor switch may be used instead of the second discharge thyristor used as the discharge switch.
- the discharge current of the welding capacitor flowing through the second discharge thyristor is in a state in which the second discharge thyristor does not substantially flow due to natural arc extinction.
- the first discharging thyristor is not turned on again.
- the exciting current of the primary winding of the welding transformer which was flowing in the direction opposite to I3 in FIG. 2, is opposite to that of I4 in FIG. 3 as the exciting current of the secondary winding. Commutation. For this reason, the surge voltage generated when the space between the first welding electrode 7 and the second welding electrode 8 is opened while the excitation current of the secondary winding flows in the direction opposite to I4 in FIG.
- Vs1 and Vs2 shown in FIG. 4 The opposite polarity to Vs1 and Vs2 shown in FIG. 4, that is, the black spots of the primary and secondary windings of the welding transformer have a negative polarity. Therefore, the second discharge thyristor is turned on, and the surge voltage generated in the primary winding is caused to flow as a surge current to the welding capacitor 5 through the second discharge thyristor. The resulting surge voltage can be absorbed by the welding capacitor 5.
- a diode or a semiconductor switch may be used instead of the second discharge thyristor used as the discharge switch.
- the energy recovery thyristor 11 connected in antiparallel to the discharge switch 6 shown in FIG. 7 can also be used as the above-described second discharge thyristor. In this case, the energy recovery thyristor 11 is also included in the discharge switch.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Generation Of Surge Voltage And Current (AREA)
Abstract
[Problem] To prevent, with a simple circuit configuration, an after-flash from occurring and a large surge voltage from occurring in a primary winding when opening between welding electrodes between which excitation current is flowing. [Solution] In a capacitor type welding method according to the present invention, electric charges charged on a welding capacitor are discharged and when the discharge current is brought into a state in which the discharge current does not substantially flow through a discharge switch, excitation current that has been flowing through the primary winding of a welding transformer is transferred to the secondary winding thereof. When opening between a first welding electrode and a second welding electrode while the transferred excitation current is flowing through the secondary winding, the discharge switch is brought into a state in which the discharge switch can be turned on by applying a drive signal thereto. Surge voltage occurring in the primary winding of the welding transformer when opening between the first and second welding electrodes is thereby flowed through the discharge switch to the welding capacitor as surge current.
Description
この発明は、充電回路により溶接用コンデンサに蓄えたエネルギーを溶接トランスを介して短時間で溶接電極間に放電することによって被溶接物を溶接するコンデンサ式溶接方法及び溶接装置に関する。
The present invention relates to a capacitor type welding method and a welding apparatus for welding an object to be welded by discharging energy stored in a welding capacitor by a charging circuit between welding electrodes in a short time via a welding transformer.
コンデンサ式溶接装置は、放電時間に比べて長い時間をかけて溶接用コンデンサに溶接電力を蓄え、それを短時間で一気に放電する。このため、一般的な交流溶接装置に比べて、受電設備が大容量化しないという設備面での利点がある。また、被溶接物に対して加熱する度合いが小さいので、溶接箇所での溶接痕(焼け)がほとんど無く、また歪なども小さいという利点を有する。コンデンサ式溶接装置は、小型から大型までの産業設備で広く採用されている。
The capacitor-type welding device stores welding power in the welding capacitor over a long time compared to the discharge time, and discharges it at once in a short time. For this reason, compared with a general alternating current welding apparatus, there is an advantage in terms of equipment that the power receiving equipment does not increase in capacity. In addition, since the degree to which the workpiece is heated is small, there are almost no weld marks (burns) at the welding location, and there is an advantage that distortion and the like are small. Capacitor-type welding equipment is widely used in small to large industrial equipment.
コンデンサ式溶接装置は、一般的に多数の電解コンデンサを並列に接続したコンデンサバンクを溶接用コンデンサとして用いる(例えば、特許文献1参照)。コンデンサ式溶接装置は、溶接電極間に被溶接物を配置した後、溶接電極間の間隔を狭め、溶接電極で被溶接物に所定の加圧力(鍛圧)を与える。このような機械的動作を行いながら、並行して溶接用コンデンサを充電する。溶接用コンデンサの充電電圧が所定値まで上昇すると、充電回路をオフにし、溶接電極が被溶接物に加圧力を与えた状態で、放電用スイッチをオンさせる。放電用スイッチがオンすると、溶接トランスの1次巻線には急峻に増大するパルス状の電流が流れる。溶接トランスの2次巻線は1ターン程度であり、1次巻線の巻数よりも大幅に少ないため、2次巻線には1次側電流よりも大幅に大きなパルス状の溶接電流が流れる。この溶接電流によって被溶接物を溶接し、短時間で溶接物品を得ることができる。
The capacitor type welding apparatus generally uses a capacitor bank in which a large number of electrolytic capacitors are connected in parallel as a welding capacitor (for example, see Patent Document 1). In the capacitor-type welding apparatus, after the workpiece is arranged between the welding electrodes, the interval between the welding electrodes is narrowed, and a predetermined pressure (forging pressure) is applied to the workpiece by the welding electrode. While performing such a mechanical operation, the welding capacitor is charged in parallel. When the charging voltage of the welding capacitor rises to a predetermined value, the charging circuit is turned off, and the discharging switch is turned on while the welding electrode applies pressure to the workpiece. When the discharge switch is turned on, a steeply increasing pulsed current flows through the primary winding of the welding transformer. Since the secondary winding of the welding transformer is about one turn and is significantly less than the number of turns of the primary winding, a pulsed welding current that is significantly larger than the primary current flows in the secondary winding. The welding object can be welded by this welding current, and a welded article can be obtained in a short time.
従来のコンデンサ式溶接装置では、溶接用コンデンサの放電回路の回路定数などによって放電電流、つまり溶接電流の波尾が長くなるものがある。波尾の長い溶接電流が流れるコンデンサ式溶接装置では、短い周期で溶接を行う場合、溶接電極の機械的な動作時間を考慮して、溶接結果に影響を及ぼさない溶接電流の波尾をカットする。つまり、小さい溶接電流が、溶接電極間をまだ流れているときに、溶接電極間が開く方向に溶接電極を移動させることで溶接周期を短くしている。
Some conventional capacitor-type welding apparatuses have a longer discharge current, that is, a wave tail of the welding current, depending on the circuit constant of the discharge circuit of the welding capacitor. Capacitor-type welding equipment that has a long wave tail welding current cuts the wave tail of the welding current that does not affect the welding result in consideration of the mechanical operation time of the welding electrode when welding is performed in a short cycle. . That is, when a small welding current is still flowing between the welding electrodes, the welding cycle is shortened by moving the welding electrodes in a direction in which the welding electrodes are opened.
この場合、溶接トランスの2次巻線で溶接電流の波尾部分が流れているときに2次巻線間を開放すると、1次巻線間に大きな電圧が誘起されると同時に、溶接電極と被溶接物との間にアフターフラッシュと称されるスパークが発生し、被溶接物に傷をつけてしまうという問題がある。このアフターフラッシュの問題を解決する考案が既に提案されている(例えば、特許文献2参照)。特許文献2では、アフターフラッシュを防止するために、溶接トランスの1次巻線間に、ダイオードとインピーダンスとを直列に接続した一方向インピーダンス回路を用いている。この一方向インピーダンス回路は、溶接電流の波尾部分が溶接電極間を流れている状態で、溶接電極間を開放する際に発生するアフターフラッシュを防止するには有効な手段である。
In this case, if the secondary winding is opened while the welding current wave tail is flowing in the secondary winding of the welding transformer, a large voltage is induced between the primary windings, There is a problem that a spark called after flash occurs between the workpiece and the workpiece to be welded. A device for solving the problem of the afterflash has already been proposed (see, for example, Patent Document 2). In Patent Document 2, a one-way impedance circuit in which a diode and an impedance are connected in series is used between primary windings of a welding transformer in order to prevent afterflash. This one-way impedance circuit is an effective means for preventing afterflash that occurs when the welding electrodes are opened between the welding electrodes in a state in which the wave tail portion of the welding current flows between the welding electrodes.
一方、本発明のコンデンサ式溶接方法及び溶接装置は、回路内のインダクタンス成分と溶接用コンデンサなどのキャパシタ成分との振動(共振)を利用する。インダクタンス成分とキャパシタ成分との振動動作によって、溶接用コンデンサの放電電流波形は正弦波状に近い波形となるので、溶接周期に影響を与えるような長い波尾は生じない。したがって、本発明では、溶接周期を短くする場合において、溶接電流の波尾は特に考慮する必要がない。ところが、溶接トランスの励磁電流が問題となることが分かったので、この励磁電流に起因する問題を解決する。
On the other hand, the capacitor welding method and welding apparatus of the present invention utilize vibration (resonance) between an inductance component in a circuit and a capacitor component such as a welding capacitor. Due to the vibration operation of the inductance component and the capacitor component, the discharge current waveform of the welding capacitor becomes a waveform close to a sine wave, so that a long wave tail that affects the welding cycle does not occur. Therefore, in the present invention, when shortening the welding cycle, it is not necessary to consider the wave tail of the welding current. However, since it has been found that the exciting current of the welding transformer becomes a problem, the problem caused by this exciting current is solved.
溶接用コンデンサが放電される際の溶接トランスの励磁電流については後に詳述するので、ここでは簡単に述べる。放電用スイッチがオンし、溶接用コンデンサの充電電圧が溶接トランスの1次巻線に加わっているとき、1次巻線に励磁電流が流れる。この1次巻線に励磁電流が流れている状態で、放電用スイッチがオフすると、1次巻線を流れていた励磁電流は溶接トランスの2次巻線に転流し、2次巻線及び溶接電極を通して還流する。なお、この2次巻線に励磁電流が転流しているときは、溶接用コンデンサの充電電荷の放電に伴う溶接電流は既に消滅しており、2次巻線を流れていない。一般的に、溶接が終わった後の溶接電極間のインピーダンスは非常に小さく、溶接トランスの2次側の回路の抵抗成分は小さくなるように製作されている。このため、溶接電流が消滅してから数秒以内に、励磁電流が溶接トランスの2次側の回路内で消費されることによって消滅することはほとんど無い。
The excitation current of the welding transformer when the welding capacitor is discharged will be described in detail later and will be briefly described here. When the discharge switch is turned on and the charging voltage of the welding capacitor is applied to the primary winding of the welding transformer, an exciting current flows through the primary winding. If the discharge switch is turned off while the exciting current is flowing in the primary winding, the exciting current flowing in the primary winding is commutated to the secondary winding of the welding transformer, and the secondary winding and the welding Reflux through electrode. When the excitation current is commutated in the secondary winding, the welding current accompanying the discharge of the charging charge of the welding capacitor has already disappeared and does not flow through the secondary winding. Generally, the impedance between the welding electrodes after the welding is finished is very small, and the resistance component of the circuit on the secondary side of the welding transformer is made small. For this reason, the exciting current hardly disappears by being consumed in the secondary circuit of the welding transformer within a few seconds after the welding current disappears.
したがって、インダクタンス成分と溶接用コンデンサなどのキャパシタ成分との振動を利用するコンデンサ式溶接では、溶接周期を非常に長くしない限り、励磁電流が2次巻線から溶接電極間を流れている状態で、溶接電極間を開放することになる。2次巻線に励磁電流が流れる状態で溶接電極間を開放すると、励磁電流によるアフターフラッシュが生じると共に、溶接トランスの1次巻線に非常に大きなサージ電圧が発生する。よって、アフターフラッシュによる傷が生じやすく、無い高品質の溶接物品を得るのは困難となっていた。また、耐圧の大きなサイリスタなどの放電用スイッチを用いなければならないためコストアップの原因となっていた。
Therefore, in capacitor type welding using the vibration between the inductance component and a capacitor component such as a welding capacitor, unless the welding cycle is very long, the excitation current flows between the secondary winding and the welding electrode. The space between the welding electrodes will be opened. If the welding electrodes are opened in the state where the excitation current flows through the secondary winding, afterflash occurs due to the excitation current and a very large surge voltage is generated in the primary winding of the welding transformer. Therefore, it is difficult to obtain a high-quality welded article that is easily damaged by afterflash and is free of defects. In addition, a discharge switch such as a thyristor with a high withstand voltage must be used, which causes an increase in cost.
特許文献1には、コンデンサ式溶接機が記載されているが、溶接トランスの2次巻線から溶接電極間に電流が流れているときに溶接電極間を開放することは勿論のこと、そのときの問題点などについても記述されていない。特許文献1に記載される発明では、溶接トランスの2次巻線から溶接電極間に電流が流れているときに溶接電極間を開放するとアフターフラッシュが生じ、1次巻線には大きなサージ電圧が発生する。このため、耐圧の大きな放電用スイッチや充電回路などを用いなければならない。
Patent Document 1 describes a capacitor-type welder, but when a current is flowing between the welding winding and the secondary winding of the welding transformer, the welding electrodes are opened, of course, There is no description about the problems. In the invention described in Patent Document 1, after current is released between the secondary windings of the welding transformer and the welding electrodes are opened, afterflash occurs, and a large surge voltage is generated in the primary winding. appear. For this reason, it is necessary to use a discharge switch or a charging circuit having a high withstand voltage.
特許文献2に記載される考案は、充電電流の波尾が長い場合において、溶接周期を短縮するときに発生するアフターフラッシュを防止するためのものである。この対策として、ダイオードとインピーダンスとを直列接続してなる一方向インピーダンス回路を新たに備えている。しかし、特許文献2には、溶接トランスの1次巻線に流れていた励磁電流が2次巻線に転流して流れる動作や、励磁電流が2次巻線に流れているときに溶接電極間を開放した場合の問題及びその問題を解決する方法や手段については記述されていない。
The idea described in Patent Document 2 is to prevent after-flash that occurs when the welding cycle is shortened when the wave current of the charging current is long. As a countermeasure against this, a one-way impedance circuit is newly provided by connecting a diode and an impedance in series. However, Patent Document 2 discloses an operation in which the excitation current flowing in the primary winding of the welding transformer commutates to the secondary winding, or between the welding electrodes when the excitation current flows in the secondary winding. There is no description of the problem of opening and the method and means for solving the problem.
本発明は、励磁電流が流れている状態で溶接電極間を開放するときには、溶接用コンデンサの充電電荷を放電するための放電用スイッチがオン状態にあるように設定する。励磁電流が流れている溶接電極間を開放するときにアフターフラッシュが発生したり、1次巻線にサージ電圧が発生したりするのを防止することができる。
In the present invention, when the welding electrodes are opened in the state where the exciting current is flowing, the discharging switch for discharging the charging charge of the welding capacitor is set to be on. It is possible to prevent an after flash from occurring when opening the welding electrodes through which an exciting current flows, or a surge voltage from being generated in the primary winding.
第1の発明は、充電回路から給電される電力によって溶接用コンデンサを充電し、放電用スイッチをオンして前記溶接用コンデンサに充電された充電電荷を溶接トランスの1次巻線に放電し、前記溶接トランスの2次巻線及び該2次巻線に接続された第1の溶接電極と第2の溶接電極とを通して溶接電流を被溶接物に通電して該被溶接物を溶接するコンデンサ式溶接方法であって、前記溶接用コンデンサに充電された前記充電電荷を放電して、放電電流が前記放電用スイッチを通して実質的に流れない状態になると、前記溶接トランスの前記1次巻線を流れていた励磁電流は前記2次巻線に転流し、前記2次巻線に前記励磁電流が流れている状態で前記第1の溶接電極と前記第2の溶接電極との間を開放するときには、駆動信号を与えて前記放電用スイッチをオンできる状態にし、前記第1の溶接電極と前記第2の溶接電極との間を開放するときに前記溶接トランスの前記1次巻線に生じるサージ電圧を前記放電用スイッチを通して前記溶接用コンデンサにサージ電流として流すことを特徴とするコンデンサ式溶接方法を提案する。
The first invention charges the welding capacitor with the electric power fed from the charging circuit, turns on the discharge switch, and discharges the charging charge charged in the welding capacitor to the primary winding of the welding transformer, Capacitor type in which a welding current is passed through a workpiece through a secondary winding of the welding transformer and a first welding electrode and a second welding electrode connected to the secondary winding to weld the workpiece. In the welding method, when the charging charge charged in the welding capacitor is discharged and a discharge current is not substantially passed through the discharging switch, the welding current flows through the primary winding of the welding transformer. The excitation current that has been commutated to the secondary winding, and when the gap between the first welding electrode and the second welding electrode is opened in a state where the excitation current is flowing in the secondary winding, Before giving drive signal When the discharge switch is turned on, the surge voltage generated in the primary winding of the welding transformer when the gap between the first welding electrode and the second welding electrode is opened through the discharge switch. We propose a capacitor-type welding method characterized by flowing a surge current through a welding capacitor.
第2の発明は、前記第1の発明において、前記駆動信号は連続する信号又は高周波で断続する信号であり、前記駆動信号は、前記溶接用コンデンサに充電された充電電荷を放電するときに前記半導体スイッチに与えられ、その後、前記第1の溶接電極と前記第2の溶接電極との間を開放するときまで少なくとも前記半導体スイッチに与えられていることを特徴とするコンデンサ式溶接方法を提案する。
According to a second invention, in the first invention, the drive signal is a continuous signal or a signal that is intermittent at a high frequency, and the drive signal discharges the charge charged in the welding capacitor. Proposed is a capacitor-type welding method which is applied to a semiconductor switch and then applied to at least the semiconductor switch until the gap between the first welding electrode and the second welding electrode is opened. .
第3の発明は、前記第1の発明において、前記駆動信号は連続する信号又は高周波で断続する信号であり、前記駆動信号は、前記溶接用コンデンサに充電された充電電荷を放電するときに前記半導体スイッチに与えられた後、前記駆動信号は前記半導体スイッチから除去され、前記第1の溶接電極と前記第2の溶接電極との間を開放する直前には少なくとも前記半導体スイッチに再び与えられることを特徴とするコンデンサ式溶接方法を提案する。
According to a third invention, in the first invention, the drive signal is a continuous signal or a signal that is intermittent at a high frequency, and the drive signal discharges the charge charged in the welding capacitor. After being applied to the semiconductor switch, the drive signal is removed from the semiconductor switch and applied again to at least the semiconductor switch immediately before opening the gap between the first welding electrode and the second welding electrode. We propose a capacitor welding method characterized by
第4の発明は、前記第1の発明から前記第3の発明のいずれかにおいて、前記放電用スイッチの再度のオンによって前記溶接用コンデンサに充電される前記サージ電流による電荷は前記充電電荷の極性と逆の逆極性電荷であり、その逆極性電荷は前記充電電荷と同極性の電荷として前記溶接用コンデンサに還流されて充電され、次の周期の前記充電電荷の一部分になることを特徴とするコンデンサ式溶接方法を提案する。
According to a fourth invention, in any one of the first to third inventions, the charge due to the surge current charged in the welding capacitor when the discharge switch is turned on again is the polarity of the charge charge. The reverse polarity charge is opposite to the charge charge, and the reverse polarity charge is recirculated to the welding capacitor as a charge having the same polarity as the charge charge, and becomes a part of the charge charge in the next cycle. A capacitor welding method is proposed.
第5の発明は、逆阻止機能を有する充電回路と、その充電回路から給電される電力によって充電される溶接用コンデンサと、前記溶接用コンデンサの充電電荷を放電する放電用スイッチと、1次巻線と2次巻線とを有する溶接トランスと、前記2次巻線に接続された第1の溶接電極と第2の溶接電極とを備え、前記放電用スイッチがオンするとき前記溶接用コンデンサの前記充電電荷を前記1次巻線に放電し、前記2次巻線及び前記第1の電極と前記第2の電極とを介して溶接電流を被溶接物に通電して、該被溶接物を溶接するコンデンサ式溶接装置であって、前記溶接トランスの前記2次巻線に励磁電流が流れている状態で前記第1の溶接電極と前記第2の溶接電極との間を開放するときに、前記放電用スイッチをオンできる状態にするための駆動信号を前記放電用スイッチに与えるコントローラを備え、前記第1の溶接電極と前記第2の溶接電極との間を開放するときに、前記溶接トランスの前記1次巻線に生じるサージ電圧を前記放電用スイッチを通して前記溶接用コンデンサにサージ電流として流すことを特徴とするコンデンサ式溶接装置を提案する。
According to a fifth aspect of the present invention, there is provided a charging circuit having a reverse blocking function, a welding capacitor charged by electric power fed from the charging circuit, a discharge switch for discharging a charging charge of the welding capacitor, and a primary winding A welding transformer having a wire and a secondary winding; a first welding electrode connected to the secondary winding; and a second welding electrode; and when the discharge switch is turned on, Discharging the charged charge to the primary winding, passing a welding current through the secondary winding, the first electrode, and the second electrode to the workpiece; Capacitor-type welding apparatus for welding, when opening between the first welding electrode and the second welding electrode in a state where an excitation current is flowing in the secondary winding of the welding transformer, Make the discharge switch ready to turn on And a surge voltage generated in the primary winding of the welding transformer when a gap between the first welding electrode and the second welding electrode is opened. A capacitor-type welding apparatus is proposed in which a surge current is passed through the discharge switch as a surge current through the discharge switch.
第6の発明は、前記第5の発明において、前記放電用スイッチの再度のオンによって前記溶接用コンデンサに充電される前記サージ電流による電荷は前記充電電荷の極性と逆の逆極性電荷であり、該逆極性電荷を前記充電電荷と同極性の電荷として前記溶接用コンデンサに流すエネルギー回収用スイッチが、前記放電用スイッチと逆の極性で並列に接続されることを特徴とするコンデンサ式溶接装置を提案する。
In a sixth aspect based on the fifth aspect, the charge due to the surge current charged in the welding capacitor when the discharge switch is turned on again is a reverse polarity charge opposite to the polarity of the charge charge, A capacitor-type welding apparatus, wherein an energy recovery switch for flowing the reverse polarity charge to the welding capacitor as a charge having the same polarity as the charge charge is connected in parallel with a polarity opposite to the discharge switch. suggest.
本発明は、簡単な回路構成で、励磁電流が流れている溶接電極間を開放するときにアフターフラッシュが発生するのを防止でき、1次巻線に大きなサージ電圧が発生するのを防止することができる。
The present invention has a simple circuit configuration and can prevent the occurrence of afterflash when opening between welding electrodes through which an exciting current flows, and can prevent a large surge voltage from being generated in the primary winding. Can do.
本発明に係るコンデンサ式溶接方法及び溶接装置は、溶接用コンデンサに充電された充電電荷を溶接トランスの1次巻線を通して放電するために必要不可欠な放電用スイッチを有する。この放電用スイッチを、溶接トランスの2次巻線から溶接電極間に励磁電流が流れている状態で溶接用電極間を開放するときに、オン状態にあるように設定する。これにより、溶接トランスの励磁電流が流れている溶接電極間を開放するときにアフターフラッシュが発生したり、1次巻線にサージ電圧が発生したりするのを防止することができる。
The capacitor-type welding method and welding apparatus according to the present invention have a discharge switch that is indispensable for discharging the charge charged in the welding capacitor through the primary winding of the welding transformer. This discharge switch is set so as to be in an ON state when the welding electrodes are opened while an exciting current is flowing between the secondary winding of the welding transformer and the welding electrodes. As a result, it is possible to prevent the occurrence of afterflash or the occurrence of a surge voltage in the primary winding when opening between the welding electrodes through which the exciting current of the welding transformer flows.
添付の図面を参照して本発明の実施形態を説明する。以下に示す実施形態によって、本発明は限定されるものではなく、本発明の技術思想から逸脱しない限り、本発明に含まれるものとする。本発明で用いる溶接という用語は、溶接箇所の発熱により双方の金属が溶融してナゲットを形成する溶接だけではなく、溶接箇所の発熱により双方の金属が塑性流動化して接合する拡散接合も含む。なお、本明細書及び図面において、符号が同じ構成要素は同一の名称の部材を示すものとする。第1の溶接電極7と第2の溶接電極8との間に溶接電流を流すために加圧力(鍛圧)を与える加圧機構や第1の溶接電極7又は第2の溶接電極8を駆動する駆動機構、各種の検出回路など、本発明の動作を説明する上で特に必要とならない機構については図示を省略する。
Embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the embodiments described below, and is included in the present invention without departing from the technical idea of the present invention. The term “welding” used in the present invention includes not only welding in which both metals melt and form a nugget due to heat generation at the welding location, but also diffusion bonding in which both metals are plastically fluidized and joined by heat generation at the welding location. In addition, in this specification and drawing, the component with the same code | symbol shall show the member of the same name. A pressurizing mechanism for applying pressure (forging pressure) or the first welding electrode 7 or the second welding electrode 8 to drive a welding current between the first welding electrode 7 and the second welding electrode 8 is driven. Illustrations of mechanisms that are not particularly necessary for describing the operation of the present invention, such as a drive mechanism and various detection circuits, are omitted.
[実施形態1]
図1~図6によって本発明に係る実施形態1の溶接方法及びコンデンサ式溶接装置について説明する。図1に示すコンデンサ式溶接装置は、充電回路1、充電回路1の直流出力端子2と3、1次巻線4aと2次巻線4bとを有する溶接トランス4、溶接用コンデンサ5、放電用スイッチ6、2次巻線4bに接続されている第1の溶接電極7と第2の溶接電極8、放電用スイッチ6に絶縁駆動回路9を介してオン信号を与えるコントローラ10で構成される。なお、本実施形態1の説明においては、図1~図6を適宜参照することとする。 [Embodiment 1]
The welding method and capacitor type welding apparatus according to the first embodiment of the present invention will be described with reference to FIGS. A capacitor welding apparatus shown in FIG. 1 includes a chargingcircuit 1, a welding transformer 4 having a DC output terminal 2 and 3 of the charging circuit 1, a primary winding 4a and a secondary winding 4b, a welding capacitor 5, and a discharging capacitor. The switch 6 includes a first welding electrode 7 and a second welding electrode 8 connected to the secondary winding 4b, and a controller 10 that gives an ON signal to the discharge switch 6 via an insulation drive circuit 9. In the description of the first embodiment, FIGS. 1 to 6 will be referred to as appropriate.
図1~図6によって本発明に係る実施形態1の溶接方法及びコンデンサ式溶接装置について説明する。図1に示すコンデンサ式溶接装置は、充電回路1、充電回路1の直流出力端子2と3、1次巻線4aと2次巻線4bとを有する溶接トランス4、溶接用コンデンサ5、放電用スイッチ6、2次巻線4bに接続されている第1の溶接電極7と第2の溶接電極8、放電用スイッチ6に絶縁駆動回路9を介してオン信号を与えるコントローラ10で構成される。なお、本実施形態1の説明においては、図1~図6を適宜参照することとする。 [Embodiment 1]
The welding method and capacitor type welding apparatus according to the first embodiment of the present invention will be described with reference to FIGS. A capacitor welding apparatus shown in FIG. 1 includes a charging
W1とW2とは、第1の溶接電極7と第2の溶接電極8との間に配置され、加圧された状態で溶接電流が通電されることにより溶接される被溶接物である。溶接電流が通電して溶接が行われた後の被溶接物を溶接物品という。図1に示すコンデンサ式溶接装置は、溶接用コンデンサ5の充電電流と放電電流とが溶接トランス4の1次巻線4aを互いに逆方向に流れるので、溶接トランス4が偏励磁され難いという利点がある。
W1 and W2 are objects to be welded that are disposed between the first welding electrode 7 and the second welding electrode 8 and are welded by applying a welding current in a pressurized state. An object to be welded after the welding current is applied and welding is referred to as a welded article. The capacitor welding apparatus shown in FIG. 1 has the advantage that the welding transformer 4 is difficult to be biased because the charging current and the discharging current of the welding capacitor 5 flow in the primary winding 4a of the welding transformer 4 in opposite directions. is there.
充電回路1は、溶接用コンデンサ5を充電するための回路であり、回路構成は特に限定されない。充電回路1について具体的な回路を図示しないが、幾つかの例を簡単に述べる。入力電源としては、単相もしくは三相の商用交流電源、又は発電機などが用いられる。入力電源が単相交流電力である場合には、整流用ダイオードをブリッジ構成に接続した単相全波整流回路とその直流出力側に直列接続されたサイリスタのような半導体スイッチとからなる開閉機能を有する充電回路、又は整流用ダイオードとサイリスタとをブリッジ構成に接続した開閉機能を有する単相の混合ブリッジ形全波整流回路などを充電回路1として用いてもよい。また、入力電源が三相交流電力である場合には、整流用ダイオードを三相ブリッジ構成に接続した三相全波整流回路とその直流出力側に直列接続された半導体スイッチとを備えた開閉機能を有する充電回路、又は整流用ダイオードとサイリスタとを三相ブリッジ構成に接続した開閉機能を有する三相の混合ブリッジ形全波整流回路などを充電回路1として用いてもよい。
The charging circuit 1 is a circuit for charging the welding capacitor 5, and the circuit configuration is not particularly limited. Although a specific circuit is not illustrated for the charging circuit 1, some examples will be briefly described. As the input power source, a single-phase or three-phase commercial AC power source or a generator is used. When the input power supply is single-phase AC power, it has an open / close function consisting of a single-phase full-wave rectifier circuit with a rectifier diode connected in a bridge configuration and a semiconductor switch such as a thyristor connected in series on the DC output side. The charging circuit 1 may be a charging circuit having a single-phase mixed bridge type full-wave rectifying circuit having an open / close function in which a rectifying diode and a thyristor are connected in a bridge configuration. In addition, when the input power supply is three-phase AC power, a switching function comprising a three-phase full-wave rectifier circuit in which a rectifier diode is connected in a three-phase bridge configuration and a semiconductor switch connected in series on the DC output side Or a three-phase mixed bridge type full-wave rectifier circuit having a switching function in which a rectifier diode and a thyristor are connected in a three-phase bridge configuration may be used as the charging circuit 1.
充電回路1は、溶接用コンデンサ5が放電した後、溶接トランス4の漏れインダクタンスや回路のインダクタンス分を有する合成のインダクタンスLと溶接用コンデンサ5のキャパシタCとからなる振動(共振)による充電電圧とは逆極性の電圧、すなわち、反転電圧ではオンしないようにする。この動作を実現するために、反転電圧を阻止する開閉機能を有する回路構成のものを用いる。具体的には、充電用の整流回路の正極側または負極側の整流素子にサイリスタを用い、充電終了後にゲート信号を与えないようにする。
After the welding capacitor 5 is discharged, the charging circuit 1 has a charging voltage due to vibration (resonance) composed of the combined inductance L having the leakage inductance of the welding transformer 4 and the inductance of the circuit and the capacitor C of the welding capacitor 5. Is not turned on with a reverse polarity voltage, that is, with an inverted voltage. In order to realize this operation, a circuit configuration having an opening / closing function for blocking an inversion voltage is used. Specifically, a thyristor is used for the positive or negative rectifier element of the charging rectifier circuit so that no gate signal is given after the end of charging.
溶接トランス4の1次巻線4aと溶接用コンデンサ5との直列回路は、充電回路1の直流出力端子2、3間に並列に接続される。溶接トランス4は、1ターン程度の2次巻線4bとこれに比べて巻数の大きな1次巻線4aとを有する。溶接トランス4の2次巻線4bの両端には、第1、第2の溶接電極7、8が接続される。第1、第2の溶接電極7、8は一般的なものでもよいので説明を省略する。溶接用コンデンサ5は、例えば、複数の有極性の電解コンデンサを並列に接続したブロックやこれらのブロックを複数個並列に接続したコンデンサバンク、又は無極性(両極性)の、例えばポリプロピレンフィルムコンデンサを複数個並列に接続したブロックやこれらのブロックを複数個並列に接続したコンデンサバンクなどである。
The series circuit of the primary winding 4 a of the welding transformer 4 and the welding capacitor 5 is connected in parallel between the DC output terminals 2 and 3 of the charging circuit 1. The welding transformer 4 has a secondary winding 4b of about one turn and a primary winding 4a having a larger number of turns than the secondary winding 4b. First and second welding electrodes 7 and 8 are connected to both ends of the secondary winding 4 b of the welding transformer 4. Since the first and second welding electrodes 7 and 8 may be general ones, description thereof is omitted. The welding capacitor 5 includes, for example, a block in which a plurality of polar electrolytic capacitors are connected in parallel, a capacitor bank in which a plurality of these blocks are connected in parallel, or a plurality of nonpolar (bipolar) polypropylene film capacitors, for example. Blocks connected in parallel or capacitor banks in which a plurality of these blocks are connected in parallel.
放電用スイッチ6は、溶接トランス4の1次巻線4aと溶接用コンデンサ5との直列回路に並列に接続される。放電用スイッチ6がオンすると、溶接用コンデンサ5からの放電回路が形成される。実施形態1では、放電用スイッチ6としてサイリスタを用いるので、実施形態1の以下の説明では、放電用スイッチ6を放電用サイリスタ6として説明する。また、放電用サイリスタ6は、アノード側が充電回路1の直流出力端子2に、カソード側が直流出力端子3にそれぞれ接続される。充電回路1がコンデンサ5を充電する期間では放電用サイリスタ6はオフ状態にする。
The discharge switch 6 is connected in parallel to the series circuit of the primary winding 4 a of the welding transformer 4 and the welding capacitor 5. When the discharge switch 6 is turned on, a discharge circuit from the welding capacitor 5 is formed. In the first embodiment, a thyristor is used as the discharge switch 6. Therefore, in the following description of the first embodiment, the discharge switch 6 will be described as the discharge thyristor 6. The discharge thyristor 6 has an anode connected to the DC output terminal 2 of the charging circuit 1 and a cathode connected to the DC output terminal 3. During the period in which the charging circuit 1 charges the capacitor 5, the discharging thyristor 6 is turned off.
コントローラ10は、絶縁駆動回路9を介して放電用スイッチ6に駆動信号を与える。絶縁駆動回路9は、例えば、ホトカプラを用いて、コントローラ10からのゲート信号を絶縁伝達し、図示しないゲートアンプでサイリスタのゲート信号を発生する。ホトカプラとゲートアンプは一般的なものでもよいので、詳細な説明を省略する。実施形態1では、コントローラ10は、絶縁駆動回路9を通して、図6(C)に示すような時刻t1から時刻t2の後まで連続する駆動信号を放電用サイリスタ6のゲート-カソード間に与える。
The controller 10 gives a drive signal to the discharge switch 6 through the insulation drive circuit 9. The insulation drive circuit 9 insulates and transmits the gate signal from the controller 10 using, for example, a photocoupler, and generates the gate signal of the thyristor with a gate amplifier (not shown). Since the photocoupler and the gate amplifier may be general ones, detailed description thereof is omitted. In the first embodiment, the controller 10 provides a continuous drive signal between the gate and cathode of the discharge thyristor 6 through the insulated drive circuit 9 from time t1 to time t2 as shown in FIG.
次に、実施形態1にかかるコンデンサ式溶接方法及び装置の動作を説明する。図2は、放電用サイリスタ6がオンして溶接用コンデンサ5の充電電荷を放電する状態を説明するための図である。図3は、溶接用コンデンサ5の充電電荷を放電して放電用サイリスタ6がオフした状態を説明するための図である。図4は、放電用サイリスタ6がオフした状態で第1の溶接電極7と第2の溶接電極8との間が開放された状態を説明するための図である。図5は、第1の溶接電極7と第2の溶接電極8との間が開放されるときに放電用サイリスタ6がオンする状態を説明するための図である。図6は、各部の電流波形と電圧波形、駆動信号波形を示す図である。
Next, the operation of the capacitor welding method and apparatus according to the first embodiment will be described. FIG. 2 is a diagram for explaining a state in which the discharging thyristor 6 is turned on and the charging charge of the welding capacitor 5 is discharged. FIG. 3 is a view for explaining a state in which the discharge thyristor 6 is turned off by discharging the charge of the welding capacitor 5. FIG. 4 is a view for explaining a state in which the space between the first welding electrode 7 and the second welding electrode 8 is opened in a state where the discharging thyristor 6 is turned off. FIG. 5 is a diagram for explaining a state in which the discharge thyristor 6 is turned on when the space between the first welding electrode 7 and the second welding electrode 8 is opened. FIG. 6 is a diagram showing a current waveform, a voltage waveform, and a drive signal waveform of each part.
図1において、充電回路1が充電動作を開始すると、直流電流が、直流出力端子2から溶接トランス4の1次巻線4a、溶接用コンデンサ5を通して直流出力端子3に流れる。溶接用コンデンサ5は、図2に示す極性で、所定の電圧(+V1)まで充電される。充電制御方法については、例えば、溶接用コンデンサ5が設定電圧になるまでは、溶接用コンデンサ5にほぼ一定の充電電流を流す定電流制御が行われる。
1, when the charging circuit 1 starts a charging operation, a direct current flows from the direct current output terminal 2 to the direct current output terminal 3 through the primary winding 4 a of the welding transformer 4 and the welding capacitor 5. The welding capacitor 5 is charged to a predetermined voltage (+ V1) with the polarity shown in FIG. As for the charge control method, for example, until the welding capacitor 5 reaches a set voltage, constant current control is performed so that a substantially constant charging current flows through the welding capacitor 5.
溶接用コンデンサ5が所定の電圧(+V1)まで充電されると、開閉機能を有する充電回路1は、直流出力端子2、3から電気的に遮断される。溶接用コンデンサ5の充電中は、放電用サイリスタ6がオフ状態にある。この後、コントローラ10から絶縁駆動回路9を通して、図6(C)に示すように、時刻t1で放電用サイリスタ6に駆動信号が与えられる。その駆動信号によって放電用サイリスタ6がターンオンする。図2に示すように、溶接トランス4の1次巻線4aには溶接用コンデンサ5の充電電荷による放電電流I1が流れる。放電電流I1は、主に溶接電流I2として溶接トランス4の2次巻線4bに流れ、一部は励磁電流I3として溶接トランス4の1次巻線4aに流れる。溶接トランス4の1次巻線4aと2次巻線4bの巻数比nとすると、放電電流I1=I2/n+I3となる。
When the welding capacitor 5 is charged to a predetermined voltage (+ V1), the charging circuit 1 having an opening / closing function is electrically disconnected from the DC output terminals 2 and 3. While the welding capacitor 5 is being charged, the discharging thyristor 6 is in an off state. Thereafter, as shown in FIG. 6C, a drive signal is given from the controller 10 to the discharging thyristor 6 through the insulated drive circuit 9 at time t1. The discharge thyristor 6 is turned on by the drive signal. As shown in FIG. 2, a discharge current I <b> 1 due to the charge of the welding capacitor 5 flows through the primary winding 4 a of the welding transformer 4. The discharge current I1 mainly flows as the welding current I2 to the secondary winding 4b of the welding transformer 4, and a part of the discharge current I1 flows as the exciting current I3 to the primary winding 4a of the welding transformer 4. When the turns ratio n of the primary winding 4a and the secondary winding 4b of the welding transformer 4 is assumed, the discharge current I1 = I2 / n + I3.
放電用サイリスタ6がターンオンすると、1次巻線4aと2次巻線4bとの巻数比に相応する大きい急峻な溶接電流I2が、第1の溶接電極7、被溶接物W1とW2、第2の溶接電極8を流れる。溶接電流I2が流れることで、被溶接物W1とW2との溶接が行われる。この実施形態1では、放電用サイリスタ6がターンオンすると、放電電流I1の電流波形は、図6(B)に示すように、正弦波状の波形となる。この正弦波状の波形は、溶接トランス4の漏れインダクタンスや回路のインダクタンス分からなる合成のインダクタンスLと溶接用コンデンサ5のキャパシタCとによる振動(共振)による。したがって、図6(B)に示す放電電流I1の電流波形のパルス幅は、実際上、数百ミリ秒以上とはならず、第1、第2の溶接電極7、8の機械的動作に要する時間に比べて短いので、本発明では放電電流I1の波尾の問題を考慮する必要は無い。
When the discharge thyristor 6 is turned on, a large and steep welding current I2 corresponding to the turns ratio of the primary winding 4a and the secondary winding 4b is applied to the first welding electrode 7, the workpieces W1 and W2, the second The welding electrode 8 flows. When the welding current I2 flows, the workpieces W1 and W2 are welded. In the first embodiment, when the discharge thyristor 6 is turned on, the current waveform of the discharge current I1 becomes a sinusoidal waveform as shown in FIG. 6B. This sinusoidal waveform is caused by vibration (resonance) caused by a combined inductance L composed of a leakage inductance of the welding transformer 4 and a circuit inductance and a capacitor C of the welding capacitor 5. Therefore, the pulse width of the current waveform of the discharge current I1 shown in FIG. 6 (B) does not actually exceed several hundred milliseconds, and is required for the mechanical operation of the first and second welding electrodes 7 and 8. Since it is shorter than the time, it is not necessary to consider the wave tail problem of the discharge current I1 in the present invention.
放電用サイリスタ6のオンによって、インダクタンスLとキャパシタCとの振動によりコンデンサ5の電圧が逆極性に反転する。放電用サイリスタ6を通して放電電流I1が実質的に流れない状態になると、すなわち、放電電流I1が放電用サイリスタ6の保持電流よりも小さくなると、放電用サイリスタ6は自然消弧でオフする。オフの時点では、溶接用コンデンサ5は上記充電電荷とは逆極性に充電されるので、溶接用コンデンサ5の電圧は図6(A)及び図3に示す逆極性の電圧(-V2)となる。開閉機能を有する充電回路1はオフしているので、この逆極性の電圧(-V2)は放電されずに保持される。この逆極性の電圧(-V2)は、充電電荷による所定の充電電圧(+V1)に比べて小さい値である。放電用サイリスタ6がオンして溶接用コンデンサ5の充電電荷を放電した後、放電用サイリスタ6がオフする。図2に示す1次巻線4aを流れていた1次側の励磁電流I3は、そのまま1次巻線4aを流れ続けることができなくなるために、2次巻線4bに転流して図3に示す2次側の励磁電流I4となる。この励磁電流I4は溶接電流I2の向きと逆方向に流れ、2次巻線4bの極性を示す黒点側から第1の溶接電極7、被溶接物W1、W2、第2の溶接電極8を通じて2次巻線4bの非黒点側に流れる。
When the discharge thyristor 6 is turned on, the voltage of the capacitor 5 is reversed to the reverse polarity due to the vibration of the inductance L and the capacitor C. When the discharge current I1 does not substantially flow through the discharge thyristor 6, that is, when the discharge current I1 becomes smaller than the holding current of the discharge thyristor 6, the discharge thyristor 6 is turned off by natural arc extinction. At the time of turning off, the welding capacitor 5 is charged with the opposite polarity to the charged charge, so the voltage of the welding capacitor 5 becomes the opposite polarity voltage (−V2) shown in FIG. 6 (A) and FIG. . Since the charging circuit 1 having the opening / closing function is off, the reverse polarity voltage (−V2) is held without being discharged. This reverse polarity voltage (−V2) is a smaller value than the predetermined charging voltage (+ V1) by the charge. After the discharging thyristor 6 is turned on to discharge the charging charge of the welding capacitor 5, the discharging thyristor 6 is turned off. The primary side excitation current I3 flowing through the primary winding 4a shown in FIG. 2 cannot continue to flow through the primary winding 4a as it is, and is commutated to the secondary winding 4b. The secondary side exciting current I4 shown in FIG. This exciting current I4 flows in the direction opposite to the direction of the welding current I2 and flows through the first welding electrode 7, the workpieces W1, W2 and the second welding electrode 8 from the black dot side indicating the polarity of the secondary winding 4b. It flows to the non-black spot side of the next winding 4b.
この状態では、被溶接物W1とW2とは既に溶接されて溶接物品となっている。溶接物品は溶接される前よりも抵抗値は小さく、かつ溶接トランス4の2次側の回路内の抵抗成分は小さくなるように製作されているので、励磁電流I4は短時間では消滅しない。溶接速度を向上させるためには、溶接周期を短くする。このため、励磁電流I4が消滅せずに未だ2次側回路を流れている期間に、第1の溶接電極7と第2の溶接電極8との間を離す方向に機械的動作をさせ、第1の溶接電極7と第2の溶接電極8との間を開放する。ここでは、第1の溶接電極7と第2の溶接電極8との間を開放するとは、第1の溶接電極7と第2の溶接電極8のいずれかが溶接物品(W1、W2)から離れ、電気的に非接続になることを言う。図6(C)の時刻t2で、第1の溶接電極7と第2の溶接電極8との間を開放するものとする。
In this state, the workpieces W1 and W2 are already welded and become welded articles. Since the welded article has a resistance value smaller than that before welding and the resistance component in the circuit on the secondary side of the welding transformer 4 is made smaller, the exciting current I4 does not disappear in a short time. In order to improve the welding speed, the welding cycle is shortened. For this reason, during the period in which the excitation current I4 has not disappeared and is still flowing through the secondary circuit, the first welding electrode 7 and the second welding electrode 8 are mechanically moved in a direction away from each other, The space between the first welding electrode 7 and the second welding electrode 8 is opened. Here, opening between the first welding electrode 7 and the second welding electrode 8 means that either the first welding electrode 7 or the second welding electrode 8 is separated from the welding article (W1, W2). Say, become electrically disconnected. It is assumed that the space between the first welding electrode 7 and the second welding electrode 8 is opened at time t2 in FIG.
図4に示すように、時刻t2で第1の溶接電極7と第2の溶接電極8との間を開放すると、図3に示される励磁電流I4は2次側回路を流れることができなくなる。このため、溶接トランス4の1次巻線4aと2次巻線4bとには図4の極性で理論的には無限大のサージ電圧(+Vs1、+Vs2)が発生する。ここでは、1次巻線4aに発生するサージ電圧Vs1は、溶接用コンデンサ5の充電電圧(+V1)と同じ極性である。したがって、サージ電圧Vs1が発生するときに放電用サイリスタ6がオンできる状態になければ、1次巻線4aに生じる大きなサージ電圧Vs1は放電用サイリスタ6のアノード-カソード間に印加される。この場合には、順方向阻止特性の大きなサイリスタを用いなければならない。なお、溶接トランス4の1次巻線4aに発生するサージ電圧Vs1は、2次巻線4bに発生するサージ電圧Vs2よりも1次巻線と2次巻線との巻数比n分大きくなる(Vs1=n×Vs2)。
As shown in FIG. 4, when the space between the first welding electrode 7 and the second welding electrode 8 is opened at time t2, the exciting current I4 shown in FIG. 3 cannot flow through the secondary circuit. Therefore, theoretically infinite surge voltages (+ Vs1, + Vs2) are generated in the primary winding 4a and the secondary winding 4b of the welding transformer 4 with the polarity shown in FIG. Here, the surge voltage Vs1 generated in the primary winding 4a has the same polarity as the charging voltage (+ V1) of the welding capacitor 5. Therefore, if the discharge thyristor 6 is not in a state where it can be turned on when the surge voltage Vs1 is generated, a large surge voltage Vs1 generated in the primary winding 4a is applied between the anode and the cathode of the discharge thyristor 6. In this case, a thyristor having a large forward blocking characteristic must be used. The surge voltage Vs1 generated in the primary winding 4a of the welding transformer 4 is larger than the surge voltage Vs2 generated in the secondary winding 4b by the turn ratio n between the primary winding and the secondary winding ( Vs1 = n × Vs2).
しかし、実施形態1にあっては、第1の溶接電極7と第2の溶接電極8との間を開放する時刻t2では、放電用サイリスタ6のゲートに駆動信号を印加する。このため、1次巻線4aに発生するサージ電圧(+Vs1)が溶接用コンデンサ5の逆極性の電圧(-V2)の絶対値を越えると同時に、放電用サイリスタ6は再度ターンオンする。放電用サイリスタ6を通して図6に示すサージ電流I5を溶接用コンデンサ5に流し、溶接用コンデンサ5を電圧(-V3)に充電する。つまり、1次巻線4aに発生するサージエネルギーは、放電用サイリスタ6を通して溶接用コンデンサ5で吸収される。なお、実施形態1では溶接用コンデンサ5の容量が大きいので、電圧(-V3)は電圧(-V2)とほとんど同じである。
However, in the first embodiment, a drive signal is applied to the gate of the discharge thyristor 6 at time t2 when the gap between the first welding electrode 7 and the second welding electrode 8 is opened. Therefore, at the same time as the surge voltage (+ Vs1) generated in the primary winding 4a exceeds the absolute value of the reverse polarity voltage (−V2) of the welding capacitor 5, the discharging thyristor 6 is turned on again. A surge current I5 shown in FIG. 6 is supplied to the welding capacitor 5 through the discharge thyristor 6, and the welding capacitor 5 is charged to a voltage (−V3). That is, the surge energy generated in the primary winding 4 a is absorbed by the welding capacitor 5 through the discharge thyristor 6. In the first embodiment, since the capacity of the welding capacitor 5 is large, the voltage (−V3) is almost the same as the voltage (−V2).
したがって、この実施形態1にあっては、溶接トランス4の励磁電流I4が第1、第2の溶接電極7、8及び溶接物品を流れているときに第1の溶接電極7と第2の溶接電極8との間を開放しても、放電用サイリスタ6に大きな値のサージ電圧(+Vs1)は発生しない。溶接用コンデンサ5の電圧を-V2とすると、放電用サイリスタ6の電圧は、溶接用コンデンサ5の電圧(-V2)に制限される。このため、放電用サイリスタ6は、高いサージ電圧Vs1までの耐圧を必要としない。溶接トランス4の巻数比をnとする。励磁電流I4が流れている状態で第1の溶接電極7と第2の溶接電極8との間を開放する。放電用サイリスタ6のオンにより、第1の溶接電極7と第2の溶接電極8との間に発生するサージ電圧はV2/nに低下する。この場合、アフターフラッシュは生じ難い。したがって、実施形態1によれば、励磁電流I4が溶接電極間を流れている状態で溶接電極間を開放する場合に、特別な回路部品を付加する必要がない。また、放電用サイリスタ6の耐圧を増大させること無く、サージ電圧を十分に小さな値に抑制できるので、アフターフラッシュを防止することができる。なお、溶接用コンデンサ5の電圧(-V2)や電圧(-V3)の値は、回路の損失などによって、充電電圧(+V1)値よりも当然小さい値になる。
Therefore, in the first embodiment, the first welding electrode 7 and the second welding are performed when the exciting current I4 of the welding transformer 4 flows through the first and second welding electrodes 7 and 8 and the welding article. Even if the electrode 8 is opened, a large surge voltage (+ Vs1) is not generated in the discharge thyristor 6. Assuming that the voltage of the welding capacitor 5 is −V2, the voltage of the discharging thyristor 6 is limited to the voltage (−V2) of the welding capacitor 5. For this reason, the discharge thyristor 6 does not require a withstand voltage up to the high surge voltage Vs1. Let the winding ratio of the welding transformer 4 be n. A space between the first welding electrode 7 and the second welding electrode 8 is opened in a state where the exciting current I4 is flowing. When the discharge thyristor 6 is turned on, the surge voltage generated between the first welding electrode 7 and the second welding electrode 8 is reduced to V2 / n. In this case, after-flash is unlikely to occur. Therefore, according to the first embodiment, there is no need to add a special circuit component when the gap between the welding electrodes is opened while the exciting current I4 is flowing between the welding electrodes. Further, since the surge voltage can be suppressed to a sufficiently small value without increasing the withstand voltage of the discharge thyristor 6, afterflash can be prevented. Note that the values of the voltage (−V2) and the voltage (−V3) of the welding capacitor 5 are naturally smaller than the value of the charging voltage (+ V1) due to circuit loss and the like.
[実施形態2]
次に、図7及び図8を用いて、本発明の実施形態2に係る溶接方法及びコンデンサ式溶接装置を説明する。実施形態2では、直流出力端子2、3間に並列に溶接用コンデンサ5が接続される。溶接トランス4の1次巻線4aと放電用スイッチ6との直列回路は、溶接用コンデンサ5に対して並列に接続される。充電回路1は、溶接用コンデンサ5の直流出力端子2側が正、直流出力端子3側が負となる極性で溶接用コンデンサ5を充電する。充電回路1から溶接用コンデンサ5に供給される充電電流は、溶接トランス4の1次巻線4aを流れない。充電回路1が溶接用コンデンサ5を充電する期間は、放電用スイッチ6をオフ状態にする。また、実施形態2では、放電用サイリスタ6と並列に逆極性で接続されたエネルギー回収用スイッチ11を用いる。ここでは、放電用スイッチ6として逆方向阻止特性を有するサイリスタを用い、エネルギー回収用スイッチ11としてサイリスタを用いる。実施形態2の以下の説明では、放電用スイッチ6を放電用サイリスタ6、エネルギー回収用スイッチ11をエネルギー回収用サイリスタ11として説明する。第1の溶接電極7と第2の溶接電極8は、図1と同様に溶接トランス4の2次巻線に並列に接続される。第1の溶接電極7と第2の溶接電極8とで挟んだ被溶接物W1、W2に溶接電流を流して溶接を行う。 [Embodiment 2]
Next, a welding method and a capacitor welding apparatus according toEmbodiment 2 of the present invention will be described with reference to FIGS. 7 and 8. In the second embodiment, a welding capacitor 5 is connected in parallel between the DC output terminals 2 and 3. A series circuit of the primary winding 4 a of the welding transformer 4 and the discharge switch 6 is connected in parallel to the welding capacitor 5. The charging circuit 1 charges the welding capacitor 5 with a polarity such that the DC output terminal 2 side of the welding capacitor 5 is positive and the DC output terminal 3 side is negative. The charging current supplied from the charging circuit 1 to the welding capacitor 5 does not flow through the primary winding 4 a of the welding transformer 4. During the period in which the charging circuit 1 charges the welding capacitor 5, the discharging switch 6 is turned off. In the second embodiment, the energy recovery switch 11 connected in parallel with the discharge thyristor 6 in reverse polarity is used. Here, a thyristor having reverse blocking characteristics is used as the discharge switch 6, and a thyristor is used as the energy recovery switch 11. In the following description of the second embodiment, the discharge switch 6 is described as the discharge thyristor 6 and the energy recovery switch 11 is described as the energy recovery thyristor 11. The first welding electrode 7 and the second welding electrode 8 are connected in parallel to the secondary winding of the welding transformer 4 as in FIG. Welding is performed by passing a welding current through the workpieces W1 and W2 sandwiched between the first welding electrode 7 and the second welding electrode 8.
次に、図7及び図8を用いて、本発明の実施形態2に係る溶接方法及びコンデンサ式溶接装置を説明する。実施形態2では、直流出力端子2、3間に並列に溶接用コンデンサ5が接続される。溶接トランス4の1次巻線4aと放電用スイッチ6との直列回路は、溶接用コンデンサ5に対して並列に接続される。充電回路1は、溶接用コンデンサ5の直流出力端子2側が正、直流出力端子3側が負となる極性で溶接用コンデンサ5を充電する。充電回路1から溶接用コンデンサ5に供給される充電電流は、溶接トランス4の1次巻線4aを流れない。充電回路1が溶接用コンデンサ5を充電する期間は、放電用スイッチ6をオフ状態にする。また、実施形態2では、放電用サイリスタ6と並列に逆極性で接続されたエネルギー回収用スイッチ11を用いる。ここでは、放電用スイッチ6として逆方向阻止特性を有するサイリスタを用い、エネルギー回収用スイッチ11としてサイリスタを用いる。実施形態2の以下の説明では、放電用スイッチ6を放電用サイリスタ6、エネルギー回収用スイッチ11をエネルギー回収用サイリスタ11として説明する。第1の溶接電極7と第2の溶接電極8は、図1と同様に溶接トランス4の2次巻線に並列に接続される。第1の溶接電極7と第2の溶接電極8とで挟んだ被溶接物W1、W2に溶接電流を流して溶接を行う。 [Embodiment 2]
Next, a welding method and a capacitor welding apparatus according to
コントローラ10は、絶縁駆動回路9を通して図8(C)に示すような2つの駆動信号Sa、Sbを放電用サイリスタ6に与える。時刻t2の後の時刻t3には破線で示す駆動信号Ssをエネルギー回収用サイリスタ11に与える。充電回路1によって溶接用コンデンサ5が設定電圧V1まで充電された後、時刻t1で放電用サイリスタ6がオンする。コントローラ10は、絶縁駆動回路9を通して、図8(C)に示すように、時刻t1に駆動信号Saを放電用サイリスタ6のゲート-カソード間に印加する。
The controller 10 gives two driving signals Sa and Sb as shown in FIG. 8C to the discharging thyristor 6 through the insulating driving circuit 9. At time t3 after time t2, a drive signal Ss indicated by a broken line is given to the energy recovery thyristor 11. After charging capacitor 5 is charged to set voltage V1 by charging circuit 1, discharging thyristor 6 is turned on at time t1. As shown in FIG. 8C, the controller 10 applies the drive signal Sa between the gate and the cathode of the discharge thyristor 6 through the insulated drive circuit 9 at time t1.
これに伴い、放電用サイリスタ6はターンオンして、溶接用コンデンサ5の充電電荷を放電し、溶接トランス4の1次巻線4aを通して図8(B)に示すような放電電流I1を流す。実施形態1と同様に、放電電流I1の電流波形は、溶接トランス4のインダクタンスや回路のインダクタンス分を有するインダクタンスLと溶接用コンデンサ5のキャパシタCとからなる振動(共振)による正弦波状の波形となる。実施形態1と同様に、1次巻線4aには放電電流と励磁電流が流れる。溶接電流は、2次巻線4bの黒点側から第1の溶接電極7、被溶接物W1とW2、第2の溶接電極8を通して2次巻線4bの非黒点側に流れて溶接が行われる。
Accordingly, the discharge thyristor 6 is turned on to discharge the charging charge of the welding capacitor 5, and a discharge current I 1 as shown in FIG. 8B flows through the primary winding 4 a of the welding transformer 4. Similarly to the first embodiment, the current waveform of the discharge current I1 is a sinusoidal waveform caused by vibration (resonance) including the inductance L of the inductance of the welding transformer 4 and the inductance of the circuit and the capacitor C of the welding capacitor 5. Become. As in the first embodiment, a discharge current and an excitation current flow through the primary winding 4a. The welding current flows from the black spot side of the secondary winding 4b to the non-black spot side of the secondary winding 4b through the first welding electrode 7, the workpieces W1 and W2, and the second welding electrode 8 to perform welding. .
また、放電用サイリスタ6のオンによって、インダクタンスLとキャパシタCとの振動が生じると、放電用サイリスタ6のオフの時点では、溶接用コンデンサ5は充電電荷とは逆極性の電圧(-V2)に充電される。この逆極性の電圧は充電電荷による充電電圧(+V1)に比べて小さい値である。次に放電用サイリスタ6がオフすると、実施形態1と同様に、1次巻線4aを流れていた励磁電流は2次巻線4bに転流する。励磁電流は、2次巻線4bの非黒点側から第2の溶接電極8、被溶接物W2とW1、第1の溶接電極7を通して2次巻線4bの黒点側に流れる。この励磁電流は短時間では消滅せずに2次側回路を流れる。
Further, when the discharge thyristor 6 is turned on and the inductance L and the capacitor C are vibrated, the welding capacitor 5 has a voltage (−V2) having a polarity opposite to that of the charge when the discharge thyristor 6 is turned off. Charged. This reverse polarity voltage is a smaller value than the charge voltage (+ V1) by the charge. Next, when the discharging thyristor 6 is turned off, the excitation current flowing in the primary winding 4a is commutated to the secondary winding 4b as in the first embodiment. The exciting current flows from the non-black spot side of the secondary winding 4b to the black spot side of the secondary winding 4b through the second welding electrode 8, workpieces W2 and W1, and the first welding electrode 7. This excitation current flows through the secondary circuit without disappearing in a short time.
時刻t2の直前に、コントローラ10から絶縁駆動回路9を通して駆動信号Sbが放電用サイリスタ6のゲート-カソード間に印加される。このため、放電用サイリスタ6はカソード側の電圧に比べてアノード側の電圧が大きくなるといつでもターンオンできる状態となる。時刻t2で、第1、第2の溶接電極7と8の少なくとも一方が動いて、第1の溶接電極7又は第2の溶接電極8が被溶接物W1又はW2から離れて電気的に非接続状態になる。時刻t2の直前まで第1、第2の溶接電極7、8を通じて流れていた励磁電流は、時刻t2後に2次側回路を流れることができなくなるから、1次巻線4aにサージ電圧が発生する。このサージ電圧は溶接用コンデンサ5を介して放電用サイリスタ6のアノードに印加される。サージ電圧が溶接用コンデンサ5の電圧(-V2)の値を越えると、放電用サイリスタ6はターンオンして、1次巻線4aに発生したサージ電圧をサージ電流I5として溶接用コンデンサ5で吸収させる。このため、上記電圧(-V2)を実質上越えるサージ電圧が放電用サイリスタ6のアノードーカソード間に印加されることがない。よって、溶接電極間の開放時にアフターフラッシュの発生を防止することができる。
Immediately before time t2, the drive signal Sb is applied between the gate and cathode of the discharge thyristor 6 through the insulated drive circuit 9 from the controller 10. Therefore, the discharge thyristor 6 can be turned on at any time when the voltage on the anode side becomes larger than the voltage on the cathode side. At time t2, at least one of the first and second welding electrodes 7 and 8 moves, and the first welding electrode 7 or the second welding electrode 8 moves away from the workpiece W1 or W2 and is not electrically connected. It becomes a state. Since the excitation current that has been flowing through the first and second welding electrodes 7 and 8 until immediately before time t2 can no longer flow through the secondary circuit after time t2, a surge voltage is generated in the primary winding 4a. . This surge voltage is applied to the anode of the discharge thyristor 6 through the welding capacitor 5. When the surge voltage exceeds the value of the voltage (−V2) of the welding capacitor 5, the discharging thyristor 6 is turned on and the surge voltage generated in the primary winding 4a is absorbed by the welding capacitor 5 as the surge current I5. . Therefore, a surge voltage substantially exceeding the voltage (−V2) is not applied between the anode and cathode of the discharge thyristor 6. Therefore, it is possible to prevent the occurrence of after flash when the welding electrodes are opened.
時刻t2で放電用サイリスタ6がオンし、サージエネルギーを溶接用コンデンサ5に吸収した後に放電用サイリスタ6がオフする。時刻t3で、コントローラ10は絶縁駆動回路9を通してエネルギー回収用サイリスタ11に駆動信号Ssを与えてターンオンさせる。前述したように、このとき溶接用コンデンサ5は直流出力端子3が直流出力端子2に対して正極である電圧に充電されている。このため、その電荷はエネルギー回収用サイリスタ11を通して回路インダクタンスと振動し、直流出力端子2が直流出力端子3に対して正の極性で溶接用コンデンサ5を充電する。この充電は充電回路1によって充電される充電電荷の極性(正極性)と同じであり、サージエネルギーも重畳されているので、その分だけ次の充電時間をより短縮でき、かつ節電もできる。また、その電圧分だけ次の充電開始時に突入電流が流れ難くなるので、充電回路1の負担を軽減できる。
At time t2, the discharge thyristor 6 is turned on, and after the surge energy is absorbed by the welding capacitor 5, the discharge thyristor 6 is turned off. At time t3, the controller 10 supplies the drive signal Ss to the energy recovery thyristor 11 through the insulated drive circuit 9 to turn it on. As described above, the welding capacitor 5 is charged to a voltage at which the DC output terminal 3 is positive with respect to the DC output terminal 2 at this time. Therefore, the electric charge vibrates with the circuit inductance through the energy recovery thyristor 11, and the DC output terminal 2 charges the welding capacitor 5 with a positive polarity with respect to the DC output terminal 3. This charging is the same as the polarity (positive polarity) of the charging charge charged by the charging circuit 1 and the surge energy is also superimposed, so that the next charging time can be further shortened and power saving can be achieved. Further, since the inrush current is less likely to flow at the start of the next charging by the voltage, the burden on the charging circuit 1 can be reduced.
特に、被溶接物W1とW2が銅又はアルミニウムなどのように抵抗率の小さい高導電性の金属材料からなるときは、急峻に増大するパルス状の溶接電流を用いると共に、被溶接物W1とW2に対する加圧力の応答性を高速とする溶接方法を用いることが有効となる。このため、溶接用コンデンサ5に逆極性で充電される電圧(-V2)のエネルギーは大きくなる傾向がある。この場合には、溶接用コンデンサ5として有極性の電解コンデンサを用いる場合よりも、ポリプロピレンフィルムなどを誘電体として用いる無極性のフィルムコンデンサを用いた方が好ましい。このようにすることによって、溶接用コンデンサ5に何らのダメージを与えることなく、大きなエネルギーをより安全に回収することができる。
In particular, when the workpieces W1 and W2 are made of a highly conductive metal material having a low resistivity such as copper or aluminum, a rapidly increasing pulse-shaped welding current is used, and the workpieces W1 and W2 are used. It is effective to use a welding method in which the responsiveness of the applied pressure to is high. For this reason, the energy of the voltage (−V2) charged to the welding capacitor 5 with the reverse polarity tends to increase. In this case, it is preferable to use a nonpolar film capacitor using a polypropylene film or the like as a dielectric rather than using a polar electrolytic capacitor as the welding capacitor 5. By doing in this way, big energy can be collect | recovered more safely, without giving any damage to the capacitor | condenser 5 for welding.
前述した実施形態1では、放電用サイリスタ6に与えられる駆動信号は、図6(C)に示される。放電用サイリスタ6の駆動信号は、溶接用コンデンサ5に充電された充電電荷を放電する時刻t1のときに与えられ、その後、第1の溶接電極7と第2の溶接電極8との間を開放する時刻t2のときまで少なくとも与えられる。つまり放電用サイリスタ6には、連続する駆動信号が与えられている。また、実施形態2では、放電用サイリスタ6に与えられる駆動信号は、図8(C)に示される。溶接用コンデンサ5に充電された充電電荷を放電する時刻t1のときに駆動信号Saが与えられた後、駆動信号は放電用サイリスタ6に与えられなくなる。そして、第1の溶接電極7と第2の溶接電極8との間を開放する時刻t2の直前には少なくとも放電用サイリスタ6に駆動信号Sbが与えられる。つまり放電用サイリスタ6には、途中で遮断される駆動信号が与えられている。これらの実施形態は一例であって、これに限定されるものではない。例えば、実施形態1において、実施形態2と同様の駆動信号が放電用サイリスタ6に与えられてもよく、実施形態2において、実施形態1と同様の駆動信号が放電用サイリスタ6に与えられてもよい。
In the first embodiment described above, the drive signal applied to the discharge thyristor 6 is shown in FIG. The driving signal for the discharging thyristor 6 is given at time t1 when the charging charge charged in the welding capacitor 5 is discharged, and thereafter, the first welding electrode 7 and the second welding electrode 8 are opened. It is given at least until time t2. That is, a continuous drive signal is given to the discharge thyristor 6. In the second embodiment, the drive signal applied to the discharge thyristor 6 is shown in FIG. After the drive signal Sa is given at the time t1 when the charge charged in the welding capacitor 5 is discharged, the drive signal is no longer given to the discharge thyristor 6. The drive signal Sb is applied to at least the discharge thyristor 6 immediately before time t2 when the gap between the first welding electrode 7 and the second welding electrode 8 is opened. That is, the discharge thyristor 6 is given a drive signal that is interrupted halfway. These embodiments are merely examples, and the present invention is not limited to these. For example, in the first embodiment, a driving signal similar to that in the second embodiment may be applied to the discharging thyristor 6, and in the second embodiment, a driving signal similar to that in the first embodiment may be applied to the discharging thyristor 6. Good.
前述した実施形態1のコンデンサ式溶接装置における放電用スイッチ6と逆極性にして並列にエネルギー回収用サイリスタ11を接続しても、前述と同様な効果を得ることができる。前述した実施形態1、2の放電用スイッチ6、エネルギー回収用サイリスタ11としては、サイリスタの他に逆方向阻止特性を有するバイポーラトランジスタ、あるいはIGBTやMOSFETなどの半導体スイッチを用いてもよい。また、放電用スイッチ6として双方向のオンオフ機能を有する双方向半導体スイッチを用い、この双方向半導体スイッチに放電用スイッチ6とエネルギー回収用サイリスタ11の両者の働きをさせてもよい。前述の実施形態1、2では絶縁駆動回路9をホトカプラとして説明したが、これに限定されず、例えば、絶縁トランスなどを用いてもよい。
Even if the thyristor 11 for energy recovery is connected in parallel with the polarity opposite to that of the discharge switch 6 in the capacitor type welding apparatus of the first embodiment described above, the same effect as described above can be obtained. As the discharge switch 6 and the energy recovery thyristor 11 according to the first and second embodiments described above, a bipolar transistor having reverse blocking characteristics, or a semiconductor switch such as IGBT or MOSFET may be used in addition to the thyristor. Alternatively, a bidirectional semiconductor switch having a bidirectional on / off function may be used as the discharge switch 6, and the bidirectional semiconductor switch may function as both the discharge switch 6 and the energy recovery thyristor 11. In the first and second embodiments, the insulating drive circuit 9 has been described as a photocoupler. However, the present invention is not limited to this. For example, an insulating transformer may be used.
図示しないが、上述の実施形態1、2等において、抵抗手段とダイオードとを直列接続した回路を溶接用コンデンサ5に並列に接続してもよい。この抵抗手段とダイオードとの直列回路を通して溶接用コンデンサ5の上記逆極性の電圧(-V2)を呈する逆極性電荷を放電させることができる。つまり、抵抗手段とダイオードとの直列回路によって逆極性のエネルギーを消費させるので、逆極性の電圧(-V2)を下げることができる。例えば、この逆極性の電圧(-V2)をほぼゼロボルトにすることができる。この結果、第1の溶接電極7と第2の溶接電極8との間を開放するときに、溶接トランス4の励磁電流に起因して生じるサージ電圧を例えばほぼゼロボルトまで抑制でき、アフターフラッシュをより確実に防止することができる。なお、上述の抵抗手段とダイオードとの直列回路において、ダイオードに替えてサイリスタや半導体スイッチを用いることもできる。
Although not shown, a circuit in which the resistance means and the diode are connected in series may be connected in parallel to the welding capacitor 5 in the first and second embodiments. Through the series circuit of the resistance means and the diode, the reverse polarity charge exhibiting the reverse polarity voltage (-V2) of the welding capacitor 5 can be discharged. That is, since the reverse polarity energy is consumed by the series circuit of the resistance means and the diode, the reverse polarity voltage (−V2) can be lowered. For example, the reverse polarity voltage (−V2) can be set to approximately zero volts. As a result, when the gap between the first welding electrode 7 and the second welding electrode 8 is opened, the surge voltage caused by the exciting current of the welding transformer 4 can be suppressed to, for example, almost zero volts, and the afterflash can be further reduced. It can be surely prevented. In the series circuit of the resistance means and the diode described above, a thyristor or a semiconductor switch can be used instead of the diode.
さらに、上述した実施形態1の放電用スイッチ6を第1の放電用サイリスタとし、この第1の放電用サイリスタと逆並列に第2の放電用サイリスタを接続してもよい。これにより、第1の放電用サイリスタと第2の放電用サイリスタとを用いて溶接用コンデンサ5に蓄積される電荷を放電することができる。前述した実施形態1と同様に、第1の放電用サイリスタ6をオンさせる。溶接用コンデンサ5の正極性の電圧、すなわち図2に示される溶接用コンデンサ5の電圧(+V1)によって正極性の電荷を放電させる。この正極性の電荷による放電が終わると、次に、第2の放電用サイリスタをオンさせる。正極性の電荷の放電によって溶接用コンデンサ5に充電される逆極性の電圧、すなわち図3に示される溶接用コンデンサ5の極性の電圧(-V2)を呈する電荷を放電させる。この溶接用コンデンサ5の極性の電圧(-V2)の放電によって、溶接用コンデンサ5は再び正極性の電圧、すなわち図2の電圧(+V1)と同じ極性の電圧で、V1、V2よりも絶対値が低い電圧に充電される。
Furthermore, the discharge switch 6 of the first embodiment described above may be used as the first discharge thyristor, and the second discharge thyristor may be connected in reverse parallel to the first discharge thyristor. Thereby, the electric charge accumulated in the welding capacitor 5 can be discharged using the first discharge thyristor and the second discharge thyristor. As in the first embodiment, the first discharging thyristor 6 is turned on. The positive charge is discharged by the positive voltage of the welding capacitor 5, that is, the voltage (+ V1) of the welding capacitor 5 shown in FIG. When the discharge due to the positive charge is completed, the second discharge thyristor is then turned on. The reverse polarity voltage charged in the welding capacitor 5 by the discharge of the positive charge, that is, the charge having the polarity voltage (−V2) of the welding capacitor 5 shown in FIG. 3 is discharged. Due to the discharge of the polarity voltage (−V2) of the welding capacitor 5, the welding capacitor 5 is again a positive voltage, that is, a voltage having the same polarity as the voltage (+ V1) in FIG. Is charged to a low voltage.
第1の放電用サイリスタを通じて流れていた溶接用コンデンサの放電電流が、第1の放電用サイリスタが自然消弧により実質的に流れない状態になったときに、第2の放電用サイリスタはオンしないものとする。この場合は、実施形態1と同様に、図2のI3の方向で流れていた溶接トランス4の1次巻線の励磁電流は、図3のI4の向きで2次巻線の励磁電流として転流する。このI4の向きで2次巻線の励磁電流が流れている状態で第1の溶接電極7と第2の溶接電極8との間を開放するときに発生するサージ電圧は、図4に示したVs1、Vs2と同様の極性となる。よって、実施形態1と同様に、第1の放電用サイリスタをオンさせて、溶接トランス4の励磁電流に起因するサージ電圧を溶接用コンデンサ5によって吸収することができる。なお、この場合は、放電スイッチとして用いられる第2の放電用サイリスタの替わりに半導体スイッチを用いてもよい。
The second discharge thyristor is not turned on when the discharge current of the welding capacitor flowing through the first discharge thyristor becomes substantially non-flowing due to natural arc extinction. Shall. In this case, as in the first embodiment, the excitation current of the primary winding of the welding transformer 4 flowing in the direction of I3 in FIG. 2 is converted as the excitation current of the secondary winding in the direction of I4 in FIG. Shed. The surge voltage generated when the space between the first welding electrode 7 and the second welding electrode 8 is opened in the state where the exciting current of the secondary winding flows in the direction of I4 is shown in FIG. It has the same polarity as Vs1 and Vs2. Therefore, similarly to the first embodiment, the first discharge thyristor can be turned on, and the surge voltage caused by the exciting current of the welding transformer 4 can be absorbed by the welding capacitor 5. In this case, a semiconductor switch may be used instead of the second discharge thyristor used as the discharge switch.
一方、第1の放電用サイリスタがオフした後、第2の放電用サイリスタを通じて流れていた溶接用コンデンサの放電電流が第2の放電用サイリスタが自然消弧により実質的に流れない状態になったとき、第1の放電用サイリスタは再度オンしないものとする。この場合は、実施形態1とは異なり、図2のI3と逆方向に流れていた溶接トランスの1次巻線の励磁電流は、図3のI4と逆向きで2次巻線の励磁電流として転流する。このため、2次巻線の励磁電流が図3のI4と逆向きの流れている状態で第1の溶接電極7と第2の溶接電極8との間を開放するときに発生するサージ電圧は、図4に示したVs1、Vs2とは逆の極性、つまり、溶接トランスの1次巻線及び2次巻線の黒点がマイナスの極性となる。よって、第2の放電用サイリスタをオン状態にさせて、1次巻線に生じるサージ電圧を第2の放電用サイリスタを通して溶接用コンデンサ5にサージ電流として流すことにより、溶接トランス4の励磁電流に起因するサージ電圧を溶接用コンデンサ5によって吸収することができる。なお、この場合は、放電スイッチとして用いられる第2の放電用サイリスタの替わりにダイオードや半導体スイッチを用いてもよい。
On the other hand, after the first discharge thyristor is turned off, the discharge current of the welding capacitor flowing through the second discharge thyristor is in a state in which the second discharge thyristor does not substantially flow due to natural arc extinction. At this time, the first discharging thyristor is not turned on again. In this case, unlike the first embodiment, the exciting current of the primary winding of the welding transformer, which was flowing in the direction opposite to I3 in FIG. 2, is opposite to that of I4 in FIG. 3 as the exciting current of the secondary winding. Commutation. For this reason, the surge voltage generated when the space between the first welding electrode 7 and the second welding electrode 8 is opened while the excitation current of the secondary winding flows in the direction opposite to I4 in FIG. The opposite polarity to Vs1 and Vs2 shown in FIG. 4, that is, the black spots of the primary and secondary windings of the welding transformer have a negative polarity. Therefore, the second discharge thyristor is turned on, and the surge voltage generated in the primary winding is caused to flow as a surge current to the welding capacitor 5 through the second discharge thyristor. The resulting surge voltage can be absorbed by the welding capacitor 5. In this case, a diode or a semiconductor switch may be used instead of the second discharge thyristor used as the discharge switch.
よって、第1の放電用サイリスタと逆並列に第2の放電用サイリスタを接続した場合も、励磁電流に起因して生じるサージ電圧の極性に応じた第1又は第2の放電用サイリスタをオンさせる。このことによって、励磁電流が流れている溶接電極間を開放するときにアフターフラッシュが発生するのを防止でき、1次巻線に大きなサージ電圧が発生するのを防止することができるという本発明の効果を奏する。なお、実施形態2の回路構成で、図7に示す放電用スイッチ6に逆並列に接続されるエネルギー回収用サイリスタ11を上述の第2の放電用サイリスタとして作用させることもできる。この場合は、エネルギー回収用サイリスタ11も放電用スイッチに含まれるものとする。
Therefore, even when the second discharge thyristor is connected in antiparallel with the first discharge thyristor, the first or second discharge thyristor corresponding to the polarity of the surge voltage generated due to the excitation current is turned on. . As a result, it is possible to prevent the occurrence of afterflash when opening between the welding electrodes through which the excitation current flows, and to prevent a large surge voltage from being generated in the primary winding. There is an effect. In the circuit configuration of the second embodiment, the energy recovery thyristor 11 connected in antiparallel to the discharge switch 6 shown in FIG. 7 can also be used as the above-described second discharge thyristor. In this case, the energy recovery thyristor 11 is also included in the discharge switch.
1・・・充電回路
2、3・・・充電回路の直流出力端子
4・・・溶接トランス
4a・・・溶接トランス4の1次巻線
4b・・・溶接トランス4の2次巻線
5・・・溶接用コンデンサ
6・・・放電用スイッチ(放電用サイリスタ)
7・・・第1の溶接電極
8・・・第2の溶接電極
9・・・絶縁駆動回路
10・・・コントローラ
11・・・エネルギー回収用スイッチ11(エネルギー回収用サイリスタ)
W1、W2・・・被溶接物
L・・・合成のインダクタンス
C・・・溶接用コンデンサ5のキャパシタンス
V1・・・溶接用コンデンサ5の設定充電電圧
V2・・・溶接用コンデンサ5の逆極性の電圧
V3・・・放電用スイッチ6が2度目にオンした後の溶接用コンデンサ5の逆極性の電圧
Vs1・・・溶接トランス4の1次巻線4aに生じるサージ電圧
Vs2・・・溶接トランス4の2次巻線4bに生じるサージ電圧
I1・・・溶接用コンデンサ5の放電電流
I2・・・溶接電流
I3・・・溶接トランス4の1次巻線4aを流れる励磁電流
I4・・・溶接トランス4の2次巻線4bを流れる励磁電流
I5・・・1次巻線4aに生じるサージ電圧Vs1によるサージ電流
Sa、Sb・・・放電用スイッチ6の駆動信号
Ss・・・エネルギー回収用スイッチ11の駆動信号 DESCRIPTION OFSYMBOLS 1 ... Charging circuit 2, 3 ... DC output terminal of charging circuit 4 ... Welding transformer 4a ... Primary winding of welding transformer 4 4b ... Secondary winding of welding transformer 4 ..Capacitors for welding 6 ... Discharge switch (discharge thyristor)
DESCRIPTION OFSYMBOLS 7 ... 1st welding electrode 8 ... 2nd welding electrode 9 ... Insulation drive circuit 10 ... Controller 11 ... Switch 11 for energy recovery (Thyristor for energy recovery)
W1, W2: Workpiece L: Synthetic inductance C: Capacitance ofwelding capacitor 5 V1: Setting charging voltage of welding capacitor 5 V2: Reverse polarity of welding capacitor 5 Voltage V3... Reverse polarity voltage of welding capacitor 5 after discharge switch 6 is turned on for the second time Vs1... Surge voltage generated in primary winding 4a of welding transformer 4 Vs2. Surge voltage generated in secondary winding 4b of I1 ... Discharging current of welding capacitor 5 I2 ... Welding current I3 ... Excitation current flowing in primary winding 4a of welding transformer 4 I4 ... Welding transformer Excitation current flowing through the secondary winding 4b 4 I5 ... Surge current due to the surge voltage Vs1 generated in the primary winding 4a Sa, Sb ... Drive signal for the discharge switch 6 Ss ... Energy Guy drive signal of the recovery switch 11
2、3・・・充電回路の直流出力端子
4・・・溶接トランス
4a・・・溶接トランス4の1次巻線
4b・・・溶接トランス4の2次巻線
5・・・溶接用コンデンサ
6・・・放電用スイッチ(放電用サイリスタ)
7・・・第1の溶接電極
8・・・第2の溶接電極
9・・・絶縁駆動回路
10・・・コントローラ
11・・・エネルギー回収用スイッチ11(エネルギー回収用サイリスタ)
W1、W2・・・被溶接物
L・・・合成のインダクタンス
C・・・溶接用コンデンサ5のキャパシタンス
V1・・・溶接用コンデンサ5の設定充電電圧
V2・・・溶接用コンデンサ5の逆極性の電圧
V3・・・放電用スイッチ6が2度目にオンした後の溶接用コンデンサ5の逆極性の電圧
Vs1・・・溶接トランス4の1次巻線4aに生じるサージ電圧
Vs2・・・溶接トランス4の2次巻線4bに生じるサージ電圧
I1・・・溶接用コンデンサ5の放電電流
I2・・・溶接電流
I3・・・溶接トランス4の1次巻線4aを流れる励磁電流
I4・・・溶接トランス4の2次巻線4bを流れる励磁電流
I5・・・1次巻線4aに生じるサージ電圧Vs1によるサージ電流
Sa、Sb・・・放電用スイッチ6の駆動信号
Ss・・・エネルギー回収用スイッチ11の駆動信号 DESCRIPTION OF
DESCRIPTION OF
W1, W2: Workpiece L: Synthetic inductance C: Capacitance of
Claims (6)
- 充電回路から給電される電力によって溶接用コンデンサを充電し、放電用スイッチをオンして前記溶接用コンデンサに充電された充電電荷を溶接トランスの1次巻線に放電し、前記溶接トランスの2次巻線及び該2次巻線に接続された第1の溶接電極と第2の溶接電極とを通して溶接電流を被溶接物に通電して該被溶接物を溶接するコンデンサ式溶接方法であって、
前記溶接用コンデンサに充電された前記充電電荷を放電して、放電電流が前記放電用スイッチを通して実質的に流れない状態になると、前記溶接トランスの前記1次巻線を流れていた励磁電流は前記2次巻線に転流し、前記2次巻線に前記励磁電流が流れている状態で前記第1の溶接電極と前記第2の溶接電極との間を開放するときには、駆動信号を与えて前記放電用スイッチをオンできる状態にし、
前記第1の溶接電極と前記第2の溶接電極との間を開放するときに前記溶接トランスの前記1次巻線に生じるサージ電圧を前記放電用スイッチを通して前記溶接用コンデンサにサージ電流として流すことを特徴とするコンデンサ式溶接方法。 The welding capacitor is charged by the electric power supplied from the charging circuit, the discharge switch is turned on to discharge the charge charged in the welding capacitor to the primary winding of the welding transformer, and the secondary of the welding transformer A capacitor type welding method in which a welding current is applied to a workpiece through a winding and a first welding electrode and a second welding electrode connected to the secondary winding to weld the workpiece.
When the charging charge charged in the welding capacitor is discharged and the discharge current is substantially not flown through the discharge switch, the excitation current flowing through the primary winding of the welding transformer is When the space between the first welding electrode and the second welding electrode is opened while the excitation current is commutated to the secondary winding and the excitation current is flowing through the secondary winding, a drive signal is given to Make the discharge switch ready to turn on,
When a gap between the first welding electrode and the second welding electrode is opened, a surge voltage generated in the primary winding of the welding transformer is caused to flow as a surge current to the welding capacitor through the discharge switch. Capacitor-type welding method characterized by the above. - 請求項1において、
前記駆動信号は、前記溶接用コンデンサに充電された充電電荷を放電するときに前記放電用スイッチに与えられ、その後、前記第1の溶接電極と前記第2の溶接電極との間を開放するときまで少なくとも前記放電用スイッチに与えられていることを特徴とするコンデンサ式溶接方法。 In claim 1,
The drive signal is given to the discharge switch when discharging the charge charged in the welding capacitor, and then opens between the first welding electrode and the second welding electrode. Capacitor-type welding method characterized in that at least the discharge switch is provided. - 請求項1において、
前記駆動信号は、前記溶接用コンデンサに充電された充電電荷を放電するときに前記放電用スイッチに与えられた後、前記駆動信号は前記放電用スイッチに与えられなくなり、前記第1の溶接電極と前記第2の溶接電極との間を開放する直前には少なくとも前記放電用スイッチに与えられることを特徴とするコンデンサ式溶接方法。 In claim 1,
After the drive signal is given to the discharge switch when discharging the charge charged in the welding capacitor, the drive signal is no longer given to the discharge switch, and the first welding electrode and A capacitor type welding method, wherein the capacitor type welding method is applied to at least the discharge switch immediately before opening the gap with the second welding electrode. - 請求項1から請求項3のいずれかにおいて、
前記第1の溶接電極と前記第2の溶接電極との間を開放するときに前記放電用スイッチがオンすることによって前記溶接用コンデンサに充電される前記サージ電流による電荷は、前記放電用スイッチと逆並列に接続されたエネルギー回収用スイッチを通じて前記溶接用コンデンサに蓄積され、次の周期の前記充電電荷の一部分になることを特徴とするコンデンサ式溶接方法。 In any one of Claims 1-3,
When the discharge switch is turned on when the gap between the first welding electrode and the second welding electrode is opened, the charge due to the surge current charged in the welding capacitor is A capacitor-type welding method, wherein the capacitor-type welding method is stored in the welding capacitor through an energy recovery switch connected in reverse parallel and becomes a part of the charged charge in the next cycle. - 開閉機能を有する充電回路と、該充電回路から給電される電力によって充電される溶接用コンデンサと、前記溶接用コンデンサの充電電荷を放電する放電用スイッチと、1次巻線と2次巻線とを有する溶接トランスと、前記2次巻線に接続された第1の溶接電極と第2の溶接電極とを備え、前記放電用スイッチがオンするとき前記溶接用コンデンサの前記充電電荷を前記1次巻線に放電し、前記2次巻線及び前記第1の電極と前記第2の電極とを介して溶接電流を被溶接物に通電して、該被溶接物を溶接するコンデンサ式溶接装置であって、
前記溶接トランスの前記2次巻線に励磁電流が流れている状態で前記第1の溶接電極と前記第2の溶接電極との間を開放するときに、前記放電用スイッチをオンできる状態にするための駆動信号を前記放電用スイッチに与えるコントローラを備え、
前記第1の溶接電極と前記第2の溶接電極との間を開放するときに、前記溶接トランスの前記1次巻線に生じるサージ電圧を前記放電用スイッチを通して前記溶接用コンデンサにサージ電流として流すことを特徴とするコンデンサ式溶接装置。 A charging circuit having an opening / closing function, a welding capacitor charged by electric power supplied from the charging circuit, a discharging switch for discharging a charging charge of the welding capacitor, a primary winding and a secondary winding, A welding transformer having a first welding electrode and a second welding electrode connected to the secondary winding, and when the discharge switch is turned on, the charging charge of the welding capacitor is changed to the primary winding. A capacitor-type welding apparatus that discharges to a winding, energizes a workpiece with a welding current through the secondary winding and the first electrode and the second electrode, and welds the workpiece. There,
When the gap between the first welding electrode and the second welding electrode is opened in a state where an excitation current is flowing in the secondary winding of the welding transformer, the discharge switch can be turned on. A controller for supplying a drive signal for the discharge switch,
When the gap between the first welding electrode and the second welding electrode is opened, a surge voltage generated in the primary winding of the welding transformer is caused to flow as a surge current to the welding capacitor through the discharge switch. Capacitor-type welding equipment characterized by that. - 請求項5において、
前記放電用スイッチと逆並列にエネルギー回収用スイッチが接続され、
前記第1の溶接電極と前記第2の溶接電極との間を開放するときに前記放電用スイッチがオンすることによって前記溶接用コンデンサに充電される前記サージ電流による電荷は、前記サージ電流とは逆向きの電流を流す前記エネルギー回収用スイッチを通じて前記溶接用コンデンサに回収されることを特徴とするコンデンサ式溶接装置。 In claim 5,
An energy recovery switch is connected in antiparallel with the discharge switch,
When the gap between the first welding electrode and the second welding electrode is opened, the charge due to the surge current charged in the welding capacitor by turning on the discharge switch is the surge current. Capacitor-type welding apparatus, wherein the welding capacitor is recovered through the energy recovery switch for passing a reverse current.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020147001959A KR101676927B1 (en) | 2011-09-01 | 2012-08-27 | Capacitor type welding method and welding device |
CN201280039834.2A CN103781583B (en) | 2011-09-01 | 2012-08-27 | Condenser type welding method and welder |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011190824A JP5551664B2 (en) | 2011-09-01 | 2011-09-01 | Capacitor-type welding method and welding apparatus |
JP2011-190824 | 2011-09-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013031717A1 true WO2013031717A1 (en) | 2013-03-07 |
Family
ID=47756206
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/071556 WO2013031717A1 (en) | 2011-09-01 | 2012-08-27 | Capacitor type welding method and welding device |
Country Status (4)
Country | Link |
---|---|
JP (1) | JP5551664B2 (en) |
KR (1) | KR101676927B1 (en) |
CN (1) | CN103781583B (en) |
WO (1) | WO2013031717A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108067720A (en) * | 2018-01-09 | 2018-05-25 | 临沂市金立机械有限公司 | A kind of energy storage welding procedure for muffler |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2019181513A1 (en) * | 2018-03-20 | 2019-09-26 | 本田技研工業株式会社 | Welding device |
CN109158732A (en) * | 2018-09-13 | 2019-01-08 | 安徽康佳同创电器有限公司 | A kind of smell sensor welder and welding method |
JP6849174B1 (en) * | 2020-02-06 | 2021-03-24 | 株式会社オリジン | Manufacturing method of joining equipment and joined members |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5298650A (en) * | 1976-02-13 | 1977-08-18 | Nichicon Capacitor Ltd | Condencer type welding machine |
JPH0756137Y2 (en) * | 1990-10-05 | 1995-12-25 | オリジン電気株式会社 | Resistance welding equipment with after-flash prevention function |
JP2004167541A (en) * | 2002-11-20 | 2004-06-17 | Origin Electric Co Ltd | Capacitor type resistance welding machine |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0835713A1 (en) * | 1996-09-11 | 1998-04-15 | Miyachi Technos Corporation | Method and apparatus for controlling resistance welding |
JP4420520B2 (en) * | 2000-03-23 | 2010-02-24 | ミヤチテクノス株式会社 | Resistance welding power supply |
CN1186165C (en) * | 2001-09-25 | 2005-01-26 | 哈尔滨工业大学 | No secondary commutating D.C. resistance welding machine and its control method |
CN101024259A (en) * | 2006-02-20 | 2007-08-29 | 镇江市天华机电产品有限责任公司 | Two-way discharge energy-storage resistance welder |
CN201161330Y (en) * | 2008-01-09 | 2008-12-10 | 东莞市特龙金科能源科技有限公司 | Impulse current spot welder |
GB2464514A (en) * | 2008-10-16 | 2010-04-21 | Macgregor Welding Systems Ltd | Capacitor discharge welding apparatus and method |
-
2011
- 2011-09-01 JP JP2011190824A patent/JP5551664B2/en active Active
-
2012
- 2012-08-27 CN CN201280039834.2A patent/CN103781583B/en active Active
- 2012-08-27 WO PCT/JP2012/071556 patent/WO2013031717A1/en active Application Filing
- 2012-08-27 KR KR1020147001959A patent/KR101676927B1/en active IP Right Grant
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5298650A (en) * | 1976-02-13 | 1977-08-18 | Nichicon Capacitor Ltd | Condencer type welding machine |
JPH0756137Y2 (en) * | 1990-10-05 | 1995-12-25 | オリジン電気株式会社 | Resistance welding equipment with after-flash prevention function |
JP2004167541A (en) * | 2002-11-20 | 2004-06-17 | Origin Electric Co Ltd | Capacitor type resistance welding machine |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108067720A (en) * | 2018-01-09 | 2018-05-25 | 临沂市金立机械有限公司 | A kind of energy storage welding procedure for muffler |
Also Published As
Publication number | Publication date |
---|---|
JP5551664B2 (en) | 2014-07-16 |
CN103781583A (en) | 2014-05-07 |
KR101676927B1 (en) | 2016-11-16 |
CN103781583B (en) | 2016-01-20 |
JP2013052402A (en) | 2013-03-21 |
KR20140053982A (en) | 2014-05-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5457912B2 (en) | Capacitor resistance welding machine | |
WO2010137278A1 (en) | Inverter control device and inverter control method | |
JPH06234072A (en) | Inverter power supply for welding | |
WO2013031717A1 (en) | Capacitor type welding method and welding device | |
KR101626698B1 (en) | Capacitor-type welding device and capacitor-type welding method | |
JP5513249B2 (en) | Capacitor resistance welding machine | |
KR101580072B1 (en) | Capacitive welder and method for charging same | |
JPH0367476B2 (en) | ||
JP4037247B2 (en) | Capacitor resistance welding machine | |
Lebedev et al. | Transistor power sources for electric arc welding | |
WO2010023709A1 (en) | Welding machine power supply apparatus and welding machine | |
JP5996377B2 (en) | Power supply for arc welding | |
JP2005347212A (en) | Abnormal discharge restraining device for vacuum device | |
JP4436077B2 (en) | Arc start control method for consumable electrode gas shielded arc welding | |
JP3607334B2 (en) | AC / DC dual-purpose arc machining system | |
JP2012223785A (en) | Capacitor type resistance welding machine | |
JPS6128431B2 (en) | ||
SU1382615A1 (en) | Power supply source for arc welding | |
CN107442894A (en) | Condenser type welder | |
JPH0459189A (en) | Capacitor type spot welding machine | |
JPH04167981A (en) | Inverter type resistant welder | |
JPH0436789B2 (en) | ||
JP2017042800A (en) | Power supply unit for resistance spot welding |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12826913 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20147001959 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 12826913 Country of ref document: EP Kind code of ref document: A1 |